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.

Nine cases of acetabular erosion following insertion of the Monk "hard top" hip prosthesis for subcapital fractures are presented. All of these patients had significant symptoms and represented 5% of the total group. In our experience acetabular erosion has proved to be a significant complication of the Monk "hard top" prosthesis.

Sixty-three knees with chronic ligamentous instability treated with flexible carbon fibre are reviewed. Assessment was by pre-operative and postoperative grading of function in work and sport, together with a subjective evaluation of the result based on stability. Fifteen knees had collateral repairs, seven had cruciate repairs and 41 had combined collateral and cruciate repairs. Overall, 71% of knees showed improvement in function and 67% had good or excellent results subjectively. Clinical examination did not correlate well with the patient's evaluation of the result. Nineteen unselected cases with intra-articular (cruciate) carbon fibre had arthroscopies. Infiltration of collagen tissues into the cruciate replacement was a slower process than at the extra-articular (collateral) site. There was no clinical or macroscopic evidence of synovitis but microscopically there was evidence of synovial irritation.