A Propensity Score Analysis of Wound Complications Following Revision Total Knee Arthroplasty With Concurrent Flap Coverage

Background: Despite advancements in total knee arthroplasty (TKA), complications requiring revisions still occur. In these cases, flap coverage is often required to achieve a stable soft tissue envelope. This study analyzes wound complications following flap coverage for revision TKAs (rTKA) on a national level. Methods: Patients who underwent rTKA from 2012 to 2020 were identified in the National Surgery Quality Improvement Program database using Current Procedural Terminology codes. The cohort was divided into 2 subgroups: patients who underwent rTKA with a pedicled or free flap and those without a flap. A propensity score was generated from patients’ baseline characteristics. A multivariable logistic regression model adjusting for propensity scoring and wound classification was constructed to assess differences in outcomes. Results: rTKA was performed in 33,922 encounters, 104 (0.3%) of which utilized a flap (99 pedicled and 5 free flaps). Patients who received flaps had poorer preoperative functional status, higher frailty scores, longer operative times, longer hospital stays, and were more likely to have contaminated or dirty/infected wounds. Patients who underwent flaps had higher reoperation rates compared to patients who did not (12.1% vs 3.0%, P < .001). Following propensity score matching, flap coverage was not associated with systemic complications, dehiscence, or superficial or deep surgical site infection. Conclusion: Soft tissue flap coverage was more common in large and infected wounds following TKA. Higher wound infection rates among flap patients are likely due to the complexity of the original wound and possibly lack of adequate source control. Patients undergoing rTKA for infection may benefit from wound optimization before flap reconstruction.