A Head-to-Head Evaluation of Subacromial Balloon Spacer vs. Partial Repair for Massive Rotator Cuff Tears

    Although various treatment options are available, successfully managing patients with massive rotator cuff tears remains a challenge.

    One option that has generated considerable interest among orthopaedic surgeons is implantation of a biodegradable subacromial balloon spacer that has the potential to recenter the humeral head within the glenoid. This device (InSpace, Stryker; Kalamazoo, Michigan) has just received clearance from the US Food and Drug Administration.

    Over the past decade, more than 29,000 subacromial balloon spacers have been implanted in patients outside the US, with positive results. “However, few studies have been completed that compare the balloon spacer implant with other surgical procedures over a longer period of time with a significant number of patients,” said Nikhil Verma, MD, from Rush University Medical Center in Chicago, Illinois.

    Dr. Verma, the principal investigator, presented the findings of a prospective, randomized, multi-center trial with the subacromial balloon spacer at the American Orthopedic Society of Sports Medicine-Arthroscopy Association of North America Combined 2021 Annual Meeting.

    The researchers found that use of the device during surgery for massive rotator cuff tears produced outcomes similar to those of partial rotator cuff repair at 24-month follow-up, with potential for early improvement.

    This non-inferiority, prospective, single-blinded, multi-center, randomized, controlled, pivotal study included patients age 40 years or older who had symptomatic, full-thickness, massive rotator cuff tears (tears of 5 cm or more, involving 2 or more tendons) that had failed non-operative management. A total of 184 patients from 20 institutions were randomized into the clinical study, 93 in the balloon spacer arm and 91 in the partial repair arm.

    The safety and effectiveness of the subacromial balloon spacer were evaluated by patient reported and physician-assessed outcomes, including American Shoulder and Elbow Society (ASES) score, Western Ontario Rotator Cuff Index (WORC), and Constant Shoulder Outcome Score (CS). Patients were evaluated at POD10; week 6; and months 3, 6, 12, and 24. 

    Patients in the balloon spacer group demonstrated similar results to patients in the partial repair group for ASES substantial clinical benefit (SCB) threshold improvement. The ASES SCB has previously been defined as a change of 17.5 points. At 24-month follow-up, 82% (76/93) of patients in the balloon spacer group and 79% (72/91) in the partial repair group had reached the SCB change from baseline threshold.

    Significant improvement over time relative to baseline was observed in ASES and WORC scores in both groups. Early improvements were noted in the balloon spacer group for WORC, CS, and range of motion outcomes. Mean procedure duration was approximately 44 minutes for the balloon spacer group and 71 minutes for the partial repair group.

    Subsequent secondary surgeries to the treated shoulder occurred in 6 patients (3 each for the balloon spacer and partial repair), with 2 patients in each group requiring reverse shoulder arthroplasty and 1 patient in each group undergoing shoulder arthroscopy. One additional patient in the balloon spacer group required a subsequent reverse shoulder arthroplasty due to fracture non-union following a fall.