Risk factors for hardware-related complications after extra-articular distal humerus fracture fixation using an anatomical locking plate

Abstract

Purpose: We aimed to identify the incidence and risk factors of hardware-related complications in patients treated with anatomical locking plate fixation for extra-articular distal humerus fractures.

Methods: From 2013 to 2020, patients with extra-articular distal humerus fractures who underwent open reduction and internal fixation with an extra-articular distal humerus locking plate (EADHP) were retrospectively reviewed and categorized according to the presence/absence of hardware-related complications. Hardware-related complications were defined as the occurrence of skin prominence on the plate and discomfort in activities of daily living. Patient demographics, the lateral condylar angle, lateral body length, shaft-condylar angle of the humerus, and plate length were analyzed.

Results: Of the 29 patients, 10 (34%) did not develop hardware-related complications (group A), whereas 19 (66%) did (group B). Patient demographics did not differ between the groups. However, the number of patients who underwent hardware removal was significantly greater in group B (16/19) than in group A (4/10; p = 0.032). Radiologic assessment revealed no significant difference in the lateral condylar or shaft-condylar angle. However, the lateral body length was greater in group A than in group B (44.5 ± 4.8 vs. 39.5 ± 3.7, p = 0.007). The plate length significantly differed between the groups. Twelve of 19 (63%) patients in group B received short-hole plates (six holes), while nine of ten (90%) patients in group A received long-hole plates (eight holes). In the multivariable analysis, the lateral body length of the distal humerus (p = 0.047, odds ratio = 0.734, 95% confidence interval: 0.542-0.996) and plate length (p = 0.036, odds ratio = 0.076, 95% confidence interval: 0.542-0.996) were associated with hardware-related complications.

Conclusions: Most patients developed hardware-related complications, particularly with short plates, mainly because of the narrow lateral body length of the distal humerus. Surgeons should be careful to secure EADHP in the appropriate position, especially when short plates are used in patients with narrow lateral body length.

Keywords: Complication; Fracture; Humerus; Locking plate.