Applying the Glenoid Track Concept in the Management of Patients with Anterior Shoulder Instability

Beyond guesswork: how accurate are surgeons at determining the degree of glenoid bone loss in instability surgery?

Background

Accurate measurement of glenoid bone loss (GBL) is critical to preoperative planning in cases of recurrent shoulder instability. The concept of critical bone loss has been established with a value of GBL >13.5% being associated with higher failure rate following arthroscopic Bankart Repair. Advanced imaging, such as magnetic resonance imaging (MRI) scans, can be used to quantify GBL prior to surgery using the best-fit circle technique. Surgeons have traditionally relied on visual inspection of the MRI scan preoperatively or on visual inspection of the glenoid at the time of arthroscopy to determine whether GBL is present. The purpose of this study is to determine if 3 fellowship-trained shoulder surgeons could adequately quantify GBL without using best-fit circle measurements on MRI.

Methods

A retrospective review was performed which included 122 patients over an 8-year period that had an arthroscopic Bankart repair performed by 3 fellowship-trained surgeons. In all patients, preoperative MRI scans were retrospectively measured using best-fit circle technique to determine true GBL and compare that to the surgeons' preoperative and intraoperative estimation of GBL.

Results

GBL was correctly identified in only 36% (18/50) of patients when the preoperative best-fit circle measurements were not made. Critical bone loss was missed in 9.8% (12/122) of patients in the study group. The estimated mean bone loss in that group by visual inspection was 11.3% compared to 16% true bone loss measured on MRI. Even in the 18 patients with some identified bone loss prior to surgery, critical bone loss was missed in 6 patients when using visual inspection of the MRI or intraoperative inspection alone.

Conclusion

Simple visual inspection of glenoid images on MRI scan and visual inspection of the glenoid at the time of surgery are inaccurate in determining the true extent of GBL especially in cases of subtle bone deficiency. Preoperative planning is dependent on the exact degree of bone deficiency and measurement on the MRI scan using the best-fit circle technique is recommended in all cases of instability surgery.

Two Cases of Anterior Shoulder Dislocation and Fracture Secondary to Generalized Tonic-Clonic Seizure

Dislocation of the glenohumeral joint secondary to generalized tonic-clonic seizures is well documented in the medical literature, with posterior dislocation being most commonly described. Still, these occurrences tend to be rare and affect a minority of patients, and fractures associated with dislocations after seizures are even less common. As such, the management of these injuries tends to be quite varied, and there is a paucity of documented cases in the literature. Here, we would like to present two rare cases of anterior shoulder dislocation secondary to seizures, with one patient also sustaining a fracture of the proximal humerus. We would also like to discuss the management and outcomes that have been achieved, since these cases tend to occur in a small number of epileptic patients.

Arthroscopic Bankart with remplissage results in lower rates of recurrent instability with similar range of motion compared to isolated arthroscopic Bankart for anterior glenohumeral instability: A systematic review and meta-analysis

PURPOSE

The addition of the remplissage procedure to an arthroscopic Bankart procedure has been shown to improve clinical outcomes, yet at the expense of potentially decreasing shoulder range of motion. The purpose of this study was to assess recurrent instability, range of motion, functional outcomes and rates of return to sport outcomes in patients undergoing an isolated arthroscopic Bankart repair compared to those undergoing arthroscopic Bankart repair in addition to the remplissage procedure.

METHODS

According to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, a search was conducted using three databases (MEDLINE/OVID, EMBASE and PubMed). Retrieved studies were screened based on predefined inclusion and exclusion criteria for comparative studies. Data were extracted and meta-analysis performed using a random-effects model.

RESULTS

A total of 16 studies (13 level III studies, 2 level II studies and 1 level I) were included with a total of 507 and 704 patients in the Bankart plus remplissage and isolated Bankart repair groups, respectively. No studies reported glenoid bone loss of >20% with the least percentage of glenoid bone loss reported among studies being <1%. There was a significantly increased rate of recurrent dislocations (odds ratio [OR] = 4.22, 95% confidence interval [CI]: 2.380-7.48, p < 0.00001) and revision procedures (OR = 3.36, 95% CI: 1.52-7.41, p = 0.003) in the isolated Bankart repair group compared to the Bankart plus remplissage group. Additionally, there were no significant differences between groups in terms of external rotation at side (n.s.), in abduction (n.s.) or at forward flexion (n.s.) at final follow-up. Furthermore, return to preinjury level of sport favoured the Bankart plus remplissage group (OR = 0.54, 95% CI: 0.35-0.85, p = 0.007).

CONCLUSION

Patients undergoing arthroscopic Bankart plus remplissage for anterior shoulder instability have lower rates of recurrent instability, higher rates of return to sport, and no significant difference in range of motion at final follow-up when compared to an isolated arthroscopic Bankart repair. Further large, prospective studies are needed to further determine which patients and degree of bone loss would benefit most from augmentation with the remplissage procedure.

LEVEL OF EVIDENCE

Level III.

Glenoid Track Assessment at Imaging in Anterior Shoulder Instability: Rationale and Step-by-Step Guide

Anterior shoulder dislocation is the most common form of joint instability in humans, usually resulting in soft-tissue injury to the glenohumeral capsuloligamentous and labral structures. Bipolar bone lesions in the form of fractures of the anterior glenoid rim and posterolateral humeral head are often associated with anterior shoulder dislocation and can be a cause or result of recurrent dislocations. Glenoid track assessment is an evolving concept that incorporates the pathomechanics of anterior shoulder instability into its management. Currently widely endorsed by orthopedic surgeons, this concept has ramifications for prognostication, treatment planning, and outcome assessment of anterior shoulder dislocation. The glenoid track is the contact zone between the humeral head and glenoid during shoulder motion from the neutral position to abduction and external rotation. Two key determinants of on-track or off-track status of a Hill-Sachs lesion (HSL) are the glenoid track width (GTW) and Hill-Sachs interval (HSI). If the GTW is less than the HSI, an HSL is off track. If the GTW is greater than the HSI, an HSL is on track. The authors focus on the rationale behind the glenoid track concept and explain stepwise assessment of the glenoid track at CT or MRI. Off-track to on-track conversion is a primary goal in stabilizing the shoulder with anterior instability. The key role that imaging plays in glenoid track assessment warrants radiologists' recognition of this concept along with its challenges and pitfalls and the production of relevant and actionable radiology reports for orthopedic surgeons-to the ultimate benefit of patients. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Surgical treatment of shoulder instability in active-duty service members with subcritical glenoid bone loss: Bankart vs. Latarjet

INTRODUCTION

Subcritical bone loss has been identified as a risk factor for potentially inferior outcomes following typical arthroscopic soft tissue repair. One alternative that has been presented as an option for patients with bone loss is the Latarjet, an ipsilateral coracoid transfer to the anteroinferior glenoid. The purpose of this study is to compare the outcomes between the arthroscopic Bankart repair and the open Latarjet for the treatment of anterior shoulder instability in patients with subcritical bone loss. We hypothesize that the open Latarjet will provide higher patient-reported outcome measure scores and lower rates of dislocation.

