[Knee joint prosthesis implantation after fractures of the head of the tibia. Intermediate term results of a cohort analysis].

A significant number of patients with operated tibial plateau fractures develop osteoarthritis and require total knee arthroplasty. In cases of primary osteoarthritis the results are generally good. However, it is not known whether patients with post-traumatic osteoarthritis obtain comparably favorable results. In a retrospective study we analyzed 72 patients who had undergone a self-aligning (SAL) total knee arthroplasty. Ten patients received arthroplasty due to sequelae of a tibial head fracture (group I). The median time to follow-up in this group was 30 months. Clinical and radiological evaluation was based on the Knee Society Clinical Rating System. The score comprises pain, range of motion, stability, and function. We defined the axis and possible loosening by radiological examination. For comparative descriptive statistics, a cohort of patients was chosen who had received an arthroplasty because of primary gonarthrosis (group II, 76 arthroplasties in 62 patients). The median time to follow-up in this group was 46.5 months. Three patients in group I underwent revision surgery, four patients displayed severe functional deficits and pain, and one patient had a varus deformity with good clinical function. This corresponded to an early complication rate of 27% and a late complication rate of 36%; a relevant instability or loosening of the components did not occur in this group. In group II the incidence of early complications was 10%. The patients in group I reached a mean value of 153 points using the rating system vs 167 points in group II. Analyzing the clinical parameters of the score, we found that patients in group I experienced significantly more pain, thereby affecting functions of daily living, such as walking and climbing stairs. Because of the small number of patients in group I, conclusions can only be drawn to a limited extent. However, we saw that these patients displayed a higher incidence of complications and performed less well. This has to be taken into consideration and discussed prior to surgery.