Radiographic Analysis of Glenoid Size and Shape After Arthroscopic Coracoid Autograft Versus Distal Tibial Allograft in the Treatment of Anterior Shoulder Instability

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.

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.

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.

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.

Arthroscopic Latarjet Versus Arthroscopic Free Bone Block Procedures for Anterior Shoulder Instability: A Proportional Meta-analysis Comparing Recurrence, Complication, and Reoperation Rates

BACKGROUND

Several arthroscopic glenoid bone augmentation techniques have been introduced to treat patients affected by anterior shoulder instability associated with critical bone loss. The efficacy of the different arthroscopic bony procedures has not been compared yet.

PURPOSE

To compare the recurrence, complication, and reoperation rates of the arthroscopic Latarjet (AL) and arthroscopic free bone block (ABB) procedures for anterior shoulder instability.

STUDY DESIGN

Meta-analysis and systematic review; Level of evidence, 4.

METHODS

A systematic search was conducted in MEDLINE/PubMed, Web of Science, and Embase to identify clinical studies reporting the outcomes of the AL and ABB procedures. The following search phrases were used: "Arthroscopic" AND "Bone Block" OR "Bone Graft," and "Arthroscopic" AND "Glenoid Augmentation" OR "Glenoid Reconstruction," and "Arthroscopic" AND "Latarjet" OR "Coracoid Graft" OR "Coracoid Transfer." Exclusion criteria were <24 months of minimum follow-up, sample size <10 cases, revision after previous glenoid bone grafting, epilepsy, and multidirectional instability. Data regarding the study design, patient characteristics, surgical technique, and outcomes were extracted and analyzed. A proportional meta-analysis was conducted to compare the complication, recurrence, and reoperation rates between the 2 groups. Multiple subgroup analyses were performed to analyze the incidence of each complication and assess the weight of different fixation methods (in the whole cohort) or different graft types (in the ABB group). The modified Coleman Methodology Score was used to assess the risk of bias.

RESULTS

Of 5010 potentially relevant studies, 18 studies regarding the AL procedure (908 cases) and 15 studies regarding the ABB procedure (469 cases) were included. The 2 groups were comparable in age (P = .07), sex (P = .14), glenoid bone loss (P = .14), number of preoperative dislocations (P = .62), proportion of primary and revision procedures (P = .95), length of follow-up (P = .81), modified Coleman Methodology Score (P = .21), and level of evidence (P = .49). There was no difference in the recurrence (P = .88), reoperation (P = .79), and complication (P = .08) rates. The subgroup analyses showed a higher rate of hardware-related complications for screw fixation compared with flexible fixation (P = .01).

CONCLUSION

The AL and ABB procedures had similar recurrence, reoperation, and complication rates. Screw fixation of the bone graft was related to an increased risk of complications compared with flexible fixation.

REGISTRATION

CRD42022368153 (PROSPERO).

Clinical and radiographic outcomes of primary vs. revision arthroscopic anatomic glenoid reconstruction with distal tibial allograft for anterior shoulder instability with bone loss

BACKGROUND

The purpose of this study was to assess the clinical and radiographic outcomes of arthroscopic anatomic glenoid reconstruction (AAGR) used for primary vs. revision surgery for addressing anterior shoulder instability with bone loss.

METHODS

We performed a retrospective review on consecutive patients who underwent AAGR from 2012 to 2020. Patients who received AAGR for anterior shoulder instability with bone loss and had a minimum follow-up of 2 years were included. Exclusion criteria included patients with incomplete primary patient-reported outcome scores (PROs), multidirectional instability, glenoid fracture, nonrigid fixation and concomitant humeral avulsion of the glenohumeral ligament, or rotator cuff repair. Our primary outcome was measured using the Western Ontario Shoulder Instability Index (WOSI) scores. Secondary outcomes included postoperative Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) scores, complications, recurrence of instability and computed tomographic (CT) evaluation of graft position, resorption, and healing.

RESULTS

There were 73 patients (52 primary and 21 revision) finally included. Both groups had comparable demographics and preoperative WOSI and DASH scores. The primary group had significantly better postoperative WOSI and DASH scores at final follow-up when compared to the revision group (WOSI: 21.0 vs. 33.8, P = .019; DASH: 7.3 vs. 17.2, P = .001). The primary group also showed significantly better WOSI scores than the revision group at the 6-month, 1-year, and 2-year time points (P = .029, .022, and .003, respectively). The overall complication rate was 9.6% (5 of 52) in the primary group and 23.8% (5 of 21) in the revision group. Both groups showed good graft healing and placement in the anterior-to-posterior and mediolateral orientation and had a similar rate of graft resorption and remodeling. There was no difference between the groups in the remainder of the CT measurements.

CONCLUSION

Functional outcome scores and stiffness were significantly worse in patients undergoing an AAGR procedure after a failed instability surgery when compared with patients undergoing primary AAGR. There were no differences in postoperative recurrence of instability or radiographic outcomes. As a result, AAGR should be considered as a primary treatment option within current treatment algorithms for shoulder instability.

Clinical Outcomes and Graft Resorption After Metal-Free Bone Block Suture Tape Cerclage Fixation for Recurrent Anterior Shoulder Instability: A Computed Tomography Analysis

BACKGROUND

Glenoid reconstruction with a bone block for anterior glenoid bone loss (GBL) has shown excellent outcomes. However, fixation techniques that require metal implants are associated with metal-related complications and bone graft resorption.

