Arthroscopic Posterior Bone Block Stabilization Using a Tricortical Autograft of the Ipsilateral Scapular Spine

Abstract

Posterior bone grafting represents an emerging therapeutic approach for addressing recurrent instability in the posterior shoulder, particularly when coupled with substantial glenoid bone loss. Although not as prevalent as anterior instability, recent years have witnessed the development of numerous open and arthroscopic bony reconstruction methods. A technical gold standard for posterior bone grafting remains undefined, leading to ongoing advancements in bone grafting techniques. In response to past challenges associated with screw fixation, metal-free arthroscopic fixation procedures have been introduced to the realm of bone grafting. These metal-free methods often entail intricate transglenoid drilling, which poses potential surgical complexities and risks to both posterior and anterior soft tissues, as well as neurovascular structures. Therefore, we introduce an arthroscopic approach to posterior bone grafting using PEEK (polyether ether ketone) anchors with interconnected sutures and a scapular spine autograft. This method overcomes previous hurdles by facilitating the restoration of the posterior glenoid bone stock with precise positioning and secure fixation of the tricortical scapular spine bone autograft.

Fig 1

Preoperative radiographic imaging of right shoulder: anteroposterior (A) and axial (B) views. The mis-healed bone fragment (arrow) can be seen at the posterior part of the glenoid. AR, external rotation; R, right.

Fig 2

Lateral view of a 3-dimensional computed tomography image of the right scapula (A) and axial (B) view of the same scan. The mis-healed bone fragment (arrows) can be seen at the posterior part of the glenoid.

Fig 3

Intraoperative patient positioning in lateral decubitus position (right shoulder).

Fig 4

Arthroscopic images of right shoulder with patient in lateral decubitus position. (A) View from posterior. The glenoid surface and a Hill-Sachs impression in the typical position can be seen. (B) View at posterior part of glenoid. A mis-healed fragment is being debrided. (C, D) The defect at the posterior glenoid is measured in preparation of harvesting the graft. (E) The first anchor has already been positioned, the second PEEK anchor is being inserted. (F) The inserted tricortical scapular spine autograft is positioned at the posterior glenoid, and the interconnected sutures are tightened using a wire tensioner.

Fig 5

Three-dimensional computed tomography imaging of right scapula viewed from posterior. The rectangle marks the widest part of the scapular spine, which will be used as a tricortical bone graft.

Fig 6

Postoperative imaging result. (A) Three-dimensional image of right glenoid. The bone block (arrow) can be seen at the posterior part of the glenoid. (B) Axial view of same computed tomography scan with bone block posteriorly (arrow).