Triceps-sparing versus triceps-splitting approaches for OTA 12A-C and 13A2-3 distal-third humeral shaft fractures have similar 1 year functional outcomes.

Purpose: To compare functional outcomes of distal third humeral shaft fractures (OTA 12A-C and 13A2-3) treated with either triceps-splitting or triceps-sparing surgical approach. Secondarily, the purpose was to compare healing and complication rates between the two surgical approaches.

Method: A retrospective review of a prospectively collected humeral shaft registry was performed from 01/2018-12/2024. Inclusion criteria was: age > 18yo, OTA 12A-C or 13A2-3 distal third humeral shaft fracture, either triceps-splitting or triceps-sparing surgical approach, and minimum 1-year follow-up. The primary outcome was 1-year postoperative functional status measured using the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Secondary outcomes measures included surgical time, radiographic union times, union rates, iatrogenic nerve injury, fracture related infection, hardware failure, reoperation, and documented range of motion (ROM) at last follow-up. Univariate analysis with two-tailed Student's t-tests and chi-square tests was used to compare demographics, injury and surgical characteristics.

Result: A total of 39 patients met inclusion criteria: 27 (69.2%) underwent a triceps-splitting approach and 12 (30.8%) a triceps-sparing approach. There were no significant differences in baseline demographics. At final follow-up, functional outcomes were comparable. DASH scores were similar between groups (7.7 ± 13.8 vs 7.0 ± 9.0, p = 0.89), as were fracture healing times (5.5 ± 2.2 vs 6.1 ± 3.6 months, p = 0.63), with all fractures achieving union. Surgical duration was shorter in the splitting group (83 ± 42 vs 103 ± 52 min, p = 0.26), though not statistically significant. No hardware-related complications were reported. Two radial nerve palsies (7.6%) occurred in the splitting group, while one postoperative infection (8.3%) occurred in the sparing group (all p > 0.05). Elbow range of motion was similar. Mean flexion was 137.9 ± 10.0° in the splitting group vs 131.3 ± 30.0° in the sparing group (p = 0.47); mean extension was 2.3 ± 4.7° vs 4.6 ± 5.5°, respectively (p = 0.21).

Conclusion: There is no difference in 1-year functional outcomes as measured by the DASH score between the triceps-splitting versus triceps-sparing approach for surgical fixation of the OTA 12A-C and 13A2-3 distal third humeral shaft fractures. Either surgical approach is viable for distal third humeral shaft fractures.

Level Of Evidence: Level III.