Distal Tibia Allograft Glenoid Reconstruction in Recurrent Anterior Shoulder Instability: Clinical and Radiographic Outcomes

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.

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.

Surgical treatment of anterior glenohumeral instability: a historical review

BACKGROUND

Glenohumeral instability is a common pathology, particularly in young, active patients.

METHODS

A narrative review was performed to describe the history of surgical treatments for anterior shoulder instability.

RESULTS

Open surgical techniques were first described by Bankart in 1923. Techniques include both anatomic soft tissue repairs and nonanatomic procedures to provide constraint to motion and dislocation. Osseous techniques to address glenoid bone loss include both autograft techniques, such as the Latarjet procedure, and the use of various allografts. Technologic advances, particularly arthroscopy, have continued to drive the evolution of treatments. The concept of the glenoid track has furthered our understanding of this pathology to guide appropriate treatment to reduce recurrence.

CONCLUSIONS

Surgical treatment for anterior shoulder instability continues to evolve in an effort to restore function and prevent additional injury.

Osteochondral allografts for the treatment of shoulder instability

Aims

To systematically review the predominant complication rates and changes to patient-reported outcome measures (PROMs) following osteochondral allograft (OCA) transplantation for shoulder instability.

Methods

This systematic review, following PRISMA guidelines and registered in PROSPERO, involved a comprehensive literature search using PubMed, Embase, Web of Science, and Scopus. Key search terms included "allograft", "shoulder", "humerus", and "glenoid". The review encompassed 37 studies with 456 patients, focusing on primary outcomes like failure rates and secondary outcomes such as PROMs and functional test results.

Results

A meta-analysis of primary outcomes across 17 studies revealed a dislocation rate of 5.1% and an increase in reoperation rates from 9.3% to 13.7% post-publication bias adjustment. There was also a noted rise in conversion to total shoulder arthroplasty and incidence of osteoarthritis/osteonecrosis over longer follow-up periods. Patient-reported outcomes and functional tests generally showed improvement, albeit with notable variability across studies. A concerning observation was the consistent presence of allograft resorption, with rates ranging from 33% to 80%. Comparative studies highlighted similar efficacy between distal tibial allografts and Latarjet procedures in most respects, with some differences in specific tests.

Conclusion

OCA transplantation presents a promising treatment option for shoulder instability, effectively addressing both glenoid and humeral head defects with favourable patient-reported outcomes. These findings advocate for the inclusion of OCA transplantation in treatment protocols for shoulder instability, while also emphasizing the need for further high-quality, long-term research to better understand the procedure's efficacy profile.

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.

Graft Position, Healing, and Resorption in Anterior Glenohumeral Instability: A Comparison of 4 Glenoid Augmentation Techniques

Background

The success of glenoid augmentation procedures depends on accurate placement and healing of the graft to the glenoid. Different glenoid augmentation techniques have been described, but no comparative studies between them exist.

Purpose

To assess the bone graft position, healing, and resorption in a group of patients treated with 1 of 4 procedures: arthroscopic anterior bone-block procedure using either (1) fresh-frozen iliac crest allograft or (2) iliac crest autograft, (3) open Latarjet, or (4) arthroscopic Latarjet.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 40 patients (87.5% men; mean age, 29.5 ± 7.9 years) were included, with 10 patients in each of the procedure groups. The graft position in the axial and sagittal planes was assessed on postoperative computed tomography (CT). Graft healing and resorption were assessed in a second CT scan performed 1 year postoperatively. Qualitative variables were compared between the 4 procedures using the chi-square test, and quantitative variables were compared with the Student t test or Mann-Whitney U test.

Results

No differences were found between the procedures in the axial or sagittal position. The healing rate was significantly lower in the allograft bone-block group (20%) compared with the autograft bone-block (80%), open Latarjet (90%), and arthroscopic Latarjet (90%) groups (P < .001). Graft resorption developed in 17 of 40 (42.5%) cases overall. Osteolysis occurred in 100% of cases in the allograft bone-block group compared with 50% in the autograft group, 20% in the open Latarjet group, and 0% in the arthroscopic Latarjet group (P < .001). The glenoid surface area on 1-year CT scan was significantly lower in the allograft bone-block group compared with the autograft bone-block, open Latarjet, and arthroscopic Latarjet groups (P < .001).

Conclusion

Arthroscopic bone-block, open Latarjet, and arthroscopic Latarjet procedures provided accurate bone graft positioning. However, very high rates of osteolysis and nonunion were observed in the iliac crest fresh-frozen allograft bone-block procedure when compared with the other procedures.

Posterior Shoulder Instability, Part II-Glenoid Bone Grafting, Glenoid Osteotomy, and Rehabilitation/Return to Play-An International Expert Delphi Consensus Statement

PURPOSE

To establish consensus statements on glenoid bone grafting, glenoid osteotomy, rehabilitation, return to play, and follow-up for posterior shoulder instability.

METHODS

A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement.

RESULTS

All of the statements relating to rehabilitation, return to play, and follow-up achieved consensus. There was unanimous consensus that the following criteria should be considered: restoration of strength, range of motion, proprioception, and sport-specific skills, with a lack of symptoms. There is no minimum time point required to return to play. Collision athletes and military athletes may take longer to return because of their greater risk for recurrent instability, and more caution should be exercised in clearing them to return to play, with elite athletes potentially having different considerations in returning to play. The relative indications for revision surgery are symptomatic apprehension, multiple recurrent instability episodes, further intra-articular pathologies, hardware failure, and pain.