METHODS

A retrospective cohort comparison of patients with anterior glenohumeral instability procedures was performed. Inclusion criteria included symptomatic anterior shoulder instability, subcritical glenoid bone loss (13.5%-24%), surgical treatment with arthroscopic Bankart repair or open Latarjet, and minimum follow-up of 2 years. Outcomes included recurrent instability (defined as postoperative dislocation or subjective subluxation), permanent physical restrictions, Western Ontario Shoulder Index (WOSI), and Single Assessment Numeric Evaluation (SANE) scores.

RESULTS

Forty-seven patients were included, 25 of whom underwent an arthroscopic Bankart repair and 23 patients an open Latarjet. The average bone loss was 17.8% and 19.3%, respectively. Overall, 8 patients experienced recurrent instability, 6 in the arthroscopic Bankart group and 2 in the open Latarjet group (P = .162). The average postoperative SANE score for arthroscopic Bankart group was 48% and for the open Latarjet group, 84% (P < .001). The average postoperative WOSI score for the arthroscopic Bankart group was 53.6% and for the open Latarjet group, 67.9% (P = .069). There were significantly more patients placed on permanent physical restrictions in the arthroscopic Bankart repair group (16) compared with open Latarjet (3) (P < .001).

CONCLUSION

In patients with subcritical glenoid bone loss (defined as 13.5%-24%), patients treated with an open Latarjet have insignificantly higher SANE and WOSI scores and lower permanent physical restrictions than patients treated with an arthroscopic Bankart repair. We found no statistically significant difference in recurrent instability rates between the open Latarjet and arthroscopic Bankart repair (P = .162).

The Glenoid Track Paradigm Does Not Reliably Affect Military Surgeons’ Approach to Managing Shoulder Instability

Purpose

To report the frequencies of surgical stabilization procedures performed by military shoulder surgeons and to use decision tree analysis to describe how bipolar bone loss affects surgeons' decision to perform arthroscopic versus open stabilization procedures.

Methods

The Military Orthopaedics Tracking Injuries and Outcomes Network (MOTION) database was queried for anterior shoulder stabilization procedures from 2016 to 2021. A nonparametric decision tree analysis was used to generate a framework for classifying surgeon decision making based on specified injury characteristics (labral tear location, glenoid bone loss [GBL], Hill-Sachs lesion [HSL] size, and on-track vs off-track HSL).

Results

A total of 525 procedures were included in the final analysis, with a mean patient age of 25.9 ± 7.2 years and a mean GBL percentage of 3.6% ± 6.8%. HSLs were described based on size as absent (n = 354), mild (n = 129), moderate (n = 40), and severe (n = 2) and as on-track versus off-track in 223 cases, with 17% (n = 38) characterized as off-track. Arthroscopic labral repair (n = 428, 82%) was the most common procedure, whereas open repair (n = 10, 1.9%) and glenoid augmentation (n = 44, 8.4%) were performed infrequently. Decision tree analysis identified a GBL threshold of 17% or greater that resulted in an 89% probability of glenoid augmentation. Shoulders with GBL less than 17% combined with a mild or absent HSL had a 95% probability of an isolated arthroscopic labral repair, whereas a moderate or severe HSL resulted in a 79% probability of arthroscopic repair with remplissage. The presence of an off-track HSL did not contribute to the decision-making process as defined by the algorithm and data available.

Conclusions

Among military shoulder surgeons, GBL of 17% or greater is predictive of a glenoid augmentation procedure whereas HSL size is predictive of remplissage for GBL less than 17%. However, the on-track/off-track paradigm does not appear to affect military surgeons' decision making.

Level of Evidence

Level III, retrospective cohort study.

Consideration May Be Given to Lowering the Threshold for the Addition of Remplissage in Patients With Subcritical Glenoid Bone Loss Undergoing Arthroscopic Bankart Repair

Purpose

Treatment for patients with anterior glenohumeral instability with subcritical bone loss is evolving. The purpose of this study was to compare 2-year outcomes of arthroscopic Bankart repair with and without Hill–Sachs remplissage in patients with <15% glenoid bone loss.

Methods

A multicenter retrospective study was performed on a consecutive series of patients who underwent primary isolated arthroscopic Bankart repair (IBR) or arthroscopic Bankart repair with remplissage (REMP) by 4 shoulder specialists between 2013 and 2019. Range of motion (ROM) and patient-reported outcomes (PROs) were collected at baseline and 2 years postoperative: Western Ontario Shoulder Instability Index, Single Assessment Numeric Evaluation, and visual analog scale for pain. Recurrence, return to sport, satisfaction, complications, and revisions also were reviewed.

Results

A total of 123 patients were available, including 75 IBR and 48 REMP. Baseline demographics, activity, ROM, and PROs were similar. Mean glenoid bone loss (2.5% vs 6.1%: P < .001) was greater in REMP, although the number of on-track lesions was similar (98.7% vs 93.8%: P = .298). WOSI scores were improved for REMP (196.5 vs 42.7: P = .004), but otherwise no difference in postoperative PROs or ROM. Differences between cohorts did not reach significance in return to sport (73% vs 83%: P = .203), recurrence (9.3% vs 2.1%: P = .148), or revisions (6.8% vs 2.1%: P = .403). For on-track lesions there were 6 recurrences in IBR (6 of 74; 8.1%) and 1 recurrence in REMP (1 of 45; 2.2%).

