Does Anchor Placement on the Glenoid Affect Functional Outcome After Arthroscopic Bankart Repair?

Knotless Bioabsorbable Anchors Placed on the Glenoid Face for Arthroscopic Bankart Repair

BACKGROUND

Quantitative analysis of the glenoid face knotless-type anchor placement for arthroscopic Bankart repair has not been reported.

PURPOSE

To evaluate the clinical and radiologic outcomes after arthroscopic Bankart repair using knotless bioabsorbable anchors depending on the anchor location.

STUDY DESIGN

Case series, Level of evidence, 4.

METHODS

A total of 124 patients (113 men and 11 women; age, 25.6 ± 7.5 years; follow-up time, 46.5 ± 18.2 months [range, 6.2-75.5 months]) who underwent arthroscopic Bankart repair with the bioabsorbable knotless anchor between 2017 and 2021 were included in this study. Among them, 118 patients were observed for >2 years (mean, 48.2 ± 16.8 months [range, 24-75.5 months]) and were analyzed for final clinical and radiologic outcomes. Using postoperative 6-month magnetic resonance imaging, remnant glenoid (%) and labral height were measured. Shoulder range of motion (ROM), radiographic osteoarthritic change, dislocation, apprehension test, and return to sports were recorded. Three groups were established based on the remnant glenoid, which represented the percentage of the exposed glenoid anteroposterior diameter to the original diameter using the best-fit circle method-group A: lower quartile; group B: interquartile; and group C: upper quartile-and variables were analyzed.

RESULTS

Overall, the remnant glenoid was 57% ± 6.4% (range, 41.5%-75%) after the surgery. Osteoarthritic change, dislocations, and positive apprehension tests were observed in 5 (4.2%), 4 (3.4%), and 12 (10.2%) patients, respectively. A total of 34 (28.8%) and 64 (54.2%) patients could return to sports without and with restrictions, respectively. Comparing groups A, B, and C, postoperative labral height (7 ± 1, 7 ± 2, and 7 ± 1 mm; P = .623), final osteoarthritic change (1, 4, and 0; P = .440), positive apprehension tests (5, 5, and 2; P = .387), and return to sports (complete/restricted/unable, 6/18/5, 19/29/11, 9/17/4; P = .769) were not different. All ROM were similar across the groups (all P > .054), except for external rotation (ER) at postoperative 6 months (41.3°± 12.8°; 50.2°± 18.5°; and 49.8°± 15.2°; P = .050). However, ER after 1 year was similar across the groups (all P > .544). In further analysis, patients with positive apprehension tests had lower labral height compared with others (5 [4-6] mm and 7 [6-8] mm; P < .001).

CONCLUSION

In arthroscopic Bankart repair, the placement of knotless bioabsorbable anchors on the glenoid face, combined with the remplissage procedure or rotator interval closure, resulted in a low recurrence rate and moderate return to sports. However, most patients had some restrictions in returning to sports. Moreover, this technique was not associated with postoperative arthritis and shoulder stiffness, including ER deficit, which was not affected by the position of the anchor on the glenoid face for a minimum 2-year follow-up.

Anterior glenoid rim erosion in the early stage after arthroscopic Bankart repair affects postoperative recurrence

Background

Recent studies reported that anterior glenoid rim erosion can occur in the early period after arthroscopic Bankart repair (ABR) for traumatic anterior shoulder instability. However, it is unknown whether such erosion is a risk factor for postoperative recurrence. This study evaluated risk factors for postoperative recurrence after ABR, specifically aiming to elucidate whether reduction of postoperative glenoid width due to anterior glenoid rim erosion is one of such factors.

Methods

A total of 220 shoulders that underwent ABR alone between 2013 and 2020 were retrospectively investigated. Patient age at surgery, whether the patient was a collision/contact athlete, anchor placement, preoperative glenoid bone defect (%), localization of the Hill-Sachs lesion, and change of glenoid width (%) in the 6 months after surgery were investigated for their statistical relation to recurrence by univariate and multiple logistic regression analysis.

Results

Postoperative recurrence occurred in 32 of 220 shoulders (14.5%). In univariate analysis, being a collision/contact athlete was the only variable with a significant effect on recurrence (odds ratio [OR], 2.555; 95% confidence interval [CI], 1.123-5.814; P = .03). Change of glenoid width reduction was larger in those with recurrence than without recurrence, but the difference was not statistically significant (-7.0 ± 6.6% vs. -5.0 ± 9.3%; P = .14). However, in multivariate logistic analysis, preoperative glenoid bone defect (%) (adjusted unit OR, 1.076; 95% CI, 1.018-1.137; P = .010) and postoperative change of glenoid width (%) (adjusted unit OR, 0.946; 95% CI, 0.900-0.994; P = .028) had a significant influence on postoperative recurrence.

