Flexor tenosynovitis is a well-recognized complication following volar plate fixation of distal radius fractures (DRFs). The aim of our study was to highlight the risk factors of flexor tenosynovitis.

We conducted a retrospective case-control study including 200 patients (50 cases and 150 controls) who underwent osteosynthesis with an Aptus™ volar locking plate. We analyzed demographic, surgical, and radiological factors associated with flexor tenosynovitis requiring hardware removal. Univariate and multivariate analyses were performed to identify independent risk factors.

The prevalence of hardware removal for flexor tenosynovitis was 3.7% (50 patients). The mean time to symptom onset was 19.4 months ± 22.75 (range: 2–108), with an average delay of 3.8 months ±3.34 (range: 0.2–15) before hardware removal. In univariate analysis, significant risk factors included plate positioning in Soong C ( p  = 0.018), placement below the watershed line ( p   <  0.01), and postoperative immobilization with a plaster splint ( p   <  0.001). In multivariate analysis, only plate position relative to the watershed line ( p  = 0.038) and postoperative immobilization type ( p   <  0.001) remained significant. Pronator quadratus repair was more frequent in the control group ( p  = 0.046) but was not a significant protective factor in multivariate analysis ( p  = 0.11).

Incorrect plate positioning, particularly relative to the Soong zones and watershed line, is a key risk factor for flexor tenosynovitis. Postoperative immobilization type may also play a role. Early plate removal should be considered in high-risk cases.

III; retrospective case control study.