Analysis of Plate Position and Factors Associated with Time to Flexor Tendon Rupture Following Volar Plate Fixation of Distal Radius Fractures

<b>Background:</b> Distal radius fractures are the most common fractures in the upper extremity. Volar plate fixation is a commonly performed surgical procedure for this fracture. Flexor tendon rupture is a serious postoperative complication due to attrition between the plate and tendon. This study aimed to analyse the factors associated with the time from surgery to tendon rupture, classify plate position and determine the incidence of flexor tendon rupture in relation to plate position. <b>Methods:</b> This multicentre retrospective study included 28 patients (24 women) with flexor tendon rupture following volar plate surgery for distal radius fractures. Plate positions were classified into four types based on plain radiographs. They were distal position (DP), dorsal angulation (DA), screw protrusion (SP) and proximal position (PP). The associations between the time to rupture and factors, including patient backgrounds and radiological parameters, were examined. <b>Results:</b> Thirty-five flexor tendons ruptured. All cases included Soong grade 1 or 2 plate prominence. The average time to tendon rupture was 101.5 months (SD 60.2, range: 1.1-202.1). No factors were significantly associated with time to rupture. Flexor tendon ruptures were associated with DA in 17 ruptures, DP in 11, SP in 6 and PP in 2. SP was observed in the non-locking system only. <b>Conclusions:</b> Attention must be paid to the possibility of tendon rupture in patients with Soong grade 1 or 2. The risk of flexor tendon rupture was highest in patients with prominent plates due to DA. <b>Level of Evidence:</b> Level IV (Therapeutic).