An Anatomic and Biomechanical Comparison of Bankart Repair Configurations

Arthroscopic Management of Anterior Shoulder Instability: A Study of Functional Outcome and Analysis

Background The remarkable range of motion of the shoulder comes at the cost of increased instability, especially anterior instability. Arthroscopic Bankart repair with or without remplissage, which is a minimally invasive surgery, is the preferred treatment for recurrent anterior instability. This study investigated the effectiveness of Bankart repair, with or without remplissage, in restoring function, preventing redislocation, and improving patient satisfaction. Methods A prospective observational study examined 40 patients (19-50 years old) with recurrent anterior instability and MRI-confirmed Bankart or Bankart with Hill-Sachs lesions. Patients underwent arthroscopic Bankart repair with or without remplissage based on the inclusion criteria of this study. Preoperative assessments included demographics, history, physical examination, American Shoulder and Elbow Surgeons (ASES) score, Quick Disabilities of the Arm, Shoulder, and Hand (DASH) score, ROWE score, and plain MRI of the shoulder joint. Post-operative radiographs and rehabilitation were advised. Functional recovery was evaluated at three months and six months after surgery. Results All patients underwent Bankart repair. Among them, 22 with engaging Hill-Sachs lesions received an additional remplissage procedure. Both groups showed significant improvements in their functional scores (p<0.05) and returned to their prior activities. However, the additional remplissage group had a slightly reduced mean external rotation (86.59°) compared with the Bankart repair-only group (90°). Notably, the recurrence rate was very low, with only one patient (2.5%) experiencing instability. Conclusion  Our study emphasizes the importance of proper capsulolabral tissue elevation to achieve a sufficient labral bump during Bankart repair. This technique allowed us to efficiently use only two suture anchors in 35 cases (87.5%). Additionally, remplissage was performed on all identified engaging Hill-Sachs lesions. We found that proper anchor placement and suturing techniques were crucial for successful Bankart repair. The emphasis on the potential cost benefits of a two-anchor approach is a valuable contribution to the field.

The New Double-row Bankart Repair Recovered Shoulder Stability without Excessive Motion Limitation: A Case-Control Study with Single-row Bankart Repair

OBJECTIVES

Bankart lesion is one of the most common lesions of the glenohumeral joint. Several double-row suture methods were reported for Bankart repair, which could provide more stability, yet more motion limitation and complications. Therefore, we introduced a new double-row Bankart repair technique, key point double-row suture which used one anchor in the medial line. The purpose of this article is to investigate the clinical outcomes of this new method and to compare it with single-row suture.

METHODS

Seventy-eight patients receiving key point double-row suture or single-row suture from October 2010 to June 2014 were collected retrospectively. The basic information including gender, age, dominant arm, and number of episodes of instability was collected. Before surgery, the glenoid bone loss was measured from the CT scan. The visual analogue scale, American shoulder and elbow surgeons, the University of California at Los Angeles shoulder scale, and subjective shoulder value were valued before surgery and at the last follow-up.

RESULTS

Forty-four patients (24 patients receiving single-row suture and 20 patients receiving key point double-row suture) were followed up successfully. The follow-up period was 9.2 ± 1.1 years (range, 7.8-11.4 years). At the last follow-up, no significant differences were detected for any of the clinical scores. The recurrence rate was 12.5% for the single-row group and 10% for the double-row group, respectively (p = 0.795) 14 patients (31.8%) in the single-row group and nine patients (26.5%) in the double-row group were tested for active range of motion. A statistically significant difference was found only for the internal rotation at 90° abduction (48.9° for single-row and 76.7° for key point double-row, p = 0.033).

CONCLUSION

The key point double-row sutures for Bankart lesions could achieve similar long-term outcomes compared with single-row suture, and one medial anchor did not result in a limited range of motion. The low recurrence rate and previous biomechanical results also indicate the key point double-row suture is a reliable method.

No difference in biomechanical properties of simple, horizontal mattress, and double row repair in Bankart repair: a systematic review and meta-analysis of biomechanical studies

BACKGROUND

Arthroscopic Bankart repair is the most common procedure in patients with anterior shoulder instability. Various repair techniques using suture anchors have been used to improve the strength of fixation and surgical outcomes in arthroscopic Bankart surgery. However, evidence regarding which method is superior is lacking. This systematic review and meta-analysis study was designed to compare the biomechanical results of simple versus horizontal mattress versus double-row mattress for Bankart repair.

METHODS

A systematic search of the MEDLINE, Embase, and Cochrane Library databases was performed to identify comparative biomechanical studies comparing the simple, horizontal mattress, and double-row techniques commonly used in Bankart repair for anterior shoulder instability. Biomechanical results included the ultimate load to failure, stiffness, cyclic displacement, and mode of failure after the ultimate load. The methodological quality was assessed based on the Quality Appraisal for Cadaveric Studies (QUACS) scale for biomechanical studies.