CONCLUSIONS

The study group achieved strong or unanimous consensus on 59% of statements. Unanimous consensus was reached regarding the criteria for return to play, collision/elite athletes having different considerations in return to play, indications for revision surgery, and imaging only required as routine for those with glenoid bone grafting/osteotomies at subsequent follow-ups. There was no consensus on optimal fixation method for a glenoid bone block, the relative indications for glenoid osteotomy, whether fluoroscopy is required or if the labrum should be concomitantly repaired.

LEVEL OF EVIDENCE

Level V, expert opinion.

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.

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.

Graft Resorption After Posterior Distal Tibial Allograft Augmentation for Posterior Shoulder Instability: A Case Report

CASE

A 19-year-old man underwent arthroscopic posterior glenoid reconstruction with a distal tibia allograft (DTA) after failing 2 posterior, soft-tissue instability surgeries. Although he experienced near-complete resolution of symptoms and return to sport, graft resorption was noted 7 months postoperatively. The patient underwent revision surgery for screw removal.

CONCLUSION

Graft resorption has not previously been reported in the setting of arthroscopic DTA use for posterior instability. It is believed that stress shielding contributed to resorption. In such situations, screw removal may be warranted. Consideration of alternative fixation techniques and additional investigation into the causes, clinical significance, and optimal management of posterior DTA resorption are warranted.

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.

Biomechanical Evaluation of the 2 Different Levels of Coracoid Graft Positions in the Latarjet Procedure for Anterior Shoulder Instability

Background

In the Latarjet procedure, the ideal placement of the coracoid graft in the medial-lateral position is flush with the anterior glenoid rim. However, the ideal position of the graft in the superior-inferior position (sagittal plane) for restoring glenohumeral joint stability is still controversial.

Purpose

To compare coracoid graft clockface positions between the traditional 3 to 5 o'clock and a more inferior (for the right shoulder) 4 to 6 o'clock with regard to glenohumeral joint stability in the Latarjet procedure.

Study Design

Controlled laboratory study.

Methods

A total of 10 fresh-frozen cadaveric shoulders were tested in a dynamic, custom-built robotic shoulder model. Each shoulder was loaded with a 50-N compressive load while an 80-N force was applied in the anteroinferior axes at 90° of abduction and 60° of shoulder external rotation. Four conditions were tested: (1) intact, (2) 6-mm glenoid bone loss (GBL), (3) Latarjet procedure fixed at 3- to 5-o'clock position, and (4) Latarjet procedure fixed at 4- to 6-o'clock position. The stability ratio (SR) and degree of lateral humeral displacement (LHD) were recorded. A 1-factor random-intercepts linear mixed-effects model and Tukey method were used for statistical analysis.

Results

Compared with the intact state (1.77 ± 0.11), the SR was significantly lower after creating a 6-mm GBL (1.14 ± 0.61, P = .009), with no significant difference in SR after Latarjet 3 to 5 o'clock (1.51 ± 0.70, P = .51) or 4 to 6 o'clock (1.55 ± 0.68, P = .52). Compared with the intact state (6.48 ± 2.24 mm), LHD decreased significantly after GBL (3.16 ± 1.56 mm, P < .001) and Latarjet 4 to 6 o'clock (5.48 ± 3.39 mm, P < .001). Displacement decreased significantly after Latarjet 3 to 5 o'clock (4.78 ± 2.50 mm, P = .04) compared with the intact state but not after Latarjet 4 to 6 o'clock (P = .71).

Conclusion

The Latarjet procedure in both coracoid graft positions (3-5 and 4-6 o'clock) restored the SR to the values measured in the intact state. A more inferior graft position (fixed at 4-6 o'clock) may improve shoulder biomechanics, but additional work is needed to establish clinical relevance.

Clinical Relevance

An inferior coracoid graft fixation, the 4- to 6-o'clock position, may benefit in restoring normal shoulder biomechanics after the Latarjet procedure.

Editorial Commentary: Both Bristow and Latarjet Procedures Result in Low Rates of Recurrent Shoulder Instability Despite Potential for Bone Resorption and Lack of Graft Healing

Anterior shoulder instability surgery has evolved over the decades, including both anatomic and nonanatomic repairs and reconstructions. Surgeons are continually advancing their skills and performing more of these procedures using arthroscopic as opposed to open techniques in patients with and without glenoid bone loss. However, there is a steep learning curve and increased technical demands when performing these procedures arthroscopically. Despite high success rates, bone graft resorption or lack of healing after Latarjet and Bristow procedures is well documented, and it is possible that patients develop enough scarring that their shoulders remain stable. Osteoarthritis after these nonanatomic procedures can occur making shoulder arthroplasty and reconstruction technically more challenging because of scarring and the altered anatomy. It remains to be seen whether these arthroscopic techniques as opposed to open surgery lessen the scarring and thus the technical demands of shoulder reconstruction in the small subset of patients who unfortunately develop symptomatic shoulder osteoarthritis. Therefore, in my practice, these techniques are carefully chosen for select patients. My indications for use of the Bristow procedure as a primary procedure for anterior shoulder instability are in patients who perform mixed martial arts fighting and high-level wrestlers without significant glenoid or humeral bone loss. My indications for the Latarjet procedure are in patients with chronic anterior instability and associated anterior glenoid bone loss 15% to 30%, off-track Hill-Sachs lesions, and revision surgery, particularly in high-demand contact and collision athletes. These 2 arthroscopic procedures, despite being nonanatomic, provide surgeons with excellent treatment options for those difficult patients with anterior shoulder instability. Despite high success rates with these arthroscopic procedures, patients should be counseled on the risks of graft resorption, graft nonunion, and possible shoulder osteoarthritis. The appropriate indications for these arthroscopic procedures can enhance the successful outcomes for high-risk patients with shoulder instability while also considering the possible long-term impacts of altering shoulder anatomy and scarring in the rare patient who develops shoulder osteoarthritis.