Conclusions

Despite slightly worse pathology, patients with subcritical bone loss who undergo REMP experience similar short-term postoperative function to isolated IBR. Recurrence, revision, and return to sport favored REMP but this study was underpowered to show statistical significance. Recurrence was common following IBR, despite subcritical glenoid bone loss and primarily on-track lesions, suggesting that REMP can be considered in on-track lesions.

Level of Evidence

III, retrospective comparative study.

High Rate of Return to Work by 3 Months Following Latarjet for Anterior Shoulder Instability

PURPOSE

To evaluate the rate and duration of return to work in patients undergoing Latarjet for failed soft-tissue stabilization or glenoid bone loss.

METHODS

Consecutive patients undergoing Latarjet from 2005 to 2015 at our institution were retrospectively reviewed at a minimum of 2 years postoperatively. Patients completed a standardized and validated work questionnaire, Western Ontario Shoulder Instability Index Survey, and a satisfaction survey.

RESULTS

Of 89 eligible patients who had Latarjet, 67 patients (75.3%) responded to the questionnaire, of whom 51 patients (76.1%) were employed within 3 years before surgery (mean age: 29.9 ± 11.8 years; mean follow-up: 54.6 ± 11.9 months) and had an average glenoid bone loss of 14.5 ± 6.1%. Fifty patients (98.0%) returned to work by 2.7 ± 3.0 months postoperatively; 45 patients (88.2%) patients returned to the same level of occupational intensity. Those who held sedentary, light, moderate, or heavy intensity occupations returned to their previous occupation at a rate of 100.0%, 93.3%, 90.0%, and 66.7% (P = .2) at a duration of 1.2 ± 1.6 months, 1.8 ± 1.9 months, 3.1 ± 3.5 months, and 6.5 ± 4.1 months (P = .001), respectively. The average postoperative Western Ontario Shoulder Instability Index score was 70.9 ± 34.2. Fifty patients (98.0%) noted at least "a little improvement" in their quality of life following surgery, with 35 patients (68.6%) noting great improvement. Furthermore, 49 patients (96.1%) reported being satisfied with their procedure, with 25 patients (49.0%) reporting being very satisfied. Four patients (7.8%) returned to the operating room, with 1 patient (2.0%) requiring arthroscopic shoulder stabilization.

CONCLUSIONS

Approximately 98% of patients who underwent Latarjet returned to work by 2.7 ± 3.0 months postoperatively. Patients with greater-intensity occupations had a longer duration of absence before returning to their preoperative level of occupational intensity. Information regarding return to work is imperative in preoperative patient consultation to manage expectations.

LEVEL OF EVIDENCE

IV, case series.

Validação clínica do conceito de glenoid track na instabilidade glenoumeral anterior

Objective  To evaluate the correlation of the glenoid track and glenoidal bone loss with the recurrence dislocation rate and the Rowe score.

Methods  Retrospective study that assessed the glenoid track and glenoidal bone loss through preoperative magnetic resonance imaging. Patients undergoing primary arthroscopic repair of anterior Bankart were included. Patients with glenoidal bone loss greater than 21%, rotator cuff tear, scapular waist fracture, and posterior or multidirectional instability were not included. Rowe score were the primary outcome, and the recurrence rate was the secondary outcome.

Results  One hundred and two patients were included. Postoperative recurrent instability was reported by 8 patients (7.8%). Four patients (50%) in the group with recurrence presented glenoidal bone loss greater than 13.5% against 24 (25.5%) in the group without recurrence ( p  = 0.210), with a negative predictive value of 94.6%. Three patients (37.5%) in the recurrence group were considered off-track, against 13 (13.8%) in the group without recurrence ( p  = 0.109), with a negative predictive value of 94.2%. Patients with absolute glenoid track value ≤ 1.5 mm had worse results in relation to the recurrence group, with 6 patients (75%) presenting recurrence ( p  = 0.003).

Conclusion  Off-track injury and glenoidal bone loss greater than the subcritical are not related to the recurrence rate and Rowe score, despite the high negative predictive value. The cut of the absolute value of the glenoid track at 1.5 mm had a significant relationship with the recurrence rate.

Influence of the glenoid track and glenoid bone loss on the apprehension test for shoulder instability

Background

The investigation of Hill-Sachs and bony Bankart lesions continues to evolve. Patients with large bone lesions can present with a positive apprehension test even at ranges below 45° of abduction and external rotation of the shoulder. Modern concepts, such as glenoid track and quantification of glenoid bone loss, have been increasingly applied to shoulder instability. The objective of this study was to assess the correlation of the glenoid track and glenoid bone loss on the apprehension test conducted at 0°, 45°, and 90° of shoulder abduction.

Methods

Ninety-four shoulders of 90 patients with anterior glenohumeral instability were retrospectively assessed. The apprehension test was performed at 0°, 45°, and 90° of shoulder abduction. Computed tomography, magnetic resonance imaging, or magnetic resonance arthrogram scans were performed to calculate the glenoid track and glenoid bone loss. A descriptive analysis, an association analysis, and a logistic regression analysis were used in this study. Logistic regression analysis was used to assess the influence of glenoid track and glenoid bone loss when the apprehension test was positive in lower degrees of abduction.

Results

A positive apprehension test at 0°, 45°, and 90° of abduction revealed significant association with off-track lesions, glenoid bone losses greater than 13.5%, and bipolar bone lesions. Shoulders classified as off-track were 36.4 times more likely to test positive at 0°, 45°, and 90° than on-track shoulders. The logistic regression analysis revealed that the positive apprehension test at 0°, 45°, and 90° of abduction seems to be more influenced by off-track lesions than by glenoid bone loss greater than the 13.5% threshold.

Conclusion

Shoulders with a positive apprehension test at 0°, 45°, and 90° are significantly associated with off-track lesions, bipolar bone lesions, and glenoid bone losses greater than 13.5%.

Optimization of the Algorithm for Choosing the Surgical Treatment of Anterior Recurrent Instability of the Shoulder Joint

Introduction. Chronic recurrent instability of the shoulder joint is a frequent outcome of conservative treatment oftraumatic dislocation of the shoulder (2.8–30 % of cases). Preoperative examination largely determines the outcome of surgical treatment of this pathology.

