The association of clavicular, coracoidal and coracoclavicular radiographic tunnel position with loss of reduction after bidirectional acromioclavicular joint stabilization

Abstract

Introduction

Loss of reduction (LOR) is common after acromioclavicular joint (ACJ) stabilization. Tunnel position is a possible risk factor but has not been investigated after bidirectional stabilization. The aim was to analyze if clavicular, coracoidal and coracoclavicular (CC) radiographic tunnel position would be associated with LOR and clinical outcomes after bidirectional ACJ stabilization. 

Materials and methods

Male patients (18–55 years) with acute, high-grade ACJ dislocations (Rockwood type V), treated with arthroscopically assisted bidirectional stabilization were included. Bilateral anteroposterior views at the 6-weeks-follow-up served for measuring the clavicular tunnel position (from lateral) and the coracoidal tunnel position (from medial) absolutely and relatively (relative to clavicle length and coracoid width, respectively), as well as the coracoid clavicular tunnel angle (CCTA). The association between tunnel parameters and LOR (side-comparative CC difference between the 6-weeks-follow-up and the final follow-up ≥ 2 years) was analyzed. Radiographic failures were defined as LOR ≥ 6 mm.

Results

Fifty-six patients with a mean age of 38.9 ± 10.7 years and a mean follow-up of 33.0 months (range, 24–55 months) were included. The mean LOR was 3.6 mm (95% confidence interval, CI 3.0–4.2 mm), with 6 radiographic failures (11%). A more lateral relative coracoidal tunnel position was associated with more LOR (r = 0.271; p = 0.043), with a cut-off value of > 0.61 for more LOR [4.7 mm (3.2–6.3 mm) vs. 3.3 mm (2.7–3.8 mm); p = 0.029]. A larger CCTA correlated with less LOR (r= − 0.276; p = 0.04), with a cut-off value of > 14° [2.6 mm (1.8–2.3 mm) vs. 4.0 mm (3.3–4.7 mm); p = 0.037]. No tunnel parameter was associated with radiographic failure or clinical outcomes (p > 0.05, respectively).

Conclusions

Radiographic tunnel position in bidirectional, arthroscopically assisted ACJ stabilization has only small implications on the radiographic outcome and shows no association with radiographic failure or inferior clinical outcomes.