Arthroscopic Distal Clavicular Autograft for Congruent Glenoid Reconstruction

Abstract

Arthroscopic distal clavicular autograft (DCA) is effective in shoulder instability with glenoid bone loss. The original technique uses an osteochondral autograft, fixed with screws or suture anchors. We developed a modified procedure called "congruent arc DCA" characterized by (1) use of drilling guides to optimize graft positioning and make the all-arthroscopic procedure safer and reproducible; (2) rotation of the DCA of 90° to reach a congruent arc with its undersurface; (3) fixation of the graft with cortical buttons to simplify its intra-articular passage, avoid hardware problems, and facilitate possible revision surgery; and (4) intraoperative use of a suture tensioner to achieve satisfactory compression of the graft and increase its consolidation.

Fig 1

Arthroscopic glenoid reconstruction with a congruent arc distal clavicle autograft (DCA). (A) After arthroscopic subperiosteal dissection, osteotomy and drilling, the DCA is transferred through the rotator interval onto the glenoid neck. (B) The portion of DCA is rotated of 90° to provide a “congruent arc construct” with its undersurface and fixed with 2 cortical buttons, after tensioning the sutures.

Fig 2

Visualization of the glenohumeral joint through open rotator interval, viewed from the lateral portal. Intraoperative image of the right shoulder. The arthroscope is positioned in the lateral portal, in order to have a fully glenohumeral joint view through the rotator interval. (G, glenoid surface; HH, humeral head, LHB, long head of the biceps, SS, supraspinatus tendon, SSC, subscapularis tendon.)

Fig 3

Glenoid preparation and drilling. (A) After glenoid neck abrasion, a specific hooked glenoid guide (Smith & Nephew) is introduced through the posterior portal, between the glenoid (G) and the humeral head (HH). (B) Arthroscopic view of the right shoulder showing the glenoid neck. The arthroscope is moved to the anterolateral portal. The guide, introduced through the posterior portal, must be flush to the glenoid surface and located at 4-o’clock position. A cannulated K-wire (2.8 mm) is drilled through the guide, across the glenoid. (C) The glenoid drilling is guided and remains intra-articular, eliminating neurological complications or further work close to the brachial plexus.

Fig 4

Distal clavicle exposure and osteotomy. Intraoperative images of the right distal clavicle. (A) Lateral view of the distal clavicle (DC) after subperiosteal dissection. The superior capsule (SC) and the deltoid-trapezial fascia (DTF) are preserved to prevent any lateral instability of the acromioclavicular joint. (B) View of the distal clavicle from the anterolateral portal with a spinal needle, to visualize the osteotomy line; usually, a 10-mm bone graft is sufficient to reconstruct up to 30% glenoid bone loss. (C) A high-speed oscillating saw is used to perform a slightly oblique osteotomy of the distal clavicle under arthroscopy.

Fig 5

Distal clavicle autograft drilling. (A) Arthroscopic anterolateral view of the osteotomy of the distal clavicle completed. (B and C) A specific 3-arms guide (Smith and Nephew) introduced from the anteromedial portal is used to clamp the DCA and drill bit across the bone block.

Fig 6

Distal clavicle autograft transfer and fixation. (A) Traction is placed on the suture at the back of the shoulder, in order to pass the bone block through the rotator interval and bring it on the anterior glenoid rim. (B) The posterior button is slide along the suture, exiting posteriorly and a sliding-locking knot (Nice knot) is performed. (C) A tensioning device from posterior portal is used to rigidify sutures and put compression on the bone graft. (D) The underside of the clavicle bone block is facing laterally so as to use the natural concavity od the graft on the articular side, thus creating a congruent construct.

Fig 7

Clinical illustration in a 30-year-old man with 2 previous failed stabilization procedures (failed arthroscopic Bankart and failed open Latarjet). (A) Anteroposterior radiographs showing a recurrence of anterior dislocation with bended screws and coracoid bone block lysis. (B) CT scan with sagittal view showing significant (25%) loss of anteroinferior glenoid rim. (C) Arthroscopic view showing screws removal. (D) Final arthroscopic view showing DCA flush with the glenoid surface (G) and no impingement with humeral head (HH). (E) Postoperative radiograph showing glenoid reconstruction after screws removal and cortical button fixation of the arthroscopically DCA. (F-G) Postoperative axial 2-dimensional CT scan view showing perfect positioning of the bone graft (flush to the glenoid surface) and use of the concave underside of the clavicle to recreate the articulation with a “congruent construct.” (H) Patient seen at 1-year follow-up with normal aspect of the shoulder, without any migration of the distal clavicle, donor-site pain or instability. (CT, computed tomography; DCA, distal clavicle autograft.)