Magnetic resonance imaging of the elbow. Part I: Normal anatomy,imaging technique,and osseous abnormalities

Part I of this comprehensive review on magnetic resonance imaging of the elbow discusses normal elbow anatomy and the technical factors involved in obtaining high-quality magnetic resonance images of the elbow. Part I also discusses the role of magnetic resonance imaging in evaluating patients with osseous abnormalities of the elbow. With proper patient positioning and imaging technique, magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the osseous structures of the elbow. Magnetic resonance imaging can detect early osteochondritis dissecans of the capitellum and can be used to evaluate the size, location, stability, and viability of the osteochondritis dissecans fragment. Magnetic resonance imaging can detect early stress injury to the proximal ulna in athletes. Magnetic resonance imaging can detect radiographically occult fractures of the elbow in both children and adults. Magnetic resonance imaging is also useful in children to further evaluate elbow fractures which are detected on plain-film radiographs.Part II of this review can be found at:     

Magnetic resonance imaging of the shoulder in asymptomatic professional baseball pitchers.

The purpose of this study was to evaluate the magnetic resonance imaging findings in both shoulders of asymptomatic professional baseball pitchers. Fourteen pitchers who were without significant prior injury underwent a blinded clinical assessment and magnetic resonance imaging of both shoulders. All images were interpreted by two experienced musculoskeletal radiologists. The appearance of the rotator cuff tendons was graded, with additional evaluation of the biceps, labrum, and osseous structures. Ten athletes were found to have stable shoulders and painless full range of motion. Clinically, four athletes had at least a 40 degrees loss in internal rotation as compared with the nonthrowing arm. There were no significant differences in magnetic resonance imaging findings of the supraspinatus and infraspinatus tendons between the throwing and nonthrowing shoulders. The labrum was abnormal in 79% of the 28 shoulders. Enthesopathic changes of the posterior glenoid labrum were identified in the four pitchers who had loss of internal rotation. We conclude that unenhanced magnetic resonance imaging of the shoulder in asymptomatic high performance throwing athletes reveals abnormalities that may encompass a spectrum of "nonclinical" findings. These data can be useful in separating symptomatic pathologic findings from these variants. Enthesopathic changes of the posterior glenoid labrum in the throwing arm may represent an early Bennett-type lesion. The cause may be excessive traction on the posterior capsule during the pitching motion, with subclinical injury to this area.     

Avulsion fracture of the ulnar sublime tubercle in overhead throwing athletes

BACKGROUND: Injuries to the ulnar collateral ligament are relatively common in throwing athletes and result from either acute traumatic or repeated valgus stress to the elbow. Avulsion fracture of the sublime tubercle of the ulna is a rarely reported site of ulnar collateral ligament injury. PURPOSE: We retrospectively reviewed our cases of ulnar collateral ligament injuries to study avulsion fractures of the sublime tubercle of the ulna. STUDY DESIGN: Case series. METHODS: Data, including radiographs and magnetic resonance imaging scans, were obtained by review of hospital and office records and by follow-up examination. Of 33 consecutive patients treated for ulnar collateral ligament injuries, 8 had avulsion fractures of the sublime tubercle of the ulna. All eight were male baseball players with dominant arm involvement, an average age of 16.9 years, and an average follow-up of 23.6 months. RESULTS: Six of eight patients had failure of nonoperative treatment and required surgical repair. Two of the six underwent ulnar collateral ligament reconstruction and four had direct repair of the sublime tubercle avulsion with bioabsorbable suture anchors. At last follow-up, all eight had returned to their preinjury level of activity. No patient had residual medial elbow pain or laxity. CONCLUSIONS: Diagnosis of sublime tubercle avulsion fracture is made with history, physical examination, and radiographic studies. Magnetic resonance imaging can help identify an avulsion fracture not visible radiographically and can help determine whether direct repair or reconstruction is needed.     

Magnetic resonance imaging of the elbow

With the current popularity of racket and throwing sports, the number of individuals seeking medical care for elbow pain and dysfunction has increased. Elbow dysfunction may be related to acute or chronic injury to the soft tissue or osseous components of the elbow. With magnetic resonance imaging (MRI), it is now possible to accurately determine the nature and extent of the pathological changes in ligaments, tendons, muscles, and osseous structures of the elbow joint. This information facilitates the choice of the appropriate therapeutic regimen.     

