We have reviewed 82 children with congenital dislocation of the hip, after treatment by anterior open reduction followed by derotation femoral osteotomy. The clinical and radiological results were significantly better in the group that had open reduction before the appearance of the capital femoral epiphysis; this group also had a lower incidence of avascular necrosis. We conclude that, when it is clearly indicated, the earlier an open reduction is carried out the better the results.

Computerised arthrotomography was performed on 33 patients four to six weeks after acute primary anterior dislocation of the shoulder. Seventeen patients were under, and 16 over 50 years of age. Damage to the anterior glenoidal labrum was seen in all the younger patients and in 75% of the older ones. A large redundant capsular pouch, seen in the older patients, was present in 35% of the younger ones, and a posterior humeral head defect was seen in 82% of the younger patients and only 50% of the older. Associated fractures were more common in the older patients, and a tear of the rotator cuff was demonstrated in 63% of the older patients and in none of the younger ones.

We used ultrasound to investigate the anatomy and stability of the hip during the phase of joint stabilisation after closed reduction of unilateral late CDH in 15 infants aged from two to 15 months. Conservative treatment by splintage in abduction led to complete stability in all hips in from three to 13 weeks. Immediately after reduction, interposed soft tissue caused lateralisation of the femoral head, but this progressively disappeared, and the initially smaller femoral head on the dislocated side regained normal size. Ultrasonic evaluation of the hip in late CDH is a valuable and safe tool; it reduces the need for radiographic examination and improves treatment by visualising the actual pathology. The more frequent use of ultrasound can reduce the need for open reduction in the age group that we studied.

The exact measurement of femoral head cover is essential for an assessment of reduction of congenital dislocation of the hip. We have compared standard anteroposterior radiographs with computerised tomograms and thereby classified the shape of the acetabular roof into four types. We found that the CE angle of Wiberg is a more reliable measure of head cover when the lateral point of bony condensation of the roof is chosen as the reference point rather than the edge of the bone, where these two points do not overlap. We conclude that head cover can be more accurately determined in younger children with dysplastic hips by our 'refined' CE angle, than by the original method of Wiberg.

One-hundred newborn children at high risk of hip instability were prospectively assessed clinically and by ultrasound. The decision to treat was based only on the clinical examination. At the age of three months all the children were evaluated clinically and with an anteroposterior radiograph of the pelvis. None of the standard ultrasound measurements of acetabular depth and femoral head cover correlated with the outcome at three months. Dynamic assessment of stability was the only ultrasound technique that had a significant relation with outcome.

Fifteen independent observers of three levels of experience (consultant staff, fellows, residents) assessed 40 radiographs of children presenting with Perthes' disease using the Catterall and the Salter-Thompson grading systems. Each observer was supplied with descriptions and illustrations of the classifications and each hip was grouped by both systems by each observer. The results were statistically analysed using 'kappa' statistics. The level of interobserver agreement was higher for the Salter-Thompson system and correlated with the level of experience of the observer. Both systems can give acceptable levels of interobserver agreement, but the Salter-Thompson grouping is simpler and easier to apply in the earlier stages of the disease when treatment must be decided, and has a higher degree of reproducibility amongst more experienced observers.

We report the short-term results of 100 cementless total hip replacements in 52 severely dysplastic and 48 totally dislocated hips, with some new technical solutions to the problems involved. In cases with a very narrow iliac bone, the acetabular screw ring is seated below the true cotyloid area. In hips with tight flexor and abductor muscles or with deformities of the proximal femur, various osteotomies were performed. Special attention was paid to careful pre-operative planning and precise operative technique. In spite of a high complication rate the results were generally good and even patients who required reoperation were satisfied with the final result.

In 16 patients we used uncemented Lord prostheses at revision operations for aggressive granulomatosis after cemented hip arthroplasties; in 12 bone grafts also were used. In 13 hips the granulomatous lesions were multifocal, and in one the acetabular component was involved. There was no evidence of infection in any case: all the patients had normal ESR and CRP levels. The revision operation was performed on average 9.4 years after the primary replacement; the mean age at revision was 64 years. On radiographs, the bone around the prosthesis had consolidated by an average of 16 months. At follow-up, two to six years later (mean 3.5 years) there had been no recurrences, nine patients had an excellent Mayo hip score, five were good and two fair.

