Predictive factors for failure after total knee replacement revision.

PURPOSE: We used the Optetrak Condylar Constrained (CCK) implant, a modular and constrained knee implant as replacement for a failed primary arthroplasty, to assess the survivorship, the complications, the clinical, radiological, and functional situation, and the quality of life of those patients in whom a CCK had been implanted in recent years in order to find predictive pre-operative conditions of survival and clinical outcomes.

METHODS: We performed a retrospective study of 125 CCK implanted between 1999 and 2005. The mean follow-up was nine years (range, seven to 13). Mean age was 73.6 years. A total of 78% of the revised TKA were cemented and 66% were CR. We assessed the pre-operative, the operative and the postoperative conditions studying the medical files of all the patients. In order to study the functional and clinical situation we used the Hospital for Special Surgery (HSS) score and the Knee Society score (KSS), both clinical and functional. We analysed all the X-rays using the Knee Society Roentgenographic evaluation. The quality of life was studied using the Oxford knee score (OKS).

RESULTS: The mean results of the KSS clinical and the KSS functional were 68.24 and 63.85, respectively. There were not any conditions associated with poor results of the knees (p > 0.05). The global survival at 24 months was 92.7%, at 60 months 87.8% and at 96 months it was 87.8%. There were some conditions associated with poor survival of the knees, e.g. patients were younger than 70 years old, rheumatic diseases, kidney faliure, tibial tuberosity osteotomy, PS primary arthroplasty, revision before five years and septic loosening.

CONCLUSIONS: Based on these results there are some pre-operative factors that change the survival of the total knee replacement revision.