Magnetic resonance imaging of the elbow: update on current techniques and indications

Medial Ulnar Collateral Ligament Injuries in Contact Athletes

PURPOSE OF REVIEW

The purpose of this article is to review medial ulnar collateral ligament (UCL) injuries in contact athletes. UCL injuries in overhead throwing athletes are typically chronic attenuation due to repetitive valgus stress on the elbow during the throwing motion. As such, UCL reconstruction is commonly performed for these athletes. In contrast, UCL injuries in contact athletes are usually acute ligament tears or avulsions of a ligament with otherwise normal tissue. Nonoperative treatment is typically the first-line treatment for partial injuries. UCL repair may work well for acute complete injuries and may avoid the donor site morbidity of UCL reconstruction.

RECENT FINDINGS

Most of the literature regarding UCL injuries have been performed in baseball players. Historically, UCL repair has had poor outcomes in baseball players due to the chronic ligament attenuation. Therefore, much of the recent literature has focused on outcomes of UCL reconstruction, which are generally excellent. However, there is a paucity of literature studying outcomes of UCL injuries in contact athletes and those studying UCL repair. One recent study looked at a new technique for UCL repair with collagen-coated fiber tape augmentation in baseball players and found good short-term outcomes. UCL injuries in contact athletes occur typically as acute tears or avulsions. While UCL reconstruction has typically been recommended as the accepted treatment for UCL tears that require operative treatment, UCL repair may be a good alternative in contact athletes.

Ultrasound Examination Techniques for Elbow Injuries in Overhead Athletes

Elbow pain is a frequent complaint among overhead athletes. Standard evaluation of the elbow uses history and physical examination, with radiographic imaging and MRI aiding in the confirmation of diagnosis. Musculoskeletal ultrasonography (US) provides dynamic, functional assessment of tendons and ligaments in the elbow, allowing the visualization of structures under stress and motion. Stress US offers the ability to detect injuries to the ulnar collateral ligament by measuring changes in joint space under stress. The freedom of dynamic imaging means results are dependent on the skill of the US operator to obtain the most accurate and complete evaluation. US is cost efficient and portable, allowing for quick examination at the point of care. This article provides a technique guide for sports medicine specialists performing US examination of the elbow.

Valgus stress ultrasound for medial ulnar collateral ligament injuries in athletes: is ultrasound alone enough for diagnosis?

BACKGROUND

We hypothesized that valgus stress ultrasound would be useful for both identifying medial ulnar collateral ligament (MUCL) tears and assessing the severity of the tears. Hence, we performed valgus stress ultrasound of the elbow in athletes with MUCL injuries, confirmed by magnetic resonance imaging (MRI), to determine whether ultrasound can be used as a diagnostic tool.

METHODS

Stress ultrasound and MRI data from 146 athletes with medial elbow pain were compared prospectively. MRI findings for MUCL injuries were classified into 3 levels as follows: low-grade partial tear (≤50%), high-grade partial tear (>50%), and complete tear. The degree of joint laxity on stress ultrasound was evaluated by measuring joint gapping after applying a 2.5-kg load to the wrist. Joint gapping was measured at 30° and 90° of elbow flexion for the dominant arm and nondominant arm, and the differences between the dominant and nondominant arms were determined.

RESULTS

A higher degree of MUCL injury on MRI was associated with greater joint gapping in the medial elbow on stress ultrasound. At 30° of elbow flexion, the cutoff value for complete MUCL rupture was 0.5 mm (P < .001), with a sensitivity and specificity of 88.1% and 61.5%, respectively. At 90° of elbow flexion, the cutoff value for complete MUCL rupture was 1.0 mm (P < .001), with a sensitivity and specificity of 81.0% and 66.4%, respectively.

CONCLUSION

Stress ultrasound can be used to diagnose complete MUCL tears in athletes when joint gapping is greater than 0.5 mm at 30° of elbow flexion and greater than 1 mm at 90° of elbow flexion.

Anatomic Study of the Elbow Joint in a Bengal Tiger (Panthera tigris tigris) Using Magnetic Resonance Imaging and Gross Dissections

The objective of our research was to describe the normal appearance of the bony and soft tissue structures of the elbow joint in a cadaver of a male mature Bengal tiger (Panthera tigris tigris) scanned via MRI. Using a 0.2 Tesla magnet, Spin-echo (SE) T1-weighting, and Gradient-echo short tau inversion recovery (GE-STIR), T2-weighting pulse sequences were selected to generate sagittal, transverse, and dorsal planes. In addition, gross dissections of the forelimb and its elbow joint were made. On anatomic dissections, all bony, articular, and muscular structures could be identified. The MRI images allowed us to observe the bony and many soft tissues of the tiger elbow joint. The SE T1-weighted MR images provided good anatomic detail of this joint, whereas the GE-STIR T2-weighted MR pulse sequence was best for synovial cavities. Detailed information is provided that may be used as initial anatomic reference for interpretation of MR images of the Bengal tiger (Panthera tigris tigris) elbow joint and in the diagnosis of disorders of this region.