HYPOTHESIS

Arthroscopic glenoid reconstruction using a tricortical iliac crest bone graft (ICBG) and metal-free suture tape cerclage fixation can safely and effectively restore the glenoid surface area in patients with recurrent anterior shoulder instability and anterior GBL.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Adult patients (≥18 years) of both sexes with recurrent anterior shoulder instability and anterior GBL ≥15% were enrolled. These patients underwent arthroscopic glenoid reconstruction with ICBGs and metal-free suture tape cerclage fixation. The effectiveness and clinical outcomes with this technique were evaluated at 24 months using functional scores. Resorption of the graft articular surface was assessed by computed tomography, with the graft surface divided into 6 square areas aligned in 2 columns. Descriptive analysis was conducted.

RESULTS

A total of 23 consecutive patients met inclusion criteria (22 male, 1 female; mean age, 30.5 ± 7.9 years). The mean preoperative GBL was 19.7% ± 3.4%, and there were 15 allograft and 8 autograft ICBGs. All patients exhibited graft union at 3 months. The median follow-up was 38.5 months (interquartile range, 24-45 months). The Western Ontario Shoulder Instability Index, Rowe, Constant-Murley, and Subjective Shoulder Value scores improved from preoperatively (35.1%, 24.8, 83.1, and 30.9, respectively) to postoperatively (84.7%, 91.1, 96.0, and 90.9, respectively) (P < .001). No differences in clinical scores were observed between the graft types. One surgical wound infection was reported, and 2 patients (8.7% [95% CI, 2.4%-26.8%]) required a reoperation. The mean overall glenoid surface area increased from 80.3% ± 3.5% to 117.0% ± 8.3% immediately after surgery before subsequently reducing to 98.7% ± 6.2% and 95.0% ± 5.7% at 12 and 24 months, respectively (P < .001). The mean graft resorption rate was 18.1% ± 7.9% in the inner column and 80.3% ± 22.4% in the outer column. Additionally, 3 patients treated with an allograft (20.0% [95% CI, 7.1%-45.2%]), including the 2 with clinical failures, exhibited complete graft resorption at the last follow-up.

CONCLUSION

Arthroscopic glenoid reconstruction using an ICBG and metal-free suture tape cerclage fixation was safe and effective, yielding excellent clinical outcomes. Resorption of the graft articular surface predominantly affected the nonloaded areas beyond the best-fit circle perimeter.

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.

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.

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.

Distal Clavicle Autograft Versus Traditional and Congruent Arc Latarjet Procedures: A Comparison of Surface Area and Glenoid Apposition With 3-Dimensional Computed Tomography and 3-Dimensional Magnetic Resonance Imaging

BACKGROUND

Limited studies have compared graft-glenoid apposition and glenoid augmentation area between the Latarjet procedure and distal clavicle graft in glenohumeral stabilization. Additionally, preoperative planning is typically performed using computed tomography (CT), and few studies have used 3-dimensional (3D) magnetic resonance imaging (MRI) reformations to assess graft dimensions.

PURPOSE

The purpose of this study was 2-fold: (1) to compare bony apposition, glenoid augmentation, and graft width among coracoid and distal clavicle bony augmentation techniques and (2) to determine the viability of 3D MRI to assess bone graft dimensions.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 24 patients with recurrent glenohumeral instability and bone loss were included in this study. 3D CT and 3D MRI reformations were utilized to measure pertinent dimensions for 5 orientations of coracoid and distal clavicle autografts: (1) standard Latarjet procedure (SLJ), (2) congruent arc Latarjet procedure (CLJ), (3) distal clavicle attached by its posterior surface (DCP), (4) distal clavicle attached by its inferior surface (DCI), and (5) distal clavicle attached by its resected end (DCR). Glenoid augmentation was defined as the graft surface area contributing to the glenoid. Bone-on-bone apposition was defined as the graft-glenoid contact area for bone healing potential, and graft width was pertinent for fixation technique. Glenoid bone loss ranged from 0% to 34%. Paired t tests were used to compare graft sizes between patients and compare 3D CT versus 3D MRI measurements.

RESULTS

The CLJ had the largest graft surface area (mean, 318.41 ± 74.44 mm²), while the SLJ displayed the most bone-on-bone apposition (mean, 318.41 ± 74.44 mm²). The DCI had the largest graft width (mean, 20.62 ± 3.93 mm). Paired t tests revealed no significant differences between the Latarjet techniques, whereas distal clavicle grafts varied significantly with orientation. All 3D CT and 3D MRI measurements were within 1 mm of each other, and only 2 demonstrated a statistically significant difference (coracoid width: 13.03 vs 13.98 mm, respectively [P = .010]; distal clavicle thickness: 9.69 vs 10.77 mm, respectively [P = .002]). 3D CT and 3D MRI measurements demonstrated a strong positive correlation (r > 0.6 and P < .001 for all dimensions).

CONCLUSION

Glenoid augmentation, bony apposition, and graft width varied with coracoid or distal clavicle graft type and orientation. Differences between 3D CT and 3D MRI were small and likely not clinically significant.

CLINICAL RELEVANCE

3D MRI is a viable method for preoperative planning and graft selection in glenoid bone loss.

