Options for glenoid labral suture anchor fixation

Effect of cyclic loading on the ultimate tensile strength of small metallic suture anchors used for attaching artificial tendons in rabbits

Background –

Suture anchor failures can lead to revision surgeries which are costly and burdensome for patients. The durability of musculoskeletal reconstructions is therefore partly affected by the design of the suture anchors.

Purpose –

The purpose of the study was to quantify the strength of different suture anchors whose sizes are suitable for attaching artificial Achilles and tibialis cranialis tendons in a rabbit model, as well as determine the effect of cyclic loading on the anchoring strength.

Method –

Four anchors (two with embedded eyelet and two with raised eyelet, n=5 per group) were tested with cyclical loading (1000 cycles and 4.5 mm/sec) and without cycling, to inform the failure loads and mode of failure of the suture anchors. An eyebolt screw with smooth eyelet was used as a control for the test groups.

Results –

All samples in all groups completed 1000 cycles and failed via suture breakage in both test conditions. All anchors had failure loads exceeding the peak Achilles tendon force in rabbits during hopping gait. The data analysis showed an effect of anchor type on the maximum tensile force at failure (F max ) in all suture categories but not an effect of loading condition. Also, the Anika anchor had a significantly less adverse effect on suture strength compared to Arthrex anchor (p=0.015), IMEX anchor (p=0.004) and Jorvet anchor (p<0.001). We observed a greater percentage of failure at the mid-section for the anchors with the raised eyelets compared to the anchors with embedded eyelets, which all failed at the knot.

Conclusion –

Anchors with embedded eyelets had clinically preferred mode of failure with less adverse effects on suture and, may be more reliable than anchors with raised eyelets for attaching artificial Achilles and tibialis cranialis tendons in rabbits.

Arthroscopic Bankart repair: A matched cohort comparison of the modified Mason Allen method and the simple stitch method

INTRODUCTION

Arthroscopic Bankart repair (ABR) has become a standard treatment for recurrent anterior shoulder dislocation in cases with minimal bone loss. Using the standard Bankart repair technique, the failure rate has been reported to be approximately between 4 and 35%. In addition to the original injury, multiple pathologies can occur after a dislocation including a Bankart lesion, capsular redundancy and bone defects. In cases with no significant bone loss, soft tissue plays a major role in stabilizing the shoulder joint. We hypothesized that effective repair of soft tissue with good inferior capsular shifting and proper capsulolabral restoration can create a proper level of soft tissue tension so the horizontal mattress suture method should improve outcomes.

MATERIALS AND METHODS

A retrospective cohort study was conducted by reviewing the records of patients with recurrent anterior instability who underwent ABR at a single institution between January 2009 and December 2017. Demographic information, preoperative radiographic data including glenoid bone loss, Hill-Sachs width, glenoid track and other surgical details were retrieved from the medical records. The patients identified were divided into 2 groups. Group 1 had one modified Mason Allen stitch plus simple stitches, while Group 2 had only simple stitches. Data obtained from the patient included failure rate, patient satisfaction, the ROWE score and Walch-Duplay score at a minimum of 2 years after surgery. Risk factors for failure were also identified.

RESULTS

Group 1 included 50 patients (mean age 27.2 ± 9.4 years) who underwent modified Mason Allen stitch ABR (median follow-up, 59.2 months; range, 26.2-128.6 months). Group 2 included 30 patients (mean age 26.9 ± 8.5 years) who underwent simple stitch repair ABR (median follow-up, 68.0 months; range, 24.0-127.9 months). All patients met the inclusion criteria. Evaluation at the final follow-up compared Group 1 and Group 2: ROWE score (86.8 vs 76.3, P = 0.001), Walch-Duplay score (87.2 vs 82.0, P = 0.035), respectively. Failure rates were 6% in group 1 compared to 10% in group 2 (P = 0.511).

CONCLUSIONS

The modified Mason Allen stitch technique and the simple stitches technique ABR both result in excellent patient satisfaction at a minimum 2-year follow-up. Both techniques successfully restore shoulder stability, but the modified Mason Allen stitch technique results in better functional outcomes.

STUDY DESIGN

Cohort study; level of evidence, 3.

