Glenoid rim fracture after anchor repair: a report of 4 cases

Clinical and radiological outcome of all-suture anchors in shoulder and elbow surgery

Background

All-suture anchors (ASAs) are noted to cause various bone reactions when used in upper limb surgery but clinical implications are unknown.

Methods

88 shoulders and 151 elbows with a mean follow-up of 47.1 ± 17.7 months were invited for follow-up including clinical examination, questionnaires and radiographs. The anchor drill holes were radiographically assessed.

Results

At final follow up, mean DASH was 12.9 ± 13.8 and mean VAS 2.2 ± 2.4 in the shoulder population. In the elbow group mean MEPS was 91.8 ± 12.7 and mean VAS 1.5 ± 1.9. Implant-specific complications were seen in 10 elbow cases but none in the shoulder group. The mean diameter of the 1.4 mm all-suture anchor drill hole was enlarged to 2.5 ± 1.4 mm in the shoulder group and to 2.9 ± 1.0 mm in the elbow group. 50% of the 1.4 mm anchor drill holes showed abnormal morphology but these morphologic changes did not correlate with clinical outcome, complications or reoperation rate.

Discussion

Satisfying clinical outcomes are found in upper limb surgery using ASAs. Various bone changes are seen after implantation of an ASA, but these are not clinically relevant. Long-term consecutive follow-up data is required.

Arthroscopic Bankart repair: how many knotless anchors do we need for anatomic reconstruction of the shoulder?-a prospective randomized controlled study

PURPOSE

The optimal strategy for surgical repair of traumatic anterior shoulder instability remains controversial. While several study groups have reported that the clinical and radiological outcomes of arthroscopic procedures performed with two anchors are not fully adequate, these conclusions are not supported by the findings published in other studies. A prospective randomized study was conducted to compare the structural and clinical outcomes of surgical procedures involving two vs. three anchors.

METHODS

Patients who underwent arthroscopic Bankart repair were randomly assigned to either Group I, which underwent procedures involving two double-loaded 3.5-mm knotless anchors, or Group II, which underwent procedures involving three single-loaded 2.9-mm knotless anchors. All patients underwent bilateral MRI assessments at a minimum of 12 months and clinical assessment at a minimum of 24 months postoperatively. To evaluate the reconstruction of the labral capsular ligamentous complex (LCLC), the labrum-glenoid height index (LGHI), restored labral height (LH), and labral slope (LS) were measured for both shoulders. For clinical assessment, the redislocation rate and functional outcome scores (Constant score (CS), American Shoulder and Elbow Surgeon score (ASES), Walch Duplay score (WDS), and Rowe score (RS)) were evaluated at follow-up visits.

RESULTS

Bankart repair with two knotless anchors showed lower values for anterior reconstruction of the LCLC compared to the uninjured contralateral shoulder. Likewise, significant differences were noted when comparing these measurements to those from patients who underwent reconstruction with three anchors. No differences were demonstrated with regard to the reconstruction of the inferior LCLC. Clinical assessment showed good to excellent results in both groups. In total, three patients experienced redislocation of the shoulder: two in group I and one in group II. No significant differences were found with respect to clinical outcomes and redislocation rates.

CONCLUSION

Bankart repair with both two and three knotless anchors results in effective anatomical reconstruction of the labral capsular ligamentous complex. Although the two-anchor technique yields significantly lower values for the anterior portion compared with the contralateral side, none of these differences reach clinical relevance as per our original definition.

Knotless All-Suture, Soft Anchor Bankart Repair Results in Excellent Patient-Reported Outcomes, High Patient Satisfaction, and Acceptable Recurrent Instability Rates at Minimum 2-Year Follow-Up

PURPOSE

The purpose of this study was to evaluate minimum 2-year outcomes after arthroscopic knotless all-suture soft anchor Bankart repair in patients with anterior shoulder instability.

METHODS

This was a retrospective case series of patients who underwent Bankart repair using soft, all-suture, knotless anchors (FiberTak anchors) from 10/2017 to 06/2019. Exclusion criteria were concomitant bony Bankart lesion, shoulder pathology other than that involving the superior labrum or long head biceps tendon, or previous shoulder surgery. Scores collected preoperatively and postoperatively included SF-12 PCS, ASES, SANE, QuickDASH, and patient satisfaction with various sports participation questions. Surgical failure was defined as revision instability surgery or redislocation requiring reduction.

RESULTS

A total of 31 active patients, 8 females and 23 males, with a mean age of 29 (range: 16-55) years were included. At a mean of 2.6 years (range: 2.0-4.0), patient-reported outcomes significantly improved over preoperative levels. ASES score improved from 69.9 to 93.3 (P < .001), SANE improved from 56.3 to 93.8 (P < .001), QuickDASH improved from 32.1 to 6.3 (P < .001) and SF-12 PCS improved from 45.6 to 55.7 (P < .001). Median patient postoperative satisfaction was 10/10 (range: 4-10). Patients reported a significant improvement sports participation (P < .001), pain with competition (P = .001), ability to compete in sports (P < .001), painless use of arm for overhead activities (P = .001), and shoulder function during recreational sporting activity (P < .001). Postoperative shoulder redislocations were reported in 4 cases (12.9%)-all after major trauma-with 2 patients progressing to Latarjet (6.45%) at 2 and 3 years postoperatively. There were no cases of postoperative instability without major trauma.

