Arthroscopic Autologous Scapular Spine Bone Graft Combined With Bankart Repair for Anterior Shoulder Instability With Subcritical (10%-15%) Glenoid Bone Loss

Arthroscopic Iliac Crest Autograft Glenoid Augmentation Using Tape Cerclage Fixation for Bony Deficiency and Recurrent Anterior Shoulder Instability Improves Functional Outcomes and Achieves High Union Rates With Graft Resorption in Nonloaded Areas

PURPOSE

To evaluate the clinical outcomes, return-to-sport rate, and graft remodeling after arthroscopic iliac crest bone autograft (ICBA) tape cerclage fixation for glenoid bone loss (GBL) in recurrent anterior shoulder instability.

METHODS

Case series of patients with recurrent anterior shoulder instability with GBL ≥15% who underwent arthroscopic ICBA metal-free tape cerclage fixation between February 2019 and March 2022 with a minimum follow-up of 2 years. Range of motion, patient-reported outcomes, return to sport, instability recurrence, and complications were collected preoperatively and at postoperative follow-ups. Graft resorption mapping was assessed by evaluating the distribution of articular surface remodeling on sagittal computed tomography scans. The graft surface was divided in 2 columns: the inner (loaded) column and the outer (nonloaded) column.

RESULTS

Twenty-eight patients with a mean age of 29.1 ± 7.9 years and a mean follow-up of 37.6 ± 5.8 months were included. The mean GBL was 18.4% ± 3.4% (range, 15%-25%). External rotation was 4° lower (P < .001) compared to the uninjured side. Patient-reported outcomes significantly improved from baseline to 2-year follow-up (P < .001): Western Ontario Shoulder Instability Index, 37.2 ± 18.7 to 94.9 ± 8.8; Rowe, 30.2 ± 16.4 to 96.1 ± 11.5; Constant-Murley, 83 ± 13.6 to 98.7 ± 3.2; and Subjective Shoulder Value, 43.5 ± 21.3 to 96.5 ± 8.3. Twenty-one patients (88%) returned to their previous sport level at a mean of 4.8 ± 1.7 months. No recurrent instability was reported. The glenoid surface area increased from 81.6% preoperatively to 120.1% immediately postsurgery (P < .001) and decreased to 101.2% at 1 year (P < .001) and to 98.2% at 2 years postoperative (P = .018). Graft resorption mapping showed higher osteolysis of the graft in the nonloaded area compared to the loaded area at 2 years postoperative (94.2% ± 12.9% vs 8.7% ± 15%, respectively, P < .001).

CONCLUSIONS

Arthroscopic glenoid reconstruction using ICBA fixed with tape cerclage is a safe and effective treatment for recurrent anterior shoulder instability with GBL greater than 15% at short-term follow-up. The procedure shows a high union rate, with articular graft surface resorption predominantly affecting nonloaded areas.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The scapula spine may not be a suitable source of bone graft for glenoid reconstruction in critical bone loss

BACKGROUND

The hypothesis is that the scapula spine can provide a graft of suitable dimensions for use in cases of shoulder instability with critical bone loss. We aimed to investigate its utility with grafts of differing sizes.

METHODS

The scapula spine was measured on computed tomography scans of 50 patients who had undergone anterior stabilization. The theoretical ability to harvest a graft of either 2 × 1 × 1 cm or 2 × 0.8 × 0.8 cm was analyzed.

RESULTS

Using the 2 × 1 × 1 cm threshold, 36% of the scapulae had at least 1 zone from which a suitable graft could be obtained. 61% had only 1 zone from which a suitable graft could be obtained. Using the 2 × 0.8 × 0.8 cm threshold, 72% had at least 1 zone from which a graft could be obtained. A total of 47% met the threshold in 1 zone only.

CONCLUSION

The scapula spine can be used as a source of autograft. Grafts up to 2 x 1 × 1 cm can be harvested in some individuals; however, the anatomy is very variable.

