Subacromial Injections of Low- or High-Molecular-Weight Hyaluronate Versus Physical Therapy for Shoulder Tendinopathy: A Randomized Triple-Blind Controlled Trial.

OBJECTIVE

Shoulder tendinopathy is a prevalent and debilitating problem. We compared the effects of subacromial high- or low-molecular-weight hyaluronate injection with physical therapy (PT) in shoulder tendinopathy.

DESIGN

A triple-blinded randomized controlled trial.

SETTING

We conducted the trial in an outpatient clinic at a teaching hospital.

PARTICIPANTS

In total, 79 patients with shoulder tendinopathy were randomly allocated to high- (n = 27) or low-molecular-weight (n = 28) hyaluronate or PT (n = 24) groups.

INTERVENTIONS: We administered a 20-mg injection of high- or low-molecular-weight hyaluronate. For PT, we prescribed 10 sessions of physiotherapy and exercise.

OUTCOME MEASURES: The primary outcome was shoulder pain and the secondary outcomes included Disability of the Arm Shoulder and Hand score, shoulder range of movement and QoL. We measured the outcomes at baseline, 1, and 3 months of treatment, and assessed shoulder pain at the sixth month postintervention.

RESULTS

The interventions were all clinically beneficial in the management of tendinopathy for high- (n = 25) and low-molecular-weight (n = 24) hyaluronate and PT (n = 19) groups (all P < 0.05). However, between-group analyses indicated that hyaluronate preparations were more effective in controlling pain, decreasing disability, increasing range of motion, and improving the quality of life (all P < 0.05). The pain and subjective feeling of rigidity at the injection area ( P = 0.012) were less prominent for low-molecular-weight hyaluronate.

CONCLUSION

High- or low-molecular-weight hyaluronate is more effective than PT in the treatment of shoulder tendinopathy. The clinical benefits of hyaluronate last for at least 3 months, and the pain alleviation sustains partially for 6 months. Shoulder injection of low-molecular-weight hyaluronate is more tolerable to the patient than high-molecular-weight hyaluronate.