Reverse TSA with augmented baseplate helps treat glenoid wear, bone loss

Surgeons new to reverse TSA should start with cases without glenoid wear before advancing.

Reverse total shoulder arthroplasty with an augmented baseplate has shown promise in patients with advanced glenoid defects, despite a lack in long-term follow-up studies that compare this procedure with other techniques.

Thomas W. (Quin) Throckmorton, MD, who performed reverse total shoulder arthroplasty (TSA) with an augmented baseplate in a live surgery presented at the Current Concepts in Joint Replacement Spring Meeting, told Orthopedics Today that although reverse TSA is beneficial for patients who do not have a functioning rotator cuff, it may not be ideal for patients with glenoid or socket bone loss. In the latter cases, the augmented baseplate is used, he said.

“it may also be helpful to use an augmented baseplate in patients with advanced glenoid loss,” Throckmorton said.

“[The augment] was designed specifically for these sort of shoulder sockets that have bad glenoid bone loss where instead of having to rely on bone graft or accept less than optimal component position, you can make up your deficiency with metal and do your operation in a more standardized fashion,” he said.

Challenges with augmented baseplate

Reverse TSA with an augmented baseplate can be more difficult to perform than standard reverse TSA, according to Throckmorton, who is professor of shoulder and elbow surgery and Residency Program Director at University of Tennessee and Campbell Clinic department of orthopaedic surgery.

Even in mild cases of wear and bone loss, it can be difficult to obtain enough exposure to see the glenoid wear pattern. Furthermore, it can be a challenge to get the instruments into the glenoid bone to machine the socket in cases with severe erosion.

“That is where the system and components we used were helpful that way,” Throckmorton said. “… [The] system was designed to allow you to have an easier access to ream that defect and prepare that difficult-to-reach area of bone which makes the operation —it will never be easy to do — easier to do.”

Throckmorton noted surgeons do not have to worry about changing their usual reverse TSA rehabilitation protocol in patients who received an augmented baseplate and good fixation was achieved.

“Specifically, regarding the augment, one of the things that is nice about it is, if you are making up your deficiencies with metal and you get good fixation in the glenoid, you do not have to change your rehab protocol,” he said.

Start off easy

Throckmorton advises orthopedic surgeons who want to perform reverse TSA with an augmented baseplate to get good exposure and not perform it as their first reverse TSA case.

“If you decide you are going to do a reverse replacement, start off on some of the easier glenoid wear patterns, meaning no glenoid wear and then, as you advance and get more comfortable with that skillset, I think using the reverse to address glenoid deformity … is a next level type of procedure once you are comfortable doing a standard reverse replacement,” he said. – by Casey Tingle

Reference:

Throckmorton TWQ. Reverse TSA with an augmented baseplate: Dealing with glenoid deficiency. Presented at: Current Concepts in Joint Replacement Spring Meeting; May 20-23, 2018; Las Vegas.

For more information:

Thomas W. Quin Throckmorton, MD, can be reached at 1400 S. Germantown Rd., Germantown, TN 38138; email: tthrockmorton@campbellclinic.com.

Disclosure: Throckmorton reports he receives royalties from Zimmer Biomet and Elsevier.