Risk factors for delayed bone union in opening wedge high tibial osteotomy

Abstract

Objectives: The purpose of this study was to investigate the relationship between patient demographics and potential intraoperative factors and delayed bone union in opening wedge high tibial osteotomy (OWHTO).

Patients and methods: A retrospective review of 65 patients (37 females, 28 males; mean age: 60.1±10.1 years; range, 44 to 77 years) who underwent OWHTO using an angle-stable implant with beta-tricalcium phosphate gap filling between September 2016 and October 2019 was conducted. The osteotomy site was divided into five zones from the lateral hinge on anteroposterior radiographs, and we defined the zone in which bone healing was observed. The bone union area was assessed according to this definition at three, six, nine, and 12 months after surgery, and bone union was defined as union at the fourth zone or greater. A generalized estimating equations approach was employed to investigate longitudinal data pertaining to bone union area as a dependent variable. In addition, the association of bone union at six months postoperatively and predictors were evaluated using cross-sectional statistical methods. The categorical predictors included in the models were smoking, diabetes, hinge fracture, and autologous osteophyte grafting. The continuous variables included in the models were age, body mass index, opening gap width, and plate position.

Results: Smoking (odds ratio [OR]=0.478, p<0.01), large opening gap width (OR=0.941, p=0.014), and anterior plate placement (OR=0.971, p<0.01) were significantly associated with decreased bone union area. Union rate at six months in smokers was significantly lower compared to nonsmokers (16.6% and 67.8%, respectively; OR=0.10, p=0.023). Area under the curve in the receiver operating characteristic analysis for bone union at six months was 0.60 for gap width and 0.63 for plate placement.

Conclusion: Smoking, large opening gap width, and anterior plate placement are risk factors for delayed bone union after OWHTO. Surgeons should avoid anterior placement of the plate and carefully consider other options for smokers and those who require a large correction.

Citation: Araya N, Koga H, Nakagawa Y, Shioda M, Ozeki N, Kohno Y, et al. Risk factors for delayed bone union in opening wedge high tibial osteotomy. Jt Dis Relat Surg 2024;35(3):546-553. doi: 10.52312/jdrs.2024.1636.

The study protocol was approved by the Tokyo Medical and Dental University Ethics Committee (date: April 03, 2015, no: M2000-2054-01). The study was conducted in accordance with the principles of the Declaration of Helsinki.

A written informed consent was obtained from each patient.

Analyzed the data and drafted the manuscript: N.A.; Designed the initial plan, conducted the study and edited the manuscript: H.K.; Designed the initial plan: Y.N., M.S.; Collected the data: T.O., N.O., Y.K., T.N., I.S.; Designed the initial plan, conducted the study and completed the final manuscript: H.K. All authors read and approved the final manuscript.

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

The authors received no financial support for the research and/or authorship of this article.

The data that support the findings of this study are available from the corresponding author upon reasonable request.