Diagnostic imaging of elbow injuries inthe throwing athlete

The elbow is a complex joint that connects the arm with the forearm. Injuries to the elbow in the throwing athlete aregenerally caused by acute trauma or repetitive stress. Diagnostic imaging of the elbow ranges from plain radiographs to magnetic resonance/arthrography. Because of the complex nature of the joint, a good history of the patient and physical exam should be obtained in an attempt to tailor the imaging workup for each individual. Most acute traumatic injuries can be diagnosed with plain radiographs. Computed tomography and magnetic resonance imaging (± intra-articular contrast) are generally obtained to confirm suspected pathology from the patient's history and physical exam. This article will discuss several pathologic conditions and will attempt to show the findings seen on the appropriate imaging modality. Where it is possible, the mechanism of injury will be described and correlated with the imaging findings.     

Medial ulnar collateral ligament reconstruction of the elbow in throwing athletes

BACKGROUND: Medial ulnar collateral ligament insufficiency of the elbow can be a devastating injury in the throwing athlete. Reconstruction of the medial ulnar collateral ligament was initially described by Jobe and associates; good clinical results have been described after this procedure. The authors' experience with this technique raised several concerns, and thus the "docking" procedure was developed as an alternative method for medial ulnar collateral ligament reconstruction of the elbow. The early results of the docking technique were good. The authors wish to investigate the intermediate-term clinical results of this method in a large group of athletes. HYPOTHESIS: The docking technique can return overhead-throwing athletes to sport with minimal perioperative morbidity. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: During a 3-year period, 100 consecutive overhead-throwing athletes were treated with surgical reconstruction using the docking technique. The inclusion criteria were as follows: (1) a history of medial elbow pain that prevented throwing, (2) a preoperative standard noncontrast magnetic resonance image demonstrating medial ulnar collateral ligament injury, (3) clinically apparent medial ulnar collateral ligament insufficiency, and (4) an overhead-throwing athlete. At the time of surgery, all patients underwent routine arthroscopic assessment. The ulnar nerve was transposed in 22 cases. The mean follow-up was 36 months (range, 24-60 months). RESULTS: Ninety of 100 (90%) patients were able to compete at the same or a higher level than before medial ulnar collateral ligament injury for more than 12 months as noted at the follow-up interval; 7 patients were able to compete at a lower level. Only 3 patients suffered postoperative complications. CONCLUSION: The docking technique reliably returns athletes to competitive throwing with a low perioperative morbidity.     

Long term changes of the throwing arm of former elite javelin throwers.

The aim of this study was to determine long term changes in shoulder and elbow joints of former elite javelin throwers. Twenty-one elite javelin throwers were examined at an average of 19 years after the end of their high performance phase. Mean age at examination was 50 years. Functional assessment of both shoulders was determined by the Constant-score. The shoulder of the throwing arm was examined by magnetic resonance imaging. Both elbow joints were examined clinically and radiographically. Five athletes complained about transient shoulder pain in their throwing arm affecting activities of daily living, fourteen athletes had a deficit of internal rotation of at least ten degrees. Constant-scores of throwing arms were six points lower than those of non-throwing arms (P < 0.05). Complete ruptures and partial tears of the rotator cuff were frequent. Three athletes complained about transient elbow pain in their throwing arm affecting activities of daily living; ten athletes had a deficit of extension of more than five degrees. All dominant elbows had advanced arthrotic alterations (osteophytes, sclerosis) compared to the non-dominant side. Athletes who trained with weights of more than 3 kg had a significantly higher risk of degenerative changes than athletes who did not (P < 0.01). We therefore recommend to avoid throwing training with weights of more than 3 kg.     

Clinical impact of elbow magnetic resonance imaging

The elbow and its articulations are subject to tremendous forces during overhead sports. The elbow joint is vulnerable to a variety of injuries as a result of either acute traumatic events or chronic repetitive overuse. Elbow pathology in throwing athletes has been classified according to the mechanism of injury: medial tension overload, lateral compression, extension overload, and posterolateral rotatory instability. Given the complexity of these injuries, complete diagnosis and treatment requires a thorough evaluation of the elbow. This evaluation begins with a history and physical examination, an understanding of pathomechanics, and an assessment of normal and pathological anatomy. Imaging studies may be of assistance in defining this anatomy. The correlation of these imaging studies with clinical information is essential in the proper diagnosis and management of these complex injuries. This article presents the impact of elbow magnetic resonance imaging (MRI) for the clinical diagnosis of the three most common elbow disorders for which MRI has diagnostic efficacy in the athlete.     