CONCLUSIONS

Knotless all-suture, soft anchor Bankart repair resulted in excellent patient-reported outcomes, high patient satisfaction, and acceptable recurrent instability rates, in this series of active patients. Redislocation after arthroscopic Bankart repair with a soft, all-suture anchor only occurred after return to competitive sports with new high-level trauma.

STUDY DESIGN

Level IV, retrospective cohort study.

Repair integrity and functional outcomes of arthroscopic repair in chronic anterior shoulder instability: single-loaded versus double-loaded single-row repair

INTRODUCTION

This study compared the clinical outcome and repair integrity of single-loaded and double-loaded single-row arthroscopic repair of chronic anterior shoulder instability.

MATERIALS AND METHODS

Fifty consecutive chronic anterior shoulder instability cases treated by arthroscopic labral repair were included. A single-loaded single-row technique was used in the first 25 consecutive shoulders, and a double-loaded single-row technique was used in the next 25 consecutive shoulders. The number of suture anchors was 4 in the shoulders that underwent single-loaded repair and 3 in the shoulders that underwent double-loaded repair. 42 shoulders (84.0%) followed up clinical outcomes were evaluated a minimum 2 years (mean 28.5 months; range 24-46) postoperatively. The postoperative labral repair integrity was evaluated by MDCT-arthrogram at a minimum 6 months postoperatively.

RESULTS

At the final follow-up, the average UCLA, ASES, Constant, Rowe score, VAS pain score, and VAS for instability scores improved significantly, to 33.05, 92.33, 89.05, 94.86, 0.90 and 0.52, respectively, in the single-loaded group and to 32.19, 90.10, 89.05, 94.52, 0.90, and 0.86, respectively, in the double-loaded group. The clinical scores improved in both groups postoperatively (all P < 0.05); however, there was no significant difference between the two groups at final follow-up (P = 0.414, 0.508, 1.000, 0.917, 1.000, and 0.470, respectively). The re-tear rate was 2 (9.5%) in the shoulders that underwent single-loaded repair and 3 (14.3%) in the shoulders that underwent double-loaded repair; this difference was statistically not significant (P = 0.634).

CONCLUSION

The double-loaded single-row technique resulted in comparable clinical outcomes, and re-tear rate compared with the single-loaded single-row technique in chronic anterior shoulder instability at short-term follow-up. Number of used suture anchor in double-loaded single-row technique was fewer than that of single-loaded single-row technique.

LEVEL OF EVIDENCE

Comparative retrospective study, level III.

Anchor Site Fracture Following Arthroscopic Rotator Cuff Repair - A Case Report and Review of the Literature

Introduction

Fractures at the anchor site following arthroscopic rotator cuff repair are rare and only a few case reports have been described. We report two additional well-documented cases of this uncommon post-operative complication and provide a review of the current literature.

Case Report

A 48-year-old male underwent arthroscopic rotator cuff repair (ARCR) due to a massive rotator cuff tear. Nine weeks postoperatively, the patient suffered a humeral head fracture at the anchor site of the ARCR after trauma. Despite subsequent surgical treatment with open reduction and internal fixation, the patient demonstrates with excellent functional outcome scores at 2-year follow-up.

Conclusion

Humeral head fractures are a rare complication after ARCR. The use of intraosseous anchors requires careful consideration regarding positioning and quantity used.

Serial Changes in Perianchor Cysts Following Arthroscopic Labral Repair Using All-Suture Anchors

Backgroud

Changes in perianchor cysts around the all-suture anchors, which demonstrate distinguished features from the biocomposite anchors, have not been revealed sufficiently. The purpose of this study was to investigate serial changes of perianchor cysts according to the location of the inserted anchor in the glenoid in arthroscopic labral repair using all-suture anchors.

Methods

We enrolled 43 patients who underwent computed tomography (CT) immediately postoperatively and CT arthrogram (CTA) at 1 year or 2 years after arthroscopic labral repair using a 1.3-mm all-suture anchor for recurrent anterior shoulder dislocation with or without a superior labral tear from anterior to posterior and a posterior labral tear. The mean diameter and tissue density (HU) of perianchor cysts were measured depending on the location in the glenoid. Clinical outcomes, labral healing, and redislocation rate were evaluated at 2 years after surgery.

Results

On functional assessment, the mean American Shoulder and Elbow Surgeons score and Rowe score improved statistically significantly after surgery (from 47.9 ± 14.3 preoperatively to 90.1 ± 9.6 postoperatively and from 45.3 ± 12.4 preoperatively to 92.2 ± 10.1 postoperatively, respectively; p < 0.01). Postoperative redislocations were found in 2 patients (4.7%). In radiological evaluation, the mean diameter of perianchor cysts at postoperative 1 year (3.24 ± 0.65 mm) was significantly larger than the immediate postoperative diameter; however, there was no significant difference between postoperative 1 year and 2 years (3.23 ± 0.57 mm). Tissue density at the center of cysts demonstrated no significant difference between 1 and 2 year postoperatively (107.7 ± 29.8 HU [superior], 99.7 ± 31.7 HU [anteroinferior], and 105.1 ± 25.0 HU [posterior] vs. 109.1 ± 26.1 HU [superior], 106.4 ± 30.3 HU [anteroinferior], and 111.0 ± 32.9 HU [posterior]). The mean diameter of perianchor cysts in the anteroinferior position was largest compared with that in superior or posterior positions.

