A two-stage retention débridement protocol for acute periprosthetic joint infections.

BACKGROUND: Due to the historically poor infection control rates with débridement and component retention for acute periprosthetic infections we developed a new approach for treating acute periprosthetic total joint infections: initial débridement with prosthesis retention and placement of antibiotic-impregnated cement beads followed by a second débridement within 7 days, at which time the beads are removed and new modular parts inserted. Intravenous antibiotics were used for 6 weeks followed by oral antibiotics. Depending on the clinical situation, antibiotics are discontinued or in selected patients continued indefinitely. QUESTIONS/PURPOSES: We determined the ability of this two-stage débridement to control infection. METHODS: We retrospectively reviewed the charts of 20 patients who underwent this technique; 2 had postoperative and 18 had hematogenous infections. The primary outcome measure was the infection control. The minimum followup was 1 year (mean, 3.5 years; range, 1.2-7.5 years). RESULTS: Two of the 20 patients had persistent infection. There were no failures in the acute postoperative group (0 of 2) and two of 18 in the acute hematogenous group. Of the 18 patients without evidence of persistent infection, 10 were no longer on antibiotics at the most recent followup and eight were treated with long-term antibiotics due to compromised host status. CONCLUSIONS: The control of infection in 18 of 20 patients using this technique compares favorably with historical success rates, which range from 24% to 100%. Further research is required to analyze the individual contribution of débridement technique, the use of serial débridements, local depot antibiotics, and combination antibiotic therapy on short-term infection control rates and the long-term persistent control of periprosthetic infection. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of level of evidence.

TP53 mutations and outcome in osteosarcoma: a prospective, multicenter study.

PURPOSE: Mutations of the TP53 gene have been associated with resistance to chemotherapy as well as poor prognosis in many different malignancies. This is the first prospective study of the prognostic value of somatic TP53 mutations in patients with newly diagnosed extremity osteosarcoma. PATIENTS AND METHODS: One hundred ninety-six patients with high-grade, nonmetastatic osteosarcoma of the extremities were enrolled from seven tertiary care institutions and observed prospectively for tumor recurrence (median follow-up duration, 44 months). All patients received neoadjuvant or adjuvant chemotherapy and surgery. Tumors were analyzed for the presence of TP53 mutations by polymerase chain reaction single-strand conformation polymorphism analysis and direct DNA sequencing. The association of the status of the TP53 gene with the risk of systemic recurrence was examined using survival analyses with traditional and histologic markers as prognostic factors. RESULTS: Patient age was the only factor that varied with TP53 gene status (P = .05). No relationship was identified between TP53 status and systemic relapse (relative risk, 1.24; P = .41). Analyses based on missense or nonsense mutations gave similar results (P > .10). In multivariate analysis, large (> 9 cm) tumor size (relative risk, 1.9; P = .006) and poor histologic response (< or = 90% necrosis) to chemotherapy (relative risk, 2.14; P = .02) were the only significant independent predictors of systemic outcome. CONCLUSION: We found no evidence that TP53 mutations predict for development of metastases in patients with high-grade osteosarcoma. Identification of other genes that influence chemotherapy response and clinical outcome in osteosarcoma is needed to facilitate further improvements in patient outcomes.