Remplissage May Decrease the Redislocation Rate After Arthroscopic Bankart Repair in Patients With an Engaging Hill-Sachs Defect: A Systematic Review and Meta-analysis of Studies With Minimal 2-Year Follow-up

BACKGROUND

The redislocation rate after arthroscopic Bankart repair (BR) among patients with a Hill-Sachs lesion (HSL) may be reduced with the use of remplissage.

PURPOSE

To investigate the outcomes of adding remplissage to an arthroscopic BR in patients with concomitant HSL.

STUDY DESIGN

Meta-analysis; Level of evidence, 3.

METHODS

PubMed and ScienceDirect databases were searched between February 2022 and April 2023 with the terms "remplissage" and "shoulder instability" according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The inclusion criteria were formed using the population, intervention, control, and outcome method; the investigation included studies that compared BR with and without remplissage and had ≥24 months of follow-up.

RESULTS

From 802 articles found during the initial search, 7 studies with a total of 837 patients-558 receiving isolated BR (BR group) and 279 receiving BR with remplissage (BR+REMP)-were included. The probability of recurrence of instability among patients with an engaging HSL was significantly diminished in the BR+REMP group compared with the BR group (odds ratio, 0.11; 95% CI, 0.05 to 0.24; P < .001). Regarding shoulder range of motion, the BR+REMP group achieved increased forward flexion (mean difference [MD], 1.97°; 95% CI, 1.49° to 2.46°; P < .001) and decreased external rotation in adduction (MD, -1.43°; 95% CI, -2.40° to -0.46°; P = .004) compared with the BR group. Regarding patient-reported outcome measures, the BR+REMP group had Rowe (MD, 2.53; 95% CI, -1.48 to 6.54; P = .21) and Western Ontario Shoulder Instability Index (WOSI) (MD, -61.60; 95% CI, -148.03 to 24.82; P = .162) scores that were comparable with those of the BR group.

CONCLUSION

Remplissage resulted in a 9-fold decrease in the recurrence of instability after arthroscopic BR in patients with HSL. Remplissage not only led to an increase in forward flexion but also only slightly limited patients' external rotation in adduction. WOSI and Rowe scores after remplissage at the final 24-month follow-up were comparable with those obtained after isolated Bankart repair.

Treatment of recurrent shoulder dislocation by arthroscopic subscapularis augmentation using the long head of the Biceps tendon

BACKGROUND

Recurrent anterior shoulder dislocation is a common shoulder problem, usually caused by a force from the front when the shoulder joint is abducted and externally rotated. In the present study, we investigated the effect of arthroscopic subscapularis augmentation using the long head of the biceps tendon on shoulder motion after restoring anterior stability of the joint in patients with 13.5-20% of scapular glenoid defects.

METHODS

Fifty patients admitted to our department with recurrent anterior shoulder dislocation between April 2017 and July 2021 were retrospectively analyzed. The patients were divided into two groups (groups A and B, n = 25 each) with comparable age, sex, hand dominance, and articular glenoid bone loss. Patients in group A were treated with arthroscopic Bankart repair and subscapularis augmentation, whereas those in group B underwent arthroscopic long head of the biceps transposition and subscapularis augmentation. All patients in both groups were followed up for more than 1 year, with a mean follow-up period of 20.1 ± 0.7 months (range, 13-28 months). The primary outcomes were changes in the visual analog scale score, Rowe classification, and Constant-Murley shoulder outcome score.

RESULTS

None of the patients in either group had experienced recurrent dislocation at 1-year follow-up. The visual analog scale scores decreased, and the Rowe and Constant-Murley scores improved significantly compared to the preoperative scores. Significant differences were observed in the forward flexion, abduction, and internal rotation angles of the shoulder joint in both groups at 1-year follow-up compared to baseline. The postoperative forward flexion (P = 0.143), abduction (P = 0.778), and internal rotation angles (P = 0.609) did not differ significantly between the two groups. At 1-year follow-up, the loss of angles of external rotation at the side and external rotation at 90° abduction in group B exhibited significantly less angular loss than group A.

