Recurrent dislocation of peroneal tendons is uncommon and there are few reports of the long-term results after repair. The Singapore operation, first described in 1985, is an anatomical repair based on the Bankart-like lesion seen in the superior peroneal retinaculum.

We reviewed 21 patients after a mean follow-up of 9.3 years, and found no recurrence. Eighteen had good functional results and had returned to their previous levels of vocational and sports activities. The three fair results were due to painful scars or neuromas.

We reviewed 27 patients who had supracondylar closing wedge osteotomy for cubitus varus. There were 10 excellent and 12 good results. However, of these 22 patients, 14 had a significant bony prominence over the lateral condylar region caused by lateral displacement of the elbow when closing the osteotomy. This prominence was less obvious in patients who had their osteotomy at a young age, but worse after operations near or after skeletal maturity. This difference appeared to be due to remodelling.

Four different experiments were performed to study the healing of a large, non-vascularised, diaphyseal, bone segment in adult cats. In the first experiment, a 4 cm segment of tibia with its periosteum was excised and replaced in its bed. The other experiments were similar, except that in the second, the periosteum of the segment was removed, in the third its medullary canal was blocked with a Silastic rod, and in the last group the segment was isolated from its muscle bed by a Silastic sheet. The reparative processes were quantified by estimating the resorption index, the cortical new bone formation index, the callus encasement index, and the osteocyte count. Bone resorption and apposition occurred in the segment even when the periosteum was absent or the medullary canal was blocked, with osseous union at both ends by eight to 12 weeks, provided the segment was not isolated from its muscle bed. Thus, the muscle bed played a significant role in these reparative processes.

The role of atmospheric pressure in providing static stability of the shoulder was studied experimentally in 24 cadaveric shoulders. Atmospheric air was allowed to enter the joint after puncturing the capsule. Three types of experiment were performed: in the first, the capsule was punctured after sequential division of the muscles; in the second, atmospheric air was let in by percutaneous puncture of of the capsule without dividing the muscles; and in the third, air was first let into the joint by percutaneous puncture of the capsule and then the muscles of the shoulder were divided. It was found that the intact shoulder subluxated after percutaneous puncture even without division of the overlying muscles or the capsule. Our findings suggest that negative pressure and muscle tone are the main static stabilisers of the shoulder, rather than the joint capsule.

A lesion similar to that described by Bankart in recurrent dislocation of the shoulder was seen in seven patients with recurrent dislocation of the peroneal tendons. Detachment of the periosteum had resulted in the formation of a false pouch on the surface of the lower end of the fibula; into this pouch the peroneal tendons could easily dislocate. Reattachment of the periosteum to drill holes in the fibula prevented dislocation, and this anatomical method of repair is described. This lesion is one of the causes of recurrent dislocation of the peroneal tendons.

The joint surfaces of 60 hips obtained from the cadavers of elderly Asians were studied to determine the incidence, the grade and the distribution of both non-progressive (age-related) and progressive degenerative changes. It was observed that in the Asian population of 40 to 90 years of age, non-progressive changes were common, being seen in 66% of the acetabular specimens and 50% of the femoral heads. Only one specimen of the 60 showed unexplained progressive degenerative change. We conclude that primary osteoarthritis of the hip is rare in Asians.

Moire topography was added to school scoliosis screening in Singapore in 1982. The results from 1342 topographs, assessed in isolation, were used to study the accuracy of the method in predicting the radiographic location and magnitude of scoliotic curves. Accuracy in identifying the site of the curve was 68% in the thoracic spine, 54% in the thoracolumbar spine, and 15% in the lumbar region. There were 12.7% false-positive results and 4.3% false negatives. Of patients with a deviation of one moire fringe, 76.5% had a curve of 15 degrees or less; of those with a deviation of four moire fringes, 69% had a curve greater than 26 degrees. The prediction of the Cobb angle was less accurate when there was a deviation of two or three fringes. It is suggested that moire topography as a screening device should be reserved for use in the second tier of screening, since the forward-bending test is an effective and cheap method for the first tier of a mass school-screening programme.

Routine examination for spinal deformity as part of a school health screening programme was introduced in Singapore in 1981. The three different ethnic groups included in the study provided figures for the prevalence of idiopathic scoliosis in an Asian population. A three-tier system of examination was used and a total of 110744 children in three age groups were studied. In those aged 6 to 7 years the prevalence was 0.12%. The prevalence in those aged 11 to 12 years was 1.7% for girls and 0.4% for boys, a ratio of 3.2 to 1. In girls aged 16 to 17 years the prevalence was 3.1%. In the latter two age groups there was a significantly higher prevalence in Chinese girls as compared with Malay and Indian girls. The optimal age for school screening seemed to be 11 to 12 years, but repeated examinations may be worthwhile.

This experiment demonstrates that infiltration of hydrocortisone into rabbit calcaneal tendons has a direct effect on the tendon, producing necrosis of collagen at the site of injection. The repair of the lesion so produced is incomplete even after eight weeks, and is often complicated by dystrophic calcification. Similar morphological changes may account for spontaneous rupture of tendons in patients receiving steroid infiltration.