Radiological and Histological Analyses of Nonrigid Versus Rigid Fixation for Free Bone Block Procedures in a Rabbit Model of Glenoid Defects

BACKGROUND

Nonrigid fixation techniques have been recently introduced in free bone block (FBB) procedures to treat substantial glenoid bone loss in patients with anterior shoulder instability. However, the radiological and histological effectiveness of nonrigid fixation versus conventional rigid fixation have not been comprehensively understood in vivo.

PURPOSE

To (1) explore the radiological and histological characteristics of nonrigid fixation for FBB procedures in a rabbit model of glenoid defects and (2) further compare them with those of conventional rigid fixation.

STUDY DESIGN

Controlled laboratory study.

METHODS

Unilateral shoulder glenoid defects were created in 36 mature New Zealand White rabbits, of which 24 underwent FBB procedures using allogenic iliac crest bone and were randomly divided into rigid fixation (RF) and nonrigid fixation (N-RF) groups, with the remaining divided into 2 control groups: 6 with sham surgery for glenoid defects (GD group) and 6 native glenoids (normal group). In the RF and N-RF groups, 6 rabbits were sacrificed at 6 or 12 weeks postoperatively for radiological and histological analyses of the reconstructed glenoid, and all rabbits in the GD and normal groups were sacrificed at 12 weeks. The radiological glenoid morphology was evaluated via micro-computed tomography. Moreover, the graft-glenoid healing and graft remodeling processes were determined using histological staining.

RESULTS

At 6 weeks, both the N-RF and RF groups had similarly improved radiological axial radian and en face area of the glenoid compared with the GD group, but the N-RF group showed superiority in restoration of the glenoid radian and area compared with the RF group at 12 weeks, with the native glenoid as the baseline. Histologically, the bone graft in both groups was substantively integrated into the deficient glenoid neck at 6 and 12 weeks, showing similar osseous healing processes at the graft-glenoid junction. Moreover, the bone graft histologically presented similar regenerated vascular density, total graft bone, and integrated graft bone in both groups. In contrast, the N-RF group had a different remodeling profile on radiological and histological analyses regarding regional bone resorption, mineralization, and fibrous tissue replacement during osseointegration.

CONCLUSION

Compared with rigid fixation, nonrigid fixation resulted in superior reconstructed glenoid morphology radiologically and similar graft-glenoid osseous healing histologically, showing different graft remodeling profiles of regional bone resorption, mineralization, and fibrous tissue replacement.

CLINICAL RELEVANCE

The nonrigid fixation technique can be feasible for FBB procedures to treat glenoid bone loss in anterior shoulder instability. More clinical evidence is required to determine its pros and cons compared with conventional rigid fixation.

Clinical and Radiological Outcomes in Patients With Anterior Shoulder Instability and Glenoid Bone Loss after Arthroscopic Free Bone Block Combined With Dynamic Anterior Stabilization

BACKGROUND

As an alternative to the Latarjet procedure, the arthroscopic free bone block (FBB) procedure combined with dynamic anterior stabilization (DAS) has been recently proposed to provide both glenoid augmentation and a tendon sling effect for treating anterior shoulder instability (ASI) with glenoid bone loss.

PURPOSE

To evaluate the clinical and radiological outcomes of FBB-DAS for ASI with glenoid bone loss.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients who underwent arthroscopic FBB-DAS for ASI with >15% glenoid bone loss between February 2017 and March 2020 were screened and enrolled in this study. Clinical outcome measures were assessed preoperatively and at a minimum 2-year follow-up, including recurrence, complications, shoulder functional scores, range of motion, and return to sports. Postoperative computed tomography and magnetic resonance imaging were also performed.

RESULTS

Of a total of 65 patients with a mean follow-up of 46.1 ± 13.1 months, no patients experienced a recurrent dislocation or subluxation postoperatively, while 2 had a positive anterior apprehension test (3.1%). Additionally, 2 patients (3.1%) experienced complications of hematoma and shoulder stiffness, respectively. The mean visual analog scale score, American Shoulder and Elbow Surgeons score, Rowe score, and Oxford Shoulder Instability Score all improved significantly from 3.2 ± 2.4, 75.0 ± 18.9, 43.6 ± 27.3, and 33.8 ± 9.0 preoperatively to 1.3 ± 0.8, 95.1 ± 8.0, 95.5 ± 7.8, and 14.8 ± 3.5 at final follow-up, respectively (all P < .001). No difference was detected in range of motion except for 8.1° and 7.5° external rotation limitations in adduction and abduction, respectively. There were 62 patients (95.4%) who returned to sports, and 54 patients (83.1%) returned to the preinjury level. The transferred biceps tendon was intact in all 59 patients who completed radiological examination at the latest follow-up. Good bone healing was achieved in 98.3% of patients, and the glenoid bone defect decreased from 18.1% to 4.9%. Osseous and labral glenoids were significantly enlarged in width and depth on the latest magnetic resonance imaging (all P < .001).

CONCLUSION

Arthroscopic FBB-DAS provided satisfactory clinical and radiological outcomes for ASI with glenoid bone loss. Despite slight external rotation restrictions, it achieved low recurrence and complication rates, excellent shoulder functional scores, a high return-to-sports rate, and favorable graft healing and remodeling.

