Glenoid rim fracture in contact athletes with absorbable suture anchor reconstruction

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.

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.

Comparison between all-suture and biocomposite anchors in the arthroscopic treatment of traumatic anterior shoulder instability: A retrospective cohort study

Purpose

Suture anchors have revolutionized arthroscopic surgery, enabling direct soft tissue-to-bone repair. There are many types of anchors still used in arthroscopic shoulder operations. We sought to compare the clinical outcome of all-suture and biocomposite anchors when used in arthroscopic Bankart repair for patients suffering from anterior shoulder instability.

Methods

A single-center retrospective cohort study of 30 patients (mean age: 26.6 years, SD: 8.8 years, male/female ratio: 5/1, mean follow up: 28 months, SD: 23.8, range: 12-92) with anterior shoulder instability was conducted. Patients were divided into 2 groups based upon the type of suture anchors used for the Bankart repair: group A (14 patients) used only all-suture anchors and group B (16 patients) used only biocomposite anchors. Outcomes reported were postoperative dislocations, positive shoulder apprehension test, self-reported sense of shoulder instability, return to activities of daily living, return to sports, patient satisfaction and complications. Patient reported outcome measures (PROMs) used were the Rowe Score for Instability, Constant Shoulder Score, Walch Duplay Score, The American Shoulder and Elbow Surgeons (ASES) Shoulder Score, Oxford Shoulder Instability Score and external rotation at 90° of arm abduction, external rotation at 0° of arm abduction, forward flexion, abduction, adduction and internal rotation.

Results

Rates of postoperative shoulder dislocation demonstrated no significant difference between the 2 groups (p > .05). Four postoperative dislocations happened, two in each group (14.3% and 12.5% for all suture only and biocomposite only groups, respectively), with three of them being traumatic. In addition, no significant differences were observed amongst groups regarding shoulder apprehension test (group A: 85.7% vs. group B: 93.8%), sense of shoulder instability (7.1% vs. 6.3%), return to activities of daily living (group A: 85.7% vs. group B: 93.8%), return to sports (group A: 85.7% vs. group B: 87.5%), patient satisfaction (moderate level: group A 21.4% vs. group B 12.5%), and PROMs.

Conclusion

The short-term failure rate and clinical/functional outcomes of arthroscopic Bankart repair using all-suture anchors is similar to the use of biocompatible anchors.

Level of evidence

Level III, retrospective cohort study.

A comparative study on use of two versus three double-loaded suture anchors in arthroscopic Bankart repair

Objectives

This study aims to compare clinical results of repair using two versus three double-loaded suture anchors in arthroscopic Bankart repair.

Patients and methods

Between July 2012 and December 2017, a total of 40 patients (38 males, 2 females; mean age: 31.6±8.1; range: 17 to 47 years) who underwent Bankart arthroscopic surgery and were followed for minimum two years were retrospectively analyzed. Group 1 (n=17) underwent arthroscopic Bankart repair with two double-loaded suture anchors, while Group 2 (n=23) underwent repair with three double-loaded suture anchors. Clinical outcomes of the patients and recurrences were compared.

Results

At the final postoperative follow-up, a significant improvement was observed in the functional outcomes in all patients. No statistically significant difference was found (p>0.05) in the mean clinical scores of the Constant Shoulder Score between Group 1 (94.2±7.8) and Group 2 (95.4±4.1). There was no significant difference in the mean Rowe scores (Group 1: 95.6±4.6 vs. Group 2: 96.3±3.8, respectively) and external rotation loss (at neutral Group 1: 1.9o vs. Group 2: 2.2o, respectively). Three of our patients had recurrent dislocation during a major traumatic event (n=2 in Group 1 and n=1 in Group 2).

Conclusion

Our study results suggest that stability is not correlated with the use of either two versus three double-loaded suture anchors in arthroscopic Bankart repairs.

In Vivo Randomized Controlled Study of the Bone Response of All-Suture Anchors and Biocomposite Anchors

Background:

Suture anchors are widely used for labral reconstruction surgery. However, there has been some concern over the development of osteolysis around the anchor. This has been reported for both biocomposite and all-suture anchors, but they have not been compared directly in vivo.

Purpose:

To compare the bone response to 2 common suture anchors: a traditional biocomposite push-fit anchor and an all-suture anchor.

