Between 1965 and 1973 a total of 808 McKee-Farrar metal-on-metal cemented total hip arthroplasties were performed in the Norfolk and Norwich Hospital. Of these, 230 surviving arthroplasties have been reviewed at average follow-up of 13.9 years. There were good or excellent results in 49% of the arthroplasties as judged by the Harris hip score with 78% of these having little or no pain. A comprehensive radiographic analysis was undertaken and a survivorship study of 81% of the total number of prostheses is presented.

A retrospective study was made of the results of surgical treatment of subluxation or dislocation of the hip in patients who had suffered from poliomyelitis. Good results were achieved in 46% and satisfactory results in 24%. The key factors for success are muscle balance, the femoral neck-shaft and anteversion angles, and the acetabular geometry. Iliopsoas transfer can augment the hip abductor power by an average of one MRC grade. Varus derotation femoral osteotomy is important to re-establish a normal neck-shaft angle and anteversion. The results of pelvic osteotomy are variable and the importance of a posterior acetabular defect is emphasised.

Forty-four children, treated conservatively for fracture of the shaft of a femur, were studied radiographically to assess the consequent increase in longitudinal growth of the bone. Overgrowth averaged 8.1 mm and was shown to be significantly greater in boys than in girls. Overgrowth did not appear to be influenced by the age of the patient, the type of injury, the type or site of the fracture, the amount of overlap of the fragments or by the handedness of the patient.

Of 92 children reviewed three to five years after treatment for fractured neck of femur (Lam 1976), we have been able to reassess 41, both clinically and radiographically, at 13 to 23 years after injury. The earlier clinical results had been excellent, despite a high incidence of complications; but the new, later review shows an 83% incidence of radiographic abnormality while 24% of the patients have pain, a limp or leg shortening. We present a recommended policy for management of this rare but potentially serious childhood injury.

Evidence is presented to support the contention that after slipping of the upper femoral epiphysis there is a potential for the bony epiphysis to grow back to its pre-slipped position. A suggestion is made as to how this recovery may occur.

We have compared, in rabbits, two techniques of limb lengthening by distraction of the epiphyseal plate using a unilateral external fixation frame. In all cases, 14 mm of symmetrical lengthening without deviation was achieved. With rapid distraction at rates of 1 mm per day (distractional epiphyseolysis) separation of the epiphysis from the metaphysis occurred by day 7, and by day 70 almost complete ossification of the cartilage and the elongated segment was evident. In contrast, slow distraction at 0.25 mm every 12 hours (chondrodiatasis) produced hyperplasia of growth cartilage without any evidence of detachment at 28 days, the end of the distraction period. By day 70 the epiphyseal plate had returned to normal thickness with normal cellular morphology, while the lengthened segment was occupied by ossified tissue. The significance of these findings is discussed.

We describe a technique for slow, progressive, symmetrical distraction of the growth plate using a lightweight dynamic axial fixation system. Results are given for the elongation of 40 bony segments in children with limb-length discrepancies and 60 segments in children with achondroplasia or hypochondroplasia. Increases in limb length of up to 36% were obtained in non-achondroplastic and up to 64.5% in achondroplastic patients. There were no nerve or vascular lesions or bony infections and no case required a bone graft. Pin-track complications occurred in only 1.5%.

In a randomised prospective trial 98 elderly women with trochanteric fractures of the femur were treated with either a 135 degrees Jewett nail-plate or a 135 degrees Dynamic hip screw. The results at six weeks, three months and six months were statistically analysed. There were no significant differences in the two groups with regard to pain, length of hospital stay, morbidity or mortality. Although operative difficulties and open reduction were more common with the Dynamic hip screw, at the end of six months more patients in this group were mobile and there was significant radiological evidence of better compression without loss of fixation.

Deformity of the forearm is common in patients with hereditary multiple exostoses, producing cosmetic and functional impairment in which shortening of the ulna is a significant factor. The results of ulnar lengthening in 10 forearms of eight patients are reported. Lengthening was performed by osteotomy of the shaft followed immediately by a bone graft and internal fixation, or by gradual distraction with an external fixator. In all patients the appearance was improved and the range of radial deviation at the wrist was increased. In most patients forearm movement and radial head stability were improved. Partial recurrence of the deformity was seen during the follow-up of skeletally immature patients, but in general ulnar lengthening was found to be a useful operation.