High resorption rates following glenoid augmentation procedures do not seem to lead to higher recurrence rates or worse clinical outcomes: a systematic review and meta-analysis

PURPOSE

Bone augmentation techniques show a relatively high complication rate, which might be due to graft non-union and resorption. It is unclear which augmentation techniques demonstrate the highest amount of non-union and resorption and whether this leads to worse clinical or functional outcomes. Therefore, the aim of this review was (i) to compare non-union and resorption rates between surgical approaches, procedures, graft types, donor sites and fixation methods regarding clinical and functional outcomes and (ii) determine whether high non-union or resorption rates lead to less favorable clinical or functional outcomes.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements were followed. PubMed, EMBASE (Ovid) and Cochrane Library were searched on December 15th 2021 for studies examining bone graft non-union or resorption using radiograph or CT following glenoid augmentation to treat anterior shoulder dislocation.

RESULTS

The search resulted in 103 inclusions, comprising 5,128 glenoid augmentations. When comparing pooled proportions of bony union, graft fracture rate, hardware failure rate, recurrence rate, return to sports and Rowe score, most results were similar between approaches, procedures, graft types, donor sites and fixation methods. High resorption rates were seen for allograft augmentation (74.3; 95% CI: 39.8-92.7) compared to autograft augmentation (15.5; 95% CI 10.1-23.2), but this was not associated with higher recurrence rates or worse clinical outcomes. Meta-analyses (8 studies; 494 patients) demonstrated no difference in incomplete and complete non-union rates between arthroscopic and open procedures; however, both analyses showed substantial heterogeneity. Higher partial resorption rates were observed on CT (48.0; 95% CI 43.3-52.7) compared to radiograph (14.1; 95% CI 10.9-18.1). Three studies comprising 267 shoulders demonstrated a higher rate of non-union and recurrence in smokers, whereas one study comprising 38 shoulders did not.

CONCLUSION

Non-union and resorption rates were similar among procedures, grafts and fixation methods. Higher resorption rates were observed in allografts, but this was not associated with higher recurrence rates or worse clinical outcomes. Pooling data demonstrated substantial heterogeneity and definitions varied among studies, warranting more standardized measuring.

LEVEL OF EVIDENCE

IV.

Influence of Graft Positioning during the Latarjet Procedure on Shoulder Stability and Articular Contact Pressure: Computational Analysis of the Bone Block Effect

The Latarjet procedure is the most popular surgical procedure to treat anterior glenohumeral (GH) instability in the presence of large anterior glenoid bone defects. Even though the placement of the bone graft has a considerable influence on its efficacy, no clear indications exist for the best graft position. The aim of this study was to investigate the influence of the medial-lateral positioning of the bone graft on the contact mechanics and GH stability due to the bone block effect. Four finite element (FE) models of a GH joint, with a 20% glenoid bone defect, treated by the Latarjet procedure were developed. The FE models differed in the medial-lateral positioning of the bone graft, ranging from a flush position to a 4.5 mm lateral position with respect to the flush position. All graft placement options were evaluated for two separate shoulder positions. Anterior GH instability was simulated by translating the humeral head in the anterior direction, under a permanent compressive force, until the peak translation force was reached. Joint stability was computed as the ratio between the shear and the compressive components of the force. The lateralization of the bone graft increased GH stability due to the bone block effect after a 3 mm lateralization with respect to the flush position. The increase in GH stability was associated with a concerning increase in peak contact pressure due to the incongruous contact between the articulating surfaces. The sensitivity of the contact pressures to the medial-lateral positioning of the bone graft suggests a trade-off between GH stability due to the bone block effect and the risk of osteoarthritis, especially considering that an accurate and consistent placement of the bone graft is difficult in vivo.

How to Fashion the Bone Block for Reconstruction of the Glenoid in Anterior and Posterior Instability

BACKGROUND

Glenoid restoration techniques to address glenohumeral instability-induced anterior and posterior glenoid bone loss (AGBL and PGBL) often require reconstruction, but best-fit bone block (BFBB) modeling has not been developed.

PURPOSE

To provide glenoid bony reconstruction models for anterior and posterior instability of the shoulder using a bone loss instability cohort with high-fidelity 3-dimensional (3D) imaging.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We reviewed consecutive patients indicated for operative stabilization who had posterior glenohumeral instability and suspected GBL who underwent 2-dimensional (2D) computed tomography (CT). Patients were matched by sex, laterality, and age to patients who underwent operative stabilization of anterior glenohumeral instability. Mimics software was used to convert all 2D CT scans into 3D models of the scapula. A BFBB model was designed to digitally reconstruct GBL and was used to predict the amount, anatomic configuration, and fixation configuration of bony reconstruction required in AGBL and PGBL.

RESULTS

The study included 30 patients with posterior instability and 30 patients with anterior instability; the participants' mean ± SD age was 28.8 ± 8.15 years (range, 16.0-51.0 years). Mean surface area of AGBL was 24.9% ± 7.7% (range, 14.7%-39.1%). Mean BFBB dimensions to reconstruct the anterior glenoid were determined to be a superior-inferior length of 23.9 ± 4.2 mm, anterior-posterior width of 6.4 ± 2.4 mm, and height of 1 cm. Mean angle of AGBL bone block interface relative to glenoid to reconstruct the native concavity was 79.4°± 5.9°. For PGBL, the mean surface area was 9.2% ± 5.6% (range, 3.0%-26.3%). Mean BFBB dimensions to reconstruct the posterior glenoid were a superior-inferior length of 21.9 ± 3.4 mm, width of 4.5 ± 2.3 mm, and height of 1 cm. The mean angle of PGBL bone block interface relative to the glenoid to reconstruct the native concavity was 38.6°± 14.3°. Orientation relative to the vertical glenoid axis was 77.2°± 13.8° in anterior reconstructions versus 105.9°± 10.9° in posterior reconstructions.

