Chronic non-traumatic shoulder pain: evaluation with ultrasonography and conventional mr imaging
Authors: Elaassar M M N , Emadeldin A , Zidan D Z , Sakr H M , Abdelazim H 
Published: May 2020

Abstract

Background
Shoulder pain is a common and disabling complaint. It is responsible for approximately 16 % of all musculoskeletal disorders1 Shoulder pain is defined as chronic when it has been present for longer than six months, regardless of whether the patient has previously sought treatment2. The most common causes of chronic shoulder pain are reported to be rotator cuff disorders, acromioclavicular joint (ACJ) disease and glenohumeral joint (GHJ) disorders3

Aim of the Work
The aim of this study is to evaluate the role of both ultrasonography and conventional MRI imaging in diagnosing various causes of chronic shoulder pain not caused by trauma.

Patients and Methods
101 patients were evaluated for chronic shoulder pain ranging in age from 20 to 70-years-old. They were referred to the radiology department (Ultrasound unit and MRI unit) at Ain Shams University hospitals during the period between September 2016 and June 2018, from orthopaedic, rheumatology and physical medicine departments. Once a patient satisfied the inclusion and exclusion criteria for this study, an elaborate history was taken from all the patients which was followed by a thorough clinical evaluation, in which duration of symptoms, affected side, dominant hand, range of movement was checked. Patients were subjected to sonographic evaluation of the shoulder joint followed by MRI of the affected shoulder with mean interval between sonography and MRI about 10 days (range, 5-15 days).

Results
Total of 101 patients with chronic shoulder joint pain were enrolled in our study. 58 % of the patients were in the age group of 41-55 years with mean age of 48 years. Majority (42 %) of patients had chronic shoulder pain over 6-9 months. Complaints mainly resided in the form of tenderness (65 %) and night pain (25 %). Females constituted most of the patients around 68% of the cases. Majority (72%) patients in our study had right hand dominance. 57 % of the sampled patients gave positive history of heavy use of the affected shoulder. 78 % of patients demonstrated acromion morphological changes that had a direct impact on the rotator cuff findings. Amongst the rotator cuff tendons, Supraspinatus tendon was the most common tendon to be involved in our study in both USG and MRI. USG detected 92 patients and MRI detected 96 patients with supraspinatus tendon pathologies which included tendinosis, tears and calcifications and other non-rotator-cuff related findings. Total of 53 were diagnosed as rotator cuff-tear, followed by subacromial-subdeltoid bursitis (n = 32), supraspinatus impingement (n = 14), calcific tendinitis (n = 7) respectively. Supraspinatus tendinopathy was the most common diagnoses (n = 51) followed by Partial thickness tear of supraspinatus (n = 19) then full thickness of supraspinatus (n = 17). USG showed a sensitivity of 52.6% and specificity of 87.8 %, NPV of 88.9 % and PPV of 50 % with 78.8 % MRI agreement for partial thickness tears. USG showed 88 % sensitive, 97% specific, had 97 % PPV, 100% NPV, and was 96 % accurate in diagnosing complete tendon tear. MRI had a higher efficacy for both full thickness as well as partial thickness tears, whereas USG had a higher efficacy for full thickness tears only. Our study shows MRI to be a highly sensitive as well as specific technique for differentiation among different shoulder pathologies.