Treatment of scaphoid nonunion by arthroscopic cancellous bone grafting

In order to avoid Scaphoid Nonunion Advanced Collapse (SNAC) type osteoarthritis, which progressively affects the radial and midcarpal joints, several vascularized and non-vascularized grafting techniques have been described. Over the past decade, there has been growing interest in arthroscopic cancellous bone grafts for scaphoid nonunion. The aim of this novel prospective study was to assess the healing rate of scaphoid grafts under arthroscopy, and the prognostic factors for healing.

This prospective study was carried out across 10 centers between September 2019 and April 2021, in patients aged 16 to 65. Scaphoid nonunion grafting was performed arthroscopically. Union was assessed on CT scans and displacement correction angles were measured preoperatively and then at 3 and 6months. We assessed mobility, Jamar wrist strength, functional results as per the Patient Related Wrist Score (PRWE) and the Quick Disabilities of the Arm, Shoulder and Hand (Quick DASH) score. Risk factors for nonunion were assessed.

We included 77 patients with a mean age of 24years (18 to 55years) with a mean time between trauma and treatment of nonunion of 34.8months (6 to 180months). The population was represented by 46 manual workers and 20 were smokers. In 42 cases, the nonunion was proximal, in Schernberg zone I or II. At the last follow-up of 12.9months on average (Standard Deviation: 8.7months), union was achieved in 72 patients (93.5%). The average duration of union was 3.4months (Standard Deviation 1.6). Among the 5 patients who did not heal, grafting was performed in addition to the fixation. We did not identify any contributory factors for nonunion.

This study demonstrated the effectiveness of arthroscopic treatment of scaphoid nonunion with a union rate at least equivalent to pedicled vascularized grafts. Smoking and delayed treatment were no longer considered unfavorable prognostic factors in the context of arthroscopic treatment.

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