Anatomical Measurements of the Distal Clavicle in a Kenyan Population

Abstract

Anatomical measurements of the distal clavicle are important in the design of clavicular implants for fixing clavicular fractures and reconstruction of the coraco-clavicular complex in acromio-clavicular joint dislocations. These measurements show population variations however, little data exists from the African population and none for the Kenyan one. One hundred and eighty unpaired dry adult human clavicles were obtained from the Department of Human Anatomy, University of Nairobi. The length of clavicle and distance of conoid and trapezoid tuberosities from the distal end were measured using a ruler. The superoinferior thickness of the distal end was measured using a vernier caliper. The mean clavicle length was  148.57±12.63mm. The left clavicle was longer (150.4mm) than the right one (146.8mm). Conoid tubercle (CT) and trapezoid tuberosity (TT) were 39.52±5.93mm and 17.96±3.42mm respectively from the lateral edge of clavicle. These distances correlated positively with the  length of clavicle and occupied 0.3 and 0.15 of total clavicular length respectively. The supero-inferior thickness of the lateral edge was 10.09±2.36mm. The distance of CT and TT positively correlated with clavicular length. The CT lies at a junction of lateral one third and medial 2/3 while the TT is midway between CT and lateral end. Designers of clavicular implants should consider these measurements and surgeons involved in fixation of acromoclavicular joints fractures.

Key words: Clavicle, conoid tubercle, trapezoid tuberosity.