Distal radius fractures are common upper limb injuries. Open reduction and internal fixation (ORIF) using a volar plate via the Henry approach often involves myotomy of the Pronator Quadratus (PQ) muscle, which may or may not be sutured postoperatively. The value of PQ repair remains debated, particularly regarding functional outcomes and protection of the Flexor Pollicis Longus (FPL) tendon. Objective: To compare the ultrasonographic healing of the PQ muscle with and without repair after volar plating, and to assess its potential role in FPL tendon protection. The hypothesis of our study was that the absence of PQ muscle suturing did not alter the plate-FPL distance, functional outcomes, or complications compared to sutured PQ.

We conducted a retrospective single-center study (October 2024–April 2025) including 48 patients with displaced distal radius fractures (AO A2) treated by ORIF. Twenty-three underwent PQ repair, and 25 did not. Ultrasonographic evaluations and clinical assessments were performed at final follow-up. Primary outcomes included PQ morphology and FPL-plate distance on ultrasound. Secondary outcomes comprised range of motion, grip/pinch strength, QuickDASH score, patient satisfaction, return to activity, and complications.

Ultrasonography showed significantly greater distances between the radius/FPL and plate/FPL in the non-repair group. PQ was morphologically thicker in the non-repair group, although not significantly. Functional outcomes favored the non-repair group in most metrics (VAS, ROM, QuickDASH), but without statistical significance. Two complications (carpal tunnel syndrome, tenosynovitis) occurred in the repair group only.

Our results support the view that PQ repair after volar plating of distal radius fractures does not provide significant functional or protective advantages. The critical factor in preventing tendon complications remains correct plate placement relative to the watershed line. Future research should focus on prospective, multicenter, randomised studies with larger cohorts and longer follow-up to confirm these results.

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