Ultrasonographic determination of changes and degree of damage in asymptomatic shoulder joint periarticular structures in RA patients and comparison with healthy controls.

It was designed as a prospective single-blind case-controlled clinical study. Written informed consent was obtained from all study participants who met the study criteria and agreed to participate in the study.

30 RA patients between the ages of 18-75 who had been diagnosed with RA for at least 12 months according to the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria and had no complaint of shoulder pain; Patients will be randomly assigned to the patient group according to the order in which they arrive at the outpatient clinic, regardless of age, gender and disease activation. Exclusion criteria for the study include patients with clinically suspected shoulder pathology, a history of previous shoulder surgery, a history of direct trauma to the shoulder, a history of infectious arthritis, other connective tissue diseases, serious and chronic somatic or psychiatric diseases, any previous fracture in the upper extremities, and patients with limited joint movement.

Healthy volunteers who do not have any complaints or problems regarding the shoulder area will be included in the control group, consisting of a total of 30 participants with similar age, gender and non-RA comorbidities as the RA patient group. Exclusion criteria are the same as the exclusion criteria for the RA patient group.

Demographic data of RA and healthy volunteers such as age, height, weight, body mass index (BMI), gender, marital status, education level, occupation and dominant hand will be recorded. Joint examinations will be performed by an experienced rheumatologist to evaluate the patients' sensitive and swollen joints. The medical history of the patients with RA, including the duration of the disease and the medications they use, and the shoulder joint examination of all participants will be performed by the same physical medicine and rehabilitation specialist doctor blinded to the patient and healthy volunteers. During the examination, joint range of motion (ROM) which include active and passive flexion, extension, abduction, internal and external rotation movements of the shoulder and special tests (Hawkins, Neer, Jobe, Patte, Yergason, Gerber) will be used.

US evaluation of both shoulders of all participants will be performed by the same experienced doctor with more than 5 years of experience in this field, using the MyLab60 brand US machine with a 7-12 MHz superficial probe. The physician performing the evaluation will be blinded to the participants. In order to evaluate intra-rater reliability, measurements will be made twice on 5 patients, 1 day apart.

Ultrasound Shoulder Pathology Rating Scale (USPRS) will be used in the evaluation. USPRS consists of 3 static and 2 dynamic examinations. Static tests; It consists of evaluation of greater tuberculum cortical surface irregularity, biceps and supraspinatus tendinopathy. Dynamic tests are performed to evaluate supraspinatus and subscapularis compression by having the patient abduct and externally rotate, respectively. The USPRS score varies between 0-20 points, while 0 points indicate no pathology, 20 points indicate the highest level of pathology in all variables. While the participants are in a sitting position; A total of 5 variables, including bicipital tendinopathy, supraspinatus tendinopathy, greater tuberculum cortical surface irregularity, supraspinatus dynamic and subscapularis dynamic examination, are evaluated and scored according to the level of pathology; The total USPRS score is obtained by adding the scores of all variables.

Another parameter evaluated by ultrasonography in this study is the acromiohumeral distance (AHM) measurement. One of the most common causes of shoulder pain is subacromial impingement syndrome, and AHM measurement with musculoskeletal ultrasound (MSK-US) is important as it is also a two-dimensional linear measurement of the subacromial area and a marker of rotator cuff diseases. In AH distance measurement with MSK-US, two measurements will be made with all participants in a neutral resting position and their hands at the top of the circle with the elbow angle of 110 °. In both positions, the probe will be placed longitudinally at the lateral point of the acromion determined by palpation, the distance determined between the acromion and the humeral head will be displayed and measured.

Inclusion Criteria:

• RA patients between the ages of 18-75 who has been diagnosed with RA for at least 12 months according to the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria and has no complaint of shoulder pain.

Exclusion Criteria:

• Patients with clinically suspected shoulder pathology, a history of previous shoulder surgery, a history of direct trauma to the shoulder, a history of infectious arthritis, other connective tissue diseases, serious and chronic somatic or psychiatric diseases, any fracture in the upper extremities, and patients with limited joint movement.

RA patients and healthy volunteers(have close demographic data with RA patients)