Lunate-capitate arthrodesis for scaphoid nonunion: a comparative study

Abstract

BackgroundScaphoid nonunion advanced collapse (SNAC) injuries are frequently associated with irreversible degenerative wrist arthritic changes that necessitate surgical intervention. Midcarpal fusion remains the mainstay of the management of SNAC II and III injuries. A successful four-corner fusion (4CF) relies on a stable lunate-capitate fusion (LCF). There have been reports of management relying solely on LCF. The outcomes of LC- and 4 C-fusions in SNAC injuries were not widely documented. The objective of this research is to provide valuable insights into the effectiveness of both fusion procedures in the management of SNAC II and III wrist injuries, with a focus on reporting associated complications, functional and radiological outcomes.Patients and methodsThis retrospective study encompassed 65 patients diagnosed with SNAC II and III wrist injuries who underwent limited wrist fusion procedures between 2015 and 2024, with a minimum of 2 years of postoperative follow-up. Exclusion criteria encompassed patients with carpal instability, prior wrist surgical interventions, and scapholunate advanced collapse. Following the fusion procedure performed, patients were stratified into two groups: the LCF group consisting of 31 patients, and the 4CF group comprising 34 patients. Preoperative and intraoperative data were retrieved from the patient’s medical records. At their final follow-up appointments, patients underwent comprehensive radiographic and clinical evaluations. Clinical outcomes including hand grip strength, range of motion, the Disabilities of the Arm, Shoulder, and Hand Score, and the Mayo Modified Wrist Score, were compared between groups. Any associated complications were reported.ResultsThe average healing time was 74.7 ± 15.6 and 72.2 ± 13.2 days for the LCF and 4CF groups, respectively. At the final visit, all patients showed functional improvement relative to their preoperative status, with comparable wrist range of motions observed in both groups. The functional wrist scores were slightly better in the LCF patients (P > 0.05). The average grip strength was significantly greater in the LCF group (P = 0.04), with mean strength values of 86.8% and 82.1% of the contralateral side, for the LCF and 4CF groups, respectively.ConclusionThe LCF is not less efficient than the 4CF in the treatment of SNAC II and III wrist injuries. Through a less time-consuming procedure, LCF can efficiently provide comparable results to 4CF.Level of evidencelevel IV evidence.