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

Editorial Commentary: Open Distal Tibial Allograft with Screw Fixation for Distal Tibial Allograft Glenoid Reconstruction in Patients with Shoulder Instability May Result in Lower Recurrence Rates than Button Fixation

The glenoid rim is altered in up to 90% of shoulders with recurrent instability. Distal tibial allograft (DTA), an option for anatomic glenoid reconstruction (AGR), has excellent mid-term outcomes and low recurrence and resorption rates using open or arthroscopic technique. Optimal graft position in both the medial-lateral and vertical axes, adequate fixation, and restoration of soft-tissue balance is the key to successful outcomes. Regarding fixation methods, metal screw fixation is a standard for AGR with free bone block or Latarjet procedure. The main disadvantage of screw fixation is hardware prominence and irritation to surrounding bone and soft tissue (6.5%), the leading cause of revision surgery. Button fixation may mitigate hardware complications, but lead to greater graft malposition, resorption, and recurrence rates. The authors used an open approach with screw fixation for AGR with DTA, and restoration of the capsulolabral complex to reduce recurrent instability after surgery.

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 Evolution of Arthroscopic Shoulder Surgery: Current Trends and Future Perspectives

Arthroscopic shoulder surgery has undergone significant advancements over the past decades, transitioning from a primarily diagnostic tool to a comprehensive therapeutic approach. Technological innovations and refined surgical techniques have expanded the indications for arthroscopy, allowing minimally invasive management of shoulder instability and rotator cuff pathology. Methods: This narrative review explores the historical evolution, current trends, and future perspectives in arthroscopic shoulder surgery. Results: Key advancements in shoulder instability management include the evolution of the arthroscopic Bankart repair, the introduction of the remplissage technique for Hill-Sachs lesions, and the development of arthroscopic Latarjet procedures. Additionally, novel techniques such as Dynamic Anterior Stabilization (DAS) and bone block procedures have emerged as promising solutions for complex instability cases. In rotator cuff repair, innovations such as the suture-bridge double-row technique, superior capsular reconstruction (SCR), and biological augmentation strategies, including dermal allografts and bioinductive patches, have contributed to improving tendon healing and functional outcomes. The role of biologic augmentation, including biceps tendon autografts and subacromial bursa augmentation, is also gaining traction in enhancing repair durability. Conclusions: As arthroscopic techniques continue to evolve, the integration of biologic solutions and patient-specific surgical planning will likely define the future of shoulder surgery. This review provides a comprehensive assessment of current state-of-the-art techniques and discusses their clinical implications, with a focus on optimizing patient outcomes and minimizing surgical failure rates.

Latarjet Coracoid Transfer Versus Distal Clavicular Autograft for Anterior Shoulder Instability With Glenoid Bone Loss: A Biomechanical Comparison of 2 Graft Reconstructions in Various Medial Positions

Background

No biomechanical study has established the effect of different graft positions or bone block options on anterior glenohumeral joint stability.

Purpose/Hypothesis

The purpose of this study was to compare graft choice (distal clavicular vs coracoid autograft for Latarjet) and position on stability of the bone block for anterior glenohumeral instability. It was hypothesized that both grafts would be comparable if flush with the glenoid but that the sling effect of the Latarjet procedure would lead to greater stability in case of graft medialization.

Study Design

Controlled laboratory study.

Methods

Eight cadaveric shoulders were included. Defects stabilized using a distal clavicular graft and a coracoid graft were consecutively positioned at 0, 4, and 8 mm medially. The starting position was determined by the humeral head's being seated at its most medial position on the glenoid surface. Each experiment comprised maximal external rotation and glenohumeral abduction at 60° while applying a constant 50-N medial compressive force to the humerus under all conditions. The conjoint tendon was routed through a split in the subscapularis and loaded with a 5-N weight using a pulley system for all Latarjet trials to simulate the sling effect.

