Disorders of the inert structures

Published on 10/03/2015 by admin

Filed under Orthopaedics

Last modified 22/04/2025

Print this page

This article have been viewed 2593 times

Disorders of the inert structures

Chapter contents

Capsular pattern

The capsular pattern at the hip joint is gross limitation of medial rotation, abduction and flexion, less limitation of extension, and little or no limitation of adduction and lateral rotation (Fig. 47.1). In advanced arthritis, abduction and internal rotation are impossible and associated with obvious limitation of flexion and extension.

Fig 47.1 The capsular pattern at the hip joint.

A capsular pattern in the hip joint of a child or adolescent always implies a serious problem. The slightest limitation of movement should be reason enough to put the child on bed rest and start diagnostic procedures to detect the cause. Weight bearing is prohibited until the reason for the capsulitis is discovered (see online chapter Hip disorders in children).

If a capsular pattern is present at the hip and resisted movements do not hurt, the conditions discussed in this section should be considered.

Monoarticular arthritis in middle-aged people

This condition was described by Cyriax ⁵ (his p. 386). For no special reason, a middle-aged patient experiences aching at the anterior aspect of the thigh during exertion. Clinical examination of the hip shows only a slight capsular pattern, with some limitation of internal rotation and flexion. There is pain at the end of range and the end-feel is elastic. The radiograph reveals nothing but a normal hip joint. The condition continues unchanged for months. Intra-articular injection with triamcinolone seems to be ineffective, but the lesion responds very well to stretching of the capsule, which relieves the pain quickly and permanently (see p. 633–634 for technique).

Osteoarthrosis

Aetiology

It is widely accepted that the most likely causative factor in the development of arthrosis of the hip is the incapacity of (parts of) the hip to withstand mechanical stresses. In the literature, a distinction is made between primary and secondary arthrosis.⁶

Secondary arthrosis originates from a pre-existing anomaly at the hip, such as Perthes’ disease, acetabular dysplasia and epiphysial dysplasia. Rapidly developing osteoarthrosis most often results from aseptic necrosis.

When the osteoarthrosis results from an undetermined abnormality of the cartilage or the subchondral bone, the condition is called idiopathic or primary. Primary osteoarthrosis is extremely rare – in more than 90% of cases, previous abnormalities in the hip joint can be demonstrated.7–9

Initiation and progression of osteoarthrosis at the hip seem to be caused by continuous interaction between such factors as deterioration of articular cartilage, changes in the subchondral bone, stiffening of the capsule, dysfunction in the neuromuscular system and chemical changes in the composition of the synovial fluid.

Cartilage fibrillation

Articular cartilage is a viscoelastic substance. It deforms slightly under load. The main purposes of the tissue are (a) to transmit joint forces to underlying bone structures, (b) to minimize the frictional drag of joint motion and (c) to maximize the contact area of the joint under load.

Strain may induce loss of proteoglycan molecules in the collagen network.¹⁰ This results in an increase in hydration and loss of tensile strength, and initiates the fibrillation of the cartilage.^11,12

Subchondral bone

The health of articular cartilage depends largely on the mechanical qualities of its bony subchondral bed: the greater the discontinuity in elasticity between cartilage and subchondral bone, the more shear stress will occur.¹³ The presence of stiffened subchondral bone thus increases the likelihood of the progression of cartilage lesions.¹⁴

Capsule of the joint

Inflammation of the synovial membrane can also be responsible for the degeneration of cartilage: connective tissue activating peptides and catabolites are set free during inflammatory reactions and have a negative influence on cartilage and subchondral bone.15,16

In addition, rigidity of the capsule, so often seen in the early stages of arthrosis,¹⁷ plays a role in its progression: because of the loss of laxity, the normal gliding movement of the cartilage surfaces is altered, which imposes a change in load distribution and thus increases stresses on particular areas of the joint.

Synovial fluid

The composition of the synovial fluid may enhance the development of osteoarthrosis: a decrease in viscoelastic quality provokes more friction between the joint surface. It is well to remember that immobilization also decreases synovial fluid hyaluronan levels and may thus contribute to the progression of osteoarthrosis.¹⁸

Muscular dysfunction

Muscular dysfunction and disturbed neuromuscular balance are quite common in osteoarthrosis of the hip. They cause the joint to work under abnormal conditions and may play a role in the development or continuation of hip osteoarthrosis.¹⁹ A pattern of tightness and overactivity of the psoas, adductors, tensor fasciae latae and rectus femoris is typical in arthrosis of the hip joint, whereas the gluteals show a tendency towards weakness and inhibition.^20,21

The continuous interaction between the changing structures of the joint imposes a physiological imbalance, which starts the process of degeneration. Vigorous and persistent attempts to repair the degenerative changes aggravate the already disordered joint function and set up a vicious circle. Hypervascularity, weakening of the subchondral bone, fatigue fractures, localized zones of collapse, flattening of the femoral head and formation of osteophytes then become inevitable (Fig. 47.3). This whole process can lead to rapid destruction of the joint; however, this is not always the case and spontaneous clinical and radiological improvements can occur.²²

Fig 47.3 The aetiology of osteoarthrosis.

Conclusion: osteoarthrosis is a ‘joint failure’, similar to ‘heart failure’. The aetiology is multiple but each of the components of the joint (cartilage, subchondral bone, synovial fluid and joint capsule) plays a role in the pathogenesis.

Symptoms and signs

Although the diagnosis of advanced arthrosis of the hip is easy, it may be difficult to diagnose the early stages. Also, there is sometimes a striking lack of correspondence between the clinical picture and the radiographic appearance.

Symptoms

The pain is located in part of the L3 dermatome: the groin, the anterior aspect of the thigh, the knee and the leg as far as the ankle joint. It is important not to forget that a separate part of the dermatome is located in the region of the sacroiliac joint, so patients with arthrosis of the hip may also present with unilateral pain in the lower back.

In the early stage, pain is only present during and after exercise but later it becomes continuous and can even disturb sleep. It is suggested that pain at night in coxarthrosis is associated with an increase in intracapsular pressure and subsequent joint contracture.²³ If the patient mentions twinges during normal walking, the disorder is considered to be complicated by impacted loose bodies (see later).

Signs

The examination often reveals a capsular pattern, with internal rotation the most limited and some limitation of flexion, extension and abduction, but this is certainly not always so. Many cases of hip osteoarthrosis present with other movement restriction patterns: for example, gross limitation of both internal and external rotation.²⁴ As a rule, there is considerable difference between the clinical signs of an early osteoarthrosis and those found in advanced cases.

In the early stage, there is merely a capsular stiffening, without much erosion of cartilage or osteophyte formation. The clinical findings are therefore a capsular pattern with a less elastic end-feel. Most commonly, internal rotation is found to be the most painful and limited, followed by limitation of flexion, abduction and extension.

