A biomechanical comparison of hook plate vs. superolateral locking plate with coracoclavicular suture fixation for distal third clavicle fractures with coracoclavicular ligament disruption.

BACKGROUND

Unstable distal third clavicle fractures involving coracoclavicular (CC) ligament disruption are prone to nonunion and often require surgical fixation. While hook plates (HPs) and superolateral locking plate (SLP) with CC suture augmentation are both commonly used, biomechanical comparisons are limited.

METHODS

Eighteen fresh-frozen adult cadaveric shoulders (9 contralateral matched pairs) were randomized to receive either HPs or SLP with CC suture fixation constructs after simulated Neer type IIb distal clavicle fractures. Constructs were cyclically loaded at 70 N for 500 cycles, followed by load-to-failure testing. Displacement and failure modes were recorded and statistically analyzed using paired t-tests (P < .05).

RESULTS

At 50 N and 70 N, SLP with CC suture fixation demonstrated significantly less displacement than HPs (P < .05) across all measured cycles. Comparisons were made using a paired t-test. Mean displacement at 70 N at cycle 500 was 5.5 mm (HPs) vs. 3.0 mm (SLP with CC suture fixation). SLP with CC suture fixation constructs also had significantly higher load to failure (364.8 N vs. 281.9 N, P < .05). Failure modes differed. HPs typically failed by hook bending and screw pullout, while SLP with CC suture fixation failed primarily via suture rupture or anchor pullout.

CONCLUSION

SLP with CC suture fixation constructs provide superior biomechanical stability compared to HPs in Neer type IIb fractures, with less displacement and greater failure strength under load. These results support the clinical use of SLP with CC suture fixation as a robust alternative to traditional hook plating.