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.


Introduction
T he capsulolabral complex, composed of the glenohumeral ligament and capsule, is an important soft structure, providing stabilization when the humerus shifts anteriorly.On the contrary, when the shoulder dislocates anteriorly where the cuff muscles are also weak, the capsulolabral complex is easily torn off, that is, a Bankart lesion has occurred.Since this lesion was described by Bankart 1 in 1938, it has been one of the common pathologies in shoulder lesions, which causes 7.9%-50.0% of the traumatic glenohumeral instability. 2So, trying to fix it is critical to restoring the stability of the shoulder joint.
The repair of a Bankart lesion is reattaching the capsulolabral complex to the rim of the glenoid, which is usually performed arthroscopically.Porcellini et al. 3 first published the results of the arthroscopic Bankart repair in 25 patients with at least a 2-year follow-up, and most patients restored function and stability.The Bankart repair could be divided into single-row and double-row according to the configuration of suture anchors.Lafosse et al. 4 invented the double-row repair method, which was called Cassiopeia double-row technique in their article.He also reported the short-term results in 12 patients, and there were no complications or recurrence of instability.After that, many biomechanical studies confirmed the advantages of double-row repair.Ahmad et al. 5 found that double-row repair got a larger footprint area providing the basis of healing.Kim et al. 6 reported stress could achieve broader area and even distribution in double-row repair.Spiegl et al. 2 concluded that the shoulder with a double-row repair could sustain a greater load.Although McDonald et al. 7 reported the double-row repair resulted in more external rotation loss, the kinematics test still supported double-row repair.
In short, the clinical results of single-row Bankart repair were still unsatisfied, while the double-row suture was short of clinical data.To combine the advantages of both methods, we created a brand-new suture method based on traditional double-row repair-key point double-row repair, which just uses one anchor in the medial line.Our study aims to: (i) introduce the new suturing method; (ii) evaluate the efficacy of key point double-row repair; and (iii) compare it with single-row repair.Our hypothesis is key point double-row repair could achieve clinical results no inferior to single-row repair.

Study Design
This study received approval of the ethics committee before initiation (No.M2022685).The main steps included selecting patients, collecting data, and comparing differences.The patients' information was retrospectively obtained from recorded medical history and the personal and private information was concealed.

Patient Selection
From October 2010 to June 2014, 78 patients with Bankart lesions received procedures in our hospital, 44 using singlerow repair and 34 using key point double-row repair.The inclusion criteria were: (i) having a history of recurrent anterior shoulder instability (more than 1 instability episode); (ii) an arthroscopic exam confirmed there were Bankart lesions; and (iii) cooperating with the surgeries and rehabilitations.The exclusion criteria were: (i) having a history of epilepsy; (ii) posterior or multi-directional instability; (iii) glenoid bone loss ≥25%; and (iv) arthroscopy found large Hill-Sachs lesions (>25% of articular surface 8 ).All procedures were performed by one experienced surgeon.The basic information was collected and compared between the two groups.

Surgical Technique
The patients were placed in an oblique lateral decubitus position and anesthetized regularly.After checking the anterior shoulder instability test, Sulcus test, and laxity of every direction, the places of the acromion, coracoid, and acromioclavicular joint were marked.A standard posterior portal was used for a diagnostic arthroscopy, looking for synovium, Bankart lesions, glenohumeral joint, possible glenoid cartilage and bone loss, biceps tendon, subscapularis, posterior capsule, and possible Hill-Sachs lesions.The anterior superior portal and anterior inferior portal were established under arthroscopic observation.The arthroscopy was moved to the anterior superior portal for observation.Then using a periosteal stripper, the anteroinferior glenohumeral ligament and labrum complex were released across the glenoid rim and neck to 6 o'clock.Through the anterior inferior portal, three to four suture anchors were inserted at the edge of the glenoid, and sutures were threaded through the capsulolabral complex with a simple suture style by a lasso to knot.
The key point double-row technique is similar to the single-row.The difference was inserting an additional anchor in the 5'clock medial to glenoid surface 10 mm through the 5 o'clock portal.And sutured glenohumeral ligament and labrum complex with a mattress suture style (Figure 1).

Post-operative Protocol
Patients wore a shoulder sling with an abduction pillow for 6 weeks.One-week post-operation active-assisted range of motion was progressed in forward flexion and external rotation.Combined abduction and external rotation were avoided until 12 weeks.Patients were allowed to return to sports at 6 months.

