A systematic review of mechanical stabilization by screw fixation without bone grafting in the management of stable scaphoid non-union.

Introduction: Sixty percent of all carpal fractures affect the scaphoid bone, with an annual incidence of 4.3/10,000. Displacement and instability are the main risk factors for non-union, but missed diagnosis, location of fracture and poor blood supply are also risk factors. Non-union is defined as non-healed fracture on radiographs 6 months after the injury and this can lead to degenerative wrist arthritis. Treatment options vary from internal fixation with bone grafting to salvage procedures including arthrodesis of carpals. We aimed to determine the effectiveness of screw fixation without bone grafting for the treatment of stable well-aligned scaphoid non-union.

Methods: In this systematic review, MEDLINE, Science Direct, Web of Science and CINHAL were searched from inception to May 2019. All clinical studies that examined the functional and radiological outcomes of screw fixation without bone grafting to treat stable scaphoid non-union were included.

Results: 838 articles were retained of which 6 case series, describing 95 patients who had undergone scaphoid non-union fixation without bone grafting, were included. Favourable functional outcomes were reported by the 6 included studies using validated functional outcome measures ROM improved to weighted mean of 67.5° (±13°) and 62.12° (±13°) for flexion and extension respectively. The fracture had united in 91 out of 95 participants with a union rate of 95.7% (95%, CI 89.5 to 98.8) and the weighted mean time to union was 3.8 (±1.5) months.

Conclusion: Rigid screw fixation without bone grafting can be suggested for the treatment of selected well aligned scaphoid nonunions to achieve healing and good functional outcomes. However, adequately powered clinical studies with good methodology are essential to draw an accurate conclusion.