MR and CT arthrography of the elbow

Magnetic resonance (MR) arthrography has, to a great extent, replaced conventional and CT arthrography as the standard of care imaging tool for indications including medial elbow pain in the throwing athlete, chondral and osteochondral lesions in the elbow, and intra-articular bodies. There are still rare specific incidences where CT arthrography is indicated. This article reviews elbow arthrography, with a greater emphasis placed on MR arthrography, including indications, technique, potential complications, contraindications, equipment, and MR arthrographic pathologies.     

Ulnar collateral ligament injury in baseball pitchers: MR imaging evaluation.

The ulnar collateral ligament (UCL) provides stability to the medial aspect of the elbow during valgus stress. Trauma to this ligament may result from repetitive forceful throwing. Diagnosis of UCL injury has been based on clinical findings of medial joint pain and valgus instability, as direct imaging of this structure has not been available. Eleven baseball pitchers with clinical evidence of UCL injury were evaluated with magnetic resonance (MR) imaging. Surgical correlation was obtained in six patients, four of whom underwent UCL reconstruction. MR imaging findings in UCL injury included laxity, irregularity, poor definition, and increased signal intensity within and adjacent to the UCL. These findings reflect the presence of hemorrhage and/or edema within the UCL due to repeated microtears, which eventually lead to weakening and possible disruption of the UCL. Optimization of spatial resolution, signal-to-noise ratio, and other technical factors is critical for evaluation of the UCL due to its small size. MR imaging is useful in documenting the presence and severity of injury to the UCL and in distinguishing this entity from other causes of elbow pain.     

Magnetic resonance imaging of the elbow in athletes

Acute and chronic elbow pain is common, particularly in athletes. Although plain radiographs, ultrasound, and computed tomography all have a role to play in the investigation of elbow pain, magnetic resonance imaging (MRI) has emerged as the imaging modality of choice for diagnosis of soft tissue disease and osteochondral injury around the elbow. The high spatial resolution, excellent soft-tissue contrast, and multiplanar imaging capabilities of MRI make it ideal for evaluating the complex joint anatomy of the elbow. This article reviews imaging of common disease conditions occurring around the elbow in athletes, with an emphasis on MRI.     

Osseous manifestations of elbow stress associated with sports activities

The radiographic manifestations of musculoskeletal stress at the elbow associated with racket and throwing sports are reported in 29 symptomatic amateur, juvenile, and professional athletes. Five major categories of stress are identified: diffuse, humeral shaft, medial tension, lateral compression, and extension stress. The osseous changes produced by these stresses include bony hypertrophy, loose bodies, traction spur formation, osteochondral and humeral shaft fractures in the adult, and epiphyseal and apophyseal hypermaturity or avulsion in the youngster.     

Osteochondral lesions of the humeral trochlea in the young athlete

Objective  The purpose of this study was to characterize the variety of osteochondral abnormalities of the humeral trochlea in the pediatric athlete. Materials and methods  Patients with trochlear abnormalities were identified through keyword search of radiology dictations from 1999 to 2007. The patient’s medical record, imaging studies, and surgical reports were reviewed. The osteochondral lesions were categorized based on the imaging appearance. Surgical results were reviewed in conjunction with the imaging findings. Results  Eighteen patients were identified. Trochlear lesions were stratified into two imaging groups: Osteochondral injury/osteochondritis dissecans (OCD) vs. avascular necrosis (AVN). The osteochondral injury group was stratified into medial and lateral trochlear abnormalities. The medial lesions (n = 3) were small (<6 mm) and were located on the posterior articular surface of the medial trochlea. The lateral lesions (n = 10) were larger (10–14 mm), circumscribed, and were located on the posterior inferior aspect of the lateral trochlea. Trochlear AVN (n = 5) affected development of the lateral trochlea (type A) or both the medial and lateral aspects of the trochlea (type B). AVN occurred exclusively in athletes with history of remote distal humeral fracture. Seven of the 18 patients underwent elbow arthroscopy. Surgical findings and treatment regimens are summarized. Conclusion  Trochlear lesions should be considered in throwing athletes presenting with medial elbow pain and flexion contracture/extension block. Medial trochlear osteochondral injuries may result from posteromedial olecranon abutment. Lateral OCD lesions occur in a characteristic vascular watershed zone resulting from the unique blood supply of the trochlea. Trochlear AVN may be unmasked years following treated distal humeral fracture when the athletic demands upon the adolescent elbow increase, revealing the altered growth and biomechanics.     

