Abstract
[Purpose] Recently, great progress has been made toward the improvement of the diagnosis for a partial tear of the rotator cuff (R. C. ). However, in spite of these fine preoperative evaluations, it has been very difficult to identify the location of a partial tear of the R. C. during surgery. The purpose of this study was to investigate the degree of relaxation of a R. C. With a partial tear and was to identify the location of the tear intraoperatively.
[Materials and Methods] 15 shoulders of 12 males and 3 females were diagnosed with partial R. C. tears by arthrogram and intraoperative findings. Their mean age was 59 years old (range 32 to 80 yrs. ). All the cases had an incomplete rupture in the tendon of the supraspinatus,14 cases showed an articular side tear and 1 case showed a bursal side tear. The traction test of the R. C. was done in the following manner: A load of 20 N was applied to the three parts of the R. C.2cm proximally from the facet in the direction of each tendon through the suture traction. The displacement of the suture point was measured.
[Results] The partial ruptured tendon had a 9.4mm length displacement by the load. Against these results, the intact tendon indicated a 4.7mm length displacement in the anterior cuff and 4.9mm length displacement in the posterior cuff.
[Discussion] In a partial tear of the R. C. the tendon was seen to be relaxed even if the tendon appeared to have continuity. This means a partial tear of the R. C. would be similar to a full thickness tear of the R. C. in terms of shoulder function. Consequently, the intraoperative traction test of the tendon is a useful method for the diagnosis and a functional evaluation for a partial tear of the R. C..