Conclusions

Perianchor cysts associated with all-suture anchors enlarged significantly within 1 year after arthroscopic labral repair regardless of the insertion location in the glenoid. However, the size and tissue density of perianchor cysts were similar at postoperative 1 and 2 years, and satisfactory stability and clinical outcomes were obtained.

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.

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.

"Postage Stamp" Fractures: A Systematic Review of Patient and Suture Anchor Profiles Causing Anterior Glenoid Rim Fractures After Bankart Repair

PURPOSE

To systematically review patient and technical risk factors for anterior glenoid rim fractures through suture anchor points (i.e. "postage stamp") after arthroscopic Bankart repair.

METHODS

An independent, duplicate search of Embase, Medline, and Web of Science databases, in addition to the past 5-year annual meeting abstracts of several prominent shoulder meetings, was conducted according to R-AMSTAR and Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines to identify English-language studies reporting this complication.

RESULTS

A screen of 2,833 studies yielded 6 for inclusion herein. Data across 43 patients, aged 14 to 61 years (mean 24.4), 5% female, and who were followed for 4 to 108 months postoperatively, were reviewed. Only 1 of 6 studies (n = 2) reported postage stamp fracture in female patients. Median time from initial surgery to fracture ranged from 12 to 24 months. Five of 6 studies (n = 32) reported a median age at initial surgery of 25 years or younger (range 17-35). Four of 6 studies (n = 30) reported fracture mostly after sport involvement. All studies (n = 35) reported initial fixation with a median of 3 anchors or more, 3 of 5 studies (n = 26) reported fracture entirely after conventional knot-tying anchors, and 5 of 6 studies (n = 24) reported more fractures after absorbable suture anchor use. Fractures occurred entirely through anchor holes in 5 of 6 studies (n = 29) and mostly after osteolysis in 3 of 4 studies (n = 19). Management strategies after fracture included revision arthroscopic Bankart repair or open Bristow/Latarjet procedures.

CONCLUSION

Postage stamp fractures were reported frequently in patients who were male, age 25 years or younger, and participants in sporting activities and in fractures initially stabilized with 3 or more anchors or conventional knot-tying anchors or that experienced osteolysis around anchor sites.

LEVEL OF EVIDENCE

Level IV, systematic review of level III and IV studies.

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.

Comparison of Clinical Outcomes and Computed Tomography Analysis for Tunnel Diameter After Arthroscopic Bankart Repair With the All-Suture Anchor and the Biodegradable Suture Anchor

PURPOSE

To compare the clinical outcomes and radiological findings at the anchor site after arthroscopic Bankart repair with all-suture anchors and biodegradable suture anchors in patients with recurrent anterior shoulder dislocation.

METHODS

The patients who underwent arthroscopic Bankart repair were divided into 2 groups depending on the type of the suture anchor used in different periods. Power analysis was designed based on the postoperative Rowe score. Clinical outcomes, including the Rowe score, American Shoulder and Elbow Surgeons score, subjective instability, and redislocation rates were evaluated. In all patients enrolled, the tunnel diameter of the anchor was assessed with computed tomography arthrogram at 1 year postoperatively. The Institutional Review Board of Ewha Womans University approved this study (no. EUMC 2017-05-058).

RESULTS

A total of 67 patients were enrolled: 33 underwent surgery with a 1.3-mm (single-loaded) or 1.8-mm (double-loaded) all-suture anchor (group A), and 34 underwent surgery with a 3.0-mm biodegradable anchor (10.8 mm in length, 30% 1,2,3-trichloropropane/70% poly-lactide-co-glycolic acid) (group B). There were no significant differences in clinical outcomes between groups A and B in the American Shoulder and Elbow Surgeons score (preoperatively, 51.2 ± 13.7 vs 47.7 ± 12.2; 2 years postoperatively, 88.5 ± 12.3 vs 89.7 ± 10.9; P = .667) and Rowe score (preoperatively, 41.4 ± 10.5 vs 41.3 ± 9.4; 2 years postoperatively, 87.9 ± 14.9 vs 88.5 ± 14.6; P = .857). Postoperative redislocation (6.1% vs 5.9%, P = .682) and subjective instability rate (12.2% vs 17.7%, P = .386) of both groups showed no significant difference. Average tunnel diameter increment was significantly greater with the 1.8-mm all-suture anchor (2.8 ± 0.9 mm) than the 1.3-mm all-suture anchor (1.2 ± 0.8 mm) and 3.0-mm biodegradable anchor (0.8 ± 1.2 mm) (P < .001).

