Anatomic osteochondral glenoid reconstruction for recurrent glenohumeral instability with glenoid deficiency using a distal tibia allograft

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.

Current Evidence and Techniques for Arthroscopic Bone Augmentation

The indications for bone block augmentation of the glenoid following recurrent anterior shoulder instability are expanding. Arthroscopic anatomic glenoid reconstruction (AAGR) is an evolving technique with similar clinical results to the Latarjet procedure and other open bone block procedures. Multiple types of bone grafts and fixation techniques have been described, with varying results on bony integration, resorption, articular congruity, and recurrence rates. This review focuses on biomechanics, patient workup, indications, current evidence, and the authors' preferred surgical technique for AAGR.

The Kouvalchouk procedure vs. distal tibial allograft for treatment of posterior shoulder instability: the deltoid "hammock" effect exists

BACKGROUND

In 1993, Kouvalchouk described an acromial bone block with a pedicled deltoid flap for the treatment of posterior shoulder instability. This procedure provides a "double blocking" effect in that the acromial autograft restores posterior glenoid bone loss and the deltoid flap functions as a muscular "hammock" resembling the sling effect of the conjoint in the Latarjet procedure. The primary aim of this study was to compare the Kouvalchouk procedure to distal tibial allograft (DTA) reconstruction for the management of posterior shoulder instability with associated bone loss, while the secondary aim was to evaluate the deltoid hammock effect.

METHODS

Ten upper extremity cadavers were evaluated using a validated shoulder testing apparatus in 0° and 60° of glenohumeral abduction in the scapular plane. Testing was first performed on the normal shoulder state and was followed by the creation of a 20% posterior glenoid defect. Subsequently, the Kouvalchouk and DTA procedures were conducted. Forces of 0N, 5N, 10N, and 15N were applied to the posterior deltoid tendinous insertion on the Kouvalchouk graft along the physiological muscle line-of-action to evaluate the 'hammock" effect of this procedure. Testing was additionally performed on the Kouvalchouk bone graft with the deltoid muscle sectioned from its bony attachment. For all test states, a posteriorly directed force was applied to the humeral head perpendicular to the direction of the glenoid bone defect, with the associated translation quantified using an optical tracking system. The outcome variable was posterior translation of the humeral head at an applied force magnitude of 30N.

RESULTS

The Kouvalchouk procedure with the loaded deltoid flap (10N: P = .039 and 15N: P < .001) was significantly better at reducing posterior humeral head translation than the DTA. Overall, increased glenohumeral stability was observed with increased force applied to the posterior deltoid flap in the Kouvalchouk procedure. The 15 N Kouvalchouk was most effective at preventing posterior humeral translation, and the difference was statistically significant compared with the 20% glenoid defect (P = .003), detached Kouvalchouk (P < .001), and 0N Kouvalchouk (P < .001). The 15 N Kouvalchouk procedure restored posterior shoulder joint stability to near normal levels, such that it was not significantly different from the intact state (P = .203).

CONCLUSIONS

The Kouvalchouk procedure with load applied to the deltoid was found to be biomechanically superior to the DTA for the management of posterior shoulder instability with associated bone loss. Additionally, the results confirmed the presence and effectiveness of the deltoid "hammock" effect.

Management of bone loss in anterior shoulder instability

Bone defects are frequently observed in anterior shoulder instability. Over the last decade, knowledge of the association of bone loss with increased failure rates of soft-tissue repair has shifted the surgical management of chronic shoulder instability. On the glenoid side, there is no controversy about the critical glenoid bone loss being 20%. However, poor outcomes have been described even with a subcritical glenoid bone defect as low as 13.5%. On the humeral side, the Hill-Sachs lesion should be evaluated concomitantly with the glenoid defect as the two sides of the same bipolar lesion which interact in the instability process, as described by the glenoid track concept. We advocate adding remplissage to every Bankart repair in patients with a Hill-Sachs lesion, regardless of the glenoid bone loss. When critical or subcritical glenoid bone loss occurs in active patients (> 15%) or bipolar off-track lesions, we should consider anterior glenoid bone reconstructions. The techniques have evolved significantly over the last two decades, moving from open procedures to arthroscopic, and from screw fixation to metal-free fixation. The new arthroscopic techniques of glenoid bone reconstruction procedures allow precise positioning of the graft, identification, and treatment of concomitant injuries with low morbidity and faster recovery. Given the problems associated with bone resorption and metal hardware protrusion, the new metal-free techniques for Latarjet or free bone block procedures seem a good solution to avoid these complications, although no long-term data are yet available.

Open Bone Augmentation Solutions for the Failed Shoulder Stabilization

Utilizing fresh distal tibia allograft in anterior glenoid reconstruction has emerged as a highly advantageous approach in addressing instances of failed anterior shoulder stabilization with glenoid bone loss. This procedure offers several benefits, including the absence of donor-site morbidity, restoration of significant glenoid defects, reestablishment of joint congruity with the humeral head, restoration of glenoid biomechanics, and the addition of cartilage to the glenoid. Furthermore, it provides a robust and reliable alternative for managing failed stabilization procedures, leading to improved clinical outcomes and a high graft healing rate, while maintaining a low occurrence of recurrent instability.

Arthroscopic Management of the Contact Athlete with Anterior Instability

Anterior glenohumeral instability is one of the most common injuries suffered from sport. Despite padding and conditioning, the shoulder joint remains particularly vulnerable to injury, especially in the setting of contact. The overall rate of anterior instability is reported to be 0.12 injuries per 1000 athlete exposures, although this is increased up to 0.40 to 0.51 in the contact athlete. Successful treatment requires consideration of restoring stability while minimizing loss of glenohumeral motion. Common treatment strategies involve addressing the pathology that results from anterior shoulder dislocation including labral detachment as well as bony defects to the humeral head and glenoid.

Comparison of Modified Latarjet Procedure With Bone Graft Versus Standard Latarjet Procedure: Evaluating Outcomes and Stability

BACKGROUND

The Latarjet procedure is a well-established technique for managing repeated anterior shoulder dislocation accompanied by massive glenoid bone loss. Aim of this article was to assess outcomes among modified Latarjet procedure using allograft from Iliac bone and a standard Latarjet procedure using the coracoid process.

METHODS

Six patients with recurrent anterior shoulder instability and significant glenoid bone loss were retrospectively analyzed. Three patients underwent the modified Latarjet procedure with iliac crest bone graft (Group A), and three underwent the standard Latarjet procedure (Group B). Outcomes were assessed at the 12-month follow-up, including shoulder stability, functional scores (Constant, the American Shoulder and Elbow Surgeons (ASES) score, and the Western Ontario Shoulder Instability Index (WOSI)), range of motion, complications, and return to sports.

RESULTS

Both groups showed improvements in stability and functional scores, with no recurrent instability reported. Group A demonstrated slightly higher functional scores and range of motion. One patient in Group A experienced donor site pain, while one patient in Group B showed significant graft resorption. Graft union was achieved in all patients. Two-thirds of patients in each group returned to their pre-injury level of sports participation.

CONCLUSION

Both techniques provided good clinical outcomes for anterior shoulder instability with glenoid bone loss. The modified Latarjet with iliac crest graft may offer slight advantages in functional outcomes and graft preservation but is associated with potential donor site morbidity. Larger, prospective studies are needed to definitively compare these techniques.

Anterior shoulder dislocation: A bibliometric analysis in the past two decades (2003-2022)

Background

Anterior shoulder dislocation is the most common type of shoulder dislocation and is easy to develop into recurrent type, causing economic burden to society. This study uses the bibliometric method to analyze the global research status, hotspots and trends of anterior shoulder dislocation, aiming to promote the exploration of anterior shoulder dislocation.

Methods

The literature on anterior shoulder dislocation in the past two decades were retrieved and downloaded from the Web of Science Core Collection (WOSCC) database. CiteSpace, VOSviewer and bibliometrix package of R software were used to conduct scientific bibliometric analysis of the literature. Finally, some statistical graphics were performed in Graphpad Prism.

Results

A total of 3914 publications related to anterior shoulder dislocation from 2003 to 2022 were retrieved and screened from the WOSCC database. The ranking of the analysis results showed that Provencher MT was the author with the highest frequency of occurrence. Rush University was the most notable contributor. The American Journal of Sports Medicine was the most comprehensive journal. The United States was the most prominent country. Keywords related to surgical treatment were more significant than others.

Conclusion

In the past two decades, the research output on anterior shoulder dislocation have been increasing year by year. The focus has gradually shifted to surgical treatment. Surgical treatment may continue to be the research hotspots in this field in the future.

