A Radiologic Survey Of Morphological Indexes Of Chinese Proximal Tibias

Objective To investigate morphological indexes of Chinese people.in proximal tibias by radiologic measurement, providing parameters in designing of internal fixator for proximal tibias . Methods One hundred and fifty-eight knees of 112 Chinese people living in Shanghai and East China were measured, which included 80 healthy knees and 78 arthritic knees. The ages averaged 56 years, ranging from 20 to 88 years. Everyone was required to take a full-length standing X-ray film of the lower extremity. The hip-knee-ankle angle(HKA), the femorotibial angle(FTA) and the tibial plateau-tibial shaft angle(TP-TSA) were measured on the anteroposterior radiograghs, while the posterior slope angles of medial and lateral tibial plateau(PS) were measured on the lateral radiograghs based on three reference lines: anterior tibial cortex tangent line (Method One), tibial proximal anatomical axis (Method Two) and posterior tibial cortex tangent line (Method Three). Results In healthy Chinese adults, the mean value of the HKA was 177.4°±1.5°; the FTA was 175.5°±2.4°; the TP-TSA 84.6°±2.5°. The mean medial PS was 14.0°±3.0°by Method One, 11.0°±2.7°by Method Two, and 8.0°±2.9°by Method Three. while the mean lateral PS values by the 3 methods were 11.2°±3.1°,8.1°±2.9°,and 5.3°±2.9°respectively. By statistical analysis, the HKA and FTA were significant different between the healthy knees and the arthritic ones. The PS decreased obviously in severe arthritic patients. There was a statistically significant difference between the medial and lateral PS values, no matter which of the measurement methods used. Conclusions The average TP-TSA and PS of tibial plateau in Chinese people are larger than those in the Westerns. The FTA, TP-TSA and PS are very useful indexes both in surgery and clinical research.