Results

Regarding the clavicular graft, the stability ratio significantly decreased versus the intact condition at all medial offsets (P = .007 for 0 mm, P < .001 for 4 mm, and P < .001 for 8 mm), and it was significantly lower in the 4-mm versus 0-mm position (P = .008), significantly higher in the 4-mm versus 8-mm position (P < .001), and significantly lower in the 8-mm versus 0-mm position (P < .001). Regarding the coracoid graft, the stability ratio was comparable with intact for the 0-mm position (P = .12), while it was significantly lower in the 4-mm and 8-mm positions (P < .001 for both). The distal clavicular graft at 0-mm offset was comparable with the coracoid graft at 0-mm offset.

Conclusion

In shoulders with anterior glenoid bone loss, the coracoid and distal clavicular autografts were biomechanically comparable when placed flush with the glenoid. The distal clavicle at 0-mm offset did not restore stability compared with the intact specimen, but the Latarjet at 0-mm offset was not significantly different from the intact condition.

Clinical Relevance

The Latarjet procedure provides higher stability compared with distal clavicular autograft when medialized.

Reverse Hill-Sachs and Hill-Sachs Lesion Repair with Fresh Talus Osteochondral Allograft: A Series of 3 Patients

CASE

Hill-Sachs lesions and reverse Hill-Sachs lesions (HSLs) are common in patients with shoulder instability, and addressing these lesions effectively is crucial for patient outcomes. Our study investigates a novel technique using talus osteochondral allografts (TOA) for the treatment of these lesions. The TOA offers several advantages, including congruency to the humeral head, dense bone structure, and a reduced risk of contamination compared with other allografts.

CONCLUSION

We present 3 patients with large engaging Hill-Sachs lesions or reverse HSLs, who were treated using a TOA, highlighting its feasibility and positive clinical outcomes.

Allograft Resorption Following Arthroscopic Anatomic Glenoid Reconstruction Is Part of Remodeling to Restore the Native Glenoid Size and Shape 6.9 Months Postoperatively

PURPOSE

To determine if the distal tibia allograft (DTA) remodels after arthroscopic anatomic glenoid reconstruction (AAGR) to restore the native glenoid size and shape postoperatively.

METHODS

This is a retrospective study on patients who underwent AAGR with DTA between 2013 and 2022 using screw fixation who have completed postoperative clinical follow-up for a minimum of 2 years and have an available postoperative computed tomography (CT) scan. Glenoid width (anterior-posterior) and height (superior-inferior) were measured using Horos and Meshmixer on an en face view. The measured glenoid width was compared to the predicted glenoid width based on height using the following equation: Width(mm) = 2.53mm + 0.71 ∗ Height(mm), and the difference between the 2 variables was calculated. Data analysis used a paired t test, Pearson correlation, and receiver operating characteristic curve at a .05 significance level.

RESULTS

In 109 patients included in this study, the mean ± SD age at surgery was 28.2 ± 9.6 years, mean ± SD body mass index was 26.1 ± 5.0, and mean ± SD CT follow-up was 1.0 ± 1.1 years, including 73 primary surgeries (67%), 81 men (74%), and 52 right-sided operative shoulders (48%). In all 109 patients, the predicted glenoid width (28.5 ± 2.5 mm) was significantly smaller than the measured glenoid width (30.7 ± 4.2 mm) (P < .001). A significant negative correlation was found between CT follow-up time and the difference between measured and predicted glenoid width (i.e., measured and predicted glenoid width became more similar as time passed postoperatively). A cutoff time of 6.9 months was identified for graft remodeling (area under the curve, 0.759; P < .001). In patients with ≥6.9 months between surgery and postoperative CT (n = 65), there was no difference between predicted and measured postoperative glenoid width (28.6 ± 2.6 mm, 29.4 ± 3.7 mm, respectively; P = .099). In patients with <6.9 months between surgery and postoperative CT (n = 44), the predicted glenoid width was significantly smaller than the measured glenoid width (28.4 ± 2.3 mm, 32.7 ± 3.9 mm, respectively; P < .001).

