Complications of bioabsorbable suture anchors in the shoulder

Magnetic resonance imaging for relationship between the severity of perianchor fluid collection and rotator cuff integrity after arthroscopic double-row suture-bridge rotator cuff repair

PURPOSE

The primary purpose of this study was to assess perianchor fluid collection (PFC) severity of medial anchor and rotator cuff integrity association after arthroscopic double-row suture-bridge rotator cuff repair (RCR) and the secondary purpose was to identify the demographic and radiologic risk factors for high-grade PFC.

HYPOTHESIS

Re-tear rate would be significant higher in patients with high-grade PFC.

METHODS

We retrospectively reviewed patients with arthroscopic double-row suture-bridge RCR for full-thickness rotator cuff tear (RCT) at our institution between February 2012 and May 2018. Based on the PFC severity, they were divided into the no-fluid (no fluid collection), low-grade (minimal or local fluid collection around the anchor), and high-grade (fluid collection beyond the entire length of the anchor) groups. Magnetic resonance imaging was performed 6 months postoperatively for assessing PFC severity and repaired rotator cuff integrity association, besides evaluating correlation between severity and various demographic and radiologic factors, including work level (low/medium/high) and RCT size.

RESULTS

This study included 312 patients, 181 (58%) in the no fluid group, 82 (26.3%) in the low-grade PFC group, and 49 (15.7%) in the high-grade PFC group. Re-tear occurred in 73 (23.4%) patients and was more frequent in the high-grade group (26/49 [53.1%]) than in the no-fluid (27/181 [14.9%]; p<0.001) and low-grade (20/82 [24.4%]; p=0.001) groups, without statistically significant differences between the latter two (p=0.082). Among the demographic factors, work level (low/medium/high) differed significantly between the no-fluid (22.1%/58.0%/19.9%), low-grade (25.7%/46.3%/28.0%), and high-grade (26.5%/34.7%/38.8%) groups (p=0.026). Among the radiologic factors, the mediolateral tear size differed significantly between the three groups (no-fluid group: 1.7±0.8cm, low-grade group: 1.8±0.6cm, high-grade group: 2.2±1.0cm; p=0.003). Multivariate regression analysis showed that mediolateral tear size (odds ratio: 1.821; 95% confidence interval: 1.258-2.636; p=0.001) was an independent risk factor for high-grade PFC.

CONCLUSIONS

After arthroscopic double-row suture-bridge RCR, the highest re-tear rate was observed in patients with high-grade PFC, while there was no significant difference in rates between no-fluid and low-grade PFC groups. As PFC severity increased, the risk of re-tear increased. In particular, larger mediolateral tear size was associated with high-grade PFC.

LEVEL OF EVIDENCE

III; case-control study.

Clinical Outcome of an All Arthroscopic 'Whole Layer' Rotator Cuff Repair Technique with Simultaneous Biceps Tenodesis

OBJECTIVE

To retrospectively evaluate clinical outcomes, including function and pain, of patients after our all arthroscopic "whole layer" rotator cuff repair technique with simultaneous biceps tenodesis procedure; factors influencing results were also evaluated. Given the frequent association of rotator cuff tear with long head of biceps lesion and the need for effective combined treatment strategies, this study aims to evaluate the efficacy of our technique and compare it with established methods. We hypothesized that our technique would significantly improve function and reduce pain in patients with rotator cuff tears and biceps pathology.

METHODS

This is a retrospective study that included patients older than 20 years who underwent all arthroscopic "whole layer" rotator cuff repair technique with simultaneous biceps tenodesis procedures for concomitant rotator cuff tear and long head biceps pathology, from 2016 to 2020. Patients were evaluated preoperatively and at a minimum of 2 years of follow-up using the American Shoulder and Elbow Surgeons (ASES) and visual analogue scale (VAS) scores paired t-tests were used for analysis and statistical significance was set at p < 0.05(two-tailed). The satisfaction rate and complications were also evaluated.

RESULTS

After an average follow-up of 2.3 years, 118 patients demonstrated significant improvement in both the ASES score (from 36.13 to 95.01, p < 0.001) and VAS score (from 6.81 to 0.89, p < 0.001). Ninety-four percent of the patients reported satisfaction with the surgical outcome. No complications related to Popeye deformity, biceps cramping pain, or ipsilateral shoulder reoperation were observed. Factors such as age, sex, body mass index (BMI), smoking status, alcohol consumption, hypertension, and diabetes did not influence the results. Patients showed significant improvement in both the ASES and VAS scores (p < 0.001).

CONCLUSION

At a mean follow-up time of 2.3 years, the all arthroscopic "whole layer" rotator cuff repair technique with simultaneous biceps tenodesis is a therapeutic and efficient procedure. The procedure revealed a satisfactory functional outcome, reduced pain, and minimal complications and reoperations.

The Relationship Between All-Suture and Solid Medial-Row Anchors and Patient-Reported Outcomes for Double-Row Suture Bridge Rotator Cuff Repair

Background

The use of all-suture anchors for rotator cuff repair is increasing. Potential benefits include decreased bone loss and decreased damage to the chondral surface. Minimal evidence exists comparing outcomes among medial-row anchor fixation methods in double-row suture bridge rotator cuff repair.

Purpose

To compare the clinical outcomes between all-suture and solid medial-row anchors in double-row suture bridge rotator cuff repair.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 352 patients (mean age at surgery, 60.3 years) underwent double-row suture bridge rotator cuff repair at our institution. Patients were separated into 2 groups based on whether they underwent all-suture (n = 280) or solid (n = 72) anchor fixation for the medial row. Outcomes data were collected via an ongoing longitudinal data repository or through telephone calls (minimum follow-up time, 2.0 years; mean follow-up time, 3.0 years). Outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) standardized shoulder assessment form and the visual analog scale (VAS). The same rehabilitation protocol was administered to all patients. The proportions of patients meeting previously published Patient Acceptable Symptom State (PASS) thresholds were calculated for the outcome measures, and outcome scores and the proportions of patients meeting PASS thresholds between groups were compared using linear and logistic regression, respectively.

Results

The groups did not differ in terms of age at surgery, sex distribution, rotator cuff tear size, or number of medial-row anchors used. The solid anchor group had a longer follow-up time compared with the all-suture anchor group (3.6 ± 0.7 vs 2.8 ± 0.8 years, respectively; P < .01). After controlling for follow-up time, the solid and all-suture anchor groups did not differ in ASES scores (89.6 ± 17.8 vs 88.8 ± 16.7, respectively; P = .44) or VAS scores (1.1 ± 2.1 vs 1.2 ± 2.1, respectively; P = .37). Similarly, after controlling for follow-up time, the solid and all-suture anchor groups did not differ in the proportions of patients meeting PASS cutoffs for the ASES (84.7% vs 80.7%, respectively; P = .44) or the VAS (80.6% vs 75.0%, respectively; P = .83).

Conclusion

Double-row suture bridge rotator cuff repair using all-suture anchors for medial-row fixation demonstrated similar excellent clinical outcomes to rotator cuff repair using solid medial-row anchors.

Biocomposite Anchors Have Greater Yield Load and Energy Compared With All-Suture Anchors in an In Vitro Ovine Infraspinatus Tendon Repair Model

Purpose

To compare tensile fatigue and strength measures of biocomposite and all-suture anchors in an ovine humerus-infraspinatus tendon model of rotator cuff repair.

Methods

Infraspinatus tendons on adult ovine humeri were sharply transected at the insertion. One of each pair was assigned randomly for fixation with 2 biocomposite or all-suture anchors. Constructs were tested with 200 cycles of 20 to 70 N tensile load, and gap formation was measured at the incised tendon end every 50 cycles. They were subsequently tested to failure. Outcome measures including fatigue stiffness, hysteresis, creep, and gap formation and tensile stiffness, and yield and failure displacement, load, and energy were compared between anchors.

Results

Biocomposite anchors had greater yield load (134.1 ± 6.5 N, P < .01) and energy (228.6 ± 85.7 J, P < .03) than all-suture anchors (104.7 ± 6.5 N, 169.8 ± 85.7 J). Fatigue properties were not different between anchors, but stiffness and gap formation increased and hysteresis and creep decreased significantly with increasing cycle number.

Conclusions

Although the yield displacement of both anchors was within the range of clinical failure, the tensile yield load and energy of ovine infraspinatus tendons secured to the humerus with 2 single-loaded all-suture anchors in a single row were significantly lower than those secured with 2 biocomposite anchors in the same configuration.

Clinical Relevance

It is important to understand the biomechanical properties for selecting anchors for rotator cuff repair. A direct comparison of fatigue testing followed by failure strength of infraspinatus tendon fixation with all-suture and biocomposite anchors could help guide anchor selection and postoperative mobility recommendations.

