前十字靱帯再建術後の再損傷発生に関連する片脚スクワット中の運動学的因子の検討

Examination of Kinematic Factors during Single Leg Squatting Associated with the Occurrence of Re-injury after Anterior Cruciate Ligament Reconstruction

要旨

目的：本研究の目的は，前十字靱帯（ACL）再建術後に同側下肢のACL再損傷が発生する者としない者で術前の片脚スクワット動作中の膝関節可動域（ROM）とそれらの変動係数（CV）に違いがあるかどうかを明らかにすることである．

方法：対象は非接触型のACL損傷者38名である．全例がACL再建術の前日に片脚スクワット動作を行った．3次元動作解析装置を用いて片脚スクワット中の膝関節ROMとそれらのCVを算出した．ACL再建術後約30カ月後までに同側下肢のACL再損傷の発生について調査し，術後再損傷群と術後非損傷群で膝関節ROMとそれらのCVを比較した．

結果：術後再損傷群は9名，術後非損傷群は29名であった．術後再損傷群は術後非損傷群よりも膝関節内外旋ROMが大きく（再損傷群5.8±2.0°，非損傷群3.5±1.4°，p＝0.001），膝関節内外反CVが大きかった（再損傷群26.7±20.6％，非損傷群11.2±8.8％，p＝0.029）．

結論：ACL再建術前の片脚スクワット動作中の膝関節内外旋ROMと膝関節内外反CVはACL再損傷予防を検討するうえでの評価のポイントになると示唆された．

Abstract

Objective：This study aimed to determine the difference in knee joint range of motion (ROM) and coefficient of variation (CV) during preoperative single-leg squatting in patients who developed ipsilateral lower limb anterior cruciate ligament (ACL) re-injury months after ACL reconstruction and in those who did not have the injury.

Methods：Participants included 38 patients with non-contact ACL injuries. All patients underwent single-leg squatting the day before ACL reconstruction. Knee joint ROM and CV were assessed during single-leg squatting using a three-dimensional motion analysis system. We investigated the occurrence of ACL reinjury in the ipsilateral lower limb approximately 30 months after ACL reconstruction. Knee joint ROM and CV were then compared between the postoperative and non-injury groups.

Results：The postoperative injury and non-injury groups included 9 and 29 patients, respectively. The knee internal/external rotation ROM and CV of knee varus/valgus ROM were greater in the postoperative injury group than in the postoperative non-injury group.

Conclusion：During single-leg squatting before ACL reconstruction surgery, the knee internal/external rotation ROM and CV of knee varus/valgus ROM were suggested to be points of evaluation when considering ACL re-injury prevention.