Flap reconstruction after resection of lower extremity bone tumors: A secondary analysis of the PARITY trial

Endoprosthetic reconstruction for lower extremity bone tumors is associated with a relatively high risk of infection. Although flap reconstruction has been associated with improved postoperative outcomes after tumor surgeries, existing literature has not comprehensively investigated its impact within large, multicenter patient cohorts with granular surgical data.

A secondary analysis of the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial was conducted by incorporating 604 patients who underwent endoprosthetic reconstruction for lower extremity bone tumors. Cohorts with and without flap utilization were compared and balanced using weights derived from entropy balancing. The effect of flap reconstruction on one-year surgical site infection, reoperation, and functional outcomes was assessed using multivariable logistic regression in the balanced cohorts.

Flap reconstruction was incorporated in 83 (13.7%) cases and was associated with tumors of the tibia, longer surgical incision, and large excisions of skin (p<0.05). After balancing the cohorts, flap reconstruction was not associated with surgical site infection (OR: 0.56, 95% CI: 0.30-1.04, p=0.068) but was independently associated with significantly lower odds of reoperation (OR: 0.46, 95% CI: 0.26-0.82, p=0.0083). Cases with flap reconstruction were associated with lower absolute risks of reoperations for soft tissue coverage (6.0% vs. 11.9%) and deep infection (18.1% vs. 27.0%). Flap reconstruction was not associated with different functional outcomes after one year (p>0.05).

In this secondary analysis of a randomized controlled trial, flap reconstruction was associated with reduced risk for reoperation in balanced cohorts. Flap coverage may prevent deep infections and hardware exposure following endoprosthetic reconstruction.