Fixation strength of swelling copolymeric anchors in artificial bone

Fixation with suture anchors and metallic hardware for osteosynthesis is common in orthopedic surgeries. Most metallic commercial bone anchors achieve their fixation to bone through shear of the bone located between the threads. They have several deficiencies, including stress-shielding due to mechanical properties mismatch, generation of acidic by-products, poor osteointegration, low mechanical strength and catastrophic failure often associated with large bone defects that may be difficult to repair. To overcome these deficiencies, a swelling porous copolymeric material, to be used as bone anchors with osteointegration potential, was introduced. The purpose of this study was to investigate the fixation strength of these porous, swelling copolymeric bone anchors in artificial bone of various densities. The pull-out and subsidence studies indicate an effective fixation mechanism based on friction including re-fixation capabilities, and minimization of damage following complete failure. The study suggests that this swelling porous structure may provide an effective alternative to conventional bone anchors, particularly in low-density bone.

Clinical and radiological outcome after arthroscopic rotator cuff repair using PEEK-CF anchors

PURPOSE

The goal of this study was to evaluate the clinical and radiological outcome after arthroscopic rotator cuff repair using new carbonfiber reinforced polyetheretherketone (CF-PEEK) suture anchors.

METHODS

One hundred (n=100) patients with rotator cuff tears were enrolled at seven French hospitals between July 2019 and June 2020. Pain levels, Constant score and Subjective Shoulder Value (SSV) were taken preoperatively and 6months postoperatively. Ultrasonography (US) was performed at 6months postoperatively to evaluate tendon healing using the Sugaya classification. Statistical analysis was done with the Student t-test with 95% confidence intervals.

RESULTS

One hundred patients of the 100 patients were followed at 6months. The mean SSV and Constant score improved from 40.1% preoperatively to 78% at 6months (p<0.0001) and from 43 points preoperatively to 65 points at 6months (p<0.0001), respectively. The mean level of pain, as measured with the visual analogue scale, decreased from 5.9 to 1.6 (p<0.001). There were no postoperative complications that resulted in revision surgery.

CONCLUSION

The study showed good results at 6months follow-up using carbonfiber reinforced PEEK anchors with improved Constant and SSV scores as well as a high ultrasonographic tendon healing rate, making PEEK-CF anchors safe to use, comparable to commonly used anchors.

LEVEL OF EVIDENCE

IV.

Tommy John Ligament Repair with Ulnar Collateral Ligament Internal Brace

Ulnar collateral ligament (UCL) injuries commonly occur in overhead athletes as a result of excess valgus stress on the elbow and can be functionally debilitating, requiring surgical intervention. Since the advent of the first initial UCL reconstruction technique pioneered by Dr. Frank Jobe performed on professional baseball player Tommy John, UCL, or Tommy John Ligament reconstruction has successfully returned athletes to sport following injury and shown enhanced clinical outcomes with minimal complication rates. Tommy John surgery continues to evolve with the development of various techniques over recent years. This technical note describes a UCL repair with an internal brace using knotless suture anchors and aims to contribute to the current literature a technique that is efficacious and reproducible and offers satisfactory stability, functionality, and return to play.

Metal vs non-metal fixation methods for patellar fractures: A systematic review and meta-analysis of clinical and radiographic outcomes

Introduction

This paper aims to systematically review and meta-analyse the available evidence regarding the clinical and radiographic outcomes of non-metal fixation methods in treating patellar fractures compared to a control metal fixation group, in the hopes of bringing insight into their effectiveness.

Methods

Two investigators systematically reviewed studies across 9 English or Mandarin electronic databases - Cochrane Library, EMBASE, Google Scholar, Medline, PubMed, Scopus, Web of Science, CNKI and Wanfang Data, in adherence to PRISMA guidelines. The inclusion criteria for study selection were: English or Mandarin comparative studies that evaluated clinical (Patient Reported Outcome Measures, incidence of reoperations and postoperative complications) or radiographic (time to union and incidence of secondary loss of reduction) outcomes of metal and non-metal fixation methods for patellar fractures. From an initial pool of 1269 studies, 19 studies involving 1612 patients were included in the meta-analysis after full-text evaluation and accounting for exclusion criteria.

Results

Clinically, the reduction in reoperations (OR = 0.22, 95% CI [0.10, 0.51], P = 0.0003), direct (OR = 0.17, 95% CI [0.08, 0.33], P < 0.00001) and indirect (OR = 0.50, 95% CI [0.27, 0.93], P = 0.03) implant-related postoperative complications were significantly in favor of non-metal fixation. Radiographically, the decrease in time to union (SMD = -0.79, 95% CI [-1.11, -0.47], P < 0.00001) in the non-metal group compared to the metal group was also significant. The remaining results were comparable.

Conclusion

This meta-analysis suggests that non-metallic internal fixation had similar if not superior outcomes to their metallic counterparts, with fewer implant-related complications and improved postoperative recovery. Given the higher re-operation rates associated with metallic fixation, non-metallic methods may be preferable from economic and safety perspectives. Nevertheless, more homogenous studies with standardised fracture configurations and treatment modalities are needed before declaring non-metallic fixation as the gold standard for patellar fractures.

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.

Osteolysis Following the Use of Polyetheretherketone Suture Anchors in Hand and Wrist Surgery: A Preliminary Study

PURPOSE

The objective of this study was to investigate and describe the presence of osteolysis after implantation of polyetheretherketone (PEEK) suture anchors in the hand and wrist.

METHODS

Patients who underwent hand or wrist surgery using PEEK suture anchor(s) at a large academic institution from January 2019 to January 2021 were identified. Patients without accessible intraoperative fluoroscopic imaging were excluded. Patient demographics, type of procedure, and suture anchor material were recorded. The suture anchor tunnel size was measured on sequential radiographs and recorded as percentage change. Descriptive statistics were used to summarize findings.

RESULTS

A total of 26 PEEK suture anchors in 14 patients were included, with an average follow-up of 12.0 months (range, 1.5-24.1 months). Twenty-seven percent of the anchors (7/26) demonstrated osteolysis at final follow-up, as defined by enlargement of tunnel size by >30%. In all anchors, the tunnel size increased by 19.1% on average (range, -7.7% to 56.1%) by final follow-up.

CONCLUSIONS

Polyetheretherketone suture anchors may be associated with the development of osteolysis in hand and wrist surgery. The clinical implications of osteolysis in the smaller bones of the hand and wrist remain unclear.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Outcomes of Double-Row Rotator Cuff Repair Using a Novel All-Suture Soft Anchor Medial Row

Background

Few studies have examined the short-term clinical outcomes of rotator cuff repair (RCR) with all-suture anchors for medial row anchor fixation.

Purpose

To evaluate clinical outcomes of double-row suture bridge RCR using a novel all-suture medial row anchor.

Study Design

Case series; Level of evidence, 4.

Methods

We enrolled 179 patients before double-row suture bridge RCR (mean age at surgery, 60.0 years; 63% male patients) at a single institution. All patients underwent RCR with all-suture anchor fixation for the medial row and solid anchor fixation for the lateral row. Preoperative (baseline) and follow-up (minimum follow-up time of 2 years; mean, 2.5 years) clinical outcomes were compared using the American Shoulder and Elbow Surgeons (ASES) score and a 10-point numeric pain rating scale (NPRS). We calculated the proportions of patients meeting previously published Patient Acceptable Symptom State (PASS) thresholds for the ASES (≥78.0) and NPRS (≤1.7). We further compared baseline and follow-up outcome scores and the proportions of patients meeting PASS thresholds using paired t tests and McNemar tests, respectively, and calculated effect size to quantify the magnitude of change from baseline to follow-up.

Results

Values significantly improved from baseline to follow-up for ASES (from 45.3 ± 19.8 to 87.3 ± 17.1) and NPRS (from 5.2 ± 2.5 to 1.4 ± 2.1). The proportion of patients meeting PASS thresholds also significantly improved for the ASES (from 6% to 77%) and the NPRS (from 7% to 72%). The magnitude of baseline to follow-up change for all measures was large (all effect sizes ≥1.5).

Conclusion

Our study demonstrated excellent short-term clinical outcomes and substantial improvements for patients undergoing double-row suture bridge RCR with all-suture anchors for medial row fixation.

Numerical analysis of the mechanical response of novel swelling bone implants in polyurethane foams

In this study, a numerical framework was developed in order to analyze the swelling properties, mechanical response and fixation strength of swelling bone anchors. Using this framework, fully porous and solid implants, along with a novel hybrid design (consisting of a solid core and a porous sleeve), were modeled and studied. Free swelling experiments were conducted to investigate their swelling characteristics. The finite element model of swelling was validated using the conducted free swelling. Compared with the experimental data, results obtained from the finite element analysis proved the reliability of this frame-work. Afterwards, the swelling bone anchors were studied embedded in artificial bones with different densities with two different interface properties: considering frictional interface between the bone anchors and artificial bones (simulating the stages prior to osteointegration, when the bone and implant are not fully bonded and the surface of the implant can slide along the interface), and perfectly bonded (simulating the stages subsequent to osteointegration, when the bone and implant are fully bonded). It was observed that the swelling considerably decreases while the average radial stress on the lateral surface of the swelling bone anchor surges in the denser artificial bones. Ultimately, the pull-out experiments and simulations of the swelling bone anchors from the artificial bones were conducted to look into the fixation strength of the swelling bone anchors. It was found that the hybrid swelling bone anchor exhibits mechanical and swelling properties close to those of solid bone anchors, while also bone in-growth is expected to happen, which is an integral factor to these bone anchors.

