Cause of Extensor Pollicis Longus Ruptures After Distal Radius Fracture Fixation Using a Volar Plate.

Background: This research sought to analyze a cohort of patients with extensor pollicis longus (EPL) ruptures after volar locked plating of a distal radius fracture (DRF) to characterize the incidence of ruptures that are unlikely to be related to dorsal screw prominence.

Methods: This is a retrospective, observational, descriptive cohort study of adults with operative fixation of a closed DRF and an EPL rupture between 2002 and 2022. Eighteen patients with operative fixation using a volar plate of a closed DRF had an EPL rupture. The cohort consisted of 66% women with an average age of 57.5 years. Median follow-up was 14.5 months.

Results: The incidence of EPL rupture was 0.4% (18/4768). The average time from DRF and DRF fixation to EPL rupture was 3.7 and 3.4 months, respectively. Based on the operative record, in 2 of the 18 patients (11%), the rupture was directly attributable to prominent hardware; however, in 4 of the 18 patients (22%), the rupture was not related to prominent hardware, and the cause was indeterminate in 12 patients (67%). Radiologic analysis of those in the indeterminate group demonstrated that 5 of the 12 patients had screws that had a high probability of being prominent.

Conclusions: The incidence of EPL rupture after volar plating of DRF is between 0% and 1% and usually occurs about 3 months after fixation. Approximately 50% of EPL ruptures are attributable to prominent dorsal screws. Although screw prominence is an important cause of EPL rupture, it is not the sole cause of rupture.