Study finds glenoid faceplate fixation during Bankart repair fails to stabilize the shoulder

SAN FRANCISCO — Use of a “bumper” of capsulolabral tissue and glenoid faceplate fixation during Bankart repair do not aid in creating a more stable shoulder, according to a presentation here.

Scott P. Steinmann, MD, shared his group’s findings at the 2011 Annual Meeting of the Arthroscopy Association of North America.

“This is a simple study trying to answer a question we often ask ourselves: Does it make a difference to create a bumper?” he said. “If we put the anchor a little bit on the articular surface is that helpful or does it even really make a difference?”

Repair at different locations

Scott P. Steinmann

The investigators studied nine fresh-frozen cadaveric shoulders of individuals who had a mean age of 75 years by using a testing machine with a six-degree-of-freedom load cell. The group applied a 50N axial force to the humerus, translating the humeral head in the anterior direction and then measuring peak transitional force at the end-range (defined in the study as having 60° of abduction relative to the scapula and maximum external rotation) and mid-range (defined in the study as having 60° of abduction and neutral rotation) positions either with the intact capsule, with a Bankart lesion, or after Bankart repair both with and without a bumper.

The investigators performed Bankart repairs at five different locations — the glenoid rim, 2mm inside from the glenoid rim, 5mm inside from the glenoid surface, 2mm medial on the scapular neck from the glenoid rim and 5mm medial on the scapular neck from the glenoid rim.

The bumper, Steinmann added, was created through the gathering of the capsule and formation of a thickened tissue mass.

Bumper offers no impact

The investigators found peak transitional force to be “significantly decreased” following the creation of a Bankart lesion and restored to “almost the intact condition” upon Bankart repair at both arm positions.

Steinmann noted, however, that the bumper made no significant differences in forces following Bankart repair. “At the end range, there was no significant difference with or without a bumper … at the mid-range, it was very similar,” he said.

Forces decreased significantly after the 2- and 5-mm scapular neck fixations when compared to those found following glenoid rim fixation and 2mm glenoid surface fixation at both arm positions, Steinmann added. However, he cautioned that forces significantly increased at the end-range position and decreased at the mid-range position after 5mm glenoid surface fixation.

“The bumper did not contribute in this study to stability, but we do not think it is a bad idea. It does not hurt, but we did not show in this study that it actually made a difference,” Steinmann concluded. “Meanwhile, placing on anchors onto the surface of the glenoid is not necessary and certainly, when you go 5 mm in, it actually may start to hurt you both with range of motion and by pulling on the anchors.”

Reference:
Steinmann SP, et al. Anchor placement on the glenoid faceplate does not improve stability with Bankart repair. Paper SS-02. Presented at the 2011 Annual Meeting of the Arthroscopy Association of North America. April 14-16. San Francisco.
Disclosure: Steinmann receives royalties from DePuy, is a paid consultant for Arthrex, DePuy and Wright Medical Technology, Inc. He receives research or institutional support from Wright Medical Technology, Inc. and receives publisher royalties from the Journal of Hand Surgery — American, the Yearbook of Hand Surgery, and the Journal of Shoulder and Elbow Surgery.

The authors tried to demonstrate whether a bumper is really an important result for us when we are done doing our stabilizations. Although this is visually pleasing, if anyone were to go back to their shoulders a year later, we often make the same observation that the labrum is no longer present and the capsule is smooth with the edge of the glenoid.

I'm not sure whether or not anchor placement on the articular surface, as Steinmann has pointed out, has become an important result. This may have other factors. This may have to do with cyclic loading, allowing for a suture to saw through the bone. If we get close to the edge, unfortunately, we do not have that ring of articular cartilage and perhaps what turns out to be a well-placed anchor on a corner can migrate. Placing anchors on the glenoid neck is fraught with not creating the translation limits we were trying to achieve.

– Jeffrey S. Abrams, MD
Moderator

Disclosure: Abrams receives royalties from CONMED Linvatec and Arthrocare; is on the speakers' bureau of Mitek, is a paid consultant for CONMED Linvatec, Arthrocare, Wright Medical Technology, Inc. and Core Essence Orthopaedics; holds stock or stock options in Arthrocare, Cayenne Medical, Kfx Medical and Ingen Medical; receives publisher royalties from Springer; is a member of the Board of Directors for the Arthroscopy Association of North America and is Vice President of American Shoulder and Elbow Surgeons.

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