Polyetheretherketone development in bone tissue engineering and orthopedic surgery

Polyetheretherketone (PEEK) has been widely used in the medical field as an implant material, especially in bone tissue engineering and orthopedic surgery, in recent years. This material exhibits superior stability at high temperatures and is biosecured without harmful reactions. However, the chemical and biological inertness of PEEK still limits its applications. Recently, many approaches have been applied to improve its performance, including the modulation of physical morphology, chemical composition and antimicrobial agents, which advanced the osteointegration as well as antibacterial properties of PEEK materials. Based on the evolution of PEEK biomedical devices, many studies on the use of PEEK implants in spine surgery, joint surgery and trauma repair have been performed in the past few years, in most of which PEEK implants show better outcomes than traditional metal implants. This paper summarizes recent studies on the modification and application of biomedical PEEK materials, which provides further research directions for PEEK implants.

Global Compressive Loading from an Ultra-Thin PEEK Button Augment Enhances Fibrocartilage Regeneration of Rotator Cuff Enthesis

A PEEK button is developed to improve the tendon-to-bone compression area. In total, 18 goats were divided into 12-week, 4-week, and 0-week groups. All underwent bilateral detachment of the infraspinatus tendon. In the 12-week group, 6 were fixed with a 0.8-1 mm-thick PEEK augment (A-12, Augmented), and 6 were fixed with the double-row technique (DR-12). Overall, 6 infraspinatus were fixed with PEEK augment (A-4) and without PEEK augment (DR-4) in the 4-week group. The same condition was performed in the 0-week groups (A-0 and DR-0). Mechanical testing, immunohistochemistry assessment, cell responses, tissue alternation, surgical impact, remodeling, and the expression of type I, II, and III collagen of the native tendon-to-bone insertion and new footprint areas were evaluated. The average maximum load in the A-12 group (393.75 (84.40) N) was significantly larger than in the TOE-12 group (229.17 (43.94) N) (p < 0.001). Cell responses and tissue alternations in the 4-week group were slight. The new footprint area of the A-4 group had better fibrocartilage maturation and more type III collagen expression than in DR-4 group. This result proved the novel device is safe and provides superior load-displacement to the double-row technique. There is a trend toward better fibrocartilage maturation and more collagen III secretions in the PEEK augmentation group.

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.

A highly elastic absorbable monofilament suture fabricated from poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

To address the growing demand for more elastic sutures free from unwanted knot loosening, we fabricated an absorbable monofilament suture from poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and subjected it to physical property characterization and performance evaluation (in vitro and in vivo degradability tests and a porcine abdominal wall suture test). As this flexible, highly stretchable, and difficult-to-untie suture exhibited additional advantages of small knot size and medium to long-term bioabsorbability, it was concluded to be a safe alternative to existing monofilament sutures, with far-reaching potential applications.

A porous swelling copolymeric material for improved implant fixation to bone

Most metallic commercial bone anchors, such as screws and suture anchors achieve their fixation to bone through shear of the bone located between the threads. They have several deficiencies, potentially leading to failure, which are particularly evident in low-density bone. These include stress-shielding resulting from mechanical properties mismatch; lack of mechanically induced remodeling and osteointegration; and when the pullout force on the anchor, during functional activities, exceeds their pullout strength, catastrophic failure occurs leaving behind large bone defects that may be hard to repair. To overcome these deficiencies, we introduced in this study a porous swelling co-polymeric material and studied its swelling and compressive mechanical characteristics as bone anchor under different configurations. Porosity was achieved by adding a non-dissolvable agent (NaCl) during the process of polymerization, which was later dissolved in water, leaving behind a porous structure with adequate porosity for osteointegration. Three different groups of cylindrical samples of the swelling co-polymer were investigated. Solid, fully porous, and partially porous with a solid core and a porous outer layer. The results of the swelling and simple compression study show that the partially porous swelling co-polymer maintains excellent mechanical properties matching those of cancellous bone, quick swelling response, and an adequate porous outer layer for mechanically induced osteointegration. These suggest that this material may present an effective alternative to conventional bone anchors particularly in low-density bone.

Cyst formation and bony ingrowth inside coil-type open-architecture anchors used for arthroscopic remplissage: a volumetric computed tomographic study of 50 anchors

BACKGROUND

The use of anchors in the proximal humerus during arthroscopic surgery can cause localized bone loss due to osteolysis and cyst formation. The purpose of this study was to use computed tomography (CT) to evaluate the incidence of implant-related bone loss and cyst formation after implantation of polyetheretherketone (PEEK) coil-type open-architecture anchors during remplissage for the management of Hill-Sachs defects (HSDs) in patients with shoulder instability.

METHODS

This was a single-cohort, observational study with a minimum of 12 months of follow-up. Subjects undergoing arthroscopic instability surgery with HSD requiring remplissage were included. The volume of the bone defects and the degree of bony ingrowth into the anchor were measured on CT images.

RESULTS

Thirty-one participants (28 males, 3 females; mean age 29.4 years, standard deviation [SD] 10.6) in whom 50 anchors (4.5-mm Healicoil PEEK double-loaded anchors) were used were evaluated with a CT performed at a mean of 14.1 (SD 3.74) months after surgery. Full bony ingrowth inside the anchor was found in 15 anchors (30%, range 17.8%-44.5%); clear ossification with a thin lucent rim was found in 10 anchors (20%, range 10.0%-33.7%); discontinuous ossification was found in 8 anchors (16%, range 7.2%-29.1%); and no ossification was observed inside 17 anchors (34%, range 21.2%-48.7%). Regarding bone defect size, no bone defect was identified in 15 anchors (30%, 95% CI 17.9%-44.6%), a partial bone defect was found in 17 anchors (34%, 95% CI 21.2%-48.7%), hole enlargement was found in 17 anchors (34%, 95% CI 21.2%-48.7%), and 1 anchor caused a cyst larger than twice the size of the hole made for anchor insertion (2%, 95% CI 0.1%-8.6%). At the 1-year evaluation, none of the participants presented recurrence or residual apprehension.

CONCLUSION

The use of PEEK coil-type open-architecture anchors for remplissage during instability surgery caused large cystic lesions in less than 10% of anchors. There was full bony ingrowth in one-third of anchors, and partial cancellous bone ingrowth occurred in another third of anchors.

Risk Factors and Corresponding Management for Suture Anchor Pullout during Arthroscopic Rotator Cuff Repair

INTRODUCTION

Due to the aging of the population, the incidence of rotator cuff tears is growing. For rotator cuff repair, arthroscopic suture-anchor repair has gradually replaced open transosseous repair, so suture anchors are now considered increasingly important in rotator cuff tear reconstruction. There are some but limited studies of suture anchor pullout after arthroscopic rotator cuff repair. However, there is no body of knowledge in this area, which makes it difficult for clinicians to predict the risk of anchor pullout comprehensively and manage it accordingly.

METHODS

The literature search included rotator cuff repair as well as anchor pullout strength. A review of the literature was performed including all articles published in PubMed until September 2021. Articles of all in vitro biomechanical and clinical trial levels in English were included. After assessing all abstracts (n = 275), the full text and the bibliographies of the relevant articles were analyzed for the questions posed (n = 80). Articles including outcomes without the area of interest were excluded (n = 22). The final literature research revealed 58 relevant articles. Narrative synthesis was undertaken to bring together the findings from studies included in this review.

RESULT

Based on the presented studies, the overall incidence of anchor pullout is not low, and the incidence of intraoperative anchor pullout is slightly higher than in the early postoperative period. The risk factors for anchor pullout are mainly related to bone quality, insertion depth, insertion angle, size of rotator cuff tear, preoperative corticosteroid injections, anchor design, the materials used to produce anchors, etc. In response to the above issues, we have introduced and evaluated management techniques. They include changing the implant site of anchors, cement augmentation for suture anchors, increasing the number of suture limbs, using all-suture anchors, using an arthroscopic transosseous knotless anchor, the Buddy anchor technique, Steinmann pin anchoring, and transosseous suture repair technology.

DISCUSSION

However, not many of the management techniques have been widely used in clinical practice. Most of them come from in vitro biomechanical studies, so in vivo randomized controlled trials with larger sample sizes are needed to see if they can help patients in the long run.

