MR IMAGING OF LIGAMENTOUS ABNORMALITIES OF THE ELBOW

Isolated complete ulnar collateral ligament tear of the elbow in a gymnast: does it need surgery?

Ulnar collateral ligament (UCL) tears can occur from trauma or chronic overuse, and the treatment depends on the type of sport the patient plays and the severity of symptoms. Overuse UCL injuries are most commonly due to micro-trauma in overhead athletes such as baseball players, softball players, and tennis players. Acute complete UCL tears in athletes due to trauma are less common but generally operative treatment is recommended. In gymnastics, elbow dislocations are more common than isolated UCL injuries, and there is sparse literature on the success of non-operative treatment of isolated UCL injuries in this group of athletes. In this case report, we report a high-level competitive gymnast with an UCL tear and a partial tear of the forearm flexor mass, which was confirmed by a thorough careful physical examination and magnetic resonance imaging. The patient was treated non-operatively and successfully returned to gymnastics without symptoms. This case supports the suggestion that UCL tears of the elbow can be treated successfully in some gymnasts without surgery, and that treatment should be individualized in this group of athletes.

Magnetic resonance imaging of the elbow: a structured approach

CONTEXT

The elbow is a complex joint and commonly injured in athletes. Evaluation of the elbow by magnetic resonance imaging (MRI) is an important adjunct to the physical examination. To facilitate accurate diagnosis, a concise structured approach to evaluation of the elbow by MRI is presented.

EVIDENCE ACQUISITION

A PubMed search was performed using the terms elbow and MR imaging. No limits were set on the range of years searched. Articles were reviewed for relevance with an emphasis of the MRI appearance of normal anatomy and common pathology of the elbow.

RESULTS

The spectrum of common elbow disorders varies from obvious acute fractures to chronic overuse injuries whose imaging manifestations can be subtle. MRI evaluation should include bones; lateral, medial, anterior, and posterior muscle groups; the ulnar and radial collateral ligaments; as well as nerves, synovium, and bursae. Special attention should be paid to the valgus extension overload syndrome and the MRI appearance of associated injuries when evaluating throwing athletes.

CONCLUSION

MRI evaluation of the elbow should follow a structured approach to facilitate thoroughness, accuracy, and speed. Such an approach should cover bone, cartilage, muscle, tendons, ligaments, synovium, bursae, and nerves.

The appearance of the lateral ulnar collateral ligament on magnetic resonance imaging

The lateral ulnar collateral ligament is an important element of the elbow's lateral capsuloligamentous complex, and loss of integrity contributes to posterolateral rotatory instability. However, the normal appearance on magnetic resonance imaging is poorly defined. The purpose of this study was to assess the appearance of the lateral ulnar collateral ligament of asymptomatic elbows on magnetic resonance imaging. We performed magnetic resonance imaging on 20 asymptomatic elbows. The lateral ulnar collateral ligament was identified as a hypointense structure originating from the lateral epicondyle and inserting on the proximal ulna in 10 cases (50%) and was ambiguous in the other 10 elbows. The identified lateral ulnar collateral ligament images included areas of high signal intensity, which was confusing because it suggested ligamentous disruption within the ligament. These results indicate that magnetic resonance imaging is not reliable for diagnosing lateral ulnar collateral ligament injuries at the present time. Further progress in magnetic resonance imaging will be clinically useful for diagnosing abnormalities of the lateral ulnar collateral ligament.

Lateral ulnar collateral ligament of the elbow: optimization of evaluation with two-dimensional MR imaging

PURPOSE

To compare, in a cadaveric model, magnetic resonance (MR) imaging techniques with differing contrast and spatial resolution properties in the evaluation of disruption of the lateral ulnar collateral ligament (LUCL) at the elbow.

MATERIALS AND METHODS

LUCL tears were surgically created in eight of 28 cadaveric elbow specimens. All specimens underwent 1.5-T MR imaging with the following pulse sequences: T1-weighted spin echo (SE), intermediate-weighted fast SE, fat-suppressed T2-weighted fast SE, gradient-recalled echo (GRE) with high spatial resolution, intermediate-weighted fast SE with high spatial resolution, and fat-suppressed T1-weighted SE with intraarticular administration of gadopentetate dimeglumine (MR arthrography). All images were obtained in the oblique coronal plane. Two radiologists independently graded the LUCL with separate and side-by-side assessment.

RESULTS

Areas under the receiver operating characteristic curve were as follows for readers A and B, respectively: T1-weighted SE imaging, 0.64 and 0.62; intermediate-weighted fast SE imaging, 0.87 and 0.67; T2-weighted fast SE imaging, 0.68 and 0.69; GRE imaging, 0.56 and 0.68; MR arthrography, 0.84 and 0.85; and intermediate-weighted imaging with high spatial resolution, 0.92 and 0.88. Interobserver reliability was poor with T1-weighted SE imaging (kappa = 0.13) and GRE imaging (kappa = 0.18), fair with T2-weighted fast SE imaging (kappa = 0.36), and moderate with MR arthrography (kappa = 0.46), intermediate-weighted fast SE imaging (kappa = 0.55), and intermediate-weighted imaging with high spatial resolution (kappa = 0.59).

CONCLUSION

Intermediate-weighted imaging with high spatial resolution and MR arthrography showed the greatest overall ability to enable the diagnosis of LUCL tears.