RESULTS

Six biomechanical studies comprising 125 human cadavers were included in this systematic review. In biomechanical studies comparing simple and horizontal mattress repair and biomechanical studies comparing simple and double-row repair, there were no significant differences in the ultimate load to failure, stiffness, or cyclic displacement between the repair methods. The median QUACS scale was 11.5 with a range from 10 to 12, indicating a low risk of bias.

CONCLUSION

There was no biomechanically significant difference between the simple, horizontal mattress, and double-row methods in Bankart repair. Clinical evidence such as prospective randomized controlled trials should be conducted to evaluate clinical outcomes according to the various repair methods.

LEVEL OF EVIDENCE

Systematic review, Therapeutic level IV.

Single- and Double-Loaded All-Suture Anchor Repairs of Anteroinferior Labral Tears Are Biomechanically Similar in a Cadaveric Shoulder Model

Purpose

To compare the biomechanical strength of single- versus double-loaded all-suture constructs in an anteroinferior glenoid labral repair.

Methods

Anteroinferior labral lesions were created on 6 matched pairs of cadaveric shoulder specimens. Each shoulder in a matched pair was randomized to either receive capsulolabral repair with 3 single-loaded all-suture anchors or 3 double-loaded all-suture anchors. Immediately following capsulolabral repair, the specimens underwent mechanical testing, which included cyclic testing (5 N to 50 N for 500 cycles) and load-to-failure testing (rate of 15 mm/min). The gap formation between the repaired labrum and glenoid (measured at 1, 25, 100, and 500 cycles), the load at 2-mm gap formation, the maximum load at failure and the method of failure were recorded. Data were analyzed with paired Student t tests and Bonferroni correction factor.

Results

The single and double all-suture constructs did not differ significantly in gap formation at any number of cycles, load to 2-mm gap formation (P = .75), or maximum load to failure (P = .46) between the 2 groups.

Conclusions

In this study, single-loaded and double-loaded all-suture anchor constructs demonstrated comparable biomechanical performance and did not significantly differ in gap formation, load to 2-mm gap formation, or maximum load to failure when used in the capsulolabral repair of anteroinferior glenoid labral tears in human cadaveric specimens.

Clinical Relevance

Although studies have evaluated the biomechanical properties of various arthroscopic labral stabilization techniques, the biomechanical properties of all-suture anchors with regard to labral stabilization are not well understood.

Ability to Retension Knotless Suture Anchors: A Biomechanical Analysis of Simulated Bankart Lesions

Background:

Knotless suture anchors are gaining popularity in arthroscopic glenohumeral labral repairs. The ability to retension knotless designs after initial anchor placement has been reported; however, no studies have quantified this claim or investigated the biomechanical consequence of retensioning.

Purpose/Hypothesis:

To determine whether knotless and knotted suture anchors have biomechanical or anatomic differences with regard to labral repairs and to determine whether retensioning of knotless suture anchors affects capsular tension, labral height, and capsular shift. We hypothesized that retensioning of knotless anchors would result in improved capsular tension compared with conventional knotted suture anchors.

Study Design:

Controlled laboratory study.

Methods:

A total of 18 fresh-frozen cadaveric shoulders with a mean age of 56 years were dissected to the capsule and disarticulated at the humeral capsular insertion. The scapula was potted and placed in a custom shoulder simulator to tension the capsule via braided sutures localized to the anteroinferior glenohumeral ligament. Specimens were randomized into 3 groups: (1) Knotted (KT), (2) Knotless with end retensioning (KL_end), and (3) Knotless with stepwise retensioning (KL_stepwise). All repairs were completed using all-suture anchors placed at the 5-, 4-, and 3-o’clock positions. KL_stepwise was used to simulate an intraoperative technique. Resultant mean capsular tension under 5 mm of displacement (subfailure loading) was measured for each anchor placement and retensioning step. Labral height and capsular shift were measured using a MicroScribe digitizer.

Results:

The intact, defect, 1-anchor, 2-anchor, and 3-anchor tensions were not significantly different between the KT and KL_end groups. For the latter, retensioning of all knotless anchors increased capsular tension by 2.1 N compared with its 3-anchor state, although this was not statistically significant (P = .081). The KL_stepwise group explored an alternative method to retension the capsule using knotless anchors, with similar final capsular tensions compared with the other groups. All repairs had similar improvements in capsulolabral height and superior capsular shift.

Conclusion:

Knotted and knotless suture anchors provided similar overall restorations in anteroinferior glenohumeral ligament tension. However, knotless devices were capable of small but statistically insignificant improvements in capsular tension with retensioning.

Clinical Relevance:

Retensioning of knotless anchors allows the surgeon to tighten regions of the glenohumeral capsule that remain lax after repair.