Perianchor cyst formation in all-suture anchor after rotator cuff repair: an evaluation of anchor insertion angle

BACKGROUND

Previous studies reported that micromotion after all-suture anchor implantation can lead to perianchor cyst formation (PCF), leading to risk of retear. Modifying anchor insertion angle (AIA) is known to be one of the various ways to increase anchor stability. However, there currently are few studies that assess the correlation between PCF, AIA, and retear.

PURPOSE

To find the correlation of PCF and the repaired rotator cuff integrity with AIA after arthroscopic double-row suture-bridge rotator cuff repair (RCR) using an all-suture anchor in the medial row.

METHODS

A total of 218 patients who underwent arthroscopic double-row suture-bridge RCR were retrospectively reviewed. All patients underwent RCR using all-suture anchors and polyether ketone anchors in the medial and lateral rows, respectively. Magnetic resonance imaging was conducted 6 months after the surgery to evaluate PCF, AIA, and integrity of the repaired cuff. The all-suture anchor insertion angle in the medial row was measured with reference to the greater tuberosity to assess the relationship between the AIA and PCF. The correlations between PCF, AIA, and post-RCR integrity were evaluated including various demographic and radiologic factors.

RESULTS

Perianchor cysts were formed in 93 patients (42.7%). Mediolateral tear size (2.1 ± 1.2 cm vs. 1.7 ± 0.9 cm, P = .034) and AIA (61.9° ± 15.2° vs. 68.4° ± 13.0°, P = .001) were significantly different between patient groups with and without perianchor cysts. Multivariate logistic regression analysis showed that mediolateral tear size (odds ratio [OR] 1.318, 95% confidence interval [CI] 1.008-1.724; P = .043) and AIA (OR 0.967, 95% CI 0.947-0.988; P = .002) were independent risk factors for PCF. In addition, PCF was observed more frequently (69.6% vs. 32.1%, P < .001) and the AIA was lower (59.4° ± 13.7° vs. 67.8° ± 13.8°, P < .001) in the retear group than in the healed group.

CONCLUSIONS

Perianchor cysts were formed in approximately 40% of patients who underwent arthroscopic double-row suture-bridge RCR using all-suture anchors. Low AIA and large mediolateral tear size were risk factors for PCF. Moreover, perianchor cyst and AIA were correlated with post-RCR integrity. Therefore, a high AIA must be carefully considered when all-suture anchors are inserted into the medial row when performing RCR.

Biomechanical properties of a suture anchor system from human allogenic mineralized cortical bone matrix for rotator cuff repair

Background

Suture anchors (SAs) made of human allogenic mineralized cortical bone matrix are among the newest developments in orthopaedic and trauma surgery. Biomechanical properties of an allogenic mineralized suture anchor (AMSA) are not investigated until now. The primary objective was the biomechanical investigation of AMSA and comparing it to a metallic suture anchor (MSA) and a bioabsorbable suture anchor (BSA) placed at the greater tuberosity of the humeral head of cadaver humeri. Additionally, we assessed the biomechanical properties of the SAs with bone microarchitecture parameters.

Methods

First, bone microarchitecture of 12 fresh frozen human cadaver humeri from six donors was analyzed by high-resolution peripheral quantitative computed tomography. In total, 18 AMSAs, 9 MSAs, and 9 BSAs were implanted at a 60° angle. All three SA systems were systematically implanted alternating in three positions within the greater tuberosity (position 1: anterior, position 2: central, position 3: posterior) with a distance of 15 mm to each other. Biomechanical load to failure was measured in a uniaxial direction at 135°.

Results

Mean age of all specimens was 53.6 ± 9.1 years. For all bone microarchitecture measurements, linear regression slope estimates were negative which implies decreasing values with increasing age of specimens. Positioning of all three SA systems at the greater tuberosity was equally distributed (p = 0.827). Mean load to failure rates were higher for AMSA compared to MSA and BSA without reaching statistical significance between the groups (p = 0.427). Anchor displacement was comparable for all three SA systems, while there were significant differences regarding failure mode between all three SA systems (p < 0.001). Maximum load to failure was reached in all cases for AMSA, in 44.4% for MSA, and in 55.6% for BSA. Suture tear was observed in 55.6% for MSA and in 22.2% for BSA. Anchor breakage was solely seen for BSA (22.2%). No correlations were observed between bone microarchitecture parameters and load to failure rates of all three suture anchor systems.

Conclusions

The AMSA showed promising biomechanical properties for initial fixation strength for RCR. Since reduced BMD is an important issue for patients with chronic rotator cuff lesions, the AMSA is an interesting alternative to MSA and BSA. Also, the AMSA could improve healing of the enthesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05371-0.

Subpectoral Biceps Tenodesis Using an All-Suture Anchor

Long head biceps tendon pathology is a substantial contributor to anterior shoulder pain and often requires surgical intervention to offer a return to normal functionality. Surgical treatment options consist of both open and arthroscopic tenodesis or tenotomy of the long head biceps brachii. Several techniques exist for tenodesis and tenotomy of the biceps, although current debate continues regarding which surgical approach is the optimal intervention for symptomatic bicep pathology. In this technical note, we describe a subpectoral biceps tenodesis of the long head bicep tendon using an all-suture anchor. Our technique offers the advantages of using an all-suture anchor that incorporates a self-tensioning mechanism with direct visualization of the tendon during biceps tenodesis and anchor insertion.

Biomechanical analysis of bioabsorbable suture anchors for rotator cuff repair using osteoporotic and normal bone models

BACKGROUND

This study aimed to compare the failure load of suture anchors used in rotator cuff repair between normal and osteoporotic bone models.

METHODS

A total of 16 anchors made from metal (TwinFix Ti 5.0 or 6.5 mm, Corkscrew FT 4.5, 5.5, or 6.5 mm), polyether ether ketone (HEALICOIL PK [HC-PK] 4.5 or 5.5 mm, SwiveLock PK 4.75 or 5.5 mm), or bioabsorbable material (HEALICOIL RG [HC-RG] 4.75 or 5.5 mm, Corkscrew Bio 4.75, 5.5, or 6.5 mm, SwiveLock BC 4.75 or 5.5 mm) were included. Moreover, 10- and 5-pounds per cubic foot (pcf) Sawbone® models were set as normal and osteoporotic cancellous bone models, respectively. Pullout testing was performed in parallel to the insertion axis at a displacement rate of 12.5 mm/s using a universal testing machine. To evaluate the change in failure load between the two Sawbone® models with different densities, the remaining failure load ratio (RFLR) was defined as the ratio of the failure load in 10 pcf to that in 5 pcf.

RESULTS

In the 10-pcf Sawbone®, TwinFix Ti 6.5 mm showed the highest mean failure load (304.0 ± 15.2 N). In the 5-pcf Sawbone® model, HC-PK 5.5 mm showed the highest failure load (146.3 ± 5.8 N). Among anchors with the same diameter, HC-PK and HC-RG showed a significantly higher failure load than other anchors in the 10- and 5-pcf Sawbone® models. HC-PK 5.5 mm (62.1%) and HC-PK 4.5 mm (51.1%) have the highest RFLR among anchors with the same diameter.

CONCLUSIONS

HC-PK and HC-RG showed higher failure load than the other anchors in both normal and osteoporotic bone models, except for TwinFix Ti 6.5 mm in the 10-pcf Sawbone® model. Based on our results, bioabsorbable anchors had sufficient failure load for rotator cuff repair in addition to bioabsorbability.

Knotless PEEK and double-loaded biodegradable suture anchors ensure comparable clinical outcomes in the arthroscopic treatment of traumatic anterior shoulder instability: a prospective randomized study

PURPOSE

To compare the clinical outcome of arthroscopic capsulolabral repair for traumatic anterior shoulder instability with PEEK knotless and knotted 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: knotless PEEK anchors in group 1, and biodegradable anchors in group 2. Exclusion criteria were: instability without dislocation, posterior or multidirectional instability, glenoid bone loss > 20%, off-track lesions, concomitant rotator cuff tears and previous surgery. The primary outcome was the Disabilities of the Arm, Shoulder and Hand (DASH) self-administered questionnaire. Secondary outcomes were: Work-DASH, Sport-DASH, Rowe score, recurrent instability and subsequent surgery. The following independent variables were considered: age, gender, dominance, generalized ligamentous hyperlaxity, duration of symptoms, age at first dislocation, number of dislocations, type of work, type of sport, sports activity level, capsule-labral injury pattern, SLAP lesion and number of anchors. Differences between groups for numerical variables were analyzed by use of the Student's t-test or Mann-Whitney U-test. Fisher's exact test was used for analysis of categorical variables. Significance was set at p < 0.05.

RESULTS

Seven patients (9%) were lost at follow-up, 5 from group 1 and 2 from group 2. Follow-up ranged from 36 to 60 months (median: 44; IQR: 13). Comparison between groups did not show significant differences for each independent variable considered. No differences could be found either for DASH (n.s.) or Rowe (p = n.s.) scores between the two groups. Overall recurrence rate was 7%. Three re-dislocations were reported in group 1 and two in group 2 (n.s.). Only one patient in each group underwent re-operation.

