What is Arthritis?
Arthritis is a condition that can affect any joint in the body.
A simple joint forms between the ends of 2 bones and is the structure that allows movement – ie The Hip joint is where the Pelvis bone (containing the socket) interfaces with the Femur/Thigh bone (the top end of which forms the ball).
The joint surface is a specialized layer of gristle like tissue 2-3 mm thick that sits on the end of the bone. The scientific name for this layer is articular cartilage. This tissue acts like a shock absorber and reduces load on the bone beneath. It also has a very low friction characteristics which allows the surfaces to glide easily over each other.
Arthritis is where there is loss (partial or complete) of this joint surface layer. This loss is usually progressive and ultimately leads to a situation where the bone is exposed or uncovered resulting in “bone on bone” contact – this is the situation in an advanced or end stage arthritis. A good analogy for arthritis is a car tyre where the tread has worn down.
The main symptom associated with arthritis is pain. The exact cause of pain in arthritis is uncertain and probably multifactorial. Bone is a very sensitive tissue with lots of nerve endings – a broken bone is usually very painful. When the bone is not properly protected by a damaged joint surface, the bone is subject to more load and stress, which can cause pain. The wear debris created by joint surface damage floats around the joint and irritates and inflames the lining tissue of the joint (synovial lining) which also can be a contributory cause for pain.
Osteoarthritis of the Hip
Osteoarthritis of the hip, like all forms of arthritis, is due to a loss of the cushioning joint surface tissue (articular cartilage) that covers the ends of the bones of the joint – the femoral head (ball) and the acetabulum of the pelvis (socket). This is a progressive condition and the natural history is one of slow deterioration – as the articular cartilage loss increases, so usually do the symptoms. When the articular cartilage layers are worn away completely, the joint articulates with “bone on bone” surfaces – this is usually very painful (as the bone has lots of nerve endings) and constitutes an advanced osteoarthritis. Osteoarthritis differs from inflammatory arthritis in that the articular cartilage loss is due to “wear and tear” (a degenerative process – osteoarthritis is also known as degenerative arthritis) rather than due to an inflammatory process.
In most cases hip osteoarthritis is idiopathic (primary hip OA) – this means that there is no identifiable reason as to why it has arisen. Clearly as we get older there tends to be more natural wear of the joint surfaces (similar to the tread on a car tyre) but some hips never become arthritic despite advanced age. Presumably this has to do with the durability of the articular cartilage, which is probably genetically predetermined. Interestingly hip osteoarthritis can run in families. Similar to the car tyre analogy, lots of activity (driving) may predispose some individuals to more joint surface wear. It has been established for some time now that obesity is a major risk factor for the development of lower limb joint arthritis – there are both excessive load and chemical theories for this.
In some cases there are clearly identifiable reasons why osteoarthritis has occurred (secondary hip OA). The car tyre analogy here is that tread wear is more significant when the wheel balancing is poor. Predisposing conditions include congenital abnormalities of the hip (dysplasia or dislocation) which have affected the growth and shape of the ball or socket leading to abnormal and excessive wear. Conditions affecting the growth of the hip in childhood (eg Perthes disease or Slipped Upper Femoral Epiphysis) also alter the shape of the hip. Injury to the hip like a traumatic dislocation can damage the joint surface directly starting the wear process. Conditions such as osteochondritis can lead to joint surface damage and secondary OA.
In recent years, a condition called Femoroacetabular Impingement (FAI) has been recognized as a possible cause for osteoarthritis – it is thought to be a factor in some cases of primary hip OA, where previously no other cause had been identified. Again FAI is caused by subtle changes in the shape of the ball and socket leading to a slight joint surface mismatch, which over a long period of time is thought to lead to joint surface wear. Over the next decade long term studies should be able to determine whether this is the case and whether treating FAI in its early stages may prevent arthritis developing in patients with this condition.
The main symptom/complaint with hip osteoarthritis is pain. This is usually located in the groin or the front part of the hip and can sometimes be misdiagnosed early as a “groin strain”. There can be pain that radiates down the front of the thigh to the level of the knee. Occasionally patients with hip arthritis will present mainly with pain around the knee – this is obviously confusing for everyone concerned. Pain located mainly in the buttock or the back of the thigh is rarely due to hip arthritis. In most cases, the pain comes on gradually without an obvious injury or incident. At the start the pain may only occur with or after heavy physical exertion like running, but as the condition progresses the pain may be felt with normal day to day walking and when end stage is often felt at rest. Patients will often notice difficulty bending down to put on socks and shoes and attend to toenails and often have difficulty getting in and out of the car.
Hip osteoarthritis is often diagnosed on the basis of history and clinical examination. It is usually easily confirmed on plain xray, but sometimes more extensive investigations like MRI scan can be helpful particularly in the early stages of the condition.
Hip osteoarthritis is a complex condition and there are no treatments that will reverse the joint surface wear changes once they have started to take place. The treatment or management of osteoarthritis of the hip needs to be tailored to each individual depending on the severity of the condition and how this is affecting the person afflicted. In the early phases of this condition when the symptoms are mild, conservative or non-operative treatment is usually recommended. Conservative management principles centre around education of the condition, activity and lifestyle modification, weight reduction, the use of physical aids and the careful use of medication for symptom reduction or relief. These measures are about making it easier to manage with the symptoms (usually pain and stiffness) on a “day to day” basis.
Operative management or surgery for osteoarthritis of the hip is really only indicated for end stage “bone on bone” joint surfaces. Surgery for early or middle stage disease in most cases does not significantly improve symptoms or function. Total Hip Replacement (THR) is generally the treatment of choice for advanced hip osteoarthritis with unmanageable pain and very significant impairment of function (ability to walk, bend and undertake simple activities of daily living). It should be noted that THR is a compromise operation and will never provide the recipient with a completely normal hip. THR is however generally very successful in providing significant pain relief and restoration of function in a significantly impaired individual with end stage disease.
Inflammatory Arthritis of the Hip
Inflammatory Arthritis of the hip, like all forms of arthritis, is due to a loss of the cushioning joint surface tissue (articular cartilage) that covers the ends of the bones of the joint – the femoral head (ball) and the acetabulum of the pelvis (socket). The end result is the same as that of osteoarthritis – with progressive loss of articular cartilage, ultimately leading to a “bone on bone” arthritis situation.
Inflammatory Arthritis differs from Osteoarthritis (OA) in the way that the articular cartilage layer is lost. Inflammatory arthritis frequently has an auto-immune basis – meaning that cells and molecules (antibodies) that would normally protect the body tissues, instead start to attack certain tissues (the synovial lining of the hip) which in turn releases chemical factors that actively “digest” the articular cartilage surfaces of the joint. Using the car tyre analogy – osteoarthritis is tread wear caused by driving thousands of kms, whereas inflammatory arthritis is akin to throwing acid onto the tyre surface which actively eats away the tread.
Conditions associated with inflammatory arthritis of the hip include Rheumatoid Arthritis, Psoriatic Arthritis and Systemic Lupus Erythematosus. Crystal deposition diseases such as gout can lead to arthritis.
Symptomatically inflammatory arthritis of the hip causes the same symptoms as osteoarthritis – pain, stiffness and reduced function for activity/walking. The examination findings also are the same as for OA, but frequently the picture on xray is a little different.
Figure 1. Xray of hip with inflammatory arthritis – complete loss of joint space, bone cysts and absence of bone spurs (osteophytes).
The treatment principles for inflammatory arthritis and OA of the hip are very similar, with conservative measures being appropriate in mild and moderate forms of the disease – namely education, lifestyle and activity modification, weight reduction if appropriate, the use of physical aids and medication with simple analgesics and non steroidal anti-inflammatories being the mainstay. Immunosuppressive or disease modifying medications and corticosteroids can sometimes be helpful, but should only be taken after consultation with and recommendation by a specialist rheumatologist.
Similar to OA, surgery is only indicated for patients with end stage arthritis (bone on bone contact) and unmanageable pain and significantly impaired function. Total Hip Replacement (THR) is the treatment of choice in this situation, as it is generally very successful in providing pain relief and restoring function.
Avascular Necrosis of the Femoral Head
Avascular Necrosis (AVN) of the hip occurs when the blood supply to the bone of the femoral head (the ball part of the hip joint) is disrupted. This typically leads to death of the bone cells (osteocytes) in a localized area of the top of the femoral head/ball leading to collapse of the affected bone and its associated joint surface. This irreversible damage generally leads to a progressive arthritis (often quite rapid) of the hip with pain, stiffness and loss of function for walking, bending etc.
