KY Chiu, TP Ng, WM Tang, HC Cheng, TSL Hung, PYT Tse, PS Ko
Department of Orthopaedic Surgery, Queen Mary Hospital, Pokfulam, Hong Kong

OBJECTIVE. 39 sets of preoperative hip X-rays were studied to find out whether Chinese patients need revision femoral components with a different shape and size from western patients.

METHODS. From July 1998 to June 2001, the pre-revision X-rays of 39 revision total hip replacements among 38 Chinese patients (21 men and 17 women) were studied. The component size that produced the best distal canal-filling in the anteroposterior X-ray was determined by using templates of 200-mm femoral components used commonly for Caucasian patients.

RESULTS. The diameter of the component needed was 13.5 mm or less in 54% of cases, compared with only 17% for Caucasian patients as reported in the literature (p<0.01). When lateral templates of the corresponding size were put over the lateral X rays, the anterior cortex of the 200-mm straight stem was shown to have thinned by 2.0 mm or more in 36% of hips; for 200-mm bowed stem, there was thinning of the anterior cortex by 2.0 mm or more in only 5% of hips (p<0.01).

CONCLUSION. Chinese patients are likely to need smaller femoral components than Caucasian patients, and may benefit from bowed-stem components in femoral revision.

Key words: arthroplasty; replacement, hip; Chinese