CONCLUSIONS

The study showed no significant differences in clinical outcomes after arthroscopic treatment of traumatic anterior shoulder instability using PEEK knotless or biodegradable knotted anchors at mid-term follow-up.

LEVEL OF EVIDENCE

I.

Bioclickable Mussel-Derived Peptides With Immunoregulation for Osseointegration of PEEK

Polyether ether ketone (PEEK)–based biomaterials have been widely used in the field of spine and joint surgery. However, lack of biological activity limits their further clinical application. In this study, we synthesized a bioclickable mussel-derived peptide Azide-DOPA₄ as a PEEK surface coating modifier and further combined bone morphogenetic protein 2 functional peptides (BMP2p) with a dibenzylcyclooctyne (DBCO) motif through bio-orthogonal reactions to obtain DOPA₄@BMP2p-PEEK. As expected, more BMP2p can be conjugated on PEEK after Azide-DOPA₄ coating. The surface roughness and hydrophilicity of DOPA₄@BMP2p-PEEK were obviously increased. Then, we optimized the osteogenic capacity of PEEK substrates. In vitro, compared with the BMP2p-coating PEEK material, DOPA₄@BMP2p-PEEK showed significantly higher osteogenic induction capability of rat bone marrow mesenchymal stem cells. In vivo, we constructed a rat calvarial bone defect model and implanted PEEK materials with a differently modified surface. Micro-computed tomography scanning displayed that the DOPA₄@BMP2p-PEEK implant group had significantly higher new bone volume and bone mineral density than the BMP2p-PEEK group. Histological staining of hard tissue further confirmed that the DOPA₄@BMP2p-PEEK group revealed a better osseointegrative effect than the BMP2p-PEEK group. More importantly, we also found that DOPA₄@BMP2p coating has a synergistic effect with induced Foxp3+ regulatory T (iTreg) cells to promote osteogenesis. In summary, with an easy-to-perform, two-step surface bioengineering approach, the DOPA₄@BMP2p-PEEK material reported here displayed excellent biocompatibility and osteogenic functions. It will, moreover, offer insights to engineering surfaces of orthopedic implants.

Periimplant osteolysis does not affect the outcome of rotator cuff repair: a systematic review and meta-analysis

PURPOSE

The goal of this study was to perform a systematic review and meta-analysis to compare the clinical and radiologic outcomes of rotator cuff repair, depending on the presence of developed periimplant osteolysis (PIO) after using suture anchors.

METHODS

The electronic databases of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for articles published up until October 2019 to find relevant articles comparing the outcomes of rotator cuff repair between the periimplant osteolysis group and non-periimplant osteolysis group. Data searching, extraction, analysis, and quality assessment were performed according to the Cochrane Collaboration guidelines. The results are presented as risk ratio (RR) for binary outcomes and standardised mean difference (SMD) for continuous outcomes with 95% confidence intervals (CI).

RESULTS

Six clinical studies were included. No significant differences were found between the group with periimplant osteolysis and the group without periimplant osteolysis regarding retear rate (RR = 1.34; 95% CI 0.93-1.94; I² = 28%), postoperative clinical scores (SMD = 0.29; 95% CI - 0.26 to 0.83; I² = 80%) and range of motion (ROM); forward flexion (SMD = 0.39; 95% CI - 0.16 to 0.93; I² = 0%), external rotation (SMD = - 0.10; 95% CI - 0.64 to 0.45; I² = 0%) and internal rotation (SMD = - 0.37; 95% CI - 0.92 to 0.17; I² = 0%).

CONCLUSION

The presence of periimplant osteolysis after rotator cuff repair with suture anchor does not affect the clinical outcomes such as retear rate, clinical scoring, and ROM. However, as there was no standard consensus on the criteria for evaluating periimplant osteolysis, this result may not fully reflect the effect of periimplant osteolysis depending on its severity.

LEVEL OF EVIDENCE

Level IV.

Editorial Commentary: Early Detection and Treatment Improves Short-Term Outcomes After Shoulder Anchor Arthropathy, but an Ounce of Prevention Is Worth a Pound of Cure

Anchor arthropathy is a rare, but devastating, complication after arthroscopic labral repair and shoulder stabilization. Early recognition and treatment in the form of removal of anchor and suture material, loose bodies, and potential revision stabilization significantly improve short-term outcomes. The entity of anchor arthropathy may be difficult to diagnose, and a high index of suspicion is needed when a patient presents postoperatively with pain and stiffness beyond atypical for their time in rehab. In the end, while early treatment can be favorable, prevention with meticulous attention to detail on anchor placement, position, and potential use of knotless anchors is strongly recommended.

Postoperative Stiffness and Pain After Arthroscopic Labral Stabilization: Consider Anchor Arthropathy

PURPOSE

To describe the key clinical, imaging, and arthroscopic characteristics of anchor arthropathy after arthroscopic shoulder stabilization procedures and, secondarily, to define risk factors for the development of anchor-induced arthropathy.

METHODS

A total of 23 patients who underwent revision arthroscopic shoulder surgery and were diagnosed with glenohumeral arthropathy were retrospectively identified from prospectively collected data registries between January 2000 and May 2018. Data included initial diagnosis and index procedure performed, presenting arthropathy symptoms including duration, and examination findings before revision surgery. Pre-revision imaging was used to assess presence of glenohumeral osteoarthritis and chondromalacia, anchors/sutures, loose bodies, and labral pathology. The same parameters were recorded intraoperatively during revision surgery. Descriptive statistics were performed for demographic data and means with standard deviations were calculated for continuous data. A McNemar-Bowker test was used to analyze marginal homogeneity between preoperative imaging and intraoperative findings.

RESULTS

Mean age at presentation was 33.4 ± 11.7 years (range 16-59, 17 male patients; 6 female patients). More than one half (13/23) developed symptoms within 10 months after index arthroscopic procedure (mean 32.2 ± 59.9 months, range <1 to 165.2 months) with 87% presenting with pain and 100% presenting with loss of motion on examination. Plain radiographs demonstrated humeral osteoarthritis in 57% (13/23) of patients, magnetic resonance imaging (MRI) revealed recurrent labral pathology in 19 of 23 (83%) patients, potential proud implants in 12 of 23 (52%), and loose bodies in 12 of 23 (52%). Intraoperatively, all had evidence of osteoarthritis; 22 of 23 (96%) had prominent implants. Humeral head chondromalacia was present in 21 of 23 patients (91%), the majority of which was linear stripe wear, and 6 of 23 (26%) had severe global glenohumeral osteoarthritis. Statistical analysis revealed a 54.5% (95% confidence interval 0.327-0.749) sensitivity of MRI identification of proud implants with a specificity of 100% (95% confidence interval 0.055-1). The ability of MRI to accurately assess chondromalacia of the humeral head (P = .342) or glenoid (P = .685) was not statistically significant.

CONCLUSIONS

Anchor arthropathy is characterized by symptoms of pain and stiffness on examination and in many cases develops early after stabilization surgery (<10 months). Implants were implicated in the majority of cases of humeral head chondromalacia. MRI scans may produce false-negative identification of proud implants and can be a poor predictor of the severity of chondromalacia and intra-articular pathology; thus, a high index of clinical suspicion is necessary in patients with motion loss and pain postoperatively.

LEVEL OF EVIDENCE

Level IV, case series.

Simultaneous repair of bilateral pectoralis major tendons: A case report

BACKGROUND

Injuries to the pectoralis major are infrequent, with only a few hundred cases currently recorded in the literature.

CASE SUMMARY

We report a case of a patient who sustained bilateral pectoralis major tendon ruptures. While other cases of bilateral pectoralis major tears have been reported in the literature, the operative management in this report differs. Due to delayed presentation of the patient right and left pectoralis major repairs were performed simultaneously.

CONCLUSION

Patients with delayed presentation of bilateral pectoralis major tendon ruptures can undergo simultaneous repair of both tendon with a good postoperative outcome and high patient satisfaction.

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.

Single-Portal, Single-Anchor Repair of a Superior Third Subscapularis Tear Using a Self-Punching Knotless Soft Suture Anchor

Numerous techniques exist for arthroscopic subscapularis repair with varying degrees of complexity based on tear morphology, all of which have established satisfactory outcomes in function and patient satisfaction. Arthroscopic subscapularis repair can require several working portals and suture anchors, increasing both technical complexity and operative time. This Technical Note describes an arthroscopic repair of a superior one-third subscapularis tear using a self-punching knotless soft suture anchor through a single anterior working portal. Thus, we offer a unique approach to arthroscopic repair of superior one-third subscapularis tears that is time-saving, reproducible, and highly efficient while minimizing iatrogenic damage and postoperative complications.