Study Design:

Randomized controlled trial; Level of evidence, 2.

Methods:

Included in this study were 17 patients with a total of 37 unique suture anchors. Magnetic resonance imaging scans were performed at 3 weeks and 6 months postoperatively. A total of 38 senior radiologists and shoulder surgeons evaluated the images using a previously validated system for grading the bone response around suture anchors. The mean difference in grading at 3 weeks and 6 months was calculated using unpaired t tests, and the interrater reliability was evaluated with an intraclass correlation coefficient (ICC).

Results:

At 3 weeks, there was no statistically significant difference in the degree of osteolysis surrounding each suture anchor type (P = .258), with little bone response. However, on the 6-month scans, there was a significantly lower level of osteolysis seen in the all-suture anchors compared with the biocomposite anchors (P = .040). Interrater reliability was excellent, with an ICC value of 0.975 (95% CI, 0.962-0.985).

Conclusion:

All-suture anchors cause significantly less osteolysis in glenoid bone at 6 months compared with biocomposite anchors.

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.

Editorial Commentary: Fill It up: The Fate of "Absorbable" Implants

Surgeons make conscious decisions daily regarding implants. But do they really know what happens in the body to "absorbable anchors?" How long does it take to resorb, and what fills the space left behind? Absorbable materials can be very different, and well-done studies are important to help us understand the process and to guide our decisions.

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.

Cytotoxicity and biomechanics of suture anchors used in labral repairs

Background

Biodegradable suture anchors are associated with higher redislocation rates. This study examined whether the biocompatibility and/or biomechanical properties of suture anchors contribute to the increase in complications.

Methods

Human glenohumeral capsule cells were cultured with 4 types of suture anchors, Opus LabraFix (titanium alloy; ArthroCare, Austin, TX, USA), PushLock (poly-ether-ether-ketone; Arthrex, Naples, FL, USA), BioKnotless (poly-l-lactic acid; DePuy Mitek, Warsaw, IN, USA), and Suretac II (polyglycolic acid; Smith & Nephew, London, UK), to measure cell viability and pH. Four groups of 6 ovine shoulders were used to repair the labrum, which was completely detached from the glenoid rim anteroinferiorly and reattached with 2 suture anchors and subject to failure load testing.

Results

In cell culture, BioKnotless at 48 and 72 hours (85.2% ± 2.1% and 84.5% ± 3.6%) and Suretac II groups (33.9% ± 3.1% and 42.8% ± 6.4%) had fewer viable cells compared with control (P = .048). The pH of Suretac II was lower than control (7.51 to 7.65) at 24 hours (7.31 ± 0.08, P = .049), 48 hours (7.25 ± 0.02, P = .046), and 72 hours (7.29 ± 0.04, P = .04). During mechanical testing, 83% of repairs failed by the capsule tearing. Among the anchors, the BioKnotless repair group had a significantly lower failure load (37 ± 5 N) compared with the PushLock (61 ± 7 N), Opus (60 ± 6 N), and Suretac II (57 ± 7 N) groups (P = .038).

Conclusion

BioKnotless and Suretac II anchors are cytotoxic. The BioKnotless biodegradable anchor has significantly lower failure load. Absorbable suture anchors may cause higher redislocation of arthroscopic Bankart repair.

Analysis of glenoid inter-anchor distance with an all-suture anchor system

Background

All-suture anchors used in arthroscopic shoulder stabilization employ small diameter anchors, which allow greater placement density on narrow surfaces such as the glenoid. There is no consensus in the literature about how close to one another two anchors may be implanted.

Purpose

The purpose of the present study is to compare the strength characteristics of two all-suture anchors placed in cadaveric human glenoid at variable distances to one another, in order to determine the minimum distance required for optimal strength.

Methods

Twelve fresh-frozen human cadaveric glenoids were implanted with 1.4 mm all-suture anchors at varying inter-anchor distances. Each glenoid was used for four tests, for a total of 48 tests. Anchors were implanted adjacent to one another or with 2, 3, or 5 mm bone bridges between pilot holes. The glenoids then underwent pullout testing using a test frame with a 5N preload followed by displacement of 12.5 mm/s. The primary outcomes were stiffness, failure strength, and ultimate strength.