CONCLUSIONS

Arthroscopic Bankart repair with the all-suture anchor showed comparable clinical outcomes and postoperative stability as the conventional biodegradable suture anchor at 2 years after surgery. Tunnel diameter increment of the all-suture anchor was significantly greater than that of the biodegradable suture anchor at the 1-year computed tomography analysis. Although tunnel diameter increment was greater with the all-suture anchor, it did not influence the clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

An Anatomic and Biomechanical Comparison of Bankart Repair Configurations

BACKGROUND

Suture anchor repair for anterior shoulder instability can be performed using a number of different repair techniques, but none has been proven superior in terms of anatomic and biomechanical properties. Purpose/Hypothesis: The purpose was to compare the anatomic footprint coverage and biomechanical characteristics of 4 different Bankart repair techniques: (1) single row with simple sutures, (2) single row with horizontal mattress sutures, (3) double row with sutures, and (4) double row with labral tape. The hypotheses were as follows: (1) double-row techniques would improve the footprint coverage and biomechanical properties compared with single-row techniques, (2) horizontal mattress sutures would increase the footprint coverage compared with simple sutures, and (3) repair techniques with labral tape and sutures would not show different biomechanical properties.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-four fresh-frozen cadaveric specimens were dissected. The native labrum was removed and the footprint marked and measured. Repair for each of the 4 groups was performed, and the uncovered footprint was measured using a 3-dimensional digitizer. The strength of the repair sites was assessed using a servohydraulic testing machine and a digital video system to record load to failure, cyclic displacement, and stiffness.

RESULTS

The double-row repair techniques with sutures and labral tape covered 73.4% and 77.0% of the footprint, respectively. These percentages were significantly higher than the footprint coverage achieved by single-row repair techniques using simple sutures (38.1%) and horizontal mattress sutures (32.8%) ( P < .001). The footprint coverage of the simple suture and horizontal mattress suture groups was not significantly different ( P = .44). There were no significant differences in load to failure, cyclic displacement, or stiffness between the single-row and double-row groups or between the simple suture and horizontal mattress suture techniques. Likewise, there was no difference in the biomechanical properties of the double-row repair techniques with sutures versus labral tape.

CONCLUSION

Double-row repair techniques provided better coverage of the native footprint of the labrum but did not provide superior biomechanical properties compared with single-row repair techniques. There was no difference in footprint coverage or biomechanical strength between the simple suture and horizontal mattress suture repair techniques.

CLINICAL RELEVANCE

Although the double-row repair techniques had no difference in initial strength, they may improve healing in high-risk patients by improving the footprint coverage.

Postoperative Recurrence of Instability Due to New Anterior Glenoid Rim Fractures After Arthroscopic Bankart Repair

BACKGROUND

Computed tomography (CT) sometimes reveals a new fracture of the anterior glenoid rim in patients with postoperative recurrence of instability after arthroscopic Bankart repair using suture anchors, but there have been few previous reports about such fractures.

HYPOTHESIS

The placement of a large number of suture anchors during arthroscopic Bankart repair might be associated with a new glenoid rim fracture.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Screw-in metal suture anchors were used until June 2011 and suture-based soft anchors from July 2011. A follow-up of at least 2 years was conducted for 128 shoulders treated using metal anchors (metal anchor group) and 129 shoulders treated using soft anchors (soft anchor group). The frequency and features of new glenoid rim fractures were investigated, and the influence of the number of suture anchors and other factors on fractures was also assessed.

RESULTS

There were 19 shoulders (14.8%) with postoperative recurrence in the metal anchor group and 23 shoulders (17.8%) in the soft anchor group. Among 37 shoulders evaluated by CT at recurrence, a new glenoid rim fracture was detected in 13 shoulders (35.1%; 5 shoulders in the metal anchor group and 8 shoulders in the soft anchor group). A fracture at the anchor insertion site was recognized in 4 shoulders from the metal anchor group and 6 shoulders from the soft anchor group, although linear fractures connecting several anchor holes were only seen in the soft anchor group. While new glenoid fractures occurred regardless of the number of suture anchors used, new fractures were significantly more frequent in teenagers at surgery and in junior high school or high school athletes. Such fractures did not only occur in contact athletes but were also found in overhead athletes.

CONCLUSION

Postoperative recurrence of instability associated with a new glenoid rim fracture along the suture anchor insertion site was frequent after arthroscopic Bankart repair. These fractures might be related to placing multiple soft suture anchors in a linear arrangement.

Biomechanical Comparison of a First- and a Second-Generation All-Soft Suture Glenoid Anchor

Background:

All–soft tissue suture anchors provide advantages of decreased removal of bone and decreased glenoid volume occupied compared with traditional tap or screw-in suture anchors. Previous published data have led to biomechanical concerns with the use of first-generation all-soft suture anchors.

Purpose/Hypothesis:

The purpose of this study was to evaluate the load to 2-mm displacement and ultimate load to failure of a second-generation all-soft suture anchor, compared with a first-generation anchor and a traditional PEEK (polyether ether ketone) anchor. The null hypothesis was that the newer second-generation anchor will demonstrate no difference in loads to 2-mm displacement after cycling compared with first-generation all-soft suture anchors.