Treatment of Shoulder Cartilage Defects in Athletes

Articular cartilage defects in the glenohumeral joint may be found in laborers, the elderly, and young athletes, among others. Various factors can contribute to cartilage damage, including prior surgery, trauma, avascular necrosis, inflammatory arthritis, joint instability, and osteoarthritis. There is a wide variety of treatment options, from conservative treatment, injections, and surgical options, including arthroscopic debridement, microfracture, osteochondral autograft transfer, osteochondral graft transplantation, autologous chondrocyte implantation, and the newly emerging techniques such as biologic augmentation. There is a challenge to determine the optimal treatment options, especially for young athletes, due to limited outcomes in the literature. However, there are many options which are viable to address osteochondral defects of the glenohumeral joint.

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.

Controversies in surgical management of anterior shoulder instability. State of the Art

Arthroscopic Bankart repair (ABR) has been accepted as a standard procedure for anterior shoulder instability with a minimum or no glenoid bone loss and an on-track Hill-Sachs lesion if present. However, several controversies exist in the surgical treatment of anterior shoulder instability. This article will discuss some of these controversies in, "simple," dislocations (without bone loss) as well as, "complex," (with critical bone loss). Determining which patients will benefit from an arthroscopic procedure depends on multiple factors including age, activity level, adequate determination of bone loss, performed with feasible and reliable imaging techniques. In the absence of concomitant significant bony and soft tissue pathology, ABR alone can provide satisfactory clinical results on a long-term basis. Controversies, including whether to remove cartilage from the edge of the glenoid, knotted versus knotless anchors, and routine rotator interval closure, still exist. In cases with significant bone loss, several bone restoring procedures have been described, such as, the Latarjet procedure, iliac crest bone graft, arthroscopic anatomic glenoid reconstruction with a frozen distal tibial allograft, and fresh distal tibial allograft reconstruction. This article will address these controversies and provide guidance based on available published data.

The Subscapularis-Sparing "Flipped Latarjet" Procedure

The Latarjet procedure is a proven and effective operation to treat anterior shoulder instability. Especially in cases with anterior glenoid bone loss, the Latarjet operation is the most popular procedure to restore glenoid anatomy and avoid further dislocations. Next to the re-creation of the missing glenoid bone, the sling effect of the conjoint tendon transferred between a split in the subscapularis muscle is an important "soft tissue stabilizer" of the humeral head. However, it has been shown that the inferior part of the subscapularis muscle tends to degenerate, leading to fatty infiltration of the muscle itself. Also, exposure through the subscapularis split is technically demanding, and there is a risk of nerve damage due to the pulling forces of the retractors during open surgery. When performing the procedure arthroscopically, extremely low and medial portals are necessary to find a correct angle for the glenoid drilling when approaching from anterior. Neurovascular structures may be at risk during these surgical steps. The aim of the flipped Latarjet procedure is to facilitate a safe and reliable arthroscopic operation to anteriorly stabilize the shoulder by transferring the coracoid to the deficient glenoid without splitting the subscapularis muscle while keeping the benefits of a sling effect of the conjoined tendon.

Surgical considerations for glenoid bone loss in anterior glenohumeral instability: a narrative review

PURPOSE

Treatment algorithms may consider many factors like glenoid and humeral bone loss, or scores such as the instability severity index score (ISIS). As most studies only evaluate a part of these factors, there is still no evidence-based consensus estalished. Our study aims to summarize the surgical options for treatment of glenoid bone loss (GBL) in anterior shoulder instability.

METHODS

Based on the current available literature, surgical options including Bankart repair and glenoid bone augmentation should be considered while taking into consideration the degree of bone loss which has been divided into < 10%, 10-20% and > 20%.

RESULTS

There are many new techniques evolving including arthroscopic anatomic glenoid reconstruction with bone blocks.

CONCLUSION

Future long-term outcome studies and randomized controlled trials comparing established techniques will be needed for new evidence-based treatment algorithms.

Outcomes of total shoulder arthroplasty in patients with prior anterior shoulder instability: minimum 5-year follow-up

BACKGROUND

Patients with a history of anterior shoulder instability (ASI) commonly progress to glenohumeral arthritis or even dislocation arthropathy and often require total shoulder arthroplasty (TSA). The purposes of this study were to (1) report patient-reported outcomes (PROs) after TSA in patients with a history of ASI, (2) compare TSA outcomes of patients whose ASI was managed operatively vs. nonoperatively, and (3) report PROs of TSA in patients who previously underwent arthroscopic vs. open ASI management.

METHODS

Patients were included if they had a history of ASI and had undergone TSA ≥5 years earlier, performed by a single surgeon, between October 2005 and January 2017. The exclusion criteria included prior rotator cuff repair, hemiarthroplasty, or glenohumeral joint infection before the index TSA procedure. Patients were separated into 2 groups: those whose ASI was previously operatively managed and those whose ASI was treated nonoperatively. This was a retrospective review of prospective collected data. Data collected was demographic, surgical and subjective. The PROs used were the American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, QuickDASH (Quick Disabilities of the Arm, Shoulder and Hand) score, and 12-item Short Form physical component score. Failure was defined as revision TSA surgery, conversion to reverse TSA, or prosthetic joint infection. Kaplan-Meier survivorship analysis was performed.

RESULTS

This study included 36 patients (27 men and 9 women) with a mean age of 56.4 years (range, 18.8-72.2 years). Patients in the operative ASI group were younger than those in the nonoperative ASI group (50.6 years vs. 64.0 years, P < .001). Operative ASI patients underwent 10 open and 11 arthroscopic anterior stabilization surgical procedures prior to TSA (mean, 2 procedures; range, 1-4 procedures). TSA failure occurred in 6 of 21 patients with operative ASI (28.6%), whereas no failures occurred in the nonoperative ASI group (P = .03). Follow-up was obtained in 28 of 30 eligible patients (93%) at an average of 7.45 years (range, 5.0-13.6 years). In the collective cohort, the American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, QuickDASH (Quick Disabilities of the Arm, Shoulder and Hand) score, and 12-item Short Form physical component score significantly improved, with no differences in the postoperative PROs between the 2 groups. We found no significant differences when comparing PROs between prior open and prior arthroscopic ASI procedures or when comparing the number of prior ASI procedures. Kaplan-Meier analysis demonstrated a 79% 5-year survivorship rate in patients with prior ASI surgery and a 100% survivorship rate in nonoperatively managed ASI patients (P = .030).

CONCLUSION

At mid-term follow-up, patients with a history of ASI undergoing TSA can expect continued improvement in function compared with preoperative values. However, TSA survivorship is decreased in patients with a history of ASI surgery compared with those without prior surgery.

Distal Tibial Allograft for the Treatment of Anterior Shoulder Instability With Glenoid Bone Loss: A Systematic Review and Meta-analysis

BACKGROUND

The use of a distal tibial allograft (DTA) for reconstruction of a glenoid defect in anterior shoulder instability has grown significantly over the past decade. However, few large-scale clinical studies have investigated the clinical and radiographic outcomes of the DTA procedure.

PURPOSE

To conduct a systematic review and meta-analysis of clinical studies with data on outcomes and complications in patients who underwent the DTA procedure for recurrent anterior shoulder instability with glenoid bone loss.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A comprehensive search of major bibliographic databases was conducted for articles pertaining to the use of a DTA for the management of anterior shoulder instability with associated glenoid bone loss. Postoperative complications and outcomes were extracted and compiled in a meta-analysis.

RESULTS

Of the 8 included studies with 329 total participants, the mean patient age was 28.1 ± 10.8 years, 192 (83.8%) patients were male, and the mean follow-up was 38.4 ± 20.5 months. The overall complication rate was 7.1%, with hardware complications (3.8%) being the most common. Partial graft resorption was observed in 36.5% of the participants. Recurrent subluxation was reported in 1.2% of the participants, and recurrent dislocation prompting a reoperation was noted in 0.3% of the participants. There were significant improvements in clinical outcomes, including American Shoulder and Elbow Surgeons score (40.9-point increase; P < .01), Single Assessment Numeric Evaluation (47.2-point increase; P < .01), Western Ontario Shoulder Instability Index (49.4-point decrease; P < .01), Disabilities of the Arm, Shoulder and Hand (20.0-point decrease; P = .03), and visual analog scale (2.1-point decrease; P = .05). Additionally, postoperative shoulder range of motion significantly increased from baseline values.

CONCLUSION

The DTA procedure was associated with a low complication rate, good clinical outcomes, and improved range of motion among patients with anterior shoulder instability and associated glenoid defects.

Bulk osteochondral allograft for massive Hill-Sachs defect combined with Latarjet procedure for bipolar bone loss in anterior instability

A proportion of patients with anterior glenohumeral instability present with bipolar bone loss comprising large Hill-Sachs lesions and substantial glenoid defect. These are surgically difficult cases to treat. We describe a novel surgical procedure of bulk size-matched osteochondral allograft reconstruction for massive Hill-Sachs lesions combined with the Latarjet procedure for these challenging cases.