Elbow injuries in throwing athletes: a current concepts review

Repetitive overhead throwing imparts high valgus and extension loads to the athlete's elbow, often leading to either acute or chronic injury or progressive structural change. Tensile force is applied to the medial stabilizing structures with compression on the lateral compartment and shear stress posteriorly. Common injuries encountered in the throwing elbow include ulnar collateral ligament tears, ulnar neuritis, flexor-pronator muscle strain or tendinitis, medial epicondyle apophysitis or avulsion, valgus extension overload syndrome with olecranon osteophytes, olecranon stress fractures, osteochondritis dissecans of the capitellum, and loose bodies. Knowledge of the anatomy and function of the elbow complex, along with an understanding of throwing biomechanics, is imperative to properly diagnose and treat the throwing athlete. Recent advantages in arthroscopic surgical techniques and ligament reconstruction in the elbow have improved the prognosis for return to competition for the highly motivated athlete. However, continued overhead throwing often results in subsequent injury and symptom recurrence in the competitive athlete.     

Stress injuries to bone in college athletes: a retrospective review of experience at a single institution

BACKGROUND: No comprehensive studies have been published on stress injuries to bone in college athletes. PURPOSE: To review, in a college athlete population, the epidemiologic aspects of stress injuries to bone, and to examine a subset of patients who were treated with a uniform protocol for return to activities, with magnetic resonance imaging as the primary tool for diagnosis. STUDY TYPE: Retrospective review. METHODS: Ten years of medical records from a Division I college institution were reviewed. Location and grade of stress injury to bone and duration of disability were recorded. All injured athletes followed the same treatment program, with the exception of football players, who were excluded from the return to sport analyses. RESULTS: Seventy-four athletes had lower extremity symptoms consistent with stress injury to bone. Diagnosis was confirmed in 68 of these athletes, 61 via magnetic resonance imaging, 6 via positive radiographs only, and 1 via bone scan only. Distance runners accounted for the most stress injuries to bone for both men and women. The tibia (37%) was the most frequently involved bone; however, as an anatomic region, the foot (44%) was the site of the most stress injuries. There was a significant correlation between grade of injury and time to full return to activity. CONCLUSIONS: The grading system used at this institution is a standardized tool that can be used to predict time to return to sport. A standardized rehabilitation protocol allowed for an appropriate plan to return the athletes to pain-free competition.     

Return to australian rules football after acute elbow dislocation: A report of three cases and review of the literature

Acute elbow dislocation is an uncommon problem encountered in contact sports such as Australian Rules Football [ARF]. Previously there have been few guidelines presented as to when the athlete can safely return to sport following such an injury. During the 1998 playing season the author as medical officer of a professional ARF team encountered three athletes who had an elbow dislocation. All resulted from a fall on an outstretched hand during competition. The athletes returned to football at 13 days, 21 days and 7 days respectively. All subsequently completed the football season without re-injury and at post-season clinical review and one year subsequent to this no athlete described residual symptoms nor was there any loss of range of motion of the elbow joint. Clinical recommendations that allow for athletes to make a safe and early return to contact sport following an episode of acute elbow dislocation include; 1) commencing active mobilization as soon as possible after injury, 2) using passive mobilization to attain full extension as soon as possible, 3) allowing the athlete to return to training before full extension is achieved and 4) allowing the athlete to return to contact sport as soon as full extension is achieved with assistance of elbow stability taping.     

Mobility and stability adaptations in the shoulder of the overhead athlete: a theoretical and evidence-based perspective

