Total Knee Arthroplasty in Patients with Retention of Prior Hardware Material: What is the Outcome?

Background: There is an information gap in literature regarding postoperative outcome of total knee arthroplasty (TKA)in patients with hardware in-situ from the previous knee surgery. The present study aims to evaluate impact of retainedhardware on short-term outcome of TKA patients.Methods: Perioperative radiographs of patients who had undergone TKA between 2007 and 2012 were reviewedand patients in whom partial or complete retention of hardware was evident after TKA were included. These patientswere matched in 1 to 2 ratio based on age (+/- 2 years), gender, surgeon and year of surgery to a group of patientsthat underwent primary TKA without hardware in the affected knee. The average follow up of these patients was 43.45(range 12-155.2) months. Complication rates were compared between the two groups using statistical tests that tookinto account the matched data structure.Results: We included a total of 55 cases and 110 controls. The incidence of complications was higher, although notall statistically significant, in the case group. Only mechanical complications were significantly different in the casesgroup (5.5% versus 0%, P=0.01). Time to event analysis using the mixed-effects Cox model didn’t show a statisticallysignificant difference between two groups for various outcomes.Conclusion: Presence of retained hardware around the knee may predispose the patient to a higher rate ofcomplications particularly mechanical complications of the implant after TKA. Further studies are required to investigateimpact of retained hardware around the knee in patients undergoing TKA.