Anchor Hole Placement for Bankart Repairs and Its Interaction With Variable Size Hill–Sachs Defects-Minimizing Risk of Glenoid Rim Fractures

As the use of glenoid suture anchors in arthroscopic and open reconstruction, for instability after Bankart lesions of the shoulder, increases, an emerging problem has been the incidence of glenoid rim fractures through suture drill holes. Very little is known regarding the effect of the Hill–Sachs lesion on the glenoid's susceptibility to fracture and how drill hole location can further affect this. This study used finite element modeling techniques to investigate the risk of fracture of the glenoid rim in relation to variable sized Hill–Sachs defects impacting on the anterior glenoid edge with suture anchor holes placed in varying positions. The distribution of Von Mises (VM) stresses and the factor of safety (FOS) for each of the configurations were calculated. The greatest peak in VM stresses was generated when the glenoid was loaded with a small Hill–Sachs lesion. The VM stresses were lessened and the FOS increased (reducing likelihood of failure) with increasing size of the Hill–Sachs lesion. Placement of the suture drill holes at 2 mm from the glenoid rim showed the highest risk of failure; and when combined with a medium sized Hill–Sachs lesion, which matched the central line of the drill holes, a potentially clinically significant configuration was presented. The results of this study are useful in assisting the surgeon in understanding the interaction between the Hill–Sachs lesion size and the placement of suture anchors with the purpose of minimizing the risk of subsequent rim fracture with new injury.

The Neviaser portal for superior glenoid anchor insertion: an anatomic study

PURPOSE

To measure the angular relationship between the Neviaser portal and the superior glenoid labrum in 60 cadaveric specimens to determine whether this portal can be used for reliable anchor placement.

METHODS

The Neviaser portal of 30 left and 30 right unpaired dry cadaveric scapulae with clavicles were measured by a single observer using an analogue vernier caliper. The angular relationship between the Neviaser portal and the 12 o'clock position of the glenoid labrum was calculated.

RESULTS

13 of the 60 scapulae were excluded from analysis, because the Neviaser portal was medial to the glenoid rim making safe anchor insertion unfeasible. For the remaining 47 scapulae, the mean angles α and β were 58.2º and 57.9º, respectively. Compared with the ideal angles α and β of 30º and 0º, respectively, all the 47 Neviaser portals were more posterior (relative to the 12 o'clock position) and closer to the transverse plane, making insertion of suture anchors in the optimum position unfeasible, except for one that was within 10º of the ideal angles in both planes.

CONCLUSION

Reliable insertion of suture anchors at the 12 o'clock position of the glenoid labrum through the Neviaser portal is unfeasible in most patients.

Arthroscopic Bankart repair augmented by plication of the inferior glenohumeral ligament via horizontal mattress suturing for traumatic shoulder instability

INTRODUCTION

This study aimed to evaluate the two-year clinical outcomes of arthroscopic Bankart repair augmented by plication of the inferior glenohumeral ligament (IGHL) via horizontal mattress suturing.

METHODS

This study was a retrospective analysis of 76 arthroscopic Bankart repairs by a single surgeon from 2004 to 2008. Bioabsorbable suture anchors were used, with anchors placed at the 5:30, 4 and 3 o'clock positions of the right shoulder (correspondingly at the 6:30, 8 and 9 o'clock positions for the left shoulder). The lower most anchor was tied via horizontal mattress suture with plication of the IGHL, while the remaining two anchors were tied using simple sutures. The patients were postoperatively assessed, clinically and using the University of California Los Angeles (UCLA) shoulder rating scale.

RESULTS

The mean age of the patients at the time of presentation was 24.09 ± 7.98 years, and the mean duration of follow-up was 28.7 months. The postoperative recurrence rate of dislocation was 7.89% (six shoulders), of which five shoulders required revision surgeries. Excluding the revision cases, clinical assessment of the strength of the supraspinatus and the range of motion of the operated shoulders at two years post operation were either maintained or full in all patients. Analysis of the UCLA results showed pre- and postoperative mean scores of 25.94 ± 3.43 and 33.77 ± 3.07, respectively (p < 0.05).

CONCLUSION

Arthroscopic Bankart repair augmented by plication of the IGHL and anchored via horizontal mattress suturing is a safe and reliable treatment for shoulder instability, with good clinical outcomes and low recurrence rates.

Tissue anchor use in arthroscopic glenohumeral surgery

Arthroscopic surgery has become the mainstay of treatment of several common glenohumeral pathologies such as tears of the rotator cuff and labrum. Arthroscopic rotator cuff and labral repair provide outcomes comparable to those achieved with traditional open techniques, with the benefits of smaller incisions and less soft-tissue disruption. Development and improvement of tissue anchors and arthroscopic instrumentation has been integral to the increased popularity of arthroscopic glenohumeral repairs. Current anchors can be categorized by design and material composition. Awareness of the advantages and limitations of these implants may influence anchor selection.