AVN is a much less common condition affecting the hip than either osteoarthritis or inflammatory arthritis. In saying this AVN can affect the bone around other joints such as the knee and shoulder, but the hip is the most common joint with this condition.
In most cases, the cause of this loss of blood supply is unknown or termed “idiopathic”. There are however a number of risk factors that make it more likely for someone to develop this condition:
A. Traumatic Injury – Hip dislocations and certain types of hip fracture can damage the blood supply to the femoral head.
B. Alcohol Intake – Excessive alcohol consumption over a long period of time can be a causative factor. It is not known how this occurs.
C. Corticosteroid Medication – Cortisone/Prednisolone medications for treatment of airways disease or inflammatory arthritis/bowel disease or other conditions. Long term use carries a higher risk of developing AVN but even short term relatively high dose administration has been associated with this condition. Again it is not known how these drugs lead to AVN. Chemotherapy agents (used to treat various cancers) can lead to the development of AVN in a similar manner.
D. Other Medical Conditions – Blood disorders like Thalassaemia and Sickle Cell Disease and Metabolic conditions like Gauchers disease can cause small clots to form in the tiny arteries supplying blood to the femoral head thereby blocking blood flow to part of the bone. An unusual condition called Caisson’s Disease (seen in deep sea divers experiencing “the bends”) causes the release of nitrogen bubbles into the arterial circulation which can block the blood vessels of the femoral head in a similar manner. There are many other conditions which can be associated with AVN of the Hip but they are quite rare.
AVN of the hip usually occurs in adults in the range from 50-70 years but can occur at any age, even in children occasionally. AVN of the hip develops in stages and early on there are often no symptoms with the condition only being picked up incidentally on a scan or other radiological investigation. As the condition progresses and there are bone changes, most patients will experience pain which is usually felt in the groin area but may radiate into the thigh or very occasionally into the buttock. Once the bone of the femoral head starts to collapse, the pain usually starts becoming more severe affecting all weight bearing activities but also occurring with leg movements and bending. With end stage AVN, the hip is often painful at rest, movement is restricted and activity is severely limited. AVN can progress through these stages quite rapidly over a period of just a few months or it may take 12 – 18 months. This is in contrast to osteoarthritis of the hip which is a generally slowly progressive condition that takes years to develop.
The diagnosis of AVN of the Hip is usually made after obtaining xrays or scans of the hip but sometimes can be quite difficult. The diagnosis may be suspected in a patient with a painful hip with restricted movement who may have one of the recognized conditions or risk factors (outlined above) sometimes associated with AVN. Plain xrays of the hip will usually show bone changes (increased density or whiteness of the bone in a localized segment of the femoral head, early collapse – a crescent sign or more advanced collapse) once the condition is established. Nuclear bone scans will sometimes pick up this condition but are often non specific. MRI scan is probably the gold standard investigation for this condition if it is suspected but plain xrays of the hip are normal. MRI has the capability to pick up very early stage AVN before symptoms have started as well as more advance disease and is useful for determining how much bone is involved by the condition. It is also extremely useful for evaluating the opposite hip for this condition as AVN can develop in both hips, particularly in those individuals where a systemic or general risk factor is present ie alcoholism, steroid use, blood conditions etc.
The treatment of avascular necrosis depends on a number of factors – individual factors, how much bone is affected and most importantly the stage of the condition. Whilst non operative or conservative measures may be appropriate for some patients with AVN, most will require some form of surgical intervention. Painkilling/analgesic and anti-inflammatory medications and the use of crutches can reduce the symptoms and possibly slow down the progression of AVN, but rarely result in resolution. Sometimes these measures are used when the diagnosis is not clear – it can sometimes be difficult to differentiate AVN of the hip from transient idiopathic osteoporosis (TIO) or stress/insufficiency fractures of the femoral head. Follow up with serial MRI scans is usually required to ascertain the correct diagnosis.
Surgical treatment involves either a procedure called Core Decompression (also known as a “forage” procedure) or Total Hip Replacement.
Core Decompression is a procedure that involves the drilling of one large or several small holes into the affected area of the femoral head to relieve pressure within the bone and to create channels for new blood vessels to grow into the “avascular” bone in an attempt to re-establish a new blood supply. This procedure is only relevant when AVN is diagnosed in its very early stages – often before symptoms and certainly before changes are seen on plain xray. Unfortunately this procedure is not successful in all cases. Sometimes bone grafting is undertaken in addition to decompressive surgery to try and lessen the chances of bone collapse but so far this has not conclusively been shown to improve outcomes in AVN.
Unfortunately for the majority of patients diagnosed with AVN of the hip, Total Hip Replacement (THR) remains the only treatment that is able to satisfactorily deal with the damaged bone and joint surface of the femoral head. Similar to end stage osteoarthritis, it involves replacing the ball and the socket of the joint with artificial implants which have bearing surfaces which provide for generally very satisfactory pain relief, restoration of movement and significant improvements in function (walking, bending and activities of daily living/simple recreations etc.). THR is regarded as one of the most successful operations in all of medicine.
Transient Idiopathic Osteoporosis of the Hip
Transient Idiopathic Osteoporosis (TIO) is an unusual condition that most commonly affects the hip joint but can affect other joints such as the knee in particular. Unlike normal osteoporsis which untreated is a progressive, irreversible condition, TIO is, as its name implies, a condition that is transient and resolves itself after a period of time, usually several months up to a year. Idiopathic refers to the fact that we don’t understand why this condition occurs and osteoporosis is a condition where the mineral content and volume of the bone reduces making it weak and susceptible to fracture. TIO of the hip generally affects both men and women between the ages of 45 and 75 but can also occur in women in the later stages of pregnancy.
Classically it starts as pain in the groin or lateral (outside) aspect of the hip which can radiate down the thigh to the level of the knee in some individuals. There is no injury or incident usually at the onset of symptoms. This pain worsens over a period of several weeks and can become quite intense. It is generally worse with weight bearing and often causes a significant limp and restricts walking ability. Whilst rest usually improves the pain, in severe cases pain can be present at rest. Examination of the hip by a medical practitioner identifies significant irritability and sometimes restriction of movement of the hip joint.
The diagnosis of TIO is made by excluding other causes of hip or groin pain and by characteristic bone changes identifiable on MRI scanning. Plain xrays are important to rule out arthritis and stress fractures but in most cases are completely normal. MRI scans of the hip joint show some diffuse changes in the bone of the femoral head, which in combination with a history of pain without an injury leads to diagnosis. It can however in some cases be difficult to differentiate TIO from avascular necrosis of the femoral head (see section on this condition) and from stress fractures of the femoral neck/head region, although these usually occur in individuals who are undertaking increased weight bearing activity
L) Normal Hip
R) Bone changes in femoral head in TIO
TIO generally resolves over a period of months (3 – 12) without any specific treatment. When the hip is painful, simple painkillers may be helpful and the use of crutches can help both pain and protect the bone from damage whilst it is in a weakened state. Simple exercise to maintain flexibility and strength of the hip girdle muscle groups (gluteals, flexors and core) can be undertaken once the acute pain subsides. Aquatic exercises can be very helpful in this regard.
Trochanteric Pain Syndrome
Trochanteric Pain Syndrome (TPS) refers to conditions that lead to pain over the greater trochanter of the upper femur (thigh bone) – this is the bony prominence on the outside of the hip. Most commonly this involves inflammation of one of the bursae (bursitis) of the hip but other tissues in the area can be affected. The bone of the trochanter itself can be a source of pain (fractures, local bone lesions), the gluteal tendons which insert into the trochanter (tendinopathy, tendon tears, calcific tendinopathy) and the fascial tissue of the outside of the thigh – the fascia lata/iliotibial band complex – (fascial tightness, “snapping” hip). TPS can result from a problem with one of these tissues or can be due to multiple local tissue pathologies acting in concert.
A bursa is a filmy sac of tissue that contains a tiny amount of fluid. It acts as a cushion that protects the bone from excessive pressure from overlying moving soft tissues. Bursa are present in the body wherever there are bony prominences close to joints – over the front of the knee (pre-patellar bursa), over the point of the elbow (olecranon bursa) and over the side of the shoulder (subdeltoid bursa). On the outside of the hip, there are 2 bursae – the superficial trochanteric bursa which protects the bone from the fascia lata/iliotibial band and the deeper subgluteal bursa which lies between the gluteal tendons and the bone. The term “trochanteric bursitis” refers to inflammation of one or both of these 2 lateral hip bursae.