The aim of the study was to provide a clinical assessment of the developed algorithm for the surgical treatment of patients with recurrent anterior shoulder joint instability. Materials and methods. The results of treatment of 98 patients with recurrent anterior shoulder joint instability were studied. Preoperative examination included clinical tests, MRI or CT with calculation of bone loss. Fifty-six patients (57.1 %) underwent Bankart operation, 14 patients (14.3 %) – Latarjet operation. Twenty-three patients (23.5 %) underwent Bankart + Remplissage surgery, and 5 (5.1 %) – Latarjet + remplissage. The result was assessed on the ROWE scale.

Results. Bone defects significant in the formation of instability (“glenoid off track”) were found in 19.4 % of patients, and “glenoid on track” – in 80.6 %. According to the proposed algorithm for treating patients with anterior recurrent instability of the shoulder joint, the “glenoid off track” state was an indication for Latarjet surgery. When “glenoid on track” was used, indications for Bankart operation were displayed. The remplissage procedure was indicated in case of the presence of a Hill-Sachs grade 3 defect or the presence of hyperelasticity of the tissues of the shoulder joint. The mean ROWE score for the entire group of patients before surgery was 41.5 ± 12.8 points, and 15 months after sur gery – 94.9 ± 3.4 points. Two recurrent dislocations were revealed, one of which was associated with repeated trauma, and the other – with an incorrect choice of stabilization technique. One complication (axillary nerve neuropathy) was observed, which was arrested conservatively.

Conclusions. The proposed algorithm allowed us to obtain positive results in 97.9 % of cases. 

Optimization of the Algorithm for Choosing the Surgical Treatment of Anterior Recurrent Instability of the Shoulder Joint

Introduction. Chronic recurrent instability of the shoulder joint is a frequent outcome of conservative treatment oftraumatic dislocation of the shoulder (2.8–30 % of cases). Preoperative examination largely determines the outcome of surgical treatment of this pathology.

The aim of the study was to provide a clinical assessment of the developed algorithm for the surgical treatment of patients with recurrent anterior shoulder joint instability. Materials and methods. The results of treatment of 98 patients with recurrent anterior shoulder joint instability were studied. Preoperative examination included clinical tests, MRI or CT with calculation of bone loss. Fifty-six patients (57.1 %) underwent Bankart operation, 14 patients (14.3 %) – Latarjet operation. Twenty-three patients (23.5 %) underwent Bankart + Remplissage surgery, and 5 (5.1 %) – Latarjet + remplissage. The result was assessed on the ROWE scale.

Results. Bone defects significant in the formation of instability (“glenoid off track”) were found in 19.4 % of patients, and “glenoid on track” – in 80.6 %. According to the proposed algorithm for treating patients with anterior recurrent instability of the shoulder joint, the “glenoid off track” state was an indication for Latarjet surgery. When “glenoid on track” was used, indications for Bankart operation were displayed. The remplissage procedure was indicated in case of the presence of a Hill-Sachs grade 3 defect or the presence of hyperelasticity of the tissues of the shoulder joint. The mean ROWE score for the entire group of patients before surgery was 41.5 ± 12.8 points, and 15 months after sur gery – 94.9 ± 3.4 points. Two recurrent dislocations were revealed, one of which was associated with repeated trauma, and the other – with an incorrect choice of stabilization technique. One complication (axillary nerve neuropathy) was observed, which was arrested conservatively.

Conclusions. The proposed algorithm allowed us to obtain positive results in 97.9 % of cases. 

Computed Tomography-Based Preoperative Planning Provides a Pathology and Morphology-Specific Approach to Glenohumeral Instability With Bone Loss

PURPOSE

To use computed tomography (CT) to determine a reproducible method of coracoid measurement to compare the ability of the classic Latarjet technique and the congruent arc modification (CAM) to restore native glenoid diameter and to develop a preoperative planning algorithm for glenoid restoration with a goal of achieving an on-track shoulder.

METHODS

Coracoid dimensions were measured on multiplanar reconstructed shoulder CT scans of patients aged 18 to 45 years obtained between December 1, 2019, and March 13, 2020. Patients were excluded if CT demonstrated osteophyte formation, glenoid dysplasia, coracoid fracture, or tumor. The proportion of glenoid diameter able to be restored using classic Latarjet technique and CAM were calculated. A treatment algorithm was proposed considering the amount of bone loss present and coracoid dimensions.

RESULTS

Coracoid dimensions of 117 consecutive patients were measured and varied considerably (length: 17.5-31.8 mm, width: 9.1-20.5 mm, thickness: 6.1-15.7 mm). While most patients had harvestable coracoid length ≥20 mm (male: 96.3% vs female: 94.4%, P = .65), only 27.8% of female patients had coracoid thickness ≥10 mm. When comparing Latarjet techniques, there was no difference in the proportion of patients in whom 30% glenoid diameter could be fully restored, but CAM was able to restore at least 35% in more male and female patients (98.8% vs 79.0% and 100% vs 61.1%, respectively, P = .00001). Intra- and inter-rater reliability was excellent ( intraclass correlation coefficient ≥0.950 for all dimensions).

CONCLUSIONS

We describe a reliable method of measuring coracoid dimensions for preoperative planning of glenoid restoration. The classic Latarjet technique reliably restores the glenoid anteroposterior diameter with bone loss of up to 30%. The majority of female patients have coracoid thickness <10 mm, which may increase the risk of graft fracture when using CAM. The decision to use the classic Latarjet technique or CAM considers each individual's glenoid and coracoid dimensions with a goal of achieving an on-track shoulder.

CLINICAL RELEVANCE

Our reliable method of coracoid measurement demonstrated the differing abilities of the classic Latarjet and CAM to restore the native glenoid diameter. An evidence-based algorithm using these measurements was developed to assist in preoperative planning for glenohumeral instability in the setting of bone loss, with a goal of achieving an on-track shoulder. Alternative techniques may be considered if an on-track shoulder cannot be achieved with Latarjet.

Failure Rates After Revision Arthroscopic Stabilization for Recurrent Anterior Shoulder Instability Based on Anterior Capsulolabral Complex Conditions

Background:

A labral retear is an important contributing factor to surgical failure after arthroscopic soft tissue stabilization for recurrent anterior shoulder instability. However, surgeons frequently encounter poor tissue conditions in the anterior capsule, such as capsular tears, during revision surgery.

