[Long-term results of surgical treatment of scaphoid non union: influence of the correction of dorsal intercalated segment instability]

Treatment of scaphoid nonunion by arthroscopic cancellous bone grafting

INTRODUCTION

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.

MATERIAL AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

LEVEL OF EVIDENCE

III.

Correction of residual humpback deformity after arthroscopic treatment of scaphoid non-union

BACKGROUND

The aim of this study was to assess residual humpback deformity after arthroscopic treatment of scaphoid non-union.

MATERIAL AND METHOD

We reviewed the medical records of 47 patients with scaphoid non-union who underwent arthroscopic treatment between 2012 and 2018. Patients who did not receive an intraoperative bone graft were excluded (10 patients), as were those who did not achieve bone union (three patients). The radiographic assessment consisted of pre- and postoperative radiographs and CT-scans.

RESULTS

The radiolunate angle, scapholunate angle and Youm index were measured. At the final follow-up, the scapholunate angle was 54±8̊ (36-80̊) and the radiolunate angle was 11±7̊ (2-45̊). The scapholunate angle was significantly different between the preoperative measurement and the last follow-up; however, the radiolunate angle and Youm index did not change significantly.

CONCLUSION

Our study found that arthroscopic treatment of scaphoid non-union with a cancellous bone graft taken from the distal radius results corrects the humpback deformity.

LEVEL OF EVIDENCE

IV.

Arthroscopic treatment of scaphoid nonunion with humpback deformity and DISI with corticocancellous bone grafting: Technical note

For two decades, scaphoid nonunion has been treated arthroscopically. However, compressed cancellous bone graft does not have the same mechanical properties as corticocancellous bone graft for reducing the scaphoid humpback deformity and DISI tilt. Here, we describe an arthroscopic technique to treat Alnot stage IIB scaphoid nonunion. We treated a 27-year-old male patient for scaphoid waist nonunion with humpback deformity and DISI. A 8×8×10 mm cylindrical corticocancellous bone graft was harvested from the dorsal aspect of the radius using a single-use osteochondral autograft transfer system (OATS®, Arthrex Inc., Naples, USA). It was inserted in the nonunion site through an arthroscopic volar approach. Bone union was obtained at 3 months with lasting correction of the scaphoid humpback deformity and DISI. The functional result at 6 months was excellent. There were no complications. Scaphoid nonunion with humpback deformity and DISI may be treated arthroscopically with a corticocancellous bone graft.