Distal Radius Allograft for Glenohumeral Instability: A Novel Osteochondral Allograft Reconstruction Option in the Setting of Glenoid Bone Loss

BACKGROUND

Distal tibial allograft (DTA) reconstruction for glenoid bone loss is nonanatomic, as it does not match the glenoid radius of curvature (ROC) in the anterior-posterior (AP) plane. The dorsal articular portion of the distal radius has not been previously described as an allograft reconstruction option for glenoid bone loss.

PURPOSE

To evaluate distal radius fresh-frozen allograft (DRA) as a potential match for glenoid reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eighteen fresh-frozen human cadaveric specimens-including 6 shoulder, 6 wrist, and 6 tibia specimens-were used. The ROC and the graft length were measured in the superior-inferior (SI) plane. A 30% defect was created in all glenoid specimens, and both DTAs and DRAs were harvested to assess graft fit after fixation. Computed tomography analysis was used to assess bony ROC and bone mineral density (BMD).

RESULTS

The cadaveric specimens had a mean age of 77 years. The mean SI glenoid length was 39.7 mm compared with 36.8 mm for the DRA and 30 mm for the DTA. The ROC in the SI plane was 29 ± 5.3 mm for the glenoid, 37.8 ± 4.9 mm for the DRA, and 24 ± 3.7 mm for the DTA. In the AP plane, the ROC was 39.6 ± 6.6 mm for the glenoid, 30.4 ± 18.6 mm for the DRA, and 126.3 ± 9.5 mm for the DTA. On computed tomography analysis, the ROC in the SI plane was 30.4 ± 1.5 mm for the glenoid, 30.3 ± 5.6 mm for the DRA, and 24.5 ± 9.4 mm for the DTA. In the AP plane, the ROC was 30.8 ± 2 mm for the glenoid, 19.1 ± 2.3 mm for the DRA, and 46.7 ± 21.7 mm for the DTA. The BMD was 226.3 ± 79 Hounsfield units (HU) for the glenoid, 228.5 ± 94.7 HU for the DRA, 235 ± 96.2 HU for the coracoid process, and 235.1 ± 84.6 HU for the DTA.

CONCLUSION

Compared with the DTA, the DRA had a greater mean graft length in the SI plane, providing utilization in cases of larger bony defects; the DRA has a more acute ROC in the AP plane (closer to that of the glenoid), providing a greater potential buttress to anterior humeral translation. Compared with currently utilized grafts, the DRA BMD was not significantly diminished. This study presents the DRA as a novel allograft reconstruction option in the setting of anterior glenoid bone loss; further biomechanical and clinical investigation is indicated.

Free Bone Block Procedures for Glenoid Reconstruction in Anterior Shoulder Instability

Advances in the understanding and management of bone loss in shoulder instability have led to the development of free bone block techniques as an alternative to the Latarjet procedure. These techniques have been proposed as a theoretically safer option to Latarjet, and there is growing clinical enthusiasm in their use. The purpose of this article was to contextualize the utilization of free bone block procedures in the current treatment paradigm of anterior shoulder instability and to review the history and common types of bone autograft (eg, iliac crest, distal clavicle, scapular spine) and allograft (eg, distal tibia, preshaped blocks) techniques and approaches, as well as their clinical effectiveness and safety.

A Systematic Review of Screw and Suture Button Glenoid Augmentation Constructs

Background

Glenohumeral dislocations often lead to glenoid bone loss and recurrent instability, warranting bony augmentation. While numerous biomechanical studies have investigated fixation methods to secure a graft to the glenoid, a review of available constructs has yet to be performed.

Purpose

To synthesize the literature and compare the biomechanics of screw and suture button constructs for anterior glenoid bony augmentation.

Study Design

Systematic review.

Methods

A systematic review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. There were 2 independent reviewers who performed a literature search using the PubMed, Embase, and Google Scholar databases of studies published between 1950 and 2020. Studies were included that compared the biomechanical outcomes of fixation for the treatment of anterior shoulder instability with glenoid bone loss.

Results

Overall, 13 of the 363 studies screened met the inclusion criteria. The included studies measured the biomechanical strength of screws or suture buttons on a cadaveric or synthetic Latarjet construct. Screws and suture buttons were biomechanically similar, as both constructs exhibited comparable loads at failure and final displacement. Screw type (diameter, threading, or composition) did not significantly affect construct strength, and double-screw fixation was superior to single-screw fixation. Additionally, 2 screws augmented with a small plate had a higher load at failure than screws that were not augmented. Unicortical double-screw fixation was inferior to bicortical double-screw fixation, although construct strength did not significantly decrease if 1 of these screws was unicortical. Further, 2 screws inserted at 15° off axis experienced significantly higher graft displacement and lower ultimate failure loads than those inserted at 0° parallel to the glenoid.

Conclusion

Suture buttons provided comparable strength to screws and offer an effective alternative to reduce screw-related complications. Augmentation with a small plate may clinically enhance construct strength and decrease complications through the dispersion of force loads over a greater surface area. Differences in screw type did not appear to alter construct strength, provided that screws were placed parallel to the articular surface and were bicortical.

Anterior Shoulder Instability and Open Procedures: History, Indications, and Clinical Outcomes

The shoulder, being the most mobile joint in the human body, is often susceptible to dislocations and subluxations more so than other joints. As such, shoulder instability constitutes a common complaint among patients worldwide, especially those who are young, participate in contact sports, and have increased innate flexibility in their joints. Management options in the setting of instability vary between conservative and surgical options that aim to mitigate symptoms and allow return of function. Surgical options can be arthroscopic and open, with a general shift among surgeons towards utilizing arthroscopic surgery in the past several decades. Nevertheless, open procedures still play a role in managing shoulder instability patients, especially those with significant bone loss, recurrent instability, coexisting shoulder pathologies, and high risk of failure with arthroscopic surgery. In these clinical settings, open procedures, like the Latarjet procedure, open Bankart repair, glenoid bone augmentation using iliac crest autograft or distal tibial allograft, and salvage options like glenohumeral arthrodesis and arthroplasty may show good clinical outcomes and low recurrence rates. Each of these open procedures possesses its own set of advantages and disadvantages and entails a specific set of indications based on published literature. It is important to cater treatment options to the individual patient in order to optimize outcomes and reduce the risk of complications. Future research on open shoulder stabilization procedures should focus on the long-term outcomes of recently utilized procedures, investigate different graft options for procedures involving bone augmentation, and conduct additional comparative analyses in order to establish concrete surgical management guidelines.

Acromion and Distal Clavicle Grafts for Arthroscopic Glenoid Reconstruction

BACKGROUND

We intended to determine if an acromion or distal clavicle bone graft could restore large glenoid defects using two novel, screw-free graft fixation techniques.

METHODS

Twenty-four sawbone shoulder models were divided into four groups (n = 6 per group) according to fixation technique and bone graft: (1) modified buckle-down technique with clavicle graft, (2) modified buckle-down technique with acromion graft, (3) cross-link technique with acromion graft, (4) cross-link technique with clavicle graft. Testing was performed sequentially in (1) intact models, (2) after creation of a 30% by-width glenoid defect and (3) after repair. The shoulder joint was translated anteriorly, and glenohumeral contact pressures and load were measured to quantify the biomechanical stability.

RESULTS

Maximum contact pressures were restored to 42-56% of intact glenoid using acromion and clavicle grafts with novel fixation techniques. Acromion grafts attained higher maximum contact pressures than clavicle grafts in all groups. Peak translational forces increased by 171-368% after all repairs.

CONCLUSIONS

This controlled laboratory study on sawbone models found that both the acromion and distal clavicle are suitable autologous bone graft options for treating large anterior glenoid defects, having appropriate dimensions and contours for reconstructing the glenoid arc. The modified buckle-down and cross-link techniques are two graft fixation techniques that restore stability to the shoulder joint upon repairing a large glenoid defect and are advantageous in being screw-free and simple to execute.

Bankart repair with subscapularis augmentation: A case control study

To examine the effect on functional shoulder scores of Bankart repair with arthroscopic subscapularis tendon augmentation applied to cases of anterior shoulder instability with < 25% glenoid defect and ligament-labral failure. A total of 83 patients underwent Bankart repair with subscapularis tendon augmentation between 2015 and 2021. The range of movement of the patients was measured by 2 doctors using a goniometer. The Constant Murley score, American Shoulder and Elbow Surgeons score, Rowe score, and the University of California at Los Angeles scores were recorded preoperatively and postoperatively. Statistically significant increases were determined in the postoperative functional scores compared to the preoperative values as mean 41.4 ± 2.08 unit increase in the Constant Murley score, mean 41.4 ± 1.8 unit increase in the American Shoulder and Elbow Surgeons score, mean 13.8 ± 1.45 unit increase in the University of California at Los Angeles and mean 49.3 ± 7.45 unit increase in the Rowe score (P = .001; P < .01). Compared with the preoperative evaluation, there was found to be a postoperative statistically significant unit decrease of 10.2 ± 1.47 in the external rotation measurement (P = .001; P < .01). The number of dislocations was determined to have a negative correlation with the internal rotation measurements (r = -0.305; P = .005; P < .01), and a weak negative statistically significant relationship with external rotation measurements (r = -0.329; P = .002; P < .01). Unlike other techniques, as this repair technique includes both the tendon and the capsule as a single piece, it was seen to be a sufficient and reliable technique that is easy-to apply.

