Technetium-99m-MDP patterns in patients with painful shoulder lesions

There is no consensus on the optimum mode of imaging in patients with painful shoulder lesions. There is a particular paucity of scintigraphic data. As a result, the strengths and weaknesses of scintigraphy cannot be adequately compared to other imaging techniques used in shoulder imaging. This study evaluated whether specific patterns of scintigraphic abnormality could be detected in patients with painful shoulders seen in rheumatological practice using 99mTc-methylene diphosphonate (MDP).

Scintigraphic abnormalities were recorded in consecutive patients presenting to a rheumatology clinic with unilateral shoulder pain. Patients were subdivided according to patterns of clinical abnormality consistent with a working diagnosis of a lesion located in the subacromial region, adhesive capsulitis (frozen shoulder) or a lesion likely to be located in the glenohumeral joint. Patterns of radiopharmaceutical distribution in different regions of the shoulder were evaluated in the light of clinical data and the results of shoulder radiographs.

Technetium-99m-MDP scans were abnormal in 19 of 24 (79%) patients, and radiographs were abnormal in 8 of 24 (33%) patients. Distinct patterns of 99mTc-MDP image abnormality were identified: an increase in 99mTc-MDP uptake in the coracoid, acromion and medial humeral head on anterior planar images, together with an absence of posterior planar image abnormality, frequently occurred in association with a working diagnosis of a lesion located in the subacromial region. Posterior planar 99mTc-MDP image abnormalities always occurred in patients with clinical features consistent with a diagnosis of adhesive capsulitis. There was an 85% agreement between two observers' scores when 99mTc-MDP distribution in specific shoulder regions was graded.

Distinct patterns of 99mTc-MDP distribution may be associated with clinically-distinct patterns of abnormality in patients with painful shoulder lesions. Further studies to elucidate a role for 99mTc-MDP scintigraphy in this patient group are warranted.