Results

Stiffness was 13.52 ± 3.8, 17.97 ± 5.02, 17.59 ± 4.65 and 18.95 ± 4.67 N/mm for the adjacent, 2, 3, and 5 mm treatment groups, respectively. The adjacent group had a significantly lower stiffness compared to the other treatment groups. Failure strength was 48.68 ± 20.64, 76.16 ± 23.78, 73.19 ± 35.83 and 87.04 ± 34.67 N for the adjacent, 2, 3, and 5 mm treatment groups, respectively. The adjacent group had a significantly lower failure strength compared to the other treatment groups. Ultimate strength was also measured to be 190.59 ± 140.93, 268.7 ± 115.1, 283.23 ± 118.43, and 291.28 ± 118.24 for the adjacent, 2, 3, and 5 mm treatment groups, respectively.

Conclusions

This biomechanical study provides evidence that 1.4 mm all-suture anchors demonstrate similar strength characteristics when placed at least 2 mm or greater from one another. When 1.4 mm all-suture anchors were placed adjacent to one another, there was an observed decrease in failure strength and stiffness.

Clinical relevance

This study suggests that 1.4 mm all-suture anchors may be placed as close as 2 mm to one another while preserving strength characteristics.

Arthroscopic Soft Tissue Procedures for Anterior Shoulder Instability

Background:

Arthroscopy has rapidly transformed the treatment of anterior shoulder instability over the past 30 years. Development of arthroscopic equipment has permitted the investigation and diagnosis of the unstable shoulder, and fixation methods have evolved to promote arthroscopy from an experimental procedure to one of first-line mainstream treatment.

Methods:

Key research papers were reviewed to identify the fundamental principles in patient diagnosis and appropriate selection for arthroscopic treatment. The evolution of arthroscopy is described in this article to facilitate the understanding of current treatment.

Results:

Accurate diagnosis of the shoulder instability subtype is essential prior to selection for surgery. Different surgical techniques are described to address different pathology within the glenohumeral joint related to instability and the appropriate method should be selected accordingly to optimise outcome.

Conclusion:

Anterior shoulder instability can be treated successfully using arthroscopic surgery, but the surgeon must treat each patient as an individual case and recognise the different subtypes of instability, the associated pathological lesions and the limitations of arthroscopy. The article concludes with a suggested algorithm for the treatment of anterior shoulder instability.

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.

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.

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.

Postoperative imaging of bioabsorbable anchors in rotator cuff repair

BACKGROUND

Bioabsorbable anchors may lead to osteolysis and cyst formation. However, the prevalence of these outcomes is not known for rotator cuff repairs.

PURPOSE

To evaluate cyst formation after placement of bioabsorbable anchors for rotator cuff repairs and to verify whether bioabsorbable anchors degraded as intended and preserved bone stock for possible revision compared with metal anchors. The null hypothesis was that the rate and severity of cyst formation around the anchor are negligible.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between April 2008 and November 2011, a total of 209 patients (85 men, 124 women) underwent rotator cuff repair with bioabsorbable suture anchors (113 with polylactic acid enantiomers [PLLA] and 96 with poly-D,L-lactide from L-lactide and D-lactide [PLDLA]); the patients underwent magnetic resonance imaging (MRI) evaluation more than 10 months after surgery. The fluid signal around the anchor on T2-weighted MRI scans was graded as follows: grade 0, no fluid around anchor; grade 1, minimal fluid around anchor; grade 2, local fluid around anchor; grade 3, fluid collection around entire length of anchor with cyst diameter less than twice the anchor diameter; and grade 4, cyst diameter larger than grade 3. The integrity of repairs was also evaluated.

RESULTS

Cysts were observed in 97 instances (46.4%). There were 41 grade 1 cases (19.6%), 16 grade 2 (7.7%), 22 grade 3 (10.5%), and 18 grade 4 (8.6%). Healing of repaired tendon was observed in 131 patients (62.7%). There was no statistical difference in healing rate between patients with and without cyst formation (66.1% vs 58.8%; P = .276). Altered anchor shape and absorption were not observed in most of the patients. However, in 12 patients (6 with PLLA and 6 with PLDLA anchors), T2-weighted scans showed that the signal intensity of anchors had changed since surgery, which could indicate that absorption had taken place; nonetheless, even in these 12 patients, anchors were clearly visible on T1-weighted scans.