In advanced instances, gross limitation is found, with loss of all rotational movement. In extreme cases, a ‘hinge joint’ develops, allowing only flexion and extension in an oblique plane: the femur moves laterally when flexion is forced. The end-feel is hard and marked coarse crepitus can be palpated. Muscle tightness can sometimes be detected by performing muscle length test procedures such as those described by Janda and Lewit.25–27

Radiography

‘Osteoarthrosis of the hip’ must be a clinical diagnosis and it is unwise to rely entirely on the radiograph for estimation of functional incapacity and for deciding on optimal treatment. First, there is a considerable lack of correspondence between the degree of pain, the mobility of the joint and the radiograph appearances.²⁸ Second, the patient may suffer from other lesions at or around the arthrotic hip. These lesions – loose body, psoas or gluteal bursitis (see pp. 642–647) – are not radiographically visible. If a radiological examination is performed without a full history and proper clinical examination of the hip, such conditions will be missed and the painless arthrosis will be blamed for the pain.

The radiological changes in hip osteoarthrosis are: presence of subchondral sclerosis in femoral head and acetabulum, joint space narrowing, femoral head deformity, marginal osteophytes, cystic changes in the femoral head and the acetabulum, and migration of the femoral head. The severity of the radiological changes is classified into four grades (Kellgren 1–4). Classically, there are three radiographic types of arthrosis of the hip, according to the direction of migration of the femoral head.

• Most osteoarthrotic hips show superolateral migration of the femoral head with localized erosion of cartilage at the lateral border of the labrum and a widening of the inferomedial part of the joint.²⁹ Cameron and MacNab suggest that this is the form of osteoarthrosis that is primarily related to capsular restrictions and responds well to capsular stretching.³⁰

• A medial–axial migration occurs in about 10–15% of cases. This presentation is usually associated with gross osteophytosis at the lower border of the femur and labrum.

• Another 10–15% of cases are non-migratory hip osteoarthrosis, associated with superior or concentric loss of cartilage space and concentric formation of osteophytes (Fig. 47.4).

Fig 47.4 Migration of the femoral head: (a) superolateral migration; (b) non-migratory hip osteoarthrosis; (c) medial–axial migration.

Treatment

Early treatment of osteoarthrosis is vital. There is evidence that reduced motion of the hip (from capsular tightening and muscular imbalance) further increases the degenerative process in cartilage and subchondral bone. Several studies have demonstrated the beneficial effect of exercise on pain and disability.³¹ The treatment of choice is therefore early stretching of the joint (grade B mobilizations). Treatment with injections has only a limited indication. In later stages or in quickly developing osteoarthrosis, conservative treatment is useless and surgery is indicated (Box 47.1).

Box 47.1 Treatment of osteoarthrosis of the hip

Early and/or slowly developing osteoarthrosis

Capsular pattern, ligamentous end-feel and absence of coarse crepitus

• Capsular stretching – angular mobilizations

• In flexion

• In extension

• In medial rotation

• Traction (manual or mechanical)

• In maximally loose-packed positions

• In other positions

• Muscular re-education

• Stretching of shortened muscles

• Activation of inhibited muscles

• Gait control

• (Intra-articular injections)

Advanced and/or quickly developing osteoarthrosis

Non-capsular pattern, hard end-feel and coarse crepitus

• Surgery

• (Intra-articular injections may give temporary relief)

Capsular stretching

It is generally believed that early stretching of a tight capsule may prevent joint damage or at least slow further progression.³² Therefore, stretching is the treatment of choice in the early stage of the disease. The decision to use it depends largely on the clinical findings: early arthrosis with a slight capsular end-feel usually responds quite well to such treatment. Stretching is of no use in advanced arthrosis with gross limitation of movement, a hard end-feel and coarse crepitus because these are the clinical indications of gross cartilaginous destruction and formation of large osteophytes.

It is vital to start stretching treatment as early as possible. A stiff and inflamed capsule is one of the reasons for disturbed load distribution, responsible for further progression of degeneration. Furthermore, overuse at a stiffened capsule provokes consecutive strains, resulting in traumatic inflammation and pain.

Treatment is given 2–3 times a week, for 10–20 sessions. The joint is mobilized in three directions – flexion, extension and internal rotation – for 5–10 minutes each. The patient may experience slight aching for 1 or 2 hours after the forcing. This is an important criterion to the therapist, who must adjust the vigour of the treatment according to the length of time that the increased pain lasts. Slight after-pain for 1–2 hours is acceptable. If the patient suffers from increasing pain over 1 or 2 days, it is clear that the joint has been forced too much. If neither after-pain nor improvement follows, greater stress, more persistently applied, is used during the next visit.

The result that can be expected is not a marked increase in range but merely a decrease in pain. It is remarkable that pain at night, even of many months’ standing, can often be abolished by a few sessions of capsular stretching. Used at an early stage, years of relief can often be obtained, although it may be necessary to repeat the mobilizations once or twice a year to keep the capsule as mobile as possible.

Technique: forced flexion

The patient adopts a half-lying position on the couch. The therapist stands on the affected side, level with the patient’s knee. The hip is flexed as far as is comfortably possible. One hand rests on the anterior aspect of the knee, while the other presses the opposite thigh down towards the couch. With steadily increasing pressure applied to the knee, the thigh is forced towards flexion (Fig. 47.5). This position is maintained for as long as the patient can bear it: e.g. 1 minute. The pressure is then slowly released to give the patient a break and the same procedure is repeated.

Fig 47.5 Forced flexion of the right hip.

Technique: forced extension – 1

The patient lies prone on a high couch. The therapist stands level with the thighs. To prevent stress on the lumbar spine, it is vital to keep the patient’s pelvis on the couch when extension of the hip is forced. Therefore, with one hand, the therapist presses on the lower part of the buttock, which will obstruct movements at the lower back and the sacroiliac joint. With the other hand, the therapist grasps the thigh from the medial side, just above the patella. Both arms are kept rigid. Bending the body sideways, the therapist then pulls the patient’s thigh upwards, while the patient’s pelvis is pushed forcefully downwards (Fig. 47.6).

Fig 47.6 Forced extension of the right hip – 1.

Technique: forced extension – 2

Some elderly people have difficulty lying on their stomach for any length of time and an alternative method can be used. The patient lies flat on the back, with the head supported with a cushion. The painless hip is now forced as far into flexion as possible, which tilts the pelvis and makes the other thigh lift off the couch. Sufficient extension can now be forced when sustained downward pressure is applied just above the patella (Fig. 47.7).

Fig 47.7 Forced extension of the right hip – 2.

