Hersche O, Gerber C
Department of Orthopaedics, University of Zurich, Switzerland.
J Shoulder Elbow Surg. 1998 Jul-Aug;7(4):393-6. doi: 10.1016/s1058-2746(98)90030-1.
Incomplete functional recovery after rotator cuff surgery can be caused by rerupture or incomplete restoration of the contractile properties of the muscle-tendon-bone unit. We measured the passive tension generated in the supraspinatus musculotendinous unit at the time of repair of the supraspinatus tendon performed for the treatment of long-standing rupture in four patients and compared our results with the values of an intact musculotendinous unit. In stepwise elongation from 10 to 20 mm, passive tension increased by a factor of 2.2 +/- 0.4 in the study group. In the control case passive tension increased by a factor of only 1.3. Mean tension in 60 degrees of abduction was 14.25 +/- 3.4 N in the four long-standing ruptures and 10 N in the control case. If the arm was brought to the side, tension rose to 25 N in the control case, whereas mean tension increased to 59.25 +/- 12.7 N in long-standing rupture of the supraspinatus muscle. Our findings demonstrate that passive tension in the supraspinatus is increased after long-standing rupture of its tendon. This result suggests that active force generation by this muscle will be compromised after surgery and that the high strain after repair may expose the musculotendinous unit to further damage.
肩袖手术术后功能恢复不完全可能是由于肌腱 - 骨单元的再断裂或收缩特性恢复不完全所致。我们测量了4例因长期肩袖破裂接受肩袖肌腱修复手术患者在修复时冈上肌肌腱单元产生的被动张力，并将结果与完整肌腱单元的值进行比较。在从10毫米到20毫米的逐步拉伸过程中，研究组的被动张力增加了2.2±0.4倍。在对照病例中，被动张力仅增加了1.3倍。4例长期破裂患者在60度外展时的平均张力为14.25±3.4牛，对照病例为10牛。如果将手臂放于身体一侧，对照病例中的张力升至25牛，而在冈上肌长期破裂时，平均张力增至59.25±12.7牛。我们的研究结果表明，冈上肌腱长期破裂后，其被动张力增加。这一结果表明，该肌肉术后产生主动力的能力将受到损害，修复后的高应变可能使肌腱单元受到进一步损伤。