CONCLUSION

Osteolysis and cyst formation are common complications following the use of bioabsorbable anchors in rotator cuff repairs. Considering that adequate absorption of anchors and preservation of bone stock are the reasons for using bioabsorbable anchors, use of these anchors should be reconsidered because of possible interference with revision surgery.

Pullout strength of all suture anchors in the repair of rotator cuff tears: a biomechanical study

PURPOSE

We evaluated the biomechanical strength of two all suture anchors (ASA) of reduced diameter (1.4 mm) and compared them with the standard screw anchor (SA) with larger diameter (5.5 mm) used in rotator cuff tears.

METHODS

We conducted 30 uniaxial vertical pullout tests using Material Testing System Instron 5566A until failure of the anchorage defined as rupture of the threads or anchor or detachment of the anchor. Anchor fixation was on tuberosities of fresh bovine humerus bone. ASAs were spaced four millimetres apart and were compared with a control SA implanted on the same greater tubercle at two centimetres. The tests were all performed at room temperature in a dry environment. Tensile loads (10 mm/min) were applied parallel to the axis of insertion. A preloading of 10 N was used to overcome loading artifacts of the test sample at the beginning of the test.

RESULTS

Student's t test showed no statistically significant difference between anchors in terms of load to failure (ASA: force 265.06 ± 87.25 N versus SA : 325.35 ± 113.46 N; p = 0.09) and mean elongation at rupture (ASA : 23 ± 7 mm versus SA : 21 ± 6 mm; p = 0.46).

CONCLUSIONS

In vitro, this experimental study showed no statistically significant difference in pullout strength and displacement between ASA and SA at a chosen level of significance (p < 0.05).

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.

Biomechanical analysis of pullout strengths of rotator cuff and glenoid anchors: 2011 update

PURPOSE

To evaluate the biomechanical and design characteristics of newer suture anchors.

METHODS

Suture anchors were tested in fresh porcine metaphyseal cortex and cancellous troughs by use of an established protocol. A mechanical testing machine applied tensile loads parallel to the axis of insertion at 12.5 mm/s until failure, and mean anchor failure strengths were calculated. The mode of failure was recorded. Rotator cuff anchors tested included the Doubleplay and Opus SpeedScrew (ArthroCare Sports Medicine, Sunnyvale, CA); PEEK Intraline and PEEK Zip (Stryker, San Jose, CA); Paladin, SuperRevo FT, and CrossFT (ConMed Linvatec, Largo, FL); Piton (Tornier, Warsaw, IN); Ti Screw, ALLthread PEEK, LactoScrew, ALLthread Ti, and ALLthread PEEK knotless (Biomet Sports Medicine, Warsaw, IN). Glenoid anchors included the Gryphon BR P (DePuy-Mitek, Raynham, MA) and JuggerKnot 1.4 (Biomet Sports Medicine).

RESULTS

Mean cortical failure loads for cuff anchors were as follows: Doubleplay 5.0, 279 N; Doubleplay 6.5, 338 N; Opus SpeedScrew 5.5, 356 N; Opus SpeedScrew 6.5, 336 N; PEEK Intraline 5.5, 263 N; PEEK Intraline 6.5, 344 N; PEEK Zip 5.5, 435 N; PEEK Zip 6.5, 502 N; Paladin 5.0, 500 N; Paladin 6.5, 521 N; SuperRevo FT, 496 N; CrossFT, 569 N; Piton, 379 N; Ti Screw 5.0, 457 N; Ti Screw 6.5, 443 N; ALLthread PEEK 5.5, 476 N; LactoScrew 5.5, 403 N; ALLthread Ti 5.0, 526 N; ALLthread Ti 6.5, 653 N; and ALLthread PEEK knotless, 441 N). Mean cortical failure loads for glenoid anchors were 161 N for Gryphon BR P and 239 N for JuggerKnot 1.4. Mean cancellous bone failure loads for cuff anchors were Doubleplay 5.0, 263 N; Doubleplay 6.5, 340 N; Opus SpeedScrew 5.5, 356 N; Opus SpeedScrew 6.5, 344 N; PEEK Intraline 5.5, 274 N; PEEK Intraline 6.5, 327 N; PEEK Zip 5.5, 401 N; PEEK Zip 6.5, 396 N; Paladin 5.0, 427 N; Paladin 6.5, 491 N; SuperRevo FT, 483 N; CrossFT, 547 N; Piton, 365 N; Ti Screw 5.0, 420 N; Ti Screw 6.5, 448 N; ALLthread PEEK 5.5, 475 N; LactoScrew 5.5, 435 N; ALLthread Ti 5.0, 512 N; ALLthread Ti 6.5, 612 N; and ALLthread PEEK knotless, 466 N). Mean cancellous failure loads for glenoid anchors were 117 N for Gryphon BR P and 194 N for JuggerKnot 1.4. None of the anchors had pullout as the predominant failure mode. Eyelet failure was the predominant failure mode for Doubleplay, Opus SpeedScrew, PEEK Intraline, Gryphon BR P, ALLthread Ti 6.5, ALLthread PEEK 5.5, and LactoScrew.

