Revision Total Knee Arthroplasty Using the PFC Sigma Knee System

PURPOSE: We wanted to analyze the causes of revision and the clinical and radiographic results after revision total knee arthroplasty. MATERIALS AND METHODS: Thirty-eight knees in 34 patients underwent revision total knee arthroplasty using the PFC(R) Sigma revision system between March 1999 and May 2005. The average patient age was 71.2 years, and the average follow-up period was 6 years 7 months (range: 4 years~10 years 2 months). We evaluated the time interval between the primary and revision arthroplasty and the causes of revision. The clinical outcomes were assessed using the knee score and the functional score of the Knee Society Scoring system (KSS system), and the radiographic measurements were assessed using the roentgenographic method of the American Knee Society. RESULTS: The mean interval between primary and revision arthroplasty was 6 years 3 months. The causes of revision included 25 cases of aseptic loosening and osteolysis, 7 cases of infection, 3 cases of joint stiffness and 3 cases of polyethylene problems. At the follow up, the mean preoperative knee and functional scores improved from 45.1 points to 84.5 and 37.2 to 78.2, respectively. Radiographycally, the average femorotibial angle was corrected from 2.2degrees in valgus to 6.5degrees. The radiolucency score was below 4 in all the cases. The complications after revision arthroplasty were 2 cases of superficial infection and 1 case of wound dehiscence with a skin defect. CONCLUSION: The main causes of revision arthroplasty were aseptic loosening and osteolysis. Satisfactory results were obtained using the posterior cruciate ligament and substituting the PFC(R) Sigma knee system with appropriately selected metal augmentation and an allograft. This study showed favorable results on long term follow-up.

Comparison of Posterior Cruciate Retaining & Substituting Total Knee Arthroplasty in Varus Deformity of Knee

PURPOSE: To evaluate the effect of posterior cruciate ligament retaining total knee arthroplasty on its clinical results in patients with varus deformity. MATERIALS AND METHODS: We analyzed clinical and radiologic results of the 61 cases (39 patients) with varus deformity more than 15 degrees retrospectively. The average follow up period was 6.1 years (range, 5~8 years old). The cases were divided into posterior cruciate ligament retaining group A (42 cases) and substituted group B (19 cases). RESULTS: There was no statistically significant difference between two groups in Knee Society knee score (A group: 88.1, B group: 88.9), functional score (A group: 79.3, B group: 75.6) activity level (A group: 67.5, B group: 62.5), flexion contracture (A group: 4.5 degree, B group: 4.9 degree), tibiofemoral angle (A group: 4.7 degree, B group: 5.2 degree) and roentgenographic findings. Patients with PCL retaining knees showed significantly increased activity levels in going up and down stairs, and walking. CONCLUSION: It is considered that the preservation of the posterior cruciate ligament is better than the substitution of the ligament if technical problems are solved.

Moderate to Severe Varus Deformity in Total Knee Arthroplasty: PFC Sigma Fixed Bearing Versus Rotating Platform / 대한정형외과학회잡지

PURPOSE: To compare the performance of a fixed bearing with a PFC Sigma with that of a rotating platform in a total knee arthroplasty performed on patients with a moderate to severe varus deformity. MATERIALS AND METHODS: Among the patients who had received a total knee arthroplasty with either a PFC sigma fixed bearing or a rotating platform between October 1998 to June 2002, 77 cases (53 patients) with a > 15degrees varus deformity were examined. The surgery time and the clinical ratings and the radiographic images for each patient were investigated. RESULTS: There were no significant differences in the knee score, functional score, activity level, or radiological findings. There were seven cases where friction sounds were produced from the insertions in the rotating platform whilst walking and there were three cases of lateral instability. CONCLUSION: The PFC sigma fixed bearing was more effective for stabilizing the knees with a moderate to severe varus deformity because the rotating platform had a friction sound from the insertions while walking and lateral instability.

Cemented Total Knee Arthroplasty with Posterior Cruciate Ligament Retention: The Comparision of Rheumatoid Arthritis with Osteoarthritis

PURPOSE: To analyze the clinical and roentgenographic results of rheumatoid arthritis and osteoarthritis after cemented total knee arthroplasty with posterior cruciate retention. MATERIALS AND METHODS: Since 1989, 53 cases of rheumatoid arthritis and 454 cases of osteoarthritis were followed up for average 7.3 years(range 5-14 years) after cemented total knee arthroplasty with posterior cruciate retention. RESULTS: There was no statistically difference in KSS knee score(A: 88.5, B: 92.2), functional score(A: 73.2, B: 79.3), activity level(A: 76, B: 80), flexion contracture(A: 4.5 degree, B: 4.3 degree), tibiofemoral angle(A: 4.8 degree, B: 4.7 degree) and roentgenographic findings. There were hyperextension of 4 cases in group A and 3 cases in group B, but instability was not found. CONCLUSION: There was no significant difference in clinical and radiological results between the osteoarthritic and rheumatoid arthritic group after cemented TKR with PCL retention. Therefore, cemented TKR with PCL retention could be used as a valuable method in treating rheumatoid arthritis.