The cause of trochanteric bursitis is idiopathic in most cases – this means there is no identifiable reason. Idiopathic trochanteric bursitis occurs most commonly in females (? Increased pelvic width compared with males), in older age groups (50 -75 years – associated with degenerative soft tissue changes) and there is unquestionably an association with obesity (increased soft tissue load with weight bearing activity). Tightness of the fascia lata/iliotibial band complex can be identified in many patients with this condition. Trochanteric bursitis can occur after trauma to the outside of the hip (a fall or direct blow) or after lying on the side of the hip for a prolonged period. Inflammatory conditions such as rheumatoid arthritis can cause local bursal inflammation. Bone spurs on the trochanter and calcium deposits in the bursa itself can lead to bursitis. Bursitis can follow hip surgery, particularly hip replacement and hip fracture fixation.
Gluteal tendon abnormalities can cause trochanteric pain, but rarely in isolation. The gluteus medius tendon attaches to the superficial surface of the greater trochanter whereas the gluteus minimus tendon attaches to the deep surface. The gluteus maximus tendon inserts into the upper part of the femur and is not usually implicated in TPS. Tendon tears can be a result of an acute injury (generally younger athletic individuals) but much more commonly are part of a degenerative process that occurs with ageing. Internal degeneration of intact tendons (tendinopathy) can be present and degenerative tendon tears are very common in individuals above the age of fifty – only a small proportion of these are actually painful – probably a result of an associated bursitis or impingement (abnormal contact or pinching) against the overlying fascial tissue.
Snapping hip is generally a condition that affects young and generally athletic/active females. It is caused by the fascia lata/iliotibial band, which is a large sheet of fibrous tissue on the outside of the leg, snapping or audibly rubbing against the greater trochanter with repeated flexion and extension of the hip. This snapping may or may not be painful. The bursa can be caught in between and become inflamed as part of a “friction” type syndrome.
Trochanteric Pain Syndrome is characterised by pain over the lateral aspect or “point” of the hip. It can radiate sometimes along the outer aspect of the thigh or into the buttock. It is usually dull and aching but the outside of the hip can be quite tender to touch. Generally this causes most trouble at night when lying on the affected side – which is either not possible at all or only for a very short time. Some individuals find they are unable to lie on the opposite side for any period – this position will also cause pain to arise in the affected hip. This nocturnal pain can cause major disruption to sleep and is often the main driving reason for seeking treatment. Pain can be present with sitting, particularly when driving for significant distances. When bad, pain can be present even with walking, stair climbing or any activities involving repetitive hip flexion and extension.
Examination of an individual with suspected TPS should include an observation of gait, palpation over affected site for the extent of tenderness, assessment of the range of motion of the hip (noting painful positions) and the strength of the various muscle groups supporting the hip, particularly the gluteal muscles. A test for fascial tightness is very helpful and this maneouvre will often reproduce pain typical of TPS. Snapping of the fascia over the greater trochanter can often be demonstrated by the individual, if present.
Radiological investigations are very helpful in determining the tissues involved and their pathologies in each case of TPS. Plain xrays are important for ruling out hip joint disease but also show any irregularities on the external surface of the greater trochanter, together with calcific deposits in the adjacent soft tissues and any local bone lesions within the trochanter itself. Ultrasound is a popular investigation but does have significant limitations. It may reveal fluid in the trochanteric bursa and can demonstrate tendon pathology, but its diagnostic accuracy is variable. MRI is the investigation of choice as it can show all forms of pathology in both the soft and bony tissues of the trochanteric region as well as the hip joint itself.
The natural history of TPS, even if untreated, is usually one of slow resolution over a period of months to years. The treatment of TPS may change slightly depending on the diagnosis as to the cause/pathology present, but in general follows some basic principles. In almost every case, conservative or non-operative treatment is the appropriate first line management. It may seem obvious, but avoidance of situations that cause pain is essential – continuing with painful activity will never allow this condition to settle. This usually means adopting a comfortable sleeping position at night – avoiding lying on the affected side, putting a pillow between the legs if lying on the opposite side or lying on the back to avoid direct pressure on the painful area. Correction of associated underlying conditions – weight loss in obese individuals and rheumatological review/treatment of established generalized inflammatory disorders when present (eg. rheumatoid arthritis) is very important. Local physical treatment in the form of stretches to the fascia lata/ilio-tibial band complex and gentle eccentric gluteal and core strengthening can be very helpful, particularly when able to be undertaken comfortably. Instruction from a therapist regarding the use of a foam roller or similar device over the trochanter and fascia can complement an exercise program. Analgesic medication and local heat can reduce the pain of TPS. Non-steroidal anti-inflammatory drugs (NSAIDs) can be useful in inflammatory tendon/bursal conditions. Cortisone injections into the trochanteric and subgluteal bursae (under ultrasound control to ensure accuracy of delivery) are often more effective than NSAIDs and don’t generally have the same potential for side effects. Reducing pain in this way to enable satisfactory participation in a stretching/strengthening exercise program can be one of the keys to successful treatment. Sometimes multiple cortisone injections are required, spread out over a period of time. Injections of autologous blood (patients own blood) or platelet rich plasma may be indicated in TPS where tendinopathy/tendon tears seem to be the predominant pathology.
Surgical treatment of TPS is rarely required or indicated. Surgery unfortunately is not always successful and it is impossible to predict the outcome pre-operatively. Recovery is generally slow and often involves a period of non-weight bearing on crutches followed by an extensive rehab/physiotherapy program together with a lot of patience. Despite undertaking all the correct steps, a proportion of individuals with TPS undergoing surgery will still continue to have pain and functional limitation. If surgery is to be undertaken, identification of all the pathologies involved and addressing each of these with the operative procedure is important. Surgery clearly carries some risk – infection, deep vein thrombosis, nerve or vessel damage and anaesthetic complications are possible – and is always absolutely a last resort attempt at symptom improvement in most cases of TPS.
Loose Body of the Hip
The hip, like any other joint in the body, can be affected by loose bodies. These loose bodies may be cartilaginous or bony, but are most often a combination of both – these are referred to as osteochondral (osteo = a bony core and chondral = a cartilage surface) loose bodies.
There are a number of conditions that can lead to loose bodies forming within the hip joint. Traumatic dislocations of the hip can be associated with fractures of either the femoral head (ball) but more commonly of the edge of the acetabulum (socket) and as a result small fracture fragments can break off the joint surface and become loose and potentially trapped in the joint.
Osteoarthritis can be a cause of loose bodies – presumably osteophytes (bony spurs around the margins of the joint) break off and can become loose inside the hip. A somewhat unusual condition called osteochondritis dissecans can affect the joint surface and underlying bone of the femoral head (ball) of the hip. In its advanced stages a small part of the surface can detach and float free in the hip. In a condition called synovial osteochondromatosis – multiple and sometimes hundreds of small loose bodies can arise like “mushrooms” from the synovial lining of the hip and are shed into the joint.
Loose bodies can vary in size from tiny to very large and their size tends to dictate what kinds of problems they can cause. Small loose bodies may cause no trouble at all, mid size ones tend to float/move around inside the joint and can get stuck from time to time causing intermittent locking or jamming of the hip. Very large loose bodies frequently can’t move around freely in the joint but in some circumstances can restrict movement in a similar way to hip impingement conditions.
Symptomatic loose bodies of the hip are best treated by removal – either by open operation (for very large loose bodies) or by arthroscopic (minimally invasive) means in most cases. It is also important to treat any joint surface defect associated with the origin of the loose body. Definitive treatment of loose bodies associated with synovial osteochondromatosis is almost impossible because new bodies will tend to form again with time. Synovectomy of the hip may address this problem but it is difficult to remove all synovial tissue from the hip because of its complex joint geometry.
Labral Tear of the Hip
The acetabular labrum is a fibrocartilaginous structure that sits around the rim of the socket of the hip. It is triangular in cross-section. It is very similar tissue in structure to the glenoid labrum of the shoulder and the meniscus (“cartilage”) of the knee and is colloquially known as the “cartilage” of the hip.
Similar to the meniscus of the knee (which has been extensively studied), the labrum of the hip performs a number of important functions for the joint. It is almost certainly involved in some way in load transmission across the surfaces of the hip and assists with the flow of lubricating synovial fluid throughout the joint. The labrum acts as a “seal” and deepens the joint – important for stability and contains proprioceptive receptors that allow impulses to be sent to the brain regarding the position of the joint and its attached leg, which is important for balance, co-ordination and injury prevention.