Purpose:

To analyze the clinical outcomes and failure rates of revision arthroscopic stabilization after failed Bankart repair based on the tissue conditions of the anterior capsule and the labrum. Outcomes were compared for revision after failed Bankart repair because of a labral retear versus a healed labrum but with capsular tears.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 55 patients who underwent revision arthroscopic stabilization after failed Bankart repair were included. Revision surgery was indicated if patients had a history of recurrent instability with positive apprehension test results, regardless of magnetic resonance imaging (MRI) findings of a labral retear. Patients were allocated into 2 groups based on arthroscopic findings at the time of revision surgery: group 1 consisted of patients who had a healed labrum with definite anterior capsular tears, and group 2 comprised patients who had labral retears without capsular tears. Clinical outcomes were assessed using the American Shoulder and Elbow Surgeons score, Rowe score, and surgical failure rate.

Results:

Overall, 10 patients were included in group 1, and 45 patients were included in group 2. No capsular tears were detected on preoperative MRI or magnetic resonance arthrography scans in either group, whereas all patients in group 2 had evidence of anterior labral retears on imaging scans. After revision surgery, 9 patients (16.4%) showed surgical failure by 25.6 months postoperatively. Patients in group 1 had a significantly higher surgical failure rate than did those in group 2 (4 patients [40.0%] vs 5 patients [11.1%], respectively; P = .04). The incidence of capsular tears was significantly higher in patients with surgical failure versus those without surgical failure (44.4% vs 13.0%, respectively; P = .04).

Conclusion:

A capsular tear of the anterior capsulolabral complex was an important indicator for surgical failure after revision arthroscopic stabilization. If patients demonstrate symptomatic instability after arthroscopic soft tissue stabilization without evidence of labral retears on imaging scans, an anterior capsular tear should be considered as a possible factor for recurrence.

Evolving Concepts in the Management of Shoulder Instability

BACKGROUND

Shoulder instability exists on a spectrum ranging from subtle subluxation and pain to dislocation and can be the result of a traumatic event or repetitive microtrauma. Shoulder instability can result in significant disability and often requires surgical intervention, especially amongst younger, active patient populations. The optimal treatment of shoulder instability depends on the degree of instability and concomitant pathology involving the labrum, capsule, and bony anatomy of the glenoid and humeral head. Even with surgical intervention, recurrent instability remains a relatively common and difficult problem to address.

PURPOSE

With a focus on anterior instability, the purpose of this review article is to discuss the current assessment and treatment of shoulder instability, and highlight current and future treatment modalities, as well as to identify current trends and deficiencies in our current management. We also provide an algorithm for the surgical treatment of anterior shoulder instability.

METHODS

Literature databases were extensively searched for recent articles related to the mechanism, diagnosis, and treatment of shoulder instability to comprise a comprehensive review.

CONCLUSION

Although there are multiple treatment modalities available for shoulder instability, such as nonoperative management, open and arthroscopic Bankart repair, Latarjet procedures, and remplissage, orthopaedic surgeons continue to learn about the most appropriate method of management as increasing long-term outcomes become available.

Anterior Glenohumeral Instability in the Adolescent Athlete

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

Surgical treatment for recurrent shoulder instability: factors influencing surgeon decision making

BACKGROUND

The optimal surgical approach for recurrent anterior shoulder instability remains controversial, particularly in the face of glenoid and/or humeral bone loss. The purpose of this study was to use a contingent-behavior questionnaire (CBQ) to determine which factors drive surgeons to perform bony procedures over soft tissue procedures to address recurrent anterior shoulder instability.

METHODS

A CBQ survey presented each respondent with 32 clinical vignettes of recurrent shoulder instability that contained 8 patient factors. The factors included (1) age, (2) sex, (3) hand dominance, (4) number of previous dislocations, (5) activity level, (6) generalized laxity, (7) glenoid bone loss, and (8) glenoid track. The survey was distributed to fellowship-trained surgeons in shoulder/elbow or sports medicine. Respondents were asked to recommend either a soft tissue or bone-based procedure, then specifically recommend a type of procedure. Responses were analyzed using a multinomial-logit regression model that quantified the relative importance of the patient characteristics in choosing bony procedures.

RESULTS

Seventy orthopedic surgeons completed the survey, 33 were shoulder/elbow fellowship trained and 37 were sports medicine fellowship trained; 52% were in clinical practice ≥10 years and 48% <10 years; and 95% reported that the shoulder surgery made up at least 25% of their practice. There were 53% from private practice, 33% from academic medicine, and 14% in government settings. Amount of glenoid bone loss was the single most important factor driving surgeons to perform bony procedures over soft tissue procedures, followed by the patient age (19-25 years) and the patient activity level. The number of prior dislocations and glenoid track status did not have a strong influence on respondents' decision making. Twenty-one percent glenoid bone loss was the threshold of bone loss that influenced decision toward a bony procedure. If surgeons performed 10 or more open procedures per year, they were more likely to perform a bony procedure.

CONCLUSION

The factors that drove surgeons to choose bony procedures were the amount of glenoid bone loss with the threshold at 21%, patient age, and their activity demands. Surprisingly, glenoid track status and the number of previous dislocations did not strongly influence surgical treatment decisions. Ten open shoulder procedures a year seems to provide a level of comfort to recommend bony treatment for shoulder instability.

A lower Instability Severity Index score threshold may better predict recurrent anterior shoulder instability after arthroscopic Bankart repair: a systematic review

Importance

The Instability Severity Index (ISI) score was developed to evaluate a patient’s risk of recurrent shoulder instability following arthroscopic Bankart repair. While patients with an ISI score of >6 were originally recommended to undergo an open procedure (ie, Latarjet) to minimise the risk of recurrence, recent literature has called into question the utility of the ISI score.

Objective

The purpose of this systematic review was to evaluate the efficacy of the ISI score as a tool to predict postoperative recurrence among patients undergoing arthroscopic Bankart procedures.

Evidence review

Articles were included if study participants underwent arthroscopic Bankart repair for anterior shoulder instability and reported postoperative recurrence by ISI score at a minimum of 2 years of follow-up. Methodological study quality was assessed using the Methodological Index for Non-Randomized Studies criteria. Pearson’s χ2 test was used to compare recurrence rates among patients above and below an ISI score of 4. Sensitivity, specificity, mean ISI scores and predictive value of individual factors of the ISI score were qualitatively reviewed.