Technique: forced medial rotation

The patient adopts a prone-lying position on a high couch. The knee at the affected side is bent at a right angle. The therapist stands on the affected side and level with the pelvis. The ipsilateral hand is pressed on to the ilium. The other hand is placed at the medial malleolus and forces the hip into medial rotation. The pelvis rotates and moves the iliac crest backwards on the opposite side. Pressure applied on the pelvic region now forces the iliac crest downwards again. When the thigh on the affected side is held firmly in the rotated position, this downward pressure will considerably increase the outward stress on the affected hip (Fig. 47.8).

Fig 47.8 Forced medial rotation of the right hip.

Traction

Traction (either manual or mechanical) is an alternative technique to stretch the joint capsule.33–35

Practitioner’s checklist

• The ratio of pain to end-feel will indicate the degree of applied force (see general principles of treatment, p. 93). Movements should be performed to the point of discomfort but not of pain. In suitable cases, the force can be gradually increased during the session. A whole session takes about 20–30 minutes, with pauses after every 30 seconds–1 minute.

• Slight passive oscillatory movements can be added: type I and II mechanoreceptors come into play and suppress a painful reaction from the nociceptors (see p. 92). To prevent adaptation of the mechanoreceptors, oscillations should be constantly changed in rhythm, amplitude and direction.

• Although osteoarthrosis and osteoporosis do not seem to appear simultaneously, the former protecting from the latter and vice versa,36,37 forcing medial rotation should always be carried out with caution in elderly people, for fear of fracturing the neck of the femur.

Manual traction (distraction) can be given in two different ways: with an extended knee, in which case the traction is performed via the ankle; or with the leg flexed to more than 90°. Traction is then carried out via the proximal part of the upper leg. Because of the direction of the hemispherical acetabulum, in either case the femoral head moves inferiorly, anteriorly and laterally. Depending on the position of the joint, some parts of the capsule are stretched more intensively.

Traction I

The patient lies supine near the edge of the couch. To prevent the pelvis being pulled down or sideways, or lifted off the couch, two bands are used for fixation: one at the groin, and the other transverse over the pelvis just beneath the anterior superior iliac spines.

The therapist grasps the patient’s ankle. According to the direction of the acetabulum – inferiorly, laterally and anteriorly and in agreement with the maximally loose-packed position of the joint capsule – the leg should be brought into a position of about 30° of flexion, 30° of abduction and slight lateral rotation.

Traction is performed by leaning backwards with straight arms (Fig. 47.9). Once the therapist feels the patient relaxing the muscles, a jerk can be tried by pulling the arms towards the body. At this point, slight separation of the femoral head from the acetabulum can be felt.

Fig 47.9 Manual traction.

Traction II

The therapist sits or stands at the level of the pelvis. The leg should be flexed to at least 90° and slightly laterally rotated. Both hands take hold of the upper part of leg (Fig. 47.10a). Traction is performed in the direction of the acetabulum: inferiorly, laterally and anteriorly.

Fig 47.10 Mechanical traction.

Use of a band makes it possible to lessen the effort of the therapist a great deal. Both hands then hold the leg in position at the knee (Fig. 47.10b). Traction is achieved by leaning backwards.

Traction II is not suitable for manipulating the joint.

It must be noted that distraction of the hip joint can only be effective if the pelvis is completely immobilized; otherwise, the lumbar spine will compensate for the movement. To this end, two fixation belts are used. One should resist the movement of the pelvis caudally, while the other resists anterior and lateral displacement.

Muscular re-education

In order to correct the pattern of muscular dysfunction and a disturbed neuromuscular balance, selective activation of inhibited, weak muscles and stretching of tight, shortened muscles is advocated by several authors.38–41 The second measure is of even greater importance because tight, hyperactive muscles interfere with the activation of inhibited muscles. These muscles (usually psoas, tensor fasciae latae and rectus femoris) are stretched slowly without straining the joint.

Activation of inhibited muscles is achieved by exercises with low loads to prevent overflow into other muscles. It is also advisable to perform exercises as closely as possible to their functional manner. For this purpose, closed kinetic chain exercises are advocated because the weight-bearing component effectively stimulates mechanoreceptors around the joint, so improving muscular contractions.⁴²

Hip extensors can be activated lying supine, the lower leg over the edge of the couch, the hip extended and the knee in 90° of flexion. Pushing the foot on the floor facilitates both the gluteus maximus and the posterior part of the gluteus medius.

Activation of the hip abductors is performed first sitting near to the edge and at the corner of the couch, one leg extended and in contact with the floor. Supporting him- or herself on this leg, the patient activates the hip abductors. Standing with the feet about 25 cm apart and resisting pressure against the pelvis from the contralateral side is another effective exercise to activate the ipsilateral hip abductors. This can also be achieved if the patient is asked to lower and raise the contralateral pelvis. Placing the hands on a chair at each side of the body for support reduces the load.

In order to reduce the harmful effect of a limp, a walking stick in the contralateral hand may be necessary at first. It decreases the contraction of the ipsilateral hip abductors and thereby reduces compressive forces on the joint.

Finally, it is necessary to be aware of any harmful effect produced by the trunk or lower limb that might influence the development and continuation of the hip joint problems, i.e. stiffness of the lumbar spine, leg-length differences, or dysfunction at the knee or the talocrural or subtalar joint.

Intra-articular injections

If the patient suffers from a subacute exacerbation because of traumatic arthritis superimposed on a stiffened arthrotic capsule, one intra-articular injection with 50 mg of triamcinolone will relieve the traumatic inflammation and the pain but increased mobility will not follow. To avoid arthropathy, this injection should not be repeated.⁴³

Also, intra-articular injections with hyaluronic acid seem to be a safe and effective method of treatment for patients with advanced hip arthrosis and may lead to a significant reduction in pain scores, disability scores and analgesic use.44–46

Surgery

A McMurray intertrochanteric osteotomy is indicated in a painful hip that has good mobility. It has the advantage of diminishing pain while maintaining a useful range of motion in the ‘natural hip’.

Total hip replacement is indicated in advanced osteoarthrosis. It is one of the most commonly performed operations in the United States, with over 280 000 procedures reported annually.⁴⁷ The benefits of total hip replacement in terms of reduced pain and improved function and quality of life for patients with advanced coxarthrosis have been well documented in the literature.⁴⁸ The prosthesis is made up of two parts: an acetabular component made of a metal shell with a plastic inner socket (the socket portion) that replaces the acetabulum, and a femoral component made of metal (the stem portion) that replaces the femoral head.

There are two major types of artificial hip replacement: cemented and uncemented. Cemented total hip replacement uses cement to secure an implant to the bone, while with cementless technology the bone heals directly to the prosthesis. The choice is usually made based on age, body weight and lifestyle. Patients with poor bone quality or with less active lifestyles are candidates for cemented total hip replacement.

