The supraspinatus occupation ratios of both the ≥ 50% articular- and bursal-side partial-thickness rotator cuff tears were low and the infraspinatus occupation ratio of the ≥ 50% bursal-side partial-thickness rotator cuff tears was low.

PURPOSE: The purpose of this study was to analyze the relationship between the occupation ratio and partial-thickness rotator cuff tears. METHODS: The study included and retrospectively investigated 683 patients with partial-thickness rotator cuff tears between 2013 and 2017. Fifty patients with impingement syndrome were also enrolled as the control group for normal-population comparison. The participants were divided into five groups: Group A, control group; Group B, < 50% articular-side tears; Group C, ≥ 50% articular-side tears; Group D, < 50% bursal-side tears; and Group E, ≥ 50% bursal-side tears. Muscle volume was evaluated by measurement of each occupation ratio of the supraspinatus and infraspinatus tendons on the most lateral view of the T1-weighted oblique-sagittal images in which the scapular spine remained in contact with the scapular body. RESULTS: Fifty patients were enrolled in Group A. A total of 683 patients with Partial thickness rotator cuff tear were divided and classified into the following groups: 272 into Group B, 153 into Group C, 161 into Group D, and 97 into Group E. The supraspinatus occupation ratios of all partial-thickness rotator cuff tear groups were significantly lower than those of the control group. Furthermore, the supraspinatus occupation ratios of Groups C and E (≥ 50% partial-thickness rotator cuff tears) were significantly lower than those of Groups B and D (< 50% partial-thickness rotator cuff tears). However, the infraspinatus occupation ratio of only Group E was significantly lower than that of the other groups. CONCLUSION: The supraspinatus occupation ratios of both the ≥ 50% articular- and bursal-side partial-thickness rotator cuff tears were lower than those of the other partial-thickness rotator cuff tears. Conversely, the infraspinatus occupation ratio of only the ≥ 50% bursal-side partial-thickness rotator cuff tears was low. LEVEL OF EVIDENCE: IV.

Influence of anterolateral ligament injuries on stability and second-look arthroscopic findings after allograft transtibial anterior cruciate ligament reconstruction.

BACKGROUND: The purpose of this study was to evaluate the influence of anterolateral ligament (ALL) injuries on stability and second-look arthroscopic findings after anterior cruciate ligament (ACL) reconstruction. METHODS: One-hundred and nineteen consecutive patients underwent a second-look arthroscopic surgery after ACL reconstruction and magnetic resonance imaging (MRI) examination of the ALL. The patients were divided into an ALL intact group (n = 39) and ALL injured group (n = 80). The ALL injuries were divided according to the three anatomical parts of the ALL (femoral, meniscal, and tibial) using MRI evaluation. Stability and clinical results were evaluated using the Lachman test, pivot-shift test, KT-2000 arthrometer, and Lysholm score. On second-look arthroscopy, graft tension and synovial coverage were evaluated. RESULTS: The clinical evaluation revealed no significant differences in ALL injury. Although the synovial coverages showed no significant difference (P = 0.113), the second-look arthroscopic findings indicated that tension was statistically significantly dependent on the ALL injury (P < 0.001). In addition, according to the location of the ALL injury, femoral, tibial, and combined ALL injuries showed significant differences in graft tension as compared with the ALL intact group; only the meniscal injuries had no effect on graft tension. CONCLUSION: Combined ACL and ALL injuries showed poor graft tension in the second-look arthroscopic findings after allograft transtibial ACL reconstruction, even though no significant differences in clinical outcomes and stability were observed.