The purpose of this study is to present the clinical and radiological evaluation of 632 resurfacing total knee arthroplasties of Foundation-Solution type, performed in 550 patients (437 women and 113 men), from 1994 to 2003. In the majority of cases (569 knees) the operation was performed because of degenerative osteoarthritis. Cement-free implantation was performed in 209, cemented in 117 and hybrid implantation in 306 procedures. We were able to retrospectively review 442 (80.4%) of the patients (498 knees), for a follow-up time of 6 months to 10 years. The Knee Insall Rating Scale was improved from 60 points (34–70) preoperatively, to 92 points (74–100) postoperatively. The range of flexion at the latest follow-up was between 75 to 130 degrees (mean 98 degrees). Extension lag more than 10 degrees was found in 3 patients (0.68%). The radiological evaluation was performed according to Knee Society Röentgenographic Evaluation and Scoring System. Partial periprothetic radiolucent lines (<
1mm) were observed in 35 knees (7%), with no statistical significant difference between the three groups and no progression during the follow-up. No further clinical and radiological evidence of mechanical failure and no significant loss of the mechanical axis were noticed. There was a case of fatal pulmonary embolism, and a case of peroneal nerve palsy that fully recovered. Three knees were revised as a result of septic loosening.