CONCLUSION

Patients with anterior instability required a more rectangular BFBB with a bone block-glenoid interface angle of 79°, whereas patients with posterior instability required a more trapezoidal, obtusely oriented BFBB with a bone block-glenoid interface angle of 39°. BFBBs for either AGBL or PGBL can be effectively designed, and their size and/or shape can be predicted based on approximate percentage of GBL.

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.

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.

Structural and Functional Results of Subscapularis and Conjoint Tendon After Latarjet Procedure at 8-Year Average Follow-up

BACKGROUND

The Latarjet procedure involves initial dissection through a longitudinal split of the subscapularis tendon with only a final partial closure to accommodate the transferred coracoid bone. Furthermore, by transferring the coracoid bone block to the anterior glenoid, the surgeon completely alters the resting and dynamic route of the attached conjoint tendon. The eventual structural and functional integrity of the subscapularis and conjoint tendons is currently unknown.

PURPOSE

To examine the structural and functional integrity of the subscapularis and the conjoint tendon after the Latarjet procedure at an 8-year average follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty patients with anterior shoulder instability at a mean age of 30 years (range, 19-50 years) underwent the open Latarjet procedure. Clinical examination at the final follow-up included quantitative isometric measurement of abduction and internal rotation strength compared with the nonoperative side. Patients were assessed via radiograph examination and preoperative computed tomography. Final position and healing of the transferred coracoid bone block were evaluated using standard radiographs. At follow-up, the subscapularis and conjoint tendon were evaluated via magnetic resonance imaging (MRI) with metal artifact reduction techniques and via ultrasound.

RESULTS

Nineteen of the 20 shoulders remained stable at the final follow-up; there was 1 redislocation (5%) after 14 months. The mean Rowe score was 83 points (SD, 17.9 points), the mean Constant score was 85 points (SD, 8.1 points), and the Subjective Shoulder Value was 80% (SD, 18%). The mean abduction strength of the operative shoulder was 7.41 ± 2.06 kg compared with 8.33 ± 2.53 kg for the nonoperative side (P = .02). The mean internal rotation strength at 0° for the operative shoulder was 8.82 ± 3.47 kg compared with 9.06 ± 3.01 kg for the nonoperative side (P = .36). The mean internal rotation strength in the belly-press position for the operative shoulder was 8.12 ± 2.89 kg compared with 8.50 ± 3.03 kg (P = .13). Four of 20 shoulders showed mild tendinopathic changes of the subscapularis tendon but no partial or complete tear. One patient exhibited fatty degeneration Goutallier stage 1. Conjoint tendon was in continuity in all 20 shoulders on MRI scans.

CONCLUSION

Abduction, but not internal rotation strength, was slightly reduced after the Latarjet procedure at a mean of 8 years of follow-up. The subscapularis tendon was intact based on ultrasound examination, and the conjoint tendon was intact based on MRI scans. Subscapularis muscle girth relative to the supraspinatus muscle remained intact from preoperative measurements based on MRI scans.

Arthroscopic Anatomic Glenoid Reconstruction With Distal Tibial Allograft and Hybrid Fixation

Glenoid grafting is the standard surgical treatment for recurrent shoulder instability with significant glenoid bone loss. Arthroscopic anatomic glenoid reconstruction using a distal tibial allograft for anatomic glenoid reconstruction has recently been gaining attention. This article describes the use of a hybrid graft fixation technique with 1 suture-EndoButton device and 1 compression screw in arthroscopic anatomic glenoid reconstruction using distal tibial allograft.

Arthroscopic bone block stabilisation procedures for glenoid bone loss in anterior glenohumeral instability: A systematic review of clinical and radiological outcomes

INTRODUCTION

Recurrent shoulder instability is frequently associated with glenohumeral bone loss. Recently there has been a surge of interest in arthroscopically performed bone block procedures. The aim of this systematic review was to determine the clinical and radiological outcomes of arthroscopic glenoid bone block stabilisation for recurrent anterior dislocation.

METHODS

This systematic review was performed in accordance with PRISMA guidelines. The search strategy was applied to MEDLINE and Embase databases on 20^th July 2020. Studies reporting either clinical or radiological outcomes following arthroscopic bone block stabilisation for recurrent anterior dislocation were included. Primary outcomes were function and instability scores. Secondary outcomes included recurrent instability, graft union and resorption rates, return to activity/sports, and complications. Pooled analysis was performed when an outcome was uniformly reported by more than one study. Critical appraisal of studies was conducted using the Methodological Index for Non-Randomized Studies (MINORS) tool.

