Mid-term Results of Total Knee Arthroplasty Using PFC Sigma RP-F

PURPOSE: We compared the mid-term results after total knee arthroplasty (TKA) using PFC Sigma RP-F mobile model with PFC Sigma PS fixed model. MATERIALS AND METHODS: We analyzed 45 knees that underwent TKA with PFC Sigma RP-Fn (study group) and 45 knees with PFC Sigma PS (control group). The mean follow-up period was 65 months (range, 60-69 months). The evaluation system of the American knee society was used for clinical and radiological assessment. Also, the maximal knee flexion angle was assessed. RESULTS: The mean maximum flexion angle in the study group (135degrees) was greater than that in the control group (125degrees) at the early post-operation & final follow-up period (p=0.033). The range of motion (ROM) in the study group was recovered earlier at the postoperative 6 months, and ROM gain was improved to a greater extent at the final follow-up period (p=0.039). The knee score and function score and radiographic evaluation were no difference between the two groups (p>0.05) at the final follow-up. The two cases of radiolucency in posterior condyle and medial tibial plateau and one case of patellar elongation were seen in the study group. CONCLUSIONS: The PFC Sigma RP-F mobile system appears to facilitate greater maximum flexion angle and ROM gain with two cases of radiolucent line.

Comparative Study of the Postoperative Maximal Flexion Angle in PCL-substituting TKAs: Conventional PS vs. High-flex PS / 대한정형외과학회잡지

PURPOSE: This study was performed to compare the postoperative maximal flexion angle (MFA) of standard PCL-substituting (PS) prosthesis with that of high-flexion PS prosthesis after total knee arthroplasty (TKA). MATERIALS AND METHODS: A total of 81 patients (133 knees) were enrolled in this study. Sixty-eight primary bilateral TKAs were performed in 34 consecutive patients. The bilateral TKAs were performed in a staged sequential manner, with a standard PS prosthesis in one knee and a high-flexion PS prosthesis in the contralateral knee. We also analyzed the results of another 47 patients as several control groups, and this consisted of standard or high-flexion PS total knee prostheses in the bilateral TKAs, and standard or high-flexion PS total knee prostheses in the unilateral TKAs. The patients were clinically assessed with the Knee Society scoring system and the MFA was measured with a goniometer. RESULTS: At the last follow up, the mean postoperative MFA of the 34 patients operated with the combination of different prostheses was 131.6+/-10.4degrees for high-flexion prosthesis side and 131.6+/-9.5degrees for standard prosthesis side respectively. There was no statistically significant difference. On comparing with the results of the 47 patients in the control group, no statistically significant difference in the mean postoperative MFA was found between the groups. CONCLUSION: We found no significant differences between the high-flexion PS prosthesis and the standard PS prosthesis in the postoperative MFA.