Photoelastic techniques were used to study the stresses in models which represented the central frontal plane of a normal hip joint. The pelvis and the femur were inclined and the direction of the resultant thrust on the joint was estimated. Inward tilting of the pelvis causes a force which tends to push the head of the femur out of joint. The load distribution on the joint is not significantly changed if the line of action of the load is moved relative to the joint. The directions of the lines of principal stress in both bones are shown

Aims

Modular dual mobility (DM) prostheses in which a cobalt-chromium liner is inserted into a titanium acetabular shell (vs a monoblock acetabular component) have the advantage of allowing supplementary screw fixation, but the potential for corrosion between the liner and acetabulum has raised concerns. While DM prostheses have shown improved stability in patients deemed ‘high-risk’ for dislocation undergoing total hip arthroplasty (THA), their performance in young, active patients has not been reported. This study’s purpose was to assess clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) in young, active patients receiving a modular DM acetabulum and recently introduced titanium, proximally coated, tapered femoral stem design.

A fracture of the neck of the radius when the head is not ossified can be difficult to assess and treat. In a four-year-old child we suspected from the radiographs that there was an O’Brien type-III injury after trauma. Partial manual reduction of the non-ossified radial head was completed using the Métaizeau technique of intramedullary Kirschner (K-) wiring aided by intraoperative arthrography. The child had a full range of movement at the elbow and wrist when reviewed 11 weeks after the injury, three weeks after removal of the K-wire. We suggest that intraoperative arthrography is a useful complement to the Métaizeau technique for successful reduction of fractures of the radial neck in the presence of a non-ossified radial head

Symptomatic impingement of the rotator cuff between the humeral head and the coracoid process has been studied and three varieties recognised: idiopathic, iatrogenic and traumatic. In all three the clinical findings consisted of pain in front of the shoulder, referred to the upper arm and forearm, and especially felt during forward flexion and medial rotation; the pain could be reproduced by medial rotation with the arm in 90 degrees of abduction, or by adduction with the shoulder flexed to 90 degrees. Patients were relieved of their symptoms by restoring adequate subcoracoid clearance

1. Locking of the metacarpo-phalangeal joint from articular derangements is rare. 2. A case due to an intra-articular loose body is described. 3. The literature is reviewed. The commonest cause is catching of the volar capsule or collateral ligaments on osteophytes about the metacarpal head, but intra-articular bands, incongruities of the articular surface and entrapment of the sesamoid have also been described. 4. An analysis of the reported cases suggests the likely cause in the individual patient. 5. Operation is usually required to restore joint motion

1. Congenital coxa vara and infantile coxa vara must be separated as distinct entities. 2. Infantile coxa vara is likely to be due to distal movement of the head fragment relative to the shaft and neck. This can result either from severe trauma in normal bone or from shearing stress on an abnormal femoral neck. 3. There is no justification for considering infantile coxa vara as congenital, developmental or due to interruption of ossification. The nature of the pathological lesion at the epiphysial line in some children is unknown

1. Nineteen patients with congenital shortening of the femur without associated coxa vara have been examined and discussed. 2. The diagnosis is made on finding a short, bulky thigh, held in lateral rotation. The radiographs commonly show no abnormality apart from shortening, but delay in ossification of the head of the femur, with lateral bowing and cortical sclerosis of the shaft, are occasionally present. The overall shortening of the limb seldom exceeds three inches. 3. The place of various surgical procedures to control limb length is briefly discussed

1. A lateral intermuscular approach to the hip joint is described for replacement of the head of the femur by a prosthesis. 2. Advantages claimed for it are that it is attended by little or no shock, because the operation is rapid and relatively bloodless; that adequate exposure can be gained without dividing muscle or tendon; and that muscle function is unimpaired and so walking can be allowed early. The exposure is easily extended if unexpected difficulty is encountered. 3. Prosthetic replacement of the femoral head through this incision is advocated as a primary measure for elderly or unfit patients with fractured femoral neck

Between 1971 and 1991 we treated 98 patients with giant-cell tumours, 15 of whom presented with a pathological fracture. They were most common around the knee (12). Nine fractures were intra-articular. The tumours were treated by curettage and acrylic cementing (10), excision and endoprosthesis (1), excision and allograft (1), curettage and autologous graft (2) or by resection of the fibular head (1). Four patients had local recurrence, three of whom were cured by repeat curettage and cementing. Pathological fracture through a giant-cell tumour is not a contraindication to treatment by curettage and acrylic cementing

1. One hundred and twenty-six metacarpo-phalangeal joints affected by rheumatoid arthritis were studied macroscopically at either synovectomy or arthroplasty. 2. The sites and extent of the initial erosion corresponded with the sites and size of the synovial pouches. 3. The areas of cartilage degeneration were related to the degree of flexion, ulnar deviation and subluxation of the proximal phalanx on the metacarpal head. 4. The routine radiographic findings were not a true reflection of all the pathological changes within the joint. 5. It is suggested that by encouraging joint movement and preventing deformity the degree of cartilage degeneration may be diminished

1. Eighty-nine cases of Perthes' disease are reviewed. 2. The prognosis varies with the amount of the epiphysis involved. 3. It is possible to assess the amount of epiphysial involvement by a study of the early radiographs. Cases were allocated to four groups on this basis. 4. It is confirmed that both sex and age at the time of diagnosis influence the final prognosis. The reasons for this are discussed. 5. The concept of "the head at risk" is suggested and radiological signs described to diagnose such cases. 6. It is hoped that the classification suggested may in future act as a basis for comparisons of treatment

