A series of 135 knee arthroscopies has been reviewed to determine the accuracy of detection of meniscal lesions. Arthroscopy and double-contrast arthrography achieved similar accuracy (84 per cent and 86 per cent) in the diagnostically more difficult knees of the series. The combined accuracy of both examinations was 98 per cent. Arthroscopic difficulty in seeing the posterior third of the medial meniscus, and consequently tears in this region, is emphasised and discussed. Arthroscopy and arthrography are complementary in the diagnosis of difficult meniscal problems.

Of 250 patients scheduled for meniscectomy 50 had symptoms which subsided and operation could be deferred; of the remaining 200 only 73 per cent were found to have a significant tear. It is shown that the risks of removing a normal meniscus far exceed those of leaving a tear in the posterior third. Statistical analysis of clinical features revealed no reliable diagnostic pattern.

Complete fractures through bone affected by Paget's disease may not deserve their innocent reputation. This retrospective study of 182 such femoral fractures, the largest reported series to date, was carried out to discover the behaviour of these fractures in the absence of specific therapy for the Paget's disease. Most previous series have concluded that healing is uneventful but the findings in these patients from the West Midlands do not bear this out. After exclusion of the early deaths, the overall incidence of non-union was 40 per cent, the main problems being posed by the subtrochanteric fractures and those of the upper shaft. Although callus may be abundant, it may itself be involved in the disease process and is not a reliable sign of union. Based on these observations, suggestions for management in the different regions of the femur are made.

Two cases of bilateral slipping of the upper femoral epiphysis in boys with end-stage renal failure due to megacystis and mega-ureter with severe renal osteodystrophy are reported. In one patient the lesion emerged after a dystonic reaction to drugs and in the other after bilateral nephro-ureterectomy. Neither showed marked elevation of growth hormone levels, but both had evidence of renal rickets with severe secondary hyperparathyroidism. Both had a satisfactory response to bilateral internal fixation. The complication should be borne in mind in all young patients with renal osteodystrophy.

Numerous intravascular bony spicules were found at necropsy in both lungs of an 84-year-old patient who had undergone total hip replacements three and 10 months before death. It is suggested that acetabular grindings enter the damaged venous system at operation and are filtered out by the lungs.

Of 193 children with Perthes' disease at the Texas Scottish Rite Hospital for Cripppled Children, 24 were found to have only minimal changes. The cases were grouped relative to the area of the femoral head involved, with 10 involving the anterior portion, seven the posteromedial, three the lateral, and four the central portion. Almost all hips lost some height as measured by the epiphysial index but all had good results by the Mose criteria irrespective of treatment. The anterior lesion is the same as that described by Catterall as Group 1. The three additional groups have a similar benign natural history but distinct radiographic features. The need for early recognition of these patterns is emphasised if unnecessary treatment is to be avoided. Possible correlations of these lesions with the segmental blood supply of the femoral head are proposed and an hypothesis relating the Catterall classifications to the blood supply is put forward.

The radiographs of 153 children suffering from Perthes' disease of one hip were studied to examine the bony outline of the femoral capital epiphysis in the unaffected hip. In 48.4 per cent of patients irregularity of the surface, flattening or dimpling, were noted; in the majority of instances (37.2 per cent) these changes were present in the initial anteroposterior radiograph. By contrast, these changes were present in only 10.4 per cent of a control series of 153 children in whom intravenous urography was being performed, these children being matched for age and sex with the children with Perthes' disease. A second unmatched control series of 49 children whose pelves were being radiographed after injury showed a 6.1 per cent incidence of contour irregularities in 98 femoral capital epiphyses. In the patients with Perthes' disease and in the control series obtained at urography the incidence of changes was inversely related to age. The possible cause and significance of contour irregularities in normal children and in those with Perthes' disease is disscussed.

The results of 757 intertorchanteric osteotomies for osteoarthritis of the hip carried out between 1958 and 1970 were reviewed. After osteotomy the joint space in two thirds of the hips was increased and a similar proportion experienced relief of pain lasting at least five years. However, the effect of the osteotomy declined after some ten years; only a quarter of the hips had a lasting "good result" as defined in this investigation. The best results were obtained in active patients under 70 years of age with unilateral hip disease in which a fair range of movement had been preserved despite some shortening and where the radiographs showed loss of joint space with a break in Shenton's line. In this study a displaced osteotomy fixed with a spline emerged as the most successful surgical technique.

Two patients with osteochondritis dissecans of the hip were operated on and their case histories are presented. The relatively large foci were situated on the weight-bearing surface of the joint and the fragments were fixed using transplants of cortical bone. In both cases the focus healed, and the symptoms were relieved. At follow-up six and nine years later respectively, the clinical results were good and no signs of osteoarthritis had as yet developed.

A case of early closure of the triradiate cartilage, probably secondary to neonatal septic arthritis of the right hip, is reported. Tomograms of the hip showed the triradiate cartilage closed posteriorly, with the anterior portion still open. These findings were confirmed at operation. An arthrogram and a CT scan of the right hip showed subluxation of the femoral head. This unique complication, after an episode of septic arthritis of the hip, has not before been reported in the literature.

We have reviewed the results of operations to stabilise the paralytic hip and to correct and stabilise the deformed spine of children with myelomeningocele. Despite a high complication rate the spinal operations were frequently successful. The hip operations were less satisfactory, with stabilisation of the hip eventually achieved in 69 per cent of the patients and improved walking in only 27 per cent. We do not recommend that such operations be undertaken on the hips of children with a level of paralysis at L3 or above. If stabilisation is indicated multiple combined procedures produce the best result.

