Attempts to eliminate congenital dislocation of the hip by detecting it early have not been completely successful. It is not known why some infants, checked by competent examiners, still appear late with dislocations. The usual explanations of a mistake by the examiner, or of spontaneous dislocation of a hip that was stable at birth, do not explain why some centres succeed while others fail, or why good examiners may become less effective with experience. The explanation suggested is that the examination itself could be responsible and may actually cause a hip to become unstable.

We investigated the reproducibility of the various radiological methods of assessment of hip dysplasia by making 474 assessments of hips and quantifying the inter-observer and intra-observer variation. There was a wide range of variability between the readings made by different observers and by one observer on two occasions. A measurement of acetabular index has to be given a range of +/- 6 degrees in order to be 95% confident of including the true measurement. We found the most helpful measurements to be the acetabular index, up to the age of eight years; the centre-edge angle, over the age of five years; and Smith's c/b ratio and neck-shaft angle. We feel, however, that the change in value over a series of radiographs in the same child is much more valuable. Single readings of all the radiological measurements investigated in this study were unreliable.

Of 4,617 babies born in Coventry in 1986, a total of 448 (9.7%) had either clinical abnormality of the hip or at risk factors for CDH. All were examined by ultrasound, but only 17 required treatment (3.7 per 1,000); in five of these no clinical abnormality had been detected. An additional 81 babies had ultrasound abnormalities but did not require treatment, despite the fact that ultrasound at first showed major hip displacement in 17 of them. Three late cases of CDH have presented among the babies born in 1986, but not examined by ultrasound. This incidence of late CDH is unchanged compared with the previous nine years, although ultrasound had detected covert displacement in a number of hips.

We reviewed 13 children with partial growth plate arrest who had been treated by epiphyseolysis. Eight were followed to skeletal maturity and five for at least four years. In three cases the affected limb was restored to normal and in five the operation was successful in improving angular deformity and leg length discrepancy such that further surgery was not necessary. In the five failures, angular deformity had progressed or limb length discrepancy had increased. There were no significant complications and the procedure did not prevent subsequent osteotomy or limb length equalisation. Epiphyseolysis was most effective for small bars and those affecting only the central area of the plate.

Ten patients with Charcot-Marie-Tooth disease have been reviewed at an average of 14 years after soft tissue procedures to correct foot deformities. No patient has so far required triple arthrodesis and the overall results as regards function, appearance and symptoms are satisfactory in all patients. It is concluded that soft tissue procedures can certainly postpone the need for triple arthrodesis and in many cases may obviate it altogether.

Dynamic hyperextension of the big toe and supination of the forefoot may occur in the swing phase of walking in children with various neurological disorders. Symptoms arising from this have been successfully corrected in 13 feet of 11 children by transfer of extensor hallucis longus to the insertion of peroneus brevis.

We reviewed 36 cases of forearm deformity caused by multiple osteochondromas in 30 patients and classified them into three types: Type I showed a combination of ulnar shortening and bowing of the radius secondary to osteochondromas of the distal ulna (22 forearms). Type II showed dislocation of the radial head, either with osteochondromas of the proximal radius (Type IIa, two forearms) or secondary to more distal involvement (Type IIb, five forearms). Type III had relative radial shortening due to osteochrondromas at the distal radius (seven forearms). Operations were performed on 16 forearms in 13 patients, with 92% of satisfactory results. For Type I deformity, excision of osteochondromas, immediate ulnar lengthening and corrective osteotomy of the radius are recommended. For Type IIa, excision of the radial head is necessary, and for Type IIb, we advise gradual lengthening of the ulna using an external fixator. Excision of osteochondromas alone gave good results in Type III deformity. Our classification gives a reliable indication of the prognosis and is a guide to the choice of surgical treatment.

We report five examples of physeal widening in four children with myelomeningocele. In all cases there was rapid clinical resolution with the use of the patients' normal orthoses and minor limitation of activity, and there was no evidence of early epiphyseal closure or growth disturbance. We suggest that recognition of the pathological process before fracture occurred may explain the rapid return to normal.