Study Design:

Controlled laboratory study.

Methods:

Twenty human cadaveric glenoids were utilized to create 97 total suture anchor sites, and 1 of 3 anchors were randomized and placed into each site: (1) first-generation all-soft suture anchor (Juggerknot; Biomet), (2) second-generation all-soft suture anchor (Suturefix; Smith & Nephew), and (3) a control PEEK anchor (Bioraptor; Smith & Nephew). After initial cyclic loading, load to 2 mm of displacement and ultimate load to failure were measured for each anchor.

Results:

After cyclic loading, the load to 2-mm displacement was significantly less in first-generation anchors compared with controls (P < .01). However, the load to 2-mm displacement was significantly greater in second-generation anchors compared with controls (P < .01). There was no difference in ultimate load to failure between the first- and second-generation all-soft suture anchors (P > .05).

Conclusion:

The newer generation all-soft suture anchors with a theoretically more rigid construct and deployment configuration demonstrate biomechanical characteristics (specifically, with load to 2-mm displacement after cyclic loading) that are improved over first-generation all-soft suture anchors and similar to a traditional solid tap-in anchor. The configuration of these newer generation all-soft suture anchors appears to mitigate the biomechanical concerns of decreased load to failure with first-generation all–soft tissue suture anchors.

Clinical Relevance:

The theoretical advantages of all-soft anchors may be particularly valuable in revision surgery or in cases where multiple anchors are being placed into a small anatomic area.

All-Suture Anchors: Biomechanical Analysis of Pullout Strength, Displacement, and Failure Mode

PURPOSE

To evaluate the biomechanical and design characteristics of all-suture anchors.

METHODS

All-suture anchors were tested in fresh porcine cortical bone and biphasic polyurethane foam blocks by cyclic loading (10-100 N for 200 cycles), followed by destructive testing parallel to the insertion axis at 12.5 mm/s. Endpoints included ultimate failure load, displacement at 100 and 200 cycles, stiffness, and failure mode. Anchors tested included JuggerKnot (1.4, 1.5, and 2.8), Iconix (1, 2, and 3), Y-knot (1.3, 1.8, and 2.8), Q-Fix (1.8 and 2.8), and Draw Tight (1.8 and 3.2).

RESULTS

The mean ultimate failure strength of the triple-loaded anchors (564 ± 42 N) was significantly greater than the mean ultimate failure strength of the double-loaded anchors (465 ± 33 N) (P = .017), and the double-loaded anchors were stronger than the single-loaded anchors (256 ± 35 N) (P < .0001). No difference was found between the results in porcine bone and biphasic polyurethane foam. None of these anchors demonstrated 5 mm or 10 mm of displacement during cyclic loading. The Y-Knot demonstrated greater displacement than the JuggerKnot and Q-Fix (P = .025) but not the Iconix and Draw Tight (P > .05). The most common failure mode varied and was suture breaking for the Q-Fix (97%), JuggerKnot (81%), and Iconix anchors (58%), anchor pullout with the Draw Tight (76%), whereas the Y-Knot was 50% suture breaking and 50% anchor pullout.

CONCLUSIONS

The ultimate failure load of an all-suture anchor is correlated directly with its number of sutures. With cyclic loading, the Y-Knot demonstrated greater displacement than the JuggerKnot and Q-Fix but not the Iconix and Draw Tight. JuggerKnot (81%) and Q-Fix (97%) anchors failed by suture breaking, whereas the Draw Tight anchor failed by anchor pullout (76%).

CLINICAL RELEVANCE

All-suture anchors vary in strength and performance, and these factors may influence clinical success. Biphasic polyurethane foam is a validated model for suture anchor testing.

Effect of Additional Sutures per Suture Anchor in Arthroscopic Bankart Repair: A Review of Single-loaded Versus Double-loaded Suture Anchors

PURPOSE

To directly compare single-loaded suture anchors (SSA) with double-loaded suture anchors (DSA) to help surgeons optimize the operative technique, time, and cost of Bankart repairs.

METHODS

A literature review was performed using the PubMed and SCOPUS databases. Studies that directly compared SSA and DSA for Bankart repairs, or indirectly compared them by collecting relevant data despite a different objective, were included.

RESULTS

A total of two studies were included, both of which were cadaveric laboratory studies. A total of 28 shoulders were tested. Tests conducted include loading to failure and cyclic loading. One study found SSA to be biomechanically equivalent to DSA, and one found DSA to be superior.

CONCLUSIONS

Based on limited cadaveric study, DSA are at least equivalent biomechanically to SSA, and may be superior. By using DSA, surgeons create repair constructs that are as strong as, or stronger than, those made with SSA, but with fewer anchors. This reduces the amount of holes drilled and implants placed in the glenoid, while also minimizing cost.

CLINICAL RELEVANCE

Quantifying the benefit of additional sutures in a suture anchor can help optimize the quality of repair, time, and cost in arthroscopic shoulder repair.

