Extracorporeal shockwave therapy (ESWT) is widely used to treat soft tissue disorders, but evidence for its application after rotator cuff (RC) repair is lacking.

To investigate the effect of ESWT on short-term functional and structural outcomes after RC repair.

Thirty-eight individuals were randomly assigned to the ESWT group (n = 19) or control group (n = 19) 3 months after RC repair. Both groups underwent 5 weeks of advanced rehabilitation and participants in the ESWT group additionally received 2000 pulses of shockwave therapy every week for 5 weeks. The primary outcome was pain measured on a visual analog scale (VAS). Secondary outcomes were range of motion (ROM), Constant score, University of California Los Angeles score (UCLA), American Shoulder and Elbow Surgeons form (ASES), and Fudan University shoulder score (FUSS). Changes in signal/noise quotient (SNQ), muscle atrophy and fatty infiltration were analyzed from MRI. All participants underwent clinical and MRI examinations 3 months (baseline) and 6 months (follow-up) post repair.

A total of 32 participants completed all assessments. Pain and function improved in both groups. At 6 months post repair, pain intensity was lower and ASES scores higher in the ESWT than in the control group (all p-values < 0.01). SNQ near the suture anchor site decreased significantly from baseline to follow-up in the ESWT group (p = 0.008) and was significantly lower than that in the control group (p = 0.036). Muscle atrophy and the fatty infiltration index did not differ between groups.

ESWT and exercise more effectively reduced early shoulder pain than rehabilitation alone and accelerated proximal supraspinatus tendon healing at the suture anchor site after RC repair. However, ESWT may not be more effective than advanced rehabilitation in terms of functional outcomes at the short-term follow-up.