Intraoperative evaluation of rotational alignment in minimally invasive plate osteosynthesis for humeral shaft fractures using combined fluoroscopic and endoscopic assistance: surgical technique, clinical outcomes, and literature review.

INTRODUCTION

Minimally invasive plate osteosynthesis (MIPO) has become an established method for treating humeral shaft fractures; however, achieving accurate intraoperative rotational alignment remains challenging. This study describes an intraoperative evaluation technique using combined fluoroscopic and endoscopic assistance to improve the precision and objectivity of rotational correction during MIPO. MATERIALS AND

METHODS

From September 2019 to June 2023, twenty adult patients with simple transverse or wedge-type midshaft humeral fractures (AO/OTA type A or B) who underwent MIPO fixation were retrospectively reviewed. Demographic data, operative time, intraoperative fluoroscopy time, and postoperative outcomes were analyzed. Rotational difference (RD) between the operated and contralateral arms was measured using computed tomography (CT). Continuous variables between AO type A and B fractures were compared using the Mann–Whitney U test (p < 0.05).

RESULTS

The mean operative time was 113.5 min, and the mean fluoroscopy time was 75.9 s, which was significantly longer in AO type B fractures (p < 0.05). The average RD was 7.4° ± 4.7° (range, 1.9˚–17.5°). All fractures achieved union, with 18 cases healing within 3–6 months and 2 cases within 9–12 months. Mean angulation was 2.1° (coronal) and 2.0° (sagittal), and mean translation was 1.1 mm (coronal) and 1.3 mm (sagittal). No iatrogenic neurovascular injuries or infections were observed. There were no significant differences between AO type A and type B fractures in union rate or alignment parameters.

CONCLUSIONS

Combined fluoroscopic–endoscopic assistance enables objective intraoperative evaluation of humeral rotational alignment during MIPO without compromising soft-tissue preservation. This technique provides reliable reduction quality and consistent healing outcomes in AO type A and B humeral shaft fractures, representing a practical refinement of standard MIPO principles.