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.

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.

Arthroscopic Distal Clavicle Bone Block Technique for Anteroinferior Instability With Critical Bone Loss

Arthroscopic distal clavicle autograft represents a locally available source of autograft for bone block augmentation in patients with anterior shoulder instability with glenoid bone loss. Anatomic and biomechanical studies have supported distal clavicle autograft use as comparable to coracoid graft with regard to restoration of glenoid articular surface, with the theoretical advantage of minimizing complications associated with coracoid transfer procedures, such as neurologic injury and coracoid fracture. The current technique describes a modification of those previously described, including a mini-open approach for distal clavicle autograft harvest, orientation of the distal clavicle with the medial clavicle graft against the glenoid (congruent arc), an all-arthroscopic technique of graft passage, and graft placement and fixation using specialized drill guides and four suture buttons to reproducibly place and secure the graft with final capsulolabral advancement over the graft to render it extra-articular.

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.

The Arthroscopic Trillat Procedure Is a Valuable and Durable Treatment Option for Recurrent Anterior Instability Associated With Massive Irreparable Cuff Tears

PURPOSE

The purpose of the present study is to report the mid- and long-term clinical and radiologic outcomes of the arthroscopic Trillat for the treatment of recurrent anterior instability in patients with chronic massive irreparable rotator cuff tears (MIRCTs) and maintained active shoulder motion where reverse shoulder arthroplasty (RSA) is not indicated.

METHODS

Twenty-one consecutive patients (mean age 61 years) were identified and retrospectively reviewed. All patients had recurrent anterior dislocations and conserved active forward elevation and active external rotation. The MIRCTs included a retracted (stage 3) supraspinatus tear in 14%, a supra- and infraspinatus tear in 76.5%, and a 3-tendon tear in 14%. A closed-wedge osteotomy of the coracoid was performed, and the coracoid was fixed above the subscapularis with a cannulated screw (10 cases) or suture buttons (11 cases). We followed patients with x-rays and computed tomography scan at 6 months, along with Subjective Shoulder Value, visual analog scale, Walch, Constant, and Rowe scores. The mean clinical and radiographic follow-up was 58 months (24-145 months).

RESULTS

Overall, 96% (20/21) of the patients had a stable and functional shoulder and were satisfied with the procedure; no patient lost active shoulder motion. The Subjective Shoulder Value increased from 44% (10%-75%) to 94% (80%-100%), P < .001. The Constant and Rowe scores improved from 60 (25-81) to 81 (66-96) and from 54 (35 to 65) to 92 (70-100), respectively (P < .001). Among the 13 patients practicing sports before surgery, 10 (77%) went back to sports. At last follow-up, only 1 patient was revised to RSA.

CONCLUSIONS

The arthroscopic Trillat procedure is a valuable and durable option for the treatment of recurrent anterior dislocations in older patients with chronic MIRCTs and conserved active shoulder motion.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Arthroscopic Anterior Shoulder Capsular Reconstruction Using Human Acellular Dermal Graft in Conjunction With Anatomic Glenoid Reconstruction

Capsular insufficiency of the shoulder associated with glenoid bone loss poses a major challenge to orthopaedic surgeons in the management of recurrent anterior instability. Multiple surgical techniques have been described in the literature with varying rates of success, and the majority of these are open techniques. We present a complete arthroscopic technique for anterior capsular reconstruction using acellular human dermal allograft patch in conjunction to an anatomic glenoid reconstruction using a distal tibial allograft in the lateral decubitus position. If the capsular insufficiency is determined irreparable after glenoid reconstruction, the acellular human dermal graft patch is prepared, inserted into the shoulder joint, and appropriately fixed using suture anchors on both glenoid and humerus, all through arthroscopic portals.

Management of off-track Hill-Sachs lesions in anterior glenohumeral instability

Bone loss has been identified as a risk factor for recurrent shoulder dislocations or failure after soft tissue repair. Although the range for "critical" bone loss is yet to be determined, glenoid and humeral bone defects should not be regarded as independent problems, but the interaction between them during shoulder motion should be evaluated as suggested by the glenoid track concept. The glenoid track concept is now widely accepted and considered essential for making decisions about surgery. Soft-tissue procedures usually work well in patients with on-track Hill-Sachs lesions but in off-track lesions do not. In this situation additional procedures should be performed.Different surgical options have been described to address off-track Hill-Sachs lesions, most commonly remplissage, Latarjet or free bone block procedures. Coracoid graft and free bone grafts convert the off-track Hill-Sachs lesion into on-track by lengthening the glenoid-track, whereas remplissage fill-in the humeral lesion so that it does not engage. In the setting of a Hill-Sachs lesion with little or no glenoid bone loss, remplissage has demonstrated satisfactory outcomes with a low complications and recurrence rate. Favorable results have been reported with glenoid bone grafting when managing isolated Hill-Sachs or bipolar lesions. Studies analyzing Latarjet and Eden-Hybinette procedures show that both procedures are safe and effective in the management of anterior glenohumeral instability. Attention should be paid to those patients with large bone defects not amenable to be restored with an isolated Latarjet that may be better addressed with an Eden-Hybinnete or adding a remplissage to the Latarjet procedure.

