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BACKGROUND: Megaprostheses contain many more modular components than conventional total hip and knee arthroplasty, which may lead to higher serum levels of metal ions. The aim of this study was to determine serum concentrations of titanium, chromium, and cobalt ions in cancer patients after limb salvage surgery with a megaprosthesis. METHODS: A retrospective, descriptive cohort analysis consisting of patients who underwent cancer-related limb salvage surgery with a megaprosthesis at our hospital between 2010 and 2020 was conducted. Baseline and follow-up data were extracted from clinical and surgical records. Blood samples were prospectively obtained. Descriptive statistics were used for the analysis. RESULTS: A total of 71 patients underwent limb salvage surgery during the study period. Of these, 22 (10 women, 12 men) were included in the study. The mean age was 52 years (range, 21 to 80). Most cases (n = 16; 72.7%) involved the femur. Most patients (n = 14, 63.6%) underwent total knee megaprosthesis surgery. Implant revision surgery was required in 45% of cases (n = 10), with a mean interval of 4.32 years between the initial and revision surgeries. The mean follow-up time after revision surgery was 4.05 years. High levels of chromium were observed in 22.7% of patients (n = 5). High cobalt levels were found in 68.2% (n = 15) of patients, with toxic levels in 9.1% (n = 2). Titanium levels were high in 77.3% (n = 17) of cases and toxic in 22.7% (n = 5). Postoperative chemotherapy was significantly associated with titanium levels (P = .017). No correlation was observed between metal ion levels and time from primary or revision surgery or time from the first to revision surgery. CONCLUSIONS: This study shows that cancer-related limb salvage surgery with megaprosthesis is associated with metal ion levels that exceed established safe thresholds. Compared to conventional hip arthroplasty, a higher proportion of the patients in this cohort presented elevated levels of metal ions. LEVEL OF EVIDENCE: III.
RESUMO
BACKGROUND: Reference centers (RCs) are a key point for improving the survival of patients with soft-tissue sarcomas (STS). The aim of this study was to evaluate selected items in the management of patients with STS, comparing results between RC and local hospitals (LHs). MATERIALS AND METHODS: Diagnostic and therapeutic data from patients diagnosed between January 2004 and December 2011 were collected. Correlation with outcome was performed. RESULTS: A total of 622 sarcomas were analyzed, with a median follow-up of 40 months. Imaging of primary tumor preoperatively (yes vs. no) correlated with a higher probability of free surgical margins (77.4% versus 53.7%; p = .006). The provenance of the biopsy (RC vs. LH) significantly affected relapse-free survival (RFS; 3-year RFS 66% vs. 46%, respectively; p = .019). Likewise, 3-year RFS was significantly worse in cases with infiltrated (55.6%) or unknown (43.4%) microscopic surgical margins compared with free margins (63.6%; p < .001). Patients managed by RCs had a better 3-year overall survival compared with those managed by LHs (82% vs. 70.4%, respectively; p = .003). Perioperative chemotherapy in high-risk STS, more frequently administered in RCs than in LHs, resulted in significantly better 3-year RFS (66% vs. 44%; p = .011). In addition, patients with stage IV disease treated in RCs survived significantly longer compared with those in LHs (30.4 months vs. 18.5 months; p = .036). CONCLUSION: Our series indicate that selected quality-of-care items were accomplished better by RCs over LHs, all with significant prognostic value in patients with STS. Early referral to an RC should be mandatory if the aim is to improve the survival of patients with STS. IMPLICATIONS FOR PRACTICE: This prospective study in patients diagnosed with soft-tissue sarcoma shows the prognostic impact of reference centers in the management of these patients. The magnitude of this impact encompasses all steps of the process, from the initial management (performing diagnostic biopsy) to the advanced disease setting. This is the first prospective evidence showing improvement in outcomes of patients with metastatic disease when they are managed in centers with expertise. This study provides extra data supporting referral of patients with sarcoma to reference centers.