Arthroscopic Bankart repair for recurrent shoulder instability: A retrospective study of 86 cases

The purpose of our study was to retrospectively evaluate the outcomes of arthroscopic Bankart repair in 86 patients, who met the inclusion criteria of at least one episode of shoulder dislocation, with a minimum follow-up of one year. Outcome was measured by the use of Western Ontario Shoulder Instability (WOSI) score. At the end of our study, the recurrence rate was 7%. Young age (p = 0.016) and ligamentous laxity (p = 0.003) were associated with recurrence. Arthroscopic Bankart repair is a reliable treatment method, with good clinical outcomes. Patients with younger age or with ligamentous laxity were at the greatest risk of recurrence.

Triple labrum tears repaired with the JuggerKnot™ soft anchor: Technique and results

Purpose:

The 2-year outcomes of patients undergoing repair of triple labrum tears using an all-suture anchor device were assessed.

Materials and Methods:

Eighteen patients (17 male, one female; mean age 36.4 years, range: 14.2-62.3 years) with triple labrum tears underwent arthroscopic repair using the 1.4 mm JuggerKnot Soft Anchor (mean number of anchors 11.5, range: 9-19 anchors). Five patients had prior surgeries performed on their operative shoulder. Patients were followed for a mean of 2.0 years (range: 1.6-3.0 years). Constant–Murley shoulder score (CS) and Flexilevel scale of shoulder function (FLEX-SF) scores were measured, with preoperative and final postoperative mean scores compared with a paired Student's t-test (P < 0.05). Magnetic resonance imaging (MRI) was also performed at final postoperative.

Results:

Overall total CS and FLEX-SF scores increased from 52.9 ± 20.4 to 84.3 ± 10.7 (P < 0.0001) and from 29.3 ± 4.7 to 42.0 ± 7.3 (P < 0.0001), respectively. When divided into two groups by whether or not glenohumeral arthrosis was present at the time of surgery (n = 9 each group), significant improvements in CS and FLEX-SF were obtained for both groups (P < 0.0015). There were no intraoperative complications. All patients, including contact athletes, returned to their preinjury level of sports activity and were satisfied. MRI evaluation revealed no instances of subchondral cyst formation or tunnel expansion. Anchor tracts appeared to heal with fibrous tissue, complete bony healing, or combined fibro-osseous healing.

Conclusion:

Our results are encouraging, demonstrating a consistent healing of the anchor tunnels through arthroscopic treatment of complex labrum lesions with a completely suture-based implant. It further demonstrates a meaningful improvement in patient outcomes, a predictable return to activity, and a high rate of patient satisfaction.

Level of Evidence:

Level IV case series.

Anterior Glenoid Rim Fracture Following Use of Resorbable Devices for Glenohumeral Stabilization

BACKGROUND

Resorbable anchors are widely used in arthroscopic stabilization of the shoulder as a means of soft tissue fixation to bone. Their function is to ensure repair stability until they are replaced by host tissue. Complications include inflammatory soft tissue reactions, cyst formation, screw fragmentation in the joint, osteolytic reactions, and enhanced glenoid rim susceptibility to fracture.

PURPOSE

To evaluate resorption of biodegradable screws and determine whether they induce formation of areas with poor bone strength that may lead to glenoid rim fracture even with minor trauma.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study evaluated 12 patients with anterior shoulder instability who had undergone arthroscopic stabilization with the Bankart technique and various resorbable anchors and subsequently experienced redislocation. The maximum interval between arthroscopic stabilization and the new dislocation was 52 months (mean, 22.16 months; range, 12-52 months). The mean patient age was 31.6 years (range, 17-61 years). The persistence or resorption of anchor holes; the number, area, and volume of osteolytic lesions; and glenoid erosion/fracture were assessed using computed tomography scans taken after redislocation occurred.

RESULTS

Complete screw resorption was never documented. Osteolytic lesions were found at all sites (mean diameter, 5.64 mm; mean depth, 8.09 mm; mean area, 0.342 cm(2); mean volume, 0.345 cm(3)), and all exceeded anchor size. Anterior glenoid rim fracture was seen in 9 patients, even without high-energy traumas (75% of all recurrences).

CONCLUSION

Arthroscopic stabilization with resorbable devices is a highly reliable procedure that is, however, not devoid of complications. In all 12 patients, none of the different implanted anchors had degraded completely, even in patients with longer follow-up, and all induced formation of osteolytic areas. Such reaction may lead to anterior glenoid rim fracture according to the literature and as found in 75% of the study patients with local osteolysis (9/12). Reducing anchor number and/or size may reduce the risk of osteolytic areas and anterior glenoid rim fracture.

The histologic and biomechanical response of two commercially available small glenoid anchors for use in labral repairs

BACKGROUND

This study examined histologic characteristics and biomechanical performance of 2 commercially available, small glenoid anchors.

METHODS

Adult research dogs (n = 6) were used for histologic analysis. Anchors were inserted into the lateral rim of the glenoid using the manufacturer's protocol. The dogs were humanely euthanatized 8 weeks after anchor implantation, and the glenoids were collected for histologic analysis. Bone socket width data were compared for statistically significant (P < .05) differences. In addition, 4 matched pairs (n = 8) of human cadaveric glenoids were instrumented with 1 BioComposite SutureTak (Arthrex, Naples, FL, USA) and 1 JuggerKnot (Biomet, Warsaw, IN, USA) suture anchor in the anterior-inferior quadrant. Anchor constructs were preloaded to 5 N, cycled from 5 to 25 N for 100 cycles, and then pulled to failure.

