Ultrasound changes after rotator cuff repair: is supraspinatus tendon thickness related to pain?
Tham ER, Briggs L, Murrell GA. J Shoulder Elbow Surg. 2013 Jan 23. pii: S1058-2746(12)00523-X. doi: 10.1016/j.jse.2012.10.047. [Epub ahead of print]
Rotator cuff tears are common injuries in overhead athletes causing a significant increase in pain and decrease in function. Cuff tears commonly require surgical repair; however, the results after surgery are mixed with both repair failures and successful repairs not having significant pain relief. These poor outcomes may be related to anatomic adaptations at the shoulder following rotator cuff repair but it is unclear what these adaptations may be and whether they are related to pain. Therefore, Tham et al. evaluated whether there are changes in rotator cuff tendon thickness, subacromial bursa thickness, tendon attachments, tendon vascularity, and posterior glenohumeral capsule thickness after a rotator cuff repair and if tendon thickness was related to pain. Among 57 patients that underwent a surgical repair, the authors found 16 patients that had intact supraspinatus tendons bilaterally. They used diagnostic ultrasound to measure several anatomic features on the involved (surgical) and uninvolved shoulder as an internal healthy control. Participants also completed a questionnaire about pain. Ultrasound measures and the pain questionnaire were completed at 1, 6, 12, and 24 weeks post-surgery. The authors found that bursa thickness, vascularity, and posterior capsule thickness decreased from 1 to 24 weeks. The anatomic footprint (tendon attachment) increased from 1 to 24 weeks. Compared to the contralateral control, bursal and posterior capsule thickness were significantly different at 1 week but that difference was not present by 6 weeks. The participants’ shoulder pain decreased overtime; however, there was no correlation between tendon thickness and shoulder pain.
This is an interesting study that examines the anatomic changes that occur following successful rotator cuff repairs. Several structures seem to go through a remolding stage as the tendon heals and the joint returns to homeostasis. The most apparent adaptations that are occurring are decreases in bursal thickness and vascularity. Following surgical repair there is an active tendon repair process occurring that requires a large amount of signaling proteins and growth factors. These biologic factors are delivered from the bursa and increased blood flow. However, as the stages of healing progress the presence of these biologic factors are decreased. This is in agreement with the current studies results. The time points are very clinically meaningful, demonstrating that the first 6 weeks are important for successful healing (bursal thickness). In addition the authors observed a thick posterior capsule thickness early after surgery, which decreased overtime. The authors were surprised by this finding and it suggests that the entire joint experiences adaptions following surgery. Specifically, this measure of posterior capsule thickness may relate to post-operative shoulder stiffness. In fact this was recently found to be true in healthy overhead athletes. Therefore, posterior capsule thickness may be a very useful measurement to predict or identify patients that are suffering from shoulder stiffness. As clinicians we can optimize the treatment of patients with thick posterior capsules and improve their short- and long-term outcomes. In the future it would be interesting to examine the patients that had failed rotator cuff repairs to identify if any of these adaptations were the cause. Do you use diagnostic ultrasound throughout rehab to track structural changes? Do you think there are anatomic adaptations that can help us strategize patient care?
Written by: Stephen Thomas
Reviewed by: Jeffrey Driban
Related Post:Tham ER, Briggs L, & Murrell GA (2013). Ultrasound changes after rotator cuff repair: is supraspinatus tendon thickness related to pain? Journal of Shoulder and Elbow Surgery PMID: 23352550