J Korean Orthop Assoc.  2012 Aug;47(4):271-276. 10.4055/jkoa.2012.47.4.271.

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

• Kim KM
• Chun CH
• Kang HJ
• No SH

• KMID: 2185374
• DOI: http://doi.org/10.4055/jkoa.2012.47.4.271

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.

Keyword

total knee arthroplasty; high-flexion implants

MeSH Terms

Floors and Floorcoverings
Follow-Up Studies
Humans
Knee
Retrospective Studies

Figure

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  Figure 1 A 68-year-old female with left knee osteoarthritis underwent total knee arthroplasty using high flexion prosthesis. (A) She could sit cross-legged, kneel and squat comfortably at 68 months follow-up. (B, C) Anteroposterior, lateral, and fluoroscopic views showed no loosening or wear. (D) Lateral full flexion view was obtained to measure further flexion angle.

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