Posterior Glenoid Bone Loss and Instability: An Evidence-based Approach to Diagnosis and Management

Posterior glenohumeral instability is an underappreciated cause of disability that may necessitate surgical intervention to allow functional glenoid restoration. However, posterior glenoid bone abnormalities, when sufficiently severe, may contribute to persistent instability despite a well-performed capsulolabral repair. Recognition and understanding of these lesions is critical to both surgical decision making and execution of the surgical plan. Numerous procedures have been described to address posterior instability including recent developments in arthroscopic grafting techniques. The purpose of this article was to provide an evidence-based strategy for diagnosis and management of posterior shoulder instability and glenoid bone loss.

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.

Arthroscopic Anatomic Glenoid Reconstruction Hardware Removal

Recurrent shoulder instability is associated with bone loss. Distal tibial allograft reconstruction of the glenoid is an accepted technique for managing bone loss. Bone remodeling occurs within the first 2 years postoperatively. This can lead to prominent instrumentation, particularly anteriorly near the subscapularis tendon, causing pain and weakness. We provide a description of arthroscopic instrumentation removal for prominent anterior screws following anatomic glenoid reconstruction with distal tibial allograft.

Open Glenoid Augmentation With Scapular Spine Autograft for Recurrent Shoulder Instability: A Report of Two Cases

Optimal treatment for patients with significant glenoid bone loss after severe shoulder dislocation remains a topic of discussion, as there are many autograft and allograft techniques for glenoid augmentation. Several studies have identified scapular spine autograft to be a potential option for restoring glenohumeral stability, however, there is limited clinical data for this procedure. We present two cases in which patients suffered from anterior glenoid bone loss and recurrent shoulder instability who underwent open glenoid augmentation with scapular spine autograft. Both patients report a full return to activity with no functional limitations. Open glenoid augmentation with a scapular spine autograft is a viable option for patients with anterior glenoid bone loss and recurrent shoulder instability.

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.

Arthroscopic-Assisted Anterior Glenoid Reconstruction Using Nonrigid Fixation With Distal Tibia Osteochondral Allograft

Introduction:

Traumatic anterior glenohumeral instability events result in a capsulolabral (Bankart lesion) and/or osseous injury with subsequent attritional bone loss, particularly with recurrence. Up to 88% of patients with recurrent instability experience glenoid bone loss, which predisposes to future dislocations and subluxations, even with arthroscopic capsulolabral repair. The surgical management of glenoid bone loss includes a number of different techniques such as the Latarjet or coracoid transfer as well as other osseous and osteoarticular autografts and allografts. However, operative management of shoulder instability has increasingly shifted toward arthroscopic approaches with preservation of anatomy when possible.

Indications:

Arthroscopic-assisted allograft distal tibia bone block augmentation to the anterior glenoid is indicated for revision anterior glenohumeral instability procedures with anterior bone loss and in primary cases of anterior instability with critical bone loss.

Technique:

Our technique for nonrigid arthroscopic anterior glenoid reconstruction with allograft distal tibia and anterior labral repair is performed preferentially in the lateral position without necessitating patient repositioning. The preplanned tibial bone block is prepared on a back table prior to the arthroscopic procedure. After creation of portals and elevation of labral tissue, a guide and drill are used to introduce a retrograde reamer which is deployed to create a perpendicular edge for apposition of the allograft tibia. The bone block is then introduced through a rotator interval portal by pulling sutures retrograde through glenoid bone tunnels and is secured to the prepared surface medial to the liberated labrum. The articular surface of the graft and glenoid are aligned and suture-based fixation is used to compress the bone block against the native glenoid. The anterior labral tissue is then mobilized over the graft and repaired to the native glenoid when possible.

Description/Conclusion:

The benefits of allograft tibia augmentation for anterior instability with glenoid bone loss include an anatomic joint surface restoration including articular cartilage, lack of donor site morbidity, and a minimally invasive arthroscopic approach. When performed arthroscopically and with nonrigid fixation, this technique permits concurrent anterior labral repair and anatomic reconstruction, safe graft passage without necessity of a far medial portal, and expeditious return to function.

Morphometric and Biomechanical Comparison of the Scapular Spine and Coracoid Graft in Anterior Shoulder Instability

BACKGROUND

The scapular spine has been described as a relatively new bone graft alternative used in glenoid augmentation. The classic Latarjet procedure, which transfers the coracoid as a graft, is regarded as the gold standard. The comparison of these 2 techniques has not been fully reported.

PURPOSE

To compare the anatomic and biomechanical properties of glenoid augmentation using scapular spine graft or coracoid graft.

STUDY DESIGN

Controlled laboratory study.

METHODS

The study used 20 fresh-frozen human cadaveric shoulders. A 25% anterior glenoid defect was created, and the specimens were divided randomly to receive glenoid augmentation by scapular spine or coracoid grafts. For both procedures, the grafts were secured to the glenoid defect with 2 screws. Morphometric data, including the glenoid articular area, amount of restoration, and graft dimensions, were obtained. A biomechanical test was conducted in a direct-loading scenario. The construct stiffness, cyclic displacement, and ultimate failure of each specimen were collected.

RESULTS

No significant difference was found in glenoid articular restoration between the scapular spine group and the coracoid group (31% vs 33%, respectively; P = .311). Morphometric analysis indicated that coracoid grafts exhibited significantly greater thickness and height than scapular spine grafts. In biomechanical results, the scapular spine group exhibited significantly greater construct stiffness than the coracoid group (206.3 ± 58.8 vs 148.3 ± 76.0 N/mm, respectively; P = .023). The average failure load in the scapular spine group was not significantly higher than that in the coracoid group. No significant differences in cyclic displacement were found between the 2 techniques.

CONCLUSION

In a simulated 25% anterior glenoid bony defect, a scapular spine graft was comparable with the classic Latarjet procedure in restoring the glenoid articular dimension and exhibited superior construct stiffness in a cadaveric model.