Management of Shoulder Instability in Patients with Seizure Disorders

PURPOSE OF REVIEW

Patients with seizure disorders commonly suffer shoulder dislocations and subsequent instability. Due to high rates of recurrence and bone loss, management of this instability and associated pathology has proven to be more complex than that of patients without seizure disorders. The ultimate goal of this review is to outline the various treatment modalities and their respective outcomes in this complex patient population.

RECENT FINDINGS

Optimization of medical management of seizure disorders is imperative. However, despite these efforts, the incidence of post-operative seizure activity continues to be a concern. These subsequent episodes increase the risk of further instability and failure of surgical procedures. Overall, the use of soft tissue procedures has proven to result in increased recurrence of instability compared to bone-block augmenting and grafting procedures. There are a variety of bone-block procedures that have been described for anterior and posterior instability. Despite their success in decreasing further instability, they are associated with several complications that patients should be informed of. There is no consensus regarding the optimal surgical management of shoulder instability in patients with seizure activity. A multidisciplinary approach to the management of the seizure activity is paramount to the success of their treatment. Further studies are required to evaluate the optimal timing and type of surgical intervention for individualized cases.

Functional biomechanical comparison of Latarjet vs. distal tibial osteochondral allograft for anterior glenoid defect reconstruction

INTRODUCTION

Glenoid reconstruction is indicated for recurrent glenohumeral instability with significant glenoid bone deficiency. Coracoid autograft (Latarjet) and distal tibial osteochondral allograft (DTA) reconstructions have been used to successfully restore glenohumeral stability. Relative advantages and disadvantages associated with each reconstruction technique have been described. However, direct comparisons of functional glenohumeral biomechanics associated with Latarjet vs. DTA reconstruction are lacking. This study was designed to compare these 2 glenoid reconstruction techniques with respect to joint kinematics and cartilage pressure mapping using a robotic testing system.

METHODS

In accordance with institutional review board policies, human cadaveric shoulders (n = 8) were cyclically tested in the neutral position and 90° of external rotation with 60° and 90° of abduction under a 45-N joint-compression load to measure clinically relevant translations, loads, and torques. Joint contact pressure maps were obtained under a 120-N joint-compression load using pressure mapping sensors. After confirming that a 25% anterior glenoid defect resulted in glenohumeral dislocation, testing was performed to compare 3 conditions: native intact glenoid, 25% anterior glenoid defect with Latarjet reconstruction, and 25% anterior glenoid defect with DTA reconstruction. Analyses of variance and t tests were used to analyze data with statistical significance set at P < .05.

RESULTS

Significant differences in anterior translation, inferior drawer, anterior drawer, compression loads, horizontal abduction, negative elevation (adduction), and external rotation torques during cyclical testing in 90° of external rotation with 60° and/or 90° of abduction were noted when comparing the 2 different glenoid bone reconstruction techniques to native, intact shoulders. The only significant difference between Latarjet and DTA reconstructions for measured translations, loads, and torques was a significantly higher absolute maximum compressive load for Latarjet compared to DTA at 60° of abduction.

CONCLUSION

Latarjet coracoid osseous autograft and distal tibial osteochondral allograft reconstructions of large (25%) glenoid bone defects prevent failure (dislocation) and are associated with significant glenohumeral kinematic differences that largely confer less translation, load, and torque on the joint in abduction when compared to the native state. These findings suggest that these 2 surgical techniques exhibit similar glenohumeral kinematics such that each provides adequate functional stability following anterior glenoid bone reconstruction. Joint compression load and articular contact pressure distribution may favor distal tibial osteochondral allograft reconstruction for treatment of large (25%) anterior glenoid bone defects associated with shoulder instability.

High correlation between inner and outer glenoid circle diameters and its clinical relevance

PURPOSE

The majority of methods for measuring glenoid bone loss in shoulder instability use the best-fit circle following the inferior glenoid rim. However, there is no precise method on how to draw this circle, particularly in case of a missing rim segment. Defining the radius is a source of substantial error. It was hypothesized that there is a relationship between the best-fit inferior circle (inner circle), defined by Sugaya, and the circle tangent to the supra- and infra-glenoid tubercles (outer circle), defined by Itoi, thus allowing a more consistent appreciation of the paleo-glenoid.

METHODS

Ninety-five normal dry scapulae were examined. The specimens were digitally photographed obtaining perpendicular images of the glenoid cavity. Using HOROS® imaging software, a best-fit inferior circle (inner circle) and a second circle fitting the most inferior and superior points of the glenoid (outer circle) were drawn by two investigators. The diameters and areas of the circles were recorded. Two-way random-effects intra-class correlation coefficients (ICC) were used to measure intra- and inter-observer agreement. A Bayesian measurement-error regression model was used to determine the relationship between outer and inner circle measurements.

RESULTS

The mean glenoid height was 35.1 mm and the glenoid width 25.6 mm. The mean diameter of the outer circle was 35.7 ± 4.2 mm and the mean diameter of the inner circle was 26.8 ± 3.2 mm. ICC showed excellent inter- and intra-observer agreement for both the outer circle diameter (ICC ≥ 0.95) and inner circle diameter (ICC ≥ 0.93). The two diameters demonstrated a very strong significant Pearson correlation (0.92, p < 0.001) and the regression showed excellent model fit R² = 0.87. The areas of the two circles were also highly and significantly correlated (r = 0.94; p < 0.001). The ratio of inner circle to outer diameters was 0.74.

CONCLUSION

There is a strong correlation between the inner and outer glenoid circle diameters. This study sets the base for the use the combined outer and inner circle and its ratio to better appreciate the paleo-glenoid morphology and thus obtain a more reliable bone loss estimation. Application of this method aids in a more reliable estimation bone loss with potential benefit in surgical decision-making.

Arthroscopic Anatomic Glenoid Reconstruction in the Unstable Shoulder: Technique, Pearls, and Pitfalls

Background:

Anterior shoulder instability with glenoid bone loss is a complex condition. Bankart repairs have higher failure rate in this population and the Latarjet procedure is associated with a high complication rate (15%-30%). A recent technique, the arthroscopic anatomic glenoid reconstruction, safely uses distal tibial allograft to augment the glenoid.

Indications:

Glenoid or bipolar bone loss in the setting of shoulder instability.

Technique Description:

A diagnostic shoulder arthroscopy is performed to assess bone loss and capsulolabral tissue. After the preparation of the anterior glenoid, a bone block harvested from a distal tibial allograft is prepared. This technique uses the Halifax portal, a safe, far medial portal to insert the graft, and compress it onto the anterior glenoid using screws. A Bankart repair is then performed, to reduce the capsulolabral complex onto the glenoid.

Results:

Results at 2 years show a 92% to 100% union of the graft, no recurrence of instability, and improved patient-reported outcome scores. Graft remodeling is regularly observed on postoperative imaging. This procedure may be faster to learn and to perform compared to an arthroscopic Latarjet.

Discussion/Conclusion:

Arthroscopic anatomic glenoid reconstruction is a safe, minimally invasive procedure to address shoulder instability. It has low complication rate and is associated with improved patient-reported outcomes.

Patient Consent Disclosure Statement:

The author(s) attest 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.

Surgeon variation in glenoid bone reconstruction procedures for shoulder instability

BACKGROUND

Advances in the understanding and management of glenoid bone loss in shoulder instability have led to the development of alternative bony reconstruction techniques to the Latarjet using free bone grafts, but little is known about surgeon adoption of these procedures. This study sought to characterize surgeon variation in the use of glenoid bone reconstruction procedures for shoulder instability and ascertain reasons underlying procedure choice.

METHODS

A 9-question survey was created and distributed to 160 shoulder surgeons members of the PacWest Shoulder and Elbow Society, of whom 65 (41%) responded. The survey asked questions regarding fellowship training, years in practice, surgical volume, preferred methods of glenoid bone reconstruction, and reasons underlying treatment choice.