CONCLUSIONS

Predicted and measured postoperative glenoid width did not differ significantly in patients who had undergone AAGR with at least 6.9 months between surgery and postoperative CT. These findings support the hypothesis that the allograft remodels following AAGR with DTA to restore the native glenoid size and architecture.

CLINICAL RELEVANCE

These findings will help direct the size of bone blocks used in AAGR with DTA in the future to optimize surgical outcomes.

Screw Fixation Has Better Outcomes, Lower Incidence of Redislocation, and Lower Bone Resorption Than Button Fixation for Arthroscopic Anatomic Glenoid Reconstruction With Distal Tibia Allograft: A Matched Cohort Analysis

PURPOSE

To compare the clinical outcomes between patients who received arthroscopic anatomic glenoid reconstruction (AAGR) using distal tibia allograft with button fixation versus screw fixation.

METHODS

A retrospective chart review was conducted for all patients who underwent AAGR with button or screw fixation between 2012 and 2021. Patients were matched at a 1:1 ratio on the basis of sex, type of surgery, and time since surgery. All patients who were included had a minimum clinical follow-up of 2 years. Study outcomes compared Western Ontario Shoulder Instability (WOSI) Index scores, recurrence of instability, incidence of revision surgeries, and computed tomography readings.

RESULTS

In total, 44 patients were included with 22 patients in each group. The preoperative glenoid bone loss was 22.57 ± 8.06% in the screw group and 22.92 ± 8.84% in the button group (P = .898). Both groups demonstrated a significant improvement in WOSI from preoperative to latest follow-up; however, patients in the screw group demonstrated significantly better WOSI scores at both 2-year (P = .003) and latest follow-up (P = .019) compared with the button group. Recurrent dislocation was observed in 9 patients (40.9%), all of whom underwent button fixation (P < .001). Two patients in the screw group experienced hardware complications (P = .488). Individuals who underwent button fixation were significantly more likely to undergo a revision surgery for recurrent instability (P = .011). Individuals in the button group demonstrated a significantly smaller mean graft anteroposterior diameter postoperatively (P < .001).

CONCLUSIONS

AAGR with both screw fixation results in significantly improved WOSI scores at minimum 2-year follow-up. Button fixation has a significantly greater incidence of redislocation. Radiographic findings suggest that on average, button fixation results in greater-grade bone resorption and subsequently smaller postoperative glenoid anteroposterior width than screw fixation.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.

Biomechanical Evaluation and Surface Analysis of Glenoid Reconstruction Using a Subtalar Joint Allograft for Significant Glenoid Bone Loss in Recurrent Shoulder Instability: A Novel Alternative Graft Option

BACKGROUND

Glenoid and humeral head bone defects are common in chronic shoulder instability. The talus, and more specifically, the subtalar joint, has been proposed as a unique allograft from which bipolar bone loss can be addressed. However, there are few biomechanical data or joint reconstruction analyses of the glenoid using the posterior facet of a subtalar joint allograft (STA).

PURPOSE

To compare the contact mechanics of an STA versus a coracoid graft (Latarjet procedure) versus a distal tibial allograft (DTA) for anatomic glenoid reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 8 fresh-frozen, unpaired cadaveric specimens underwent repeated-measures biomechanical testing in 5 stages: native (intact) state, bone loss (30% glenoid bone defect), Latarjet procedure, glenoid reconstruction using a DTA, and glenoid reconstruction using an STA. A compressive load of 440 N was applied to the glenohumeral joint when the humerus was mounted to a dynamic tensile testing machine in 3 shoulder positions: 30° of abduction, 60° of abduction, and 60° of abduction with 90° of external rotation (ER). Average contact pressure, contact area, and peak contact pressure were determined from the sensors. Surface area and surface congruency were calculated using a custom script. Data were analyzed using analysis of variance.

