Locking versus nonlocking superior plate fixations for displaced midshaft clavicle fractures: A prospective randomized trial comparing clinical and radiografic results.

Background: It is unknown whether locking or nonlocking superior plate fixation is better for managing displaced midshaft clavicle fractures. Therefore, we aimed to compare the clinical and radiographic outcomes of locking and nonlocking superior plate fixation of displaced midshaft clavicle fractures.

Methods: A total of 102 consecutive patients with displaced midshaft clavicle fractures (2B1 and 2B2 in Robinson classification) participated in this randomized controlled trial; 12 patients were excluded. Surgeries were performed using a 3.5-mm Locking Compression Plate (LCP) between 2007 and 2015. Patients were treated either with a locking plate (group L, n = 45) or a nonlocking plate (group N, n = 45). In both groups, the plates were fixed to the proximal and distal clavicle with two and/or three screws, respectively. The main outcome measures were complication rates, time to bone union, and Constant score.

Results: Forty-two patients in group L (mean age, 45.9 years) and 41 in group N (mean age, 43.6 years) were followed. The overall complication rates in groups L and N were 7.2% (three peri-implant fractures) and 7.3% (non-union, deformed plate, and peri-implant fracture), respectively (p = .98). The average time to union significantly differed between groups (L vs. N: 13.0 ± 4.1 vs. 17.5 ± 6.3 weeks; p < .01). However, the Constant score at the final follow-up was not significantly different between groups (L vs. N: 87.0 ± 12.3 vs. 89.8 ± 9.1).

Conclusions: Similar complication rates and clinical results were found for locking and nonlocking superior plate fixation for displaced midshaft clavicle fractures. However, the time to bone union was shorter with the locking plate. This study suggests that both plating systems are effective for treating displaced midshaft clavicle fractures.

Level Of Evidence: Therapeutic, level I.