CONCLUSION

Arthroscopic subscapularis augmentation using the long head of the biceps transposition technique was effective at restoring anterior stability in patients with 13.5-20% scapular glenoid defects. It was more effective at restoring the external rotational function of the shoulder joint than arthroscopic Bankart repair and subscapularis augmentation.

A Technique to Augment Arthroscopic Bankart Repair With or Without a Metal Block: A Comparison

Introduction: Arthroscopic Bankart repair (ABR) is associated with an increased failure rate over time. The Recenter implant, a metal block, is designed to reinforce capsulolabral repair. The aim of this study was to evaluate whether the addition of the Recenter implant to ABR reduces the rate of recurrence in patients with glenohumeral anterior instability. Materials and Methods: This was a retrospective, multicentric case-control study focusing on patients surgically treated for anterior shoulder instability from February 2012 to November 2019. This study compared patients undergoing ABR augmented with the "Recenter" implant (augmented ABR group) against those receiving traditional ABR. Primary outcomes measured included recurrence rates. Secondary outcome measures included functional scores (Walch-Duplay and the subjective shoulder test [SST], the auto Rowe score, satisfaction, pain, and the presence or absence of subjective subluxation and apprehension), return to sports, the range of motion, as well as other complications. Results: Thirty-two patients with augmented ABR were compared to forty-eight patients in the traditional ABR group, with mean follow-up periods of 5.2 ± 1.3 years and 6.1 ± 1.5 years, respectively. Three patients (9.4%) experienced recurrence in the "Recenter" group, versus eight (16.7%) in the other group (p > 0.05). The Walch-Duplay score was 70.2 ± 8.2 in the "Recenter" group and 64.2 ± 8 in the control group (p > 0.05). The SST score out of 100 was, respectively, 84.6 ± 6 and 81.5 ± 5.5 (p = 0.05). There were no early complications in the implant group. No statistically significant differences were observed between the two groups for the other outcomes. Conclusions: ABR safely restores shoulder stability in selected patients with subcritical glenoid bone deficiency. However, the addition of the Recenter metal implant did not improve outcomes compared to traditional Bankart repair and introduced presumed significant surgical time, technical challenges, and additional costs.

Approach to shoulder instability: a randomized, controlled trial

Background

The significant rate of recurrent instability following arthroscopic stabilization surgery points to a need for an evidence-based treatment approach. The instability severity index Score (ISI score) is a point-based algorithm that may be used to assist clinicians in selecting the optimal treatment approach, but its efficacy compared with a traditional treatment algorithm has not been previously validated. The aim was to compare two surgical treatment algorithms: the ISI score and a conventional treatment algorithm (CTA).

Methods

This was a prospective, randomized controlled trial involving participants who were randomized to either the ISI score or CTA and were followed for 24 months postrandomization. In the ISI score cohort, patients underwent a Latarjet procedure if they presented with a score >3 points. Those scoring ISI score ≦3 points underwent an arthroscopic Bankart repair. Patients randomized to the CTA group underwent a Latarjet procedure if the glenoid bone loss was > 25%. The primary outcome was the Western Ontario Shoulder Instability Index. Secondary outcomes included the American Shoulder and Elbow Surgeons score as well as recurrence rates between groups.

Results

Sixty-three patients were randomized to ISI score (n = 31) or CTA (n = 32). At two years, the Western Ontario Shoulder Instability Index score was similar between groups (ISI score: 84.1 ± 16.9, CTA: 85.7 ± 12.5, P = .70). Similarly, no differences were detected in American Shoulder and Elbow Surgeons scores (ISI score: 93.2 ± 16.2, CTA: 92.6 ± 9.9, P = .89). Apprehension was reported in 18.5% for the ISI score group and 20% in the CTA group (P = 1.00). At a 24-month follow-up, there was no difference in redislocations: one in ISI score group and none in the CTA group (P = .48). There were two revision surgeries in the ISI score group and two in the CTA group.