RESULTS

There was a significantly higher surface area with glenoid reconstruction using the DTA (859 ± 78 mm2; P = .005) than with glenoid reconstruction using the STA (806 ± 88 mm2; P < .001) and the Latarjet procedure (692 ± 91 mm2). Surface congruency was significantly better with reconstruction using the DTA (2.0 ± 0.3 mm; P = .003) or the STA (1.9 ± 0.3 mm; P = .004) than with the Latarjet procedure (2.6 ± 0.4 mm). In all shoulder positions, the average contact pressure in the bone loss state was significantly higher than that in the native state (P < .05). All repair states restored average contact pressure to the native state at 60° of abduction and 60° of abduction with 90° of ER. There was less contact area after the Latarjet procedure than in the native state at 30° and 60° of abduction (P = .009 and P = .040, respectively). There was no significant difference in contact area and peak contact pressure after reconstruction with the DTA or STA compared with the native state.

CONCLUSION

Anatomic glenoid reconstruction using a DTA or STA restored average contact pressure, peak contact pressure, and contact area at 60° of abduction and 60° of abduction with 90° of ER in a cadaveric model. In addition, surface congruency and surface area improved over the traditional Latarjet procedure.

CLINICAL RELEVANCE

The STA showed comparable contact mechanics and surface geometry to the DTA. Further research is needed to determine the in vivo clinical outcomes of this new alternative graft.

The Effect of Concavity Restoration on Glenohumeral Stability in a Glenoid Bone Loss Model: Comparing Distal Tibial Allograft Reconstruction to Classic Latarjet

BACKGROUND

Distal tibial allograft (DTA) reconstruction for glenoid bone loss (GBL) has gained popularity. While recent studies have demonstrated that glenoid concavity is an important factor in native glenohumeral stability, there remains a paucity of data regarding concavity restoration during reconstructive procedures for GBL and its biomechanical effect.

PURPOSE

To compare the restoration of anterior glenohumeral stability and glenoid concavity after DTA and classic Latarjet procedures.

STUDY DESIGN

Controlled laboratory study.

METHODS

Nine human cadaveric specimens (mean age, 62.2 years; range, 52-69 years) underwent pretesting computed tomography (CT) to assess native glenoid concavity as determined by the glenoid depth and bony shoulder stability ratio (BSSR). GBL was created so the DTA and Latarjet graft could restore 100% of the native glenoid width. The rotator cuff tendons were loaded, and anterior stability testing was performed using a KUKA robot to apply a controlled anterior force with the shoulder in 90° of abduction and neutral external rotation. A motion capture system recorded humeral head translation. The following conditions were tested: intact, soft tissue Bankart lesion; bone loss model with DTA reconstruction; classic Latarjet procedure without conjoint tendon loaded; and classic Latarjet procedure with conjoint tendon loaded (sling effect). All specimens underwent posttesting CT to measure the BSSR of the DTA and Latarjet reconstructions. A repeated-measures analysis of variance was performed to compare the BSSR and anterior translations between the DTA and Latarjet reconstructions.

RESULTS

DTA produced greater concavity than the Latarjet procedure (BSSR: 0.45 vs 0.35; P < .001). There was no difference in anterior translation between the DTA and Latarjet procedures with the sling effect (5.1 mm vs 4.7 mm; P > .999). However, maximum anterior translation was decreased after the DTA procedure when compared with the Latarjet technique without the sling effect (5.1 mm vs 10.3 mm; P = .045).

CONCLUSION

DTA produces a more concave reconstruction and decreased anterior translation compared with the flatter reconstruction produced by the classic Latarjet procedure without the sling effect. DTA and the classic Latarjet procedure with conjoint tendon loading, however, yielded equivalent reductions in anterior translation.