RESULTS

Application of the search strategy resulted in the inclusion of 15 eligible studies; 12 used iliac crest bone graft while 3 used distal tibial allograft. The overall population comprised 265 patients (mean age range, 25.5-37.5 years; 79% of participants were men). All post-operative outcome scores were significantly improved, and the overall rate of recurrent instability was low (weighted mean 6.6%, range 0-18.2%) at mean follow up of 30.4 months. The Rowe score was the most frequently reported outcome measure, improving on average by 53.9 points at final follow-up, exceeding the minimal clinically important difference (MCID) threshold. Graft union rates ranged between 92-100% in 8 out of 10 studies at mean follow up range 6-78.7 months but two reported lower rates ranging from 58.3-84% for autografts and 37.5% for allografts. Graft resorption rates averaged between 10-16% for autografts and 32% for allografts. Hardware-related complications occurred in 2% with the most frequent being screw breakage or symptomatic mechanical irritation.

CONCLUSION

Arthroscopic bone block stabilisation is associated with high rates of graft union, significant improvements in the WOSI, Rowe, Constant and SSV scores (exceeding MCID thresholds where known), and a low rate of complications, including re-dislocation in the short to mid-term. Graft union rates were high, but the long-term implications of graft resorption (which occurs more frequently with allograft) are unknown. Longer follow-up of these patients and future experimental studies are required to further examine the effects of graft type and fixation methods.

LEVEL OF EVIDENCE

IV; systematic review.

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.

[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.

Chapter 6: Attritional Glenoid Bone Loss in the Shoulder: Operative Considerations

Patients with recurrent anterior shoulder instability often have glenoid bone loss present in addition to soft tissue pathologies. It is known that patients with significant glenoid bone loss are best treated with a boney augmentation procedure as opposed to a soft tissue Bankart repair because of the high rate of recurrent instability that results from a Bankart repair. Although the Latarjet technique has been the gold-standard treatment for patients with glenoid bone loss because of the low incidence of recurrent instability, it has a high complication rate and a steep learning curve. Herein, the authors present the technique and outcomes for arthroscopic anatomic glenoid reconstruction that has a similar complication rate to the Bankart repair but with a low recurrence rate similar to the Latarjet. This procedure is safe, has a short learning curve, low recurrence rate, and positive patient-reported outcomes.

Editorial Commentary: Arthroscopic Glenoid Reconstruction With Subscapularis Tenodesis Results in Promising Clinical Outcomes, but Concerns Regarding Graft Resorption Rates Persist: A Long Way Toward a More Perfect Union

The pros and cons of open and arthroscopic shoulder stabilization procedures have been studied exhaustively. Yet, in many situations, the rates of recurrent instability and overall complications associated with these techniques remain unacceptably high. Perhaps paradoxically, the refinement of arthroscopic shoulder stabilization techniques has only intensified the debate between proponents of either open or arthroscopic approaches, and although significant (however "significant" is defined), anteroinferior glenoid bone loss has historically been thought to constitute a relatively strong indication for an open bone augmentation procedure, surgeons, to their great credit, continue to push the limits of what can be accomplished arthroscopically. Arthroscopic glenoid reconstruction has emerged as a viable option that may represent "the best of both worlds." Although modifications to the originally described arthroscopic glenoid reconstruction technique are promising, concerns persist regarding the fate of the graft and the durability of the procedure beyond short-term follow-up.

Arthroscopic Anatomic Glenoid Repair Using Distal Tibial Allograft and an Inferior-to-Superior Capsular Shift

Traumatic anterior dislocation of the shoulder accounts for the vast majority of shoulder dislocations. Recurrence following initial traumatic dislocation is common, and the risk is increased by the presence of both bony and soft-tissue damage. Arthroscopic procedures have been described to address each of these etiologies individually but have not provided a technique to address bony and soft tissue pathology concurrently. This paper describes an all-arthroscopic, anatomic glenoid repair using distal tibial allograft with an inferior-to-superior capsular shift, addressing significant glenoid bone loss and capsular laxity with a single operation.

Arthroscopic Anatomic Glenoid Reconstruction Using Distal Tibial Allograft for Recurrent Anterior Shoulder Instability: Clinical and Radiographic Outcomes

BACKGROUND

The all-arthroscopic anatomic glenoid reconstruction technique using a distal tibial allograft avoids damage to the subscapularis muscle and allows repair of the capsulolabral tissue.

PURPOSE

To analyze the clinicoradiologic outcomes of patients who underwent this procedure to treat anterior shoulder instability with glenoid bone loss with a minimum 2-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Over 6 years, 73 patients (52 male and 21 female; mean age, 28.8 years) under the care of the same surgeon underwent arthroscopic stabilization with capsulolabral Bankart repair and bony allograft augmentation of the glenoid for recurrent shoulder instability with significant bone loss. Pre- and postoperative patient-reported functional assessment was performed using 2 questionnaires, the Western Ontario Shoulder Instability Index (WOSI) and the Disabilities of the Arm, Shoulder and Hand, and radiological assessment was performed using radiographs and computed tomography scans obtained preoperatively and approximately 1 year later (mean ± SD, 0.9 ± 1.1 years).

