A biomechanical comparison of new techniques for distal clavicular fracture repair versus locked plating

Abstract

Background: Unstable distal clavicular fractures treated surgically are associated with high failure rates and hardware-related complications. Newer techniques have shown promising early clinical results with fewer hardware complications; however, their biomechanical performance has not been assessed. This study biomechanically compared a distal-third locking plate with 3 newer techniques that incorporate coracoid fixation into the construct.

Methods: The study randomized 36 adult fresh frozen cadaveric shoulders to 4 groups: (1) distal-third locking plate (P); (2) distal-third locking plate with a coracoid button augmentation (P + CB); (3) coracoclavicular button (CB); and (4) coracoclavicular button with coracoclavicular ligament reconstruction using semitendinosus allograft (CB + CC). After fixation, each specimen was stressed in the coronal plane. Cyclic displacement, load at 10-mm displacement, and ultimate load to failure were measured.

Results: All 3 experimental groups biomechanically outperformed the locking plate. Mean load to failure was significantly higher in the CB (343 ± 76 N) and CB + CC (349 ± 94 N) groups compared with the P group (193 ± 52 N). There was also significantly less cyclic displacement in the CB (4.3 ± 1.9 mm) and CB + CC (4.4 ± 1.9 mm) groups compared with the P group (8.2 ± 2.9 mm). With respect to load at 10 mm of displacement, which essentially measures a clinical failure, the P + CB (235 ± 112 N), CB (253 ± 111 N), and CB+CC (238 ± 76 N) experimental groups significantly outperformed the P group (96 ± 29 N).

Conclusions: CB and CB + CC techniques demonstrated more than 75% greater strength than the traditional locking plate alone. Coupled with greater overall construct strength and lower-profile hardware, these newer techniques may result in improved clinical outcome and fewer hardware-related complications.

Keywords: Distal clavicular fracture; biomechanical study; coracoclavicular button; cortical button; distal-third locking plate; lateral clavicle.