All-Suture Anchors in Orthopaedic Surgery: Design, Rationale, Biomechanical Data, and Clinical Outcomes

Comparison of All-Suture Anchors and Metal Anchors in Arthroscopic Rotator Cuff Repair: Short-Term Clinical Outcomes and Anchor Pullout Risk

Objectives: Metal anchors (MA), commonly used in the early stages of rotator cuff surgical treatment development, are associated with a high risk of complications, especially in osteoporotic bone. As an alternative to rigid anchors, all-suture anchors (ASA) have been introduced for the medial row, offering promising clinical outcomes and favorable biomechanical studies. We aimed to compare the clinical outcomes of MAs and ASAs in either single-row or in medial-row suture bridge techniques in arthroscopic rotator cuff repair. Our hypothesis was that in cases where ASA was used for at least 12 months of follow-up, more favorable results would be obtained as compared to rigid anchors, and intraoperative complications such as anchor pullout would be encountered less. Methods: In this retrospective cohort analysis, we reviewed patients who underwent arthroscopic rotator cuff repair between January 2020 and December 2022. Surgeries were performed by two senior surgeons in a single tertiary center. Patients who had undergone revision surgery, had a history of previous shoulder surgeries, had massive rotator cuff tears, and partial-thickness tears; or had concomitant subscapularis tears were excluded. Preoperative and postoperative scores, including Constant-Murley (CM), Disabilities of the Arm, Shoulder, and Hand (DASH), and visual analog scale (VAS), were compared. The minimum follow-up period was 12 months. Clinical assessment of shoulder range of motion included forward flexion, abduction, internal rotation, and external rotation. Intraoperative anchor-related complications were compared. All patients underwent the same surgical technique and postoperative rehabilitation protocol. Results: A total of 142 patients (89 females, 53 males; mean age: 57.4 years) were included in the study, with 67 patients in the ASA group and 75 in the MA group. The sex distribution and mean age were similar between groups. The ASA group had 15 traumatic tears, while the MA group had 13 (p < 0.05). The mean follow-up period was 21.6 months (range 12-40 months). Preoperative CM scores were statistically better in the ASA group, but this difference was not clinically relevant (p < 0.046). The mean CM score was 75.64, the mean DASH score was 8.57, and the mean VAS was 1.38 at the postoperative period in the MA group. The mean CM score was 78.40, the mean DASH score was 9.75, and VAS was 1.59 at the postoperative period in the ASA group. Seven cases experienced anchor pullout in the MA group, and thread breakage occurred in one patient of each group (p = 0.014). The mean age of the patients with anchor pullout was significantly higher (p = 0.002). This finding was not hypothesized in the initial study design but emerged during post-hoc analysis and highlights the importance of considering bone quality in elderly patients. Conclusions: The clinical outcomes of rotator cuff repairs using all-suture anchors or metal anchors are comparable. However, ASA use may offer an advantage in elderly patients by reducing the risk of anchor pullout. Further studies assessing tendon integrity and bone quality and incorporating long-term follow-up periods are recommended to support and validate the present findings.

All-Suture Anchor Deployment Configurations in Arthroscopic Bankart Repair: A Comparative Analysis of Clinical and Radiological Outcomes

Background

All-suture anchors have various configurations during deployment and different biomechanical characteristics because of their soft anchor bodies.

Hypothesis/Purpose

This study aimed to analyze the clinical and radiological differences of all-suture anchors in arthroscopic Bankart repair based on their deployment configurations. It was hypothesized that each all-suture anchor would yield comparable clinical outcomes regardless of radiological differences in the pattern of glenoid bone reaction.

Study Design

Cohort study, Level of evidence, 3.

Methods

A total of 141 patients who underwent arthroscopic Bankart repair using all-suture anchors were enrolled. Patients were divided into 4 groups based on the configurations after deployment of the all-suture anchors used: (1) group A (38 patients)-1.3-mm all-suture anchor with a spherical configuration; (2) group B (25 patients)-1.4-mm anchor with a cloverleaf configuration; (3) group C (31 patients)-1.7-mm anchor with an omega configuration; and (4) group D (47 patients)-1.4-mm anchor with a cylindrical configuration. Clinical outcomes were evaluated preoperatively and 2 years postoperatively. The labral healing and the diameter and length of the anchor tunnel were measured on the postoperative 1-year computed tomography arthrograms.

Results

No significant difference was observed in the preoperative demographic data of the 4 groups. The all-suture anchor tunnel's mean diameter in group A (3.9 ± 0.4 mm) was significantly larger than that of groups B (3.3 ± 0.3 mm), C (3.7 ± 0.4 mm), and D (2 ± 0.3 mm; P < .01). The tunnel's length in group D (8.7 ± 1.8 mm) was significantly longer than that of groups A (4 ± 0.4 mm), B (3.3 ± 0.5 mm), and C (3.7 ± 0.6 mm; P < .01). In radiological analysis, the diameter of the suture anchors was larger in the inferior region (3.3 ± 1.3 mm) compared with the superior region (2.9 ± 1 mm; P < .01). No significant differences were found in terms of the postoperative functional outcomes and healing rates among the groups.