The life expectancy of the prosthesis is between 15 and 20 years.⁴⁹ Aseptic loosening with or without osteolysis is the major problem and accounts for 71% of the revisions, but the incidence had decreased three times during the past 15 years to less than 3% at 10 years in Sweden.⁵⁰ However, long-term durability of the acetabular components remains a major concern.⁵¹

Concerns regarding high rates of failure among young, active patients and a desire to preserve bone for future revision operations led to the development of hip resurfacing arthroplasty. This differs from total hip replacement in that the femoral head is resurfaced rather than resected, thereby preserving femoral bone stock, which could theoretically decrease morbidity and improve patient outcomes associated with future revision operations.52,53

Non-capsular pattern

A non-capsular pattern on clinical examination of the hip indicates the possibility of lesions of the joint itself or disorders of nearby tissues such as the buttock and the groin. The straight leg raising test and resisted movements help to differentiate the two possibilities.

Serious lesions in the buttock are characterized by an interesting pattern of physical signs, called the ‘buttock sign’, summarized in Box 47.2. Non-capsular lesions of the hip itself comprise loose bodies, bursitis and aseptic necrosis of the femoral head.

Disorders with a positive ‘buttock sign’

This clinical syndrome, described by Cyriax ⁵ (his p. 375), always indicates a major lesion in the buttock.

The buttock sign is characterized by more limitation and/or pain on passive hip flexion with a flexed knee than with an extended knee (i.e. straight leg raising; Fig. 47.11). The other passive movements at the hip joint are limited in a non-capsular way. This strange pattern immediately draws attention to the gluteal region. If the hip joint itself were affected, straight leg raising would not be limited, except in those gross articular patterns in which flexion cannot reach 90°. If the nerve roots, the sciatic nerve or the hamstrings were affected, hip flexion with a flexed knee would not be painful or limited because it does not stretch these structures. The fact that both movements are limited and painful implicates other structures in the gluteal region.

Fig 47.11 The buttock sign: passive hip flexion is more limited and/or painful than straight leg raising.

Checking for the buttock sign is very important in pain syndromes at the gluteal region. Because there will probably be nothing characteristic about the pain, only a comparison between the results of the straight leg raising test and passive hip flexion can detect serious disorders in the buttock.54–56 When this typical combination of signs emerges, a very careful examination of passive and resisted movements must follow. Passive movements disclose a non-capsular pattern, almost always with a full range of medial rotation. The end-feel of the limited movements is ‘empty’: as a consequence of the increasing pain, the examiner has to stop the movement, even though it is felt that the end of range has not been reached. Some resisted movements are painful and weak as well because they increase the tension on the affected tissues. As a rule, resisted extension and internal rotation are the most painful. Palpation may disclose a painful swelling.

To refine the diagnosis, the general temperature must be noted, a rectal examination performed and radiographs and/or bone scans done.

Septic bursitis

This is by far the commonest cause of a positive ‘buttock sign’. The condition usually occurs after direct inoculation during an intramuscular injection, although haematogenous dissemination is also possible, especially in the elderly.

History

The history is often rather trivial, with increasing gluteal pain spreading down the back of the thigh to the knee and calf. During the first few hours or days, the pain eases at rest and increases during movement. Coughing does not hurt. The features do not draw immediate attention to the buttock but rather suggest a nuclear disc lesion.

Clinical examination

The patient’s gait is hobbling, as if the weight can hardly be borne on the affected leg.⁵⁷ This major disability contrasts markedly with the minor degree of discomfort and is the first warning for the examiner.

Examination of the lumbar spine shows limitation of flexion, sometimes with a list towards the pain. This is logical since the pain increases when tension on the affected tissues increases during forward flexion of the spine. The other lumbar movements are of full range and painless, while straight leg raising is painful and somewhat limited.

These clinical examination findings correspond perfectly with the classic findings of a disc protrusion, so the diagnosis will be missed if the examination is not properly performed. When passive flexion at the hip joint is tested, the buttock sign will be apparent at once.

The local temperature is raised and palpation reveals a tender area just above and behind the greater trochanter. In advanced cases, an abscess may have formed, revealed by a swollen, tense and fluctuating area in the buttock.

Treatment

Treatment consists of ice packs, bed rest and antibiotic therapy. If there is an abscess, the lesion must be drained.

Sometimes the buttock sign and the localized and fluctuating swelling result from an acute haemorrhage after trauma: for example, a fall on the buttocks. Here the history of trauma is informative and the temperature is normal. Aspiration usually leads to complete cure.

Ischiorectal abscess

Occasionally, an anorectal abscess points towards the ischiorectal fossa instead of to the rectal region – an ischiorectal abscess.⁵⁸

Usually, the patient complains of gluteal pain, rather than of local rectal pain, and nothing in the history suggests an infection of rectal origin; the pain is related to movement and posture and not to function of the bowel.

Sitting is impossible. The patient limps badly and even putting the foot to the ground causes considerable pain.⁵⁹ The hip is held constantly in slight flexion but further flexion is prevented by increasing pain, as is straight leg raising, indicating the buttock sign. Apart from fever, other toxic symptoms may be present. The abscess may be felt during bidigital rectal examination with the index finger in the rectum and the thumb external.

The treatment is surgical and consists of prompt incision and adequate drainage.⁶⁰

Fractured sacrum

Sacral fractures are associated with pain, swelling, ecchymosis and tenderness on palpation. In the presence of neurological symptoms, the diagnosis is usually not difficult. Neurological damage is not present, however, if the fracture line lies through the ala. Because of the position of the sacroiliac ligaments, the fracture remains stable and the diagnosis is then frequently missed.⁶¹ The patient may ascribe discomfort to local bruising and sometimes continues to be mobile.

In a spontaneous sacral insufficiency fracture in an elderly woman the diagnosis is more difficult.62,63

There is pain during walking and standing but also local tenderness during sitting or lying. Coughing and sneezing also hurt. Careful clinical examination discloses the buttock sign. Sacroiliac tests are very painful. During digital rectal palpation of the sacrum, the anterior part is found to be as painful as the posterior, a strong sign of sacral fracture.

Because the sacrum is curved, diagnosis on a radiograph is not always easy. It is therefore advisable to obtain anteroposterior and lateral tomograms.⁶⁴

If the fracture is markedly displaced or associated with neurological deficit, surgical reduction and stabilization must be performed. In uncomplicated fractures, treatment consists of aspiration of the haematoma and rest for 4–6 weeks, although bony union without deformity seems to take place whether the patient rests or not.⁶⁵

Neoplasm at the upper femur

Metastases or primary tumours in the upper femur give rise to increasing pain in buttock and thigh. After a short development of the disease process, the functional disability may be so gross that it prevents the patient bearing weight on the affected side. There is also pain at rest.⁶⁶

Examination reveals the buttock sign. If the lesion lies in the neighbourhood of the lesser trochanter, resisted hip flexion is painful and weak. Marked wasting of the thigh muscles is present in advanced cases. The diagnosis is confirmed by radiography.