CLINICAL RELEVANCE

Distal tibial allograft reconstruction is a biomechanically equivalent alternative to the classic Latarjet due to the restoration of glenoid concavity in addition to glenoid width. Surgeons should consider the role of concavity when addressing glenohumeral instability with bone loss.

Coracoid osteotomy approach for open free bone grafting of anterior glenoid defects

The utilization of free bone grafts to reconstruct large anterior glenoid defects has increased. Distal tibia allograft is commonly used due to its lack of donor site morbidity, ability to restore large bony defects, and near anatomic osteoarticular restoration. However, the intact coracoid and conjoint tendon often impair adequate visualization and access to perform an anatomic reconstruction during open free bone graft reconstruction and often requires violation of the subscapularis tendon to gain exposure. We present a surgical technique wherein we perform a coracoid osteotomy and subsequent repair to improve visualization when performing an open free glenoid bone graft in the setting when a patient has not undergone a prior coracoid transfer that does not require violation of the subscapularis tendon. This technique demonstrates excellent functional outcomes as well as radiographic healing of the coracoid osteotomy without pain or prominent hardware at the coracoid.

Biomechanical Outcomes of Glenoid Bone Graft Fixation Techniques: A Systematic Review

BACKGROUND

The Latarjet and other bony augmentation procedures are commonly used to treat anterior shoulder instability in the setting of significant glenoid bone loss. Although several fixation strategies have been reported, the biomechanical strength of these techniques remains poorly understood.

PURPOSE

To perform a systematic review of the biomechanical strength of glenoid bony augmentation procedures for anterior shoulder instability.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic search of the Medline, Embase, Web of Science, and Cochrane Library databases was performed to identify biomechanical studies evaluating various fixation strategies for coracoid and other bone transfer procedures for anterior shoulder instability. Biomechanical results included load to failure with both compression and traction forces, stiffness, and cyclic displacement. The quality of included articles was assessed based on the Quality Appraisal for Cadaveric Studies (QUACS) scale.

RESULTS

A total of 21 biomechanical studies comprising 486 specimens were included. The number of screws used and the addition of washers were found to significantly increase rigidity and load to failure. The comparison of fixation techniques demonstrated mixed results in load to failure between screw and alternative constructs including suture buttons and suture anchors. However, studies that tested graft displacement consistently found more graft displacement in buttons compared with screws. The median and mean of the QUACS scale were both 12, with a range of 10-13.

CONCLUSION

Biomechanical studies consistently demonstrated that when glenoid bone grafts were fixed with screws, the number of screws and use of washers significantly increased construct rigidity and load to failure. Different metal screw materials and sizes did not consistently demonstrate a significant difference in biomechanical strength. There are mixed results when comparing suture buttons to screw fixation. The evaluated studies revealed that all double metal screw constructs and the majority of suture button and anchor constructs were able to withstand the glenohumeral load reflective of activities of daily living using a 150-N threshold.

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.

Subscapularis Muscle Radiographic Integrity and Patient-Reported Outcomes Following Arthroscopic Anatomic Glenoid Reconstruction With Distal Tibial Allograft

BACKGROUND

Shoulder stabilization surgery has evolved over time, and bony augmentation procedures on the glenoid side are being performed more often. The Latarjet procedure modifies subscapularis anatomy because the conjoined tendon divides the subscapularis muscle fibers through a split/takedown, which has structural and functional implications. Arthroscopic anatomic glenoid reconstruction (AAGR) re-creates anatomy. This technique uses the Halifax portal to deploy and fix a distal tibial allograft (DTA) through the rotator interval, thus preserving the subscapularis anatomy.