Conclusion

Glenoid width reduction due to anterior glenoid rim erosion after ABR is a risk factor for recurrence.

Inconsistencies in Controlling for Risk Factors for Recurrent Shoulder Instability After Primary Arthroscopic Bankart Repair: A Systematic Review

BACKGROUND

Failure rates after arthroscopic shoulder stabilization are highly variable in the current orthopaedic literature. Predictive factors for risk of failure have been studied to improve patient selection, refine surgical techniques, and define the role of bony procedures. However, significant heterogeneity in the analysis and controlling of risk factors makes evidence-based management decisions challenging.

PURPOSE

The goals of this systematic review were (1) to critically assess the consistency of reported risk factors for recurrent instability after arthroscopic Bankart repair, (2) to identify the existing studies with the most comprehensive inclusion of confounding factors in their analyses, and (3) to give recommendations for which factors should be reported consistently in future clinical studies.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of the literature was performed in accordance with the PRISMA guidelines. An initial search yielded 1754 titles, from which 56 full-text articles were screened for inclusion. A total of 29 full-text articles met the following inclusion criteria: (1) clinical studies regarding recurrent anterior shoulder instability; (2) surgical procedures performed including arthroscopic anterior labral repair; (3) reported clinical outcome data including failure rate; and (4) assessment of risk factors for surgical failure. Further subanalyses were performed for 15 studies that included a multivariate analysis, 17 studies that included glenoid bone loss, and 8 studies that analyzed the Instability Severity Index Score.

RESULTS

After full-text review, 12 of the most commonly studied risk factors were identified and included in this review. The risk factors that were most consistently significant in multivariate analyses were off-track lesions (100%), glenoid bone loss (78%), Instability Severity Index Score (75%), level of sports participation (67%), number of anchors (67%), and younger age (63%). In studies of bone loss, statistical significance was more likely to be found using advanced imaging, with critical bone loss thresholds of 10% to 15%. Several studies found predictive thresholds of 2 to 4 for Instability Severity Index Score by receiver operating characteristic or multivariate analysis.

CONCLUSION

Studies reporting risk factors for failure of arthroscopic Bankart repair often fail to control for known confounding variables. The factors with the most common statistical significance among 15 multivariate analyses are off-track lesions, glenoid bone loss, Instability Severity Index Score, level of sports participation, number of anchors, and younger age. Studies found significance more commonly with advanced imaging measurements or arthroscopic assessment of glenoid bone loss and with lower thresholds for the Instability Severity Index Score (2-4). Future studies should attempt to control for all relevant factors, use advanced imaging for glenoid bone loss measurements, and consider a lower predictive threshold for the Instability Severity Index Score.

On-the-Edge Anchor Placement May Be Protective Against Glenoid Rim Erosion After Arthroscopic Bankart Repair Compared to On-the-Face Anchor Placement

PURPOSE

This retrospective study aimed to compare the effects of 2 different anchoring placements on glenoid rim erosion after arthroscopic Bankart repair (ABR).

METHODS

Shoulders that underwent ABR from January 2013 to July 2020 were divided into 2 groups according to anchor placement (on-the-face, group F; on-the-edge, group E). We retrospectively calculated the percent change of glenoid width (Δ) on the first postoperative computed tomography scan (CT; performed within 6 months) and second postoperative CT (performed at 6 to 12 months) relative to the width on the preoperative CT and compared percent changes between the 2 groups. Also, we investigated the influence of preoperative glenoid structures (normal, erosion, bony Bankart) and the postoperative recurrence rate.

RESULTS

We examined 225 shoulders in 214 patients (group F, n = 151; group E, n = 74). At first CT, anchoring placement was significantly associated with postoperative decrease of glenoid width (group F, -7.6% ± 7.9%; group E, -0.1% ± 9.7%; P < .0001). The difference between groups F and E was significant in shoulders with a preoperative glenoid defect (bony Bankart, -6.6% ± 8.8% vs 2.5% ± 11.2%, respectively; P < .0001; erosion, -6.6% ± 6.2% vs -2.6% ± 5.3%, respectively; P = .03). In 112 shoulders, CT was performed twice; Δ was -6.9% ± 7.3% in group F (n = 64) and -1.7% ± 10.1% in group E (n = 48; P = .005) at the first CT and -3.2% ± 10.0% and 1.0% ± 10.6% (P = .10), respectively, at the second CT, indicating recovery of glenoid width in both groups. The postoperative recurrence rate in patients with at least 2 years' follow-up was 14.7% in group F and 14.6% in group E.