Neoplasm in the ilium

Again, the patient complains of increasing gluteal pain, not only during movement (the patient can only hobble with assistance) but also at rest. The buttock sign is present but the other passive movements are of full range and almost painless. Some resisted movements are painful and weak, and marked muscular atrophy is seen. The contrast between the extreme pain and the almost full range of passive movement, in combination with the buttock sign, makes the diagnosis obvious. The radiograph confirms it.

Osteomyelitis of the upper femur

Osteomyelitis is suspected when local symptoms and signs are accompanied by high fever and toxic manifestations. Sometimes, however, the patient is afebrile, and then only complains of local symptoms – increasing and continuous pain in the buttock and thigh. This contrasts with the signs: hobbling with a bad limp, suggesting gross arthritis, but further clinical examination reveals a non-capsular pattern at the hip joint together with a clear sign of the buttock. Early in the evolution it is possible for the radiograph to be negative. If there is any doubt, a bone scan should be obtained.

Septic sacroiliac arthritis

This disease affects young patients. Predisposing factors are immunosuppression, drug addiction and childbirth.67,68 In addition to demonstrating the positive buttock sign, the sacroiliac distraction test is extremely painful. Fever and general illness are present,⁶⁹ together with local tenderness over the joint.

Radiological examination remains negative ⁷⁰ in the early stage but computed tomography (CT) or bone scan usually confirms the diagnosis.⁷¹

Loose femoral prosthesis

A sign of the buttock in a patient who underwent a hip arthroplasty in the past may indicate a loose femoral prosthesis. Radiological diagnosis may be difficult and obscured by artefacts.⁷²

Aseptic necrosis of the hip

Aseptic necrosis (osteonecrosis, ischaemic necrosis and avascular necrosis are synonymous) of the hip is an osteoarticular disorder characterized by bone marrow ischaemia and death of trabecular bone of the femoral head. As bone repair occurs, weight-bearing bone becomes mechanically weakened and flattened and may eventually collapse. Secondarily, this leads to quickly developing osteoarthritis of the hip. In children it is called Perthes’ disease (see online chapter Hip disorders in children).

Aseptic necrosis of the hip in adults was first described in the German literature.⁷³ Two types – post-traumatic (complicating fractures or dislocations) and idiopathic – exist. The latter has been the subject of many experimental and clinical studies over recent decades. All observations show an increasing incidence,⁷⁴ although this is probably due to improved diagnostic techniques. The fact that the disease is not uncommon was shown by Streda in 1971,⁷⁵ who found that 68% of patients with current osteoarthritis had pre-existent osteonecrosis.

Pathogenesis

It has been accepted for years that non-traumatic osteonecrosis of the hip results from progressive ischaemia, caused by interruption of the arterial supply of the femoral head.⁷⁶ Experimental and clinical studies, however, indicate that other mechanisms can induce bone necrosis. The fact that aseptic necrosis occurs most frequently in patients treated with high-dose corticosteroids⁷⁷ and in those with a history of alcohol abuse⁷⁸ suggests a direct toxic effect on the osteocytes.⁷⁹ This results in local inflammatory exudate and increased intraosseous bone marrow pressure. Elevation of intraosseous pressure is transmitted to small venules and capillaries within the bone, causing a decrease in blood flow to the bone. This uncompensated increase in intraosseous pressure is thought to result in irreversible circulatory disturbances and subsequent tissue damage, which further magnifies the initial result.⁸⁰ The problem with osteonecrosis is that the radiological evidence only appears months after the process has started: necrosis of bone is only the irreversible end result of severe and prolonged ischaemia. Furthermore, it is not the necrosis itself but the reaction of the tissue to the ischaemia that shows up on a radiograph. For these reasons, a standard radiograph cannot assist in early diagnosis. However, diagnosis and treatment at an early stage are extremely important if gross damage to the femoral head is to be avoided.

Diagnosis

Early diagnosis of aseptic necrosis is important because the disease occurs in relatively young individuals (average age 20–50 for idiopathic forms) and treatment options for more advanced disease are frequently unsuccessful.

Any sudden and progressive groin pain – eventually spreading down the L3 dermatome – in a patient under the age of 50 should immediately arouse suspicion of the onset of aseptic necrosis, especially if there is a clear discrepancy between marked symptoms (pain) and nearly absent signs (full range of movement in the hip).

The classic radiological techniques (plain radiographs and a CT scan) are inefficient in making an early diagnosis and other methods of investigation should be used.

Bone scan

A bone scan usually shows increased uptake of the radionuclide from the very beginning of the disease – the sensitivity is about 70%.⁸¹ Both sides should be compared.

Magnetic resonance imaging (MRI)

Nowadays, MRI is the most sensitive non-invasive method for the diagnosis of aseptic necrosis, which is diagnosed when a peripheral band of low signal intensity is present on all imaging sequences, typically in the superior portion of the femoral head, outlining a central area of marrow. This peripheral band is most apparent on T1-weighted sequences.82–85 Because the two hips are frequently involved, it is necessary to image both, not just the symptomatic one. The sensitivity of MRI is between 75 and 100%.

Staging

There are two staging classifications of aseptic necrosis, one based on radiographs (Table 47.1) (Ficat and Arlet⁸⁶) and the other on MRI signal intensities⁸⁷ (Table 47.2).

Table 47.1

Stages of bone necrosis of the femoral head, adapted from RP Ficat ⁸⁸

Table 47.2

MRI staging of aseptic necrosis ⁸⁷

The staging of Ficat and Arlet is based on clinical features, radiographic signs and scintigraphy. The accuracy of radiographic staging may be improved by using CT to detect subchondral lucency. However, CT does not depict the earliest marrow abnormalities.

Stage 0

This is a theoretical, preclinical and preradiological stage.

Stage I

The earliest clinical manifestations are sudden groin pain (sometimes referred to the L3 dermatome), often pain at night, and increasing pain on weight bearing.⁸⁹ Coughing may hurt.

Clinical examination normally shows a full range of movement. Sometimes there is pain in a non-capsular pattern: external rotation and flexion hurt at the end of range.⁹⁰ This could suggest the presence of a psoas bursa or an impacted loose body. Sometimes a forceful axial and upward blow on the heel also provokes groin pain.

Standard anteroposterior and lateral radiographs are entirely normal but a bone scan shows increased uptake of the radionuclide.⁹¹ The MRI is positive.

Stage II

This early radiographic stage can continue for several months. The clinical symptoms and signs persist or increase. Radiographic changes, although very subtle, appear: slight diffuse sclerosis and slight decalcification, either generalized or in the form of small cysts. Again, the bone scan shows increased uptake and the MRI is positive.

Stage III

There is increasing L3 pain. The patient limps or enters the room leaning on a stick. The clinical examination shows a slight capsular pattern, and forceful axial thrust on the heel provokes the pain.

