抄録
We divided the rotator cuff tear part according to the articular surface of the greater tubercle of the humerus and conducted an investigation into the influence that each gave to each rotator muscle power.
From October 2004 to April 2007, we evaluated 80 patients with rotator cuff tear. We defined the location of cuff tear the facet as zone one ; superior facet, as zone2 ; anterior part of middle facet, as zone3 ; posterior part of the middle facet, and as over zones 1,2,3. We measured both sides of the muscle strength of abduction, external rotation, internal rotation, internal rotation using Microfet. The muscle strength of the unaffected side became significantly big in order of abductor power < external rotation power < adductor power (P <0.001). Each muscle strength test showed that JOBE <40°, ISP <ER2 (P <0.01), BPT <SSC (NS). Regardless of tear size, on the rotator cuff tear side, muscle strength showed that abductor power < external rotation power < adductor power (P <0.001), but did not show significant differences between each muscle strength tests. The muscle strength rate of the affected side for the unaffected side according to a part on greater tubercle of humerus of a rotator cuff tear, was Zone 1, 83%, 83%, 90%, Zone 1,2 , 72.5%, 76%, 87%, Zone 1,2,3, 79%, 75%, 88%, 49% that were bigger than Zone 1,2,3, 39%, 91% in order of abduction, external otation, adduction. In the cases of cuff tear on the superior facet only, not only exterenal rotation power but also external and internal rotation power decreased.
