The InSpace subacromial spacer balloon is as good as partial repair of the rotator cuff, according to the results of a prospective, randomized, multicenter trial presented at the American Academy of Orthopaedic Surgeons (AAOS) 2021 Annual Meeting. The device, which has been used outside the United States, was approved by the US Food and Drug Administration (FDA) in July 2021.
The balloon adds a new option for shoulder surgeons in addressing massive rotator cuff tears. The goal of surgery is to repair the rotator cuff in the hopes that the tendons heal back onto the bone. But this is not always possible if the tear is significantly old, retracted, or atrophied.
If the topmost rotator cuff tendon, the supraspinatus, does not heal, the humeral head can begin to rise up, which can lead to dysfunction of the shoulder and, in worst-case scenarios, arthritis.
A more complex surgery involving an allograft patch to reconstruct the superior capsule of the shoulder has been used in recent years, but it is technically demanding, and enthusiasm for this approach appears to be waning.
The subacromial balloon purportedly provides a technically easier option to address this challenging problem.
The new data come from a trial involving 184 patients who were at least 40 years of age and who had experienced symptomatic, full-thickness, massive rotator cuff tears. Nonsurgical management had failed.
The researchers found that outcomes with the balloon spacer were noninferior in comparison with partial rotator cuff repair at 24 months’ follow-up.
According to Joseph A. Abboud, MD, professor of shoulder and elbow surgery at Thomas Jefferson University, Philadelphia, Pennsylvania, the study was part of a rigorous FDA device study. In an interview with Medscape Medical News, he explained that outcomes, which were assessed over 2 years, “demonstrated noninferiority to partial repair and in several instances superiority.”
In addtion, the balloon procedure was as safe as partial repair, and operative times were shorter.
Abboud expressed surprise at how many patients quickly volunteered for the study of a device that had not received FDA approval. “I think it speaks to the fact that many patients hear that massive tears have poor prognoses and new approaches such as the balloon…may have some advantages,” he said.
Abboud told Medscape, “The balloon is an option for a subset of patients who are nonarthritic with good but not great overhead motion who are looking for an intervention to help them improve their quality of life with minimal operative intervention, immobilization, and associated morbidity.”
Dr Albert Dunn
Albert S. M. Dunn, DO, an orthopedic sports medicine surgeon at Precision Orthopaedic Specialties, in Chardon, Ohio, expressed interest in using the implant in an interview with Medscape. “I like the idea of the spacer, especially for a patient with poor healing potential, such as smokers. Ultimately, I don’t believe anything beats well-healed functional muscle tendon unit to bone, but in situations where that’s not possible, this seems like a great alternative.”
Dunn, who was not involved in the study, had a specific subset of patients in mind: “I would use this for massive cuff tear patients with poor-quality tissue and poor healing potential who are still dependent on unrestricted use of their arm, [for example] the construction worker with a two-pack-a-day habit whose shoulder has hurt for the last 3 years and is just showing up to have it evaluated now.”
For Dunn, the balloon may provide an option in cases in which social factors, such as smoking, limit the ability of the rotator cuff to heal. “The major advantage compared to partial repair is nothing really has to heal, so it does help to eliminate that patient factor that we don’t have control over,” he said.
According to Abboud, the technology also may change the surgical algorithm: “This is a technology that really makes us question our approach to massive, irreparable tears, and in some instances simplifies it.” Yet he cautions that it is not a panacea: “Figuring out the best candidates for each treatment will at times still be challenging.”
Abboud is a consultant for Stryker but receives no royalties related to the Inspace device. Dunn reported no relevant financial relationships.