Using Stress Ultrasonography to Understand the Risk of UCL Injury Among Professional Baseball Pitchers Based on Ligament Morphology and Dynamic Abnormalities

Background:

Ulnar collateral ligament (UCL) injury of the elbow is a common and debilitating problem seen frequently among elite baseball pitchers. Ultrasound is a useful diagnostic tool in evaluating UCL injuries.

Hypothesis:

Evaluation with stress ultrasound of the elbow to measure the morphology of the UCL and the ulnohumeral joint space gapping is indicative of higher risk of UCL injury among professional baseball pitchers.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

Ultrasound imaging was used to assess the medial joint laxity of the elbow of 70 asymptomatic professional baseball pitchers during spring training. Medial joint laxity and UCL morphology were assessed with OsiriX imaging software under 2 conditions—gravity valgus load and 5.5 lb of valgus load per a handheld dynamometer—with the shoulder in the maximal cocking position and the elbow in 90° of flexion. Two trials of resting position, elbow gapping, and UCL thickness were collected, measured, and averaged for data analysis. Intra- and interrater reliabilities were established and maintained, with intraclass correlation coefficients in the acceptable range for all measures (0.84-0.99). One-way analysis of variance was used to compare dominant variables between those pitchers who sustained a subsequent UCL injury and those who did not. A receiver operating curve was used to identify pitchers who, based on elbow gapping measures (by cut score), were at high risk versus low risk for UCL injury.

Results:

Players who went on to injure the UCL (n = 7) displayed a significantly wider opening under 5.5 lb of applied stress (6.5 ± 1.2 vs 5.3 ± 1.2 mm, P = .01) when compared with pitchers without UCL injury history (n = 63); they also presented a trend toward wider dominant arm resting joint opening (4.9 ± 1.2 vs 4.0 ± 1.1 mm, P = .07). Professional pitchers with valgus stress ulnohumeral joint gapping ≥5.6 mm (area underneath the curve, 0.77; P = .02) of the dominant arm were at a 6-times greater risk of sustaining a UCL tear requiring reconstruction within a season.

Conclusion:

Our data suggest that ultrasound evaluation of UCL morphology may be indicative of pitchers who are at risk of sustaining UCL injury and that it may improve player assessment.

Correlation of MRI to Arthroscopy in the Elbow: Thrower's Elbow and Ulnar Collateral Ligament Injury

One cannot overstate the importance of a thorough history and physical examination, supplemented with directed imaging, to help pinpoint the exact cause of the athlete's elbow pain. Although plain radiographs should not be overlooked, advanced imaging plays a critical role in diagnosis and management of pathology in the thrower's elbow, including computed tomography, magnetic resonance imaging, and stress ultrasound. By judiciously combining these elements, the clinician can appropriately manage these injuries in order to successfully return the athlete to their preinjury level of play.

Stress ultrasound in baseball players with ulnar collateral ligament injuries: additional value for predicting rehabilitation outcome

BACKGROUND

The purpose of this study was to evaluate the additional value of stress ultrasound (US) for predicting rehabilitation outcome in baseball players with ulnar collateral ligament (UCL) injury.

METHODS

Stress US and magnetic resonance imaging (MRI) in 41 baseball players with UCL injury who received rehabilitation treatment for more than 6 weeks were retrospectively compared between the rehabilitation group (n = 23) and surgery group (n = 18). The MRI grade of UCL injury was assessed as intact continuity, low-grade partial tear, high-grade partial tear, and complete tear. To estimate sonographic joint laxity, we assessed 3 sonographic criteria as present or absent: ligamentous waviness, joint gapping, and intra-articular ring-down artifact. In addition, the presence of concomitant tenderness was checked during stress US. The diagnostic validity of MRI with and without stress US was analyzed as a predictor for the rehabilitation outcome.

