Kikukawa Kenshi, Ide Junji, Kikuchi Ken, Morita Makoto, Mizuta Hiroshi, Ogata Hiroomi
Department of Orthopaedic Surgery, Kumamoto Social Insurance General Hospital, Yatsushiro, Kumamoto, Japan.
Department of Advanced Joint Reconstructive Surgery, Kumamoto University Hospital, Kumamoto University, Kumamoto, Japan.
J Shoulder Elbow Surg. 2014 Dec;23(12):1800-1805. doi: 10.1016/j.jse.2014.03.014. Epub 2014 Jun 4.
Few reports have assessed the teres minor (TM) muscle in rotator cuff tears. This study aimed to quantitatively analyze the morphologic changes of the TM muscle in patients with or without rotator cuff tears by magnetic resonance imaging (MRI).
This retrospective study consisted of 279 subjects classified on the basis of interpretations of conventional MRI observations into 6 groups: no cuff tear; partial-thickness supraspinatus (SSP) tear; full-thickness SSP tear; SSP and subscapularis tears; SSP and infraspinatus (ISP) tears; and SSP, ISP, and subscapularis tears. With use of ImageJ software (National Institutes of Health, Bethesda, MD, USA) for oblique sagittal MRI, we measured the areas of ISP, TM, and anatomic external rotation (ISP + TM) muscles on the most lateral side in which the scapular spine was in contact with the scapular body. The occupational ratios of the TM muscle area to the anatomic external rotation muscle area were calculated. Ratios above the maximum of the 95% confidence intervals of the occupational ratio in the no-tear group were defined as hypertrophy of the TM muscle.
Occupational ratios of the TM muscle in the no-tear group followed a normal distribution, and ratios >0.288 were defined as hypertrophic. Hypertrophic changes of the TM muscle were confirmed in rotator cuff tears involving the ISP tendon. A negative correlation was found between the occupational ratios of TM and ISP (P < .001).
The TM muscle appeared hypertrophic in rotator cuff tears involving the ISP, and the progression of ISP muscle atrophy seemed to induce the development of this compensatory hypertrophy.
很少有报告评估肩袖撕裂患者的小圆肌（TM）。本研究旨在通过磁共振成像（MRI）定量分析有或无肩袖撕裂患者的TM形态变化。
这项回顾性研究纳入了279名受试者，根据传统MRI观察结果分为6组：无肩袖撕裂；冈上肌（SSP）部分厚度撕裂；SSP全层撕裂；SSP和肩胛下肌撕裂；SSP和冈下肌（ISP）撕裂；以及SSP、ISP和肩胛下肌撕裂。使用ImageJ软件（美国国立卫生研究院，马里兰州贝塞斯达）对斜矢状面MRI进行分析，我们在肩胛冈与肩胛体接触的最外侧测量了ISP、TM和解剖外旋（ISP + TM）肌肉的面积。计算TM肌肉面积与解剖外旋肌肉面积的占比。无撕裂组占比高于95%置信区间最大值的被定义为TM肌肉肥大。
无撕裂组TM肌肉的占比呈正态分布，占比>0.288被定义为肥大。在涉及ISP肌腱的肩袖撕裂中证实了TM肌肉的肥大变化。发现TM和ISP的占比之间存在负相关（P <.001）。
在涉及ISP的肩袖撕裂中，TM肌肉出现肥大，ISP肌肉萎缩的进展似乎诱导了这种代偿性肥大的发展。