This stage is characterized by pathognomonic radiographic appearances:

• A ‘crescent line’, due to a subchondral fracture and a segmental flattening of the femoral head.

• Later, a sequestrum becomes manifest, followed by collapse of the femoral head.

Stage IV

This is the terminal phase of the necrotic process. There is clinical evidence of gross arthrosis. The radiographic picture is that of an arthrosis, superimposed on a deformed femoral head.

MRI staging of aseptic necrosis is based on the signal intensity of the centre of the marrow inside the dark line of necrosis.⁸⁷ Radiographically occult aseptic necrosis will generally be depicted on MRI as any of classes A–C. Unlike radiographic staging, MRI classes have little predictive value regarding the prognosis for collapse of the femoral head. However, MRI size and position of the necrotic lesion are related to prognosis.

Treatment

The most important factor in effective treatment of non-traumatic osteonecrosis of the hip remains early diagnosis.⁹²

While patients with advanced aseptic necrosis usually end up having hip arthroplasty, some of those whose lesion has been diagnosed early (at pre-collapse stage) have been managed with hip salvage surgery.⁹³ A variety of drugs have also been used, such as lipid-lowering drugs, anticoagulants, vasodilators and bisphosphonates.^94–96 Their use has been considered on the basis of specific physiological risk factors for osteonecrosis, such as lipid emboli, adipocyte hypertrophy, venous thrombosis, increased intraosseous pressure and resorption of bone.

Early decompression of bone (core decompression) is the treatment of choice in the early stages, before irreversible damage has taken place. The rationale for the use of core decompression is based on the concept that increased intramedullary pressure is involved in the pathogenesis of avascular necrosis. The aim of the proponents of core decompression is to decrease the intramedullary pressure and thus arrest or reverse the process of avascular necrosis before it is evident.⁹⁷ Cortical bone grafting can be added to the core decompression in an effort to provide structural support for the subchondral bone and articular cartilage, and to prevent collapse during the repair process. A meta-analysis of 24 reports analysing 1206 hips treated by core decompression with or without cancellous bone grafting revealed an overall clinical success rate of 63.5% (range 33–95%). Less than 33% of the hips required a replacement or salvage procedure during the follow-up period.⁹⁸

In stage III, an osteotomy can be performed to rotate the necrotic or collapsing segment of the hip out of the weight-bearing zone, replacing it with a segment of articular cartilage of the femoral head supported by healthy viable bone. In addition to the biomechanical effect, osteotomy may also reduce venous hypertension and decrease intramedullary pressure.⁹⁹

Symptoms, signs, investigations and treatment of aseptic necrosis of the hip are summarized in Box 47.3.

Stress fracture of the femoral neck

Stress fractures of the femoral neck are not uncommon. The disorder presents in athletes,¹⁰⁰ military recruits^101,102 and the elderly¹⁰³ with specific symptoms and findings. However, the diagnosis can be easily missed.

Patients present with unremitting, localized hip and groin pain without a history of significant trauma or unusual increase in daily activity. As in the initial stages of aseptic necrosis of the hip, there is a discrepancy between the obvious symptoms (localized pain and limping) and the minimal clinical signs. There is a non-capsular pattern with full and painless range of flexion and extension but considerable pain at the end of internal and external rotation of the hip. Resisted movements are painless.¹⁰⁴ The initial radiographic features may prove negative.

An early diagnosis of spontaneous stress fracture of the femoral neck may be made when the scintigraphic examination shows increased focal radionuclide uptake.¹⁰⁵ MRI seems to be the most accurate diagnostic tool in the early detection of a femoral neck stress fracture.¹⁰⁶

The sequelae of undetected spontaneous fractures are subcapital fracture with displacement, angular deformity and avascular necrosis of the femoral head.

Treatment depends on radiological differentiation of the lesion. A transverse stress fracture is potentially unstable and the recommended treatment is prompt internal fixation. The compression stress fracture has a benign prognosis. Restriction of weight bearing for a few weeks is usually sufficient to relieve symptoms. Prophylactic internal fixation should be considered only in cases of significant weakening of the trabecular bone mass.

Internal derangement of the hip

Internal derangement of the hip is not uncommon but is frequently overlooked. It is caused by a loose body, a torn portion of the labrum or impingement of a small focus of synovitis.

Cyriax ⁵ suggested that a small piece of exfoliated articular cartilage, secondary to trauma or osteoarthrosis, becomes loose in the joint. When the fragment lies inside the capsular fold, level with the femoral neck, it is harmless and painless, but when it is pinched at the acetabular edge, sudden twinges result.

During arthroscopy, Dorfmann and Boyer sometimes found a small focus of synovitis on the anterior and anteroinferior aspects of the femoral neck in patients with symptoms of internal derangement. They hypothesized that this was probably due to impingement of the capsule by the psoas muscle tendon.¹⁰⁷

Recent arthroscopic studies suggest that most internal derangement may be the result of impingement of acetabular labral tears.¹⁰⁸ The latter are caused by repetitive contact between a widened femoral neck and the acetabular rim.¹⁰⁹ Most tears are radial flaps located in the anterior section of the acetabulum and are more tag-like than massive.¹¹⁰ Anatomical studies have shown that the labrum is richly innervated with free nerve endings, capable of nociception. This may cause a direct painful response from the nipped flap.¹¹¹

Symptoms

The pathognomonic sensation in internal derangement of the hip is the presence of a ‘twinge’ – a sharp, severe pain in the groin or the trochanteric area. It appears suddenly and unexpectedly during ordinary walking or descending stairs. The patient feels a pain shooting down the thigh to the knee and the leg feels as if it ‘might let the patient down’. Sometimes the pain disappears immediately or the patient has to stand on the good leg for a while.¹¹² This painful twinge may be repeated on each step, some 100 metres later or not at all for the first few weeks. If patients have many twinges a day, they will be severely disabled, because they happen at any moment without warning and nothing can be done to prevent them.

Signs

There is a difference in signs between an impacted loose body in a normal joint and the presence of a loose fragment in an osteoarthrotic joint.

Examination of a joint not complicated by osteoarthrosis shows a full range of movement, with some discomfort at the end of one or two movements – as a rule, external rotation and flexion. As these two movements are also painful in psoas bursitis (see later), the differential diagnosis will be supplied by the existence of twinges and the slightly different end-feel. Some authors report successful diagnosis of impingement lesions with the so-called Thomas test.113,114 This involves flexion and external rotation of the hip, then allowing the extremity to abduct. The hip is then moved into extension, internal rotation and adduction. A positive test result is indicated by a palpable or audible click and the production of pain.

The commonest occurrence of a loose body, however, is as a complication of osteoarthrosis. Unfortunately, these cases are often missed because the twinges mentioned by the patient are usually ignored, all attention being given to the radiograph. Examination not only shows the capsular pattern with the usual hard end-feel but also one or two movements may have a softer end-feel and cause pain. Sometimes only the capsular pattern of osteoarthrosis is present, and then the diagnosis will rely entirely on the characteristic history of twinges.

