Purpose of the study: The aim of the study was to evaluate our seven-year experience with the anatomic, non-constrained SVL/Beznoska implant for total knee replacement.
Material: A total of 374 cemented total knee replacements, using the SVL/Beznoska implant, were evaluated in 333 patients treated at the First Orthopedic Clinic Charles University in Prague, during a seven-year period. In addition, a patellar replacement was used in five of these patients. Included in the evaluation were also eight non-cemented and hybrid SVL/Beznoska implants used 6 years ago.
Methods: The aim of the study was to evaluate the results in terms of implant function. Therefore, the longevity of implants was assessed by Kaplan-Meier's survival analysis. Another criterion was the flexion achieved. To be able to compare our clinical results involving the SVL/Beznoska implant with other, foreign types of implants, the patients were evaluated on the basis of the New Jersey Orthopaedics Hospital Knee Evaluation System.
Results: The Kaplan-Meier's survival score was evaluated. The mean maximum flexion achieved in the patients with SVL implants was 107 degrees . The evaluation by the New Jersey Orthopaedics Hospital Knee Evaluation System showed excellent outcomes in 269 (72 %) patients, good outcomes in 79 (21 %) patients, satisfactory in 19 (5 %) and poor in 7 (2 %) patients. There was no mechanical failure of the implant, such as break of an implant or dislocation of a PE component. Six infected implants and four aseptic loosenings were recorded. Three patients diagnosed with an infected total knee replacement had been treated for rheumatoid arthritis for a long time. One patient was on dialysis for renal insufficiency and one had erysipelas.
Discussion: The results of our group with the SVL/Beznoska implant were compared with those obtained from the group of 63 patients who underwent total knee arthroplasty with the LCS implant. In these patients, the mean maximum flexion achieved was 105 degrees , and the criteria of the Knee Evaluation System showed excellent outcomes in 81 %, good in 16 % and satisfactory in 3 % of the patients. No unsatisfactory outcome was recorded. Considering the fact that the LCS implant was used only in younger and active patients, the outcomes achieved with the SVL/Beznoska system can be regarded as very good. Of the six patients with infectious complications, three were treated with immunosuppressive therapy for rheumatoid arthritis, one was on dialysis for renal insufficiency and one experienced a flare-up of erysipelas.
Conclusions: The most important outcome of the evaluation of 374 total knee replacements, using the SVL implant carried out at the First Orthopedic Department of the First Faculty of Medicine, Charles University, was the finding of a perfect function of all components in all patients treated. None of the complications occurring in our group was associated with the use of this implant.