Significance of a Pronator Quadratus-Sparing Approach for Volar Locking Plate Fixation of Comminuted Intra-articular Fractures of the Distal Radius

Abstract

Background: The preservation of the integrity of the pronator quadratus (PQ) muscle is expected to have many benefits, particularly in cases of highly comminuted intra-articular fractures of the distal radius. Therefore, we examined the significance of a PQ muscle-sparing approach for volar locking plate (VLP) fixation of these types of fractures.

Methods: Sixty-five patients who sustained AO Foundation and Orthopaedic Trauma Association (AO/OTA) type C2 and C3 distal radius fractures were treated with VLP fixation using either a PQ muscle release and repair (PQ-releasing group, n = 30) or a PQ muscle-sparing approach (PQ-sparing group, n = 35). Radiographic parameters, active range of motion (ROM), percentage of the grip power of the injured hand compared with that of the opposite hand, wrist pain visual analog scale (VAS) score, and Quick Disability of the Arm, Shoulder, and Hand (DASH) score (disability/symptom) were evaluated monthly up to 12 months after surgery.

Results: The mean VAS score was significantly lower in the PQ-sparing group at 2, 3, and 4 months postoperatively than in the PQ-releasing group. Furthermore, the mean Quick DASH score in the PQ-sparing group was significantly lower than that in the PQ-releasing group at 1 and 2 months postoperatively. There were no significant differences, however, in the other functional parameters in the groups through the observation period.

Conclusions: The PQ muscle-sparing approach appears to achieve satisfactory results in patients undergoing VLP fixation of comminuted intra-articular fractures of the distal radius.

Keywords: comminuted intra-articular fracture; distal radius fracture; pronator quadratus muscle; surgical approach; volar locking plate.

Figure 1.

Surgical approaches to the distal radius. Note. (a) The PQ muscle–releasing approach: The PQ muscle is incised sharply along its proximal, radial, and distal borders along the distal radius using a rectangular-shaped incision. (b) The PQ muscle–sparing approach: Along with a subperiosteal retrograde release of the PQ muscle from its fibrous distal attachments to the distal radius, its muscle belly is carefully exfoliated to reduce any palmar protruded fragments with an elevator to form a path for the plate without enlarging the transverse tear caused by the fracture and a locking plate is slid underneath the PQ muscle in a retrograde direction. (c) Radiograph of volar locking plate fixation showing double-tiered subchondral support. Left = anteroposterior view; Right = lateral view; PQ, pronator quadratus.