Ultrasonic Examination of Biceps and Supraspinatus Tendons in Patients with Chronic Hemodialysis, Referring to Rasoul Akram Hospital in Tehran

Tendinopathy is defined as an overuse injury that is histologically associated with tenocyte proliferation, collagen fiber degradation, and increased non-collagen matrix, fluid accumulation between fibers, capillary proliferation, and calcification. Early diagnosis of tendinopathy is important in order to prevent severe tendon damage or even rupture. Tendinopathies, especially of the shoulder tendons, are common in hemodialysis patients due to loss of tendon elasticity and weakening of the structures, uremic toxins, accumulation of β2-microglubolin and malnutrition.  Tendon rupture is a complication of several disorders including chronic kidney disease and hemodialysis, systemic lupus erythematosus, gout, rheumatoid arthritis, diabetes mellitus, obesity and trauma. Bone changes and soft tissue calcification, spontaneous tendon rupture are some of the factors that can increase tendon thickness in chronic kidney disease patients. The tendons most affected are the quadriceps tendon, the patella tendon, and the Achilles tendon. There has also been a rare case of abdominal muscle tendon in a hemodialysis patient. Secondary hyperparathyroidism is an important factor in tendon rupture. In all patients with elevated Parathyroid hormone (PTH) levels, the risk of spontaneous tendon rupture increases, and there is also an increase in this risk in patients treated with quinolones and steroids. Although magnetic resonance imaging (MRI) and computerized tomography (CT) scan are the main diagnostic methods for assessing joint and surrounding joint pathology worldwide, diagnostic ultrasound has become increasingly used to assess musculoskeletal structure. Ultrasonography (US) is used to evaluate the superficial tendons and ligaments that attach to the joint. The device can detect the presence and features of joint fibrosis, bursae or joint cysts, and can also detect abnormal structures in the joints. Ultrasonography is an effective, inexpensive imaging modality in the evaluation of tendons and is an affordable way to diagnose tendon lesions, especially in dialysis patients. Ultrasonography has been shown to be a successful imaging modality for diagnosis of tendinopathies of shoulder. Early diagnosis of tendinopathies and conservative treatment are essential to prevent severe tendon damage or even rupture. Changes in tissue elasticity can be detected by USE before being detected on B-mode ultrasonography. Elastography methods use changes in soft tissue elasticity as a result of specific pathological or physiological processes. For example, many solid tumors are mechanically different from the surrounding healthy tissue. Also, fibrosis associated with chronic liver disease makes liver tissue harder than normal tissue. In this way, elasticity methods can be used to distinguish involved tissues from natural tissue for diagnostic applications. In recent years, this method has been used to evaluate liver fibrosis or to characterize breast lesions. Ultrasound elasticity test can provide more complete information about tissue hardness along with other measured parameters In some studies, tendon ultrasound showed the presence of calcified tissue and increased tendon thickness, which was positively correlated with parathyroid hormone level and duration of dialysis. This correlation was more significant with the increase of parathyroid hormone. Studies show a significant increase in the thickness of the supraspinatus tendon, biceps tendon, triceps tendon and sub scapular tendon in hemodialysis patients. Therefore, the aim of this study was to evaluate the ultrasound findings of biceps and supraspinatus tendons in chronic hemodialysis patients compared to non-dialysis patients.

  The present study was performed as a case-control study in hemodialysis patients referred to Rasoul Akram Hospital, Tehran. Inclusion criteria included advanced renal failure and regular hemodialysis for at least 6 months three times a week for 4 hours per session. The control group was selected from healthy volunteers.This study was approved with the ethics ID IR.IUMS.FMD.REC.1399.355. First, written consent was obtained from the individuals to enter the study. After obtaining written patient consent, complete patient history and laboratory data (CBC performed on Cell Dyn 1700; serum BUN and creatinine, serum calcium, serum phosphate (PO4), performed with BioLis24I autoanalyzer and stable PTH level Or iPTH was measured on ELISA kits developed by GenWay Biotech.The sonographic evaluation was performed by an experienced rheumatologist using a supersonic device with a linear probe at a frequency of 5.5-7 MHz. The use of ultrasonography due to the high accuracy in the diagnosis of various tendon disorders is either incomplete or complete. The presence of focal or diffuse heterogeneity in tissues with the presence of hypoechogenicity foci, swelling, and calcification in the tendon sheath or soft tissues around the tendon, irregular tendon margins, and fluid accumulation were among the sonographic findings. The data were collected in a checklist designed by the researcher based on the variables and evaluations performed.Data were analyzed using SPSS version 22. First, the variables were tested using the Kolmogorov-Smirnov criterion. Quantitative data were expressed as mean ± standard deviation and qualitative data were expressed as frequency and percentage. Significance level was determined at P <0.05.

During the study period, 60 people (30 dialysis patients as a patient group and 30 healthy individuals as a control group) who met the inclusion criteria were included in the study. There was no statistically significant difference between the studied groups in terms of age, weight and body mass index. The cross-sectional area of the supraspinatus tendon on the right side was significantly higher in patients than in healthy individuals. The mean elastography of the left biceps tendon in patients was significantly higher than healthy individuals. This parameter was not different in the supraspinatus tendon. There was no statistically significant difference between different levels of PTH and tendon thickness and cross sectional area.  In the present study, the elastographic indices of right and left biceps and supraspinatus tendons were not statistically significant in almost all parts of the tendons of patient group in comparison with healthy group. This finding confirms the effect of the other factors on the elasticity of the tendon along with its thickness and cross sectional area. In the study of correlation between elastography of biceps and supraspinatus tendons with age, PTH and tendon thickness, it was found that there is no statistically significant relationship between the mentioned variables and elastography.

In the present study, ultrasound indices of different parts of biceps and supraspinatus tendons of the right and left shoulders of patients and control group were compared with each other. Although it was not statistically significant in most cases, these indicators were generally higher in patients than healthy individuals. Findings of the present study showed that in the patient group, the thickness and cross-sectional area of the right supraspinatus was higher than the control group. Evaluation of ultrasonographic indices did not show a significant change in tendon elasticity in dialysis patients compared to healthy individuals.