Arthroscopic remplissage with all-suture anchors causes cystic lesions in the humerus: a volumetric CT study of 55 anchors

PURPOSE

To evaluate with computed tomography (CT) the incidence of implant-related osteolysis after implantation of two types of all-suture anchors during remplissage for the management of Hill-Sachs lesions in shoulder instability.

METHODS

Single-cohort, observational study with a minimum of 12 months follow-up. Twenty-five participants (19 males and 6 females; mean age 37.4 years [SD: 11.6]) with Hill-Sachs lesions requiring remplissage were evaluated with a CT performed a mean of 14.1 [3.74] months after surgery. Fifty-five all-suture anchors (19 2.3 mm Iconix and 36 1.7 mm Suturefix) were used. The volume of the bone defects was measured in the CT. Every anchor was classified into one of four groups: (1) no bone defect. (2) Partial bone defect (bone defects smaller than the drill used for anchor placement). (3) Tunnel enlargement (bone defect larger than the drill volume but smaller than twice that volume). (4) Cystic lesion (bone defect larger twice the drill volume).

RESULTS

No bone defect was identified in only two anchors (3.6%, 95% CI 0.4-12.5%). A partial bone defect was found in eight anchors (14.5%, 95% CI 6.5-26.7%). In 35 anchors (63.6%, 95% CI 49.6-76.2%), there was enlargement of the bone defect that was smaller than 200% the size of the drill used. Ten anchors caused bone defects larger than twice the size of the drill used (18.2%, 95% CI 9.1-30.9%). The defect size was a mean of 89 mm³ (SD: 49 mm³, minimum 0 mm³, maximum 230 mm³).

CONCLUSION

When using all-suture anchors in arthroscopic remplissage during instability surgery, relevant bone osteolytic defects are common at 1-year-follow-up. Cystic defects larger than twice the volume of the resected bone during implantation develop in one in six anchors and significant tunnel widening will develop in another three out of five anchors. This bone loss effectively increases the size and depth of the Hill-Sachs lesions but does not seem to affect short-term clinical outcomes.

LEVEL OF EVIDENCE

Level IV.

Arthroscopic Bankart repair with all-suture anchors does not cause important glenoid bone osteolysis: a volumetric CT study of 143 anchors

PURPOSE

To evaluate with computed tomography (CT) the incidence of anchor-related osteolysis after implantation of two types of all-suture anchors for the management of labral lesions in shoulder instability.

METHODS

Single-cohort, observational study with 12-month follow-up. Thirty-three participants (27 males/6 females; age 38.3 years [SD 11.3]) with anterior labral lesions in which 143 all-suture anchors (71 Iconix 1.4 mm and 72 Suturefix 1.7 mm) were implanted were evaluated with a CT performed a mean of 15.4 [3.85] months after surgery. The volume of the bone defects was measured in the CT. Every anchor was classified into one of four groups: (1) no bone defect. (2) Partial bone defect (defects smaller than the drill used for anchor placement). (3) Tunnel enlargement (defects larger than the drill volume but smaller than twice that volume). (4) Cystic lesion (defects larger than twice the drill volume).

RESULTS

No bone defect was identified in 16 anchors (11.2%, [95% CI 6.5-17.5%]). A partial bone defect was found in 84 anchors (58.7% [50.2-66.9%]). Tunnel enlargement was found in 43 anchors (30.11% [22.6-37.6%]). No anchor caused cystic lesions (0% [0-2.5%]). The defect volume was a mean of 27.8 mm³ (SD 18.4 mm³, minimum 0 mm³, maximum 94 mm³). Neither the position in the glenoid nor the type of implant used had a significant effect in the type or size of the defects.

CONCLUSION

When using all-suture anchors in the glenoid during instability surgery, relevant bone osteolytic defects are rare at 1-year follow-up. Most anchor insertion tunnels will fill completely (11%) or partially (59%) with bone. Tunnel enlargement will develop in 30% of anchors. No cystic defects larger than 0.125 cm³ were observed. There is a low risk that all-suture anchors cause significant osteolytic bone defects in the glenoid. These implants can be used safely. Level of evidence IV.

Preliminary Clinical and Radiographic Evaluation of a Novel Resorbable Implant of Polylactic Acid (PLA) for Tibial Tuberosity Advancement (TTA) by Modified Maquet Technique (MMT)

Our objectives were to determine whether PLA implants can be used in TTA with successful results; secondly, to observe whether they provide a faster bone healing; finally, to determine whether weight or age influences bone healing scores. PLA cages were created with a 3D printer. TTA by MMT with PLA implants was performed in 24 patients. Follow-ups were carried out pre-surgical, at 1, 2, and 5 months and consisted of a radiographic study and a lameness assessment. A comparison was performed in terms of weight and age. Patients data, time between follow-up examinations, healing score, and lameness score were compared between patients using commercial software for statistically significant differences p < 0.05. Eighteen dogs finished the study. The ossification degrees presented statistically significant differences between each other. PLA implants maintained the advancement in 100% of cases. Comparing weight and age did not present any statistically significant differences between groups. Lameness presented statistically significant differences between follow-up examinations. Complications were observed in 20.8%. PLA implants for TTA provide good functional results, presenting an acceptable rate of complications. They provide a faster bone healing of the osteotomy gap, which was not affected by age or body weight, and have a clinical recovery time similar to metallic implants.

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.

Needle-Based Arthroscopic Transosseous Rotator Cuff Repair: A Short-Term Outcomes Analysis

Introduction Given the limitations of anchor-based rotator cuff repair, surgeons have considered and investigated the use of an arthroscopic transosseous repair technique using only sutures to repair tendon tissue. Returning full circle to the gold standard of transosseous repair, but with the modern adaptation of arthroscopy, advocates of arthroscopic transosseous rotator cuff repair believe that many of the risks associated with suture anchors can be avoided. The purpose of this study was to examine the capabilities of a novel needle-based arthroscopic transosseous tunneling device (OmniCuff™ arthroscopic transosseous device, MinInvasive Ltd., Magal, Israel) and evaluate the short-term clinical outcomes and patient satisfaction of patients treated with this technique. Materials and methods This study was a prospective, single-arm, multi-center study performed on patients from January 2014 to March 2015. During the study period, thirty-two patients underwent arthroscopic transosseous rotator cuff repair using the OmniCuff™ arthroscopic transosseous device. Results The average age of patients was 58.2 years (range, 44 to 80 years). The sizes of the tears were as follows: seven small, 18 medium, four large, and three massive. The average number of tunnels used per repair was 1.9 with the following breakdown: six one-tunnel repairs, 22 two-tunnel repairs, and four three-tunnel repairs. The mean American Shoulder and Elbow Surgeon (ASES) score improved from 45.1 to 87.7, the mean Simple Shoulder Test (SST) score improved from 42.6 to 92. Overall patient satisfaction was high with an average Likert scale of 4.6. Conclusion Our study demonstrated significantly improved outcomes for patients undergoing arthroscopic transosseous rotator cuff repair using the needle based Omnicuff device. Patients were overall very satisfied with the outcome of their surgery and their ASES and SST scores demonstrated this appropriately.

All-suture anchors versus metal suture anchors in the arthroscopic treatment of traumatic anterior shoulder instability: A comparison of mid-term outcomes

OBJECTIVES

This study aims to compare metal suture anchors and all-suture anchors clinically and radiologically in arthroscopic Bankart repair.

PATIENTS AND METHODS

In this retrospective study, 67 patients (61 males, 6 females; mean age 26.0±5.8; range, 18 to 43 years) who underwent arthroscopic Bankart repair between April 2009 and October 2016 were divided into two groups depending on the type of the suture anchor used in different periods. Group A comprised 32 patients with arthroscopic Bankart repair performed with metal suture anchors, and Group B comprised 35 patients with arthroscopic Bankart repair performed with all-suture anchors. The patients were clinically evaluated using Rowe scores, Constant scores, redislocation rates, and positive apprehension test rates. Radiographic evaluation was performed using the Samilson-Prieto classification to observe the development of glenohumeral osteoarthritis.

RESULTS

The mean follow-up period was 41.1±10.4 (range, 30 to 60) months in Group A, and 39.6±9.4 (range, 28 to 60) months in Group B, with no significant difference between the two groups (p=0.559). No significant difference was observed between Group A and Group B in terms of mean Rowe score (89.2±13.8 [range, 40 to 100] vs. 88.7±16.9 [range, 25 to 100]; p=0.895) or Constant score (87.2±8.9 [range, 48 to 96] vs. 86.9±9.0 [range, 46 to 96]; p=0.878), which were the clinical outcomes at the final follow-up examination. Postoperative redislocation rates (3.1% vs. 2.9%, p=1.0) and positive apprehension test rates (6.3% vs. 8.6%, p=1.0) were found to be similar in both groups. According to the Samilson-Prieto classification, there was no evidence of glenohumeral osteoarthritis in any of the patients in either group.

