Faculty Bibliography

OBJECTIVE: The usefulness of MRI in costal cartilage injuries has not been shown. We report the MRI findings in a series of patients with costal cartilage injuries. CONCLUSION: MRI can be a useful technique in the diagnosis of costal cartilage injuries

PURPOSE: To retrospectively evaluate the appearance of lesions of osseous and soft-tissue structures of the glenohumeral joint on magnetic resonance (MR) images after first-time traumatic posterior shoulder dislocation. MATERIALS AND METHODS: The study was institutional review board approved and HIPAA compliant, as appropriate, for the four institutions at which the involved patients were treated. Informed patient consent was obtained, were applicable. Thirty-six male patients (age range, 15-80 years; mean age, 40.2 years) with clinically documented first-time traumatic posterior shoulder dislocation were examined with MR arthrography (18 patients) or conventional shoulder MR imaging (18 patients). Causes of posterior shoulder dislocation were electric shock in one patient, seizure in one patient, and trauma in 34 patients. Hill-Sachs lesions, rotator cuff tears, biceps tendon abnormalities, posterior labrocapsular complex lesions, humeral head translation, and osseous glenoid version angle were evaluated. Spearman rank correlation and Student t test analyses were performed. RESULTS: In 31 (86%) of the 36 patients, a reverse Hill-Sachs lesion was found. Eleven (31%) patients had a reverse osseous Bankart lesion. Twelve full-thickness rotator cuff tears were seen in seven (19%) patients: four supraspinatus tendon, three infraspinatus tendon, and five subscapularis tendon tears. Six (17%) patients had biceps tendon abnormalities. Posterior labrocapsular complex tears were identified in 21 (58%) patients: 10 (48%) with posterior labral sleeve avulsions and 11 (52%) with reverse Bankart lesions. Twenty-seven (75%) patients had a retroverted scaphoglenoid angle (mean, 4.5 degrees ). The mean humeral translation distance relative to the osseous glenoid fossa was -4.8 mm; in 33 (92%) patients, this distance was translated posteriorly. CONCLUSION: The MR appearance of traumatic posterior shoulder dislocation was characterized by reverse Hill-Sachs lesions in 86% of patients and posterocaudal labrocapsular lesions in nearly 60% of patients. Full-thickness rotator cuff tears were seen in approximately 20% of patients

We report a case of a 47-year-old man who presented with progressive loss of motion and pain in the right shoulder. Radiographs of the shoulder demonstrated dense ossification in the glenoid and humeral head with extension into the periarticular soft tissues. CT and MRI scans confirmed the radiographic findings and also revealed ossification of the glenoid labrum. A radiographic diagnosis of melorheostosis, an uncommon benign sclerosing bone dysplasia, was made. Because of the patient's severe symptomatology, he underwent total shoulder arthroplasty. Histological analysis of the resected masses was consistent with melorheostosis with a few areas covered by a cartilage cap. This case illustrates several uncommon but important features of melorheostosis, including mechanical obstruction of joint motion requiring joint replacement, ossification of the glenoid labrum, and cartilage-covering portions of the intra-articular masses, not to be confused with cartilage-producing tumors

OBJECTIVES: The objective was to retrospectively determine the prevalence and patterns of iliopsoas injuries based on consecutive MRI examinations, correlated with clinical findings. MATERIALS AND METHODS: From 4,862 consecutive MRI examinations of the hips and pelvis, 32 patients with 33 iliopsoas injuries were identified and graded as muscle strain, partial tendon tear, and complete tendon tears. These patients' medical records were reviewed to determine age, gender, and cause of symptoms. RESULTS: The prevalence of iliopsoas tendon and myotendinous injuries was 0.66% (95% CI: 0.44-0.89). There were 18 females and 14 males whose ages ranged from 7 to 95 years (mean, 54 years). The most frequent presenting symptom was hip pain and the most frequent clinical diagnosis, an occult fracture. The most common injuries in patients under 65 years (16 patients) were muscle strains and partial tendon tears, most often due to an athletic injury. The most common injury in patients 65 years and older (16 patients) was a complete tear (8 patients, all females), 2 of which were spontaneous in origin. CONCLUSIONS: Each grade of iliopsoas injury occurred with similar frequency. The more advanced the age of the patient, the more severe the injury. Non-athletic injuries predominated in patients 65 years and older; athletic injuries were the most common cause of iliopsoas injury in patients under 65 years