RESULTS

All surgeons completed a fellowship, with an equal number of sports medicine fellowship-trained (46%) and shoulder and elbow fellowship-trained (46%) physicians. The majority had been in practice for at least 6 years (6-10 years: 25%; >10 years: 59%). Most (78%) performed ≤10 glenoid bony reconstructions per year, and 66% indicated that bony procedures represented <10% of their total annual shoulder instability case volume. The open Latarjet was the preferred primary reconstruction method (69%), followed by open free bone block (FBB) (22%), arthroscopic FBB (8%), and arthroscopic Latarjet (1%). Distal tibia allograft (DTA) was the preferred graft (74%) when performing an FBB procedure, followed by iliac crest autograft (18%), and distal clavicle autograft (6%). The top 5 reasons for preferring Latarjet over FBB were the sling effect (57%), the autologous nature of the graft (37%), its robust clinical evidence (22%), low cost (17%), and availability (11%). The top 5 reasons for choosing an FBB procedure were less anatomic disruption (58%), lower complication rate (21%), restoration of articular cartilage interface (16%), graft versatility (11%), and technical ease (11%). Only 20% of surgeons indicated always performing a bony glenoid reconstruction procedure in the noncontact athlete with less than 20% glenoid bone loss. However, that percentage rose to 62% when considering a contact athlete with the same amount of bone loss.

CONCLUSIONS

Although open Latarjet continues to be the most popular glenoid bony primary reconstruction procedure in shoulder instability, nearly 30% of shoulder surgeons in the western United States have adopted FBB techniques as their preferred treatment modality--with DTA being the most frequently used graft. High-quality comparative clinical effectiveness research is needed to reduce decisional conflict and refine current evidence-based treatment algorithms.

Biomechanical Analysis of Posterior Open-Wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-Free, J-Shaped Iliac Crest Bone Graft

BACKGROUND

Posterior open-wedge osteotomy and glenoid reconstruction using a J-shaped iliac crest bone graft showed promising clinical results for the treatment of posterior instability with excessive glenoid retroversion and posteroinferior glenoid deficiency.

PURPOSE

To evaluate the biomechanical performance of the posterior J-shaped graft to restore glenoid retroversion and posteroinferior deficiency in a cadaveric shoulder instability model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A posterior glenoid open-wedge osteotomy was performed in 6 fresh-frozen shoulders, allowing the glenoid retroversion to be set at 0°, 10°, and 20°. At each of these 3 preset angles of glenoid retroversion, the following conditions were simulated: (1) intact joint, (2) posterior Bankart lesion, (3) 20% posteroinferior glenoid deficiency, and (4) posterior J-shaped graft (at 0° of retroversion). With the humerus in the Jerk position (60° of glenohumeral anteflexion, 60° of internal rotation), stability was evaluated by measuring posterior humeral head (HH) translation (in mm) and peak translational force (in N) to translate the HH over 25% of the glenoid width. Glenohumeral contact patterns were measured using pressure-sensitive sensors. Fixation of the posterior J-graft was analyzed by recording graft micromovements during 3000 cycles of 5-mm anteroposterior HH translations.

RESULTS

Reconstructing the glenoid with a posterior J-graft to 0° of retroversion significantly increased stability compared with a posterior Bankart lesion and posteroinferior glenoid deficiency in all 3 preset degrees of retroversion (P < .05). There was no significant difference in joint stability comparing the posterior J-graft with an intact joint at 0° of retroversion. The posterior J-graft restored mean contact area and contact pressure comparable with that of the intact condition with 0° of retroversion (222 vs 223 mm2, P = .980; and 0.450 vs 0.550 MPa, P = .203). The mean total graft displacement after 3000 cycles of loading was 43 ± 84 µm, and the mean maximal mediolateral graft bending was 508 ± 488 µm.

CONCLUSION

Biomechanical analysis of the posterior J-graft demonstrated reliable restoration of initial glenohumeral joint stability, normalization of contact patterns comparable with that of an intact shoulder joint with neutral retroversion, and secure initial graft fixation in the cadaveric model.

CLINICAL RELEVANCE

This study confirms that the posterior J-graft can restore stability and glenohumeral loading conditions comparable with those of an intact shoulder.

Primary Distal Tibia Allograft for Restoration of Glenohumeral Stability with Anterior Glenoid Bone Loss

Recurrent shoulder instability with glenoid bone deficiency remains an increasing risk for failed shoulder stabilization surgery. Numerous free bone block procedures for primary treatment of anterior shoulder stability have been introduced as an alternative for the Latarjet procedure, including both autografts and allografts. Among such options is the fresh distal tibial allograft (DTA), a dense weightbearing bone without donor site morbidity and excellent conformity to the native glenoid. The aim of this Technical Note is therefore to describe our surgical technique for use of fresh DTA as a free bone block choice in the setting of primary anterior glenoid reconstruction in a patient with recurrent shoulder instability.

Fresh Distal Tibial Allograft: An Updated Graft Preparation Technique for Anterior Shoulder Instability

Fresh distal tibia allograft (DTA) has been gaining popularity among surgeons as an anatomic reconstruction option for the treatment of significant glenoid bone loss. Fresh DTA results in a clinically stable joint with excellent clinical outcomes and minimal graft resorption, and it has similar outcomes as the Latarjet procedure. Proper graft preparation and fixation are critical to ensuring optimal outcomes. The purpose of this Technical Note is, therefore, to describe our updated technique for DTA preparation that highlights precise cutting anatomy, sizing options, and use of orthobiologics to optimize distal tibia graft union to the native glenoid surface.

The Cuistow: A Modified Arthroscopic Bristow Procedure for the Treatment of Recurrent Anterior Shoulder Instability

The rate of nonunion observed among the variety of Bristow-Latarjet procedures reportedly ranges from 9.4% to 28%¹. In Chinese timber buildings, the mortise-tenon joint is commonly utilized to connect beams to columns. Drawing inspirations from this concept, we created a bone trough in the glenoid neck to serve as a mortise and trimmed the coracoid graft to serve as a tenon, then fixed this mortise-tenon joint with a metal screw. Compared with a standard Bristow-Latarjet procedure, the key feature of this technique was that the coracoid process was placed into a trough (5 to 10 mm deep) in the glenoid neck, which substantially increased the bone contact area between the graft and glenoid neck. We called this surgical technique the Chinese unique inlay Bristow (Cuistow).

Description

Specific instruments have been designed to improve the safety and accuracy of the arthroscopic inlay Bristow procedure (Weigao, Shangdong, China). The posterior portal (A), superolateral portal (B), and 3 anterior portals (i.e., proximal [C], inferolateral [D], and inferomedial [E]) were utilized. General anesthesia and an interscalene block were administered with the patient in the beach-chair position. The surgical technique can be divided into 6 steps: (1) evaluation of the shoulder joint; (2) coracoid preparation, drilling, and osteotomy; (3) subscapularis splitting and labrum detachment; (4) glenoid preparation and drilling; (5) coracoid retrieval, trimming, transfer, and fixation; and (6) Bankart repair.

Alternatives

Soft-tissue capsulolabral repairs or bone reconstruction procedures are commonly performed for the treatment of anterior glenohumeral instability². The arthroscopic Bristow-Latarjet procedure is increasingly popular for the treatment of anterior shoulder instability with a substantial osseous defect of the glenoid³. Defects that are too large to be restored with the coracoid process can be treated with use of the Eden-Hybbinette procedure or a distal tibial allograft^4,5.

Rationale

This procedure was inspired by the structure of mortise-tenon joints, resulting in a modified version of the Bristow-Latarjet technique in which the coracoid process is trimmed and placed into a trough (5 to 10 mm deep) in the glenoid neck. This procedure substantially increases the contact area between the fresh bone surface and the coracoid and glenoid neck. Another important advantage of this technique is that it can facilitate accurate positioning of the coracoid on the glenoid. This procedure resulted in a high rate of graft healing, excellent functional outcomes (Rowe and American Shoulder and Elbow Surgeons Shoulder scores), and a high rate of return to sport⁶. Currently, indications of this procedure are (1) participation in high-demand sports (i.e., collision and overhead) combined with the presence of a glenoid defect involving <25% of the glenoid, or (2) any glenoid defect involving 10% to 25% of the glenoid.

Expected Outcomes

Increased bone-contact area and accurate positioning of the graft helped to facilitate osseous union, with a union rate of 96.1% at 12 months postoperatively. The clinical outcomes were excellent, with a high rate of return to sport (87%) at a minimum of 3 years of follow-up⁶.

Important Tips

When the coracoid is retrieved through portal D (the inferolateral portal), there is a risk of stretching the musculocutaneous nerve.Trimming the coracoid graft could lead to stretching of the graft and the surrounding soft tissue, resulting in overstretching of the musculocutaneous nerve.To minimize the risk of musculocutaneous nerve injury, (1) the graft should be gently retrieved through portal D, (2) the graft should be trimmed with caution without overstretching it and surrounding soft tissue, and (3) a cannula should be utilized when driving the screw to fix the graft in order to avoid the surrounding soft tissue.

Acronyms & Abbreviations

RHD = right-hand dominantMRA = magnetic resonance angiography3D-CT = 3-dimensional computed tomographyPDS = polydioxanone sutureMCN = musculocutaneous nerve.

