In comparative studies of various gait patterns of 20 healthy subjects who used a cane, the vertical reaction forces and the passages of the center of force on the foot were measured and recorded by a force recording and analyzing device (Foot-scan system). The results indicated that when a cane was used in the ipsilateral hand, the center of force did not shift significantly compared with normal gait. When a cane was used in the contralateral hand, the center of force shifted medially compared with normal gait. In analysis of the vertical floor reaction force acting on the foot, the most efficient way to use a cane was to control the pacing so that the tip of the cane and the foot touched the ground simultaneously. By doing so, the cane could share as much as 34.3% of force at heel strike, 25.3% at midstance, and 29.7% at toe off of the stance phase of the gait cycle. When prescribing use of a cane for a patient with varus gonarthritis, the patient should be instructed to use the cane in the ipsilateral hand so as not to shift the center of force medially; for a patient with valgus gonarthritis, the cane should be used in the contralateral hand to shift the center of force medially. Patients should be taught to control pacing so that the tip of the cane and the foot touch the ground simultaneously.

We performed curettage and bone grafting of amyloid cysts of the femoral neck in five patients on long-term haemodialysis. All had had hip pain on weight-bearing. The duration of haemodialysis before the operation averaged 15 years and the average age of the patients was 53 years. All the large cystic lesions were located in the anterosuperior quadrant of the femoral neck. At operation, they were found to consist of fibrous tissue containing amyloid deposits. Postoperatively, all five patients had painless hips and the grafts had incorporated into the bone defects.

We retrospectively reviewed 17 hip arthroplasties in 15 patients having haemodialysis for chronic renal failure. The duration of haemodialysis before the operation averaged 8.6 years and the average age of the patients was 61 years. All patients were followed for more than two years (mean 4.6 years). Six arthroplasties in four patients had failed due to loosening, and one of these patients died from undiagnosed infection of both hips at 7.6 years after the operation. General skeletal abnormalities caused by maintenance haemodialysis may explain the high incidence of loosening and it is important to be aware of the danger of postoperative infection. The risk-to-benefit ratio of hip arthroplasty is high in patients on haemodialysis.

We reviewed 29 patients who had developed destructive arthropathy of the spine during long-term haemodialysis. Their mean age when haemodialysis began was 43.8 years; at diagnosis they had been dialysed for an average of 8.6 years. In 26 patients, the lesions were between C4 and C7; in six they were between L4 and S1, three having lesions in both regions. Sixteen patients had had previous surgery for carpal tunnel syndrome. Spinal surgery was performed in nine patients with satisfactory results in only five. We demonstrated beta-2 microglobulin amyloid deposits in the discs and surrounding ligaments in all biopsied cases. The natural history and management of this condition are not yet clear.

The use of standing radiographs to determine correction angles for high tibial osteotomy is not appropriate because the relative angle of the articular surfaces (condylar-plateau angle) in the weight-bearing knee changes after the osteotomy. This may give unpredictable results postoperatively. We found that the condylar-plateau angle in postoperative standing films is very similar to that seen in non-weight-bearing supine views, and suggest that these latter radiographs be used for pre-operative planning. We describe our early results, using a special osteotomy jig, in 140 knees.