PURPOSE: To describe the magnetic resonance imaging (MRI) appearances of tears of the deltoid muscle and tendon in patients with rotator cuff tears and without a prior history of shoulder surgery. MATERIALS AND METHODS: Deltoid tears diagnosed on MR examinations were prospectively recorded between February 2003 through June 2004. The images of these patients were then retrospectively reviewed to determine the location of the deltoid tear, the presence of rotator cuff tears, tendon retraction, muscle atrophy, degree of humeral head subluxation, bony erosive changes involving the undersurface of the acromion, and the presence of edema or fluid-like signal intensity in the deltoid muscle and overlying subcutaneous tissues. RESULTS: There were 24 (0.3%) patients with deltoid tears; nine men and 15 women. The age range was 54 to 87 (average 73) years. The right side was involved in 20 cases, and the left in four cases. Fifteen patients had full thickness and nine had partial thickness tears of the deltoid. Shoulder pain was the most common presenting symptom. The physical examination revealed a defect in the region of the deltoid in two patients. Nineteen patients had tears in the muscle belly near the musculotendinous junction, and five had avulsion of the tendon from the acromial origin. Full thickness rotator cuff tears were present in all of the patients, and 22 patients had associated muscle atrophy. Subcutaneous edema and fluid-like signal was present in 15 patients. CONCLUSION: Tears of the deltoid muscle or tendon is an unusual finding, but they can be seen in patients with chronic massive rotator cuff tears. Partial thickness tears tend to involve the undersurface of the deltoid muscle and tendon. Associated findings such as intramuscular cyst or ganglion in the deltoid muscle belly and subcutaneous edema or fluid-like signal overlying the deltoid in a patient with a rotator cuff tear should raise the suspicion of a deltoid tear

OBJECTIVE: Entrapment of the first branch of the lateral plantar nerve is a well-recognized but diagnostically elusive cause of heel pain. The MR finding of selective atrophy of the abductor digiti quinti (ADQ) muscle has been reported as a marker of such entrapment. We performed a prospective study of consecutive patients undergoing foot and ankle MRI to determine the prevalence of ADQ atrophy and to examine the clinical symptoms of patients found to have ADQ atrophy. SUBJECTS AND METHODS: A prospective study of all patients referred for ankle and foot MRI examinations was performed. Six hundred two patients were included in the study: 387 females and 215 males. All images were evaluated for the presence of selective fatty atrophy of the ADQ muscle. The clinical notes on all patients with findings of ADQ atrophy were analyzed for descriptions of symptoms leading to the MR examination, the presence of symptoms that might be related to nerve entrapment, and the influence on clinical management related to the MR finding of ADQ atrophy. RESULTS: Thirty-eight of the 602 patients had selective fatty atrophy of the ADQ, 29 females and nine males. Only one patient had a clinical diagnosis of possible nerve entrapment before MR examination. MRI findings of ADQ atrophy altered clinical management in only one patient. CONCLUSION: Selective fatty atrophy of the ADQ is not a rare finding on MR examination of the foot and ankle, being seen in 6.3% of all studies and in 7.5% of all studies in females. The clinical relevance of selective ADQ atrophy seen on MRI is uncertain

The MRI appearance of 'Little Leaguer's shoulder' has not been previously reported in the radiology literature. Purported etiologies include proximal humeral epiphyseolysis, osteochondrosis of the proximal humeral epiphysis, stress fracture of the proximal humeral epiphyseal plate, and rotational stress fracture of the proximal humeral epiphyseal plate. We describe magnetic resonance imaging findings in four patients and review the literature

This article prospectively determines through magnetic resonance imaging (MRI) the incidence of isolated teres minor atrophy and its gender and age distribution, and documents associated findings related to the rotator cuff, labroligamentous complex, and quadrilateral space. Two hundred seventeen consecutive shoulder MRI examinations performed over a 3-month period were prospectively reviewed and evaluated for isolated teres minor atrophy. Twelve (5.5%) patients had non-compressive isolated teres minor atrophy. Ninety-two percent (n=11) of these patients had rotator cuff or labroligamentous complex tears. No patients had an associated mass within the quadrilateral space. The average patient age was 60 years and 11 of the 12 patients were male. Isolated teres minor atrophy on MRI is most commonly seen in older patients who do not fit the expected clinical presentation of quadrilateral space syndrome. The anatomical relationship of the teres minor nerve to the joint capsule and the frequency of associated shoulder injuries in these patients raises the possibility of an association between humeral decentering and teres minor atrophy. Quadrilateral space syndrome would appear to be a very rare cause of isolated teres minor atrophy