Overhead athletes require a delicate balance of shoulder mobility and stability in order to meet the functional demands of their respective sport. Altered shoulder mobility has been reported in overhead athletes and is thought to develop secondary to adaptive structural changes to the joint resulting from the extreme physiological demands of overhead activity. Researchers have speculated as to whether these structural adaptations compromise shoulder stability, thus exposing the overhead athlete to shoulder injury. Debate continues as to whether these altered mobility patterns arise from soft-tissue or osseous adaptations within and around the shoulder. Researchers have used quantitative techniques in an attempt to better characterize these structural adaptations in the shoulders of overhead athletes. Throwing athletes have been shown to display altered rotational range of motion (ROM) patterns in the dominant shoulder that favour increased external rotation and limited internal rotation ROM. Throwers also show a loss of horizontal or cross-body adduction in the throwing shoulder when compared with the non-throwing shoulder. This posterior shoulder immobility in the throwing shoulder is thought by some researchers to be associated with reactive scarring or contracture of the periscapular soft-tissue structures (e.g. posterior capsule and/or cuff musculature); however, evidence of reactive scarring or contractures of the posterior-inferior capsule or cuff musculature from anatomic or noninvasive imaging studies is lacking. Conversely, translational ROM (laxity) has been consistently shown to be symmetric between dominant and non-dominant shoulders of overhead athletes.From a skeletal perspective, throwing shoulders are shown to have more humeral retroversion when compared with the non-throwing shoulder. Alterations in humeral retroversion are thought to develop over time in young pre-adolescent throwers when the proximal humeral epiphysis is not yet completely fused. Even though the evidence is inconclusive at the present time, there is more compelling evidence that leads us to believe that altered shoulder mobility in the overhead-throwing athlete is more strongly associated with adaptive changes in proximal humeral anatomy (i.e. retroversion) than to structural changes in the articular and periarticular soft tissue structures. In addition, this retroversion is thought to account for the observed shift in the arc of rotational ROM in overhead athletes. However, in some athletes, capsulo-ligamentous adaptations such as anterior-inferior stretching or posterior-inferior contracture may become superimposed upon the osseous changes. This may ultimately lead to pathological manifestations such as secondary impingement, type II superior labrum from anterior to posterior (SLAP) lesions and/or internal (glenoid) impingement.Overuse injuries in the overhead athlete are a common and perplexing clinical problem in sports medicine and, therefore, it is imperative for sports medicine clinicians to have a thorough understanding of the short- and long-term effects of overhead activity on the shoulder complex. It is our intention that the information presented will serve as a guide for clinicians who treat the shoulders of overhead athletes.     

Rotator cuff contusions of the shoulder in professional football players: epidemiology and magnetic resonance imaging findings

BACKGROUND: No published reports have studied the epidemiology and magnetic resonance imaging findings associated with rotator cuff contusions of the shoulder in professional football players. PURPOSE: To determine a single professional football team's incidence, treatment, and magnetic resonance imaging appearance of players sustaining rotator cuff contusions of the shoulder. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From 1999 to 2005, a North American professional football team's injury records were retrospectively reviewed for athletes who had sustained a rotator cuff contusion of the shoulder during in-season participation. Those patients who had magnetic resonance imaging of the shoulder with a 1.5-Tesla magnet were reviewed by a musculoskeletal radiologist and graded according to the appearance and severity of clinical injury. RESULTS: Twenty-six players had a rotator cuff contusion. There was an average of 5.5 rotator cuff contusions per season (47% of all shoulder injuries). The predominant mechanism of injury was a direct blow in 70.3%. Magnetic resonance imaging findings included peritendon edema at the myotendinous junction, critical zone tendon edema, and subentheseal bone bruises. Treatment consisted of a protocol involving modalities and cuff rehabilitation in all patients. Six patients had persistent pain and weakness for a minimum of 3 days and were given a subacromial corticosteroid injection. Overall, 3 patients (11.4%) required later surgical treatment on the shoulder. CONCLUSION: Rotator cuff contusions accounted for nearly half of all shoulder injuries in the football players in this study. Magnetic resonance imaging is an extremely useful tool in determining severity of injury and integrity of the rotator cuff. The majority of athletes are able to return to sports with conservative treatment; a minority of shoulders might progress to more severe injuries such as rotator cuff tears.     

Medial collateral ligament reconstruction of the elbow using the docking technique

BACKGROUND: Medial collateral ligament insufficiency of the elbow with resultant valgus instability in throwing athletes is typically treated with free tendon graft reconstruction as described by Jobe. HYPOTHESIS: Improved results could be obtained with the use of the docking technique. STUDY DESIGN: Uncontrolled retrospective review. METHODS: The study group consisted of 36 athletes who had symptomatic insufficiency of the medial collateral ligament confirmed by magnetic resonance imaging and by surgical findings. Average follow-up was 3.3 years. Key elements of the docking technique included a muscle-splitting approach without routine transposition of the ulnar nerve, routine arthroscopic assessment, treatment of associated lesions, and docking the two ends of the tendon graft into a single humeral tunnel. RESULTS: Thirty-three of 36 patients (92%) returned to or exceeded their previous level of competition for at least 1 year, meeting the Conway-Jobe classification criteria of "excellent." All 22 professional or collegiate athletes returned to or exceeded their previous competition level. CONCLUSIONS: The docking technique allowed simplified graft tensioning and improved graft fixation.