Editorial Commentary: Buttoning Up After Recurrent Anterior Shoulder Instability: The Eden-Hybinette Procedure Is an Effective Salvage After Failed Latarjet

Operative management of anterior glenohumeral dislocation can confer significant improvements in subjective shoulder function, pain, and overall stability. Although the coracoid-based Latarjet procedure has long been considered the ultimate treatment for complex anterior shoulder instability with glenoid or bipolar bone loss, few authors have considered the unimaginable question: what do you do when a patient fails Latarjet? A modified arthroscopic technique of the Eden-Hybinette procedure allows for revision anterior glenoid augmentation of critical glenoid bone loss with autologous tricortical iliac crest, while suture button fixation may obviate hardware complications previously seen with bicortical screw fixation. Although distal tibial allograft provides excellent congruity, viable articular cartilage, and no harvest site morbidity, financial costs and graft availability must also be considered. With favorable patient-reported outcomes, excellent rates of radiographic union, and reliable return to sport, the Eden-Hybinette procedure with suture button-based construct offers a viable alternative for patients with advanced glenoid bone loss (>20%) or revision scenarios.

A review of bone grafting techniques for glenoid reconstruction

BACKGROUND

Traumatic anterior shoulder dislocations can cause bony defects of the anterior glenoid rim and are often associated with recurrent shoulder instability. For large glenoid defects of 20-30% without a mobile bony fragment, glenoid reconstruction with bone grafts is often recommended. This review describes two broad categories of glenoid reconstruction procedures found in literature: coracoid transfers involving the Bristow and Latarjet procedures, and free bone grafting techniques.

METHODS

An electronic search of MEDLINE and PubMed was conducted to find original articles that described glenoid reconstruction techniques or modifications to existing techniques.

RESULTS

Coracoid transfers involve the Bristow and Latarjet procedures. Modifications to these procedures such as arthroscopic execution, method of graft attachment and orientation have been described. Free bone grafts have been obtained from the iliac crest, distal tibia, acromion, distal clavicle and femoral condyle.

CONCLUSION

Both coracoid transfers and free bone grafting procedures are options for reconstructing large bony defects of the anterior glenoid rim and have had similar clinical outcomes. Free bone grafts may offer greater flexibility in graft shaping and choice of graft size depending on the bone stock chosen. Novel developments tend towards minimising invasiveness using arthroscopic approaches and examining alternative non-rigid graft fixation techniques.

Editorial Commentary: Clinical Improvements of Superior Capsular Reconstruction Are Not Due to Maintained Dynamic Acromiohumeral Distance

Biomechanical data often help inform clinical decision-making in orthopaedic surgery. However, there are times when the biomechanical data and clinical data do not align. This is seen in cases of statistical but clinically irrelevant differences. This is also seen at times in cases of demonstrated clinical improvements with a poorly understood mechanism. Superior capsular reconstruction has gained significant traction since the original description in 2012. It has taken a central role in the armamentarium of treatment options of irreparable rotator cuff tears. There is robust published literature on the time zero biomechanics of superior capsular reconstruction and its stabilizing effects on the glenohumeral joint, especially with regards to superior migration of the humeral head. There also is demonstrated good early patient-reported outcomes with superior capsular reconstruction. However, the cause and effect may not be as simple as the biomechanical studies may suggest, and the underlying mechanism of why the superior capsular reconstruction appears to improve early outcomes remains poorly understood. These mechanisms are important to understand in order to inform technique changes and improvements and help us optimize treatment of the patient with an irreparable rotator cuff tear.

Unacceptable failure of osteochondral glenoid allograft for biologic resurfacing of the glenoid

Purpose

Glenohumeral osteoarthritis (OA) represents a challenging problem in young, physically active patients. It was the purpose of this investigation to evaluate the results of a pilot study involving glenoid resurfacing with a glenoid allograft combined with a hemiarthroplasty on the humeral side.

Methods

Between April 2011 to November 2013, 5 patients (3 men, 2 women, mean age 46.4, range 35-57) with advanced OA of the glenohumeral joint, were treated with a humeral head replacement combined with replacement of the glenoid surface with an osteochondral, glenoid allograft.

Results

Overall, clinically, there was one excellent, one satisfactory and three poor results. Mean preoperative subjective shoulder value (SSV) was 34% (range: 20-50%) and preoperative relative Constant-Murley-Score (CSr) was 43 points (range: 29-64 points). Three patients with poor results had to be revised within the first three years. Their mean pre-revision SSV and CSr were 38% (range: 15-80%) and 36 points (range: 7-59 points) respectively. One patient was revised 9 years after the primary procedure with advanced glenoid erosion and pain and one patient has an ongoing satisfactory outcome without revision. Their SSVs were 60% and 83%, their CSr were 65 points and 91 points, 9 and 10 years after the primary procedure, respectively. Mean follow-up was 7 years (2-10 years) and mean time to revision was 4 years (range: 1-9 years).

Conclusion

The in-vivo pilot study of a previously established in-vitro technique of osteochondral glenoid allograft combined with humeral HA led to three early failures and only one really satisfactory clinical outcome which, however, was associated with advanced glenoid erosion. Osteochondral allograft glenoid resurfacing was associated with an unacceptable early failure rate and no results superior to those widely documented for HA or TSA, so that the procedure has been abandoned.

Level of evidence

Level IV, Case Series, Treatment Study.

Anterior Glenoid Reconstruction With Distal Tibial Allograft: Biomechanical Impact of Fixation and Presence of a Retained Lateral Cortex

Background:

Glenoid reconstruction with distal tibial allograft (DTA) is a known surgical option for treating recurrent glenohumeral instability with anterior glenoid bone loss; however, biomechanical analysis has yet to determine how graft variability and fixation options alter the torque of screw insertion and load to failure.

Hypothesis:

It was hypothesized that retention of the lateral cortex of the DTA graft and the presence of a washer with the screw will significantly increase the maximum screw placement torque as well as the load to failure.

Study Design:

Controlled laboratory study.

Methods:

Whole, fresh distal tibias were used to harvest 28 DTA grafts, half of which had the lateral cortex removed and half of which had the lateral cortex intact. The grafts were secured to polyurethane solid foam blocks with a 2-mm epoxy laminate to simulate a glenoid with an intact posterior glenoid cortex. Grafts underwent fixation with 4.0-mm cannulated drills, and screws and washers were used for half of each group of grafts while screws alone were used for the other half, creating 4 equal groups of 7 samples each. A digital torque-measuring screwdriver recorded peak torque for screw insertion. Constructs were then tested in compression with a uniaxial materials testing system and loaded in displacement control at 100 mm/min until at least 3 mm of displacement occurred. Ultimate load was defined as the load sustained at clinical failure.

Results:

The use of a washer significantly improved the ultimate torque that could be applied to the screws (+cortex and +washer = 12.42 N·m [SE, 0.82]; –cortex and +washer = 10.54 N·m [SE, 0.59]) (P < .0001), whereas the presence of the native bone cortex did not have a significant effect (+cortex and –washer = 7.83 N·m [SE, 0.40]; –cortex and –washer = 8.03 N·m [SE, 0.56]) (P = .181).

Conclusion:

In a hybrid construct of fresh cadaveric DTA grafts secured to a foam block glenoid model, the addition of washers was more effective than the retention of the lateral distal tibial cortex for both load to failure and peak torque during screw insertion.

Clinical Relevance:

This biomechanical study is relevant to the surgeon when choosing a graft and selecting fixation options during glenoid reconstruction with a DTA graft.

Advanced 3-Dimensional Characterization of Hill-Sachs Lesions in 100 Anterior Shoulder Instability Patients

PURPOSE

We sought to qualitatively and quantitatively describe characteristics of Hill-Sachs lesions (HSL) in a cohort of anterior shoulder instability patients using advanced 3-dimensional (3-D) modeling software and assess the impact of various HSL parameters on the HSL volume, location, and orientation in patients with anterior shoulder instability.

METHODS

A total of 100 recurrent anterior instability patients with evidence of HSL with a mean age of 27.2 years (range = 18 to 43 years) were evaluated. Three-dimensional models of unilateral proximal humeri were reconstructed from CT scans, and the volume, surface area (SA), width, and depth of identified HSLs were quantified along with their location (medial, superior, and inferior extent). Multiple angular orientation measures of HSLs were recorded, including Hill-Sachs rim (HSLr) angle in order to classify the level and location of potential humeral head engagement. Mann-Whitney U test assessed the relationship between measured parameters.

RESULTS

By volume, larger HSL had greater humeral head surface area (HH SA) loss (P = .001), HSL width (P = .001), were more medial (P = .015), and more inferior (P = .001). Additionally, more medial lesions had greater HSLr angles (P = 0.001). The mean depth, width, and volume of HSLs were 3.3 mm (range = 1.2-7.1 mm), 16.0 mm (range = 6.2-30.4 mm) and 449.2 mm³ (range = 62.0-1365.6 mm³), respectively. The medial border of the HSL extended to 17.2 ± 4.4 (range = 9.3-28.3 mm) off the most medial edge of the HH cartilage margin (medialization). The mean HSLr was 29.3 ± 10.5°.

