A Systematic Review of Screw and Suture Button Glenoid Augmentation Constructs

Arthroscopic Bone Block Stabilization for Anterior Shoulder Instability with Subcritical Glenohumeral Bone Loss

PURPOSE OF REVIEW

The management options for anterior shoulder instability with minimal bone loss or with critical bone loss are well established. However, there is less clear evidence to guide management for patients with subcritical bone loss, the spectrum of pathology where soft tissue repair alone is prone to higher rates of failures. In this range of bone loss, likely around 13.5% to 20%, the goal of surgery is to restore function and stability while limiting morbidity. As with many procedures in the shoulder, this decision should be tailored to patient anatomy, functional goals, and risk factors. This article provides a review of our current understanding of subcritical bone loss and treatment strategies as well as innovations in management.

RECENT FINDINGS

While surgeons have largely understood that restoration of anatomy is important to optimize outcomes after stabilization surgery, there is increasing evidence that reconstructing bony anatomy and addressing both osseous and soft tissue structures yields better results than either alone. Even in the setting of subcritical bone loss, there is likely a benefit to combined osseous augmentation with soft tissue management. Additionally, there is new evidence to support management of even on-track humeral lesions when the distance to dislocation is sufficiently small, particularly for athletes. Surgeons must balance bony and soft tissue restoration to achieve optimal outcomes for anterior instability with subcritical bone loss. There are still significant limitations in the literature and several emerging techniques for management will require further study to prove their long-term efficacy. Beyond surgery, there should be a focus on a collaborative treatment strategy with the surgeon, patient, and therapists to achieve high-level function and minimize recurrence.

Arthroscopic Technique for Headless Compression Screw Fixation of Large Bony Bankart Fractures in Anterior Shoulder Instability

A bony Bankart fracture is a common injury pattern in anterior shoulder instability. The fracture fragment size varies and the larger the fragment the more likely recurrent instability will occur. When a large bony Bankart fracture is present, surgical fixation is preferred. Both open and arthroscopic approaches exist with multiple fixation techniques including anterior-to-posterior screw fixation, suture anchor bridge fixation, and suture button fixation. Arthroscopic screw fixation is difficult, as the angle necessary to be parallel to the glenoid surface requires a far medial start point and places the nerve at risk. The use of a variable-pitch, headless compression screw placed from posterior to anterior avoids these risks. We describe an arthroscopic technique for glenoid fixation using a posterior-to-anterior, cannulated, variable-pitch headless compression screw for the treatment of an anterior BBF.

Editorial Commentary: Suture-Button Fixation May Have Advantages Over Screw Fixation for Glenoid Bone Grafting Procedures for Shoulder Instability

Orthopaedic suture buttons have been increasingly used in a variety of procedures, such as syndesmosis stabilization, coracoclavicular ligament repair, anterior cruciate ligament graft fixation, and Lisfranc injury treatment. In many instances, suture-button fixation constructs have shown equivalent, if not superior, outcomes to screw fixation. More recently, suture buttons have been suggested for osseous fixation of the coracoid during the Latarjet procedure, as well as other anterior (or posterior) bone block reconstruction of the glenoid using distal tibial allograft, tricortical iliac crest, or distal clavicle in cases of complex shoulder instability. Suture buttons offer several unique advantages, including the ability to tension and retension graft fixation, smaller driller paths with bone preservation, less osteolysis, lower risk of hardware removal, and greater ease of hardware revision and/or secondary surgery. However, certain disadvantages also exist, such as higher implant costs, less time-zero implant rigidity, technical difficulty, and, potentially, less mediolateral stability of the bone graft. Time will tell if these suture-button constructs will supplant traditional screw fixation for the Latarjet procedure in terms of clinical and cost-effectiveness.

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.

Editorial Commentary: Suture Button Fixation for the Latarjet Procedure Is Superior to Screw Fixation

An increasing body of evidence suggests that suture button fixation is comparable with screw fixation in Latarjet and potentially associated with reduced graft resorption. Suture button fixation may facilitate performing the Latarjet procedure, particularly when done in an arthroscopic manner. The use of suture button fixation technique theoretically facilitates improved positioning of the graft on the glenoid, as it frees the surgeon from the potential of the soft-tissue envelope to impact positioning of the graft, which can occur with screw-based guides. The bone graft can be shuttled into an optimal position and then tensioned with relative ease in comparison with screw-based techniques. Suture button fixation results in lower complication rates compared with screw fixation; almost one third of the screw fixation complications are hardware-related, and screw fixation results in a high rate of hardware removal. Moreover, the arthroscopic Latarjet suture button literature is published by experienced surgeons. Arthroscopic Latarjet has a significant learning curve, reducing the translatability of studies that report superior findings with any one technique. The generalizability of results reminds us that evidence-based medicine should be practiced through the lens of not only patient preferences, but also through an honest appraisal of a surgeon's own ability.