Patellar subsidence in heavy patients undergoing bilateral knee arthroplasty

A retrospective review of 40 patients undergoing simultaneous bilateral total knee replacement was undertaken to investigate the link between patient body weight and patellar subsidence. Of the 40 patients, three (five knees) had collapse or fracture of the patellar bone and four (five knees) had developed radiolucent lines around the patellar implant. None of these patients were symptomatic and their Knee Society and Oxford functional scores were satisfactory. All of the seven patients had body weights significantly greater than the average for the series.