CONCLUSION

There was a statistically significant association between HSL medialization and HSL volume, position, and orientation. More medialized HSL have larger volume, greater width, more SA loss and higher lesion angles and are more inferior in the humeral head. As it has been established that more medialized lesions have poorer clinical outcomes, this study highlights that HS lesions have varying angles and medialization, which may portend eventual treatment and outcomes.

LEVEL OF EVIDENCE

IV, case series.

Salvage Iliac Crest Bone Grafting for a Failed Latarjet Procedure: Analysis of Failed and Successful Procedures

BACKGROUND

The Latarjet is a successful procedure but can be associated with significant complications, including failure. Iliac crest bone grafting (ICBG) is one of the salvage options for such failure.

PURPOSE

To analyze factors associated with failure or success to restore shoulder stability with ICBG after Latarjet failure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty consecutive patients with recurrence of instability after a Latarjet procedure underwent revision using ICBG. Sixteen patients (80%) with a mean age of 35.0 years (range, 25-55) could be personally reexamined clinically and radiographically (including computed tomography scan) after a mean follow-up of 4.5 years (range, 2-8). Twelve patients had redislocation and 4 had recurrent subluxation after the Latarjet.

RESULTS

Salvage ICBG failed in 7 patients because of recurrent dislocations, with 5 necessitating reoperations: 2 arthrodeses, 1 reverse total shoulder arthroplasty, 1 repeat ICBG, and 1 Hill-Sachs allograft reconstruction and Bankart repair. Factors associated with ICBG failure were multidirectional instability (n = 2), subscapularis insufficiency (n = 1), uncontrolled seizures (n = 1), static inferior glenohumeral subluxation (n = 1), total graft resorption (n = 1), and voluntary dislocation attributed to schizoaffective disorder (n = 1). The initial Latarjet graft was malpositioned (too medial) in 3 of these patients. In patients without recurrent instability (n = 9), reasons for Latarjet failure were graft related: 6 graft avulsions, 2 graft resorptions, and 1 medial graft malpositioning. The mean absolute Constant score (62 to 87 points, P = .012) and relative Constant score (66% to 91%, P = .012), pain (10 to 15 points, P < .001), and Subjective Shoulder Value (31% to 85%, P = .011) in the group with a successful procedure were significantly improved over the preoperative state, and the total Western Ontario Shoulder Instability Index averaged 64% at final follow-up. Except in 1 case of major resorption, mild graft resorption or none was observed in successful procedures. Axial and sagittal graft positioning was good in all 9 patients.

CONCLUSIONS

Salvage ICBG for failed Latarjet procedures failed in 7 of 16 patients. It was successful in patients with clearly graft-related factors of the initial Latarjet procedure. However, patients with unclear instability symptoms, subscapularis insufficiency, inferior subluxation, uncontrolled seizures, or psychological disorders were poor candidates for salvage ICBG, underlining the importance of careful patient selection for the initial Latarjet procedure and for salvage ICBG.

Current concepts in anterior glenohumeral instability: diagnosis and treatment

The glenohumeral joint is the most dislocated articulation, accounting for more than 50% of all joint dislocations. The reason behind shoulder instability should be investigated in detail for successful management, and the treatment plan should be individualized for all patients. Several classification systems have been proposed for glenohumeral instability. A physical exam is mandatory no matter what classification system is used. When treating patients with anterior shoulder instability, surgeons need to be aware of the critical size of the bone loss, which is commonly seen. The glenoid track concept was clinically adopted, and the measurement of the glenoid track for surgical decision-making is recommended. Detailed assessment of existing soft tissue injury to the labrum, capsule, glenohumeral ligaments, and rotator cuff is also mandatory as their presence influences the surgical outcome. Rehabilitation, arthroscopic repair techniques, open Bankart procedure, capsular plication, remplissage, Latarjet technique, iliac crest, and other bone grafts offer the surgeon different treatment options according to the type of patient and the lesions to be treated. Three-dimensional (3D) technologies can help to evaluate glenoid and humeral defects. Patient-specific guides are low-cost surgical instruments and can be used in shoulder instability surgery. 3D printing will undoubtedly become an essential tool to achieve the best results in glenohumeral instability surgery.

Arthroscopic Iliac Bone Grafting for Traumatic Anterior Shoulder Instability With Significant Glenoid Bone Loss Yields Low Recurrence and Good Outcome at a Minimum of Five-Year Follow-Up

PURPOSE

The purpose of this study was to investigate the clinical and radiographic outcomes of arthroscopic iliac bone grafting with capsulolabral reconstruction for severe glenoid bone loss with a minimum of 5 years' follow-up.

METHODS

The inclusion criterion was shoulders that underwent arthroscopic iliac bone grafting for >20%-25% glenoid defect between January 2007 and April 2014, and the exclusion criterion was <5 years' follow-up. Iliac crest bone grafts of approximately 2.0 cm length and 0.8 cm height were arthroscopically fixed to the anterior glenoid using 2 cannulated screws followed by capsulolabral repair. Rowe score, Western Ontario Shoulder Instability Index (WOSI), and passive range of motion were evaluated. Radiographic findings including the Kellgren and Lawrence osteoarthritis grade and graft integration on 3-dimensional computed tomography at the final follow-up were also evaluated.

RESULTS

Forty-eight shoulders met the inclusion criteria, and 24 shoulders with ≥5 years' follow-up were included (1 died; 23 were lost follow-up): 22 males, 2 females; a mean age at surgery, 30 years (range, 18-52 years); a mean follow-up of 8 years (range, 5-11 years). The mean preoperative glenoid bone defect was 22% (range, 20%-28%). All shoulders had a Hill-Sachs lesion including 4 on-track lesions. One shoulder experienced traumatic redislocation at 5 years after surgery. The scores significantly improved: Rowe score, 19 ± 8 to 94 ± 8 (P < .001); WOSI, 1547 ± 241 to 439 ± 318 (P < .001). Postoperative flexion showed significant improvement from 158 ± 18 to 169 ± 11 (P = .008), whereas internal rotation deteriorated from T8 ± 3 to T10 ± 3 (P = .005). Graft integration showed remodeling in 54% and excessive absorption in 13%. Osteoarthritis grades progressed significantly (P < .001), but only grade 1 osteoarthritic changes were seen, except for 4 shoulders with grade 2 osteoarthritis.

CONCLUSIONS

Arthroscopic iliac bone grafting for traumatic anterior shoulder instability with severe glenoid bone loss yielded satisfactory outcomes with mid-term follow-up. Arthritic changes progressed in half of the shoulders; however, most shoulders only demonstrated grade 1 osteoarthritis.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Anterior and posterior glenoid bone augmentation options for shoulder instability: state of the art

Bony lesions are highly prevalent in anterior shoulder instability and can be a significant cause of failure of stabilisation procedures if they are not adequately addressed. The glenoid track concept describes the dynamic interaction between the humeral head and glenoid defects in anterior shoulder instability. It has been beneficial for understanding the role played by bone defects in this entity. As a consequence, the popularity of glenoid augmentation procedures aimed to treat anterior glenoid bone defects; reconstructing the anatomy of the glenohumeral joint has risen sharply in the last decade. Although bone defects are less common in posterior instability, posterior bone block procedures can be indicated to treat not only posterior bony lesions, attritional posterior glenoid erosion or dysplasia but also normal or retroverted glenoids to provide an extended glenoid surface to increase the glenohumeral stability. The purpose of this review was to analyse the rationale, current indications and results of surgical techniques aimed to augment the glenoid surface in patients diagnosed of either anterior or posterior instability by assessing a thorough review of modern literature. Classical techniques such as Latarjet or free bone block procedures have proven to be effective in augmenting the glenoid surface and consequently achieving adequate shoulder stability with good clinical outcomes and early return to athletic activity. Innovations in surgical techniques have permitted to perform these procedures arthroscopically. Arthroscopy provides the theoretical advantages of lower morbidity and faster recovery, as well as the identification and treatment of concomitant pathologies.

Clinical Outcomes of Shoulder Stabilization in Females With Glenoid Bone Loss

Background

Nearly all studies describing shoulder stabilization focus on male patients. Little is known regarding the clinical outcomes of female patients undergoing shoulder stabilization, and even less is understood about females with glenoid bone loss.

Purpose

To assess the clinical outcomes of female patients with recurrent anterior shoulder instability treated with the Latarjet procedure.

Study Design

Case series; Level of evidence, 4.