Two hundred and fifty cases of myelodysplasia were reviewed in relation to spinal deformity. Approximately half of the children had, or were expected to develop, curves severe enough to need operations and only 10 per cent maintained completely undeformed spines. The most frequent deformity was scoliosis which could be subdivided into congenital and developmental types. The latter was of mixed aetiology, neuromuscular imbalance and asymmetry of the neural arch both contributing, while in some cases no causative factors could be identified. The best early indicator that developmental scoliosis was likely to appear was a high segmental level of both the neurological deficit and the neural arch defect. Deformity was very unlikely to start after the age of nine years.

The factors during and after operation which influence the development of a solid and stable posterior spinal fusion have been evaluated in 406 patients with scoliosis. The patients were managed in three different ways and all pseudarthroses were accurately detected by exploring the spines six months after the attempted fusion. The incidence of pseudarthroses was significantly lowered from 25 per cent in Group I to 3.8 per cent in Group III by the application of Harrington instrumentation and the use of large amounts of autogenous iliac bone grafts in addition to an interfacetal fusion. Early mobilisation 7 to 10 days after operation and a return to normal activities in a well-moulded underarm plaster jacket did not have a detrimental effect on the development of the fusion or the early maintenance of correction. Those spines with supplementary bone grafts stabilised more rapidly and had better maintenance of correction with only minimal loss after removal of all external support at 10 months.

Scintigraphy using technetium-labelled methylene diphosphonate was performed on 110 scoliotic patients six months after an attempted fusion and the findings compared with those at exploration to detect the possible sites of pseudarthroses. The majority of patients (65 per cent) had a uniform uptake of isotope over the fused area and all but one had a solid fusion. A second group (35 per cent) had a more patchy uptake and eight of the nine patients with pseudarthroses were in this group. Pseudarthroses were detected as localised areas of increased uptake but there were also a number of false positives and scans that were difficult to interpret due to continuing new bone formation in immature fusions. In those scans performed after one year the pseudarthroses which had been missed were seen more clearly in contrast to the diminished generalised activity in the fused area.

The shallow lateral recesses of the trefoil shape of the lumbar spinal canal have been implicated in the production of the spinal stenosis syndrome. In the present study, 485 skeletons of South African Blacks and Whites were examined in order to establish the incidence and possible genesis of the trefoil configuration. The overall incidence was 14 per cent, with little variation between the sexes or races. The incidence was not related to increasing age, measured stenosis of the spinal canal or osteophytosis. Of 74 trefoil-shaped vertebrae, 68 (92 per cent) were found at the fifth lumbar level. It is suggested that the trefoil configuration is a common non-pathological condition, usually of the fifth lumbar vertebral canal, and is probably a developmental variation of normal anatomy.

Cross-sectional studies of the lumbar spinal canal were performed by computerised tomography in asymptomatic subjects and in patients with myelographic and clinical findings suggestive of lumbar stenosis. In most cases stenosis was found to be developmental or combined in nature. Computerised tomography is a useful adjunct to myelography in the evaluation of lumbar stenosis as it enables an accurate assessment to be made of the type, degree and extent of narrowing of the vertebral canal.

This is a review of 77 partial replacement and interposition arthroplasties in which Silastic implants were used. The operations were carried out between 1971 and 1977 on the metatarsophalangeal joints of the great toes of 62 patients. Twenty-six of the operations were for painful hallux rigidus and 51 for hallux valgus. The patients were reviewed 12 to 92 months after operation, the average follow-up being 60 months. The analysis of results indicated that while the procedure may be suitable for hallux rigidus its use for hallux valgus is not fully satisfactory in the long run.

At re-examination of all osteosarcomata recorded in the Swedish Cancer Registry during the years 1958 to 1968, 11 cases of parosteal osteosarcoma were found. No case of so-called periosteal osteosarcoma was identified. The tumours constituted 1.6 per cent of all proved primary malignant bone tumours. The ages of the 11 patients (six women and five men) ranged from 17 to 62 years (average 33 years). The clinical and histopathological findings of this study and of those collected from a review of the literature suggest the occurrence of two different types of parosteal osteosarcoma: the predominant type is originally benign but has a definite malignant potential, causing metastases after long symptom-free intervals; the other type is highly malignant from the beginning. Primary amputation is recommended for the latter category of tumours, and compartmental, radical en bloc resection followed by regular review is recommended for the former.

Fifty-five cases of osteosarcoma of the extremities were treated between 1972 and 1976 by combined surgery and chemotherapy (vincristine, adriamycin and methotrexate in medium doses) for 18 months. The follow-up ranges from 30 to 80 months (mean = 48 months). Twenty-six patients remained free from any evidence of disease, two had local recurrences but no metastases and 27 had metastases (four of these also had local recurrences). In 12 patients, the metastases appeared after the end of chemotherapy. Both metastases and local recurrences were more frequent in patients who had segmental bone resection (7/8) than in those treated by more radical surgery (22/47). Comparison with an "historical" group (94 osteosarcoma patients treated by operation alone in our Institute between 1960 and 1971) showed that the percentage of patients free from evidence of disease was higher in the group who receiving chemotherapy. In addition, the appearance of metastases in this group was delayed (mean = 16 months) as compared with the historical controls (mean = 8 months). On the other hand, after the same kind of operative treatment, the rate of local recurrences and the time of their appearance was almost identical in both groups.

The effect of the environmental temperature on the healing of fractures was assessed in vertebrae of tails of young albino mice. It was found that fractures in animals kept at 33 degrees Celsius healed very rapidly (bony callus by 14 days) while in animals kept in the cold (8 degrees Celsius) fractures were still at the stage of granulation tissue at this time. Controls were at an intermediate stage. This result might have a clinical application.