Conclusion

This study did not demonstrate any differences in functional outcomes, the incidence of apprehension, or failure rates between the two treatment algorithms at 24-month follow-up.

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.

Management of bone loss in anterior shoulder instability

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

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).

Arthroscopic Posterior Bone Block Stabilization Using a Tricortical Autograft of the Ipsilateral Scapular Spine

Posterior bone grafting represents an emerging therapeutic approach for addressing recurrent instability in the posterior shoulder, particularly when coupled with substantial glenoid bone loss. Although not as prevalent as anterior instability, recent years have witnessed the development of numerous open and arthroscopic bony reconstruction methods. A technical gold standard for posterior bone grafting remains undefined, leading to ongoing advancements in bone grafting techniques. In response to past challenges associated with screw fixation, metal-free arthroscopic fixation procedures have been introduced to the realm of bone grafting. These metal-free methods often entail intricate transglenoid drilling, which poses potential surgical complexities and risks to both posterior and anterior soft tissues, as well as neurovascular structures. Therefore, we introduce an arthroscopic approach to posterior bone grafting using PEEK (polyether ether ketone) anchors with interconnected sutures and a scapular spine autograft. This method overcomes previous hurdles by facilitating the restoration of the posterior glenoid bone stock with precise positioning and secure fixation of the tricortical scapular spine bone autograft.

Reconsidering "Critical" Bone Loss in Shoulder Instability: 17-Year Follow-Up Study following Arthroscopic Bankart Repair

Background

Glenoid bone loss is a risk factor leading to the failure of arthroscopic Bankart repair. While 20-25% glenoid bone loss has long been considered the level to necessitate bony augmentation, recent studies indicate that 13.5% has a "subcritical" glenoid bone loss level, which is associated with decreased short- and medium-term functional scores. Few researchers worked on the long-term effect of "subcritical" or even less severe degrees of glenoid bone loss on redislocation rates and functional outcomes after arthroscopic Bankart repair. This study aimed to evaluate the effect of subcritical or less severe glenoid bone loss on redislocation rates and function after arthroscopic Bankart repair.

Methods

A patient cohort who had undergone computed tomography (CT) of glenoid bone loss and arthroscopic Bankart repair over 15 years ago was reviewed. Western Ontario Shoulder Instability (WOSI) score, Single Assessment Numeric Evaluation (SANE) score, redislocation after operation, mechanism of recurrence, and revision details were reviewed.

Results

Seventy-five patients were reassessed 17.6 ± 1.9 years following initial surgery. The age at enrolment was 26.8 ± 8.3 years. Twenty-two (29%) patients of the 75 patients had a redislocation on long-term follow-up, though this was not related to glenoid bone loss severity. The impaired functional score was found in patients with initial glenoid bone loss of 7% or more on long-term follow-up: WOSI (physical symptoms): 0.98 ± 2.00 vs 2.25 ± 4.01, p=0.04 and WOSI (total): 0.79 ± 1.43 vs 1.88 ± 3.56, p=0.04.

Conclusions

At a mean of 17.5 years following arthroscopic Bankart repair, redislocation occurs in over a quarter of 75 patients, and they are not related to initial glenoid bone loss severity. Impaired functional outcome is apparent in patients with initial glenoid bone loss of >7%, though this impairment does not seem sufficiently severe to warrant an alternative treatment approach.

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.

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.

Assessment of micromotion at the bone-bone interface after coracoid and scapular-spine bone-block augmentation for the reconstruction of critical anterior glenoid bone loss-a biomechanical cadaver study

BACKGROUND

Glenoid bone loss is among the most important risk factors for recurrent anterior shoulder instability, and a bony reconstruction is recommended in cases of critical bone loss (> 15%). The commonly used surgical techniques, including coracoid transfer, are associated with considerable complications. The aim of this study was to assess the motion at the glenoid-bone-block interface after coracoid and spina-scapula bone-block reconstruction of the anterior glenoid.