Clinical Assignment
The visual analogue scale (VAS) for pain and instability, the rating scale of the American shoulder and elbow surgeons (ASES), the University of California at Los Angeles (UCLA) shoulder scale, and subjective shoulder value (SSV) were used to evaluate clinical outcomes.All scores were taken before surgery and at the last follow-up.The glenoid bone loss before surgery was measured by CT scan and the value was obtained from the following equation: glenoid bone loss = (maximum defect width/diameter of the best-fit circle) Â 100%.

Statistical Analysis
For dichotomous data, the chi-square test was used to compare.For other data, the group t-test was used for the comparison of normal distribution data, and the Mann-Whitney U test was used for non-normal distribution data.All analyses were made with the Statistical Package for Social Science version 26.A significant difference was defined as p < 0.05.

Baseline Information
Finally, 24 patients (54.5%) receiving single-row suture and 20 patients (58.8%) receiving key point double-row suture were followed up successfully.To eliminate the selective bias, the comparison between responders and non-responders was summarized in Table 1, which did not show any difference except the gender.There were 12 females in the single-row group and five females in the double-row group.The followup time for the single-row group was 9.2 AE 1.1 years (range, 7.8-11.2years), and for the double-row group was 9.3 AE 1.2 years (range, 7.9-11.4years).For the single-row  The preoperative clinical scores between the two groups did not show any difference.The demographics were shown in Table 2.

Clinical Outcomes
For the single-row group, the VAS for pain decreased from 4.8 in pre-operation to 2.7 in post-operation (p = 0.006) and VAS for instability also decreased from 7.7 to 1.9 (p < 0.001).A significant improvement in ASES was observed (from 61.8 to 83.2, p < 0.001).UCLA was enhanced from 27.6 to 33.8 (p < 0.001) and SSV increased from 57.4 to 86.3 (p = 0.001).The results of the double-row group were as excellent as the single-row.VAS for pain alleviated from 5.0 to 1.8 (p = 0.015).VAS for instability got a great relief (from 7.5 to 1.1, p < 0.001).The mean ASES score increased more than 20 (62.0 vs. 89.5, p = 0.001).UCLA rose from 29.5 to 33.5 ( p = 0.006).SSV enhanced from 59.2 to 89.5 (p = 0.001) (Table 3).A comparison between the two groups can be seen in Table 3.There was no significant difference for VAS (for pain, p = 0.387; for instability, p = 0.345), ASES (p = 0.302), UCLA (p = 0.751), or SSV (p = 0.924), although the mean values seemed better in the double-row group (Table 4).The recurrence rate of the single-row group was 12.5% (3/24), while it was 10% for the double-row group ( p= 0.795).

Range of Motion
Fourteen 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.The forward flexion, external rotation at the side, internal rotation at the side, and external rotation at 90 abduction did not have statistical differences.However, internal rotation at 90 abduction was significantly better in the double-row group (48.9 vs. 76.7,p = 0.033) (Table 5).

Discussion
T he main finding of this research was that the key point double-row Bankart repair could achieve excellent clinical outcomes and a very low recurrence rate, although it didn't express significant advantages compared with singlerow repair in our cases.The key point double-row repair still   provided a good idea to combine the superiority of singlerow and double-row suture.More stability and fewer anchor-associated complications may support this new suture method.

Key Point Double-row Repair is a Useful Technique for Bankart Lesion
One of the advantages of our research was that it is a longterm comparative study.Similar to our technique, Itoigawa et al. 9 also reported a new suture method called 4 o'clock double anchor footprint fixation (DAFF).The difference was they used mattress sutures while bridge sutures were used in our study.Their fixation method was inspired by an anatomic research, 10 which revealed the area of capsulolabral complex attachment on the glenoid neck wasn't even and there was a maximum adhesion region in the direction of 4 o'clock but this natural feature wasn't restored after repairing by a single-row suture. 11They reported a shortterm result of 42 patients and the UCLA and Rowe scores got significant improvements.But they did not compare this with the single-row method.From our long-term comparison results, the key point double-row suture could achieve no worse than single-row suture, and the range of internal rotation at abduction seemed better.

