Development and External Validation of a Prognostic Staging System for Predicting Wound Complication after Internal Hemipelvectomy: An International Multicenter Study

BACKGROUND: Internal hemipelvectomy is a challenging procedure often complicated by wound healing issues. To guide surgical planning and reduce the risk of wound complications, we developed and validated a preoperative risk-stratification model. STUDY DESIGN: We reviewed clinical, surgical, and pathologic data from 411 patients who underwent en bloc internal hemipelvectomy for malignant pelvic tumors between 1996 and 2018. The sample included a training set (N = 123) from a US tertiary hospital and a validation set (N = 288) from centers in Canada and The Netherlands. Using logistic regression, we identified key predictors of wound complications requiring surgical intervention and developed a risk-scoring system that incorporates Enneking-Dunham resection type and tumor anatomic compartment extension. Patients were stratified into 3 risk categories: low (0 to 8 points), intermediate (9 to 13 points), and high (greater than or equal to 14 points). RESULTS: Wound complications requiring surgery occurred in 34% of the training cohort and 35% of the validation cohort. In the training cohort, rates of wound complications were 7.4%, 40%, and 67% in the low-, intermediate-, and high-risk groups, respectively (p < 0.001); rates were similar in the validation cohort (7.1%, 32%, and 49%; p < 0.001). The risk model demonstrated fair-to-good discriminative performance; the areas under the receiver operating characteristic curves were 0.83 (training cohort) and 0.71 (validation cohort) despite heterogeneity in tumor histology, reconstruction techniques, and perioperative management. CONCLUSIONS: We present the first externally validated prognostic staging system for predicting wound complications after internal hemipelvectomy. The model is simple, reproducible, and clinically applicable, allowing surgeons to preoperatively identify high-risk patients who may benefit from modified surgical approaches or prophylactic soft-tissue reconstruction. Further prospective studies are warranted to optimize management strategies for intermediate- and high-risk patients.