Sixty unconstrained elbow replacements of a new design have been followed prospectively for three to nine years. Review showed that 50% had excellent relief of pain and return of function, 27% had had major complications requiring removal or revision of the prosthesis and 23% had minor complications which marred the result. Further research in this field seems worthwhile.

We have reviewed the notes and radiographs of 57 patients with fractures of the proximal humeral epiphysis and examined 30 of them at 2 to 8 years after injury. Regardless of treatment the maximum shortening of the humerus was 2 cm and residual varus angulation was insignificant. Manipulation of a displaced, fresh fracture did not improve the final outcome with respect to humeral growth or function; and open reduction is very rarely indicated.

A 10-year-old boy who sustained a fracture through a cyst in the ulna later developed a pseudarthrosis. During 13 years' follow-up the characteristic short bowed forearm developed but, instead of the more usual spontaneous dislocation of the head of the radius, the patient also developed the previously unreported complication of osteoarthritis of the elbow.

Ninety-eight children with severely displaced supracondylar fractures of the humerus were treated by straight lateral traction. After a mean follow-up period of 3.5 years there were 90 satisfactory and only eight unsatisfactory results. Cubitus varus was present in only four children, which compares favourably with the results of operative treatment. The indications for straight lateral traction, and the advantages of this method, are discussed.

We have reviewed 61 children treated for septic arthritis from 1972 to 1981. The diagnosis in all cases was confirmed by bacteriology or by radiographic changes. Routine arthrotomy was not performed, but most patients had a joint aspiration. The management and outcome are described. We suggest that arthrotomy should be selective rather than mandatory. Septic arthritis of the hip in infants requires arthrotomy, but in the older child an infected hip can be treated by aspiration if the duration of symptoms is less than four days; arthrotomy may be needed if there has been more delay. Infected joints other than the hip can be satisfactorily managed by aspiration.

We studied 104 patients with a total of 154 hemivertebrae which had produced scoliotic curves. Of the hemivertebrae 65% were of a fully segmented (non-incarcerated) type, 22% were semi-segmented and 12% were incarcerated. We found that the degree of scoliosis produced depended on four factors: first, the type of the hemivertebra; secondly, its site; thirdly, the number of hemivertebrae and their relationship to each other; and finally, the age of the patient. Semi-segmented and incarcerated hemivertebrae usually do not require treatment. Fully segmented non-incarcerated hemivertebrae may require prophylactic treatment to prevent significant deformity.

Thirty-four bony specimens of isthmic spondylolysis were examined and, in a significant number (32%), stenosis of the intervertebral foramen was noted. Although not emphasised in previous reports, this finding may be an important factor in the aetiology of nerve root compression when this is associated with spondylolysis and spondylolisthesis. Anatomical guidelines for adequate surgical decompression are suggested.

The Denham knee replacement is a relatively simple unconstrained prosthesis. The design ensures good alignment and full extension, but does not allow flexion beyond 90 degrees or tibiofemoral rotation. The results after eight years' experience have been assessed in four different ways in over 600 cases. They show that for the limited needs of the elderly arthritic patient, the Denham arthroplasty provides a high proportion of satisfactory results with an unusually low rate of late failure.

The accurate assessment of compartmental involvement in degenerative arthritis of the knee is important when planning operative treatment. Standard radiographic techniques often fail to define the degree of involvement of the less affected tibiofemoral compartment. The use of stress radiography in the preoperative assessment of 30 knees with degenerative arthritis is described and the radiographic findings correlated with the changes found at arthrotomy.

A series of 42 ankle fractures have been randomised into two groups respectively undergoing either open reduction and internal fixation or manipulative reduction and plaster. Their progress after removal of all external splintage has been followed using simple gait analysis techniques. There appears to be no difference in the outcome of treatment of the two groups in the early recovery period (up to 20 weeks).

The reliability of the Catterall grouping of Perthes' disease was examined by determining the agreement between pairs of observers using weighted kappa statistics. Anteroposterior and lateral radiographs of 100 hip joints were grouped independently by four experienced observers. There was a low, and in our opinion, unacceptable degree of inter-observer agreement even when Groups 2 and 3 were combined.

