単椎間腰椎椎体間固定術の獲得局所前弯角―PLIFとTLIFとの比較

Acquisition of Postoperative Local Lordosis by Single-level Posterior Lumbar Interbody Fusion. A Comparison Between Posterior Lumbar Interbody Fusion (PLIF) and Transforaminal Lumbar Interbody Fusion (TLIF)

　背景：腰椎椎体間固定術症例の獲得局所前弯角を後方進入腰椎椎体間固定術(PLIF)，経椎間孔腰椎椎体間固定術(TLIF)間で比較した．

　対象と方法：対象はL5/Sに同一の馬蹄型ケージを用いて椎体間固定術を施行した51例とした．PLIF群(24例)，TLIF群(27例)の2群に分け，術前・術直後で比較した．

　結果：PLIF群は前弯角が術前5.6°から術直後12.9°へ増大し，TLIF群では術前9.8°から術直後11.5°に増大しており，PLIF群で有意に獲得前弯角が大きかった．

　まとめ：本研究から，L5/Sでの前弯獲得が必要な症例では，PLIFを選択すべきである．

　Purpose：The purpose of this study was to compare postoperative local lordosis after PLIF and TLIF.

　Materials and Methods：Fifty-one patients who had undergone single-level lumbar interbody fusion at L5/S between 2006 and 2010 were the subjects of this study.　The patients were divided into a PLIF group (17 males and 7 females) and a TLIF group (11 males and 16 females).　Their lumbar lordosis angle and cage height were measured and compared.

　Results：The lumbar lordotic angle was 5.6 degrees preoperatively and 12.9 degrees postoperatively in the PLIF group, and 9.8 degrees preoperatively and 11.5 degrees postoperatively in the TLIF group.　The increase in the lumbar lordotic angle in the PLIF group was significantly greater than in the TLIF group (p＜0.001).　Cage height was 9.2 mm in the PLIF group and 9.1 mm in the TLIF group, and the difference was not significant.

　Conclusion：PLIF tended to result in a greater increase in lordosis at L5/S than TLIF did, and PLIF is therefore recommended for patients who have a smaller lordotic angle at the L5/S level.