The use of trochanteric osteotomy in lateral approach to the hip joint is a fundamental part of Charnley's low-friction arthroplasty. Its use allows adequate exposure and easy orientation of the hip. Reattachment using a single transverse and double vertical wires was evaluated in 500 consecutive hip arthroplasties. Of 500 patients, 466 (93.2%) showed complete bony union of their trochanteric osteotomy at three months. A further 20 (4%) patients united by 12 months, giving a union rate of 97.2%; 34 (6.8%) patients who showed incomplete or defective union at three months. There were five dislocations. Only one patient required removal of the wires, for bursitis. The patients with defective bony union had a relatively high rate of wire breakage at three months. Despite a 1.8% complete detachment and 1% fibrous union, the transtrochanteric approach allows easy access without fear of shaft fracture in very difficult cases, with surprisingly little ill effect or loss of function even in those failing to reunite.