RESULTS

The mean follow-up was 4.7 ± 1.1 years. The mean pre- and postoperative WOSI scores were 71.1 ± 17.5 and 25.6 ± 21.9, respectively (P < .001). There were no recurrences of dislocation, although 1 patient had symptoms of subluxation; however, 5 patients had hardware complications that required screw removal. There were no cases of nerve injury. Postoperative computed tomography scans were available for 66 patients. Seven patients were lost to follow-up. The graft union rate was 100%. Overall, graft resorption was <50% in 86% of patients (57/66). Eighteen patients (27%) had no resorption (grade 0), 39 (59%) had <50% (grades 1 and 2), and 9 (14%) had ≥50% (grade 3); however, none had symptoms of instability. The mean alpha angle of the screw between the screw shaft axis and the native glenoid axis was 18.3°± 5.7°. Graft positioning was flush with the glenoid in 61 of 66 patients (92.4%), and vertical positioning was excellent in 64 of 66 patients (97.0%) (3- to 5-o'clock position).

CONCLUSION

Arthroscopic stabilization using distal tibial allograft augmentation resulted in excellent clinicoradiologic outcomes at a 2-year follow-up. This procedure has the advantages of being an anatomic reconstruction that addresses bony and soft tissue instability. However, long-term follow-up studies are necessary for better assessment of outcomes.

Use of allograft to reconstruct anterior bony glenoid defect in chronic glenohumeral instability: a systematic review

INTRODUCTION

Bone-block procedures are well-established in anterior chronic shoulder instability treatment. Autograft with the coracoid process (Bristow-Latarjet procedures) and iliac crest (Eden-Hybbinette) are the most frequent source of bone but the use of allograft is also possible. The objective of this review is to assess clinical and radiographic outcomes after bony allograft reconstruction in anterior glenohumeral instability.

MATERIAL AND METHODS

Medline, Cochrane, Embase databases were searched for studies reporting on bone allograft reconstruction in anterior glenohumeral instability with glenoid defect. We conducted a systematic review of studies with all levels of evidence reporting on clinical or radiological outcomes or both.

LEVEL OF EVIDENCE

IV.

RESULTS

Ten studies met the inclusion criteria for the review; 283 shoulders were included with a mean age of 26 years (17-63) and mean follow-up of 34 months (4-168). Glenoid reconstruction was performed using bone from different source: femoral head (1 study), distal tibia allograft (5 studies), and iliac crest (4 studies). Allografts were fresh in 4 studies, demineralized in 2 studies, and freeze-dried after sterilization in 1 study. All scores performed in the different studies increased between pre-operative and post-operative evaluations (mean + 36.8 points for the ASES). Global rate of recurrence was 3.9% (11 patients) (0-11%), comprising 6 cases of dislocation (2.1%) and 5 subluxations (1.8%). Allograft healing occurred in 93.5% of cases.

CONCLUSIONS

This systematic review data suggest that allograft reconstructions in anterior glenohumeral instability could be a viable alternative to similar reconstructions with autografts and provide close clinical/radiological outcomes, at short and mid-term follow-up. Prospective randomized studies are needed to confirm these results.

Benefits of bone graft augmentation to arthroscopic Bankart repair for recurrent anterior shoulder instability with glenoid bone loss

PURPOSE

Glenoid bone loss contributes to recurrent instability after arthroscopic Bankart repair alone. With significant glenoid bone loss, better results have been reported after arthroscopic Bankart repair with glenoid arc reconstruction. However, no reports compare augmentation using bone graft with non-augmentation for glenoid bone loss. The purpose of this study was to assess clinical results of an arthroscopic Bankart repair with or without arthroscopic bone graft augmentation. It was hypothesized that such bone graft augmentation would restore shoulder stability, and lead to excellent outcomes.

METHODS

Of 552 patients treated for anterior glenohumeral instability with arthroscopic Bankart repair, 68 met this study's inclusion criteria of glenoid bone loss over 20% and follow-up of at least 2 years. Patients were divided into 2 groups based on whether with bone graft augmentation for glenoid bone loss [Group A: n = 35, median age; 21 years (range 13-72 years)], or not (Group B: n = 33, median age; 21 years (range 13-50 years)]. For grafting, either autologous iliac bone or artificial bone made of hydroxyapatite was used. Rowe score, recurrence rate, and return to sport were used to assess the results.

RESULTS

Mean Rowe score was 95.0 (SD 10.6) in Group A and 69.7 (SD 27.2) in Group B (p < 0.05). The recurrence rate was 2.9% (1/36) in Group A and 48.5% (16/33) in Group B (p < 0.05). Regarding contact/collision athletes, 24 were contained in Group A and 22 in Group B. Of the patients with recurrence in Group B, 13 (59.1%) were contact/collision athletes. Finally, 50% of the contact/collision sports athletes for both groups returned to their sports at the same as pre-injury level. Of the 11 patients who returned to the same level of contact/collision sports in Group B, seven returned with residual instability. Nine athletes in Group A and 3 in Group B quit their sports for personal or social reasons.

CONCLUSIONS

Bone graft augmentation was beneficial when used with Arthroscopic Bankart repair for recurrent anterior shoulder instability with glenoid bone loss. Especially, for recurrent anterior shoulder instability with glenoid bone loss in contact/collision sports athletes, bone graft augmentation should be strongly considered as beneficial.

LEVEL OF EVIDENCE

Level IV.

The Biomechanical Effect of Bone Grafting and Bone Graft Remodeling in Patients With Anterior Shoulder Instability

BACKGROUND

Individual constitutional differences in glenoid shape and bone remodeling require a patient-specific and longitudinal approach to evaluate the biomechanical effects of glenoid bone grafting in patients with anterior shoulder instability.