CLINICAL RELEVANCE

The scapular spine may serve as an alternative graft choice in glenoid augmentation surgery considering the amount of articular restoration and initial fixation stability.

Glenoid bone augmentation: a contemporary and comprehensive systematic review of open procedures

Introduction

There is a trend towards arthroscopically treating shoulder instability with glenoid deficiency. Despite this, there remains the option for treatment through an open technique. Multiple bone augmentation options are available for recurrent anterior shoulder instability.

Objective

To provide a systematic review of recent studies for recurrent anterior shoulder instability necessitating glenoid bone augmentation specifically through open procedures using coracoid bone or free bone blocks [iliac crest bone autograft/allograft or distal tibia allograft (DTA)].

Methods

PubMed, Cochrane, EMBASE, and Google Scholar were searched for studies reporting open glenoid bone augmentation procedures with iliac crest, tibia, or coracoid bones within 10 years. Extracted data included study/patient characteristics, techniques, prior surgeries, prior dislocations, radiographic findings, range of motion (ROM), recurrent instability, patient-reported outcomes, and complications.

Results

92 met inclusion criteria (5693 total patients). Six were studies of iliac crest bone, four of DTA, and 84 using the coracoid bone. 29 studies measured postoperative arthritis showing no development or mild arthritis. 26 studies reported postoperative graft position. 62 studies reported ROM noting decline in internal/external rotation. 87 studies measured postoperative instability with low rates. Rowe Scores with noted improvement across 31/59 (52.5%) studies were seen. Common post operative complications included infection, hematoma, graft fracture, nerve injury, pain, and screw-related irritation.

Conclusion

Despite a trend towards arthroscopic management of recurrent anterior shoulder instability with glenoid deficiency, open procedures continue to provide satisfactory outcomes. Additionally, studies have demonstrated safe and efficacious use of free bone block graft options in the primary and revision setting.

Bony reconstruction after failed labral repair is associated with higher recurrence rates compared to primary bony reconstruction: a systematic review and meta-analysis of 1319 shoulders in studies with a minimum of 2-year follow-up

BACKGROUND

There is uncertainty with regard to the optimal revision procedure after failed labral repair for anterior shoulder instability. An overview of outcomes of these procedures with quantitative analysis is not available in literature. The aim of this review is (1) to compare recurrence rates after revision labral repair (RLR) and revision bony reconstruction (RBR), both following failed labral repair. In addition, (2) recurrence rates after RBR following failed labral repair and primary bony reconstruction (PBR) are compared to determine if a previous failed labral repair influences the outcomes of the bony reconstruction.

METHODS

Randomized controlled trials and cohort studies with a minimum follow-up of 2 years and reporting recurrence rates of (1) RBR following failed labral repair and PBR and/or (2) RLR following failed labral repair and RBR following failed labral repair were identified by searching PubMed, Embase/Ovid, Cochrane Database of Systematic Reviews/Wiley, Cochrane Central Register of Controlled Trials/Wiley, and Web of Science/Clarivate Analytics.

RESULTS

Thirteen studies met the inclusion criteria and comprised 1319 shoulders. Meta-analyses showed that RBR has a significantly higher recurrence rate than PBR (risk ratio [RR] 0.51, P < .008) but found no significant difference in the recurrence rates for RLR and RBR (RR 1.40, P < .49). Also, no significant differences were found between PBR and RBR in return to sport (RR 1.07, P < .41), revision surgery (RR 0.8, P < .44), and complications (RR 0.84, P < .53). Lastly, no significant differences between RLR and RBR for revision surgery (RR 3.33, P < .19) were found.

CONCLUSION

The findings of this meta-analyses show that (1) RBR does not demonstrate a significant difference in recurrence rates compared with RLR and that (2) RBR has a significantly higher recurrence rate than PBR.

The Addition of Remplissage to Free Bone Block Restores Translation and Stiffness Compared to Bone Block Alone or Latarjet in a Bipolar Bone Loss Model

PURPOSE

The purpose of this study was to compare glenohumeral stability following a Latarjet, a free bone block (FBB), and a FBB with remplissage for bipolar bone loss.

METHODS

Nine matched pairs of fresh frozen cadavers were tested in a custom biomechanical apparatus with rotation and progressive translational loading. The free bone block group consisted of a distal tibial allograft with an all-suture tape construct. The Latarjet group was performed with the native coracoid and two partially threaded cannulated screws. A bipolar bone loss model was created with 20% glenoid bone loss and an off-track Hill-Sachs lesion. Testing conditions included the 1) native state, 2) bipolar bone loss model, 3) Latarjet, 4) FBB with distal tibial allograft secured with cerclage sutures, and 5) FBB with remplissage. Each condition was tested for translation, humeral head apex shift, stiffness, and dislocation force.

RESULTS

There were no differences in translation, stiffness, or dislocation forced between the FBB alone and Latarjet groups. The FBB with remplissage group demonstrated the lowest anterior-inferior translation at 90° of ER, which was statistically significant compared to Latarjet 20N (P = .013) and compared to the FBB alone at 40N (P = .024) and 50N (P = .011). The FBB with remplissage group was significantly stiffer compared to FBB alone at 90° ER with approximately 60% change in stiffness (P = .028). The force required to dislocate the humeral head after treatment was highest in the FBB with remplissage group, which was statistically significant compared to the FBB alone (P = .003) and Latarjet groups (P = .018).

CONCLUSION

The addition of remplissage to a FBB restores translation and stiffness closer to the intact state compared to a FBB alone or Latarjet in a bipolar bone loss model with an off-track Hill-Sachs lesion. In this model, dislocation force significantly increased with the addition of remplissage to the FBB.

