Total Knee Replacement Arthroplasty with NexGen(R)-LPS: Minimum 5 Year Follow-up Results / 대한정형외과학회잡지

PURPOSE: One hundred and thirty-six patients who underwent total knee replacement arthroplasty (TKRA) with NexGen(R)-LPS were analyzed for the clinical and radiologic results after a minimum follow-up of 5-years. MATERIALS AND METHODS: This study included 136 patients (209 knees) who underwent TKRA with NexGen(R)-LPS between August 1998 and February 2005 and had a minimum follow-up of 5 years. We evaluated the range of motion (ROM), American Knee Society knee functional scores, radiographic results and complication rates in the study subjects with an average 8.3 years of follow-up (range: 5-11.5 years). We also compared the results of the degenerative arthritis group (195 knees in 129 patients) with those of the rheumatoid arthritis group (14 knees in 7 patients). RESULTS: The mean ROM increased from 107.3degrees to 122degrees at the final follow-up. The flexion contracture also improved from 8.3degrees to 1.2degrees at final follow-up. The knee score improved from 51 to 94.7 at the final follow-up. The functional score improved from 38 to 84.2 (p0.05). Valgus (alpha), varus (beta), flexion (gamma) and the posterior slope angle (delta) of the tibial components were well maintained both during the immediate postoperative period and at the final follow-up. There was no significant difference in the tibiofemoral angle and alpha, beta, gamma and delta angle (p>0.05) between the degenerative arthritis and rheumatoid arthritis groups. The alignment of the alternative substance was also relatively well maintained. Radiolucent lines were observed in 39 knees (18.7%), and in 42 zones out of 209 knees. The most common site of radiolucent lines was the medial side of the tibia in 21 knees. The overall incidence of radiolucent lines was 15% for the femur, 61% for the tibia and 24% for the patella. There was no statistically significant difference between the presence of radiolucent lines and the clinical results (p>0.05). There was 1 case of revision surgery due to loosening of implants at 8 years after surgery, but no early loosening was observed in the study subjects. Complications were found in 6 patients. Two patients with early postoperative infection were treated with revision surgery. Two patients with acute hematogenous infection 4 years after the initial operation were treated with revision surgery. Two patients with superficial infection were treated with antibiotics and regular dressing. CONCLUSION: The patients treated with the NexGen(R)-LPS TKRA had a decreased level of postoperative pain and an improved knee joint ROM. A lower rate of complications was also found with this type of implant.

A Comparison of the Short-term Results between the PCL Sacrificing Medial Pivot Knee and Nexgen(R) LPS Total Knee Arthroplasty

PURPOSE: We wanted to compare the clinical and radiological results after performing total knee arthroplasty (TKA) with the PCL sacrificing (PS) Medial Pivot Knee (MPK) and the Nexgen(R) LPS. MATERIALS AND METHODS: Seventy knees in 48 patients after TKA with the PS ADVANCE(R) MPK (group I) and 67 knees in 45 patients with the Nexgen(R) LPS (group II) were retrospectively evaluated. All the patients were followed up for more than 2 years. The evaluations included the preoperative and postoperative range of motion (ROM), the Knee Society (KS) scores, the tibiofemoral angle and the postoperative complications. RESULTS: For group I, the ROM increased from a mean flexion contracture of 6.3degrees and further flexion of 116.4degrees to 1.9degrees and 120.5degrees, respectively, and for group II, from 12.6degrees and 117.6degrees to 0.9degrees and 123.0degrees, respectively. For group I, the KS knee and function scores increased from 46 and 37 to 87 and 83, respectively, and for group II, from 50 and 48 to 87 and 83, respectively. For group I, the tibiofemoral angle changed from varus 4.0degrees to valgus 5.5degrees, respectively, and for group II, from varus 4.1degrees to valgus 5.3degrees, respectively. The complications were 2 knees (2.8%) with periprosthetic patellar fractures and 1 knee (1.4%) with a tibial component failure in group I, and 1 knee (1.5%) with early femoral component failure and 1 knee with arthrofibrosis (1.5%) in group II. CONCLUSION: The minimum 2-year follow-up results of PS MPK TKA were comparable to those of Nexgen(R) LPS TKA. However, we think that the MPK system has the advantage of more bony preservation at the femoral intercondylar notch area.