One Medial Anchor is Able to Provide Adequate Stability
The appropriate number of anchors in Bankart repair was still unclear.On the one hand, more anchors represent more stability.One review found the recurrence rate of Bankart repair decreased significantly when no less than four anchors were placed. 12Similarly, Bokshan et al. 13 concluded from their cadaveric study that an additional 6 o'clock anchor could increase the fixation strength of Bankart repair with single-row suture.The increased anchors could connect the capsulolabral complex and glenoid neck more tightly and provide more contact area for better union. 5,6However, on the other hand, more anchors were also related to more complications and motion limitations.The number of anchors had been proven a high relation to arthritis in longterm periods. 14,157][18] Moreover, McDonald et al. 7 discovered that Bankart repair brought an external limitation, especially for double-row suture according to biomechanical tests.But there were no long-term results of traditional double-row repair.Our outcomes demonstrated only one additional medial anchor did not increase additional joint pain or limited range of motion.
Our results could also prove that only one medial anchor was needed to provide enough stability as the recurrence rate was as low as 10% and excessive medial anchors in traditional double-row suture might contribute little to more stability.Many biomechanical studies about Bankart repair revealed that double-row suture could recover more natural footprint area. 5,6,19But these found that the biomechanical parameters did not express superiority in the double-row group. 19Particularly worth mentioning was Jonson who used just five anchors in double-row suture as described by Lafosse et al., 4 and the footprint area coverage percentage was 73.4%, which did not shrink a lot compared with 86% reported by Ahmad et al. 5 and 78% reported by Kim et al., 6 both of whom used eight anchors in the doublerow suture.Therefore, the excessive medial anchors did not contribute to recovering the footprint.This conformed to the cadaveric research by Itoigawa et al. 11 as mentioned above.
At the last follow-up, the internal rotation in the double-row group was significantly better than the singlerow group.One hypothesis was that the medial anchor inserted to the anteroinferior glenoid helped to restore the stability of anteroinferior glenohumeral ligament at an early stage, which could provide extra support when doing internal rotation rehabilitation.

Limitations
As a retrospective case-control study, there were some limitations.First, the rate of follow-up loss was a little high (43.6%),partly because the follow-up period was long and some patients' information had changed.Second, the shortterm follow-up data was lacking, making it difficult to analyze the union rate after the operation.Third, we were short of radiological assessments after surgery and the last followup.However, this was a long-term controlled study, and all the surgeries were performed by one experienced surgeon to make sure the surgical techniques were consistent and the results were comparable.We look forward to more complete follow-up results to supplement this study, especially the radiological data.

Prospects of Clinical Application
The key point double-row Bankart repair combined the utility of single-row suture and the effectiveness of double-row suture and avoided the potential complications.It could be one of the choices for anterior shoulder instability, especially for patients with critical glenoid bone loss who will have a high recurrence risk after receiving traditional Bankart repair.We hope there will be more clinical data to prove the effectiveness of our technique.

Conclusion
A s a new technique for Bankart lesion, key point double- row suture uses only one additional medial anchor to achieve more stability compared with single-row suture.And using one more anchor did not lead to limited range of motion.The long-term outcomes also showed its utility.The low recurrence rate and potential biomechanical advantages making it a possibly superior choice to traditional Bankart repair.

FIGURE 1
FIGURE 1 Comparison of single-row and key point double-row Bankart repair.(A) Bankart lesion; comparison of single-row (B-E) and key point double-row (F-I) Bankart repair in anterior aspect (B, F), posterior aspect (C, G), lateral aspect (D, H), and axial aspect (E, I).

TABLE 1
Baseline information of responders and non-responders (loss to follow-up) , the mean age at first dislocation was 24.8 years old, and the mean age at operation was 31.1.For the double-row group, these two ages were 20.3 and 26.7.The mean glenoid bone loss measured by CT scan before surgery was 10.7% for the single-row group and 10.4% for the double-row group.
Abbreviation: UCLA, University of California at Los Angeles.group

TABLE 2
Basic information of patients before surgery

TABLE 3
Comparison of clinical outcomes between before and after operation of each group Abbreviations: ASES, rating scale of the American shoulder and elbow surgeons; SSV, subjective shoulder value; UCLA, University of California at Los Angeles; VAS, visual analogue scale.

TABLE 4
Comparison of clinical outcomes between SR and DR group Abbreviations: ASES, rating scale of the American shoulder and elbow surgeons; SSV, subjective shoulder value; UCLA, University of California at Los Angeles; VAS, visual analogue scale.

TABLE 5
Comparison of range of motion between SR and DR group