PURPOSE/HYPOTHESIS

The purpose was to analyze the radiographic properties of the subscapularis muscle after AAGR. It was hypothesized that the subscapularis muscle structure remains preserved postoperatively.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review was performed comprising a consecutive series of patients treated with AAGR with DTA between November 2012 and April 2021 for traumatic anterior shoulder instability with glenoid bone loss. Patients were excluded if they had posterior instability, glenoid fracture, missing pre- or postoperative computed tomography (CT) scans, or only CT arthrogram available. Radiographic variables measured on CT scans included estimates of subscapularis muscle volume, subscapularis/infraspinatus muscle ratio, and fatty infiltration according to the Goutallier classification. Pre- and postoperative Western Ontario Shoulder Instability index scores were collected as a secondary outcome of this study.

RESULTS

Ninety-three patients were included in the study with a clinical follow-up of 2.3 ± 1.5 years (mean ± SD). The subscapularis volume increased from 185.91 ± 45.85 mL preoperatively to 194.1 ± 49.0 mL postoperatively (P = .006). The subscapularis to infraspinatus muscle ratio showed a significant increase from 0.96 ± 0.27 to 1.05 ± 0.30 after surgery (P = .002). All patients had a Goutallier stage of 0 before and after surgery. The Western Ontario Shoulder Instability scores showed a significant improvement from 64.8 ± 15.5 preoperatively to 28.2 ± 24.0 postoperatively (P < .001).

CONCLUSION

Patients who undergo AAGR with DTA for traumatic shoulder instability with glenoid bone loss have a preserved subscapularis muscle volume with no fatty infiltration, while showing a significant improvement in clinical outcomes.

Bone block options for treating glenoid bone loss and glenohumeral instability: A systematic review

Background

To systematically review the literature assessing glenoid bone loss restoration by different bone block options and compare their dimensions.

Methods

Systematic examination of articles in PubMed and EMBASE databases was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to find studies of bone grafts for treating anterior glenohumeral instability. Statistical analyses were conducted via Review Manager, and a p-value of <0.05 was statistically significant.

Results

Our review included 25 studies evaluating 870 shoulders. Traditional arc Latarjet (TL) had more depth than congruent arc Latarjet (CAL; p = 0.003). The coronal radii of curvature of TL, CAL, distal tibia, and iliac crest bone blocks were similar to native glenoid (p = 0.400, 0.817, 0.467, 0.216, respectively). CAL coracoid bone blocks restored significantly more glenoid surface area (30.3%) than TL bone blocks (p = 0.012). The glenoid width and surface area restoration by distal clavicle bone blocks were equivalent to TL (p = 0.058 and p = 0.103, respectively).

Discussion

The CAL technique restored higher percentages of glenoid surface area than TL but has less depth, which may increase fracture risk during screw insertion. The distal clavicle bone block is a suitable substitute to TL as it was equivalent regarding glenoid width and surface area restoration.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Open Bone Augmentation Solutions for the Failed Shoulder Stabilization

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

Arthroscopic Management of the Contact Athlete with Anterior Instability

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

iPhone-Based Cartilage Topography Scanning Yields Similar Results to Computed Tomography Scanning

Purpose

To investigate the feasibility and accuracy of 3-dimensional (3D) iPhone scans using commercially available applications compared with computed tomography (CT) for mapping chondral surface topography of the knee.

Methods

Ten cadaveric dysplastic trochleae, 16 patellae, and 24 distal femoral condyles (DFCs) underwent CT scans and 3D scans using 3 separate optical scanning applications on an iPhone X. The 3D surface models were compared by measuring surface-to-surface least distance distribution of overlapped models using a validated 3D-3D registration volume merge method. The absolute least mean square distances for the iPhone-generated models from each scanning application were calculated in comparison to CT models using a point-to-surface distance algorithm allowing regional "inside/outside" measurement of the absolute distance between models.

Results

Only 1 of the 3 scanning applications created models usable for quantitative analysis. Overall, there was a median absolute least mean square distance between the usable model and CT-generated models of 0.18 mm. The trochlea group had a significantly lower median absolute least mean square distance compared with the DFC group (0.14 mm [interquartile range, 0.13-0.17] vs 0.19 mm [0.17-0.25], P = .002). iPhone models were smaller compared with CT models (negative signed distances) for all trochleae, 83% of DFCs, and 69% of patellae.