In 15 consecutive patients with slipped capital femoral epiphysis we recorded height, weight and skeletal maturity. Sexual maturity was assessed clinically and biochemically, and Harris's hypothesis that there is an increased ratio of serum growth hormone to oestrogen was tested in comparison with 15 age and sex matched controls. We found no difference in skeletal or sexual maturity between the groups, or any overt endocrine abnormality in the patients. However almost half the patients with slipped epiphysis were over the 90th weight percentile, suggesting that mechanical factors such as obesity are more important aetiologically than endocrine abnormalities.

We have tested the porosity and fatigue life of five commonly used bone cements: Simplex P, LVC, Zimmer regular, CMW and Palacos R. Tests were conducted with and without centrifugation and with the monomer at room temperature and, except for LVC, at 0 degrees C. We found that the fatigue life of different specimens varied by a factor of nearly 100. It did not depend on porosity alone, but was more influenced by the basic composition of the cement. Simplex P when mixed with monomer at 0 degrees C and centrifuged for 60 seconds had the highest fatigue life and was still sufficiently liquid to use easily.

We have studied the role of computerised axial tomography in the assessment of the acetabulum before an uncemented Mittelmeier arthroplasty was performed in 20 patients. In the absence of gross anatomical abnormality, computerised tomography did not provide additional information, but in eight patients it was useful in determining adequacy of acetabular depth, anterior acetabular cover, and thickness of the anterior and posterior walls. In these patients, the CT scans provided information which was not available from plain radiographs and greatly assisted in pre-operative planning.

Electromyographic and clinical studies were performed on patients undergoing total hip replacement by the modified direct lateral (29 hips), the direct lateral (29 hips) and the posterior approaches (21 hips). Assessments were made three months after operation. The Trendelenburg test was positive (Grade II) in eight cases operated upon by the direct lateral route, but in only one of each of the other two groups. Denervation occurred in only five of the 28 hips with abductor weakness without statistical difference between the groups. In the modified direct lateral group, radiological evidence of union of the trochanteric sliver was associated with significantly better abductor function than in those with malunion or non-union.

We have reviewed nine patients with Parkinson's disease who had 12 primary total knee arthroplasties and one revision. Deformities were corrected by conventional techniques and semi-constrained resurfacing arthroplasties were used. Follow-up ranged from two to eight years (average 4.3 years). Nine of the 12 primary arthroplasties were rated as excellent by the Hospital for Special Surgery knee score system, and three were rated as good. Contrary to previous reports, we feel that total knee arthroplasty performed on patients with Parkinson's disease, is a highly satisfactory procedure, alleviating knee pain and improving function.

The effect of storage at sub-zero temperatures and subsequent thawing was investigated in dissected muscles, tendons, limbs and spines. Freezing caused a noticeable shortening of muscles which when thawed could easily be elongated; the same effects, though less pronounced, were observed with tendons. During freezing, myotomy or tenotomy led to the development of a striking deformity owing to unopposed shortening of the opposing muscles. After thawing, all frozen specimens containing muscles and joints showed an increased range of passive movements, easily demonstrable by mild tensile forces.

Four en-bloc resections for malignant tumours of the hip, the peri-acetabular region and the iliac wing were reconstructed using an irradiated hemipelvic allograft together with a total hip prosthesis. Technical aspects include the use of an anterior Enneking approach which excises the previous biopsy site, division and re-attachment of the iliac crest and fixation of the prosthesis using a modified acetabular cup and three polypropylene artificial ligaments to increase the stability of the joint. Weight-bearing was allowed at three months. The oncological and clinical results were satisfactory after a mean follow-up of 19 months, with walking distances of 500 metres to two kilometres without pain.

Twelve patients were operated upon after unsuccessful conservative treatment for complete dislocation of the sternoclavicular joint. Three methods were used; stabilisation using fascial loops, reconstruction with a tendon graft, and resection of the sternal end of the clavicle. The results were good in only four patients, three treated with a tendon graft and one by fascial loops. Another four patients had fair results, but all four treated by resection of the medial end of the clavicle had poor results, with pain and weakness of the upper extremity. In our opinion resection of the sternal end of the clavicle should not be used in old traumatic dislocation.

We present a method for the reducing a displaced radial head in children, by rotating the forearm while pressing over the displaced fragment. This has been successful in a series of 10 cases.

