Avoiding the Common Pitfalls in Anatomic TSA
In a presentation from ICJR’s webinar series, ICJR Insights: Advanced Concepts® in Shoulder Surgery, J. Michael Wiater, MD, explored the top 10 top issues (plus 1 bonus issue) that can mean the difference between a successful and an unsuccessful anatomic total shoulder arthroplasty (TSA).
Patient positioning and draping. This is where the surgeon sets the stage for success. The patient should be positioned so that the shoulder can be easily extended and adducted, facilitating joint dislocation and delivering the humeral head out of the surgical wound. The surgeon should also keep an eye on the draping process to ensure that the surgical field isn’t inadvertently contaminated.
Subscapularis management. Dr. Wiater prefers a lesser tuberosity osteotomy because the healing can be followed radiographically, but other surgeons might prefer a tenotomy or a peel. All 3 are good options.
Humeral exposure. For most shoulders, especially tight shoulders, Dr. Wiater will subperiosteally elevate the anterior half of the deltoid insertion with a large Cobb elevator. This takes pressure off the anterior head of the deltoid, which allows for better exposure and easier dislocation of the humerus and prevents the deltoid from being torn or damaged by retractors.
Glenoid exposure. Because Dr. Wiater’s mantra is “less is more,” he uses only 2 retractors in most cases when obtaining glenoid exposure, an anterior glenoid retractor and a posterior Darrach retractor. Another point: The inferior capsule release is the key release to exposing the glenoid. If it is not released, it will act as a checkrein to posterior displacement of the humerus and prevent access to the glenoid.
Soft tissue balancing. Anatomic TSA is as much a soft tissue procedure as it is a bony procedure, Dr. Wiater said. The goal is to ensure that the humeral head is centered in the glenoid, which may not be easy to do: Patients with osteoarthritis often have tight anterior soft tissue, sometimes with retroversion of the glenoid, a lax posterior capsule, and posterior humeral head subluxation. The surgeon needs to be prepared to correct these issues to facilitate centering the humeral head.
Rotator cuff insufficiency. An intact and functioning rotator cuff is mandatory for anatomic TSA. If there is any question about the status of the rotator cuff, the surgeon should order magnetic resonance imaging preoperatively and then inspect the rotator cuff intraoperatively to ensure that anatomic TSA is the appropriate operation.
Glenoid retroversion. Patients with Walch type B or C glenoids may not have enough bone stock left to accommodate standard anatomic TSA implants. A CT scan can help the surgeon determine if the deformity can be corrected through eccentric reaming or an augmented glenoid component or if a reverse TSA might be a better option.
Implant size and position. An anatomic TSA should, as the name suggests, provide an anatomic reconstruction. Getting the implant size and position right the first time is essential: An improperly sized or malpositioned implant can only be corrected with revision surgery.
Anatomic TSA in young, active patients. These patients can be challenging, especially if they’re muscular, and may require different techniques and implants for success – for example, use of a bone-preserving stemless humeral component and a porous metal glenoid component with a vitamin E polyethylene. They will also need to be counseled about activity modification to help improve implant longevity.
Conversion to reverse TSA. Not every anatomic TSA goes as planned, so the surgeon needs to be prepared to convert to a reverse TSA intraoperatively. Dr. Wiater ensures that he has reverse TSA implants and instruments available and he obtains consent for a reverse procedure with every anatomic TSA patient.
Bonus: Glenoid vault fractures. This is an uncommon but disastrous intraoperative complication that typically occurs in older women with severely osteopenic bone. To avoid fracturing the glenoid vault, be sure to remove the osteophytes before reaming and then use a light touch with the reamer to start, gradually adding more pressure.
These are just a few of the tips, tricks, and techniques from Dr. Wiater. Click here to watch his presentation and find out more of what he had to say about avoiding the pitfalls of anatomic TSA.
J. Michael Wiater, MD, is professor of orthopedic surgery at Oakland University William Beaumont School of Medicine, Rochester, Michigan. He is also vice chairman, chief of shoulder and elbow surgery, and program director for the fellowship in shoulder and elbow surgery in the Department of Orthopedic Surgery at Beaumont Health, Royal Oak, Michigan.
Disclosures: Dr. Wiater has disclosed that he has stock or stock options in and is a paid consultant and paid presenter or speaker for Catalyst OrthoScience LLC; that he receives royalties from DePuy Synthes; that he receives royalties from and has stock or stock options in Ignite Orthopedics; that he receives royalties from Smith & Nephew; and that he is a paid presenter or speaker for Zimmer Biomet.