Surgical Site Infection in Patients Managed with an Endoprosthesis for the Treatment of Cancer: Evaluation of Patient, Disease, and Index Surgical Factors.

BACKGROUND: Surgical site infection (SSI) after segmental endoprosthetic reconstruction in patients treated for oncologic conditions remains both a devastating and a common complication. The goal of the present study was to identify variables associated with the success or failure of treatment of early SSI following the treatment of a primary bone tumor with use of a segmental endoprosthesis. METHODS: The present study used the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) data set to identify patients who had been diagnosed with an SSI after undergoing endoprosthetic reconstruction of a lower extremity primary bone tumor. The primary outcome of interest in the present study was a dichotomous variable: the success or failure of infection treatment. We defined failure as the inability to eradicate the infection, which we considered as an outcome of amputation or limb retention with chronic antibiotic suppression (>90 days or ongoing therapy at the conclusion of the study). Multivariable models were created with covariates of interest for each of the following: surgery characteristics, cancer treatment-related characteristics, and tumor characteristics. Multivariable testing included variables selected on the basis of known associations with infection or results of the univariable tests. RESULTS: Of the 96 patients who were diagnosed with an SSI, 27 (28%) had successful eradication of the infection and 69 had treatment failure. Baseline and index procedure variables showing significant association with SSI treatment outcome were moderate/large amounts of fascial excision ≥1 cm2) (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.001), use of local muscle/skin graft (OR,11.88 [95% CI, 1.83 to 245.83]; p = 0.031), and use of a deep Hemovac (OR, 0.24 [95% CI, 0.05 to 0.85]; p = 0.041). In the final multivariable model, excision of fascia during primary tumor resection was the only variable with a significant association with treatment outcome (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.018). CONCLUSIONS: The results of this secondary analysis of the PARITY trial data provide further insight into the patient-, disease-, and treatment-specific associations with SSI treatment outcomes, which may help to inform decision-making and management of SSI in patients who have undergone segmental bone reconstruction of the femur or tibia for oncologic indications. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect of chemotherapy on initial compressive osseointegration of tumor endoprostheses.

Chemotherapy has long been suspected of having an adverse effect on bone healing. Massive tumor endoprostheses which achieve osseointegration via compressive force provide a unique model to study the effects of chemotherapy on bone healing. We compared distal femoral bone hypertrophy in patients who received chemotherapy with those who did not. Fifty four patients underwent distal femoral reconstruction with a compression implant. Thirty patients received chemotherapy (Group 1), and 24 did not (Group 2). The group of patients receiving chemotherapy was younger, had lower body mass indices, and had different diagnoses compared to the group of patients not receiving chemotherapy. We used a standardized technique to measure bone growth at the bone-prosthetic interface. The rate of cortical width increase at the bone-prosthetic junction was faster in Group 2 compared to Group 1. Similarly, the increase in cortical width from immediate postop to 3 months and 6 months postop was greater in Group 2 when compared to Group 1. The data suggest chemotherapy administration for musculoskeletal malignancy has a substantial initial adverse effect on bone hypertrophy and a trend towards reduced prosthetic survival. These findings have important implications for the patients with musculoskeletal tumors.