Background:

Partial-thickness rotator cuff tears are common shoulder injuries in baseball players. For some tears, the symptoms can be relieved through physical therapy or debridement without rotator cuff repair.

Purpose:

To assess whether partial-thickness rotator cuff tear by itself causes shoulder pain and muscle weakness in baseball players.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We studied 87 university baseball players (age, 19.5 ± 0.8 years; baseball career, 11.5 ± 1.6 years). All data were obtained during a full-participation annual medical check in 1 team. Rotator cuff tendons were examined ultrasonographically and allocated to 4 groups: (1) no tear, (2) supraspinatus tendon tear, (3) infraspinatus tendon tear, and (4) both supraspinatus and infraspinatus tendon tears. Current shoulder pain and shoulder muscle strength (dominant/nondominant) in abduction, external rotation, and internal rotation were compared by using chi-square and t tests. All players could play baseball with or without shoulder pain in this study.

Results:

Of the 87 players, 41 (47%) had articular-sided partial-thickness rotator cuff tears diagnosed on ultrasonography; the remaining 46 athletes were tear-free. Of the 41 affected patients, 19 had tears in the supraspinatus, 13 in the infraspinatus, and 9 in both the supraspinatus and infraspinatus tendons. Tear depth (mean ± SD) was 4.6 ± 2.3 mm in the supraspinatus and 6.2 ± 3.6 mm in the infraspinatus. Neither the rate of shoulder pain nor muscle strength differed significantly among the 4 groups (P = .96 and P = .15-.70, respectively).

Conclusion:

Articular-sided partial-thickness rotator cuff tear—by itself—did not cause shoulder pain and muscle weakness in university baseball players. Most so-called articular-sided partial-thickness rotator cuff tears may not be pathologic tendon tears.

中文翻译：

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厚度不全的肩袖撕裂本身不会引起棒球运动员的肩痛或肌肉无力。

背景：

在棒球运动员中，偏厚的肩袖撕裂是常见的肩部受伤。对于某些眼泪，可通过物理疗法或清创术缓解症状，而无需修复肩袖。

目的：

评估部分厚度的肩袖撕裂本身是否会引起棒球运动员的肩部疼痛和肌肉无力。

学习规划：

横断面研究；证据水平3。

方法：

我们研究了87位大学棒球运动员（年龄19.5±0.8岁；棒球职业11.5±1.6岁）。所有数据都是在一个团队的全员年度医学检查中获得的。超声检查肩袖肌腱并分为4组：（1）无撕裂，（2）棘上肌腱撕裂，（3）鼻下肌腱撕裂，和（4）棘上肌和鼻下肌腱撕裂。使用卡方检验和t检验比较了当前的肩关节疼痛，外展，外旋和内旋中的肩部疼痛和肩部肌肉力量（显性/中枢性）。在这项研究中，所有球员都可以打棒球，无论有无肩痛。

结果：

在87名运动员中，有41名（47％）在超声检查中被诊断出关节侧偏厚的肩袖撕裂。剩下的46名运动员是无泪的。在41名受影响的患者中，有19只在上睑上裂，13只在鼻下韧带，以及9只在上睑和下肌腱都有眼泪。上棘上的撕裂深度（平均值±标准偏差）为4.6±2.3 mm，而在椎弓下的撕裂深度为6.2±3.6 mm。在这四组中，肩痛的发生率和肌肉力量均无显着差异（分别为P = 0.96和P = 0.15-0.70）。

结论：

关节侧偏厚肩袖撕裂本身并不会引起大学棒球运动员的肩部疼痛和肌肉无力。多数所谓的关节侧偏厚肩袖撕裂可能不是病理性肌腱撕裂。