Abstract

Lister’s tubercle, a bony prominence of the dorsal radius comprising radial and ulnar peaks, forms a groove for the extensor pollicis longus (EPL) tendon. It is a surgical landmark and important in imaging, as it can obscure lateral X-rays of screws penetrating the EPL groove in volar plating of wrist fractures. This novel ultrasound study analyses the height of the radial peak above the EPL groove and the ulnar peak, distance of radial and ulnar peaks from the ulnar notch and EPL tendon angulation. Approval was obtained from the Cambridge Human Biology Research Ethics Committee for scanning of 30 volunteers (18 females: 12 males). Measurements were analysed for symmetry, sex and ancestral differences. Regarding height of the radial peak above the EPL groove and ulnar peak, South Asians showed lower values compared to White and East Asian populations. In males the radial peak was further from the ulnar notch, accounted partly by sex differences in radial width. Correlations existed between distance of the radial peak from the ulnar notch and radial width (p<0.0001, r=0.7104), and distance of the ulnar peak from the ulnar notch and radial width (p=0.0004, r=0.6102). These findings will improve accuracy in procedures performed at the wrist.