RESULTS

The MRI grade was higher in the surgery group than in the rehabilitation group (P < .001). Sonographic joint laxity showing the ring-down artifact and concomitant tenderness with stress were significantly more frequent in the surgery group (P = .024 and P = .006, respectively). Sensitivity, specificity, and accuracy were 61.1%, 86.9%, and 75.6%, respectively, for MRI alone and 83.3%, 56.5%, and 68.2%, respectively, for the combination of MRI with joint laxity showing the ring-down artifact. For MRI in combination with joint laxity and concomitant tenderness, these values were 72.2%, 82.6%, and 78.0%, respectively.

CONCLUSION

The addition of stress US showing the ring-down artifact and concomitant tenderness was helpful for predicting the rehabilitation outcome of UCL injuries.

Primary Elbow Osteoarthritis: An Updated Review

Primary elbow arthritis predominantly affects middle aged men undertaking heavy manual work. Patients present with pain and limited movement but may also complain of ulnar nerve sensory or motor symptoms. Radiographic features include osteophytes at the tip of the olecranon and coronoid processes, loose bodies, narrowing of the radiocapitellar joint space and thickening of the olecranon fossa membrane. Treatment options range from conservative management using oral analgaesics and non-steroidal anti-inflammatory drugs through to open debridement procedures, arthroscopy and occasionaly in selected patients total elbow arthroplasty.

Stress ultrasound evaluation of medial elbow instability in a cadaveric model

BACKGROUND

An injury of the ulnar collateral ligament (UCL) is potentially career threatening for elite overhead-throwing athletes. Stress ultrasonography (SUS) allows for a rapid, cost-effective, and noninvasive evaluation of the UCL and elbow joint both at rest and with applied stress.

PURPOSE/HYPOTHESIS

To determine the amount of cadaveric elbow valgus gapping with sequential sectioning of medial elbow structures as measured by SUS. It was hypothesized that the greatest increase in ulnohumeral joint gapping would be noted with release of the anterior bundle of the UCL.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twelve cadaveric elbows were divided into 2 groups and dissected in reverse sequences under the direct supervision of an experienced orthopaedic surgeon. Baseline ultrasound and SUS with applied valgus loads were performed by an experienced radiologist. A valgus load was applied at each sectioning interval using a standardized device. Ulnohumeral joint gapping in millimeters was measured by SUS for each step as the width of the medial joint from the trochlea to the sublime tubercle. The mean increases in joint gapping (Δ) between each step were calculated to quantify the additional gapping achieved with release of each sequential stabilizer.

RESULTS

Release of the anterior band of the anterior bundle resulted in a mean Δ of 2.0 mm (95% CI, 1.1-2.8 mm). Release of the posterior band of the anterior bundle resulted in a mean Δ of 1.4 mm (95% CI, 0.6-2.2 mm). Release of the entire anterior bundle caused a mean increase in ulnohumeral valgus joint gapping of 3.4 mm (95% CI, 2.4-4.3 mm). Release of the remaining individual structures each resulted in a mean increase in valgus joint gapping of ≤0.8 mm.

CONCLUSION

The results of the current cadaveric study suggest that different amounts of gapping are seen on SUS with sectioning of the medial elbow stabilizers. The hypothesis was confirmed with release of the anterior bundle of the UCL resulting in the greatest increase in joint gapping as measured by SUS.

CLINICAL RELEVANCE

This study illustrates that SUS can identify the contributions of each anatomic portion of the UCL and the flexor-pronator mass to ulnohumeral joint stability in a cadaveric model.

Stress sonography of the ulnar collateral ligament of the elbow in professional baseball pitchers: a 10-year study

BACKGROUND

An injury to the ulnar collateral ligament (UCL) of the elbow is potentially career threatening for elite baseball pitchers. Stress ultrasound (US) of the elbow allows for evaluation of both the UCL and the ulnohumeral joint space at rest and with stress.

HYPOTHESIS

Stress US can identify morphological and functional UCL changes and may predict the risk of a UCL injury in elite pitchers.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 368 asymptomatic professional baseball pitchers underwent preseason stress US of their dominant and nondominant elbows over a 10-year period (2002-2012). Stress US examinations were performed in 30° of flexion at rest and with 150 N of valgus stress by a single musculoskeletal radiologist. Ligament thickness, ulnohumeral joint space width, and ligament abnormalities (hypoechoic foci and calcifications) were documented.

