Rhee Yong Girl, Cho Nam Su, Song Jong Hoon, Park Jung Gwan, Kim Tae Yong
Shoulder & Elbow Clinic, Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
Shoulder & Elbow Clinic, Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
J Shoulder Elbow Surg. 2017 Sep;26(9):1520-1526. doi: 10.1016/j.jse.2017.03.017. Epub 2017 May 5.
If the balance of the rotator cuff force couple is disrupted, pseudoparalysis may occur, but the exact mechanism remains unknown. This study investigated the effect of rotator cuff force couple disruption on active range of motion in massive rotator cuff tear (mRCT) by rotator cuff muscle volume analysis.
The study included 53 patients with irreparable mRCT: 22 in the nonpseudoparalysis group and 31 in the pseudoparalysis group. The volumes of the subscapularis (SBS), infraspinatus (ISP), and teres minor (TM) muscles were measured using magnetic resonance imaging (MRI), and the ratios of each muscle volume to the anatomic external rotator (aER) volume were calculated. A control group of 25 individuals with normal rotator cuffs was included.
Anterior-to-posterior cuff muscle volume ratio (SBS/ISP + TM) was imbalanced in both mRCT groups (1.383 nonpseudoparalysis and 1.302 pseudoparalysis). Between the 2 groups, the ISP/aER ratio (0.277 vs. 0.249) and the inferior SBS/aER ratio (0.426 vs. 0.390) were significantly decreased in the pseudoparalysis group (P= .022 and P= .040, respectively). However, neither the TM/aER ratio (0.357 vs. 0.376) nor the superior SBS/aER ratio (0.452 vs. 0.424) showed a significant difference between the two groups (P= .749 and P= .068, respectively). If the inferior SBS was torn, a high frequency of pseudoparalysis was noted (81.0%, P= .010).
The disruption of transverse force couple was noted in both irreparable mRCT groups, although no significant difference was found between the nonpseudoparalysis and pseudoparalysis groups. ISP and inferior SBS muscle volumes showed a significant decrease in pseudoparalysis group and, therefore, were considered to greatly influence the loss of active motion in mRCT. The TM did not exert significant effect on the incidence of pseudoparalysis.
如果肩袖力偶平衡被破坏，可能会发生假性麻痹，但其确切机制仍不清楚。本研究通过肩袖肌肉体积分析，探讨肩袖力偶破坏对巨大肩袖撕裂（mRCT）患者主动活动范围的影响。
本研究纳入53例不可修复性mRCT患者，其中非假性麻痹组22例，假性麻痹组31例。使用磁共振成像（MRI）测量肩胛下肌（SBS）、冈下肌（ISP）和小圆肌（TM）的体积，并计算每块肌肉体积与解剖学外旋肌（aER）体积的比值。纳入25名肩袖正常的个体作为对照组。
两个mRCT组的前后肩袖肌肉体积比（SBS/ISP + TM）均失衡（非假性麻痹组为1.383，假性麻痹组为1.302）。两组之间，假性麻痹组的ISP/aER比值（0.277对0.249）和肩胛下肌下部/aER比值（0.426对0.390）显著降低（P分别为0.022和0.040）。然而，两组之间的TM/aER比值（0.357对0.376）和肩胛下肌上部/aER比值（0.452对0.424）均无显著差异（P分别为0.749和0.068）。如果肩胛下肌下部撕裂，假性麻痹的发生率较高（81.0%，P = 0.010）。
在两个不可修复性mRCT组中均发现横向力偶破坏，尽管非假性麻痹组和假性麻痹组之间未发现显著差异。假性麻痹组的ISP和肩胛下肌下部肌肉体积显著降低，因此被认为对mRCT患者主动活动丧失有很大影响。TM对假性麻痹的发生率没有显著影响。
