Coracoid Process Morphology using 3D-CT Imaging in a Malaysian Population

Abstract

INTRODUCTION: The aims of this study are to define the coracoid process anatomy in a Malaysian population, carried out on patients in Hospital Serdang with specific emphasis on the dimension of the base of coracoid process which is important in coraco-acromial (CC) ligament reconstruction, to define the average amount of bone available for use in coracoid transfer, and to compare the size of coracoid process based on gender and race, and with findings in previous studies. The coracoid process is significant as a bony landmark in many surgical procedures around the shoulder joint. The coracoid is used by surgeons for graft in coracoid transfer procedure for shoulder instability and also for coraco- acromial (CC) ligament reconstruction procedures1-3. The anatomical dimension of coracoid therefore is crucial as the size will determine how much of the coracoid process can be harvested as a graft during coracoid transfers procedure. In CC ligament reconstruction, inappropriate size of drill, size of implants and even the inaccurate trajectory of tunnel drilling can increase the risk of coracoid fracture and implant pull-out. By having our own data for the population in this region, it may provide information to surgeons on how much cortical wall remains during tunnel preparation in CC ligaments reconstruction. MATERIALS AND METHODS: Fifteen pairs of computed tomography (CT) based 3-dimensional models of shoulders of patients aged between 20 to 60 years old were examined. The mean dimensions of coracoid were measured and compared with regards to gender and race. The data were also compared to previously published studies. RESULTS: The mean length of the coracoid process was 37.94 ± 4.30 mm. Male subjects were found to have larger-sized coracoids in all dimensions as compared to female subjects. The mean tip of coracoid dimension overall was 19.99 + 1.93mm length x 10.03 + 1.48mm height x 11.63 + 2.12mm width. The mean base of coracoid dimension was 18.96 + 3.71mm length x 13.84 + 1.76mm width. No significant differences were observed with regards to racial denomination. The overall coracoid size measurements were found to be smaller compared to previous studies done on the Western population. CONCLUSION: This study may suggest that Malaysians have smaller coracoid dimension compared to Caucasians. The findings further suggest that the incidence of coracoid fracture and implants pull out in Malaysian subjects may be higher.

Keywords

• coracoid process
• coracoid anatomy
• coracoid dimension
• Malaysian population