The labrum of the hip (again similar to the knee meniscus) has only a limited capacity for repair when damaged. The base of the labrum where it is attached to the bone of the hip socket (the acetabulum) has a blood supply that comes directly from the bone itself. Injury or tears to the labrum in this vascular zone have some capacity for healing. Unfortunately the free edge of the labrum has a very limited or poor blood supply and damage to this portion of the labrum generally results in tears that have no significant capacity to heal by themselves. The site of damage of the labrum clearly has significant implications with regard to how they are treated.
Labral tears of the hip fall into 2 main categories.
The first of these is the “acute” tear – which generally occurs in younger individuals pursuing athletic activities. In this group, there is frequently a significant injury or incident involving forced rotation or hyperabduction (“doing the splits”) of the hip. There may be a noise or sensation of damage felt within the hip or groin followed by immediate onset of pain. A proportion of these types of labral injury involve the vascular zone.
The second is the “degenerative” tear – which tends to occur in individuals over the age of 35 years and usually without a preceding injury or incident. The internal structure of the labrum “dries out” as we age – losing elasticity and flexibility – and as a result it is prone to small surface splits or damage that with time and “normal” use can progress to a significant tear. Many of these tears are asymptomatic – they cause no problems at all, even though they can be seen on investigations like an MRI scan. We know that degenerative tears of the labrum become more frequent with age and that a high percentage of the population over 65 years of age have them. If a degenerative tear of the labrum creates an unstable segment or “flap” that can move around abnormally or get caught between the ball and the edge of the socket – it can create pain inside the hip.
Labral tears of the hip cause pain and this is classically felt deep over the anterolateral aspect of the groin in what is called the “C” sign – so described because of the classical hand position used when showing the position and distribution if the pain (see figure).
This pain location corresponds with most tears (around 90-95%) of the labrum being at the front (anterior) or top (superior) of the hip. Tears of the labrum at the back of the hip (posterior) are unusual but may cause pain felt deep in the buttock. Pain is felt with significant physical activity (running & sport), often with changing direction or certain rotational movements of the leg and often when the hip is repeatedly flexed particularly under load (squats, cycling in an aerodynamic position etc.) Tears can cause clicking with various movements of the hip. This kind of clicking is usually painful. Clicking in the hip however can be due to a number of different causes, most of which are innocent. If a labral tear is of sufficient size it can cause mechanical symptoms – catching, jamming, locking or a sensation that something goes in and out of place inside the joint.
Plain xrays are a good first investigation in anyone with suspected hip pain/pathology, even though xrays are most frequently normal or may show some degenerative joint changes. The best investigation for diagnosing a labral tear is undoubtedly an MRI scan with or without intrarticular gadolinium (a contrast agent injected into the joint). In a lot of cases tears can be seen directly by the scan but sometimes only small fluid collections are seen on the external surface of the labrum – these collections are called paralabral cysts and are a strong indication that a labral tear is present. A labral sulcus – a groove or pit seen between the labrum and its attachment to the edge of the acetabulum (seen in about 35% of hips) is often mistakenly reported as a “tear” on MRI.
It should be noted that labral tears can co-exist with other hip pathology – particularly hip impingement in younger individuals and osteoarthritis in older patients – and these other pathological entities need to be considered when investigating and mapping out a treatment plan.
Not all labral tears require treatment. Assymptomatic (non painful) tears identified on MRI scan and tears associated with significant osteoarthritis do not require any specific treatment. Symptomatic (painful) tears without mechanical symptoms can be managed in some individuals without surgery, by a combination of avoidance or modification of exacerbating activity (ie altering cycling position), physiotherapy techniques to correct muscle imbalances that are often present and the use of analgesic and anti-inflammatory medication for pain relief. Conservative treatment may be indicated initially in “acute” tears where there is some prospect of spontaneous healing. Surgery in the form of hip arthroscopy is indicated in patients with painful tears unresponsive to non-operative treatment or tears with clear mechanical symptoms. Arthroscopic treatment generally involves resection of the torn segment of the labrum and smoothing of the remaining labral surface but repair of the labrum can be undertaken in cases of detachment or vascular zone tears in an otherwise healthy labrum – this unfortunately is not a common situation. As a general rule “acute” tears in healthy labral tissue tend to respond best to surgical treatment, whereas the outcome in “degenerative” tears is more variable.
FemoroAcetabular Impingement (FAI)
FAI is a complex condition that was first described about 15 years ago. Looking back now it is clear that FAI in one form or another has probably been around for hundreds, if not thousands of years.
FemoroAcetabular Impingement refers to a condition of the hip where there is abnormal contact (impingement = pinching or conflict) between the ball of the hip (femoral head) and the edge of the socket (acetabulum). This results in local damage to the tissues on the outer margin of the socket – the labrum and the adjacent socket joint surface. These damaged tissues cause hip pain and the abnormal contact between ball and socket generally leads to some restriction of hip movement. The damage created by this abnormal contact situation can become progressively larger and more severe and in theory, in some people if this is unchecked over many years, it may lead to arthritis. It is believed that a number of cases of primary osteoarthritis of the hip where the cause is unknown (idiopathic) could be due to FAI. Whilst a number of these cases of osteoarthritis display features on xray that could be consistent with FAI (anecdotal observation), at present no longitudinal scientific studies (following a group of people over many years and observing what happens to the hip) can prove this link.
What causes FemoroAcetabular Impingement?
FAI usually results from a mismatch between the ball (femoro) and socket (acetabular) of the hip. In a normal hip the ball is spherical with a convex surface and its shape is matched exactly by the concave surface of the socket. As a result with normal hip movement (flexion/extension, rotation and sideways movement or circumduction) the edge of the ball slides smoothly under the edge of the socket. FAI results when there is a variation/abnormality of the shape of the ball or socket. In this situation certain hip movements result in hard contact, rather than gliding, of the surfaces of the ball and socket – akin to the square peg in a round hole. In general, the greater the shape mismatch, the greater the impingement and the greater the potential for joint damage.
When the shape variation/abnormality is on the ball side of the joint, the condition is known as “cam” type FAI. Generally the ball is aspherical with an elliptical or oval shape. This is the most common type of FAI. When the socket has a shape variation/abnormality, this is referred to as “pincer” impingement. Here the socket is either too deep or the bony edge of the socket is prominent. Sometimes variations/abnormalities of both the socket and ball are present and this is referred to as “mixed” impingement.
Abnormalities of the shape of the ball or socket may be congenital (born with this condition) or developmental (develops in childhood or adolescence with bone growth). These abnormalities can be quantified on xray/CT scan/ MRI scan and there are various measures to signify whether the shape differences are mild, moderate or severe. Population studies have identified that at 18 years of age a significant percentage do not have spherical femoral heads (ball). Of these individuals, only a very small number go on to develop the clinical symptoms and signs associated with FAI. This is an important point because FAI is NOT a condition that is diagnosed because an xray or scan report indicates there is a shape variation to the ball or socket.
Occasionally FAI can occur in individuals with normally shaped balls or sockets. These individuals have hypermobile joints and impingement occurs when the joint is at an extreme of its range of movement.
Pathology of FAI
The damage to structures inside the hip joint in FAI is usually secondary to repeated minor trauma caused by the abnormal contact situation and is therefore “wear and tear” type damage. Occasionally an acute incident can lead to similar damage but this is far less common.
The labrum is a fibro-cartilage structure that attaches to the bony edge of the circumference of the socket. It has a number of different functions – aids in joint stability, helps with synovial fluid distribution, joint surface protection and acts as a joint seal. It has a limited blood supply and therefore has a limited healing capacity. When the labrum is damaged in FAI it is usually due to a shearing type of force, which tears the inner surface of this structure where it sits just adjacent to the socket joint surface. The repeated minor trauma to this segment of the labrum in impingement means that this structure has no opportunity to heal itself.
The other structure damaged in FAI is the socket (acetabular) joint surface where it meets the labrum at the edge of the socket. Again it is generally a shearing injury to the joint surface – a layer of gristle like tissue called articular cartilage, which is 2 – 3 mm thick and covers and protects the bone of the socket. This causes delamination (stripping a layer) of this surface which can be either partial or full thickness. This creates a flap of tissue (comprised partly of labral tissue and partly articular cartilage) that is unstable and moves abnormally with certain motions of the hip, creating pain and sometimes mechanical symptoms like catching or locking. The articular cartilage layer has no reparative capacity once damaged.
