Shoulder and Elbow Service, Department of Orthopaedic Surgery, Washington University School of Medicine, 1 Barnes-Jewish Hospital Plaza, 11300 West Pavilion, Campus Box 8233, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
J Bone Joint Surg Am. 2010 Apr;92(4):829-39. doi: 10.2106/JBJS.H.01746.
Fatty degeneration of the rotator cuff muscles may have detrimental effects on both anatomical and functional outcomes following shoulder surgery. The purpose of this study was to investigate the relationship between tear geometry and muscle fatty degeneration in shoulders with a deficient rotator cuff.
Ultrasonograms of both shoulders of 262 patients were reviewed to assess the type of rotator cuff tear and fatty degeneration in the supraspinatus and infraspinatus muscles. The 251 shoulders with a full-thickness tear underwent further evaluation for tear size and location. The relationship of tear size and location to fatty degeneration of the supraspinatus and infraspinatus muscles was investigated with use of statistical comparisons and regression models.
Fatty degeneration was found almost exclusively in shoulders with a full-thickness rotator cuff tear. Of the 251 shoulders with a full-thickness tear, eighty-seven (34.7%) had fatty degeneration in either the supraspinatus or infraspinatus, or both. Eighty-two (32.7%) of the 251 full-thickness tears had a distance of 0 mm between the biceps tendon and anterior margin of the tear. Ninety percent of the full-thickness tears with fatty degeneration in both muscles had a distance of 0 mm posterior from the biceps, whereas only 9% of those without fatty degeneration had a distance of 0 mm. Tears with fatty degeneration had significantly greater width and length than those without fatty degeneration (p < 0.0001). Tears with fatty degeneration had a significantly shorter distance posterior from the biceps than those without fatty degeneration (p < 0.0001). The distance posterior from the biceps was found to be the most important predictor for supraspinatus fatty degeneration, whereas tear width and length were found to be the most important predictors for infraspinatus fatty degeneration.
Fatty degeneration of the rotator cuff muscles is closely associated with tear size and location. The finding of this study suggests that the integrity of the anterior supraspinatus tendon is important to the development of fatty degeneration. Patients with full-thickness tears that extend through this area may benefit from earlier surgical intervention if fatty degeneration has not already occurred. Additionally, the findings suggest the importance of secure fixation and healing of the anterior aspect of the supraspinatus with surgical repair.
肩袖肌肉的脂肪变性可能对肩部手术后的解剖和功能结果产生不利影响。本研究的目的是探讨在肩袖缺损的情况下，肩袖撕裂的几何形状与肌肉脂肪变性之间的关系。
对 262 例患者的双侧肩关节进行超声检查，以评估肩袖撕裂的类型和冈上肌及冈下肌的脂肪变性情况。对 251 例全层撕裂的肩关节进行进一步评估，以评估撕裂的大小和位置。使用统计学比较和回归模型研究撕裂的大小和位置与冈上肌和冈下肌脂肪变性之间的关系。
脂肪变性几乎仅见于全层肩袖撕裂的肩关节。在 251 例全层撕裂中，87 例（34.7%）的冈上肌或冈下肌或两者均有脂肪变性。在 251 例全层撕裂中，82 例（32.7%）的肱二头肌肌腱与撕裂前缘之间的距离为 0mm。90%的双侧肌肉脂肪变性的全层撕裂的肱二头肌后缘距离为 0mm，而没有脂肪变性的全层撕裂中只有 9%的距离为 0mm。有脂肪变性的撕裂的宽度和长度明显大于没有脂肪变性的撕裂（p < 0.0001）。有脂肪变性的撕裂的肱二头肌后缘距离明显小于没有脂肪变性的撕裂（p < 0.0001）。研究发现，肱二头肌后缘距离是冈上肌脂肪变性最重要的预测因素，而撕裂的宽度和长度是冈下肌脂肪变性最重要的预测因素。
肩袖肌肉的脂肪变性与撕裂的大小和位置密切相关。本研究的结果表明，前冈上肌腱的完整性对脂肪变性的发展很重要。对于已经延伸到该区域的全层撕裂患者，如果尚未发生脂肪变性，可能需要更早的手术干预。此外，研究结果还表明，在进行手术修复时，确保前肩袖的前部固定和愈合非常重要。
