The Mid-Term Results of High-Flex Total Knee Arthroplasty: Minimum 5-Year Follow-Up Results / 대한정형외과학회잡지

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the mid-term results of high-flexion total knee arthroplasty. MATERIALS AND METHODS: We retrospectively reviewed 77 patients who underwent 119 total knee arthroplastys using high-flexion implants (LPS-flex(R) , Zimmer, Warsaw, IN, USA) from November 2004 to June 2006. The mean age was 67.3 years (range, 54-83 years), and the average follow-up duration was 71.1 months. We assessed preoperative and last follow-up functional outcomes with ranges of motion (ROM) and the Hospital for Special Surgery (HSS) score and investigated their ability to squat, sit cross-legged knee, kneel, or stand up from the floor or a chair at the final follow-up. The Knee Society Radiographic evaluation and scoring system was used for radiologic evaluation. RESULTS: The mean ROM increased from 104.7degrees preoperatively to 129.8degrees postoperatively at the final follow-up. The average HSS score improved from 42.7 points preoperatively to 93.5 points postoperatively. At the final follow-up, 33 patients (42.8%) were able to squat; 75 patients (97.4%) were able to sit cross-legged; 27 patients (35.0%) were able to kneel; 45 patients (58.4%) were able to stand up from the floor and 73 patients (94.8%) were able to stand up from a chair. Six cases encountered stiff knees as a complications, and were treated with manipulation procedures. 1 mm radiolucent lines were detected in 5 cases, but none of them were progressive. CONCLUSION: We believe that the hyperflexion implant itself is not a cause of early loosening. Research on reasons regarding early loosening and long-term follow-ups will be needed.