Functional outcomes of reconstructive flap surgery for soft tissue sarcoma: Long-term outcomes of functional restoration using innervated muscle transplantation

Functional outcomes associated with prognostic factors and innervated muscle transplantation after wide soft tissue sarcoma resection remain unclear. We retrospectively examined the functional outcomes of reconstructive flap surgery for soft tissue sarcoma. Twenty patients underwent innervated muscle transplantation with pedicled or free flaps for functional reconstruction of resected muscles. Thirteen latissimus dorsi muscles and one vastus lateralis muscle combined with an anterolateral thigh flap were transferred as free flaps using the epi-perineural suture technique. Six latissimus dorsi muscles were transferred as pedicled flaps with neural continuity. Postoperative functional outcomes were assessed using the Musculoskeletal Tumor Society (MSTS) scores for the upper and lower extremities of 22 and 24 patients, respectively. The mean MSTS score for all patients was 82.3 at 12 months postoperatively. The mean scores for patients who underwent reconstruction with pedicled and free flaps were 89.2 and 77.1, respectively. The MSTS scores for the lower extremity, tumor size ≥5 cm, and free flap reconstruction were significantly lower than those for the upper extremity, tumor size <5 cm, and pedicled flap reconstruction (P = 0.02, 0.37, and 0.008, respectively). The postoperative MSTS score for innervated muscle transplantation was 76.7 at 12 months and was significantly higher (83.7) at 24 months (P = 0.003). Functional outcomes were significantly associated with tumor location, tumor size, and reconstructive flap type based on the MSTS scores. Innervated muscle transplantation improved functional outcomes at 24 months postoperatively via sufficient recovery of the innervated muscle, not the compensatory recovery of the remaining muscle.