RESULTS

All JuggerKnot anchor sites were cyst-like cavities with a rim of dense lamellar bone. All BioComposite SutureTak anchor sites contained intact anchors with close approximation of anastomosing trabeculae of lamellar bone. At 8 weeks after implantation, mean socket width of the JuggerKnot anchor sites was 6.3 ± 2.5 mm, which was significantly (P = .013) larger than the mean socket width of 2.7 ± 0.7 mm measured for the BioComposite SutureTak anchor sites. The JuggerKnot anchor demonstrated larger displacements during subfailure cyclic loading (2.9 ± 1.0 mm compared with 1.3 ± 0.4 mm) and load to failure tests (13.7 ± 6.6 mm compared with 3.2 ± 0.5 mm). Statistical differences (P < .01) existed in every category except ultimate load.

CONCLUSIONS

Based on the biomechanical in human bone and histologic findings in canine subjects, the all-suture anchor may be at risk for clinical failure.

Recycling Suture Limbs from Knotless Suture Anchors for Arthroscopic Shoulder Stabilization

Recurrent shoulder instability often leads to labral abnormality that requires surgical intervention that may require fixation with suture anchors. The proposed surgical technique allows the surgeon to achieve 2 points of fixation around the labrum and/or capsule with a single suture secured to the glenoid with a knotless anchor. Instead of cutting and discarding the residual suture limbs after anchor insertion, this technique uses the residual suture limbs of the knotless anchor for a second suture pass. This technique (1) creates a more cost- and time-efficient surgical procedure than using multiple single-loaded anchors or double-loaded anchors, (2) decreases the known risk of glenoid fracture from the stress riser at the implant tips of multi-anchor repairs by reducing the number of anchors required for stabilization, (3) decreases the surgical time compared with the use of double-loaded anchors through simpler suture management and less knot tying, (4) allows for the secure reapproximation of the labrum to the glenoid while offering a convenient option for capsulorrhaphy without the need to insert another anchor, and (5) yields more points of soft-tissue fixation with fewer anchors drilled into the glenoid.

Inferior suture anchor placement during arthroscopic Bankart repair: influence of portal placement and curved drill guide

BACKGROUND

During arthroscopic Bankart repair, inferior anchor placement is critical to a successful outcome. Low anterior anchors may be placed with a standard straight guide via midglenoid portal, with a straight guide with trans-subscapularis placement, or with curved guide systems. Purpose/

HYPOTHESIS

To evaluate glenoid suture anchor trajectory, position, and biomechanical performance as a function of portal location and insertion technique. It is hypothesized that a trans-subscapularis portal or curved guide will improve anchor position, decrease risk of opposite cortex breach, and confer improved biomechanical properties.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty cadaveric shoulders were randomized to 1 of 3 groups: straight guide, midglenoid portal (MG); straight guide, trans-subscapularis portal (TS); and curved guide, midglenoid portal (CG). Three BioRaptor PK 2.3-mm anchors were inserted arthroscopically, with an anchor placed at 3, 5, and 7 o'clock. Specimens were dissected with any anchor perforation of the opposite cortex noted. An "en face" image was used to evaluate actual anchor position on a clockface scale. Each suture anchor underwent cyclic loading (10-60 N, 250 cycles), followed by a load-to-failure test (12.5 mm/s). Fisher exact test and mixed effects regression modeling were used to compare outcomes among groups.

RESULTS

Anchor placement deviated from the desired position by 9.9° ± 11.4° in MG specimens, 11.1° ± 13.8° in TS, and 13.1° ± 14.5° in CG. After dissection, opposite cortex perforation at 5 o'clock occurred in 50% of MG anchors, 0% of TS, and 40% of CG. Of the 90 anchors tested, 17 (19%) failed during cyclic loading, with a similar failure rate across groups (P = .816). The maximum load was significantly higher for the 3-o'clock anchors when compared with the 5-o'clock anchors, regardless of portal or guide (P = .021). For the 5-o'clock position, there were significantly fewer "out" anchors in the TS group versus the CG or MG group (P = .038). There was no statistically significant difference in maximum load among groups at 5 o'clock.

CONCLUSION

Accuracy in suture anchor placement during arthroscopic Bankart repair can vary depending on both portal used and desired position of anchor. The results of the current study indicate that there was no difference in ultimate load to failure among anchors inserted via a midglenoid straight guide, midglenoid curved guide, or percutaneous trans-subscapularis approach. However, midglenoid portal anchors drilled with a straight or curved guide and placed at the 5-o'clock position had significant increased risk of opposite cortex perforation compared with trans-subscapularis percutaneous insertion, with no apparent biomechanical detriment.

CLINICAL RELEVANCE

The findings from this study will facilitate improved understanding of risks and benefits of several techniques for arthroscopic shoulder instability treatment with regard to suture anchor fixation.