CONCLUSIONS

In the early stage after ABR, on-the-edge glenoid anchor placement was associated with less glenoid rim erosion than on-the-face anchor placement.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

Treatment of lower part of glenoid fractures through a novel axillary approach: A case report

BACKGROUND

Based on the location and size of the fracture block, open reduction and internal fixation can be employed or assisted for shoulder arthroscopy in the treatment of glenoid fractures. However, the treatment of lower part of glenoid fractures through a novel axillary approach has not been reported so far.

CASE SUMMARY

A 22-year-old right-handed man was transferred to our outpatient clinic because of right shoulder injury during a traffic accident. X-ray examination after admission suggested the fracture of the lower part of the right glenoid and an ipiselial proximal humeral fracture. Three-dimensional (3D) computed tomography (CT) further suggested that the size of the fracture block of the lower part of the right glenoid was 3.4 mm × 16.2 mm. The patient was diagnosed as the fracture of the lower part of the glenoid, also known as bony Bankart lesion without shoulder dislocation. After general anesthesia, the patient was surgically treated with the open reduction internal fixation through a novel axillary approach. 3D CT and shoulder joint function were reexamined at 12 mo of follow-up, showing acceptable recovery.

CONCLUSION

This case report describes a novel axillary approach adopted in an open reduction with cannulated screw and wire anchor internal fixation. After a follow-up for more than 12 mo, 3D CT and shoulder joint function examinations display a good recovery.

Glenoid bone resorption after Bankart repair: finite element analysis of postoperative stress distribution of the glenoid

BACKGROUND

There are various modifications of the Bankart repair, and postoperative changes to the glenoid morphology after the repair are reported. Among the various procedures performed, a decrease in the lateral glenoid diameter might be related to the surgery that involves removal of the articular cartilage and repair of the labrum-anterior inferior glenohumeral ligament complex on the glenoid surface. This is in contrast to cases without significant bony Bankart lesions that are not on the edge of the glenoid. Thus, this study aimed to compare glenoid rim stress after Bankart repair using 2 methods of finite element analysis: a method of removing the anteroinferior cartilage and repairing the glenohumeral ligament complex on the glenoid and a method of preserving the cartilage and repairing the glenohumeral ligament complex on the glenoid edge.

METHODS

Five preoperative computed tomography scans of patients with traumatic anterior instability who underwent arthroscopic Bankart repair were used. Two models simulating different surgical procedures were created as follows: in model G, a 5-mm-thick cartilage on the glenoid rim was removed between 2 and 7 o'clock, and the glenohumeral ligament complex was repaired on the medial edge of the glenoid bone where the cartilage was removed. In model E, the cartilage on the glenoid rim was not removed, and the glenohumeral ligament complex was repaired on the glenoid edge. The load stresses on the anteroinferior area of the glenoid after Bankart repair with models G and E were measured using finite element analysis.

RESULTS

The stress on the glenoid at 3-4 o'clock was 3.16 MPa in model G and 6.42 MPa in model E (P = .043). The stress at 4-5 o'clock was 1.68 MPa in model G and 4.53 MPa in model E (P = .043). The stress at 5-6 o'clock was 2.26 MPa in model G and 3.93 MPa in model E (P = .043).

CONCLUSION

Significantly lower load stresses were observed at the anteroinferior rim of the glenoid in model G than in model E.

Does anchor insertion angle or placement of the suture anchor affect glenoid rim fracture occurrence after arthroscopic Bankart repair?

BACKGROUND

The purposes were to compare the characteristics of 2 groups of patients who underwent revision Bankart repair with and without glenoid rim fractures and to examine risk factors for glenoid rim fractures.

METHODS

We retrospectively analyzed 39 patients who needed revision surgery after arthroscopic Bankart repair and identified 19 patients with and 20 patients without glenoid rim fractures. The insertion angle of the suture anchor, anchor position on the glenoid, and demographic data were compared between the groups.

RESULTS

The mean anchor insertion angles in the glenoid fracture group (group F) at the 2-, 3-, 4-, and 5-o'clock positions were 64°, 58°, 55°, and 55°, respectively; those in the no-fracture group (group R) were 60°, 63°, 60°, and 55°, respectively (P = .630, P = .207, P = .166, and P = .976, respectively). At the 5-o'clock position, anchors were fixed to the glenoid face in 13 cases in group F and in 3 cases in group R (P = .040). Although age (P = .529) and sex (P = 1.0) did not differ between the groups, elite and professional athletes had a significantly higher incidence of glenoid rim fractures (P = .009).

CONCLUSION

The anchor insertion angle did not affect glenoid rim fracture occurrence after arthroscopic Bankart repair. However, the placement of the suture anchor at the 5-o'clock position on the glenoid face could increase the risk of glenoid rim fracture after trauma. Athletes were more likely to have glenoid rim fractures owing to major trauma after arthroscopic Bankart repair.

