Scaphocapitate fusion in stage III Kienböck’s disease: effects of lunarectomy on postoperative pain and function

Abstract

Background

Kienböck’s disease (KD) is a progressive condition characterized by avascular necrosis of the lunate, leading to carpal collapse and wrist dysfunction. Scaphocapitate fusion (SCF) is a salvage procedure often used in advanced stages of KD to stabilize the wrist and alleviate symptoms. This study aimed to evaluate the clinical and radiological outcomes of SCF in stage III KD, with a specific focus on the impact of lunarectomy on postoperative pain and function.

Materials and methods

This retrospective study included 25 patients with stage III KD who received SCF treatment and were followed between December 2019 and August 2024. Patients were categorized into groups of lunarectomy (n = 14) and lunate preservation (n = 11). Clinical outcomes were assessed using grip strength, range of motion (ROM), Visual Analog Scale (VAS) for pain, Modified Mayo Wrist Score (MMWS), and Disabilities of the Arm, Shoulder, and Hand (DASH) score. Radiological evaluations included measurements of carpal alignment and fusion success.

Results

SCF significantly improved grip strength, ROM, and pain levels across all patients (p < 0.05). Patients with lunarectomy showed greater improvements in combined flexion-extension ROM (p = 0.001), grip strength (p = 0.0023), MMWS (p = 0.0033), and pain reduction (p = 0.037) compared to those with lunate preservation. Fusion was achieved in 92% of patients, with no significant differences in radiological outcomes between the two groups.

Conclusion

SCF is an effective intervention for Stage III KD, offering pain relief and functional improvement. Lunarectomy may provide advantages over lunate preservation, particularly in terms of pain reduction and ROM, making it a considerable option for the surgical management of advanced KD.

Level of evidence

level IV.