Symptoms and Signs of FAI
FAI is generally symptomatic in younger athletic individuals pursuing sports OR those in the 35-50 year age group who are generally active.
FAI causes pain that is most commonly felt in the groin often during or after sporting activity but can occur whilst sitting or with other activities that require significant hip flexion. Once established, there can be a background groin (much less frequently lateral hip or buttock) ache with sharper exacerbations and sometimes mechanical symptoms like catching or locking. Occasionally individuals will have a feeling of lacking full power in the leg when undertaking activities like cycling. Many people with FAI note reduced flexibility in the hip. Examination of the hip by a specialist will often detect loss of flexion and internal rotation range of motion and reproduction of pain symptoms with certain movements.
Investigations in FAI
Plain xrays (including a good quality lateral view) are really important, as these will often give clues as to issues with the shape of both the femoral head (ball) and acetabulum (socket). Xrays will also detect significant arthritic change.
CT scans (particularly 3D reconstructions) can sometimes be helpful for the doctor in understanding the bone shape mismatches in FAI.
The definitive investigation however is MRI scan. This complements plain xrays in terms of defining shape variations/abnormalities of the ball and socket but it can also give information about areas of bone stress, accurately reflecting the precise location of abnormal bony contact. MRI is the best current investigation for detecting tears of the labrum and damage/delamination of the adjacent socket joint surface. It is also accurate in determining the extent and severity of any arthritic change within the joint, which is an important factor in guiding treatment.
A. Hip with FAI showing cam lesion of ball, labral tear (arrow) and joint surface damage (loss of joint space adjacent to labral tear).
B. Normal Hip with spherical ball and normal labrum/joint surface.
Diagnosis of FAI
The diagnosis of FAI is based on consistency in clinical history, examination findings and radiological investigations. Plain xrays or MRI scan (and reports indicating FAI) alone cannot indicate the presence of FAI – particularly as we now recognize that shape variations/abnormalities are quite common in asymptomatic individuals.
Treatment of FAI
The goals of treatment are to relieve pain, improve function and allow a return to activity.
a) Non Surgical treatment of FAI
Not every individual with FAI requires surgery. Many people with FAI can be managed non-operatively. This requires an understanding of the condition and often modification of activities that cause symptoms (mainly pain) – examples include achieving correct bike fit and seating position and pedaling technique for affected cyclists and sometimes simple ergonomic changes to seating at work or in the car.
Analgesic and non steroidal anti-inflammatory medication can be helpful in settling background pain. Sometimes cortisone injections into the hip joint can reduce inflammation and pain but are not indicated in everyone. Once pain has been improved, physiotherapy efforts directed towards avoiding impingement producing movements, strengthening the gluteal and core muscles and stretching fascial tissue can be helpful. As a general rule, individuals with mild symptoms, minimal hip movement restriction and less severe shape abnormalities are good candidates for non-operative treatment.
b) Surgical treatment of FAI
Surgery for FAI involves 2 basic principles.
The first of these is to treat the pain causing pathology. This is the damage to the labrum (hip cartilage) and/or the socket joint surface. This involves either trimming or repair of the damaged labrum and trimming, smoothing and sometimes pseudo-repair (called microfracture osteoplasty) of the damaged socket joint surface.
The second principle is to treat shape abnormalities of the ball or socket that have created the damage to the socket margin. This generally means trimming prominent bone from the base of the ball and sometimes from the edge of the socket. This is essential to relieving the abnormal contact/impingement, which is the basis of FAI.
A. View of a cam lesion of the femoral head (edge of the ball).
B. After resection of the cam lesion to restore femoral head sphericity.
Surgery can be performed arthroscopically (a minimally invasive technique using a small surgical telescope) or by open arthrotomy ( a standard incision with surgical dislocation of the hip to access the joint) or occasionally by a combination of both techniques. The decision regarding surgical technique is based partly on the severity and extent of the problem and partly based on the preference of the surgeon. Most FAI cases requiring surgery can be managed arthroscopically but larger shape abnormalities/more marked areas of joint surface damage are sometimes best managed by open arthrotomy. Both techniques have been demonstrated to be effective in treating FAI.
Unfortunately like with any surgery, surgery for FAI is not universally successful. Outcomes are variable but people with minimal joint surface damage tend to do best. Conversely individuals who have an established arthritis with FAI have poor outcomes following surgery.
Recovery following surgery is often quite prolonged. The first 6 – 8 weeks are spent undertaking light or low impact activity only followed by gradual loading of the hip together with progressive strengthening. Running may be possible after 3 months followed by agility drills and a return to sport at around 5 – 6 months. This timeframe is a general guide but may vary from case to case.
The last word on FAI
“The impact of surgery on long term clinical results, the natural history of FAI, or the prevention of or delay in the onset of osteoarthritis has not been established. The current literature supports surgical intervention for the treatment of FAI to provide pain relief and improved function in active patients in whom osteoarthritis is not severe, but it does not support prophylactic surgical intervention in asymptomatic individuals to prevent degenerative changes of the hip.” Bedi et al. J Bone Joint Surg Am 2013: 95: 82-92.
Snapping Hip Syndrome is characterized by an audible and sometimes visible “snapping” or “cracking” sensation of the hip that generally occurs when the leg is moved in a certain way.
The most common reason for snapping hip is movement of the fascia of the outside of the leg (the fascia lata/iliotibial band complex, which extends from the side of the pelvis to the outside of the knee) over the bony prominence on the outside of the hip (known as the greater trochanter). This most frequently occurs in young athletic females who perform activities that involve repetitive flexion and extension of the hip (eg dancing/cycling). The snapping can usually be demonstrated by the afflicted individual and can usually be seen on the outside of the upper thigh. The snapping sensation is usually not painful but if the trochanteric bursa becomes inflamed as a result of friction between the fascia and the bone of the trochanter, then pain can result (see Trochanteric Pain Syndrome).
Most cases of snapping hip require no specific treatment other than reassurance that the condition is not serious and will not lead to hip joint disease in the future. If the snapping is annoying but not painful, modification of exacerbating activities combined with a program of physiotherapy for fascial stretches, gluteal strengthening and instruction regarding the use of a foam roller or similar device can be helpful. If pain is a significant issue then this can be combatted by use of analgesics, anti-inflammatories and sometimes an injection of local anaesthetic and cortisone into the trochanteric bursa.
Surgery is rarely required but is occasionally indicated in resistant painful cases. It is important to have plain xrays and probably an MRI scan to rule out local bony or soft tissue pathology in the region of the trochanter. Surgery involves release or lengthening of the fascia lata/iliotibial band which is usually very tight together with removal of any bony projections from the greater trochanter.
The second most common cause of snapping hip syndrome is a condition called coxa saltans interna. This condition is caused by the main hip flexor tendon (iliopsoas tendon) contacting the front of the socket of the hip or a bony part of the pelvis called the iliopectineal eminence. This creates snapping felt at the front of the hip or deep in the groin (as opposed to the outside of the hip), again generally with hip flexion or sometimes rotation. This snapping can be painless or painful. Other causes of snapping at the front of the hip include part of the quadriceps (the rectus femoris tendon) contacting the ball (femoral head) of the hip joint and tears of the cartilage (labrum) of the hip joint. A dynamic ultrasound investigation may enable the “snapping” structure to be identified. Treatment of snapping psoas tendon follows the same basic principles as for snapping fascia lata/iliotibial band with non-operative treatment being the mainstay and surgical release reserved for rare cases unresponsive to physical therapies.
Meralgia Paraesthetica (MP) is an unusual condition that is characterized by a burning pain and sensory abnormalities (tingling and/or numbness) affecting the outer side of the thigh.
It is caused by pressure on/compression of a nerve – the lateral cutaneous nerve of the thigh (LCNT)(also known as the lateral femoral cutaneous nerve) – as it crosses from the lower abdomen into the upper thigh. It travels through a small tunnel on the outer aspect of the inguinal ligament – a fibrous band structure that runs from the bump at the front of the pelvis above the hip (the anterior superior iliac spine) to the inner part of the groin (pubic bone). Meralgia is classically caused when the LCNT is squashed as it travels through this tunnel. As this nerve is a sensory nerve only – compression causes pain and sensation disturbance but doesn’t cause any muscle weakness/paralysis.
Meralgia paraesthetica classically occurs in middle age (40-60 years) and in both males and females. In most cases there is no identifiable cause of this condition but there are definite associations with obesity and diabetes. Direct pressure on the front of the pelvis from tight clothing (jeans and belts), seat belts in cars, tool belts and pregnancy can be implicated at times.