We report the complications of prophylactic pinning of slipped upper femoral epiphysis with Crawford Adams pins in 95 cases. Complications of pin placement were seen in 13.7%. Although seven hips had penetration of the joint, there were no cases of chondrolysis or avascular necrosis. Excavation of the lateral femoral cortex was required at pin removal in 12.5% of cases. Analysis of the growth around pins allowed recommendations to be made regarding pin protrusion. The use of improved fixation devices may reduce the need for multiple pins.

We have reviewed 15 patients with infected total knee replacements after removal of the prosthesis, rigorous debridement, antibiotic irrigation, and prolonged systemic antibiotics. Infection was permanently eradicated in all patients; they were left with a functioning limb, on which they could walk with either a caliper (8 patients), a simple splint (3), crutches, or sticks. Three were disappointed because of residual pain. We believe that, if exchange arthroplasty is inappropriate, this procedure is preferable to arthrodesis or amputation for persistent and disabling infection, particularly where constrained artificial joints have been used.

We evaluated the accuracy of six clinical tests for posterior instability in 24 knees with acute surgically-proven posterior cruciate ligament injuries and intact anterior cruciate ligaments. We also performed stress radiography under anaesthesia. The gravity sign and the posterior drawer test in near extension and its passive reduction were diagnostic in 20 of the 24 knees, and the active reduction of posterior subluxation was diagnostic in 18. The reversed pivot shift sign helped to diagnose severe posterior and posterolateral subluxations, but the external rotation recurvatum test was negative in all 24 knees. Stress radiography in near extension revealed a highly significant increase in posterior tibial subluxation in the injured knees.

We have reviewed 16 patients with avulsion fractures of the tibial tubercle, mostly boys who sustained left-sided injuries during sport. Two-thirds had type I or II injuries and were treated conservatively. Fractures involving the knee joint (type III) had internal fixation. The final results were good except for minor complications such as a prominent and uncomfortable tibial tubercle.

Varus osteotomy of the distal femur is recommended for osteoarthritis of the knee with significant valgus deformity, but the operation is difficult to plan and perform. A simple technique involving a jig referenced to the line of the tibia is described. This allows accurate overcorrection by a few degrees, with impaction and secure fixation at the osteotomy. It has been successful, with no complications, in 12 consecutive knees.

On three occasions we have reviewed a series of knees after high tibial osteotomy for osteoarthritis: 99 were reviewed at one to two years; 81 at a mean of 5.7 years; and 65 at a mean of 11.9 years. At one to two years and at 5.7 years over 50% were good and over 75% acceptable. At 11.9 years, 43% were good and 60% acceptable. We determined the mechanical axis through the knee in maximum varus and maximum valgus; significantly better results were found if a mean angulation of 3 degrees to 7 degrees of valgus had been achieved at operation. We also measured intercondylar distances under varus and valgus stress, and found no significant lateral compartment narrowing. The best results were seen in knees with pre-operative grade I or grade II osteoarthritis and valgus deviation after osteotomy.

The importance of well-functioning toes has long been recognised but has not previously been assessed in biomechanical studies. We have examined the weight-bearing function of the foot in 160 normal subjects by use of the pedobarograph. The function of the toes was assessed by reference to the time they were in contact with the ground and the peak pressures they exerted individually in comparison with other parts of the foot. The toes were in contact for about three-quarters of the stance phase of gait and exerted peak pressures similar to those of the metatarsal region. When the foot was bearing the second peak of total force, the area in contact with the ground (the metatarsal heads and toes) was decreasing.

We studied the effect of a metal tray with an intramedullary stem on the micromotion of the tibial component in total knee arthroplasty. Of 32 uncemented Freeman-Samuelson knee arthroplasties performed in London and Gothenburg, nine had a metal backing and stem added to the tibial component. Micromotion of the tibial components, expressed as migration and inducible displacement, was analysed using roentgen stereophotogrammetric analysis up to two years follow-up. The addition of a metal back and a 110 mm stem to the standard polyethylene component significantly reduced both migration over two years and inducible displacement.

