A 360° axial contact arc for fixation of radial head fractures can be reached combining anteromedial, anterolateral and midlateral arthroscopic portals

Abstract

Aim The aim of this study was to compare the effective working space in the axial plane of three different elbow arthroscopy portals to fix radial head (Rh) fractures. Background Arthroscopic fixation of Rh fractures is an alternative to open reduction and internal fixation, which presents the advantage of minimal surgical trauma. Methods A fresh-frozen cadaver specimen was obtained and prepared to mimic an arthroscopic setting. Standard anterolateral (AL), anteromedial (AM), and midlateral (ML) portals were established and circular reference system was marked on the Rh using the radial styloid as an anatomic reference for 0°. Ten independent examiners were then asked to move the forearm from maximal supination to maximal pronation and indicate with a K-wire the range in which they would feel confident with placing a cannulated screw, which would pass through the centre of the articular plane of the Rh (axial contact arc). This process was repeated from all three portals by each examiner. Every examiner remained blinded to other examiners’ measurements. Results The average axial contact arc that could be contacted from the AM portal measured 150 ± 14.14°, or 41.67% of the Rh circumference, while the one from the AL portal measured 257 ± 29.46°, or 71.39% of the Rh circumference, and that from the ML portal 212.5 ± 32.60°, or 59.03% of the Rh circumference. Considering all three portals, the whole Rh circumference could be contacted. The AM portal showed the smallest coefficient of variation (9.43%) as compared to the AL (11.46%), and the ML (15.34%) portals. Conclusions With an appropriate use of the standard AL, AM, and ML portals, the whole Rh circumference can be effectively contacted for fixation of Rh fractures. The AL portal shows a superiority in axial contact arc as compared to the AM and ML portals; the working space of the AM portal presents the smallest variability among different observers.