Conclusions

In this study, we found minimal differences between a 3D iPhone scanning application and conventional CT scanning when analyzing surface topography.

Clinical Relevance

Emerging 3D iPhone scanning technology can create accurate, inexpensive, real-time 3D models of the intended target. Surface topography evaluation may be useful in graft selection during surgical procedures such as osteochondral allograft transplantation.

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

Background

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

Methods

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

Results

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

Conclusion

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

Treatment of Shoulder Cartilage Defects in Athletes

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

Sutures, Screws, Buttons, and Anchors: A Review of Current Bone Graft Fixation Devices for Glenoid Bone Loss in the Unstable Shoulder

PURPOSE OF REVIEW

Anterior shoulder instability is associated with concomitant injury to several stabilizing structures of the shoulder, including glenoid bone loss. While instability is most common in young athletes and patients with predisposing conditions of hyperlaxity, recurrent shoulder instability can occur throughout various age ranges and may lead to longer term effects including pain and shoulder arthritis. Glenoid bone loss exceeding certain thresholds is generally treated by glenoid reconstruction via bone block augmentation to adequately stabilize the glenohumeral joint. These procedures increase the width of the articular surface on which the humeral head can translate before dislocation and, based on the procedure performed, provide a sling effect via the conjoined tendon, and increase tension to support the anterior capsule. The purpose of this review is to summarize the available literature regarding bone block fixation techniques.

RECENT DEVELOPMENTS

Various fixation techniques have been utilized to secure bone block transfers. Though screw fixation has traditionally been used for bone block fixation, suture buttons, suture anchors, and all-suture techniques have been utilized in attempts to avoid complications associated with the use of screws. Biomechanical studies report variable force-resistance, displacement, and mode of failure when comparing screw to suture button-based fixation of glenoid bone blocks. Clinical and radiographic studies have shown these novel suture-based techniques to be comparable, and in some cases advantageous, to traditional screw fixation techniques. While screw fixation has long been the standard of care in glenoid bone block procedures, it is associated with high complication rates, leading surgeons to endeavor toward new fixation techniques. In available biomechanical studies, screw fixation has consistently demonstrated high maximal load-to-failure and displacement with cyclic loading. Studies have reported similar clinical and radiographic outcomes in both screw and suture-based fixation methods, with evidence of reduced bone resorption with suture fixation. While suture button fixation is associated with a higher rate of recurrent instability, overall complication rates are low. Future research should address biomechanical shortcomings of suture-based fixation techniques and continue to assess long-term follow-up of patients treated with each fixation method.

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

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

The Subscapularis-Sparing "Flipped Latarjet" Procedure

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Controlled laboratory study.

METHODS

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

RESULTS

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

CONCLUSION

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

Free Bone Block Procedures for Glenoid Reconstruction in Anterior Shoulder Instability

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

A Systematic Review of Screw and Suture Button Glenoid Augmentation Constructs

Background

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

Purpose

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

Study Design

Systematic review.

Methods

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

Results

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

Conclusion

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

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

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

Acromion and Distal Clavicle Grafts for Arthroscopic Glenoid Reconstruction

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bankart repair with subscapularis augmentation: A case control study

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

Management of Shoulder Instability in Patients with Seizure Disorders

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Background

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

Indications

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

Technique Description

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

Results

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

Discussion/Conclusion

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

Patient Consent Disclosure Statement

The author(s) attest that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Surgeon variation in glenoid bone reconstruction procedures for shoulder instability

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Controlled laboratory study.

METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL RELEVANCE

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

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

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

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

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

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

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

Description

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

Alternatives

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

Rationale

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

Expected Outcomes

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

Important Tips

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

Acronyms & Abbreviations

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

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

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

A review of bone grafting techniques for glenoid reconstruction

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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