Revision Anterior Glenoid Reconstruction With Distal Tibia Allograft Combined With Open Capsular Shift

Abstract

Background:

Managing patients with recurrent anterior shoulder instability and glenoid bony deficiency remains a challenge. Multiple graft options, including iliac crest, distal clavicle, coracoid, and distal tibia allograft have been used. There is a growing body of evidence that supports distal tibia allograft for glenoid restoration in patients with shoulder instability due to its ability to restore the articular surface as well as the glenoid depth and curvature.

Indications:

Surgical indications for anterior glenoid reconstruction with distal tibia allograft combined with open capsular shift include patients with recurrent shoulder instability and glenoid bone loss.

Technique Description:

A deltopectoral interval is utilized and the subscapularis is split in lines with its fibers. The subscapularis and capsule are split together in a horizontal fashion and tagged together. Any prior hardware is then removed utilizing appropriate removal sets, a burr, and a broken screw set if necessary. The anterior glenoid is then prepared and the defect is measured. Bone marrow aspirate is then harvested from the proximal humerus using a vortex needle. The distal tibia allograft is then cut to size and prepared utilizing pulsed lavage, pressurized sterile carbon dioxide, and the bone marrow aspirate. The allograft is then fixed with solid stainless steel 3.5-mm cortical screws with washers. The medial, glenoid based capsular repair it completed by placing 1.8-mm knotless FiberTak anchor at the bottom of the distal tibia allograft. A free needle is utilized to place a horizontal mattress stitch from the anchor to the inferior capsule, which is then loaded onto a shuttling suture, to repair it to the anterior inferior glenoid. A knotless anchor is then placed right off the chondral margin of the humeral head, and this is used to repair both the capsule and subscapularis in the correct position by passing through both inferior and superior leaflets. This is then loaded onto the knotless anchor and reduced, which shifts the subscapularis and capsule laterally. The remainder of the subscapularis split is then closed. Patients are then placed in a sling with an abduction pillow with no shoulder range of motion for 6 weeks. They can then progress their therapy with a goal of returning to sport at 6 months.

Results:

Several large systemic reviews have shown that return to sport rates after anterior glenoid reconstruction range between 80% and 90%, with returning to the same level of play in the 70% range.

Discussion:

Anterior glenoid reconstruction utilizing distal tibia allograft combined with an open capsular shift is a durable surgical option for patients presenting with shoulder instability and glenoid bone loss.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

In this video, we will demonstrate our technique for revision anterior glenoid reconstruction using distal tibia allograft combined with an open capsular shift for a patient who has anterior glenoid bone deficiency and a known hypermobility disorder. Managing patients with recurrent anterior shoulder instability and glenoid bony deficiency remains a challenge. ⁴ Multiple studies have been published that cover various graft options, including iliac crest, distal clavicle, coracoid, and distal tibia allograft. ² In recent years, there is a growing body of evidence that supports the use of distal tibia allograft as a viable option for patients with shoulder instability due to its ability to restore the articular surface, glenoid depth, and curvature.^1,3,5,6

Our patient is an 18-year-old female with Ehlers-Danlos syndrome, who has a 5-year history of recurrent shoulder instability. She has had four previous surgical procedures, including a labral repair, revision repair with remplissage, hamstring labral reconstruction, and Latarjet with capsulorrhaphy. Despite this, she continues to have daily and constant subluxations. She also has persistent anterior snapping with internal and external rotation, and after ultrasound evaluation of the shoulder, it was clear that this was due to her subscapularis snapping back and forth over her previous Latarjet screws. On physical exam, the humeral head sits in an anterior and inferior subluxated position and she states that it has been in that position for roughly 6 months. She also has mild scapular winging with moderate neuromuscular dysfunction. Her range of motion is quite limited. She does have 5/5 strength and is able to fire all muscles. With gentle forward elevation and a mild posterior force, the humeral head can be reduced onto the glenoid, but this causes her substantial pain when it is relocated as she is not used to the shoulder being in this position. The humeral head sits anteriorly subluxated, but can easily be reduced with gentle forward flexion and a posterior force; however, this causes quite a bit of pain and discomfort for the patient because she is not used to that position. When the arm is released, it subluxates again.

Radiographs demonstrate previous Latarjet with partial resorption of the upper portion of the bone block, and the humeral head is sitting in an anterior and inferior subluxated position. This is confirmed by 2D and 3D computed tomography (CT) scanning, and this demonstrates approximately 25% anterior glenoid bone loss and an anterior subluxated humeral head. As a first step, the patient underwent preoperative physical and occupational therapy, focusing on neuromuscular retraining. The surgical plan afterward was for screw removal, revision glenoid reconstruction with the distal tibia allograft, and capsular repair with shifting. The surgical equipment is listed here. A repeat CT scan was performed just before surgery and you can see the improvement of the glenohumeral joint position after 3 months of neuromuscular retraining compared to her initial presenting images.