Findings

Four studies concluded the ISI score was effective in predicting postoperative recurrence following arthroscopic Bankart repair; however, these studies found threshold values lower than the previously proposed score of >6 may be more predictive of recurrent instability. A pooled analysis of these studies found patients with an ISI score <4 to experience significantly lower recurrence rates when compared with patients with a score ≥4 (6.3% vs 26.0%, p<0.0001). The mean ISI score among patients who experienced recurrent instability was also significantly higher than those who did not.

Conclusions and relevance

The ISI score as constructed by Balg and Boileau may have clinical utility to help predict recurrent anterior shoulder instability following arthroscopic Bankart repair. However, this review found the threshold values published in their seminal article to be insufficient predictors of recurrent instability. Instead, a lower score threshold may provide as a better predictor of failure. The paucity of level I and II investigations limits the strength of these conclusions, suggesting a need for further large, prospective studies evaluating the predictive ability of the ISI score.

Level of evidence

IV.

Anterior glenohumeral instability: Current review with technical pearls and pitfalls of arthroscopic soft-tissue stabilization

The glenohumeral joint (GHJ) allows for a wide range of motion, but is also particularly vulnerable to episodes of instability. Anterior GHJ instability is especially frequent among young, athletic populations during contact sporting events. Many first time dislocators can be managed non-operatively with a period of immobilization and rehabilitation, however certain patient populations are at higher risk for recurrent instability and may require surgical intervention for adequate stabilization. Determination of the optimal treatment strategy should be made on a case-by-case basis while weighing both patient specific factors and injury patterns (i.e., bone loss). The purpose of this review is to describe the relevant anatomical stabilizers of the GHJ, risk factors for recurrent instability including bony lesions, indications for arthroscopic vs open surgical management, clinical history and physical examination techniques, imaging modalities, and pearls/pitfalls of arthroscopic soft-tissue stabilization for anterior glenohumeral instability.

Distal tibia allograft glenoid reconstruction for shoulder instability: outcomes after lesser tuberosity osteotomy

BACKGROUND

Distal tibia allograft reconstruction of the glenoid in shoulder instability has garnered significant attention over the last decade. Prior studies demonstrate significant improvement in all reported patient outcomes albeit the approach is through a subscapularis split. There have not been prior studies evaluating outcomes after lesser tuberosity osteotomy which provides excellent exposure to the anterior glenoid.We hypothesize there is significant improvement in functional outcomes and no deleterious effects after lesser tuberosity osteotomy for distal tibia allograft reconstruction of the glenoid for shoulder instability.

METHODS

A retrospective review was performed from 2016 of 2019 of patients undergoing distal tibia allograft reconstruction of the glenoid through a lesser tuberosity osteotomy. Patients were indicated if they had recurrent anterior shoulder instability with >20% glenoid bone loss and evidence of an off-track lesion. Clinical, imaging, and operative data were evaluated. Objective follow-up data evaluated at minimum 2 years included radiographs, range of motion, DASH, SANE, VAS, SST, ASES, and Constant scores.

RESULTS

A total of 12 patients were available with average follow-up 28 months, average age 26 years old, and average glenoid bone loss of 33%. The patients demonstrated significant improvement in their clinical outcomes at final follow-up: DASH 42.9-8.9 (P = .004), SANE 32.2-85 (P = .00005), VAS 4.6-1.1 (P = .003), SST 7-11.4 (P = .01), ASES 50.2-90.5 (P = .001), and Constant 37.6-86.2 (P = .01). Range of motion at final follow-up was forward flexion to 161.4° (135-170°), external rotation 49.5° (40-65°), and internal rotation to T12-L1 (T7-L2) vertebral body.

CONCLUSION

The present study demonstrates the effectiveness of a lesser tuberosity osteotomy in exposure of the glenoid for reconstruction with a distal tibia allograft. The functional integrity of the subscapularis is maintained and the patient-reported outcomes are comparable with current literature.

The Hill-Sachs interval to glenoid track width ratio is comparable to the instability severity index score for predicting risk of recurrent instability after arthroscopic Bankart repair

PURPOSE

The purpose of this study was to clinically validate the Hill-Sachs interval to glenoid track width ratio (H/G ratio) compared with the instability severity index (ISI) score for predicting an increased risk of recurrent instability after arthroscopic Bankart repair.

METHODS

A retrospective evaluation was performed using data from patients with anteroinferior shoulder instability who underwent arthroscopic Bankart repair with a follow-up period of at least 24 months. A receiver operating characteristic (ROC) curve was used to determine the optimal cut-off values for the H/G ratio and the ISI score to predict an increased risk of recurrent instability. The area under the ROC curve (AUC) of the two methods and the sensitivity and specificity of their optimal cut-off values were compared.

RESULTS

A total of 222 patients were included, among whom 31 (14.0%) experienced recurrent instability during the follow-up period. The optimal cut-off values for predicting an increased risk of recurrent instability were an H/G ratio of ≥ 0.7 and ISI score of ≥ 4. There were no significant differences between the AUC of the two methods (H/G ratio AUC = 0.821, standard error = 0.035 and ISI score AUC = 0.792, standard error = 0.04; n.s.) nor between the sensitivity and specificity of the optimal cut-off values (n.s. and n.s., respectively).

CONCLUSIONS

The H/G ratio is comparable to the ISI score for predicting an increased risk of recurrent instability after arthroscopic Bankart repair. Surgeons are recommended to consider other strategies to treat anterior shoulder instability if H/G ratio is ≥ 0.7.

LEVEL OF EVIDENCE

III.

Evaluation of the Glenoid Track Tomographic Method in Magnetic Resonance Imaging/Arthro-MRI

Objective  To evaluate and compare the glenoid track method in 3D-reconstructed computed tomography (3D-CT) scans with magnetic resonance imaging (MRI) and/or arthro-MRI.

Methods  Forty-four shoulders with clinical and radiographic diagnosis of traumatic anterior instability were assessed using 3D-CT, MRI, and/or arthro-MRI scans. Glenoid track (GT), Hill-Sachs interval (HSI), and glenoid bone loss (GBL) were determined by a radiologist using 3D-CT images, and classified as on-track/off-track. Three surgeons, blinded to the radiologist's evaluation, performed the same determinations using MRI/arthro-MRI. Descriptive analysis, variance analysis, results disagreement analysis, and receiver operating characteristic (ROC) curves were performed.