Outcomes of two surgical revision techniques for recurrent anterior shoulder instability following selective capsular repair

INTRODUCTION

Conventional capsulolabral reconstruction for anterior shoulder instability fails with recurrent instability in up to 23% of cases. Few studies have evaluated surgical revision strategies and outcomes. The objective of this study was to evaluate clinical and radiographic outcomes in a homogeneous series of surgical revisions after selective capsular repair (SCR).

HYPOTHESIS

Observed anatomic lesions can guide the choice between repeat SCR and coracoid transfer (Latarjet procedure).

MATERIALS AND METHODS

From January 2005 to January 2009, 11 patients with trauma-related recurrent anterior shoulder instability (episodes of subluxation and/or dislocation) after SCR were included. Mean age was 31 years (range, 19-45 years). At revision, a glenoid bony defect was present in six patients. Repeat SCR was performed in five patients and coracoid transfer in six patients.

RESULTS

After a mean follow-up of 40 months (range, 24-65 months), no patient had experienced further episodes of instability. However, four patients had a positive apprehension test. External rotation decreased significantly by more than 20° after both techniques. The Simple Shoulder Test, Walch-Duplay, and Rowe scores were 10.5, 79, and 85, respectively. No patient had a subscapularis tear. Of these 11 patients, nine were able to resume their sporting activities and eight reported being satisfied or very satisfied with the subjective outcome. Radiographs showed fibrous non-union of the coracoid transfer in one patient.

CONCLUSION

In patients with recurrent anterior shoulder instability after SCR, repeat SCR and coracoid transfer produce similarly satisfactory outcomes. The size of the glenoid bone defect may be the best criterion for choosing between these two procedures. However, open revision surgery may decrease the range of motion, most notably in external rotation.

LEVEL OF EVIDENCE

Level IV.

Biomechanical analysis of a double-loaded glenoid anchor configuration: can fewer anchors provide equivalent fixation?

BACKGROUND

Bankart repair with multiple anchor holes concentrated in the anterior-inferior glenoid may contribute to glenoid weakening and potentially may induce glenoid failure.

PURPOSE

To compare the biomechanical strength of a Bankart repair construct that used 3 single-loaded suture anchors versus a repair construct that used 2 double-loaded suture anchors.

STUDY DESIGN

Comparative laboratory study.

METHODS

A standard Bankart lesion was created in 18 human cadaveric shoulders (9 matched pairs). Within each matched pair, 1 repair construct used 3 single-loaded anchors, whereas the other used 2 double-loaded suture anchors. Measured outcomes (load, stiffness, and energy absorbed) were recorded at failure and at 2 mm of labral displacement. Constructs were loaded to failure with a materials testing device that had differential variable reluctance transducers for displacement measurements.

RESULTS

The double-loaded anchor construct had a significantly higher ultimate tensile load (944 ± 231 vs 784 ± 287 N; P = .03). For the other measures (load at 2 mm of displacement, energy absorbed at failure and at 2 mm of displacement and stiffness), there were no significant differences between tested constructs.

CONCLUSION

A Bankart repair construct that used 2 double-loaded anchors was either superior to or equal to a repair construct that used 3 single-loaded anchors in all measured outcomes.

CLINICAL RELEVANCE

Using 2 double-loaded suture anchors for a Bankart repair may limit anchor holes in the glenoid and reduce the risk of postsurgical glenoid fracture while providing a stable repair construct.

Complications of bioabsorbable suture anchors in the shoulder

The development of the suture anchor has played a pivotal role in the transition from open to arthroscopic techniques of the shoulder. Various suture anchors have been manufactured that help facilitate the ability to create a soft tissue to bone repair. Because of reported complications of loosening, migration, and chondral injury with metallic anchors, bioabsorbable anchors have become increasingly used among orthopaedic surgeons. In this review, the authors sought to evaluate complications associated with bioabsorbable anchors in or about the shoulder and understand these in the context of the total number of bioabsorbable anchors placed. In 2008, 10 bioabsorbable anchor-related complications were reported to the US Food and Drug Administration. The reported literature complications of bioabsorbable anchors implanted about the shoulder include glenoid osteolysis, synovitis, and chondrolysis. These potential complications should be kept in mind when forming a differential diagnosis in a patient in whom a bioabsorbable anchor has been previously used. These literature reports, which amount to but a fraction of the total bioabsorbable anchors implanted in the shoulder on a yearly basis, underscore the relative safety and successful clinical results with use of bioabsorbable suture anchors. Product development continues with newer composites such as PEEK (polyetheretherketone) and calcium ceramics (tricalcium phosphate) in an effort to hypothetically create a mechanically stable construct with and improve biocompatibility of the implant. Bioabsorbable anchors remain a safe, reproducible, and consistent implant to secure soft tissue to bone in and about the shoulder. Meticulous insertion technique must be followed in using bioabsorbable anchors and may obviate many of the reported complications found in the literature. The purpose of this review is to provide an overview of the existing literature as it relates to the rare complications seen with use of bioabsorbable suture anchors in the shoulder.