Is a vertical fracture fragment after indirect reduction acceptable in minimally invasive plate osteosynthesis for acute mid-shaft clavicular fractures?

Abstract

Purpose: Reduction and intraoperative maintenance of fracture fragments during minimally invasive plate osteosynthesis (MIPO) pose technical difficulties, particularly when the interposed fragment is angulated, prompting surgeons to attempt reduction due to concerns about nonunion or malunion. We aimed to compare the clinical and radiological outcomes of MIPO for mid-shaft clavicular fractures based on the reduced status of the interposed fragments.

Method: Fifty-seven patients who underwent MIPO for acute mid-shaft Robinson type 2B clavicular fractures were divided into two groups based on the alignment of the interposed fracture fragment. A vertical fracture fragment was defined as one tilted by >45° relative to the long axis of the proximal clavicular shaft. Radiological outcomes were evaluated using time to union, clavicle thickness, and length ratio after union compared with the healthy side. Clinical outcomes were assessed using the visual analog scale (VAS); the Korean Shoulder Score (KSS); Disability of the Arm, Shoulder, and Hand (DASH) score; and shoulder range of motion (ROM). Continuous variables were analyzed using Student's t-test or Mann-Whitney U test, based on data distribution.

Result: The vertical fragment group comprised 21 patients, and the nonvertical fragment group comprised 36. The mean time to union was similar between the vertical (4.48 ± 1.20 months) and nonvertical group (4.64 ± 1.17 months, p = 0.162). The groups showed comparable clavicular length and thickness ratios: 0.992 ± 0.040 vs. 1.076 ± 0.045 (p = 0.175), 1.189 ± 0.102 vs. 1.186 ± 0.271 (AP view, p = 0.165), and 1.121 ± 0.238 vs. 1.112 ± 0.230 (Lordotic view, p = 0.655), respectively. At 12 months, no significant differences were observed in VAS (0.3 ± 0.7 vs. 0.8 ± 0.8, p = 0.667), KSS (97.10 ± 6.30 vs. 96.75 ± 6.77, p = 0.940), and DASH (1.44 ± 3.64 vs. 2.00 ± 4.05, p = 0.501), or in ROM forward flexion (165.24 ± 9.28 vs. 162.78 ± 12.56, p = 0.464) and external rotation (60.95 ± 13.00 vs. 60.00 ± 13.47, p = 0.965).

Conclusion: Favorable radiological and clinical outcomes were achieved in all patients who underwent MIPO for mid-shaft clavicular fractures, regardless of whether the interposed fracture fragment after reduction was vertical.