CONCLUSIONS

Failure load was not dependent on anchor location (cancellous or cortical bone) (P = .58) but was dependent on anchor type (cuff anchor or glenoid anchor) (P < .001).

CLINICAL RELEVANCE

Whereas larger fully threaded screw anchors designed for rotator cuff repair showed higher failure strengths than smaller non-screw anchors designed for glenoid repairs (P < .05), the larger version of a screw anchor for a cuff repair did not provide a statistically greater failure load than the smaller screw anchor.

Recurrent anterior shoulder instability associated with bony defects

Mobility of the glenohumeral joint is facilitated through the complex interplay of soft tissue and osseous anatomy. Arthroscopic shoulder stabilization is commonly used in the surgical management of shoulder instability. However, the management of the unstable shoulder associated with bony defects (glenoid, humeral, or combined) can be challenging. Adequate recognition of bony defects is paramount to successful treatment and entails a careful history, clinical examination, and advanced radiographic imaging. Nonoperative methods of treatment are often insufficient for treating patients with large bony defects. Bony procedures, as opposed to soft procedures, may yield better outcomes in this patient population. However, respective surgical techniques used to address these defects are technically challenging with a significant learning curve and may lead to significant morbidity. This represents a paradigm shift in treatment and replaces the old paradigm of "open vs arthroscopic" instability surgery.

Comparison between metal and biodegradable suture anchors in the arthroscopic treatment of traumatic anterior shoulder instability: a prospective randomized study

PURPOSE

The purpose of this study was to compare the clinical outcome of arthroscopic treatment of shoulder instability with metal and biodegradable suture anchors.

METHODS

Arthroscopic stabilization was performed in 78 patients with recurrent traumatic anterior shoulder instability. They were divided into 2 groups of 39 patients each, according to suture anchors used: metal anchors in group 1, and biodegradable anchors in group 2. Results were evaluated by use of the Disabilities of the Arm, Shoulder and Hand (DASH) self-administered questionnaire; Rowe score; Constant score normalized for age and gender, and recurrence of dislocation.

RESULTS

On analyzing the results at a 2-year follow-up, we considered the following independent variables: age; gender; arm dominance; duration of symptoms, age at first dislocation, number of dislocations, type of work; type of sport; sports activity level; lesion of the anterior labrum and anterior-inferior gleno-humeral ligament; SLAP lesion, and number of suture anchors. Comparison between groups did not show significant differences for each variable considered. Overall, according to the results, median DASH scores were 4.5 points (range 0-27) in group 1 and 7 points (range 0-25) in group 2 (n.s.); median Rowe scores were 100 points (range 60-100) and 100 points (range 25-100), respectively (n.s.); and median Constant scores were 98 points (range 81-107) and 98 points (range 87-121), respectively (n.s.). Recurrence was observed in 1 patient (2.8%) in group 1 and in 2 patients (5.9%) in group 2. Overall recurrence rate was 4.3%. Univariate and multivariate analysis showed that age, duration of symptoms, number of dislocations, type of work, and type of sports significantly and independently influenced the outcomes. Differences between groups 1 and 2 were not significant.

CONCLUSION

At a short-term follow-up, differences between arthroscopic shoulder stabilization with metal and biodegradable suture anchors were not statistically significant. Clinical relevance of the study is that there is no difference in the use of metal or biodegradable suture anchors for the arthroscopic treatment of shoulder instability.