CONCLUSION

Satisfactory outcomes were obtained with the use of all-suture anchors in arthroscopic Bankart repair for traumatic anterior shoulder instability. All-suture anchors and metal suture anchors, have similar outcomes in the mid-term and all-suture anchors are a reliable and effective option for arthroscopic Bankart repair.

Peri-anchor cyst formation after arthroscopic bankart repair: comparison between biocomposite suture anchor and all-suture anchor

Background

The purpose of this study is to investigate clinical outcomes and radiological findings of cyst formation in the glenoid around suture anchors after arthroscopic Bankart repair with either biocomposite suture anchor or all-suture anchor in traumatic anterior shoulder instability. We hypothesized that there would be no significant difference in clinical and radiological outcomes between the two suture materials.

Methods

This retrospective study reviewed 162 patients (69 in group A, biocomposite anchor; 93 in group B, all-suture anchor) who underwent arthroscopic Bankart repair of traumatic recurrent anterior shoulder instability with less than 20% glenoid defect on preoperative en-face view three-dimensional computed tomography. Patient assignment was not randomized.

Results

At final follow-up, the mean subjective shoulder value, Rowe score, and University of California, Los Angeles shoulder score improved significantly in both groups. However, there were no significant differences in functional shoulder scores and recurrence rate (6%, 4/69 in group A; 5%, 5/93 in group B) between the two groups. On follow-up magnetic resonance arthrography/computed tomography arthrography, the incidence of peri-anchor cyst formation was 5.7% (4/69) in group A and 3.2% (3/93) in group B, which was not a significant difference.

Conclusions

Considering the low incidence of peri-anchor cyst formation in the glenoid after Bankart repair with one of two anchor systems and the lack of association with recurrence instability, biocomposite and all-suture anchors in Bankart repair yield satisfactory outcomes with no significant difference.

Arthroscopic Bankart repair with knotless suture anchors: A comparison of the permanent and absorbable types

Aim:

The aim of this study was to compare the clinical outcomes of arthroscopic Bankart repair (ABR) using two types of knotless suture anchors (KSAs) in patients with post-traumatic recurrent anterior glenohumeral instability (AGHI).

Methods:

Thirty-two patients underwent an ABR using KSAs: a permanent KSA (PushLock) and an absorbable counterpart (BioKnotless). There were 16 patients in each group. Pre-and post-operative assessment for shoulder function using the American Shoulder and Elbow Surgeons and Constant–Murley scores, recurrence of instability, post-operative limitation of external rotation (ER) and ability to return to pre-injury level were recorded in both groups.

Results:

Both groups displayed significant improvements in functional scores ( p < 0.0001) without a significant difference between the groups. Of the 32 patients, 9.4% had recurrence of instability (one re-dislocation in group 1 and two symptomatic subluxations in group 2). Return to pre-injury level occurred in 87.5% and 81.3% of group 1 and group 2, respectively. There was 2° to 3° loss of ER after ABR in both groups; the difference between the groups was not significant ( p = 0.45).

Conclusion:

ABR for recurrent AGHI using a permanent or absorbable KSA offers comparable successful outcomes; no significant statistical difference was found.

Large Drill Holes Are Still Present in the Long Term After Arthroscopic Bankart Repair With Absorbable Tacks: An 18-Year Randomized Prospective Study

BACKGROUND

Studies have demonstrated the development of an osseous reaction at the drill sites of anchors after arthroscopic shoulder surgery.

PURPOSE

To investigate the drill-hole size at 18 years after arthroscopic Bankart repair using either fast polygluconate acid (PGA) or slow polylevolactic acid (PLLA) absorbable tacks and to compare the functional outcomes and development of osteoarthritis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

40 patients with unidirectional anterior shoulder instability, treated with arthroscopic Bankart repair, were randomized into the PGA group (n = 20) or the PLLA group (n = 20). Plain radiographs of both shoulders, as well as computed tomography (CT) images of the operated shoulder, were used to evaluate the drill-hole size, volume, and degenerative changes. Functional outcomes were assessed by use of the Rowe score, Constant score, and Western Ontario Shoulder Instability (WOSI) index.

RESULTS

Of the 40 patients, 32 patients returned for the follow-up (15 PGA and 17 PLLA). No significant differences were found in the population characteristics between the study groups. The mean follow-up time was 18 years for both groups. No significant differences were seen in range of motion, strength in abduction, or Constant, Rowe, and WOSI scores between the groups. Recurrence rate was 33% in the PGA group and 6% in the PLLA group during the follow-up period (P = .07). The drill-hole appearance on plain radiographs (invisible/hardly visible/visible/cystic) was 11/2/2/0 and 6/5/5/1 for the PGA and PLLA groups, respectively (P = .036). The mean ± SD drill-hole volume as estimated on CT images was 89 ± 94 and 184 ± 158 mm³ in the PGA and PLLA groups, respectively (P = .051). Degenerative changes (normal/minor/moderate/severe) on plain radiographs were 7/4/4/0 and 3/8/5/1 for the PGA and PLLA groups, respectively (P = .21), and on CT images were 5/7/3/0 and 2/6/6/3 for the PGA and PLLA groups, respectively (P = .030).

CONCLUSION

This long-term follow-up study demonstrated that the PLLA group had significantly more visible drill holes than the PGA group on plain radiographs. However, this difference was not evident on CT imaging, with both groups having several visible cystic drill holes and a substantial drill-hole volume defect. No significant differences were found between the study groups in terms of clinical outcomes.

Incidence of Axillary Nerve Injury After Arthroscopic Shoulder Stabilization

PURPOSE

To investigate the incidence of axillary nerve palsy after arthroscopic shoulder stabilization and to measure the distance between the nerve and capsule in shoulders with a capsular lesion.

METHODS

This retrospective study included 2,027 shoulders (1,909 patients; 1,433 male and 476 female patients; mean age, 32 years [age range, 13-81 years]) subjected to arthroscopic soft-tissue stabilization for recurrent shoulder instability from 2005 to 2017. The exclusion criteria were bone grafting or transfer and preoperative axillary nerve symptoms. We retrospectively reviewed patient records and investigated the incidence and clinical features of axillary nerve palsy. We measured the closest distance between the axillary nerve and capsule on preoperative magnetic resonance images.

RESULTS

Postoperative axillary nerve palsy occurred in 4 shoulders (0.2% of all arthroscopic stabilizations). Capsular repair was performed in 2 shoulders (1.2% of 160 capsular repairs); humeral avulsion of the glenohumeral ligament (HAGL) repair, 1 shoulder (2% of 47 HAGL repairs); and isolated Bankart repair, 1 shoulder (0.05% of 1,941 Bankart repairs). The closest distance between the nerve and capsule was 3.4 ± 3.2 mm in shoulders with capsular or HAGL lesions and less than 1 mm in the 3 shoulders with palsy. The common symptoms in axillary nerve palsy cases were shoulder discomfort, delayed recovery of range of motion, and deltoid weakness and atrophy. A definitive diagnosis was made with electromyography in all cases. Nerve injury by a suture was confirmed during revision surgery in 3 shoulders subjected to capsular or HAGL repair during the initial operation. The palsy was transient and fully recovered in 1 shoulder with isolated Bankart repair.

CONCLUSIONS

The incidence of axillary nerve palsy after arthroscopic soft-tissue shoulder stabilization was low but higher in shoulders subjected to capsular or HAGL repair. We should always consider the possibility of axillary nerve palsy in shoulders that require capsular or HAGL repair.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Anchor placement to glenoid rim during Bankart repair recreates contact area of anterior capsulolabral complex on glenoid better than onto articular surface

PURPOSE

This study aimed to compare the contact areas of Bankart repair with suture anchors placed on the articular surface of the glenoid versus at the rim of the glenoid because it is unclear which technique most effectively restores the footprint after Bankart repair.

METHODS

Ten fresh frozen cadaveric shoulders (mean age 70.7 years) were dissected. The attachment site of the capsulolabral complex from the 1 o' clock position to the 6 o'clock position was marked with ink, and the contact area of the anterior-inferior capsulolabral complex on the glenoid neck was measured using imageJ. Bankart lesions were created, and two types of Bankart repair were performed on each specimen. The suture anchors were inserted at the glenoid rim (Rim group) and onto the glenoid articular surface 2 mm from the rim (Surface group). Using pressure-sensitive films, we examined the interface contact area.

RESULTS

The Rim group recreated 64.9% of the native surface area, while the Surface group recreated 47.3% of the area. The Rim group recreated significantly greater contact area compared to the Surface group (P = 0.0008).

CONCLUSION

The anchor placement to the glenoid rim recreates the footprint of the capsulolabral complex on the anterior inferior glenoid better than the anchor placement onto the articular surface.

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.

Contribution of postoperative ultrasound to early detection of anchor pullout after rotator cuff tendon repair: Report of 3 cases

INTRODUCTION

Rotator cuff repair by suture bridge is now widely used. Few studies reported secondary pullout of radiotransparent anchors. The aim of the present prospective study was to demonstrate the contribution of in-office ultrasonography to detect pullout, and to describe the examination procedure.