The patient is positioned in the beach chair position using a mechanical arm holder. Her previous incision from her prior surgeries performed elsewhere was utilized. Electrocautery was used to dissect through skin. The subcutaneous tissues were then re-prepped with dilute hydrogen peroxide to minimize the risk for Cutibacterium acnes. A deltopectoral interval was utilized to identify the subscapularis deep and a self-retaining retractor was placed. The subscapularis was identified and then it was split in line with its fibers separating the upper two thirds from the inferior one third. Because we're performing a capsular shift, the subscapularis and the capsule are split together in a horizontal fashion. The capsule and subscapularis are then tagged together at both the upper portion and the lower portion. An anterior glenoid retractor is placed deep to the subscapularis and anterior to the glenoid neck, and a Gelpi retractor is used to retract the subscapularis superiorly and inferiorly. This exposes the previous hardware. The screws are then removed, but in this case, the lower screw had a broken screw head. This was removed along with the washer. The superior screw is removed in a standard fashion. A Fukuda retractor was placed to protect the humeral head. A burr is used to remove the bone around the inferior broken screw. The screw is removed with the clamp from the broken screw removal set.

The anterior glenoid is then prepared using a rongeur and a burr. Great care is taken to remove the least amount of bone necessary to get down to a bleeding smooth surface. The dimensions of the defect are then measured to allow for appropriate sizing of our distal tibia allograft. Bone marrow aspirate is harvested from the proximal humerus by impacting and then twisting in a vortex needle. Approximately 20 ccs of aspirate is utilized. On the back table, the measurements are transferred to the distal tibia allograft, which is then cut to size. Once the graft is freed, it is then prepared. This is first accomplished using pulsed lavage to try to remove as many of the marrow elements as possible. After this, the graft is blasted with pressurized sterile CO₂ to remove additional allograft marrow elements. The patient's bone marrow aspirate is then loaded onto the graft and allowed to soak into the interstices of the graft on all surfaces. Afterward, the graft is placed in a small cup and allowed to soak in the bone marrow aspirate for approximately 10 min before final implantation. A small portion of the uncut allograft is morselized and then packed into small defects on the anterior glenoid from her previous screws and anchors from her prior surgery.

The allograft is then held into place and then secured with a single pin. A 3.5-mm drill is used to drill through the allograft and a 2.5-mm drill is used to drill the remainder of the glenoid. The depth is measured and then a solid stainless steel 3.5-mm cortical screw is placed with a washer. The pin is removed and the process is repeated for the superior screw. A 1.8-mm knotless FiberTak anchor is then placed into the glenoid at the bottom of the distal tibia allograft. The Fukuda retractors are removed to provide access to the inferior capsule. The Gelpi retractor is then pulled out of the capsule so that it only retracts the subscapularis, leaving the capsule free. A free needle is used to pass the repair stitch from the anchor through the inferior capsule in a large horizontal mattress fashion. This is then loaded onto the shuttling suture and used to repair the capsule down to the anterior inferior glenoid to reduce inferior capsular volume.

The process is then repeated in the humeral head, where another knotless anchor is placed in the humeral head just off the chondral margin. A free needle is used to pass the repair stitch through both the capsule and the subscapularis in a medialized position. This is passed through the inferior leaflet and in the superior leaflet as well. This is then loaded onto the knotless anchor and reduced. This will shift the subscapularis and capsule laterally, and it also overlaps the structures in a pants-over-vest fashion. This can substantially reduce the anterior capsular volume and tighten the subscapularis. The remainder of the subscapularis split is then closed in a pants-over-vest fashion as well to finalize the capsular shift and tightening. The incision is closed in layers and is then covered with Steri-Strips and a waterproof dressing. Here's a comparison of the pre- and post-operative CT scans demonstrating the anterior glenoid reconstruction.

When performing surgeries on patients with neuromuscular dysfunction, preoperative neuromuscular retraining can be incredibly helpful to help the patient become more comfortable with the shoulder in the reduced position in the glenoid. When performing a concomitant capsular shift with the distal tibia allograft, it is helpful to split the capsule horizontally rather than vertically. Also important is to always have a broken screw removal set available. In order to optimize graft biology, we recommend utilizing pulsed lavage, pressurized CO₂, and the patient's bone marrow aspirate. Finally, we recommend using rigid fixation in these patients that are high risk for early post-operative instability.

After surgery, patients are placed in a sling with an abduction pillow with no shoulder range in motion during the first 6 weeks. From week 6 to 12, passive range of motion is initiated and advanced strengthening begins at 3 months, and at this time, we consider neuromuscular retraining if needed. Return-to-sport progressions are initiated around 5 months, with a goal of returning to sports at 6 months. In order to return to athletic activities, the patients must have full motion, full strength, no apprehension, no pain, appropriate radiographic healing, and have successfully completed a return to sport progression.

It has been studied relatively extensively and multiple systematic reviews have shown that return to sport rates after anterior glenoid reconstruction generally range in the 80% to 90% range, but that returning to the same level of play is slightly less typically in the 70% range.