Conclusions

All-suture anchors with various deployment configurations produced different tunnel diameters and lengths. In addition, the diameter of the tunnel was more pronounced at the inferior region of the anterior glenoid compared with the superior region. Despite this, the deployment configurations and radiological characteristics of the all-suture anchors did not affect the clinical outcomes or occurrence of postoperative complications after Bankart repair.

Rotator cuff repair with all-suture anchor enhances biomechanical properties and tendon-bone integration in a rabbit model

Background

All-suture anchor (ASA) is a special type of suture anchor. It has been used to repair rotator cuff tears (RCTs). However, mechanical properties and tendon-bone integration at different time postoperatively remains to be unclear.

Methods

Mechanical testing and water contact angle measurements were conducted for ASA. In vitro biocompatibility was assessed using rat bone marrow stem cells (BMSCs), including live/dead cell staining and Cell Counting Kit-8 assays. ASA was implanted for rotator cuff repair (ASA group) in a New Zealand White rabbit model of RCTs, and a natural rotator cuff was used as a control (natural group). The animals were sacrificed, and tissue samples were harvested for biomechanical, radiographic, and histological analysis at 4, 8, and 12 weeks postoperatively.

Results

ASA was hydrophobic and had a strong mechanical property in vitro. The biocompatibility analysis showed that ASA had no effect on the viability of BMSCs. Mechanical testing in vivo revealed that a gradually improved failure load of ASA group was 118.0 ± 22.53N at 12 weeks postoperatively, which was recovered to the natural group. Micro-CT analysis indicated that an initial decrease in BMD and trabecular quality following ASA implantation, with a slight recovery observed at 12 weeks. Additionally, histological analysis showed the tendon-bone interface gradually integrated in the ASA group. A significant increase in tendon-bone interface scores was found from 4 weeks to 12 weeks. Tendon maturing score also improved in the ASA group, and Type I collagen content recovered to 18.58 ± 4.378 % at 12 weeks and no different from that of the natural group.

Conclusion

Rotator cuff repair with ASA in a rabbit model demonstrated the capacity to enhance biomechanical properties and tendon-bone integration.

An All-Suture Anchor Offers Equivalent Clinical Performance to an Established Solid Suture Anchor in the Arthroscopic Repair of Rotator Cuff Tears: A Prospective, Randomized, Multicenter Trial With 12-Month Follow-Up

PURPOSE

To evaluate the safety and efficacy of a next-generation, all-suture anchor in patients undergoing arthroscopic repair of rotator cuff tears, compared with that of an established solid suture anchor.

METHODS

Between April 2019 and January 2021, a prospective, comparative, randomized controlled noninferiority study conducted on people with Chinese ethnicity at 3 tertiary hospitals enrolled patients (18-75 years) requiring arthroscopic treatment for rotator cuff tears. Patients were randomized into 2 cohorts receiving either all-suture anchor or solid suture anchor and followed for 12 months. The primary outcome was the Constant-Murley score at the 12-month follow-up. Magnetic resonance imaging assessments determined the rate of retear of rotator cuff repair (defined as Sugaya classification 4 and 5). Safety evaluation was performed at all follow-up points to determine the adverse events (AEs).

RESULTS

In total, 120 patients with rotator cuff tears (mean age, 58.3 years; 62.5% female; 60 receiving all-suture anchor) underwent treatment. Five patients were lost to follow-up. Both cohorts showed significant improvement in Constant-Murley scores between baseline and 6 months (P < .001) and between 6 and 12 months (P < .001). There were no significant differences in Constant-Murley scores between the 2 cohorts at 12 months (P = .122) after operation. The retear rate at 12 months was 5.7% and 1.9% in the all-suture and solid suture anchor cohorts, respectively (P = .618). There were 2 cases of intraoperative anchor pullout, both of which were successfully resolved. No cases of postoperative reoperation or other anchor-related AEs were reported.

CONCLUSIONS

The all-suture anchor offered equivalent clinical performance to an established solid suture anchor at the 12-month follow-up in patients undergoing arthroscopic repair of rotator cuff tears. The retear rate was not statistically significantly different between the 2 cohorts.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Soft Anchors for Rotator Cuff Repair: A Review

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All-suture anchors or so-called "soft" anchors, initially adapted for labral repairs, have increased in popularity for use in rotator cuff repair because of their smaller size, decreased occupation of the footprint, improved points of fixation, ease of use, and ease of revision.

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In limited series, soft anchors have demonstrated equivalent biomechanical and clinical performance compared with hard body anchors for rotator cuff repair.

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Perianchor cyst formation can occur with both hard body and soft anchors.

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Biomechanical and clinical data support aiming for vertical angles of insertion for soft anchors.