The main symptom in MP is burning pain over the outer aspect of the thigh, along the line of the LCNT. This is usually constant and doesn’t change with rest or activity but may be aggravated by direct pressure over the front of the pelvis.
There may be sensitivity of the skin of the thigh to light touch and sometimes tapping over the course of the nerve where it crosses the inguinal ligament can produce pain and tingling in the thigh.
MP is largely a clinical diagnosis – there are no definitive tests for this condition, although nerve conduction studies can be helpful if positive.
Treatment in the first instance usually involves an injection of local anaesthetic and cortisone delivered around the nerve as it runs through the inguinal ligament. This is generally best done by a radiologist using ultrasound to localize the nerve. This injection can be helpful in confirming the diagnosis if it eliminates the pain of MP in the first few hours whilst the local anaesthetic is working. In many patients a single injection is all that is required but sometimes its effect wears off after resolution of symptoms for weeks or months. It can be repeated if helpful initially for a reasonable period. Weight reduction, optimal control of diabetes and attention to tight clothing and seat belts etc. should be addressed if appropriate.
Surgical decompression of the nerve may be indicated in cases unresponsive or recurrent with conservative treatment. Surgery involves dividing the tissue of the roof of the tunnel, releasing pressure on the nerve as it travels through the inguinal ligament. In cases where the condition has been present for a long time, surgical decompression of the LCNT may not relieve the condition completely and numbness/tingling may persist.
Stress Fracture of the Femoral Neck
Stress fracture of the hip is an unusual condition that generally occurs in athletic individuals who begin or significantly increase running/other impact activity. The fracture itself usually occurs in the femoral neck at the base of the ball of the hip joint. Sometimes the fracture can occur in the bone of the pelvis adjacent to the hip and rarely in the femoral head (the ball of the hip joint). A stress fracture begins as a tiny microscopic crack in the bone which slowly increases in size with loading activity such as running. This is different to an acute fracture where there is a single incident or event (ie falling over) that causes the fracture. A stress fracture is like getting a piece of coathanger wire and bending it back and forth – eventually if this cycling continues the wire will break.
Most individuals with a stress fracture of the hip notice pain in the groin which comes on with running and activity. This pain tends to settle quickly with rest initially and recurs when attempting running again. If running is continued despite the pain then often the condition reaches a point where the pain doesn’t completely settle with rest and in some cases can be present continuously. Stress fractures occur in many bones in the body but the bones of the foot (at the extremity of a weight bearing limb) are most commonly affected.
Sometimes stress fractures can be seen and diagnosed on plain xrays but frequently scanning (CT or MRI or Nuclear Medicine) is required to be certain.
Treatment of stress fracture generally requires reversal of the reason the fracture has developed in the first place – too much activity needs to be replaced by REST of the injured limb/joint. Bone generally takes 6-8 weeks to heal and this is the period of time where crutches and non-weight bearing are required. This period can be followed by a period of progressive partial weight bearing (still with crutches) and hopefully crutches can be discarded at approx. 12 weeks. A graduated running program can be started once walking is comfortable with the aim of slowly progressing distance and possibly speed over a period of 3 months. If pain recurs at any stage in this process then activity is reduced again until the pain settles. Occasionally stress fractures of the femoral neck require surgery – these types of fracture have a particular pattern on CT/MRI scan.
A variation on the typical stress fracture of the hip is the kind of fracture seen in the upper femur which can occur secondary to osteomalacia (VitaminD deficiency), parathyroid disease and with the use of bisphosphonate drugs for the treatment of osteoporosis.
Arthroscopy of the hip
Hip Arthroscopy is a minimally invasive operative procedure which allows the treatment of a range of hip joint conditions. It can be used to treat labral (hip cartilage) tears, local areas of joint surface damage, remove loose bodies and undertake simple treatment of early arthritis conditions.
About the surgery
The procedure is usually performed as a “day case” – admitted the day of surgery and discharged from hospital a few hours after surgery. The procedure is normally performed under a general anaesthetic (GA) and for this reason fasting from food/fluid is required before surgery. You will be notified when to stop eating/drinking. You will need to be picked up from hospital by a relative or friend as you will not be able to drive home.
Hip Arthroscopy involves introduction of a small telescope into the hip joint. In order to achieve this the bones of the joint – the ball (femoral head) and socket (pelvic acetabulum) are separated by a small distance. This is done by injecting air and fluid into the hip joint under x-ray control and then applying traction to the foot through a special boot. Two small stab incisions (approximately 5mm in length) are then made over the side of the hip to facilitate firstly the introduction of the joint telescope and then a series of working micro-instruments can be inserted through the second incision. These instruments enable the surgeon to undertake appropriate corrective action relevant to the pathological conditions that may be present.
At the end of the procedure local anaesthetic is normally injected into the hip to minimise pain post operatively and the small incisions are closed with stitches and steristrips. A waterproof dressing is then placed over the area. Your surgeon will normally come and speak with you regarding the procedure before being discharged home. Sometimes the wound will be redressed in the day surgery area before being discharged – particularly if there has been any significant fluid leakage beneath the original dressing.
After the surgery
When you are discharged from hospital you should have a set of photographs from your procedure, some painkillers which will probably be required for a few days, a pair of crutches and a sheet of instructions for your physiotherapist. It is often easier to hire crutches from a local pharmacy or supplier – these are easier to return compared with hospital supplied crutches. Please bring these with you on the day of your surgery. It is not generally recommended to start physiotherapy until after post operative review by your surgeon at 10 – 14 days. If you need a certificate for work/study, please ask your surgeon on the day.
Once you get home it is generally recommended that you mainly rest for the first couple of days. It is normal to feel discomfort and sometimes swelling locally in the groin and thigh. Please use painkillers and ice for this especially in the first 48 hours. Small amounts of bleeding beneath the dressing are very common and not a cause for concern. It is advisable to use crutches to assist with walking and weight bearing activity in the first 5 – 7 days. It is usually okay to put some weight on your operative leg over this period and proceed to full weight bearing after about a week. It is also not advisable to drive in the first 2 – 3 days after surgery. After a couple of quiet days at home you may increase activity slowly as comfort permits. There are no specific exercises to follow at this point – you may move the hip/leg freely provided it is comfortable. Avoid excessive walking, prolonged standing, squatting or deep bending and any significant rotational movements of the leg. Your surgeon will advise you if there are any changes to these basic post-operative guidelines. Should you have any concerns, consult your surgeon or general practitioner.
The post operative visit is usually at 10 – 14 days after surgery. At this time your dressing and stitches will be removed and the surgical wounds inspected. Your surgeon will normally discuss with you the surgical findings and procedure, going over your surgical photographs. At this stage it is normally recommended that you start a hip rehab program under the guidance of a physiotherapist who can tailor the program to your particular condition. Heavy impact activity and sport is usually avoided in the first 6 -8 weeks but gentle low impact activity such as stationary cycling and swimming/hydrotherapy are okay once your surgical wounds are well healed. Rehab usually consists of progressively regaining range of movement of the hip, strengthening exercises to the hip girdle muscles but also to your core muscles (lower abdominals and spine) and some proprioceptive exercises (a combination of balance and coordination work).
Risks and complications
As with any operation there are potential risks and complications that can occur. Fortunately these are infrequent and hip arthroscopy is generally regarded as a relatively low risk procedure – however should a significant complication occur you could be worse off than before the procedure. There is a very small risk associated with any form of anaesthesia. Should you have any concerns in this regard, please speak to your anaesthetist who will see you before surgery. There is a small risk of infection developing in the hip and a small risk of deep vein thrombosis (blood clot) developing in the leg – the risks of both are less than 0.5 percent. There is risk of permanent damage to vessel or nerve around the hip – around 1 in 1000 cases. Short lived numbness around the hip, genitals and in the lower leg is slightly more common and if present usually lasts a few days before resolving. Unfortunately there is no procedure (hip arthroscopy included) that fixes all problems and there is a chance that you may continue to experience problems with the hip after surgery of this or any type. Occasionally a hip joint may be very stiff and if the joint cannot be separated satisfactorily, there is a small chance that the surgery will not be able to be undertaken. Despite these potential problems associated with hip arthroscopy, in most cases the surgery results in significant improvements in pain and function.
Recovery following surgery is quite variable and dependant on individual factors, the original hip condition and it’s treatment and your body’s response to exercise / physiotherapy. Your surgeon and physiotherapist should be able to guide you in this regard.