CLINICAL RELEVANCE

This biomechanical study provides evidence that Latarjet and FBB are both acceptable forms of treatment for bipolar bone loss, but stability can be enhanced with the addition of remplissage following glenoid reconstruction.

Editorial Commentary: Free Bone Block With Remplissage Provides Less Translation Than Free Bone Block Alone in Shoulder Instability Patients With Bipolar Bone Loss

It would stand to reason that, in shoulder instability patients with bipolar bone loss, the combination of a bone block procedure and a remplissage procedure would provide better results than each one alone. Why would this be the case? When performing these procedures in the lateral decubitus position for patients with critical bipolar bone loss, the humeral head is anteriorly and inferiorly subluxed. This is most likely due to the incompetent restraints when in traction. A bone block procedure alone doesn't necessarily reduce the glenohumeral center of rotation; rather, it increases the "jump distance," making it more difficult for the humerus to dislocate over the bone block. However, the remplissage procedure not only makes the Hill-Sachs lesion extra-articular and prevents the defect from levering out the humerus, but also seems to pull the humeral head posteriorly centering it in the glenoid. This provides a posterior tether to the humeral head while increasing the jump distance over the bone block even further. In the future, one can anticipate a significant increase in remplissage-augmented bone block procedures in patients with bipolar bone loss.

Trends in utilization and patient demographics for shoulder instability procedures from 2010 to 2019

BACKGROUND

Improved techniques and increased surgeon experience have optimized surgical care in patients with recurrent shoulder instability. Several techniques are used for surgical repair of shoulder instability, yet there are limited data on how utilization has changed over the past decade. The aim of this study was to assess trends in the utilization rate and patient demographic characteristics (age and sex) from 2010 to 2019 for 4 shoulder instability procedures: coracoid transfer/Latarjet procedure (LP), anterior bone block (ABB), open Bankart repair (OBR), and arthroscopic Bankart repair (ABR).

METHODS

We identified >87,000 patients using an all-payer claims database. The utilization rate was defined as the number of cases of a procedure divided by the total number of surgical cases for shoulder instability for any given year. Age was divided into 3 groups: <25 years, 25-35 years, and >35 years. Trends were reported in terms of the compounded annual growth rate (CAGR).

RESULTS

Although ABR was the most common shoulder instability procedure overall (91% utilization rate), the LP had the greatest increase in utilization from 2010 to 2019 (2.0% to 4.5%; CAGR, +9.8%). In comparison, the utilization of ABB procedures increased by 4.3% annually whereas that of OBR declined by 6.9% annually. The utilization of ABR showed minimal change. Notably, the LP was performed more frequently in younger patients over time. The percentage of patients aged < 25 years who underwent the LP increased from 30% to 41% from 2010 to 2019 (CAGR, +3.4%). There was a trend toward the performance of more LPs in men than in women (+1.2% vs. -3.5%, P < .05), although most cases (68%) were still performed in men.

CONCLUSION

ABR continues to account for most shoulder instability procedures. The LP had the greatest increase in the utilization rate from 2010 to 2019 and has now surpassed OBR in the utilization rate. ABB procedures are also being more frequently performed but only represent a minority of stabilization cases. During the course of the study period, a greater percentage of patients undergoing shoulder instability procedures were male individuals and were aged < 25 years.

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.

Arthroscopic Anterior Glenoid Reconstruction Using a Distal Tibial Allograft Positioned With an Intra-Articular Guide and Secured With Double-Button Fixation

Recurrent shoulder instability and its role in bone loss from the anterior glenoid is well recognized throughout the literature. This technique paper presents an all-arthroscopic technique that uses distal tibial allograft and double-button suture fixation to address anterior recurrent shoulder instability. With the patient in the lateral decubitus position, we use the posterior portal to position the double-barrel drill guide tangential to the face of the glenoid, while viewing through the anterosuperolateral portal. We then use the "bullets," which are made through two percutaneous posterior skin incisions of the double-barreled drill. This guide ensures parallel drill tunnels are created 5 mm medial to the glenoid articular surface and 1 cm apart, minimizing risk to the suprascapular nerve caused by a straying medial. We prepare a bone block from allograft distal tibia and place two drill holes to match those drilled in the glenoid vault. The allograft is then shuttled arthroscopically using looped passing wires. Once the final position is confirmed, a tensiometer is used to tension the graft in place. We then reattach the labrum to the native glenoid rim. Our technique creates a reproducible, anatomic, glenoid surface reconstruction for anterior glenoid bone loss in recurrent 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.

Arthroscopic Technique for Distal Tibial Allograft Bone Augmentation With Suture Anchor Fixation for Anterior Shoulder Instability

Recurrent instability associated with glenoid bone loss is a commonly encountered problem after anterior shoulder dislocation. Surgical management with bony augmentation can be achieved with several allograft or autograft options. Fixation strategies also vary, including screw, suture button, or suture anchor fixation. Concerns exist regarding screw fixation because of the technical difficulty of a medial portal establishment, as well as the potential for graft osteolysis. Suture button fixation for osteochondral graft fixation has been previously described. However, no description of graft fixation using suture anchors exists. We describe an arthroscopic technique for glenoid augmentation using distal tibial allograft with suture anchor fixation.

Fixation Type Does not Affect the Learning Curve and Short-Term Radiographic Outcomes for Arthroscopic Anatomic Glenoid Reconstruction with Distal Tibia Allograft

Purpose

The purpose of this study was to compare the learning curves and radiographic variables between screw and suture button fixation of the allograft for surgeons learning the all-arthroscopic anatomic glenoid reconstruction (AAGR) technique for anterior shoulder instability. We compared the surgical times of these two fixation techniques, as well as the graft placement in the vertical and medial-lateral directions.