Methods

All cases of female patients who had recurrent anterior shoulder instability with ≥15% anterior glenoid bone loss and underwent the Latarjet procedure were analyzed. Patients were evaluated after a minimum 2-year postoperative period with scores of the American Shoulder and Elbow Surgeons form, Simple Shoulder Test, and pain visual analog scale.

Results

Of the 22 patients who met our criteria, 5 (22.7%) were lost to follow-up, leaving 17 (77.2%) available for follow-up with a mean ± SD age of 31.7 ± 12.9 years. Among these patients, 16 (94.1%) underwent 1.6 ± 0.73 ipsilateral shoulder operations (range, 1-3) before undergoing the Latarjet procedure. Preoperative indications for surgery included recurrent instability with bone loss in all cases. After a mean follow-up of 40.2 ± 22.9 months, patients experienced significant score improvements in the American Shoulder and Elbow Surgeons form, Simple Shoulder Test, and pain visual analog scale (P < .05 for all). There were 2 reoperations (11.8%). There were no cases of neurovascular injuries or other complications.

Conclusion

Female patients with recurrent shoulder instability with glenoid bone loss can be successfully treated with the Latarjet procedure, with outcomes similar to those of male patients in the previously published literature. This information can be used to counsel female patients with recurrent instability with significant anterior glenoid bone loss.

[Shoulder instability: review of current concepts of diagnosis and treatment]

OBJECTIVE

To conduct a systematic review of modern literature data on the modern approaches in diagnosis and treatment of shoulder instability.

MATERIAL AND METHODS

Searching for literature data was performed using the Pubmed and Google Scholar databases.

RESULTS

The authors analyzed the results of conservative treatment of patients with shoulder instability and emphasized higher risk of instability recurrence, degeneration of anatomical structures and functional impairment in these patients. Surgery is advisable to restore shoulder stability and normalize its function. Several methods for stabilizing the shoulder have been proposed.

The approaches to diagnosis and treatment of shoulder instability have been updated.

CONCLUSION

Successful treatment of shoulder instability is based on qualitative and complete assessment of soft tissues and bone structures. An individual approach considering bone tissue deficiency and individual needs of the patient is required.

Arthroscopic Glenoid Reconstruction With Iliac Crest Bone Block Transfer in the Beach Chair Position

Large anterior glenoid defects pose significant challenges for shoulder stability. Arthroscopic glenoid reconstruction techniques using distal tibia allograft have been proposed as alternatives to open or arthroscopic Latarjet procedures but can increase operating room costs. Iliac crest bone block autograft is a cost-effective option without concern for the graft being undersized. Previous techniques have described arthroscopic glenoid reconstruction in the lateral position, but the beach chair position provides ease of access to both the iliac crest bone graft harvest and arthroscopic bone transfer, as well as facilitates possible conversion to an open approach if necessary. We present our surgical technique for performing an arthroscopic glenoid reconstruction with iliac crest autograft bone block transfer in the beach chair position.

Anterior Glenohumeral Instability in the Adolescent Athlete

Glenohumeral instability is multifactorial and has both static and dynamic elements. The initial management of first-time dislocations has become increasingly controversial, although recent evidence supports operative treatment for adolescents who participate in contact sports. Risk factors for recurrent glenohumeral instability include adolescent age, hyperlaxity, glenoid bone loss, off-track Hill-Sachs lesions, and fixation with <=3 anchors. High rates of return to sport can be expected when the surgical plan is tailored to individual pathology.

Outcomes of the Latarjet Procedure Versus Free Bone Block Procedures for Anterior Shoulder Instability: A Systematic Review and Meta-analysis

BACKGROUND

Free bone block (FBB) procedures for anterior shoulder instability have been proposed as an alternative to or bail-out for the Latarjet procedure. However, studies comparing the outcomes of these treatment modalities are limited.

PURPOSE

To systematically review and perform a meta-analysis comparing the clinical outcomes of patients undergoing anterior shoulder stabilization with a Latarjet or FBB procedure.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

PubMed, Embase, and the Cochrane Library databases were systematically searched from inception to 2019 for human-participants studies published in the English language. The search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement including studies reporting clinical outcomes of patients undergoing Latarjet or FBB procedures for anterior shoulder instability with minimum 2-year follow-up. Case reports and technique articles were excluded. Data were synthesized, and a random effects meta-analysis was performed to determine the proportions of recurrent instability, other complications, progression of osteoarthritis, return to sports, and patient-reported outcome (PRO) improvement.

RESULTS

A total of 2007 studies were screened; of these, 70 studies met the inclusion criteria and were included in the meta-analysis. These studies reported outcomes on a total of 4540 shoulders, of which 3917 were treated with a Latarjet procedure and 623 were treated with an FBB stabilization procedure. Weighted mean follow-up was 75.8 months (range, 24-420 months) for the Latarjet group and 92.3 months (range, 24-444 months) for the FBB group. No significant differences were found between the Latarjet and the FBB groups in the overall random pooled summary estimate of the rate of recurrent instability (5% vs 3%, respectively; P = .09), other complications (4% vs 5%, respectively; P = .892), progression of osteoarthritis (12% vs 4%, respectively; P = .077), and return to sports (73% vs 88%; respectively, P = .066). American Shoulder and Elbow Surgeons scores improved after both Latarjet and FBB, with a significantly greater increase after FBB procedures (10.44 for Latarjet vs 32.86 for FBB; P = .006). Other recorded PRO scores improved in all studies, with no significant difference between groups.

CONCLUSION

Current evidence supports the safety and efficacy of both the Latarjet and FBB procedures for anterior shoulder stabilization in the presence of glenoid bone loss. We found no significant differences between the procedures in rates of recurrent instability, other complications, osteoarthritis progression, and return to sports. Significant improvement in PROs was demonstrated for both groups. Significant heterogeneity existed between studies on outcomes of the Latarjet and FBB procedures, warranting future high-quality, comparative studies.

Utility of Allograft Talus as a Source for Grafting of Concurrent Humeral and Glenoid Defects Associated With Anterior Glenohumeral Instability: An Anthropometric Analysis

PURPOSE

To compare morphologic data of the talus using magnetic resonance images with previously reported values of the humeral head and the glenoid as a potential graft source for both the humeral head as well as glenoid reconstruction in the setting of concomitant glenoid and humeral head defects.

METHODS

All magnetic resonance images of the ankle were reviewed for assessment of the morphology and variation of the talus among individuals. Patients with post-traumatic, osteoarthritic, or surgical changes to the distal tibia about the mid- or hind- foot, or patients with incomplete medical records were excluded. Radiographic parameters that were measured included the maximum vertical height (MVH), the height to the talar neck, the radius of curvature (ROC) of the talar dome, ROC of the subtalar joint, and the maximum medial-to-lateral width of the talar dome. Demographic data also were collected on each individual. Statistical analysis was performed via a linear regression model with backwards elimination to determine which demographic data correlated most strongly with talar anthropometric values.

RESULTS

A total of 82 study patients met inclusion criteria (59 male, 23 female; mean age 40.91 ± 14.69 years). Sex was found have a positive correlation of the following talar dimensions: MVH (P = .039), talar dome ROC (P < .001), and subtalar joint ROC (p = 0.001). Height was the most positive correlation for medial-to-lateral width (P < .001), height to the talar neck (P = .004), and also correlate for MVH (P = .004). Body mass index was found to have multicollinearity and was therefore not used as a variable.

CONCLUSIONS

Allograft talus appears to be a viable graft, as demonstrated in this anthropometric study for both reconstruction of the glenoid and humeral head when cases of bipolar glenohumeral bone loss are present.

CLINICAL RELEVANCE

This study aims to further evaluate potential allograft donor sites for bipolar lesions.

Arthroscopic Posterior Glenoid Reconstruction Using a Fresh Distal Tibia Allograft for Recurrent Posterior Instability

Posterior glenohumeral instability is a relatively uncommon cause of shoulder instability. Recurrent posterior instability with static posterior humeral head subluxation is often associated with critical glenoid bone loss. Unlike anterior instability, the amount of bone loss for posterior instability that requires surgical reconstruction remains a topic of debate. Several techniques have been described to treat critical bony defects in patients with recurrent posterior shoulder instability with the use of both autografts and allografts depending on the amount of bone loss present. Open posterior glenoid bone block procedure is associated with increased risk of complications and morbidity to the patient. As such, all-arthroscopic techniques have emerged with the advantage of allowing for the diagnosis and treatment of concomitant glenohumeral pathology and minimizing soft-tissue dissection through the posterior deltoid and rotator cuff muscles. Reported short-term outcomes of arthroscopic posterior bone block stabilization are promising; however, it remains a technically challenging procedure due to intra-articular graft insertion and subsequent fixation congruent to the posterior glenoid articular margin. We describe an all-arthroscopic technique using a fresh distal tibia allograft fixation using 2 partially threaded screws in conjunction with an arthroscopic Latarjet fixation set for a patient with recurrent posterior shoulder instability and associated glenoid bone loss.