Experience with periprosthetic infection after limb salvage surgery for patients with osteosarcoma.

Background: The rate of postoperative infection developing is higher after limb salvage surgery (LSS) following sarcoma resection compared with conventional arthroplasty. The goal of this study is to summarize our experience in management of periprosthetic joint infection (PJI) and the risk factors of early PJI after LSS.

Methods: Between January 2010 and July 2019, 53 patients with osteosarcoma in the lower extremities who encountered periprosthetic infection after segmental tumor endoprosthetic replacement in our center were analyzed. Detailed patient characteristics and therapeutic information were collected from database of our institution or follow-up data and we divided patients according to the interval time between infection and tumor resection (surgery-infection interval) and investigate potential risk factors.

Results: A total of 53 (5.08%) patients were suffered postoperative infection. The average interval between surgery and clinical signs of deep infections are 27.5 days. For the drainage culture, positive results were only presented in 11 patients (20.8%). Almost half of this study's (47.2%) patients underwent a traditional two-stage revision, that was, after the removal of the infected prosthesis, we applied antibiotic-loaded bone cements as a spacer. The mean blood loss during initial implantation surgery and operation time both correlated with interval period between PJI and initial implantation significantly (P = 0.028, P = 0.046). For several patients which infection marker was hardly back to normal after spacer implantation, we conservatively introduced an improved combination of bone cement and prosthesis for the second-stage surgery (5.6%). There were six patients needing re-operation, of which three were due to the aseptic loosening of the prosthesis, one developed periprosthetic infection again, and two patients encountered local recurrence and underwent amputation. Two patients were dead from distal metastasis.

Conclusions: A two-stage revision strategy remains effective and standardized methods for PJI patients. Total operation time and blood loss during LSS of osteosarcoma are the main risk factors of early PJI. For the patients without confirmed eradiation of microorganisms, an improved combination of bone cement and prosthesis applied in the second-stage surgery could achieve satisfied functional and oncologic results.