We report a prospective, randomised, controlled trial of 50 severely displaced comminuted Colles' fractures treated by either external fixation or manipulation and plaster. Each patient was assessed radiographically throughout treatment, and functionally by an independent observer at three and six months. The functional result correlated with the anatomical result, which was significantly better in patients treated by external fixation. This resulted in significantly improved function especially in young patients, and also a lower complication rate. We recommend the use of external fixation for young patients with comminuted displaced Colles' fractures unless manipulation and plaster show excellent reduction.

In an attempt to repair articular cartilage, allograft articular chondrocytes embedded in collagen gel, were transplanted into full-thickness defects in rabbit articular cartilage. Twenty-four weeks after the transplantation, the defects were filled with hyaline cartilage, specifically synthesising Type II collagen. These chondrocytes were autoradiographically proven to have originated from the transplanted grafts. Assessed histologically the success rate was about 80%, a marked improvement over the results reported in previous studies on chondrocyte transplantation without collagen gel. By contrast, the defects without chondrocyte transplantation healed with fibrocartilage. Immunological enhancement induced by transplanted allogenic chondrocytes or collagen was not significant at eight weeks after treatment, so far as shown by both direct and indirect blastformation reactions. Thus, allogenic transplantation of isolated chondrocytes embedded in collagen gel appears to be one of the most promising methods for the restoration of articular cartilage.

The anterior exposure of the upper thoracic spine using standard methods is often difficult and limited. We report our experience using a technique described by Sundaresan et al. (1984) in which the medial portion of one clavicle and part of the manubrium sterni are excised. In 10 cases we found this to be a useful and safe procedure.

Vitamin D metabolite levels were measured in serum and bone samples obtained from 27 patients undergoing elective bony procedures and from 28 patients operated on after a fracture. Serum 25 hydroxyvitamin D3 (25-OH-D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) did not differ significantly between the elective and fracture patients, but serum 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) was significantly reduced in the fracture patients. Very little 25-OH-D3 was found in bone, although it was the major vitamin D metabolite in serum (90%). In elective patients bone levels of 24,25(OH)2D3 and 1,25(OH)2D3 were similar to those in serum; however, in bone from around pertrochanteric fractures, but not from subcapital or patellar fractures, the concentrations of these compounds were considerably increased. These findings may shed light on the mechanism of callus formation and on the role of vitamin D metabolites in bone healing.

The straight leg raising test and the femoral nerve stretch test exert traction on the sciatic and femoral nerve, and the lumbosacral plexus and roots. In 40 patients with a suspected L4/5 disc protrusion, ipsilateral sciatica was induced by the femoral nerve stretch test. We believe that this is a pathognomonic sign of a lateral protrusion at L4/5 level.

We report three cases of atlanto-axial rotatory fixation in adults. Early diagnosis was made by clinical tests showing restricted head rotation in maximal neck flexion and asymmetry of the transverse processes of the atlas, confirmed by cineradiography. Early treatment by traction may obviate long-term problems of torticollis and instability.

Sublaminar wiring provides strong and effective fixation of the scoliotic or unstable spine, but its long-term effects on the spinal canal remain unknown. An animal model was developed to observe these effects on the growth and development of the immature spine over a two-year period. Laminar overgrowth occurred both longitudinally to produce a kyphoscoliosis and in the transverse plane to cause significant laminar thickening and growth into the spinal canal. However, the cross-sectional area of the spinal canal was not significantly compromised.

The axis of the talo-crural joint was analysed by roentgen stereophotogrammetry in eight healthy volunteers. Examinations were performed at 10 degrees increments of flexion and pronation/supination of the foot as well as medial and lateral rotation of the leg. Results indicate that the talo-crural joint axis changes continuously throughout the range of movement. In dorsiflexion it tended to be oblique downward and laterally. In rotation of the leg, the axis took varying inclinations between horizontal and vertical. All axes in each subject lay close to the midpoint of a line between the tips of the malleoli. Our study indicates that the talo-crural joint axis may alter considerably during the arc of motion and differ significantly between individuals. This prompts caution in the use of hinge axes in orthoses and prostheses for the ankle.

The microvascular anatomy of the calcaneal tendon was investigated in cadaver tendons by injection of barium sulphate and indian ink and a quantitative study of intratendinous blood supply was made, using a computer-assisted image analysis system. There was a reduction in both the number and the mean relative area of vessels in the mid-section of the tendon. This area of reduced vascularity may be of significance in the pathogenesis of rupture.