Post Operative Care Information
Hip Arthroscopy is usually undertaken making 2 or 3 small stab incisions on the outer part of the hip. These incisions are closed with stitches and steristrips and a waterproof dressing is then placed over the area. Sometimes the wound will be redressed in the day surgery area before being discharged home – particularly if there has been any significant fluid leakage beneath the original dressing. Small amounts of bleeding under the dressing are very common and not a cause for concern. You may shower with this dressing on but don’t immerse in a pool or bath. If a significant amount of moisture accumulates under the dressing it will need to be changed – otherwise leave dressing intact until seen by your surgeon at the post operative visit. Occasionally the dressing will fall off after 8 – 10 days – just keep the area dry or if concerned get your local doctor to redress this for you.
At the end of the procedure local anaesthetic is normally injected into the hip joint to minimise pain post operatively. This will wear off after a few hours and you may need to use ice packs locally and take the painkillers prescribed to you at this stage. These are often required in the first 48 hours or so but this varies from one individual to another. Short lived numbness around the hip, genitals or lower leg is uncommon but if present will usually resolve after a few days.
It is advisable to rest in the first 2 – 3 days quietly at home. Over this period you may get up and weight bear on the operated leg as comfort permits using crutches for short periods. Crutches are usually required for 5 – 7 days and you may fully weight bear after this time if comfortable. Occasionally you will need to protect weight bearing for a longer period – your surgeon will advise you if this is required.
You may move the hip / leg freely provided it is comfortable but avoid hyperflexing the hip, deep squatting or significant twisting of the operated leg in at least the first 2 weeks.
It is not advisable to drive in the first 2 – 3 days after surgery or whilst you are taking pain medication. If you can comfortably operate the accelerator/brake/clutch without pain, you may drive at your discretion.
You may return to work as soon as pain is tolerable. Generally if a job does not require prolonged standing and walking, you may return after about a week. Work of a more physical nature may necessitate a longer absence.
Physiotherapy is not usually recommended until after review by your surgeon at 10 – 14 days.
Follow Up Visit:
This has been made for you at the time of booking your surgery and is detailed on the sheet attached to the booking information you have been sent out.
Your surgeon will advise you if there are any changes to these basic post operative guidelines. Should you have any concerns, consult with your surgeon or general practitioner.
Arthroplasty of the hip
Total Hip Replacement (THR) is a surgical procedure that is arguably the most effective in all of medicine. In the right individual it can dramatically change a persons life providing improvements in pain relief and quality of life in a very cost effective way. 34,000 hip replacements were performed in Australia in 2010 and this number is increasing slowly each year.
THR is potentially indicated when the normal surfaces of a hip joint have been damaged irretrievably. The common causes for this are:
(1) Osteoarthritis – a degenerative “wear and tear” condition seen generally in adults over the age of 50 years. The cartilage cushioning layer on the surface of the ball and socket of the hip wear away leaving “bone on bone” contact causing pain and stiffness.
(2) Inflammatory Arthritis (eg Rheumatoid Arthritis) – an auto-immune disease where the synovial lining of the joint becomes chronically inflamed and the cartilage surfaces of the hip joint become progressively destroyed.
(3) Avascular Necrosis of the Hip – an unusual condition where the blood supply to the ball of the joint fails leading to collapse of the bone directly beneath the joint surface. This leads to destruction of the smooth joint surface of the ball.
(4) Fracture of the Hip – very occasionally the fracture is such that hip replacement is indicated.
These conditions cause hip girdle pain and stiffness. This generally affects all weight bearing activity including walking, standing and all manner of recreational activity, rising from a seated position and tasks that involve bending such as getting shoes and socks on and off. If conservative treatment in the form of medications, changes in everyday activities, weight reduction if appropriate and the use of walking aids do not help the pain and stiffness, then hip replacement may be appropriate. In these circumstances hip replacement can provide pain relief, increase in hip motion and allow a return to normal daily activities including some simple exercise/recreations. Hip replacement surgery however is generally last resort treatment in a patient who has severe symptoms, advanced “bone on bone” disease in whom there is little prospect of improvement.
Conventional Total Hip Replacement involves replacing the worn surfaces of the hip joint with an artificial socket and ball. The new socket or acetabular component can be one piece but nowadays is most commonly a two piece device – consisting of a metal hemispherical shell and a separate bearing liner that can be made of a number of different materials. On the ball side of the joint (the femoral component) usually a stem is implanted into the central cavity of the upper femur and a ball is impacted onto the end of this stem. The ball itself can also be made of different materials and come in different sizes, allowing a “best” match or fit for each individual. Resurfacing Total Hip Replacement is a different type of THR, which involves insertion of a one-piece socket and a metal cap is placed over the ball. This technique has a limited place in the management of osteoarthritis.
THR components – acetabular (socket) and femoral stems – can be either cemented into place using an acrylic cement to anchor the component to the bone OR uncemented using a special surface on the component to get the bone of the socket or femur to grow onto the surface and lock them in place. Most acetabular components used nowadays are uncemented and rely on the coarse honeycomb like bone of the natural socket to grow into the gaps on a roughened or meshed surface on the back of the implant, effectively locking it in place. Sometimes in diseased or fragile bone using cement is better. The bone of the cavity or canal of the upper femur is much more solid, like a pipe – in this circumstance an uncemented femoral stem can be implanted tightly against this bone or an acrylic cement can be used to secure the implant. There are pros and cons to each approach.
THR components can be made of different materials – non-corrosive metal alloys for the socket shells and femoral stems and polyethylene (a specialized “plastic” known as UHMWPE), ceramic or polished metal for the bearing surfaces of the ball and socket liner. Again there are pros and cons as to the constituents of the bearing surfaces in particular. There are a number of different models of hip replacement – a bit like different models of cars. They all have significant similarities with slight design or “accessory” differences but generally there is no one brand or type of prosthesis that is superior. Your surgeon will generally decide which would be the best for each individual and if you have questions regarding these issues just ask your surgeon.
Once a decision has been made to proceed with THR surgery, it is important that both parties involved – the patient and the doctor – work together to achieve the best result possible. Probably the most important issue in this regard is having a realistic expectation about what the outcome can be after surgery. Unfortunately THR is not perfect technology and it can never give the recipient a “normal” hip.
As such THR is a compromise operation – a compromise between a very arthritic hip and a normal hip. Our hope as surgeons is that a replaced hip would be very much at the normal end of the scale but the result can vary a little from person to person. A reasonable expectation would be a significant improvement in pain control particularly and hopefully a commensurate improvement in ability to undertake activity. Improvements in hip motion are variable but THR will not restore full motion. Most individuals are able to walk good distances unaided but occasionally gait aids/sticks are required – often to assist with balance and safety. Recreational pursuits such as swimming, cycling, gentle gym and exercise classes and bowls or golf can be undertaken. It is not advisable to undertake high impact activity such as running or jumping/jarring sports as this has the potential to prematurely wear out the bearing surfaces of any hip replacement. It is difficult to predict how long a replacement will last before it wears out requiring further surgery. This clearly depends on a number of factors but our best guess at this stage is that most modern THRs will probably last somewhere between 15 and 20 years. Unfortunately some hips fail earlier than this time frame. Putting things bluntly – you may need another operation to re-do or revise your THR if …… it wears out before you wear out!
The surgery itself takes approximately 2 hours to perform. Anaesthesia is required and can be a general or a regional anaesthetic or a combination of these two types. The anaesthetist will come and see you before surgery to discuss the type of anaesthetic that will be the safest for you – again there are pluses and minuses to each anaesthetic. Your surgeon will see you before your anaesthetic to answer any questions and most importantly to mark the surgical side/site with an indelible marking pen.
THR can be performed by a number of different approaches – this dictates which tissues/muscles are opened on the way to accessing the hip joint. The approach undertaken dictates where the skin incision is performed. Different approaches to the hip joint include the posterior approach, lateral approaches and an anterior approach. Again each approach has advantages and disadvantages. Successful THR can be performed through any of these approaches. Should you have any questions regarding approach, talk to your surgeon. Once the selected implants have been inserted the wound is closed with stitches or surgical clips and a dressing is applied. One or two drain tubes are left in the wound to drain any blood that may collect in the area. A special pillow is usually placed under or between the legs and this retained for the first few days post operatively.
