Computed Tomography Detects Hinge Fractures After Medial Opening Wedge High Tibial Osteotomy: A Systematic Review

Abstract

Purpose: To quantify the increased detection rate of lateral hinge fractures (LHFs) owing to additional computed tomography (CT), determine factors associated with LHFs, and compare radiologic and clinical outcomes of LHFs after medial opening wedge biplanar high tibial osteotomy (MOW-HTO).

Methods: The MEDLINE, Embase, Cochrane Library, and Web of Science databases were systematically searched to identify studies reporting the incidence of LHFs detected using additional CT, showing radiologic factors, or comparing radiologic and clinical outcomes between LHFs and non-LHFs after MOW-HTO. Subgroup analyses were performed to compare stable and unstable LHFs. Two reviewers performed the study screening, risk-of-bias assessment, and data extraction processes.

Results: Eleven studies were included in this review. The weighted estimate of the apparent incidence of LHFs in the pooled studies was 24.8%. The weighted estimate of the incidence was increased by 9.9% owing to the use of CT detection, which indicated that approximately 40% of total diagnosed LHFs were missed on plain radiographs or fluoroscopy. The pooled mean opening gap distance ranged from 11.40 to 12.60 mm in the LHF group and from 9.80 to 11.12 mm in the non-LHF group, and the mean difference in the opening gap distance was significantly larger in the LHF group (95% confidence interval, 0.64-1.84 mm; P < .0001). However, no significant differences in correction loss, bone union duration, and clinical outcomes were observed between the LHF and non-LHF groups. Subgroup analyses showed no significant differences between stable and unstable LHFs.

Conclusions: Postoperative CT evaluations increase the detection rate of LHFs compared with plain radiography alone. Furthermore, the opening gap distance was larger in the LHF group than in the non-LHF group, suggesting the need for attention when opening the wedge by more than 11.4 mm. However, the consequences of LHFs after MOW-HTO were not major concerns when proper management was provided.

Level of evidence: Level III, systematic review.