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A prospective study of postoperative pain following minimally invasive surgery with an extra-short volar locking plate for distal radius fractures

In standard volar locking plate (VLP) fixation for distal radius fractures, it is usually necessary to perform a longitudinal incision of the pronator quadratus (PQ) muscle. We have performed minimally invasive surgery (MIS) using an extra-short plate for internal fixation while preserving the PQ muscle in some simple fracture cases. In this prospective study, we hypothesized that MIS would cause less postoperative pain than standard VLP fixation.

Among 105 patients who underwent VLP surgery for distal radius fractures between April 1, 2022 and July 31, 2023, 109 patients for whom surgical treatment with MIS was deemed desirable based on fracture type, etc., were randomly assigned to the MIS group that underwent MIS preserving the PQ muscle or the standard group that underwent standard VLP fixation performing a longitudinal incision of the PQ muscle. The primary endpoint of the study was a randomized, open-label comparison of the two groups. The primary endpoint was pain from postoperative day 1 (POD1) to postoperative day 7 (POD7) as assessed by the Numerical Rating Scale (NRS), and secondary endpoints were patient information, imaging, and functional assessment (quick DASH, Mayo wrist score). In the AO classification, the MIS group had 12 limbs of type A, 1 limb of type B, and 5 limbs of type C, while the VLP group had 13 limbs of type A, 4 limbs of type B, and 8 limbs of type C.

The MIS group consisted of 18 patients and 18 limbs, and the standard group consisted of 25 patients and 25 limbs. The pain NRS of the MIS and VLP groups were 7.67 and 8.00 (p=0.222) in POD1, 4.50 and 6.03 (p=0.005) in POD2, 3.83 and 5.35 (p=0.003) in POD3, and 4.50 and 6.03 (p=0.003) in POD4, respectively. 50 and 6.03 (p=0.005), 3.83 and 5.35 (p=0.003) for POD3, 3.28 and 4.26 (p=0.036) for POD4, 2.44 and 3.61 (p=0.016) for POD5, 1.83 and 2.58 (p=0.036) for POD6 and 1.39 and 1.68 (p=0.186). No significant difference was found in postoperative functional assessment of the MIS and VLP groups were 5.70 and 3.81 (p=0.172) for quick DASH and 87.6 and 90.3 (p=0.120) for Mayo wrist score, respectively.

From postoperative days 2 to 6, the NRS was significantly lower in the MIS group than in the standard group, and MIS reduced pain in the early postoperative period. The reduction of surgical invasiveness, such as not cutting longitudinally through the PQ muscle, was thought to have reduced early postoperative pain. MIS for distal radius fractures causes less early postoperative pain than standard VLP fixation.

minimally invasive, surgery, volar locking plate, distal radius, fracture