A computer tomography-based anthropomorphic study of forearm osteology: implications for prosthetic design

Abstract

Background: The aim of this study was to accurately establish the variability in the anatomy of the radius and ulna in the context of the design of an intramedullary nail for both bones. 

Methods: Forearm computed tomography scans were used to measure the specific internal and external anatomy of the radius and ulna in adult patients. Patients with fractures or dislocations involving either the radius and/or ulna were excluded.

Results: A total of 97 scans, comprising 84% male and 16% female patients, were included. The mean radius length was 238.43±18.38 mm (95% CI 234.60–241.74 mm). The mean curvature was an arc with a radius of 561.43±93.49 mm (95% CI 543.09–580.78 mm). The smallest measurement of the canal width was 5.17 mm (95% CI 4.87–5.47 mm). The ulna showed a mean length of 259.90±19.88 mm (95% CI 255.89–263.91 mm). The smallest measurement of the canal width was 4.80±1.30 mm (95% CI 4.53–5.87 mm). The mean proximal shaft angle was 11.39±3.30° (95% CI 10.76–12.82°).

Conclusion: This computed tomography scan-based anthropomorphic study has identified novel anatomical features and associations of human forearm bones. This information will be used in the design and manufacture of anatomic intramedullary devices to better manage radius and ulna fractures or pathology.

Level of evidence: Level 4