1. Fifty-two patients with Perthes' disease (affecting both hips in six instances) have been reviewed ten or more years after the beginning of treatment. 2. Judged radiographically, approximately one-third developed good, one-third fair and one-third poor femoral heads. 3. The clinical results paralleled the radiographic. Except with the worst shaped heads, function was excellent. 4. Certain constant early and late radiographic features are recorded. 5. Of the factors influencing prognosis, the age at onset of the disease and the sex of the patient appear to be important

1. The "frozen" shoulder syndrome is due to an inflammatory lesion in the musculotendinous cuff invoked by a local area of degeneration. 2. The available evidence suggests that the primary site of the degenerative lesion is in the supraspinatus tendon. 3. Other causes of shoulder pain which must be differentiated from "frozen" shoulder are peritendinitis of the long head of biceps, degeneration or tears of the supraspinatus, and calcified deposits in the supraspinatus. 4. An explanation of the pathogenesis of lesions of the musculo-tendinous cuff is submitted in which the different types of clinico-pathological syndrome are correlated. This hypothesis is in accord with the experimental, clinical and operative findings

Existing classifications of fractures of the head of the humerus are inadequate in terms of interobserver reliability and the predictability of the clinical outcome. From a combined study of 73 fracture specimens in museums and 84 CT-three-dimensional reconstructions in patients, we have devised a classification which appears to be more useful clinically. Common patterns of fracture and a plausible mechanism of injury were observed. In 3-D most proximal humeral fractures can be organised into five basic types. These correspond in some degree to the Codman/Neer classification, but differ significantly in regard to the more complex patterns of fracture. We observed a logical progression from simple to complex fractures. An interobserver reliability study was carried out which indicated the improved usefulness of this new 3-D concept in providing a common language among clinicians for classifying these injuries. When surgery is indicated, the 3-D concept is also invaluable in guiding the restitution of anatomy through either open or percutaneous means

We studied the natural history of nontraumatic avascular necrosis of the femoral head (ANFH) in 115 hips in 87 patients, 69 steroid-induced, 21 related to misuse of alcohol and 25 idiopathic. The average length of follow-up was over five years. Collapse occurred most often when the focus of bone necrosis occupied the weight-bearing surface of the femoral head. Flatness of the head due to subchondral fracture was an early manifestation of collapse. Classification into six types based upon the radiographic findings provided an accurate prognosis for individual cases of ANFH which is useful in planning treatment and in assessing its outcome

We aimed to find out whether the Hastings bipolar prosthesis moved in a bipolar fashion after its use for displaced fractures of the femoral neck. In 65 patients non-weight-bearing movement was assessed radiographically and compared with an earlier study of the Monk prosthesis. In 70% of patients, the only movement was between the acetabulum and the prosthetic shell, the prosthesis behaving as if it were unipolar. This did not change with time, but there was a slight improvement in the range of movement, particularly in flexion. The absence of movement between the outer shell and the metal head is most probably due to the design of the prosthesis and makes this prosthesis unsuitable for use in osteoarthritic hips

Fourteen cases of hemiarthroplasty for four-part fractures of the proximal humerus were reviewed. Pain relief was satisfactory, but function was limited, mainly due to loss of glenohumeral abduction despite electromyographic proof of actively contracting abductors in all cases. Analysis of special radiographs of nine cases showed a direct relationship between the clinical results and the "humeral offset", or distance between the geometric centre of the humeral head and the lateral aspect of the greater tuberosity. This offset affects the lever arms of the glenohumeral abductor muscles. The implications for surgical technique and for the design of shoulder prostheses are discussed

We performed single-photon-emission CT (SPECT) and planar bone scans to assess femoral head vascularity in ten patients with displaced intracapsular hip fracture. The heads were labelled with tetracycline and after excision at hemiarthroplasty were assessed for tetracycline uptake distribution by fluorescence under UV light. The four which had the greatest tetracycline uptake were normal on SPECT and planar imaging. In two cases the planar bone scans were normal although SPECT suggested avascularity thus giving false-negative results. Surgeons should be aware of this; SPECT may prove to be a more accurate method of assessing vascularity of the femoral head in fractures of the femoral neck

We dissected 21 cadaver elbows to determine the relationship of the posterior interosseous nerve to the posterolateral approach to the elbow and head of the radius. At the distal end of the exposure the first branches at risk, those to extensor carpi ulnaris, were on average 6.0 ± 1.0 cm (4.0 to 8.4) from the articular surface of the radial head. When using the posterolateral approach it is important that the interval between extensor carpi ulnaris and anconeus is clearly identified with the forearm fully pronated. The supinator should be released close to its ulnar border. It is safe to expose the proximal radius as far as the distal aspect of the bicipital tuberosity

We used radiostereometric analysis to compare wear rates between uncemented porous sockets and cemented all-polyethylene sockets in a series of 102 hips randomised for either a Harris-Galante or a Charnley cup. Wear was evaluated in 95 hips at a mean of five years (2 to 7). All hips had a cemented, 22 mm head mono-bloc Charnley stem. The mean annual wear rate was 0.09 mm in the Charnley sockets and 0.10 mm in the Harris-Galante sockets, with no statistically significant differences in wear, migration or rotation. We conclude that, up to five years, the wear characteristics of the modular and porous Harris-Galante socket resemble that of the Charnley socket