Arthroscopic Bone Block Cerclage Suture Fixation of Fresh Distal Tibial Allograft for Anterior Glenoid Reconstruction

Assessment of Primary Stability and Micromotion of Different Fixation Techniques for Scapular Spine Bone Blocks for the Reconstruction of Critical Bone Loss of the Anterior Glenoid-A Biomechanical Study

Anteroinferior shoulder dislocations require surgical intervention when related to critical glenoid bone loss. Scapular spine bone blocks have emerged as a promising alternative to traditional bone augmentation techniques. However, limited data exist on their biomechanical stability when using different suture-based fixation techniques. This study aimed to evaluate primary stability and micromotion after glenoid augmentation using a scapular spine bone block. A total of 31 fresh-frozen human shoulder specimens underwent bone block augmentation. The specimens were randomized into three groups: double-screw fixation (DSF), single-suture bone block cerclage (SSBBC), and double-suture bone block cerclage (DSBBC). Biomechanical testing was conducted using cyclic loading (5000 cycles at 1 Hz) and micromotion was analyzed using an optical 3D measurement system. Statistical analysis showed that medial irreversible displacement was significantly greater in the SSBBC group compared to DSF (p = 0.0386), and no significant differences were found in anterior or inferior irreversible displacements. A significant difference was noted in posterior reversible displacement (p = 0.0035), while no differences were found in inferior or medial reversible displacements. Between DSF and DSBBC, no significant differences were found in irreversible or reversible displacements in any direction. DSBBC provided stability comparable to DSF while offering a viable metal-free alternative. In contrast, SSBBC displayed inferior biomechanical properties, raising concerns about its clinical reliability.

Sutures, Screws, Buttons, and Anchors: A Review of Current Bone Graft Fixation Devices for Glenoid Bone Loss in the Unstable Shoulder

PURPOSE OF REVIEW

Anterior shoulder instability is associated with concomitant injury to several stabilizing structures of the shoulder, including glenoid bone loss. While instability is most common in young athletes and patients with predisposing conditions of hyperlaxity, recurrent shoulder instability can occur throughout various age ranges and may lead to longer term effects including pain and shoulder arthritis. Glenoid bone loss exceeding certain thresholds is generally treated by glenoid reconstruction via bone block augmentation to adequately stabilize the glenohumeral joint. These procedures increase the width of the articular surface on which the humeral head can translate before dislocation and, based on the procedure performed, provide a sling effect via the conjoined tendon, and increase tension to support the anterior capsule. The purpose of this review is to summarize the available literature regarding bone block fixation techniques.

RECENT DEVELOPMENTS

Various fixation techniques have been utilized to secure bone block transfers. Though screw fixation has traditionally been used for bone block fixation, suture buttons, suture anchors, and all-suture techniques have been utilized in attempts to avoid complications associated with the use of screws. Biomechanical studies report variable force-resistance, displacement, and mode of failure when comparing screw to suture button-based fixation of glenoid bone blocks. Clinical and radiographic studies have shown these novel suture-based techniques to be comparable, and in some cases advantageous, to traditional screw fixation techniques. While screw fixation has long been the standard of care in glenoid bone block procedures, it is associated with high complication rates, leading surgeons to endeavor toward new fixation techniques. In available biomechanical studies, screw fixation has consistently demonstrated high maximal load-to-failure and displacement with cyclic loading. Studies have reported similar clinical and radiographic outcomes in both screw and suture-based fixation methods, with evidence of reduced bone resorption with suture fixation. While suture button fixation is associated with a higher rate of recurrent instability, overall complication rates are low. Future research should address biomechanical shortcomings of suture-based fixation techniques and continue to assess long-term follow-up of patients treated with each fixation method.