The long-term effects of hyaluronic acid on hemiplegic shoulder pain and injury in stroke patients: A randomized controlled study

Background: Hemiplegic shoulder pain (HSP) is one common complication after stroke. The interferes with the functionality of the affected shoulder in patients with stroke during rehabilitation. Hyaluronic acid (HA) could have positive effects on pain relief and shoulder motion in stroke patients with hemiplegic shoulders. We investigated long-term benefits of HA injection in stroke patients with HSP and rotator cuff injury. Methods: A randomized, double-blinded controlled trial was conducted in one medical center. The stroke patients with HSP and rotator cuff injury were randomized and allocated to the control (n = 9) and experimental (n = 18) groups. The control and the experimental groups received ultrasound-guided subacromial 0.9% sodium chloride and HA injections, respectively. All injections were performed once per week for 3 weeks. The associated upper extremity functional assessments, shoulder pain scale, and sonography findings on affected shoulders were measured before interventions and at the 4th and 12th week after local injections. Results: The visual analog scale (VAS) scores of HSP were significantly reduced in the control and experimental groups at the 4th week following intervention. Additionally, the VAS score at the 12th week was also significantly reduced in the experimental group. Significant differences were found in the hyperemia occurrence in the subscapularis tendon at the 12th week after intervention (P=.018) and in the severity of hyperemia in the long head of the biceps tendon (P=.042) and the subscapularis tendon after intervention (P=.014). Conclusion: Subacromial HA injections might provide longer HSP reduction and decrease in hyperemia reactions at the long head of biceps tendon and subscapularis tendon in stroke patients with HSP and tendon injury. Abbreviations: FMA-UE = Fugl-Meyer assessment for the upper extremity, HA= hyaluronic acid, HSP = hemiplegic shoulder pain, VAS = visual analog scale.