Chronic shoulder instability secondary to glenoid dysplasia

Clinical History

A 25-year-old was referred to our radiology department complaining of left shoulder pain after repetitive shoulder dislocation secondary to hand support fall. He had also experienced a left acromioclavicular dislocation practicing sports 6 months before.

Imaging Findings

Shoulder arthrography was performed under fluoroscopic guidance using anterior approach and with gadolinium and iodine dilution injection, immediately the patient underwent CT arthrography (CTA) and MRI arthrography (MRA).
CTA and MRA showed a severe glenoid dysplasia with reduced volume of its posterior aspect and compensatory cartilage and labral hypertrophy. Buford complex with thickening of the middle glenohumeral ligament and hypoplasia of the anterosuperior labrum was also present. The anteroinferior labrum and the anterior band of the glenohumeral ligament were hypertrophic. Posterior labrum had a large tear extending from seven to twelve hours following the clockwise classification. The labral tear continued to the superior labrum, SLAP type 2 associated. A paralabral cyst was demonstrated with its origin depending on the type II SLAP lesion. A small chondral lesion was also shown.

Discussion

Glenoid dysplasia is a rare disorder defined as bone deficiency of the posteroinferior glenoid rim, with secondary hypertrophy of the adjacent cartilage [1]. It is more frequent than previously thought. Glenoid dysplasia has no sex predilection, it is frequently bilateral (60%), and its diagnosis can be made within a wide range of ages [2]. The pathogenesis appears to be a failure of ossification of the inferior cartilaginous glenoid and scapular neck. There are several associations described in the literature including multiple epiphyseal dysplasia, deficiencies of Vitamin C and D, muscular dystrophies, Erb’s palsy, haemophiliac arthropathy and neonatal septic arthritis. Familiar cases have also been reported [3]. Patients become symptomatic in their second or third decade of life, usually related to an increase in their daily or sport activity. There is a second peak described at the fifth or sixth decade [1]. Symptoms are pain, decreased range of movements and instability. Early osteoarthritis can be present [3]. Radiographic findings have been described on plain radiography, but CT and MRI have become the best techniques to study this abnormality, especially after intraarticular contrast injection [4]. Radiological findings are hypoplasia of the scapular neck and hypoplasia of the posterior glenoid with compensatory glenoid rim and labral hyperplasia. Hooking of the distal clavicle, enlargement of the coracoid process and acromion, and flattening of the humeral head can be present.
Glenoid dysplasia can be classified into mild, moderate and severe types. Especially moderate and severe types are frequently associated with posterior labral tears and posterior instability of the glenohumeral joint [1, 5]. We present the case of a 25-year-old man with left shoulder pain and instability. Severe glenoid dysplasia was demonstrated in CT arthrography and MR arthrography. In our patient extended posterior labral tear was present together with a SLAP type II lesion as described in the literature. In our case, there was hypoplasia of the scapular neck but no coracoid or humeral head alterations were seen.
Treatment is controversial, with most authors advocating conservative measures.

Differential Diagnosis List

Final Diagnosis

Severe glenoid dysplasia associated with posterior labral tear.

URL:	https://www.eurorad.org/case/11803
DOI:	10.1594/EURORAD/CASE.11803
ISSN:	1563-4086