Overview
John M. Tokish, M.D., an orthopedic surgeon at Mayo Clinic's campus in Arizona, initiates diagnostic arthroscopy to assess pathology and then obtains preoperative imaging. Dr. Tokish prepares the glenoid surface for graft placement, creating a flush surface to receive the graft. He prefers a tibial allograft and soaks the graft with platelet-rich plasma. He places a Latarjet guide until the flange sits flush on the glenoid. He then places Kirschner wires and overdrills to create tunnels for fixation. Through these tunnels, he places an arthroscopic router that can prepare the surface of the bone. To offset the patient's bone loss, he places 8 to 12 millimeters of graft arthroscopically and can visualize an exact match to the glenoid surface. The graft is secured without metal implants and with greatly decreased risk of neurovascular complications.
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MODERATOR: This is a description of the arthroscopic technique for distal tibial allograft bone augmentation with suture anchor fixation for anterior shoulder instability. Here are relevant disclosures. A diagnostic arthroscopy is performed to thoroughly assess the patient's pathology. Preoperative imaging is correlated with intraoperative visualization to focus on the area of bone loss.
Capsular and aggressive labral liberation is performed. And the anterior glenoid surface is prepared for graft placement by debridement down to viable bone with an emphasis on creating a flush surface to receive the graph. A single suture is placed through the anterior labrum and retrieved percutaneously. And this allows lateral retraction that is utilized to facilitate graft delivery. After creating adequate posterior capsular access, while viewing from the superior anterior portal, the latarjet guide is placed from the posterior portal until the flange sits flush on the glenoid, and the guide is in direct bony contact posteriorly.
Kirschner wires are then placed through the posterior guide until they are visualized to be at the anterior margin of the glenoid. These wires should be placed parallel to each other, parallel to the glenoid surface, and with a 6mm offset. After the guide is removed, the wires are over drilled using a 3.5 millimeter cannulated drill. Following the top-hat sleeves from the FlipCutter drills are placed over the cannulated drills, which are then removed, leaving the FlipCutter top-hats in place. The inferior FlipCutter is then placed into the top hat and advanced across the glenoid from the posterior until anterior until it's visualized.
The FlipCutter is then gently spun and gently retracted until a perfect rounded flesh cut is obtained in the inferior half of the glenoid. Then this process is repeated through the superior drill hole. This should result in a near perfect planing cut of the anterior gleno without any significant step off along with superior and inferior access.
The FlipCutters are then removed and replaced with FiberStick Arthrex devices such that there's a passing stage from posterior anterior through each of the drill holes. Distal Tibia allograft is the graft of choice for the authors. And the tibial allograft is cut to the appropriate size. Typically, 8 millimeters of graft is sufficient to restore approximately 30% of glenoid bone loss.
Using the same latarjet offset guide that was used on the glenoid, two drill holes are created oriented parallel to the long axis of the graft. Two 2.6 millimeter FiberTak are then loaded retrograde through the graft holes such that the tails of the suture are passed from anterior to posterior through the graft outside the shoulder. The FiberTak loops through which a trailing stitch is placed, remain on the anterior aspect of the graft. The prepared graft is then soaked in PRP.
First, the mid-glenoid portal is replaced with the larger 16 millimeter cannula. And the two previously placed passing stitches that were placed through the glenoid are retrieved through the mid-glenoid portal. With the camera in the anterior superior portal, the passing sutures are pulled from the back. This allows the glenoid graft to be delivered through the large mid-glenoid portal.
Posteriorly, the inferior FiberTak passing sutures pass through the loop end of the superior FiberTak and delivered through the superior anchor. Likewise, the superior passing suture is placed through the loop end of the inferior FiberTak loop and delivered through the inferior anchor. This creates a double mattress self-locking mechanism.
As the graft is delivered, the passing sutures are progressively and alternately tensioned until the graft is compressed to the desired position on the glenoid. There should be a near anatomic restoration of alignment between the cartilage surfaces of the graft and the glenoid. Once the graft is positioned appropriately, attention is turned to the labrum. The sutures previously placed at the anterior loops are now passed through the native anterior labrum, which repairs the native labrum to the anatomic anterior aspect of the graft.
Remaining PRP is then placed into the joint. Patients are placed in a sling post-operatively in neutral rotation for six weeks with pendulum movements allowed immediately and gradual return to passive motion at three weeks. Full return to activities permitted at six months. Thank you.