From 1948 to 1980, 93 children and adolescents had fusion in situ for severe spondylolisthesis with a slip of 50% or more, at a mean age of 14.8 years. Of these, 52 girls and 35 boys were reviewed after a mean follow-up of 13.8 years. The mean pre-operative slip was 76% and pain frequency correlated with the severity of the lumbosacral kyphosis but not with that of the slip. Posterior fusion was used in 54, posterolateral in 30 and anterior fusion in three patients. There were no major complications but 16 had re-operations for non-union or root symptoms. At follow-up there were three non-unions. After operation, 19 patients had 10% or more progression of the slip, but 10 showed correction by more than 10% as a result of remodelling. The lumbosacral kyphosis had increased by more than 10 degrees in 45%. Postoperative progression of the slip and of lumbosacral kyphosis was significantly more if the posterior element had been removed. At follow-up 77 patients were subjectively improved, four were unchanged, and one was worse. These results did not correlate with either the degree of the slip, or the angle of lumbosacral kyphosis. Fusion in situ is safe and gives good long-term clinical results. Secondary changes are associated with increased lumbosacral kyphosis, so reduction of this should be considered in severe cases.

Diurnal changes in the loads acting on the spine affect the water content and height of the intervertebral discs. We have reviewed the effects of these changes on spinal mechanics, and their possible clinical significance. Cadaveric lumbar spines subjected to periods of creep loading show a disc height change similar to the physiological change. As a result intervertebral discs bulge more, become stiffer in compression and more flexible in bending. Disc tissue becomes more elastic as its water content falls, and its affinity for water increases. Disc prolapse becomes more difficult. The neural arch and associated ligaments resist an increasing proportion of the compressive and bending stresses acting on the spine. Observations on living people show that these changes are not fully compensated for by modified muscle activity. We conclude that different spinal structures are more heavily loaded at different times of the day. Therefore, the time of onset of symptoms and signs, and any diurnal variation in their severity, may help us understand more about the pathophysiology of low back pain and sciatica.

Discitis after discography is due to bacterial penetration into the intervertebral disc by a contaminated needle and has an incidence of 1% to 4%. We have examined the prophylactic role of cephazolin administered at the time of discography. An experimental study in sheep using radiographic contrast containing Staphylococcus epidermidis showed that either adding the antibiotic to the intradiscal suspension or giving it intravenously 30 minutes before intradiscal inoculation of bacteria prevented any radiographic, macroscopic or histological signs of discitis; all the intervertebral disc cultures were negative. In a prospective clinical study of 127 consecutive patients having lumbar discography, the injected contrast contained cephazolin 1 mg per ml. None of the patients developed clinical or radiographic signs of discitis. We recommend the use of a suitable broad spectrum antibiotic in a single prophylactic dose whenever the intervertebral disc is entered.

The reproduction of symptoms on arthrography of the lumbar facet joint has been accepted as a screening procedure before localised spinal fusion. We studied the histology of 127 facet joints removed at operation from 84 patients, who had previously had facet arthrography. The specificity of the arthrographic results for degenerative joint disease was 75% but their sensitivity was only 59%. This gave a positive predictive value of 85%, but a negative predictive value of only 43%. We conclude that the production of symptoms during facet arthrography is of little value as a screening procedure.

We have conducted a prospective trial of the management of 135 adult patients who had sustained soft-tissue injuries of the neck in vehicle accidents. Early traction and physiotherapy was compared with rest in a collar and unsupervised mobilisation. No benefit from the active treatment could be identified; moulded collars in slight flexion gave the best pain relief and are recommended.

Cadaveric experiments in 10 knees were used to study the strength of two methods of internal fixation for a fractured patella. A modified AO tension band technique was compared with the combination of cerclage wiring and a tension band used at Pyrford. The repairs were stressed to failure; the combination of cerclage and tension band wiring proved to be significantly stronger and is recommended.

From 1982 to 1987 we treated 85 extra-articular comminuted distal third humeral fractures in adults with prefabricated plastic braces. Of these, 15% were open fractures and 18% had initial peripheral nerve injury. On average, the sleeve was applied 12 days after injury and used for 10 weeks. There was 96% union, with no infections. All nerve injuries resolved or were improving at the latest examination. At union there was varus deformity averaging 9 degrees in 81% of patients, but loss of range of movement was minimal and functional results were good.