METHODS

Twelve cadaveric shoulders were tested. A 20% bone defect of the anterior glenoid was created, and the specimens were randomly assigned for glenoid augmentation using a coracoid bone block (n = 6) or a scapular spine bone block (n = 6). The glenoid-bone interface was cyclically loaded for 5000 cycles with a force of 170 N. The micromotion was tracked using an optical measurement system (GOM ARMIS) and was evaluated with the GOM Correlate Pro software.

RESULTS

The most dominant motion component was medial irreversible displacement for the spina-scapula (1.87 mm; SD: 1.11 mm) and coracoid bone blocks (0.91 mm; SD: 0.29 mm) (n.s.). The most medial irreversible displacement took place during the first nine cycles. The inferior reversible displacement was significantly greater for spina-scapula bone blocks (0.28 mm, SD: 0.16 mm) compared to coracoid bone blocks (0.06 mm, SD: 0.10 mm) (p = 0.02).

CONCLUSIONS

The medial irreversible displacement is the dominant motion component in a bone-block reconstruction after a critical bone loss of the anterior glenoid. The spina-scapula and coracoid bone blocks are comparable in terms of primary stability and extent of motion. Thus, spina-scapula bone blocks may serve as alternatives in bony glenoid reconstruction from a biomechanical point of view.

Arthroscopic Xenograft With Cerclage Fixation: A Method for Glenoid Bone Loss Reconstruction With Cerclage Fixation Using a Specific Posterior Guide

Large glenoid bone defects are closely associated with high failure rates after arthroscopic Bankart repair in chronic anterior shoulder instability; therefore nowadays the glenoid bone grafting reconstruction procedure is strictly recommended. On the contrary, the optimal grafting procedure is still controversial because there is considerable concern about the resorption rate of allografts, donor site morbidity of the autografts, and sequelae caused by the use of metal fixation devices in proximity of the shoulder joint. We describe an all-arthroscopic technique for anatomic reconstruction of the glenoid that uses a previously shaped xenograft assembled with a metal-free fixation device using 2 ultra-high-strength sutures (FiberTape Cerclage System; Arthrex, Naples, FL), using a specific posterior guide (Arthrex, Naples, FL) in combination with upper third subscapularis augmentation.

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.

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.

Arthroscopic Dynamic Anterior Stabilization Using Either Long Head of the Biceps or Conjoined Tendon Transfer for Anterior Shoulder Instability Results in a Similarly Low Recurrence Rate

PURPOSE

To compare the clinical outcomes of arthroscopic dynamic anterior stabilization (DAS) between transferring the long head of the biceps (DAS-LHB) and the conjoined tendon (DAS-CT) for anterior shoulder instability with <15% glenoid bone loss.

METHODS

From January 2016 to May 2019, a total of 63 patients who underwent DAS for recurrent anterior shoulder dislocation with <15% glenoid bone loss were included, comprising 33 patients in DAS-LHB group and 30 patients in DAS-CT group. Clinical outcomes were assessed preoperatively and at a minimum 3-year follow-up, including patient-reported outcomes, range of motion, and return to sports (RTS). Postoperative recurrent instability (including dislocation, subluxation, and subjective instability with a positive apprehension test), revisions and complications also were recorded.

RESULTS

No significant demographic characteristics difference was detected between the DAS-LHB (26.3 ± 7.9 years) and DAS-CT groups (26.0 ± 6.7 years). At the latest follow-up, there were no significant differences between the 2 groups in functional scores: Oxford Shoulder Instability Score (14.8 ± 2.8 vs 15.2 ± 3.6), Rowe score (95.9 ± 6.5 vs 93.2 ± 10.2), visual analog scale for pain (0.8 ± 1.2 vs 0.7 ± 1.7), and American Shoulder and Elbow Surgeons (95 ± 8.8 vs 95.2 ± 9.1) (all P > .218). No significant difference was detected between groups in the rates of RTS (90.1% vs 86.7%, P = .700) and RTS at previous level (78.7% vs 73.3%, P = .258), respectively. No recurrent dislocation occurred in either group. One patient felt occasional subluxation in the DAS-LHB group, and one was positive for the apprehension test in each group. One patient presented with postoperative shoulder stiffness and underwent a secondary arthroscopic debridement in the DAS-CT group.