Methods

This was a retrospective review of patients who underwent AAGR for recurrent anterior shoulder instability. Start and end times were recorded for each procedure, and learning was assessed through the change in operative time over successive surgeries and by variability of operative time. Graft placement, in terms of vertical positioning, medial-lateral step formation, and obliquity of fixation (alpha angle), was evaluated using 3-dimensional CT scans at approximately 6 months postoperation.

Results

A total of 43 patients were included in our study. Twenty-seven had screw fixation, and 16 had suture button fixation. The surgical duration of the button fixation technique was comparable to that of screw fixation (P = .72), with no significant difference in the variability of surgical time in either cohort (P > .05). Both groups showed similarly optimal vertical positioning of the graft onto the lower third of the glenoid (P = .89). Desired obliquity of graft fixation was identified more frequently with button fixation (P < .001). Both fixation methods provided clinically acceptable medial-lateral step formations, with suture-button fixation being significantly larger (P = .03).

Conclusions

Suture button fixation of the allograft is a potential alternative to screw fixation for the management of glenoid bone loss in recurrent anterior shoulder instability. The results of this study show that this method has a comparable learning curve, with a similar surgical duration, while not compromising the optimal accuracy of vertical and medial-lateral placement of the graft and achieves a superior alpha angle of fixation.

Level of Evidence

Level III, retrospective cohort study.

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.

Free bone grafting improves clinical outcomes in anterior shoulder instability with bone defect: a systematic review and meta-analysis of studies with a minimum of 1-year follow-up

BACKGROUND

Evidence on the efficacy and safety of the free bone grafting in treating anterior shoulder instability is limited. The purpose of this study was to systematically evaluate the clinical and imaging results of free bone grafting in treating anterior shoulder instability with glenoid bone defect and to explore the incidence of complications in clinically relevant subgroups.

METHODS

This systematic review was conducted per PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The PubMed, Embase, and Cochrane Library databases were searched up to January 29, 2021, for studies that had reported on free bone grafting in treating anterior shoulder instability with glenoid bone defect with a minimum of 1-year follow-up. Two researchers independently screened studies and extracted data. A random-effects model was used to pool data on clinical function scores, imaging results, and incidence of complications (recurrent instability and non-instability-related complications). Meta-regression analysis was used to evaluate the incidence of complications in different subgroups and investigate the sources of heterogeneity.

RESULTS

A total of 29 studies were included in the meta-analysis, comprising 840 patients (845 shoulders) with average ages ranging from 21 to 34.6 years. Compared with preoperatively, free bone grafting increased the postoperative Rowe score, American Shoulder and Elbow Surgeons score, Constant score, Subjective Shoulder Value, and Oxford Shoulder Instability Score by 53.16, 31.80, 20.81, 38.63, and 4.07 points, respectively, and reduced the visual analog scale pain score by 3 points on average. During the postoperative follow-up period, the rates of return to sport and return to preoperative levels were 84.2% and 73.1%, respectively. The imaging results showed that the free bone healing rate was 98.9% and the incidence of osteoarthritis was 10.9%. The incidence rates of recurrent instability and non-instability-related complications were 3.4% and 5.6%, respectively. Meta-regression analysis showed no evidence of effect modification by the year, follow-up time, proportion of male patients, autograft or allograft, and arthroscopy or open surgery on the incidence of complications. Subgroup analysis showed that the incidence rates of recurrent instability for open surgery, arthroscopy, allograft, autograft, Latarjet revision, and non-bone block revision were 4.1%, 2.3%, 1.5%, 4.4%, 10.3%, and 3.5%, respectively.

CONCLUSION

The application of free bone grafting in treating anterior shoulder instability with glenoid bone defect can effectively improve shoulder joint function and is associated with a high return-to-sport rate and a low overall recurrence rate, but there were some differences in the complications of recurrent instability and non-instability-related complications among the subgroups. Given that these results need to be confirmed via head-to-head comparisons, we recommend that future clinical and biomechanical studies focus on comparing and investigating the advantages and disadvantages of different surgical approaches, thus providing a basis for orthopedic surgeons to make reliable choices.

[Rebalancing theory of shoulder stability mechanism for the diseases related to the shoulder instability and dysfunction of motion]

Objective

To introduce a new theory of shoulder stability mechanism, rebalancing theory, and clinical application of this new theory for the shoulder instability and dysfunction of motion.

Methods

Through extensive review of the literature related to shoulder instability and dysfunction of the motion in recent years, combined with our clinical practice experience, the internal relation between passive stability mechanism and dynamic stability mechanism were summarized.

Results

Rebalancing theory of shoulder stability mechanism is addressed, namely, when the shoulder stability mechanism is destructive, the stability of the shoulder can be restored by the rebalance between dynamic stability mechanism and passive stability mechanism. When dynamic stability is out of balance, dynamic stability can be restored by rebalancing the different parts of dynamic stability mechanism or to strengthen the passive stability mechanism. When passive stability mechanism is out of balance, passive stability can be restored by rebalancing the soft tissue and bone of the shoulder.

Conclusion

Rebalancing theory of shoulder stability mechanism could make a understanding the occurrence, development, and prognosis of shoulder instability and dysfunction from a comprehensive and dynamic view and guide the treatment effectively.

Comparison of the Coracoid, Distal Clavicle, and Scapular Spine for Autograft Augmentation of Glenoid Bone Loss: A Radiologic and Cadaveric Assessment

BACKGROUND

Glenohumeral instability caused by bone loss requires adequate bony restoration for successful surgical stabilization. Coracoid transfer has been the gold standard bone graft; however, it has high complication rates. Alternative autologous free bone grafts, which include the distal clavicle and scapular spine, have been suggested.

