Association of Tarsometatarsal Joint Slippage With Distal Screw Removal After Third-Generation Minimally Invasive Bunion Surgery: A Retrospective Controlled Study.
TL;DR
Increased TMT slippage and incomplete correction of deformity (lower HVA/IMA change) were associated with higher ROH likelihood, raising the possibility that postoperative TMT slippage may be associated with symptomatic distal screw removal, although causation cannot be inferred.
Abstract
BackgroundFollowing Minimally Invasive Bunionectomy (MISB), some patients undergo the removal of hardware (ROH) due to medial-sided pain near the distal metatarsal screw site. Medial pain following MISB has been attributed to multiple factors, including hardware prominence, residual medial bony prominence, and construct-specific considerations. One potential radiographic finding observed postoperatively is medial translation of the first metatarsal base at the tarsometatarsal (TMT) joint, referred to here as "TMT slippage." This study investigated the association between postoperative TMT slippage and subsequent ROH following MISB.MethodsA retrospective analysis identified 38 MISB patients with distal screw ROH and a control group of 40 MISB patients without ROH. Pre- and at least 6-month post-operative anteroposterior (AP) radiographs were measured to obtain transverse TMT slippage, distal and midshaft foot width, hallux valgus angle (HVA), and intermetatarsal angle (IMA). Independent samples t-tests and chi-square analyses compared continuous and categorical characteristics, respectively. Multivariable logistic regression modeling identified ROH risk factors.ResultsInterobserver reliability, measured by intraclass correlation coefficients (ICCs), was high for all measurements (ICC > 0.70). The change in TMT slip was significantly higher in the ROH group compared to the control group (+1.39 vs +0.80, P = .004). A greater decrease in distal foot width (narrower distal width postoperatively) was associated with an increased ROH likelihood (odds ratio [OR] = 0.76), while smaller reductions in HVA and IMA were linked to a higher ROH likelihood (OR = 1.12 and 1.42, respectively). Notably, a larger increase in TMT slip correlated with the highest likelihood of ROH (OR = 2.87).ConclusionWhile midfoot widening was not significantly different between groups, increased TMT slippage and incomplete correction of deformity (lower HVA/IMA change) were associated with higher ROH likelihood. These findings raise the possibility that postoperative TMT slippage may be associated with symptomatic distal screw removal, although causation cannot be inferred.Level of Evidence:Level III, comparative series.