Background: Double row arthroscopic rotator cuff repair has been the gold-standard for rotator cuff repair in the last few years. The supraspinatus is the most susceptible muscle to rupture in this context. The aim of this study was to evaluate patients submitted to a double row arthroscopic repair of the rotator cuff with isokinetic tests, surface electromyography and Constant-Murley Score, and correlate these data with their clinical evolution four months after surgery. 

 

Methods: Six patients with isolated and unilateral ruptures of the supraspinatus muscle, confirmed by MRI, were submitted to isokinetic dynamometry, surface electromyography and Constant-Murley functional Score. Injured and uninjured shoulder results were collected immediately before and four months after the surgery.  

 

Findings: Our results show improvements in isokinetic, strength and functional parameters. Isokinetic results correlate well with functional and clinical scores and add value to the follow-up process. For the angular velocity of 90º/s in post-op, the angle at Peak Torque for the injured and uninjured limb was approximately the same (~42º). Electromyographic measurements provided valuable insight over the electrical activation of muscles of the shoulder girdle. After surgery, electromyographic measurements showed a lower normalized activation pattern for the injured and uninjured muscles, suggesting an increased efficiency in post-operative muscle function. 

 

Interpretation: The performed surgery was effective. The selected four-month time frame is an important landmark to evaluate patients´ recovery, since our data showed that most variables collected on the injured limb tend to evolve towards the values of the uninjured limb.  

 

Keywords: supraspinatus, double row repair, rotator cuff, isokinetic, surface electromyography.