Aims

The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design.

Introduction: The clinical results of 164 cementless Low Contact Stress Rotating Platform Knee Replacements are reported at a maximum follow-up of 15 years Revision for any reason but infection was considered as a failure. Methods: 164 cementless TKA were assessed. Findings: Radiological evaluation showed stable fixation of all components, but in 7 knees (4.26%) significant osteolysis had occurred. Four knees had osteolysis beneath a loose tibial component after 10.2 years from the index surgery and revised to a cemented long-stem tibial component. Three knees were treated with bearing exchange and with bone graft in the tibial lytic region at an average 11.4 years from the index surgery. One cementless rotating-bearing patella (0.60%) required revision. Conclusion: The survivorship of cementless knee replacements using rotating platform with end points of revision for any mechanical reason but infection was 96.34% at 15 years. However, complications due to an increased incidence of osteolysis after 10 years follow-up have been also identified

In 2000 the Nuffield and Rotaglide Knee prostheses were combined into the Rotaglide+ system. This allowed a choice of either mobile or fixed meniscal bearing in the same prosthesis. Between 1988 and 2000 460 primary Nuffield knee prostheses were implanted and between September 2000 and September 2005 185 primary Rotaglide+ prostheses have been used. A Prospective review using a pain score, range of movement, time walked, and the American Knee Surgeons score was performed. The Rotaglide+ cases have been age, sex, and diagnosis matched with 185 Nuffield knees. All prostheses have been implanted by one surgical team, using the same technique and the same instruments. All are inserted cementless with patella replacement if possible. Statistical analysis was performed on the first 5 years of follow-up for both sets of prostheses (STATA). The Nuffield prostheses was significantly better at relieving pain in all years post-operatively. The Rota-glide+ has a slightly better range of flexion, but this is significant only at the 2nd year. There is no significant difference in the walking time, and the AKSS is significantly better for the Nuffield prosthesis only at the first year. Statistical significance is difficult to obtain in years 4 and 5 due to the small numbers of Rotaglide+ prosthe-ses that have reached this stage of review. Conclusion: A change in design has not improved the short term outcome of these prostheses, and may have worsened the results especially in terms of pain relief. This could be due to the change in stem size and the tibial fins. It is recommended that all changes in prostheses should undergo a limited controlled clinical trial before being released onto the open market