We reviewed 35 patients who had an amputation following the failure of treatment for severe lower limb trauma. Seven of the amputations were for ischaemia, within one month of injury; 13 were between one month and one year for infection complicating loss of wound cover in un-united fractures; and 15 were later than one year after injury, mainly for infected non-union. The latter group of patients had had an average of 12 operations and 50 months of treatment, including eight months in hospital. We used a new limb injury score based on damage to the individual tissue elements; this indicated that, even in the absence of neurovascular injury, the presence of severe damage to skin, bone and muscle, with wound contamination, particularly in the lower tibia, had a poor prognosis. We therefore recommend, to avoid multiple operations, with prolonged hospitalisation and suffering, that these patients should have early independent review by orthopaedic and plastic surgeons with the aim of establishing an accurate prognosis for the salvage of a useful limb.

The effect of tenotomy and of immobilisation in lengthened and shortened positions on the intramuscular connective tissue of the calf muscles of the rat was studied morphometrically and with a scanning electron microscope. Both tenotomy and immobilisation produced a marked increase in both the endomysial and the perimysial collagen networks, with a simultaneous decrease in intramuscular capillary density. The increase in connective tissue volume was more pronounced and occurred more rapidly in the soleus, which consists mainly of type I, slow-twitch fibres than in the gastrocnemius, which is mainly of type II, fast-twitch fibres. The relative volume of connective tissue increased in parallel with the duration of immobilisation or after tenotomy. There was slightly more increase after immobilisation in a shortened rather than in a lengthened position.

We report 60 benign bone tumours treated by resection and curettage followed by the implantation of calcium hydroxyapatite ceramic (CHA). After follow-up of six to 60 months (average 36), no patient had local recurrence of the tumour or any adverse effects from the implants. In almost all cases radiography showed that the CHA was well-incorporated into the host bone, with new bone formation in and around the CHA. Corrective remodelling of deformed bone and normal fracture healing suggested that there was normal bone turnover in the presence of the CHA. Histology of biopsies from seven patients showed bone ingrowth into the pore structure of CHA in the central zone of some defects by one year after implantation. CHA appears to be a useful substitute for bone graft in the treatment of some benign tumours.

We subjected the proximal tibial growth plates of six-week-old rabbits to either compression or distraction of 1 kg on both legs. On one side the proximal tibial periosteum was divided circumferentially and stripped for 1 cm. After six weeks, growth was measured at both proximal and distal growth plates. Compression inhibited total tibial growth and distraction enhanced it. The compressed growth plate grew less and the distracted growth plate grew more, but there was a reciprocal change at the other end of the bone. Periosteal division enhanced growth at the adjacent growth plate but inhibited it distally; the effect of distraction was enhanced and that of compression reduced. We found reciprocal growth rates at the proximal and distal growth plates. Relatively small amounts of compression or distraction did affect total bone growth. Periosteal division appeared to induce overgrowth at least partly by a mechanical effect; it may be useful as an adjunct to other methods of leg lengthening, though not to epiphyseolysis.

A dose of 48 Gy of X-irradiation given over two to five weeks after grafting caused no significant delay in the rate of healing and only a small and statistically non-significant decrease in the torsional strength of the graft-bone junction of either vascularised or non-vascularised bone grafts of the tibiae of rabbits. Healing was faster and the union between the graft and adjacent bone developed torsional strength significantly more rapidly with vascularised than with non-vascularised grafts. These findings suggest that postoperative radiotherapy is unlikely to have a significantly deleterious effect on the healing of bone grafts used to repair defects produced by excision of malignant bone tumours.

We report a hitherto undescribed type of peripheral nerve lesion in which pressure results in mechanical demyelinisation of a length of nerve with interruption of conduction. On release of the pressure, early recovery may follow the return of the myelin insulation.

Coracoid impingement results from encroachment on the coracohumeral space, presenting as anterior shoulder pain and clicking, particularly in forward flexion, medial rotation, and adduction. In eight shoulders in seven patients, coracohumeral decompression by excision of the lateral 1.5 cm of the coracoid with re-attachment of the conjoined tendon gave pain relief in all, and complete relief in six. This procedure is described and recommended.