Most patients undergoing THR surgery will stay in hospital around 5 days and in some cases a further stay for rehab is advisable. Your surgeon, supervising physiotherapist and nursing staff will advise you in this regard and make any arrangements that are necessary. Generally the day after surgery is a quiet day but usually involves a regime of bed exercises, standing out of bed with the physio and undertaking some limited walking. A blood test to check blood/haemoglobin levels and an xray of the new hip is usually performed. The drains are usually removed at the start of the second day and proper walking and standing exercises are begun. Over the next few days a progressive mobilization program with crutches is instituted with the aim of achieving readiness for discharge home. You need to able to walk a reasonable distance, dress and shower and negotiate stairs safely before going home. You need to understand that there are safe and unsafe ways of undertaking bending and rising tasks – your physio will teach you the correct way to do things.
Once at home it is recommended that you sleep on your back with a simple pillow between your legs in the first 6 weeks. You will generally need to use crutches and wear some compression or anti-embolic stockings in the first 6 weeks. At 12-14 days post surgery an arrangement will be made for a nurse to visit to remove any skin stitches or clips. At home you need to continue the mobilization program started in hospital with walking and gentle strengthening exercises. Driving is generally not advised in the first 6 weeks. At the 6 week mark a post-operative appointment with your surgeon is made to check your progress, answer any questions and to view some up to date xrays. All being well you can come off crutches and increase activity as comfort and confidence will allow. Your surgeon will talk to you about some simple “hip precautions” to safe guard your hip against problems. Most individuals having hip replacement will take 6 – 12 months to properly get over the surgery and back into normal levels of activity again.
There are some risks associated with THR surgery, just as there are with any surgical procedures. These risks can be broken down into general risks (that exist with any reasonable sized operation) and specific risks that relate to Total Hip Replacement itself. The risks listed below are the most common issues but this list is by no means all inclusive – if you have any concerns about these or any other risks, talk to your surgeon before surgery.
General risks include:
(1) Anaesthesia – modern anaesthesia is very safe, but with whichever method of anaesthesia is undertaken, there are very small risks. If you concerns in this regard, please talk to your anaesthetist when he/she comes to see you before surgery.
(2) Medical complications – chest and urinary infections, blood pressure and cardiac/other issues can occur following any significant surgery.
(3) Infection – there is approximately a 1% chance you could develop a significant infection in your hip. Antibiotics given at the time of surgery and post-operatively reduce this risk but do NOT entirely negate it.
(4) Deep Vein Thrombosis – this is a clot that can occur in the deep veins of the leg, usually beginning in the calf. Again this risk is minimized by medication, anti clot stockings and early mobilization but none of these things guarantees prevention. If serious, the clot could travel to the lung and in very rare instances this can be fatal. If you have had a thrombosis in the past, you are at greater risk of this complication – let your surgeon know if this is the case.
(5) Blood Loss – THR surgery is associated with some blood loss and occasionally a blood transfusion is required.
(6) Nerve or Vessel Damage – there are large vessels and nerves that travel into the leg both in front of and behind the hip. Damage to these structures is rare but possible.
Specific risks include:
(7) Dislocation – the ball and socket arrangement of a hip replacement is not as stable as a natural hip and sometimes can dislocate. The risky period is the first 6-8 weeks and it is over this time that strict hip precautions are in place. You will be advised of dangerous positions for your hip whilst in hospital. Dislocation can occur after this period but usually relates awkward movements when attempting bending/reaching tasks particularly when the hip is in a very flexed position.
(8) Leg Length – sometimes, hip replacement will alter the length of the leg being operated on. The aim of THR surgery is to leave both legs the same length but sometimes this is not possible for various reasons. Most discrepancies in leg length are small and not noticeable. Very occasionally the discrepancy can be larger and if this is the case insoles or shoe raises for the affected leg may be required to feel balanced when walking or standing.
(9) Implant Wear and Loosening – the bearing surfaces of a hip replacement will slowly wear down over time. As stated previously, it is hoped that these surfaces will last 15 – 20 years and sometimes beyond. There is always a possibility that a hip replacement may wear out or loosen at any stage even early, requiring further surgery.
As stated above this list of risks and potential complications is not exhaustive and if you have any concerns, please raise these with your surgeon before proceeding with hip replacement surgery.
Despite these potential issues, the outcome following THR surgery is in most cases excellent with markedly improved pain and function. Unfortunately, as with any operative procedure there is no surgery that is 100% successful and a small percentage of individuals may continue to have some pain and limitation.
Preparation for THR Surgery
Once the decision has been made by patient and surgeon to proceed with Total Hip Replacement (THR), what should be done to prepare for this surgery?
Optimisation of Medical Conditions
Touching base with your GP is important. Your surgeon will have written to your GP informing him/her of impending THR surgery. Ensure your medical conditions (eg hypertension, asthma, diabetes) are controlled as best possible.
In some circumstances, your surgeon may recommend seeing a specialist physician for an evaluation of fitness for surgery and anaesthesia. This doctor can help in planning for management of diabetes and anti-clotting medications which are often interrupted at the time of surgery. They can also drop in each day whilst you are in hospital to make sure that your chronic medical conditions are adequately treated through the peri-operative period.
If you have any infections (dental, skin or other) – these need to be treated and controlled before surgery. Skin sores, ulcers or breaches in the skin particularly on the operative leg must be healed before proceeding with surgery.
Obesity is a significant issue which increases the risks associated with THR surgery and anaesthesia. There is increased risk of infection, blood loss, deep vein thrombosis and post operative chest infection. Obesity also reduces the longevity of any implant inserted through increased wear of bearing surfaces with activity. Weight reduction is an important pre THR strategy – seeing your GP and coming up with a dietary and light exercise plan is important. For those who are markedly overweight, sometimes undertaking bariatric/gastric reduction surgery is important before proceeding to THR.
Smoking is also a significant health issue that can impact on the risks of surgery and anaesthesia. Cessation of smoking before surgery is vital and giving up for good as part of your preTHR workup will help your recovery and general health long term.
Blood thinning medications will need to be stopped prior to THR. Common examples are Warfarin/Coumadin, Clopidogrel or Plavix/Iscover. Often these medications have been prescribed to treat heart conditions or to reduce the risk of stroke. Your surgeon will often contact the prescribing doctor or arrange for you to see a physician to work out a plan to safely stop these medications and when to restart them if required. Anti-inflammatories and aspirin also have blood thinning properties and these need to be stopped 7 – 10 days before surgery. If you have any concerns about any medication you are taking and whether you need to stop/alter this, please contact your surgeon for clarification.
Pre-operative tests are mandatory before THR surgery. You will need blood taken in the week before surgery. This is to determine haemoglobin, white cell and platelet levels, electrolyte levels and renal function and to undertake a blood grouping and cross match, so that blood is available if required. An ECG is performed to check for basic heart abnormalities. A urine test is performed to ensure no infection is present. If you haven’t had a recent hip xray (in the last 6 months), then this may be undertaken as well. Occasionally other tests – chest xrays, clotting profiles etc may be required.
Generally those who are fitter before surgery will recover faster. Unfortunately hip arthritis generally leads to deconditioning, which can be difficult to address pre-operatively. Touching base with a physiotherapist who can offer a “Prehab Program” can be really helpful and give insights as to the types of exercise/techniques required to get moving after surgery.
This usually takes place a week or two before surgery at the hospital concerned. You will meet nursing staff and sometimes ward physios who will explain what will happen in hospital – before and after surgery. They will also organize for equipment – a toilet seat raise, a higher sitting chair with arms, a pick-up stick and sometimes walking frames and crutches – to be supplied. It is important that you attend this session.
By the time you arrive home after THR surgery you should be able to walk a reasonable distance with crutches or a suitable walking aid and be able to shower/toilet and dress independently. You made need assistance with cooking, shopping and household chores – planning ahead for these events is important. Having a chair where you can sit comfortably with your knees below the level of your hips is essential. Arms on this chair will assist with rising from a seated position. Handrails in the bathroom can be helpful as can a long handled shoe –horn and sock aid. You should be supplied with a pick up stick that will allow you to grab objects without excessive bending of your new hip. Removing rugs and loose electrical cords from areas where you walk can prevent an unwanted fall. Setting up a “recovery centre” near a favourite chair where you may spend a significant amount of time each day is sensible – having things like the phone, TV remote, reading material and medications/drink (preferable non-alcoholic) within easy reach.
Planning ahead and preparation for THR surgery can make recovery faster and easier, minimize the potential for post-operative complication and provide a healthy and safe platform for a return to normal life activities.