The Role of Ultrasound in the Evaluation of Elbow Medial Ulnar Collateral Ligament Injuries in Throwing Athletes

Abstract

Purpose of Review Although ultrasound (US) imaging is commonly used to evaluate the elbow medial ulnar collateral ligament (mUCL) in throwing athletes, significant technical heterogeneity exists in the published literature and in practice. This has resulted in variable and often ambiguous US diagnostic criteria for mUCL injury. This review summarizes the literature on sonographic evaluation of the mUCL and outlines recommendations for consistent descriptive terminology, as well as future clinical and research applications. Recent Findings Both acute and chronic throwing loads in overhead athletes cause the mUCL to become thicker and more lax on stress testing, and these changes tend to revert after a period of prolonged rest. Stress US (SUS) can aid in the diagnosis of mUCL tears and may help identify athletes at risk of mUCL injury. Variability exists in terminology, elbow flexion angle, amount of stress applied, and technique of stress testing. Recent studies have suggested an injured elbow stress delta (SD—change in ulnohumeral joint (UHJ) space with valgus stress) of 2.4 mm and a stress delta difference (SDD—side-side difference in SD) of 1 mm each denote abnormal UHJ laxity due to mUCL injury. Summary US imaging is a powerful and widely accessible tool in the evaluation elbow mUCL injuries. Sonologists should consider how their US techniques compare with published methods and use caution when applying diagnostic criteria outside of those circumstances. Currently, an SD of 2.4 mm and an SDD of 1 mm provide the best diagnostic accuracy for mUCL tears requiring surgery. Finally, preliminary work suggests that shear wave elastography may be helpful in evaluating the biomechanical properties of the mUCL, but additional research is needed.

Distribution and Prevalence of Elbow Pain (EP) in Elite Swimmers in Tianjin, China—A Regional Epidemiological Study

“…Finally, ligament and tendon injuries could also be among the causes of EP [42][43][44][45]. In some clinical medical studies and anatomical literature, baseball players with elbow injures typically require surgical rehabilitation [44,46]. Therefore, for EP swimmers identified as experiencing critical pain in this study, we recommend further medical examinations to mitigate the risk of ligament and tendon injuries exacerbating their EP condition.…”

“…Therefore, we suggest that swimming teams and clubs at all levels should consider implementing "periodization theory" as the training management principle to address deficiencies, which can provide athletes with maximum rest during busy training schedules [41]. Finally, ligament and tendon injuries could also be among the causes of EP [42][43][44][45]. In some clinical medical studies and anatomical literature, baseball players with elbow injures typically require surgical rehabilitation [44,46].…”

Orthobiologic Treatment of Throwing Related Injuries in Sport: A Focused Review of the Published Literature

“…The utility of stress ultrasound imaging (SUS) has been shown to improve diagnostic accuracy of UCL injuries. Objectively, data has revealed that a side to side difference of more than 1 millimeter or a dominant stress versus nonstress difference of 2.4 millimeters indicate UCL tears requiring surgical intervention (25). Thus, one must consider that if PRP is used in a patient with a partial UCL tear but has not had a SUS completed to assess for UHJ laxity, healing and RTP success rates may be inaccurate.…”

Association Between Draft Order and Stress Sonography of the Ulnar Collateral Ligament of the Elbow in Professional Baseball Pitchers: An 18-Year Study

“…7,8,16,27 Dynamic stress ultrasound (SUS) is a reliable tool for evaluating the structure of the UCL and determining injury. 6,10,11,13,15,28,31 The UCL of the dominant arm in pitchers is thicker and has increased laxity compared with the contralateral elbow on SUS. 2,10,19,29 Although SUS has been used to evaluate the risk of increased pitch count and pitch volume on the change in UCL morphology, to our knowledge, no study has investigated SUS findings of the UCL in professional baseball players with respect to their draft position in the MLB draft.…”