Dorsal minimally invasive fixation technique for distal radius fractures with dorsoulnar fragment involvement: anatomical validation and clinical outcomes

Background Distal radius fractures (DRF) involving the dorsoulnar fragment (DUF) are categorized as unstable fractures. Inadequate fixation of the DUF will compromise the stability of both the radiocarpal joint and the distal radioulnar joint. Currently, the traditional dorsal surgical approach is associated with substantial trauma, which often leads to tendon injury and adhesion. This study aimed to assess the clinical outcomes of dorsal plating for the treatment of the DUF via a minimally invasive surgical approach. Methods We developed a dorsal minimally invasive surgical approach by dissecting 2 cadavers and recording relevant data. We retrospectively analyzed 89 patients who underwent surgical treatment for C-type DRF between 2020 and 2024. Based on the different treatment methods, they were divided into the volar locking plate (VLP) group and the volar locking plate combined with dorsal low-profile mini plate (VDP) group. General data, inpatient data, and postoperative complications during follow-up were recorded. The X-ray images before surgery, after surgery, and at the last follow-up were analyzed. Clinical outcome information including active range of motion, radiographs, PRWE and DASH questionnaires were collected. Results Fifty-seven patients underwent open reduction and volar locking plate, while 32 underwent volar locking plate combined with dorsal low-profile mini plate via a minimally invasive surgical approach. The VLP group had significantly shorter operation time, length of the surgical incision, and X-ray fluoroscopy compared to the VDP group (all p  < 0.001). At the postoperative and last follow-up, the radiographic parameters (ulnar variance and articular step-off) were better in the VDP group than in the VLP group ( p  = 0.011, p  < 0.001, respectively). VDP group demonstrated superior wrist flexion, pronation function and Gartland-Werley compared with its VLP counterpart ( p  = 0.066, p  = 0.011, p  = 0.017). However, there was no significant difference in DASH score, and incidence of postoperative complications between the two groups. Conclusion Both volar approach plating combined with dorsal approach fixation and volar approach plating yield satisfactory postoperative outcomes in the treatment of DRF involving the DUF. However, the former more effectively prevents redisplacement of the DUF and wrist joint function.