Results  Results from the 4 examiners were fully consistent in 61.4% of the cases. Magnetic resonance imaging/arthro-MRI diagnosed off-track injuries with 35 to 65% sensitivity and on-track injuries, with 91.67 to 95.83% specificity. Accuracy ranged from 68.1 to 79.5%. The greatest data divergence occurred for off-track injuries diagnosed by MRI/arthro-MRI. The greatest data variability referred to HSI calculation. Higher HSI and GBL values were associated with greater disagreement among examiners. Hill-Sachs interval values were lower at MRI/arthro-MRI when compared to 3D-CT. Agreement between CT and MRI/arthro-MRI for the GT method was only moderate (kappa value, 0.325–0.579).

Conclusion  Magnetic resonance imaging/arthro-MRI showed low accuracy and moderate agreement for the GT method; as such, it should be used with caution by surgeons.

When to Abandon the Arthroscopic Bankart Repair: A Systematic Review

CONTEXT

Bone loss is a major factor in determining surgical choice in patients with anterior glenohumeral instability. Although bone loss has been described, there is no consensus on glenoid, humeral head, and bipolar bone loss limits for which arthroscopic-only management with Bankart repair can be performed.

OBJECTIVE

To provide guidelines for selecting a more complex repair or reconstruction (in lieu of arthroscopic-only Bankart repair) in the setting of glenohumeral instability based on available literature.

DATA SOURCES

An electronic search of the literature for the period from 2000 to 2019 was performed using PubMed (MEDLINE).

STUDY SELECTION

Studies were included if they quantified bone loss (humeral head or glenoid) in the setting of anterior instability treated with arthroscopic Bankart repair.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Study design, level of evidence, patient demographics, follow-up, recurrence rates, and measures of bone loss (glenoid, humeral head, bipolar).

RESULTS

A total of 14 studies met the inclusion criteria. Of these, 10 measured glenoid bone loss, 5 measured humeral head bone loss, and 2 measured "tracking" without explicit measurement of humeral head bone loss. Measurement techniques for glenoid and humeral head bone loss varied widely. Recommendations for maximum glenoid bone loss for arthroscopic repair were largely <15% of glenoid width in recent studies. Recommendations regarding humeral head loss were more variable (many authors providing only qualitative descriptions) with increasing attention on glenohumeral tracking.

CONCLUSION

It is essential that a standardized method of glenoid and humeral head bone loss measurements be performed preoperatively to assess which patients will have successful stabilization after arthroscopic Bankart repair. Glenoid bone loss should be <15%, and humeral head lesions should be "on track" if an arthroscopic-only Bankart is planned. If there is greater bone loss, adjunct or open procedures should be performed.

Effects of Glenoid and Humeral Bone Defects on Recurrent Anterior Instability of the Shoulder

For proper treatment of recurrent anterior instability of the shoulder with a bone defect, the defect size should be assessed preoperatively with three-dimensional computed tomography or magnetic resonance imaging. In general, the risk of postoperative recurrence of instability is estimated on the basis of preoperative imaging of bipolar bone defects: more than 20%–25% glenoid bone loss and off-track Hill-Sachs lesions have been considered risk factors for recurrence. In patients with a glenoid bone defect more than 20%–25%, a bone graft procedure, such as the Latarjet procedure, is preferred regardless of the glenoid track concept, because compared with arthroscopic stabilization procedure, it provides greater postoperative stability. For patients with a borderline glenoid bone defect (around 20%), surgeons should discuss surgical options with the patients, considering their demand and physical activity level. In addition, the surgeon should take care to prevent postoperative instability and long-term complications. Arthroscopic soft-tissue reconstruction including labral repair and capsular plication combined with the additional remplissage procedure is an anatomical procedure and could be considered as one of the primary treatment methods for patients with glenoid bone defects around 20%. Therefore, treatment strategies for recurrent anterior shoulder instability combined with bone defects should be determined more flexibly on the basis of the patient's individual condition.

How to handle minor and major bone loss in the shoulder? Current concepts

Anterior shoulder instability is a significant problem in orthopaedic surgery. It carries a heavy burden on quality of life, especially in young, active patients. Surgical treatment is therefore often carried out in this population. Several strategies can effectively address this issue. Yet, the consensus is lacking on the parameters which favour one technique over another, especially when bone loss is present. This is because of the complex, dynamic interplay between bone loss on the humeral side (ie, Hill-Sachs lesion) and glenoid bone loss, which is a common occurrence and defined as ‘bipolar’. There is an ongoing debate over the percentage of glenoid bone loss warranting bone block procedures: 13.5–15% is an indicator for such procedures (ie, Latarjet), although this value is still considered controversial and not uniformly accepted. A multitude of other factors (ie, age, sex, level of activity and so on) come into play alongside bipolar bone loss and the weight of each factor has yet to be fully elucidated. Also, refining the algorithm for the right procedure in the right patients will reduce the number of side effects stemming from initial, suboptimal treatment choice. Knowing how to manage previous surgical treatment failure is also key for the treating orthopaedic surgeon, who must be able to address the root cause of failure and react accordingly and effectively. This paper analyses key factors in treatment choice, the current stance of the literature on varying degrees of bone loss and choices on surgical treatment failure, lack of evidence and need for future research.

What Are the Effects of Remplissage on 6-Month Strength and Range of Motion After Arthroscopic Bankart Repair? A Multicenter Cohort Study

BACKGROUND

Patients who have undergone shoulder instability surgery are often allowed to return to sports, work, and high-level activity based largely on a time-based criterion of 6 months postoperatively. However, some believe that advancing activity after surgery should be dependent on the return of strength and range of motion (ROM).

HYPOTHESIS

There will be a significant loss of strength or ROM at 6 months after arthroscopic Bankart repair with remplissage compared with Bankart repair alone.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 38 patients in a prospective multicenter study underwent arthroscopic Bankart repair with remplissage (33 males, 5 females; mean age, 27.0 ± 10.2 years; 82% with ≥2 dislocation events in the past year). Strength and ROM were assessed preoperatively and at 6 months after surgery. Results were compared with 104 matched patients who had undergone Bankart repair without remplissage, although all had radiographic evidence of a Hill-Sachs defect.

