Story of subacromial balloon : is there a proof of science?

Background: Irreparable rotator cuff tears present a significant clinical challenge due to superior humeral head migration and the loss of coronal plane force couples. While various reconstructive and prosthetic options exist, the subacromial biodegradable spacer has emerged as a less invasive alternative designed to restore glenohumeral kinematics.

Objective: This article reviews the development, biomechanical principles, clinical efficacy, and patient selection criteria for the implantation of a poly-L-lactide-co-ε-caprolactone (PLCL) subacromial spacer.

Key Points: Biomechanical studies indicate that the spacer translates the humeral head inferiorly, reduces subacromial pressure, and facilitates deltoid-mediated abduction. Clinical data from five-year follow-ups demonstrate significant improvements in Constant scores, particularly regarding pain relief and activities of daily living, with results comparable to more invasive procedures. Although the implant degrades within 12 months, functional benefits often persist, potentially due to improved postoperative rehabilitation facilitated by early pain reduction. However, some studies report inconsistent outcomes, with satisfaction rates as low as 40% in specific cohorts. Complications are infrequent, occurring in approximately 3.4% of cases, and include spacer migration or infection. Success appears highly dependent on the preservation of transverse plane force couples, specifically the integrity of the subscapularis and teres minor.

Conclusion: Subacromial spacer implantation is a safe, technically straightforward procedure for managing irreparable rotator cuff tears. It is most effective in patients with preserved active range of motion whose primary symptom is pain, serving as a viable bridge or alternative to more complex reconstructive surgeries.