Current modalities for imaging the hip joint, including arthrography and MRI, are poor at directly identifying a labral tear (sensitivity is between 13 and 24%).¹¹⁵ Indirect MRI findings of labral tears include a large α angle, an osseous bump formation at the femoral neck, a deep acetabulum and posteroinferior or anterosuperior cartilage lesions.¹¹⁶

Treatment

The ultimate proof of the existence of a loose body is the immediate and usually lasting improvement after a manipulative reduction, which means the fragment has been moved to a position within the joint where it no longer becomes ‘nipped’ on movement.

Technique: reduction of a loose body – 1

The manipulation is a combination of three movements conducted simultaneously: a movement towards extension during strong traction, in combination with medial or lateral rotation.

The patient lies supine on a low couch. An assistant presses on both anterior superior iliac spines in order to fix the pelvis firmly to the couch during the whole procedure (Fig. 47.12). To prevent local pain, a thick layer of foam may be placed between the hands and iliac crests. The pressure on the iliac spines should be directed downwards and cranially to withstand the force of the traction.

Fig 47.12 Reduction of a loose body in the hip joint – technique 1: start (a) and end (b) of the manipulation.

The manipulator stands on the end of the couch, holding the patient’s ankle. From this point, the procedure depends on the direction of rotation required.

Medial rotation

The contralateral hand encircles the heel. The other hand is placed at the distal side of the leg, level with the malleoli (Fig. 47.13). This position of the hands is vital in protecting the ligaments of the ankle when rotation is performed. The manipulator raises the outstretched leg to 70 or 80° and leans backwards, inducing as much traction as possible. As soon as the muscles are felt to relax, the manipulator steps gradually off the couch, meanwhile rotating the leg with a jerk to full medial rotation and back to the neutral position as the leg is extended. This manœuvre is repeated three or four times during extension.

Fig 47.13 Position of the hands during medial rotation.

Lateral rotation

The ipsilateral hand is used to grasp the heel. The foot is held at a right angle and the other hand encircles the medial border of the foot (Fig. 47.14). The manipulator leans backwards after having lifted the patient’s leg to about 70°. Again, when the muscles relax, a movement backwards is made and then downwards, meanwhile rotating the leg laterally. At the end of the rotational movement, a sharp jerk is added and the leg is turned back into the neutral position. This rotational movement is performed three or four times as the leg is extended.

Fig 47.14 Position of the hands during lateral rotation.

As a rule, manipulation in the most comfortable direction is done first. After each manœuvre, the joint is re-examined to find out whether there is an improvement. The most effective rotation is then carried out several times during the same session.

Attention should be paid to two important technical points:

• The rotation must have the largest possible amplitude. Thus, starting at least from the neutral position, the leg has to be rotated until the end-feel is reached. It is then rotated back to the initial position, to restart the same procedure.

• Traction should not be lost during extension. Care should be taken to maintain strong traction throughout the whole manipulation until the joint is extended completely. Therefore, the manipulator keeps one foot on the couch, in order to maintain sufficient traction.

Technique: reduction of a loose body – 2

If the previous manipulation did not reduce the subluxated loose body, an alternative technique should then be tried, applying stronger traction and rotation, which can be achieved by using the lower leg as a lever.

The patient adopts a supine-lying position on a low couch. As in the previous manipulation, an assistant holds the pelvis down on the couch, putting all the body weight on the anterior superior iliac spines. The manipulator places the contralateral foot on the couch, just beyond the patient’s buttock, and puts the back of the patient’s bent knee over the thigh. The contralateral hand holds the knee and the other hand grasps the ankle (Fig. 47.15).

Fig 47.15 Reduction of a loose body in the hip joint – technique 2.

Considerable traction on the hip can now be achieved when the lower leg of the patient, used as a lever, is pushed down. This levers the buttock off the couch. In the meantime, the assistant applies as much counterpressure as possible. At the moment the muscles are felt to relax, the femur is rotated by means of the lever provided by the patient’s leg. At the end of range, a quick rotational thrust is added. The direction of rotation can be chosen at random but usually the rotation found to be the most beneficial during the previous manipulation is done first.

Results

This manipulation can have spectacular results. The patient no longer has the repeated twinges that make walking so difficult. This happy outcome can be achieved in two-thirds of patients complaining of twinges at the hip. The osteoarthrosis itself, if present, will not be changed but it seldom causes problems other than a little discomfort after a long walk. As a rule, two or three manipulation sessions will be sufficient. If no improvement is achieved by then, defeat must be conceded and the patient referred for arthroscopy.

Warning

Because the leverage of both traction and rotation is considerable, the manipulation should never be performed in elderly people, for fear of fracture of the femoral neck.

Psoas bursitis

The psoas bursa is one of the largest bursae in the human body.¹¹⁷ Located between the lesser trochanter, the musculotendinous portion of the iliopsoas muscle and the anterior capsule of the hip joint, it can be up to 7 cm long and 4 cm wide.¹¹⁸

As the bursa is derived from the second and third lumbar segments, pain is usually felt in the groin, anterior thigh, knee and leg. It appears during walking and during specific movements: for example, crossing the legs.¹¹⁹ Untreated, the disorder can persist for years.

The lesion is generally overlooked and the symptoms are usually blamed on the slight arthrosis visible on radiograph rather than the (invisible) psoas bursa.¹²⁰ Clinical examination, however, shows a non-capsular pattern: lateral rotation is painful and the end-feel soft, and flexion is slightly painful at the end of range. Sometimes there is also pain at the end of extension or adduction.¹²¹ An accessory test is provided by passive adduction in flexion, which is the most painful movement because it squeezes the bursa. This test also provokes considerable stretching of the sacroiliac ligaments and tissues in the buttock, so it is essential to ascertain that the reproduced pain is in the groin and is not some vague sensation of pulling in the buttock. Resisted movements are strong and painless. The bursa may be palpably enlarged, as is sometimes the case in rheumatoid conditions.^119,122,123

Differential diagnosis should be made from a loose body in the hip and early aseptic necrosis. In the former the patient complains of sudden twinges and in the latter there will often be a gross discrepancy between the functional incapacity and the moderate signs. Ultrasonography is the best confirmatory diagnostic test.¹²⁴

The diagnosis is also confirmed when a diagnostic infiltration with local anaesthetic is found to abolish the clinical features. This injection, perhaps repeated once or twice, is very often therapeutic too.¹²⁵

Technique: infiltration

The patient adopts a half-lying position on the couch, keeping the legs outstretched, which relaxes the tissues at the groin. Three landmarks are identified: the anterior superior spine of the ilium, the femoral artery and the greater tuberosity. A perpendicular line is drawn from the anterior superior spine, and a horizontal line 5 cm under the tip of the greater tuberosity. The needle is inserted at the crosspoint, which is well lateral to the inguinal vessels.

