Distal augmentation in unstable distal clavicle fractures: a retrospective cohort study of 101 cases

Introduction: The optimal management strategy for unstable distal clavicular fractures remains controversial. Recent studies on plate techniques have reported good-to-excellent outcomes with no serious complications. The questions are that: (1) Does the use of wire augmentation with locking plate in distal part (distal wire augmentation) reduce radiographic loss of reduction (RLOR) and get earlier bony union in distal clavicular fractures? (2) Which fixation methods are associated with a higher incidence of acromioclavicular (AC) joints arthritis or subluxation? We collected and analyzed clinical studies on different plate fixation methods for unstable fractures to identify the best surgical modality.

Methods: This retrospective case-control study included 101 patients with Neer types IIB and V unstable distal clavicle fractures treated using plate techniques. The patients were divided into four groups according to the surgical procedure: hook plate (HP group) (n = 13), lateral locking plate alone (LP group) (n = 41), locking plate with coracoclavicular (CC) ligament suture repair (LPC group) (n = 26), and locking plate with distal wire augmentation (LPA group) without CC repair (n = 21). The clinical outcomes of shoulder function were the mean Constant score and the University of California-Los Angeles (UCLA) shoulder scale. The bony union time, loss of CC distance reduction, and AC joint condition were used to evaluate the radiographic results. One-way ANOVA, Kruskal-Wallis test, and chi-square test were performed to compare differences between groups. Multiple p-value comparison corrections were calculated using the Bonferroni method.

Results: There were no significant differences in the mean Constant and UCLA scores among the groups after 1 year of follow-up. All fractures healed. The LPA and HP groups achieved earlier bone union (LPA 8.4 weeks, HP 8.9 weeks, LP 12.6 weeks, and LPC 13.4 weeks, P = 0.000); however, the HP group had the highest complication rate and required bone removal (LPA 4.0%, HP 23.1%, LP 0.0%, LPC 0.0%, P = 0.003). A low rate of RLOR was observed in the LPA group (LPA 9.5%, HP 23.1%, LP 22.0%, LPC 30.8%, P = 0.362). The incidence of AC joint subluxation was higher in the Neer type V group and was unrelated to surgical methods.

Conclusions: Hook plate and locking plate with distal wire augmentation in distal clavicle fractures result in an earlier time to bone union when compared with CC suture repair or non-CC suture repair techniques. However, HP may have the higher complication rate and require subsequent implant removal. The incorporation of distal wire augmentation appears to be beneficial in maintaining fracture reduction. In the future, larger prospective studies are needed to confirm these findings.

Level of evidence: Level III, therapeutic study.