Background:The relationship between abnormalities of the ulnar collateral ligament (UCL) on magnetic resonance imaging (MRI) and elbow symptoms in baseball players remains unclear.Purpose/Hypothesis:This study aimed to compare findings of the UCL on microscopic MRI between asymptomatic and symptomatic elbows in baseball players. We hypothesized that the MRI grade of UCL injuries would exhibit no correlation with medial elbow symptoms in baseball players.Study Design:Cross-sectional study; Level of evidence, 3.Methods:The study participants were skeletally mature baseball players who underwent high-resolution microscopic MRI of the medial elbow including for medical checkups. Elbows with previous surgical treatment or traumatic UCL injuries were excluded. The patients were divided into symptomatic and asymptomatic groups. The UCL appearance on microscopic MRI was categorized into 4 grades and compared between the groups. Abnormal findings in the medial elbow including bony fragments at the medial epicondyle, osteophytes or bony fragments in the sublime tubercle, and bone marrow edema (BME) in the sublime tubercle were also evaluated.Results:A total of 426 baseball players (426 elbows) with a mean age of 20 years (range, 14-41 years) were included. The asymptomatic and symptomatic groups included 158 and 268 elbows, respectively. In the asymptomatic group, based on MRI grading of the UCL, 46 (29%) elbows were rated as grade I, 64 (41%) as grade II, 40 (25%) as grade III, and 8 (5%) as grade IV. In the symptomatic group, 75 (28%) elbows were rated as grade I, 118 (44%) as grade II, 61 (23%) as grade III, and 14 (5%) as grade IV. There was no significant difference in the MRI grades between the groups ( P = .9). BME in the sublime tubercle was more frequently seen in the symptomatic group than in the asymptomatic group ( P < .001).Conclusion:There was no difference in MRI grades of the UCL between symptomatic and asymptomatic elbows in baseball players; approximately 30% of elbows demonstrated high-grade UCL injuries in both groups. BME in the sublime tubercle was more frequently seen in symptomatic elbows than in asymptomatic elbows. BME in the sublime tubercle was a better indicator of symptoms than was MRI grading of the UCL.

中文翻译：

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显微磁共振成像比较棒球运动员无症状和有症状尺侧副韧带损伤


背景：磁共振成像 (MRI) 上的尺侧副韧带 (UCL) 异常与棒球运动员肘部症状之间的关系仍不清楚。目的/假设：本研究旨在比较无症状和有症状的尺侧副韧带 (UCL) 在显微 MRI 上的发现棒球运动员的肘部。我们假设 UCL 损伤的 MRI 分级与棒球运动员的肘内侧症状没有相关性。 研究设计：横断面研究；证据级别，3。方法：研究参与者是骨骼成熟的棒球运动员，他们接受了肘部内侧高分辨率显微 MRI 检查，包括进行体检。先前接受过手术治疗或外伤性 UCL 损伤的肘部被排除在外。将患者分为有症状组和无症状组。显微MRI上的UCL表现被分为4级并进行组间比较。还评估了肘内侧的异常发现，包括内上髁处的骨碎片、崇高结节中的骨赘或骨碎片以及崇高结节中的骨髓水肿（BME）。 结果：总共 426 名棒球运动员（426 个肘部）平均年龄为 20 岁（范围为 14-41 岁）。无症状组和有症状组分别包括 158 个和 268 个肘部。在无症状组中，根据 UCL 的 MRI 分级，46 个（29%）肘部被评为 I 级，64 个（41%）肘部为 II 级，40 个（25%）肘部为 III 级，8 个（5%）肘部为 III 级。四级。在症状组中，75 个（28%）肘部被评为 I 级，118 个（44%）肘部被评为 II 级，61 个（23%）肘部被评为 III 级，14 个（5%）肘部被评为 IV 级。各组间 MRI 分级无显着差异 ( P = .9)。 有症状组的大结节 BME 比无症状组更常见（P < .001）。结论：棒球运动员有症状和无症状肘部的 UCL MRI 分级没有差异；两组中大约 30% 的肘部均出现严重 UCL 损伤。与无症状的肘部相比，有症状的肘部更常见于崇高结节的 BME。与 UCL 的 MRI 分级相比，严重结节的 BME 是更好的症状指标。