RESULTS

There were 736 stress US studies. The mean UCL thickness in the dominant elbow (6.15 mm) was significantly greater than that in the nondominant elbow (4.82 mm) (P < .0001). The mean stressed ulnohumeral joint space width in the dominant elbow (4.56 mm) was significantly greater than that in the nondominant elbow (3.72 mm) (P < .02). In the dominant arm, hypoechoic foci and calcifications were both significantly more prevalent (28.0% vs 3.5% and 24.9% vs 1.6%, respectively; P < .001). In the 12 players who incurred a UCL injury, there were nonsignificant (P > .05) increases in baseline ligament thickness, ulnohumeral joint space gapping with stress, and incidence of hypoechoic foci and calcifications. More than 1 stress US examination was performed in 131 players, with a mean increase of 0.78 mm in joint space gapping with subsequent evaluations.

CONCLUSION

Stress US indicates that the UCL in the dominant elbow of elite pitchers is thicker, is more likely to have hypoechoic foci and/or calcifications, and has increased laxity with valgus stress over time.

Correlation of preoperative MRI and MRA with arthroscopically proven articular cartilage lesions of the elbow

OBJECTIVE

The purpose of this study was to evaluate the usefulness of magnetic resonance imaging (MRI) in detecting elbow articular cartilage injuries through comparison of preoperative MRI and magnetic resonance arthrography (MRA) with arthroscopic findings.

DESIGN

Retrospective case analysis.

SETTING

Tertiary care orthopedic private practice.

PATIENTS

Consecutive series of 31 patients presenting with elbow pain and diagnosed at arthroscopy with articular cartilage defects of the elbow. All patients had a preoperative MRI or MRA using a 1.5 T magnet.

INTERVENTIONS

Each patient had a systematic elbow arthroscopy, with careful inspection and recording of chondral injuries in 4 anatomical regions: capitellum, radius, trochlea, and ulna. Each MRI/MRA was then independently reviewed by 2 radiologists blinded to the arthroscopic findings.

MAIN OUTCOME MEASURES

The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were calculated for MRI and MRI compared with arthroscopy as the gold standard, for each of the anatomical regions.

RESULTS

The accuracy of MRI was 45% for chondral injuries of the radius, 65% for the capitellum, 20% for the ulna, and 30% for the trochlea. The accuracy of MRA was 45% for chondral injuries of the radius, 64% for the capitellum, 18% for the ulna, and 27% for the trochlea.

CONCLUSION

We conclude that the ability of MRI and MRA using a 1.5 T magnet to detect articular cartilage lesions is limited. Neither MRI nor MRA demonstrates the intraarticular surface as accurately as direct visualization with the arthroscopy. This may be improved with the use of 3 T MRI.

CLINICAL RELEVANCE

This study demonstrates that MRI and MRA with a 1.5 T magnet, as used in community practice, have limited ability to detect cartilage lesions of the elbow.

Magnetic resonance imaging in radial head fractures: most associated injuries are not clinically relevant

BACKGROUND

Recent studies report that magnetic resonance imaging (MRI) shows a high incidence of associated injuries in patients with a radial head fracture. This retrospective study describes the clinical relevance of these injuries.

MATERIALS AND METHODS

Forty patients with 42 radial head fractures underwent a MRI scan after a mean of 7.0 days after trauma and were reviewed after a mean of 13.3 months.

RESULTS

MRI showed 24 of 42 elbows had a lateral collateral ligament (LCL) lesion, 1 had a medial collateral ligament (MCL) and LCL lesion, 16 had an injury of the capitellum, 1 had a coronoid fracture, and 2 had loose osteochondral fragments. Clinical evaluation after a mean of 13.3 months showed that 3 elbows had clinical MCL or LCL laxity, of which 2 elbows had no ligamentous injuries diagnosed with MRI. One elbow with a loose osteochondral fragment showed infrequent elbow locking. The mean Mayo Elbow Performance Scale was 97.5 (range, 80-100) after a mean of 13.3 months after trauma, with no significant difference between patients with and without associated injuries (P = .8).

CONCLUSION

Most injuries found with MRI in patients with radial head fractures are not symptomatic or of clinical importance in short-term follow-up.

The detection of the capsular tear at the undersurface of the extensor carpi radialis brevis tendon in chronic tennis elbow: the value of magnetic resonance imaging and computed tomography arthrography

HYPOTHESIS

This study compared the diagnostic efficacy of magnetic resonance imaging (MRI) and computed tomography arthrography (CTA) in the assessment of capsular tears at the undersurface of the extensor carpi radials brevis tendon in chronic tennis elbow using arthroscopy as a gold standard. Because of the higher spatial resolution of CT, we hypothesized that CTA is superior to MRI for assessing capsular tears.

