Pennock Andrew T, Pytiak Andrew, Stearns Phillip, Roocroft Joanna H, Dwek Jerry, Kruk Peter, Bastrom Tracey P
Orthopedics & Scoliosis Division (A.T.P., A.P., P.S., J.H.R., and T.P.B) and Department of Radiology (J.D.), Rady Children's Hospital, San Diego, California Department of Orthopedic Surgery, University of California, San Diego, San Diego, California
Orthopedics & Scoliosis Division (A.T.P., A.P., P.S., J.H.R., and T.P.B) and Department of Radiology (J.D.), Rady Children's Hospital, San Diego, California.
J Bone Joint Surg Am. 2016 May 4;98(9):761-7. doi: 10.2106/JBJS.15.01017.
Youth baseball has been associated with elbow pain and elbow abnormalities, leading to the implementation of throwing and pitching guidelines. The purpose of the current study was to examine elbow abnormalities on magnetic resonance imaging (MRI) in asymptomatic Little League baseball players and to correlate these findings with the players' throwing history and physical examinations.
A prospective study of Little League players who were 10 to 13 years of age was performed. Players were recruited prior to the start of the season and underwent bilateral elbow MRI. All players underwent a physical examination and responded to a questionnaire addressing their playing history and any arm pain. The MRIs were read by 2 radiologists. Responses on the questionnaire and physical examination findings were compared between subjects with and without positive MRI findings utilizing chi-square and analysis of variance techniques.
Twenty-six players were enrolled. The majority (77%) were right-handed and 14 (54%) were a pitcher and/or catcher. Nine players (35%) had 12 positive MRI findings: 7 findings of edema or signal change of the medial epicondyle apophysis, 2 findings of fragmentation of the medial epicondyle, and 3 findings of edema or signal change of the sublime tubercle. The prevalence of positive MRI findings and a history of arm pain were not greater in pitchers and catchers compared with other players. Players with a positive MRI finding demonstrated greater reduction in shoulder internal rotation (12°) compared with the nondominant arm (3°) (p = 0.04). The two factors associated with a positive MRI finding were year-round play (47% of year-round players compared with 11% of non-year-round players; p < 0.01) and working with a private coach (71% compared with 21%; p = 0.02). Additionally, a history of pain was associated with year-round play and a private coach (p < 0.05).
MRI abnormalities involving the medial aspect of the elbow are common in year-round Little League baseball players, especially those with internal rotation deficits and private coaches. Although Little League guidelines potentially lessen abnormalities seen in pitchers, further refinement of these guidelines addressing year-round play, pain, and private coaching should be considered.
Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
青少年棒球运动与肘部疼痛和肘部异常有关，因此实施了投球和投球指导方针。本研究的目的是通过磁共振成像（MRI）检查无症状的小联盟棒球运动员的肘部异常情况，并将这些结果与运动员的投球历史和体格检查结果相关联。
对10至13岁的小联盟球员进行了一项前瞻性研究。在赛季开始前招募球员，并对其双侧肘部进行MRI检查。所有球员都接受了体格检查，并回答了一份关于他们比赛历史和任何手臂疼痛的问卷。MRI由两名放射科医生解读。利用卡方检验和方差分析技术，比较了MRI检查结果为阳性和阴性的受试者在问卷回答和体格检查结果方面的差异。
共招募了26名球员。大多数（77%）是右撇子，14名（54%）是投手和/或捕手。9名球员（35%）有12项MRI阳性结果：7项为内上髁骨骺水肿或信号改变，2项为内上髁碎裂，3项为小结节水肿或信号改变。与其他球员相比，投手和捕手中MRI阳性结果和手臂疼痛病史的发生率并不更高。MRI检查结果为阳性的球员与非优势手臂相比，肩部内旋减少幅度更大（12°对3°）（p = 0.04）。与MRI阳性结果相关的两个因素是全年参赛（全年参赛球员的47%，而非全年参赛球员的11%；p < 0.01）和与私人教练合作（71%对21%；p = 0.02）。此外，疼痛病史与全年参赛和私人教练有关（p < 0.05）。
在全年参加小联盟棒球运动的球员中，涉及肘部内侧的MRI异常情况很常见，尤其是那些有内旋缺陷和私人教练的球员。尽管小联盟指导方针可能会减少投手中出现的异常情况，但应考虑进一步完善这些指导方针以解决全年参赛、疼痛和私人教练指导等问题。
预后水平III。有关证据水平的完整描述，请参阅作者须知。
