Acute Elbow and Forearm Pain muscular avulsions of the common extensor origin and can depict lateral elbow compartmental pathologic laxity as evidence by widening of the articular joint space under dynamic stress maneuvers. Unfortunately, accurate identification of injuries to the lateral collateral ligament was not reliable. The majority of literature using US for the diagnosis of tendinous injuries is found in the setting of chronic elbow pain, particularly in the athlete. US of the elbow has moderate agreement with MRI of the elbow for the diagnosis and grading of common extensor tendon tears, with the sensitivity, specificity, and accuracy reported at 64.52%, 85.19%, and 72.73%, respectively [42]. Sonoelastography has shown promise for the detection of medial epicondylalgia with a sensitivity, specificity, accuracy, and positive predictive value, and negative predictive value of 95.2%, 92%, 93.5%, 90.0%, and 95.8%, respectively [43]. Conventional US has a sensitivity and specificity of 81% and 91%, respectively, in the detection of full-thickness UCL tears [44]. The sensitivity and specificity of dynamic stress US for the detection of UCL injury are 96% and 81%, respectively [44]. In a review of the literature, Sutterer et al [45] found that stress US can aid in the diagnosis of medial UCL tears, with an injured elbow stress delta (change in ulnohumeral joint space with valgus stress) of 2.4 mm and a stress delta difference (side-side difference in stress delta) of 1 mm, compatible with abnormal ulnohumeral joint laxity as a result of medial UCL injury. Given the scarcity of literature with regards to lateral and medial supporting structures, more rigorous studies evaluating the usefulness of US in the acute setting are needed; however, given US accuracy in the evaluation of chronic injuries, it will likely provide clinical usefulness for assessment of acute injury.
Acute Elbow and Forearm Pain. Acute Elbow and Forearm Pain muscular avulsions of the common extensor origin and can depict lateral elbow compartmental pathologic laxity as evidence by widening of the articular joint space under dynamic stress maneuvers. Unfortunately, accurate identification of injuries to the lateral collateral ligament was not reliable. The majority of literature using US for the diagnosis of tendinous injuries is found in the setting of chronic elbow pain, particularly in the athlete. US of the elbow has moderate agreement with MRI of the elbow for the diagnosis and grading of common extensor tendon tears, with the sensitivity, specificity, and accuracy reported at 64.52%, 85.19%, and 72.73%, respectively [42]. Sonoelastography has shown promise for the detection of medial epicondylalgia with a sensitivity, specificity, accuracy, and positive predictive value, and negative predictive value of 95.2%, 92%, 93.5%, 90.0%, and 95.8%, respectively [43]. Conventional US has a sensitivity and specificity of 81% and 91%, respectively, in the detection of full-thickness UCL tears [44]. The sensitivity and specificity of dynamic stress US for the detection of UCL injury are 96% and 81%, respectively [44]. In a review of the literature, Sutterer et al [45] found that stress US can aid in the diagnosis of medial UCL tears, with an injured elbow stress delta (change in ulnohumeral joint space with valgus stress) of 2.4 mm and a stress delta difference (side-side difference in stress delta) of 1 mm, compatible with abnormal ulnohumeral joint laxity as a result of medial UCL injury. Given the scarcity of literature with regards to lateral and medial supporting structures, more rigorous studies evaluating the usefulness of US in the acute setting are needed; however, given US accuracy in the evaluation of chronic injuries, it will likely provide clinical usefulness for assessment of acute injury.