Management of extra-articular fracture of the distal humerus with the upside-down use of PHILOS plates in front of the humerus: a retrospective study of 20 patients after 28.3 months.

Background: Extra-articular distal humerus locking plates (EADHPs) have been widely employed for the treatment of extra-articular fractures of the distal humerus, but interference with the radial nerve and poor fastening of distal fracture fragments by screws remain. The aim of this study is to evaluate the clinical and imaging effects of the anterolateral approach in the treatment of extra-articular fractures of the distal humerus with the upside-down use of proximal humerus internal locking system (PHILOS) plates in front of the humerus.

Method: A retrospective analysis (10/2018-10/2022) was conducted on the clinical data of patients with extra-articular fractures of the distal humerus treated with the upside-down use of the PHILOS via the anterolateral approach. The fracture union time, range of motion of the elbow joint, Mayo elbow performance score (MEPS), Disabilities of the Arm, Shoulder and Hand (DASH) score, Visual Analogue Scale (VAS) score for pain and incidence of complications were analysed at the final follow-up.

Results: A total of 20 patients (11 males, 9 females) with a mean age of 40.3 ± 17.0 years (16-87 years) and a follow-up of 28.3 ± 10.8 months (15-53 months) were evaluated. The average number of screws in the distal humeral fragment was 5.7 ± 0.6. The average fracture union time was 23.3 ± 3.3 weeks. The mean longest and shortest cortical lengths from the coronoid fossa were 87.3 ± 13.4 mm and 47.9 ± 9.4 mm, respectively. At the final follow-up, the average range of elbow motion was - 3.3 ± 2.6° of extension and 135.1 ± 3.1° of flexion. The mean MEPS score was 97.8 ± 6.0. The mean DASH score was 1.25 ± 3.6 (range, 0-15.9), and the mean VAS score was 0.1 ± 0.4 (range, 0-2). None of the patients developed serious complications that required reoperation.

Conclusions: The upside-down use of PHILOS plates in front of the humerus has good results in the treatment of extra-articular fractures of the distal humerus, so it is an alternative for fixing distal humerus extra-articular diaphyseal fractures when EADHPs are not suitable or preferred, especially for smaller distal fracture fragments, and reducing interference with the radial nerve.