Disclosure: I have no financial relationship with any orthopedic implant manufacturer including Stryker the owner of the technology that this post discusses.
You are about to start hearing more about a relatively new technology for treating massive rotator cuff tears. I say “relatively new” because the technology has been available in Europe and a few other regions of world already but not in the United States. That is about to change as this device has recently gained FDA approval. .
Over the past few years I acted as one of the regional principle investigators on a multicenter study to evaluate this technology and was the first surgeon in my region to use the device.
The device called Inspace is a small balloon that the surgeon inflates with saline and in a minimally invasie operation places in the subacromial space (the space between the ball part of your shoulder and your upper shoulder blade). Normally your upper rotator cuff muscles live in this space. But if they are severely torn there is often nothing in this space except remnant of your tendon and bursa. The balloon actually dissolves over a period of about 6 months.
The idea behind the balloon is that it acts as a spacer to cushion the bones from rubbing against one another when you lift your shoulder.
The study that I helped execute compared two equivalent groups of patients that had very large rotator cuff tears. About half received the balloon device and the other half had an arthroscopic “clean up” or what we call a debridement procedure and a partial repair of the rotator cuff. Interestingly, the FDA required that the control group get at least a partial rotator cuff repair. This is interesting and becomes important as I will discuss soon.
When rotator cuff tears are very large and irreparable, surgeons will often elect to either debride or smooth the remaining tissue or do a partial repair if possible. This study mandated that the surgeons do at least a partial repair in the control group.
The results have not yet been published but some data was presented at the recent American Academy of Orthopaedics (AAOS) meeting which showed that the balloon treatment was “non inferior” or no worse than debridement and partial rotator cuff repair. Additionally the balloon patients improved more quickly and clinically on average had slightly better range of motion at 2 year follow up.
This sounds promising but questions remain.
If you have a massive rotator cuff tear should you get the balloon? Questions remain…
The answer is not so clear cut. For one, it’s unclear if the balloon procedure is actually better than debridement or not. I found it odd that the FDA required the investigators to perform at least a partial repair in all control patients. Often when tears are large enough there is very little tissue to repair and one wonders if we were repairing tissue that in many cases would have been better off leaving alone. I will be interested to look at the data more deeply when it gets published in a peer review journal. How much of the rotator cuff was repaired in the control patients? We know that NONE of the roatotor cuff tendon was repaired in the balloon group. How do we know that the repair itself did not have some negative effect on patients’ motion long term?
Secondly we see that the balloon patients improved more quickly. However that would be expected as surgeons typically protect patients who have had rotator cuff repairs longer in a sling before they let them advance their therapy. In other words, the balloon patients likely improved more quickly because they were allowed to rehabilitate faster than the rotator cuff repair group. This begs the question: if the control group did not get a repair and just got a debridement, would they have improved at the same rate at the balloon group? From this study design we cannot know the answer to that question.
Lastly, one wonders if the partial repair had something to do with the worse range of motion seen at 2 years in the repair group. Did the partial repair make these patients stiffer? Again, would these control patients have been better served if they simply underwent debridement and no repair? We cannot know from these data.
While the study was designed as a strict randomized controlled trial, it was not designed in such a way to completely isolate the effect of the balloon on outcome. If it were, we would have had to do a partial repair in both groups and then insert the balloon in only one group or do no repair in both groups and insert the balloon in only one group.
Instead the partial repair was only performed in the non balloon (control) group. This leaves us to wonder which of the outcome effects stem from the balloon and which stem from the partial repair portion of the procedure.
In summary the balloon treatment and the arthroscopic debridement procedure are roughly equivalent. It is an intriguing technology and it’s still an open ended question as to whether any slight benefits seen in the balloon group should be attributed to virtues of the new technology or are simply the downside of having done too much by performing a partial repair. The device is on a limited rollout currently and the full peer reviewed published study is not yet in circulation. We await this publication for a more in depth analysis. Time will tell how much value this technology will bring to patients with massive rotator cuff tears
If you have a large or massive rotator cuff tear and are interested in knowing about options for treatment feel free to contact our office at 716-204-3200 to schedule a consultation. Dr. DiPaola is available for telemedicine as well as in person consultations.