Progression of Erosive Changes of Glenoid Rim After Arthroscopic Bankart Repair

PURPOSE

To evaluate changes of the glenoid after arthroscopic Bankart repair (ABR) in patients with different preoperative glenoid structures.

METHODS

Patients who underwent ABR for traumatic anterior shoulder instability were retrospectively investigated. They were divided into 3 groups on the basis of preoperative glenoid structure by computed tomography (CT): normal glenoid (group N), glenoid erosion (group E), or glenoid defect associated with a bony Bankart lesion (group B). Shoulders in group B were also stratified according to the postoperative status of the bone fragment (union, nonunion, or resorbed). Postoperative changes of glenoid width (Δ) (increase: Δ ≥5%, stable: Δ >-5% to <5%, decrease: Δ ≤-5%) and the extent of glenoid bone loss were investigated by 3-dimensional CT.

RESULTS

A total of 186 shoulders were divided into 3 groups: group N (n = 61), group E (n = 46), and group B (n = 79). At initial postoperative CT, the glenoid width was decreased in 41 shoulders, stable in 20 shoulders, and increased in no shoulders from group N. The respective numbers were 27, 18, and 1 in group E, and 50, 22, and 7 in group B. The glenoid width was reduced in all groups (mean percent change: -8.8%, -5.9%, and -6.1%, respectively). In group B, glenoid width decreased in most of the shoulders without bone union. The glenoid bone loss on the preoperative and postoperative final CT was, respectively, 0% and 8.6% in group N (P < .0001), 9.9% and 12.4% in group E (P = .03), and 10.4% and 7.2% in group B (P = .01). Final glenoid bone loss >13.5% was recognized in 18.2% of group N, 35.7% of group E, and 21.8% of group B.

CONCLUSIONS

Glenoid width often decreased after ABR because of anterior glenoid rim erosion, and this change was frequent in patients with preoperative normal glenoid, glenoid erosion, or without postoperative union of a bony Bankart lesion.

LEVEL OF EVIDENCE

Level 3, Case-control study.

Editorial Commentary: Is Arthroscopic Bankart Repair Using Suture Anchors on the Glenoid Appropriate Treatment for Traumatic Anterior Shoulder Instability?

Fracture of the anterior glenoid rim along the sites of suture anchor insertion is not rare after arthroscopic Bankart repair for traumatic anterior shoulder instability. In addition to the influence of the number, type, and size of the suture anchors, placing multiple anchors in a linear arrangement might impose excessive stress on the surrounding bone, leading to critical loss of osseous integrity and glenoid fracture. Although highly active young male collision or contact athletes are most at risk, such fractures sometimes occur after relatively minor trauma at a long interval after surgery, suggesting persistent impairment of bone quality. In patients with postoperative recurrence of instability, detailed examination using computed tomography is recommended.

Variability of Reporting Recurrence After Arthroscopic Bankart Repair: A Call for a Standardized Study Design

Background

High recurrence rates have been reported after anterior shoulder dislocations, regardless of the treatment utilized. However, the definition of recurrent instability has been inconsistent, making a comparison between studies difficult.

Purpose

To report on the nature with which the rate of recurrent instability is reported after arthroscopic Bankart repair, across all levels of evidence, and to analyze factors that may affect the reported rate of recurrence.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review of the literature was performed by searching PubMed, the Cochrane Central Register of Controlled Trials, Embase, and ClinicalTrials.gov for studies published within the dates of January 2008 and September 2018. Studies in English that reported on the recurrence of instability after arthroscopic Bankart repair for anterior shoulder instability were considered for inclusion in this review. A meta-regression was performed to test for a linear association between the reported recurrence rate and several continuous covariates, including mean age at surgery, mean length of follow-up, attrition rate (loss to follow-up percentage), and percentage of male patients.

Results

A trim-and-fill meta-analysis yielded an estimated overall recurrence rate of 17.4% (95% CI, 14.3%-20.9%). There was a significant difference in the recurrence rate depending on the level of evidence (Q(3) = 10.98; P = .012). Significant associations were found with the recurrence rate through the meta-regression, including a negative association with mean age (P = .009), a positive association with mean follow-up time (P = .002), and a positive association with attrition rate (P = .035).

Conclusion

A call for standardization is necessary for reporting outcomes of anterior instability after arthroscopic Bankart repair, especially with regard to the reporting of recurrence/failure rates, with careful consideration of the effects that may occur from patient demographics and study design. With no current recommendations for deeming failure, we suggest that all forms of instability be accounted for when determining a failed treatment procedure, with future studies placing an emphasis on greater control of the study design.