MATERIAL AND METHOD

A total of 102 patients underwent arthroscopic rotator cuff repair by suture bridge, with impacted second-row anchors. Ultrasonography was performed by the surgeon in postoperative consultations.

RESULTS

At 6 weeks' follow-up, 3 patients showed mean 2nd-row implant pullout of 8.3mm. All underwent arthroscopic revision to extract the implant, which was mobile within its tunnel in all cases. Clinical progression was good, with mean Constant score 72 and no aggravation of the lesion on ultrasound at 3 months' follow-up.

DISCUSSION

The present series would seem to be the first to report: early radiotransparent in-vivo pullout 6 weeks after suture bridge cuff repair; ultrasound detection of pullout in consultation by the orthopedic surgeon; a description of the ultrasound technique for screening this rare and specific problem.

CONCLUSION

Ultrasound now enables radiotransparent anchor positioning to be monitored following rotator cuff repair as of the first postoperative days, without compromising tendon healing.

LEVEL OF EVIDENCE

II.

A Comparison of Open-Construct PEEK Suture Anchor and Non-Vented Biocomposite Suture Anchor in Arthroscopic Rotator Cuff Repair: A Prospective Randomized Clinical Trial

PURPOSE

To compare radiologic bone ingrowth and the clinical outcomes of an open-construct (PEEK) (polyether ether ketone) suture anchor with those of a non-vented biocomposite suture anchor in patients with arthroscopic rotator cuff repair.

METHODS

Sixty-nine patients were randomly allocated into 2 groups based on type of suture anchors used for rotator cuff repair; group 1: open-construct PEEK anchor (36 patients), group 2: non-vented biocomposite anchor (33 patients). The status of bone ingrowth into the anchor and the presence of cyst formation were evaluated at 6 months postoperatively by computed tomography scan using the Modified Barber's ossification scale. The American Shoulder and Elbow Surgeons score, Constant score, and visual analog scale score for pain and range of motion were evaluated. Magnetic resonance imaging or ultrasonography was performed at 12 months postoperatively to examine the integrity of the repaired rotator cuff tendon.

RESULTS

Significant improvements in shoulder function and pain relief were observed regardless of the anchor used (both Group 1 and 2; P < .001). No differences were found in functional scores and range of motion between the 2 groups. Group 1 showed better bone ingrowth grades than group 2 (poor 2.8 vs 24.2%, fair 27.8 vs 39.4%, good 38.9 vs 33.3%, and excellent 30.6 vs 3.0%; P < .001). The rate of cyst formation around the anchor on the 6 months' postoperative computed tomography (group 1: 14% and group 2: 12%) and re-tear rate at 12 months (5% each) showed no difference between the 2 groups.

CONCLUSIONS

Shoulder function was improved after complete rotator cuff repair and similar clinical outcomes were achieved regardless of suture anchor material and shape. However, the open-construct PEEK anchor provided better bone ingrowth into the anchor than the non-vented biocomposite anchor at 6 months after arthroscopic rotator cuff repair.

LEVEL OF EVIDENCE

Level I; Prospective Randomized Trial.

Biomechanical Evaluation of Proximal Hamstring Repair: All-Suture Anchor Versus Titanium Suture Anchor

Background:

Proximal hamstring avulsions are severe tendon injuries and are commonly sports-related. Open and endoscopic techniques as well as different anchor configurations have already been described for proximal hamstring repair. Novel all-suture anchors have been developed to provide decreased bone loss during placement and reduced occupied bone volume when compared with titanium suture anchors.

Hypothesis:

Complete proximal hamstring avulsions repaired with all-suture anchors will demonstrate equal load to failure and comparable displacement under cyclic loading when compared with titanium suture anchors.

Study Design:

Controlled laboratory study.

Methods:

Complete proximal hamstring avulsions were created in 18 paired cadaveric specimens (mean ± SD age, 63.0 ± 10.4 years). Either all-suture anchors or titanium suture anchors were used for repair. Cyclic loading from 10 to 125 N at 1 Hz was performed for 1500 cycles with a material testing machine. Displacement was assessed along anterior and posterior aspects of the tendon repair with optical tracking. Specimens were loaded to failure at a rate of 120 mm/min. Displacement, load to failure, and repair construct stiffness were compared between matched pairs with the Wilcoxon signed-rank test. Correlations were determined by Spearman rho analysis.

Results:

The all-suture anchors showed significantly higher load-to-failure values when compared with the titanium anchor repairs (799.64 ± 257.1 vs 573.27 ± 89.9 N; P = .008). There was no significant difference in displacement between all-suture anchors and titanium suture anchors at the anterior aspect (6.60 ± 2.2 vs 5.49 ± 1.1 mm; P = .26) or posterior aspect (5.87 ± 2.08 vs 5.23 ± 1.37 mm; P = .678) of the repaired hamstring tendons.

Conclusion:

All-suture anchors demonstrated similar displacement and superior load to failure when compared with titanium suture anchors.

Clinical Relevance:

The results of this study suggest that all-suture anchors are an equivalent alternative to titanium suture anchors for proximal hamstring avulsion repair.

Biological response to an experimental implant for tibial tuberosity advancement in dogs: A pre-clinical study

In this study, we propose a novel bioresorbable bioactive implant for tibial tuberosity advancement (TTA). The implant consists of a gradually resorbing load-bearing shell which encompasses rapidly resorbing small casings loaded with silica-based bioactive glass (BG) particulates which promote bone formation and reduce the risk of infection. The shell and the casings are manufactured by 3D printing from two medical grade bioresorbable polymers (a polyglycolide/lactide based and a polydioxanone based) that have different degradation rates. The casings are expected to resorb within days after surgery to expose the BG particulates while the shell would retain the load-bearing properties of the implant for the time required by bone healing. Unlike the currently used metallic devices, the novel implant is resorbed and excreted from the body once its purpose is fulfilled. This study presents a logical progression from the in vitro characterisation of the materials and implants to the in vivo investigation of the experimental implants. This included mechanical testing of the materials, finite element analysis of a preliminary design of the novel TTA implant, assessment of the degradation behaviour of the polymers and the ion exchange of BG in simulated body fluid, and investigation of the biological response to the novel implants after implantation in rabbits. The osteointegration of the novel implants was comparable to the osteointegration of Ti6Al4V implants in the control group; the biological efficacy and safety were confirmed. The biological response was in line with the expectations. The proof of concept for the novel TTA implants was demonstrated.

The formation of perianchor fluid associated with various suture anchors used in rotator cuff repair

Aims

The aim of this study was to compare the osseous reactions elicited by all-suture, polyetheretherketone (PEEK), and two different biodegradable anchors used during rotator cuff repair.

Patients and Methods

Transosseous-equivalent rotator cuff repair was performed in 73 patients. The patients were divided into two groups, in both of which two different medial-row anchors were used. In group 1, anchor A comprised 30% β-tricalcium phosphate (TCP) + 70% fast-absorbing poly lactic-co-glycolic acid copolymer (85% polylactic acid enantiomers + 15% polyglycolic acid) and anchor B comprised all-sutures. In group 2, anchor C comprised 23% micro β-TCP + 77% polylactic acid enantiomers and anchor D comprised PEEK polymer. There were 37 patients in group 1 and 36 patients in group 2. The presence and severity of fluid collection around anchors and healing of the rotator cuff were assessed using MRI scans, approximately one year postoperatively. The severity of the collection was graded as 0 (no perianchor fluid signal), 1 (minimal perianchor fluid), 2 (local collection of fluid), 3 (fluid collection around the whole length of the anchor but of a diameter less than twice the anchor diameter), or 4 (fluid collection around the whole length of the anchor and of a diameter greater than twice the anchor diameter).

Results

A perianchor fluid signal was seen in three patients (8.1%) with anchor A, four (10.8%) with anchor B, 15 (41.7%) with anchor C, and 15 (41.7%) with anchor D. The severity of the collection around anchor was grade 2:1:0:0 for anchor A, grade 2:2:0:0 for anchor B, grade 12:2:0:1 for anchor C, and grade 11:3:0:1 for anchor D (grade 1:2:3:4, respectively). The prevalence and severity of fluid formation was not significantly different between anchors A and B, and anchors C and D. However, on intergroup analysis, there were significant differences for the prevalence and severity of fluid formation between anchors in group 1 and group 2. The prevalence of failure to heal was not significant in group 1 (seven, 18.9%) or group 2 (nine, 25.0%). There was no relationship between the presence of perianchor fluid and each type of anchor, and the integrity of the rotator cuff repair, in either group.

Conclusion

Despite the nonabsorbable nature of all-suture and PEEK anchors, all-suture anchors produced less osseous reaction after rotator cuff repair. In deciding which kind of anchor to use, consideration should be given not only to the strength of the initial fixation, but also to the postoperative biological reaction. Cite this article: Bone Joint J 2019;101-B:1506–1511