Effect of Fixation Type and Bone Graft on Tarsometatarsal Fusion

Abstract

Background: End-stage tarsometatarsal (TMT) arthritis is commonly treated with arthrodesis of involved joints. Fixation hardware can consist of varying combinations of screws, plates, and staples with or without supplemental bone graft. There are limited data to demonstrate either superiority of a given fixation method or the impact of bone graft on fusion rates. The purpose of this study, therefore, was to determine whether nonunion rates after TMT arthrodesis were influenced by either the use of screw vs plate fixation or the addition of bone graft vs no bone graft. Methods: All patients older than 18 years undergoing arthrodesis for TMT arthritis between July 1991 and July 2016 were identified retrospectively. Exclusion criteria included less than 12 months follow-up, prior midfoot surgery, any added procedure beyond TMT arthrodesis using plates or screws, and acute foot trauma. All patients with radiographic or clinical nonunion, including those requiring revision surgery, were identified. Demographic data and associated risk factors were recorded via chart and radiographic image review. Eighty-eight patients (88 feet, mean follow-up: 75.1 ± 51.4; range, 12-179), with a total of 189 joints and who met enrollment criteria were treated by 9 different surgeons with arthrodesis. Results: The overall nonunion rate was 11.4%. Significant independent risk factors associated with nonunion were (1) arthrodesis using plate fixation with all screws through the plate (odds ratio [OR], 6.2; 95% confidence interval [CI], 1.8-21.3; P = .004), (2) smoking during the perioperative period (OR, 7.9; 95% CI, 2.1-30.2; P = .002), and (3) postoperative nonanatomic alignment (OR, 11.2; 95% CI, 2.1-60.8; P = .005). Bone graft utilization was found to significantly lower the rate of nonunion (OR, 0.2; 95% CI, 0.1-0.6; P = .006). Conclusion: Isolated plate fixation, smoking, and postoperative nonanatomic alignment appear to significantly increase the rate of nonunion among patients undergoing TMT arthrodesis for midfoot arthritis. Concomitant use of autogenous bone graft significantly decreased this risk. Level of Evidence: Level III, retrospective comparative study.