Assessing the Therapeutic Efficacy of Shoulder Pacemaker Technology versus Traditional Physiotherapeutic Interventions for Acute-on-Chronic Rotator

Abstract

Acute-on-chronic rotator cuff pathology (AoC-RCP) represents a clinically distinct subset of shoulder disorders characterized by acute symptom exacerbation superimposed upon pre-existing degenerative tendinopathy, yet evidence-based rehabilitation protocols specifically targeting this phenotype remain scarce. This prospective comparative study evaluated the efficacy of a novel Shoulder Pacemaker™ (SPM) device, a wearable bioelectronic stimulator delivering closed-loop, kinematically synchronized suprascapular nerve stimulation, versus conventional physiotherapy in 40 patients with AoC-RCP. Participants were allocated to either SPM-enhanced rehabilitation (n = 20) or standardized deltoid-focused physiotherapy (n = 20) at a single tertiary physiotherapy center. Primary outcomes included Visual Analog Scale (VAS) pain scores, the American Shoulder and Elbow Surgeons (ASES) index, and the Constant-Murley scores, assessed at baseline and 24 months. Treatment failure was defined as surgical referral or patient dissatisfaction. At 2-year follow-up, the SPM group demonstrated significantly superior outcomes: 95% treatment success (19/20 patients) versus 50% in conventional physiotherapy (10/20 patients; p = .002), with mean VAS 1.7 versus 3.6 (p = .003), ASES 70 versus 51 (p = .001), and Constant-Murley 62 versus 46 (p = .001). These findings suggest that bioelectronic augmentation of rehabilitation may substantially improve long-term outcomes in AoC-RCP, though randomized controlled trials are warranted to confirm efficacy and establish mechanisms of action.