STUDY DESIGN

Controlled laboratory study.

PURPOSE

The purpose of this study was to determine the percentage of glenoid bone loss (GBL) restored via coracoid, distal clavicle, and scapular spine bone grafts using a patient cohort and a cadaveric evaluation.

METHODS

Autologous bone graft dimensions from a traditional Latarjet, congruent arc Latarjet, distal clavicle, and scapular spine were measured in a 2-part study using 52 computed tomography (CT) scans and 10 unmatched cadaveric specimens. The amount of GBL restored using each graft was calculated by comparing the graft thickness with the glenoid diameter.

RESULTS

Using CT measurements, we found the mean percentage of glenoid restoration for each graft was 49.5% ± 6.7% (traditional Latarjet), 45.1% ± 4.9% (congruent arc Latarjet), 42.2% ± 7.7% (distal clavicle), and 26.2% ± 8.1% (scapular spine). Using cadaveric measurements, we found the mean percentage of glenoid restoration for each graft was 40.2% ± 5.0% (traditional Latarjet), 53.4% ± 4.7% (congruent arc Latarjet), 45.6% ± 8.4% (distal clavicle), and 28.2% ± 7.7% (scapular spine). With 10% GBL, 100% of the coracoid and distal clavicle grafts, as well as 88% of scapular spine grafts, could restore the defect (P < .001). With 20% GBL, 100% of the coracoid and distal clavicle grafts but only 66% of scapular spine grafts could restore the defect (P < .001). With 30% GBL, 100% of coracoid grafts, 98% of distal clavicle grafts, and 28% of scapular spine grafts could restore the defect (P < .001). With 40% GBL, a significant difference was identified (P = .001), as most coracoid grafts still provided adequate restoration (congruent arc Latarjet, 82.7%; traditional Latarjet, 76.9%), but distal clavicle grafts were markedly reduced, with only 51.9% of grafts maintaining sufficient dimensions.

CONCLUSIONS

The coracoid and distal clavicle grafts reliably restored up to 30% GBL in nearly all patients. The coracoid was the only graft that could reliably restore up to 40% GBL.

CLINICAL RELEVANCE

With "subcritical" GBL (>13.5%), all autologous bone grafts can be used to adequately restore the bony defect. However, with "critical" GBL (≥20%), only the coracoid and distal clavicle can reliably restore the bony defect.

Arthroscopic Bone Block Cerclage Technique Using a Tricortical Scapular Spine Autograft for Glenoid Reconstruction in Patients With Anterior Shoulder Instability

In the treatment of anterior shoulder instability with glenoid bone loss, free bone graft transfers have proven to be a viable anatomic alternative to the commonly performed, nonanatomic Latarjet procedure. Implant-free fixation of the free bone grafts, in particular, has rendered excellent short- and long-term results. However, a drawback remains the source of the graft. We describe an arthroscopic bone block cerclage technique using a tricortical scapular spine autograft, which provides an anatomic arthroscopic glenoid reconstruction with the combined benefit of sparing the subscapularis, metal-free fixation, and intraregional donor site for autograft harvesting.

Anterior Shoulder Instability Part II-Latarjet, Remplissage, and Glenoid Bone-Grafting-An International Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements via a modified Delphi process on the Latarjet procedure, remplissage, and glenoid-bone grafting for anterior shoulder instability.

METHODS

A consensus process on the treatment utilizing a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability.

RESULTS

The technical approaches identified in the statements on the Latarjet procedure and glenoid bone-graft were that a subscapularis split approach should be utilized, and that it is unclear whether a capsular repair is routinely required. Furthermore, despite similar indications, glenoid bone-grafting may be preferred over the Latarjet in patients with bone-loss greater than can be treated with a coracoid graft, and in cases of surgeon preference, failed prior Latarjet or glenoid bone-grafting procedure, and epilepsy. In contrast, the primary indications for a remplissage procedure was either an off-track or engaging Hill-Sachs lesion without severe glenoid bone loss. Additionally, in contrast to the bone-block procedure, complications following remplissage are rare, and loss of shoulder external rotation can be minimized by performing the tenodesis via the safe-zone and not over medializing the fixation.

CONCLUSION

Overall, 89% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were the prognostic factors that are important to consider in those undergoing a glenoid bone-grafting procedure including age, activity level, Hill-Sachs Lesion, extent of glenoid bone-loss, hyperlaxity, prior surgeries, and arthritic changes. Furthermore, there was unanimous agreement that it is unclear whether a capsular repair is routinely required with a glenoid bone graft, but it may be beneficial in some cases. There was no unanimous agreement on any aspect related to the Latarjet procedure or Remplissage.

LEVEL OF EVIDENCE

Level V, expert opinion.

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.

Treatment of Failed Latarjet With Arthroscopic Anatomic Glenoid Reconstruction

PURPOSE

Various methods have been described for the treatment of anterior shoulder instability with glenoid bone loss. The incidence of recurrent dislocations following surgical intervention is high and, therefore, necessitates a reliable and replicable revision procedure. The purpose of this Technical Note is to describe a method of arthroscopic anatomic glenoid reconstruction using a distal tibial allograft and screw fixation in the setting of a failed Latarjet procedure with significant glenoid bone loss.

METHODS

We describe in detail patient positioning, portal placement, steps of the diagnostic arthroscopy, and graft preparation using imaging and a detailed intraoperative arthroscopic technique.

LEVEL OF EVIDENCE

Level 1, Shoulder; Level 2, Instability.