A needle 7 cm long is fitted to a 50 mL syringe, filled with procaine 0.5%. The needle is inserted at the identified spot, and thrust in at a 45° medial and upward direction (Fig. 47.16).

Fig 47.16 Infiltration of the psoas bursa.

At the same time, the free hand is used to palpate the femoral artery continuously as a safeguard to avoid the inguinal vessels. If the tip of the needle hits bone, it lies near the junction of the femoral head and neck; this is where the infiltration is given, using the classic technique of withdrawals and reinsertions. If the needle pierces the capsule, it must be withdrawn a little until the drug can be placed without resistance.

Results

Diagnostic infiltration often has a lasting therapeutic result, regardless of the duration of symptoms. If necessary, the infiltration can be repeated once or twice, at weekly intervals. If no lasting relief is afforded and the injection only acts temporarily, 50 mg of triamcinolone should be injected at the same site at the next attendance.¹²⁶

Haemorrhagic psoas bursitis

As in haemorrhagic bursitis at the shoulder, this condition sometimes occurs in the elderly. The patient states that the hip was hurt during a sideways slip of the leg, which was immediately followed by extreme pain at the front of the thigh and knee. Spontaneous haemorrhage complicating a pigmented villonodular synovitis of the bursa has also been reported.¹²⁷

Examination shows a gross non-capsular pattern, with up to 90° limitation of flexion and gross limitation of lateral rotation and extension, but almost a full range of medial rotation.¹²⁸ Resisted movements are full-range and painless. Sometimes a tense, tender swelling can be palpated in the groin. Aspiration confirms the diagnosis and is also the required treatment.

Gluteal bursitis

This syndrome, also referred to as ‘greater trochanteric pain syndrome’, is one of the most frequent causes of pseudoradicular pain in the limb.¹²⁹ The condition most frequently occurs in late-middle-aged females and shows little tendency to spontaneous cure.¹³⁰ Patients are usually in their forties or fifties and complain of pain at the gluteal or tronchanteric area, spreading to the outer or posterior thigh and down to the calf muscles and outer malleolus.¹³¹ Unlike the pain caused by a disc lesion, the symptoms are not related to sitting but to walking, prolonged standing or transitioning to a standing position.¹³² They are also exacerbated by sitting with the affected leg crossed and by climbing stairs.¹³³ The patient will not mention the twinges that are so typical of an impacted loose body but may state that a particular movement causes a sharp pain down to the leg. Sometimes the patient has nocturnal pain when lying on the affected side. Sitting with the painful leg crossed over the other also hurts.¹³⁴ Coughing is painless. The combination of long-standing leg pain, related to hip movements and without symptoms typical of disc lesions, suggests the existence of gluteal bursitis.¹³⁵

There is a full range of movement but some movements hurt in a non-capsular way at the end of range. The end-feel is normal. Some resisted movements may be painful because they squeeze the tender bursa. A typical pattern is pain on passive external rotation and passive abduction and resisted external rotation or resisted abduction.136,137 Pain on resisted hip movements may be explained by compression of the bursa. However, recent histopathologic findings show that tendinopathy and bursa pathology may coexist in greater trochanteric pain syndrome.¹³⁸

Most of the affected bursae are located near the greater trochanter and between the gluteus maximus and gluteus medius (Fig. 47.17).

Fig 47.17 The bursae at the greater trochanter.

Localization depends on the findings on palpation, although sometimes the approximate area can be deduced from the general examination: when full passive internal rotation together with resisted external rotation causes pain, the bursa at the insertion of the piriformis is affected; pain on passive abduction and passive flexion, together with resisted abduction, indicates that the bursa between the gluteus medius and gluteus maximus is at fault.¹³⁹ Caution is required in drawing conclusions from palpation. Because the gluteal region is an awkward area and the affected tissues lie deeply, tenderness can be elicited in a normal buttock if the pressure applied is considerable. It is therefore always wise to compare the unaffected side with the affected one.

During the last few decades there has been increasing use of ultrasonography and MRI for visualizing lesions of the greater trochanteric area. It should be mentioned, however, that several studies identified gluteal abnormalities in asymptomatic hips,140–142 sometimes in as many as 60%.¹⁴³ It is therefore unwise to rely entirely on the result of these tests to establish the diagnosis.¹⁴⁴

The diagnosis is settled by local anaesthesia. If, after infiltration, the movements known to hurt are tested again and are no longer painful, the right point has been found.¹⁴⁵ This diagnostic injection often has a lasting result; therefore the patient should re-attend after a week for re-examination. If there is considerable and lasting relief, the injection is repeated two or three times at weekly intervals. If there is no therapeutic result, 50 mg of triamcinolone is injected in the same site. This injection may also have to be repeated once or twice but this time at an interval of 2 weeks.¹⁴⁶ Sometimes an intractable case is encountered; though injections relieve the symptoms for 2 or 3 weeks, the latter subsequently recur; as operative exploration of the buttock is a very difficult procedure and rarely effects a cure, it is best to admit defeat and hope a spontaneous remission will take place.¹⁴⁷

Technique: injection – 1

When the patient has evidence of a highly localized bursitis, the lateral approach is used (Fig. 47.18). The patient lies prone and the physician sits or stands on the affected side. A 7 cm needle is fitted to a syringe containing 50 mL of procaine 0.5%. The tender area is localized and the needle inserted horizontally until it reaches the ilium. It is then withdrawn by 1 or 2 cm and a large area is infiltrated using the classic technique, employing withdrawals and reinsertions at different angles.

Fig 47.18 Infiltration of a gluteal bursa by technique 1 (a) and technique 2 (b).

Technique: injection – 2

When the bursitis is located at the upper or inner edge of the trochanter, this alternative technique must be used. The patient lies prone on a high couch but with the affected thigh hanging vertically downwards over the edge. In order to support the leg, a low support is placed under the bent knee. Slight adduction of the hip is preferable in order to make the inner portion of the trochanter more accessible. In this position, it is easy to palpate the upper part of the trochanter from above.

The tender spot is identified. The needle is inserted from above and medially, and thrust downwards until the tip touches bone. It is then slightly withdrawn and the affected area is infiltrated all over with 50 mL of procaine 0.5%.

Trochanteric bursitis

The trochanteric bursa (Fig. 47.19) lies at the lateral aspect of the trochanter tip, between the iliotibial tract and the bone, level with the insertion of the gluteus medius and the tensor fasciae latae. It can become inflamed after a local blow,¹⁴⁸ although trochanteric bursitis may also result from overuse in long-distance runners.¹⁴⁹ The incidence of trochanteric bursitis peaks between the fourth and sixth decades of life and is more common in women (male : female ratio 1 : 10).¹⁵⁰