The relationship between the subclavian vessels and brachial plexus and the overlying clavicle: Anatomical study with application to plate osteosynthesis.

Abstract

A subclavian artery aneurysm after clavicle fracture and plate osteosynthesis in a suspected case of a screw that was too long led us to investigate body donor cadavers. The aim was to verify clavicle variability, and the course of the neurovascular bundle in relation to the clavicle and to the osteosynthesis plate, in order to clarify safe zones for plate and screw fixation. We used one fresh frozen and 25 embalmed donors for in situ measurements: (1) length and craniocaudal thickness of the clavicle, (2) distances between the sternal end of the clavicle and the center of parts of the neurovascular bundle. The clavicle was 15.15cm long. The mean distances from the sternal end of the clavicle were 5.62 cm to the subclavian vein, 6.75 cm to the subclavian artery and 8.42 cm to the cords of the brachial plexus. The subclavius muscle was 1cm thick. Because of sex differences in length and distances, we recorded the distances between the sternal end and parts of the neurovascular bundle as ratios of clavicle length (at-risk area) to provide sex-independent parameters: 0.379 for the vein, 0.449 for the artery and 0.554 for the nerve. The neurovascular bundle runs below the clavicle between the medial fourth and three fifths of clavicle length. To avoid iatrogenic neurovascular injuries, special caution is necessary during drilling and screwing the osteosynthesis. We also recommend using screws shorter than 1.4cm.