Three brothers with the X-linked variety of spondylo-epiphyseal dysplasia tarda are presented. Their clinical courses differed: one was relatively free of symptoms, the second had slowly progressive osteoarthritis of the hip, and the third had an acute, disabling arthritis necessitating total hip arthroplasty. The clinical features of this disorder are reviewed.

Ischaemia kills osteocytes, but opinions differ as to how long they can survive. These differences are due to the varying methods of inducing ischaemia, and to the different criteria for diagnosing cell death. Using rabbit bone and a technique of in vitro ischaemia at 37 degrees C, we have shown by electron microscopy that, after up to two hours, the changes which occur are probably reversible; after four hours, the cells were irreversibly damaged. This difference could not be detected by light microscopy. After 24 hours of ischaemia, most lacunae were empty or contained only osteocyte debris. We conclude that osteocytes suffer irreversible damage after in vitro ischaemia of about two hours, which is much the same response as that of most other mammalian cells.

An unusually wide pneumatic tourniquet has recently become available; we provide a simple formula for its use with a low but effective inflation pressure. A prospective, randomised and controlled trial in 600 lower limb and 150 upper limb operations is reported. The wide tourniquet (12.5 cm) was as effective at low pressure as was a conventional tourniquet (9 cm) inflated to significantly higher pressures. Fewer patients suffered from painful paraesthesiae after operation using the broad, low-pressure tourniquet.

Experimentally produced fractures in long bones studied by light and electron microscopic histochemistry were found to heal by a process of enchondral calcification. There was intense proliferation in the cells of the cambium layer of the periosteum, with differentiation to chondroblasts and osteoblasts, suggesting that this layer was the primary tissue responsible for development of the callus. Cytoplasmic processes of the hypertrophic chondrocytes appeared to bud and produce matrix vesicles. Alkaline phosphatase activity was detected along the plasma membrane of the hypertrophic chondrocytes and around the matrix vesicles, before any signs of mineral deposition. Calcification took place by deposition of hydroxyapatite crystals in and around these matrix vesicles which frequently showed alkaline phosphatase activity. It is suggested that there is a close functional association between alkaline phosphatase activity and calcification in the process of fracture healing, which is another type of enchondral calcification mediated by matrix vesicles.

In dogs, resection of a length of the ulna equal to twice the diameter of the mid-shaft leaves a defect which consistently fails to unite. In response to an implant of 100 mg of bovine bone morphogenetic protein (BMP), the defect becomes filled by callus consisting of fibrocartilage, cartilage and woven bone within four weeks. The cartilage is resorbed and replaced by new bone in four to eight weeks. Woven bone is then resorbed, colonised by bone marrow cells and remodelled into lamellar bone. Union of the defect is produced by 12 weeks. Control defects filled with autogeneic cortical bone chips unite after the same period. In regeneration induced by bone morphogenetic protein (BMP) and in repair enhanced by bone graft, union depends upon the proliferation of cells within and around the bone ends. Our working hypothesis is that BMP induces the differentiation of perivascular connective tissue cells into chondroblasts and osteoprogenitor cells and thereby augments the process of bone regeneration from the cells already present in the endosteum and periosteum.

Radiopharmaceuticals have been successfully used to detect occult neoplasms and infective lesions. Bone scans using 99mTc-labelled methylene diphosphonate located osteoid osteomas accurately in a series of 30 symptomatic patients. A portable radiation detector system has been designed to help intra-operative localisation and facilitate complete excision of the lesions with minimal damage to normal tissue. A sodium iodide detector with a fibre-optic link was used at first, but a cadmium telluride system has provided a more durable, reliable and sensitive sterilisable probe.

To detect sepsis in the painful joint, autologous granulocytes labelled with indium-111 were used to scan 60 patients with 74 prosthetic joints. All 18 patients with confirmed sepsis had positive scans, that is, migration of granulocytes into the region of the prosthesis. Of the 22 sterile arthroplasties 20 had negative scans. In 34 cases there was good correlation between the clinical impression and the result of the scan. We suggest that indium granulocyte scintigraphy is a reliable method of detecting an infected prosthesis.