Biomechanical Studies for Glenoid Based Labral Repairs With Suture Anchors Do Not Use Consistent Testing Methods: A Critical Systematic Review

PURPOSE

The purpose of this systematic review was to investigate variability in biomechanical testing protocols for laboratory-based studies using suture anchors for glenohumeral shoulder instability and SLAP lesion repair.

METHODS

A systematic review of Medline, Embase, Scopus, and Google Scholar using Covidence software was performed for all biomechanical studies investigating labral-based suture anchor repair for shoulder instability and SLAP lesions. Clinical studies, technical notes or surgical technique descriptions, or studies treating glenoid bone loss or capsulorrhaphy were excluded. Risk of bias (ROB) was assessed with the ROBINS-I tool. Study quality was assessed with the Quality Appraisal for Cadaveric Studies. Heterogeneity was assessed with the I² statistic.

RESULTS

A total of 41 studies were included. ROB was serious and critical in 27 studies, moderate in 13, and low in 1; 6 studies had high quality, 21 good quality, 10 moderate quality, 2 low quality, and 2 very low quality. Thirty-one studies used and 22 studies included cyclic loading. Angle of anchor insertion was reported by 33 studies. The force vector for displacement varied. The most common directions were perpendicular to the glenoid (n = 9), and anteroinferior or anterior (n = 8). The most common outcome measures were load to failure (n = 35), failure mode (n = 23), and stiffness (n = 21). Other outcome measures included load at displacement, displacement at failure, tensile load at displacement, translation, energy absorbed, cycles to failure, contact pressure, and elongation.

CONCLUSION

This systematic review demonstrated a clear lack of consistency in those cadaver studies that investigated biomechanical properties after surgical repair with suture anchors for shoulder instability and SLAP lesions. Testing methods between studies varied substantially with no universally applied standard for preloading, load to failure and cyclic loading protocols, insertion angles of suture anchors, or direction of loading. To allow comparability between studies standardization of testing protocols is strongly recommended.

Simple versus horizontal mattress suture configuration in bankart repair

The purpose of this article was to compare the anatomy and biomechanics of different suture repair configurations for arthroscopic Bankart lesion repair. The horizontal mattress technique improves the restoration of labral height and decreases capsular strain in comparison to simple suture repairs. Further research examining the clinical outcomes of horizontal mattress suture technique is required for comparison with simple suture arthroscopic Bankart repairs.

Biomechanical Evaluation of Knotless and Knotted All-Suture Anchor Repair Constructs in 4 Bankart Repair Configurations

PURPOSE

To evaluate the biomechanical performance of Bankart repair using 1.8-mm knotless all-suture anchors in comparison to 1.8-mm knotted all-suture anchors with both simple and horizontal mattress stitch configurations.

METHODS

Thirty fresh-frozen human cadaveric shoulders were dissected to the capsule, leaving the glenoid and humeral capsular insertions intact. A standardized anteroinferior labral tear was created and repaired using 3 anchors. A 2 × 2 factorial design was implemented, with 6 matched pairs randomized between knotless and knotted anchor repairs and 6 matched pairs randomized into simple and horizontal mattress stitch configurations. In addition, 6 unpaired shoulders were used to evaluate the native capsulolabral state. First failure load, ultimate load, and stiffness were assessed. Linear mixed-effects modeling was used to compare endpoints. Digital image correlation was used to evaluate capsular strain throughout testing. Failure modes were reported qualitatively.

RESULTS

The knotless all-suture anchor repair showed similar biomechanical strength to the knotted all-suture anchors for first failure load (coefficient, 142 N; 95% confidence interval [CI], -30 to 314 N; P = .12), ultimate load (coefficient, 11.1 N; 95% CI, -104.9 to 127.2 N; P = .847), and stiffness (coefficient, 3.4 N/mm²; 95% CI, -14.1 to 20.9 N/mm²; P = .697) when stitch configuration was held constant. No statistically significant differences were found on comparison of simple and mattress stitch configurations for first failure load (coefficient, -31 N; 95% CI, -205 to 143 N; P = .720), ultimate load (coefficient, 112 N; 95% CI, -321 to 97 N; P = .291), and stiffness (coefficient, -9.6 N/mm²; 95% CI, -27.3 to 8.1 N/mm²; P = .284) when anchor type was held constant. Specimens with knotless anchors and simple stitch techniques resulted in lower stiffness compared with the native state (P = .030). The knotless-mattress configuration resulted in significantly lower strain than the knotted-mattress (P = .037) and knotless-simple (P = .019) configurations and was the only configuration that did not result in a significant increase in strain compared with the intact specimens (P = .216). Fewer instances of suture slippage (loss of loop security) were observed with knotless anchors versus knotted anchors (11% vs 30%), and less soft-tissue failure was observed with the mattress stitch configuration versus the simple stitch configuration (36% vs 47%).