CONCLUSIONS

Comparable rates of recurrence, complication, return to sports, and subjective shoulder function were observed between DAS-LHB and DAS-CT groups.

LEVEL OF EVIDENCE

Ⅲ; retrospective comparative therapeutic trial.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

Early Treatment of Shoulder Pathology Is Necessary but Not Enough Is Being Performed

Delayed treatment of shoulder instability results in bone loss requiring more-complicated surgery, in turn resulting in less-optimal outcomes. Similarly, delayed treatment of repairable rotator cuff tears results in irreparable tears requiring more-complicated surgery and resulting in less-optimal outcomes. Delayed treatment of shoulder pathology is a problem. Solutions include education and research investigation.

Arthroscopic Autologous Scapular Spine Bone Graft for Recurrent Anterior Shoulder Dislocation With Subcritical (10%-15%) Glenoid Bone Loss

For anterior shoulder instability with subcritical glenoid bone loss (10%-15%), there is no consensus on the optimal treatment. Now, we describe the technique of using autogenous scapular spine bone graft for recurrent anterior shoulder dislocation. This procedure can effectively increase the anterior bone barrier and strengthen the effect of Bankart repair. In addition, this procedure not only avoids coracoid or iliac crest transfer, but also adopts nonrigid fixation, which makes it safer and more convenient. We believe that this technique will provide a promising alternative to the surgical treatment of recurrent anterior shoulder dislocation in subcritical glenoid bone loss (10%-15%).

Navigation-Guided Trans-glenoid Flexible Fixation Technique for Arthroscopic Autologous Iliac Crest Grafting Treatment of Recurrent Shoulder Dislocation

Recurrent anterior shoulder dislocations accompanied by severe glenoid bone defects are typically treated with arthroscopy. Until now, autologous iliac grafting has been reported with excellent results, and different techniques of bone fixation have been introduced by numerous scholars. In this article, we introduce a specially designed guide that can achieve accurate positioning of the bone graft and a nonrigid graft fixation technique with a single EndoButton (Smith & Nephew). Using this technique, we greatly simplify the arthroscopic procedure and avoid the use of screws.

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.

Editorial Commentary: Surgical Treatment of Shoulder Instability With Subcritical Glenoid Bone Loss Requires Innovation: Bankart May Risk Significant Recurrence and Latarjet May Risk Significant Complications

The patient with a history of shoulder dislocation and subcritical (10%-15%) glenoid bone loss presents a complicated scenario. The "safest" procedure (arthroscopic Bankart repair) may result in a high rate of failure and risk of further surgery. The most successful procedure for avoiding recurrence (Latarjet) comes with potentially high complication rates (of up to 20%), a steep learning curve, risk of permanent nerve injury (up to 15%), and substantial risk of subscapularis deficit. Innovation is most needed in surgery when current treatments lack success or risk significant complications. As surgeons, we are constantly striving to walk the line between using innovative techniques for our patients to better their lives and following the principle "first do no harm." This recent article describes the outcomes of a 2-cm segment of scapular spine harvested through a small incision and stabilized with suture anchors along the anterior glenoid, combined with an arthroscopic labral repair. The technique appears to be safe, and practical, bearing in mind that excellent reported outcomes must be shown to be reproducible. Ideally, we should not have to choose between relatively high failure rates with arthroscopic Bankart repair or the greater reported complication rates with Latarjet. Innovation will pave the way to our greater success.