We analysed the complication rate in 140 below-knee amputations in relation to surgical technique and the presence of diabetes. In all cases, the skin perfusion pressure was measured below the knee before operation to provide an objective evaluation of the microcirculation. In diabetic patients we found a significantly higher complication rate after using a long posterior flap than after equal sagittal flaps. No such difference could be demonstrated in non-diabetic patients. We suggest that the higher incidence of atherosclerotic lesions in the three major arteries below the knee in diabetic patients may account for the difference. We recommend the use of the sagittal technique for below-knee amputation in diabetic patients.

Stress fractures of the tarsal navicular do not heal predictably with conservative treatment, so we recommend operation if the fracture remains symptomatic, and radiographs show wide separation of a complete fracture, extension of an incomplete fracture, delayed healing, or a medullary cyst. An autologous bone graft is inserted after en-bloc resection of the fracture surfaces. It is important that the fracture is fully exposed to its distal limits before the graft is inserted. We have grafted 19 fractures in 18 patients. Six fractures were complete, 12 incomplete and one had a residual medullary cyst. Of the 15 patients with adequate follow-up, 12 had been able to return to a pre-injury level of activity by five to 12 months.

Twenty-three of 46 patients, aged 56 to 95 years, with fracture of the femoral neck (FNF) completed the first trial of 10 months treatment with oral sodium fluoride 60 mg and calcium 1800 mg on alternate days and 1 micrograms of vitamin D1 daily. Pre-treatment and post-treatment biopsy specimens and microradiographs of the iliac crest and metacarpal and spinal radiographs were evaluated together with biopsy material from seven untreated age-matched controls with FNF. In 17 patients the treatment improved the amount and quality of trabecular bone. Cortical thickness increased in nine patients and there were no losses of amount or mineralisation. The treatment was well tolerated by most patients and there were no major side-effects or signs of bone demineralisation. The study also revealed an unexpected rapid post-fracture deterioration of bone tissue in untreated FNF patients; thus there is an increased risk of further fractures which calls for the use of an effective treatment to increase bone mass.

We reviewed seven patients with coronal fractures of the lateral femoral condyle and studied the mechanism of injury and the radiological features. The influence of soft tissue attachments on the displacement and the blood supply were investigated by clinical and cadaveric studies. All three fractures which were initially undisplaced lost position early during conservative management. Internal fixation gave good results at review, and is recommended to avoid the risk of malunion and possible secondary osteoarthritis.

We reviewed 41 knees after arthroscopic lateral release for recurrent dislocation of the patella at a mean follow-up of four years, and graded the results according to the criteria of Crosby and Insall (1976). There were no dislocations after operation in 28 knees (68%); the less satisfactory results were in patients with subluxation of the patella on extension of the knee and those with generalised ligamentous laxity. There were no complications. A characteristic and previously unreported lesion of the patellar surface was seen in eight of the 41 knees. The results of lateral release are better than those reported for other techniques. This treatment, by either open or arthroscopic methods, is recommended.

Sixty patients underwent arthroscopy of the knee as day cases using a local anaesthetic technique. This provided satisfactory operating conditions and high patient acceptability.

We examined the menisci in 47 patients at the time of anterior cruciate ligament reconstruction. Twenty-one patients had abnormal menisci at a mean of 34 months after injury, but there was no difference between the Lysholm scores of patients with intact or damaged menisci. Eleven patients had a new meniscal injury between reconstruction and review at a mean of six years later; only 15 patients had both menisci intact nine years after injury. If pivot shift had been cured, the incidence of meniscal injury was reduced, but remained higher than normal. If pivot shift returned after reconstruction there was a significantly higher incidence of meniscal injury. Meniscal lesions appear to be the result of instability and not the cause.

Entrapment of the superficial peroneal nerve was treated in 24 legs of 21 patients by fasciotomy and neurolysis; 19 of the patients were reviewed after a mean period of 37 months. Nine were satisfied with the result, another six were improved but not satisfied because of residual limitation of athletic activity, three were unchanged and one was worse. Conduction velocity in the superficial peroneal nerve had increased after operation, but the change was not significant. In five patients the nerve had an anomalous course and in 11 there were fascial defects over the lateral compartment. Chronic lateral compartment syndrome is an unusual cause of nerve entrapment. Operative decompression produces cure or improvement in three-quarters of the cases, but is less effective in athletes.