CONCLUSIONS

Knotless and knotted all-suture anchor repairs with simple and mattress stitch configurations showed similar values of ultimate load, first failure load, and stiffness. However, the horizontal mattress stitch configuration proved to decrease capsular strain more similarly to the native state compared with the simple stitch configuration. Ultimate load and first failure load for all repairs were similar to those of the native state.

CLINICAL RELEVANCE

Knotless all-suture anchors have a smaller diameter than solid anchors, can be inserted through curved guides, and preserve glenoid bone stock. This study presents knotless, tensionable all-suture anchor repair for labral tears that displays high biomechanical fixation strength, similar to the native capsulolabral state.

Anchor placement to glenoid rim during Bankart repair recreates contact area of anterior capsulolabral complex on glenoid better than onto articular surface

PURPOSE

This study aimed to compare the contact areas of Bankart repair with suture anchors placed on the articular surface of the glenoid versus at the rim of the glenoid because it is unclear which technique most effectively restores the footprint after Bankart repair.

METHODS

Ten fresh frozen cadaveric shoulders (mean age 70.7 years) were dissected. The attachment site of the capsulolabral complex from the 1 o' clock position to the 6 o'clock position was marked with ink, and the contact area of the anterior-inferior capsulolabral complex on the glenoid neck was measured using imageJ. Bankart lesions were created, and two types of Bankart repair were performed on each specimen. The suture anchors were inserted at the glenoid rim (Rim group) and onto the glenoid articular surface 2 mm from the rim (Surface group). Using pressure-sensitive films, we examined the interface contact area.

RESULTS

The Rim group recreated 64.9% of the native surface area, while the Surface group recreated 47.3% of the area. The Rim group recreated significantly greater contact area compared to the Surface group (P = 0.0008).

CONCLUSION

The anchor placement to the glenoid rim recreates the footprint of the capsulolabral complex on the anterior inferior glenoid better than the anchor placement onto the articular surface.

The 6-O'clock Anchor Increases Labral Repair Strength in a Biomechanical Shoulder Instability Model

PURPOSE

To characterize the additive effect of a 6-o'clock anchor in the stabilization of a Bankart lesion.

METHODS

Twelve cadaveric shoulders were tested on a 6-df robotic musculoskeletal simulator to measure the peak resistance force due to anterior displacement of 1 cm. The rotator cuff muscles were loaded dynamically. The test conditions consisted of the intact shoulder, Bankart lesion, Bankart repair (3-, 4-, and 5-o'clock anchors), and Bankart repair with the addition of a 6-o'clock anchor. A 13% anterior bone defect was then created, and all conditions were repeated. Repeated-measures analysis of variance was performed.

RESULTS

In the group with no bone loss, the addition of a 6-o'clock anchor yielded the highest peak resistance force (52.8 N; standard deviation [SD], 4.5 N), and its peak force was significantly greater than that of the standard Bankart repair by 15.8% (7.2 N, P = .003). With subcritical glenoid bone loss, the repair with the addition of a 6-o'clock anchor (peak force, 52.6 N; SD, 6.1 N; P = .006) had a significantly higher peak resistance force than the group with bone loss with a Bankart lesion (35.2 N; SD, 5.8 N). Although the 6-o'clock anchor did increase the strength of the standard repair by 6.7%, this was not statistically significant (P = .9) in the bone loss model.

CONCLUSIONS

The addition of a 6-o'clock suture anchor to a 3-anchor Bankart repair increases the peak resistance force to displacement in a biomechanical model, although this effect is lost with subcritical bone loss.

CLINICAL RELEVANCE

This study provides surgeons with essential biomechanical data to aid in the selection of the repair configuration.

[Research progress of surgical treatment for anterior shoulder dislocation and combined injuries]

Objective

To summarize the research progress of surgical treatment for anterior shoulder dislocation and combined injuries.

Methods

The related literature was reviewed, and the surgical treatment options for the anterior shoulder dislocation and its combined injuries were summarized.

Results

Anterior shoulder dislocation can combine with anteroinferior capsular ligament complex injury (Bankart injury), bony Bankart defect, and Hill-Sachs lesion. For Bankart and bony Bankart injuries, arthroscopic repair or coracoid osteotomy combined with bony graft reconstruction can be performed. For Hill-Sachs lesion, conservative treatment, soft tissue repair, or bony reconstruction should be selected based on the extent of the bone defect. For bipolar injury, the Bankart repair, Remplissage, or arthroplasty should be selected based on the extent of the glenoid defect.

Conclusion

With the development of arthroscopy and the improvement of the surgical concept, there is a complete set of surgical options for various injuries of the anterior shoulder dislocation. When choosing a surgical procedure, the patient's specific injury and age, exercise level, and other relating factors should be comprehensively assessed in order to achieve the best results.