RESULTS

At 6 months, there were no patients in the remplissage group with anterior apprehension on physical examination. However, 26% had a ≥20° external rotation (ER) deficit with the elbow at the side, 42% had a ≥20° ER deficit with the elbow at 90° of abduction, and 5% had persistent weakness. Compared with matched patients who underwent only arthroscopic Bankart repair, the remplissage group had greater humeral bone loss and had a greater likelihood of a ≥20° ER deficit with the elbow at 90° of abduction (P = .004). Risk factors for a ≥20° ER deficit with the elbow at 90° of abduction were preoperative stiffness in the same plane (P = .02), while risk factors for a ≥20° ER deficit with the elbow at the side were increased number of inferior quadrant glenoid anchors (P = .003), increased patient age (P = .02), and preoperative side-to-side deficits in ER (P = .04). The only risk factor for postoperative ER weakness was preoperative ER weakness (P = .04), with no association with remplissage (P = .26).

CONCLUSION

Arthroscopic Bankart repair with remplissage did not result in significant strength deficits but increased the risk of ER stiffness in abduction compared with Bankart repair without remplissage at short-term follow-up.

Clinical and functional outcomes of the remplissage technique to repair anterior shoulder dislocation: average 7 years of follow-up

PURPOSE

The purpose of this work is to report mid- to long-term clinical results, recurrence rates and instability following surgery to repair anterior dislocation of the shoulder by the remplissage technique.

METHODS

This was a retrospective case series at a single center with patients with anterior shoulder instability that received surgery using the remplissage technique. Rowe questionnaire, instability complaints, recurrence episodes and return to sport were analyzed.

RESULTS

Of all patients screened, 21 (92.3%) were enrolled and only 2 patients were lost to follow-up. The mean age of the patients at the time of surgery was 27.8y.o., and the mean number of dislocations before surgery was 3.2 episodes. The follow-up average was 83.8 months (range 28-126). No case of postoperative infection was observed. Two patients (9.5%) had recurrent shoulder instability and required reintervention after 18 and 48 months. The average final Rowe score was 92.9 (range 75-100). All patients that played sports before surgery returned to the sport, and 73.7% of them returned to the same activity level.

CONCLUSION

The remplissage technique applied to repair anterior shoulder dislocation with humeral bone loss presents good results regarding clinical scores, shoulder stability and acceptable rates of return to sports, even in a mid- to long-term follow-up.

LEVEL OF EVIDENCE

IV.

Off-track Hill-Sachs lesions do not increase postoperative recurrent instability after arthroscopic Bankart repair with selective Remplissage procedure

PURPOSE

This study aimed to compare clinical outcomes and recurrence rates after arthroscopic Bankart repair with selective Remplissage procedure, between patients with off-track and on-track Hill-Sachs lesions.

METHODS

Patients who underwent arthroscopic Bankart repair with selective Remplissage procedure for recurrent anterior shoulder instability and were followed up for at least 2 years were included. Patients with a glenoid defect greater than 25% were excluded. According to the glenoid track concept, patients were divided into group I (off-track lesions) and group II (on-track lesions). After Bankart repair, an additional Remplissage procedure was performed selectively in patients who sustained engagement of the humeral head. The clinical outcomes and recurrence rates were evaluated.

RESULTS

A total of 193 patients (23 in group I and 170 in group II) were enrolled. No significant differences were found in clinical outcomes (n.s.) or recurrence rates (n.s.) between the two groups, despite larger glenoid defects in group I (group I:17.1 ± 6.1%, and group II:13.0 ± 6.4%, P = 0.003). In all patients, the incidence of off-track lesions was not significantly different according to the occurrence of postoperative recurrence (n.s.), whereas the glenoid defect size showed a significant difference (with recurrence: 17.9 ± 3.9%, and without recurrence: 13.2 ± 6.5%, P = 0.002).

CONCLUSIONS

The presence of an off-track lesion did not alter the clinical outcomes and recurrence rates after arthroscopic Bankart repair with selective Remplissage procedure. The glenoid defect size rather than the presence of an off-track lesion can more reliably predict postoperative recurrence. Arthroscopic Bankart repair with selective Remplissage procedure is considered one surgical option for the treatment of off-track lesions.

LEVEL OF EVIDENCE

III.

A Novel Treatment for Anterior Shoulder Instability: A Biomechanical Comparison Between a Patient-Specific Implant and the Latarjet Procedure

BACKGROUND

Anterior glenohumeral instability with >20% glenoid bone loss is a disorder that can be treated with the Latarjet stabilizing procedure; however, complications are common. The purposes of this study were to (1) evaluate the effect of an anatomic-specific titanium implant produced by 3-dimensional (3D) printing as a treatment option for recurrent shoulder instability with substantial glenoid bone loss and (2) compare the use of that implant with the Latarjet procedure.

METHODS

Ten fresh-frozen cadaveric shoulders (mean age at the time of death, 78 years) were tested in a biomechanical setup with the humerus in 30° of abduction and in neutral rotation. The shoulders were tested under 5 different conditions: (1) normal situation, (2) creation of an anterior glenoid defect, (3) implantation of an anatomic-specific titanium implant produced by 3D printing, and the Latarjet procedure (4) with and (5) without 10 N of load attached to the conjoined tendon. In each condition, the humerus was translated 10 mm anteriorly relative to the glenoid, and the maximum peak translational force that was necessary for this translation was measured.

RESULTS

After creation of the glenoid defect, the mean translational peak force decreased by 30% ± 6% compared with that for the normal shoulder. After restoration of the original glenoid anatomy, the translational force needed to dislocate the humeral head from the glenoid significantly increased compared with that in the defect condition-to 119% ± 16% of normal (p < 0.01) with the 3D-printed anatomic-specific implant and to 121% ± 48% of normal (p < 0.01) following the Latarjet procedure. No significant differences in mean translational force were found between the anatomic-specific implant and the Latarjet procedure (p = 0.72).

CONCLUSIONS

The mean translational peak force needed to dislocate the humerus 10 mm anteriorly on the glenoid was higher after glenoid restoration with the 3D-printed anatomic-specific implant compared with when the glenoid had a 20% surface defect but also compared with when the glenoid was intact. No differences in mean translational peak force were found between the 3D-printed anatomic-specific glenoid implant and the Latarjet procedure, although there was less variability in the 3D-implant condition.

CLINICAL RELEVANCE

Novel 3D-printing technology could provide a reliable patient-specific alternative to solve problems related to traditional treatment methods for shoulder instability.