MATERIALS AND METHODS

We retrospectively reviewed 19 consecutive patients with chronic tennis elbow with preoperative MRI and CTA studies who underwent arthroscopic surgery. Three observers with different levels of training and experience (musculoskeletal radiologist, experienced elbow surgeon, and hand fellow) evaluated the capsular tear by MRI and CTA in a blinded manner. The results of the MRI and CTA were compared and the agreement among the 3 observers was determined using an intraclass correlation coefficient (ICC). Then, the results of the MRI and CTA examinations were compared with the intraoperative findings of the arthroscopic examination. The sensitivity, specificity, and κ value were calculated.

RESULTS

The ICC of CTA (0.855) was superior to MRI (0.645). The sensitivity, specificity, and κ value of CTA were superior to those of MRI in each of the 3 observers. The κ value was 0.79, 0.89, and 0.79 for CTA, and 0.48, 0.48, and 0.27 for MRI for the radiologist, surgeon, and fellow, respectively.

CONCLUSIONS

CTA was a reliable and accurate diagnostic modality compared with MRI to detect the capsular tear in patients with chronic tennis elbow. CTA was less influenced by the observer's experience.

Osteochondritis dissecans of the capitellum: a review of the literature and a distal ulnar portal

Osteochondritis dissecans (OCD) of the humeral capitellum most commonly affects young athletes engaged in sports that repetitively stress the elbow. It is characterized by localized injury of subchondral bone of the humeral capitellum. To determine the best treatment option for OCD in young athletes, it is important to differentiate between stable and unstable OCD lesions. Stable lesions can be treated with rest, whereas unstable lesions, as well stable lesions that do not respond to conservative therapy, may require a surgical approach. Magnetic resonance imaging is the diagnostic study of choice to evaluate capitellar OCD lesions and loose bodies and to accurately determine the stability and viability of the OCD fragment. A variety of surgical approaches have been reported, from internal fixation of large fragments to autologous chondrocyte grafts. Arthroscopic surgery is becoming the standard treatment of capitellar OCD. This minimally invasive approach shows good results, a low risk of operative morbidity, and early recuperation postoperatively. The distal ulnar portal we describe here allows for ergonomic exposure to the posterolateral capitellum, providing easier access for drilling, burring, and local debridement of lesions amenable to arthroscopy.

The posterior transtriceps approach for elbow arthrography: a forgotten technique?

OBJECTIVE

To evaluate the technical feasibility of performing elbow MR arthrography via a posterior approach through the triceps.

MATERIALS AND METHODS

The images of 19 patients with elbow MR arthrography via a posterior transtriceps approach were retrospectively studied. The injections were performed by four musculoskeletal radiologists, using fluoroscopic guidance and a 22- or 25-gauge needle. The fluoroscopic and subsequent MR images were reviewed by two musculoskeletal radiologists and evaluated for adequacy of joint capsular distention, degree and location of contrast leakage, and presence of gas bubbles.

RESULTS

The injection was diagnostic in all 19 patients, with a sufficient amount of contrast agent seen in the elbow joint. No significant contrast leakage occurred in 12 patients who received injections of 8 cc or less of contrast agent, but moderate contrast leakage occurred in 6/7 patients who received injections of greater than 8 cc. Contrast leakage generally occurred within the triceps myotendinous junction. No gas bubbles were identified in the injected joints.

CONCLUSION

Patients often present for MR arthrography of the elbow with medial or lateral elbow pain. Contrast leakage during a radiocapitellar approach may complicate evaluation of the lateral collateral ligament or the common extensor tendon origin. Transtriceps MR arthrography offers an alternative to the more commonly used radiocapitellar approach. With injected volumes not exceeding 8 cc, the risk of significant contrast leakage is small. An advantage of the transtriceps injection is that contrast leakage through the posterior needle tract does not interfere with evaluation of the lateral structures.

Detection of calcium phosphate crystals in the joint fluid of patients with osteoarthritis - analytical approaches and challenges

Clinically, osteoarthritis (OA) is characterised by joint pain, stiffness after immobility, limitation of movement and, in many cases, the presence of basic calcium phosphate (BCP) crystals in the joint fluid. The detection of BCP crystals in the synovial fluid of patients with OA is fraught with challenges due to the submicroscopic size of BCP, the complex nature of the matrix in which they are found and the fact that other crystals can co-exist with them in cases of mixed pathology. Routine analysis of joint crystals still relies almost exclusively on the use of optical microscopy, which has limited applicability for BCP crystal identification due to limited resolution and the inherent subjectivity of the technique. The purpose of this Critical Review is to present an overview of some of the main analytical tools employed in the detection of BCP to date and the potential of emerging technologies such as atomic force microscopy (AFM) and Raman microspectroscopy for this purpose.