Positional Screw Effect in the Treatment of Humeral Shaft Fractures Using a Minimally Invasive Plate Osteosynthesis Technique.

Background: This study compares the difference in the clinical and radiologic outcomes when minimally invasive plate osteosynthesis (MIPO) technique is performed with or without using a positional screw in the treatment of humeral shaft fractures.

Methods: From January 2010 to January 2021, a retrospective study was conducted on a total of 63 patients who underwent the MIPO technique for the treatment of humeral shaft fractures. We divided these patients into 2 groups: in group I, patients underwent MIPO without a positional screw; in group II, patients underwent MIPO with a positional screw. We compared functional outcomes including the American Shoulder and Elbow Surgeons score, University of California at Los Angeles score, Simple Shoulder Test, range of motion before and after surgery, operation time, blood loss, and complications. And we compared radiologic outcomes including pre- and postoperative anteroposterior (AP) and lateral displacement of the fracture and union time on plain radiographs.

Results: The average patient age was 64.6 ± 15.1 years (range, 25-88 years). Group I consisted of 30 patients (10 men and 20 women), and group II consisted of 33 patients (11 men and 22 women). Between the 2 groups, there was no statistically significant difference in sex, body mass index, functional scores, AP and lateral displacement of the fracture on postoperative x-ray, operation time, and blood loss. In group II, a faster bony union was obtained than that in group I (4.6 vs. 6.4 months). Complications included 2 cases of transient radial nerve palsy in both groups and metallic failures (2 in group I and 1 in group II).

Conclusions: When performing MIPO for humeral shaft fractures, adding a positional screw could be more stabilizing than bridge plating without a positional screw, leading to faster bony union. A positional screw might help control interfragmentary movement without inhibiting essential interfragmentary movement for fracture healing.