PURPOSE

To quantify the longitudinal, in vivo, biomechanical effects of bone grafting, bone graft remodeling, and glenoid shape in patients with anterior shoulder instability by means of patient-specific finite element models.

STUDY DESIGN

Descriptive laboratory study.

METHODS

In total, 25 shoulders of 24 patients with anterior shoulder instability and anterior glenoid bone loss underwent an arthroscopic iliac crest bone graft transfer (ICBGT) procedure with either autologous or allogenic bone. Patient-specific finite element simulations based on preoperative, postoperative, and follow-up computed tomography scans were used to quantify the bone-mediated stability ratio (SR) and the distance to dislocation. Additionally, the relationship between glenoid morphological parameters and the SR was assessed.

RESULTS

The ICBGT procedure significantly increased the SR and distance to dislocation in the 2-, 3-, and 4-o'clock directions immediately after the surgical intervention (P < .01) in both the autograft and the allograft groups. Although the SR and distance to dislocation decreased subsequently, autografts showed long-term effects on SR and dislocation distance in the 3-o'clock direction (P < .01) and on SR in the 4-o'clock direction (P < .01). Allografts showed no significant effect on SR and dislocation distance in long-term follow-up (P > .05). Overall, glenoid retroversion as well as cavity depth predicted stability in all 4 dislocation directions, with glenoid cavity depth showing the highest correlation coefficients (R = 0.71, 0.8, 0.73, and 0.7 for 2-, 3-, 4-, and 5-o'clock, respectively).

CONCLUSION

The autologous ICBGT procedure biomechanically improved anterior shoulder stability in long-term follow-up, whereas the use of allografts did not show any bone-mediated biomechanical effect at follow-up due to resorption. Furthermore, in addition to measurements of defect extent, the glenoid depth and version seem to be useful parameters to determine the biomechanical effect and need for glenoid bone grafting in patients with shoulder instability.

CLINICAL RELEVANCE

This study proposes the use of autologous bone grafts for a successful long-term stabilization effect. Additionally, this study proposes additional glenoid morphological measures to predict shoulder stability.

Massive graft resorption after iliac crest allograft reconstruction for glenoid bone loss in recurrent anterior shoulder instability

INTRODUCTION

Donor site morbidity constitutes the most prevalent source of complications during anatomic glenoid reconstruction. Therefore, the aim of this study was to evaluate the clinical and radiologic results of arthroscopic anatomic glenoid reconstruction using an allogenic, tricortical iliac crest bone graft for glenoid bone loss in recurrent anterior shoulder instability.

MATERIALS AND METHODS

Ten patients [one female/nine male, mean age 31.9 years (range, 26-40)] underwent allogenic iliac crest bone grafting and were evaluated clinically [range of motion, subscapularis tests, apprehension sign, Constant score (CS), Rowe score (RS), Walch-Duplay score (WD), Western Ontario Shoulder Instability Index (WOSI), Subjective Shoulder Value (SSV)] and radiographically [3-dimensional computed tomography (CT) scans].

RESULTS

After 23.2 months, the CS averaged 90 points (range, 84-98), RS 83 points (range, 50-100), WD 81 points (range, 50-100), WOSI 72% (range, 41-86) and the SSV 83% (range, 70-95). All patients showed a free range of motion and intact subscapularis muscle function. The apprehension sign was positive in three patients (30%) with a recurrent subluxation in one patient (10%). The glenoid surface area increased significantly from 84.4% (range, 73.5-92.1) preoperatively to 118.4% (range, 105.6-131.2) after surgery, while the glenoid defect was significantly reduced from 16.2% (range, 9.2-26.5) to 0.6% (range, 0-1.6). One year postoperative, total resorption of the allografts was observed with a glenoid surface area of 86.6% (range, 76.4-98.0) and corresponding increase of the glenoid defect to 14.0% (range, 2.9-23.6).

CONCLUSION

Arthroscopic glenoid reconstruction using an iliac crest bone allograft achieves satisfactory clinical results and glenohumeral stability during a short-term follow-up. However, this procedure was not observed to accomplish an anatomic reconstruction of the glenoid concavity due to excessive graft resorption.

LEVEL OF EVIDENCE

Level IV, case series, therapeutic study.

Innovative Approaches in the Management of Shoulder Instability: Current Concept Review

PURPOSE OF REVIEW

This article summarises the latest innovations and concepts in the management of shoulder instability associated with glenoid bone loss.

RECENT FINDINGS

The management of shoulder instability has undergone significant evolution in the last century with rapid strides being made in the last few decades due to the transition from open to arthroscopic techniques allowing management of pathological entities which were previously untreatable. However, there is no consensus on treatment methods, especially in the presence of glenoid bone loss. The complication profile associated with non-anatomic glenoid bony reconstruction procedures has triggered research for alternate techniques using free bone grafts. Open Latarjet procedure continues to be the gold standard in the face of glenoid bone loss; however, arthroscopic anatomic glenoid reconstruction with bone block grafts is gaining in popularity and is associated with excellent short-term clinico-radiologic outcomes. Arthroscopic anatomic glenoid reconstruction using bone grafts has been proposed as an alternative to the complex all-arthroscopic Latarjet procedure with excellent short-term results, minimal complications and a relatively easier learning curve. Capsular reconstruction has emerged as option for the management of instability with poor quality or absent capsular tissue. Future long-term outcome studies and randomised comparative trials will determine if these innovations stand the test of time.