NexGen LPS-Flex®を使用した人工膝関節置換術の短期成績

Short-Term Results of Total Knee Arthroplasty with the NexGen LPS-Flex Prosthesis

　抄録：NexGen LPS-Flex^®人工膝関節を用いたTKA，80例94膝の短期成績を検討した．この機種は，深屈曲が可能となるようにデザインされている．症例は，男性12例13膝，女性68例81膝で手術時平均年齢は71歳（60～85歳）であった．疾患は全例OAであった．平均追跡期間は18.7カ月（12～30カ月）であった．術前後の膝可動域，JOAスコア，および立位X線像上のFTA（膝外側角），クリアゾーンなどを評価した．平均膝屈曲角度は術前118.9±23.3°から術後126.3±21.1°と著明に改善を認めた．JOAスコアも術前56.9±10.8点から術後82.7±7.3点に著明に改善を認めた．FTAは術前183.6±8.9°から術後170.5±4.6°になった．X線像にて7膝にけい骨コンポーネント周囲にクリアゾーンを認めた．短期成績では良好な結果が得られた．

　We investigated the short-term outcome of 94 primary total knee arthroplasties (80 patients) performed with the NexGen LPS-Fle^® xprosthesis, which has been designed to enable the knee to flex deeply. There were 12 men (13 knees) and 68 women (81 knees), and their mean age of at the time of the operation was 71 years (60 to 85). All patients has been diagnosed with osteoarthritis. The mean follow-up time was 18.7 months (12 to 30). The clinical outcome was evaluated based on the pre-and post-operative range of motion (ROM), Japanese Orthopaedic Association (JOA) knee rating score, and radiographic findings (femoro-tibial angle ［FTA］, radiolucent line, etc.). The mean degrees of knee flexion had improved significantly, from 118.9±23.3° preoperatively to 126.3±21.1° postoperatively. The JOA knee rating score also improved significantly, from 56.9±10.8 to 82.7±7.3, and the FTA had changed from 183.6±8.9° to 170.5±4.6°. A radiolucent line was present on 7 knees around the tibial component. Thus, the short-term outcome of total knee arthroplasty with the NexGen LPS-Flex^® prosthesis was satisfactory, but careful long-term follow of these cases is necessary.