Significance of the Sparing Pronator Quadratus for Volar Plating of Distal Radius Fractures: A Prospective Study.

Background Pronator quadratus (PQ) acts as the pronator of the wrist and stabiliser of the distal radioulnar joint; it also provides a protective cover over the edge of the plate, preventing friction and subsequent rupture of flexor tendons. The repair of PQ is often difficult, and its durability is questionable; hence, preserving the PQ while volar plating distal radius fractures is advocated. Methods In this prospective randomised trial, 60 patients with a fracture of the distal end of the radius of AO-type (Arbeitsgemeinschaft für Osteosynthesefragen) 23 A2, A3, B1, B3, C1, and C2 were treated with volar plate fixation using either the PQ-releasing and repair approach (Group A, n = 30) or the PQ-sparing approach (Group B, n = 30), allowed by simple randomisation. Outcomes recorded included operative time, number of intraoperative radiation shots, range of motion, grip strength, Quick DASH (Disabilities of Arm, Shoulder, and Hand) score, visual analog scale (VAS) score, and complications, if any. Results Follow-up was done at 1, 3, 6, and 12 months. In the PQ-releasing group, the mean operative time was 54 ± 13 minutes, and the mean number of C-arm shots was 22 ± 7, whereas in the PQ-sparing group, the mean operative time was 82 ± 15 minutes, and the mean number of C-arm shots was 37 ± 7. Palmar flexion, supination, and pronation were significantly better at all the follow-ups until 12 months; however, dorsiflexion was better only until six months in the PQ-sparing group when compared to the PQ-releasing group. DASH score, VAS score, and grip strength were also significantly better until six months in the PQ-sparing group, with no significant difference at the 12-month follow-up in both groups. Conclusions There is statistically significant earlier functional recovery by preserving the PQ muscle for volar plating of distal radius fractures, with no increase in complication rate, and an attempt to preserve the PQ should be made.