Solid Anchors Research Articles

All-Suture and Solid Medial Row Anchors Produce Similar Clinical Outcomes for Double Row Suture Bridge Rotator Cuff Repair (227)

Objectives:All-suture anchor use for rotator cuff repair is increasing. Potential benefits of these anchors include less bone loss from anchor hole drilling and decreased injury to the chondral surface with anchor pullout. Minimal evidence exists comparing clinical outcomes of all suture to solid medial row anchor fixation in double row suture bridge rotator cuff repair. The purpose of this study was to compare patient-reported outcomes for rotator cuff tears treated with all-suture medial row anchors to those treated with more traditional solid anchors. The null hypothesis was that there is no difference in outcomes between the all-suture and solid anchor rotator cuff repairs.Methods:Three sports medicine fellowship trained surgeons performed rotator cuff repairs using the double row suture bridge technique with minimum 3 years of follow up. Patients were separated into two groups based on whether or not they received all-suture or solid anchor fixation for the medial row of their repair. All lateral row fixation was performed with solid anchors. Primary outcomes were evaluated with telephone follow-up and included the American Shoulder and Elbow Surgery Score (ASES), Single Assessment Numeric Evaluation (SANE), and Visual Analog Scale (VAS). The Rehabilitation protocol was the same for all subjects in the study.Results:3 sports medicine fellowship trained orthopaedic surgeons performed 153 rotator cuff repairs. 91 of these subjects had all-suture fixation of the medial row and 62 received solid anchor fixation. Follow up was 3.6 years ± 0.6 for the all-suture group and 3.7 years ± 0.6 in the solid anchor group (p= 0.28). ASES scores were 92 ± 16 in the all-suture group and 90 ± 17 in the solid group (p =0.35). SANE scores were 91 ± 13 in the all-suture and also 91 ± 13 in the solid anchor cohort (p = 0.97). VAS scores were 1.1 ± 2.0 in the all-suture and 0.7± 1.8 in the solid anchor group (p=0.17). There were no significant differences between groups with regards to re-operation rate or anchor configuration.Conclusions:All suture anchors used in medial row fixation for double row suture bridge rotator cuff repairs have similar clinical outcomes to rotator cuff tears treated in similar fashion with solid medial row anchors.

Short-term outcomes after knotless all-suture anchor Bankart repair

Arthroscopic Bankart repair techniques have evolved from solid anchors, with potential disadvantages such as glenoid rim fractures, anchor migration, and glenohumeral cartilage damage, to bone stock-preserving “soft” all-suture anchors. The aim of this study was to report on clinical short-term outcomes after arthroscopic knotless all-suture Bankart repair in patients with anterior shoulder instability. It is hypothesized that this technique provides good functional outcomes with low rates of re-dislocation and revision. A total of 39 patients with an average age of 28.8 (SD ± 10.5) years were included. The clinical outcome was evaluated at a minimum follow-up of 12 months in 28 of 39 (72%) patients. The American Shoulder and Elbow Surgeons Score (ASES), Single Assessment Numeric Evaluation Score (SANE), Quick Disabilities of the Arm, Shoulder and Hand Score (QuickDASH), the Short Form 12 physical component summary (SF-12 PCS) as well as general patient satisfaction were assessed. Re-dislocation and revision rates were recorded. Postoperatively, one patient (3.6%) re-dislocated his shoulder during a baseball game and required revision surgery with a Latarjet procedure. One patient (3.6%) reported a sensation of instability and 37 of 39 (95%) patients remained stable. At the final follow-up, the mean ASES (p < 0.001), SANE (p < 0.001), QuickDASH (p < 0.001), and SF-12 PCS (p = 0.001) improved significantly over preoperative levels. Median postoperative satisfaction was 10/10 (range 1–10). The arthroscopic treatment of Bankart lesions with a knotless all-suture technique leads to promising clinical short-term results with good function and low rates of re-dislocation and revision. Prospective, randomized, long-term follow-up studies with large patient cohorts are needed in the future.

Biomechanical Comparison of Knotless All-Suture Anchors and Knotted All-Suture Anchors in Type II SLAP Lesions: A Cadaveric Study

To compare the biomechanical performance of knotless versus knotted all-suture anchors for the repair of type II SLAP lesions with a simulated peel-back mechanism. Twenty paired cadaveric shoulders were used. A standardized type II SLAP repair was performed using knotless (group A) or knotted (group B) all-suture anchors. The long head of the biceps (LHB) tendon was loaded in a posterior direction to simulate the peel-back mechanism. Cyclic loading was performed followed by load-to-failure testing. Stiffness, load at 1 and 2 mm of displacement, load to repair failure, load to ultimate failure, and failure modes were assessed. The mean load to repair failure was similar in groups A (179.99 ± 58.42 N) and B (167.83 ± 44.27 N, P= .530). The mean load to ultimate failure was 230 ± 95.93 N in group A and 229.48 ± 78.45 N in group B and did not differ significantly (P= .958). Stiffness (P= .980), as well as load at 1 mm (P= .721) and 2 mm (P= .849) of displacement, did not differ significantly between groups. In 16 of the 20 specimens (7 in group A and 9 in group B), ultimate failure occurred at the proximal LHB tendon. Failed occurred through slippage of the labrum in 1 specimen in each group and through anchor pullout in 2 specimens in group A. Knotless and knotted all-suture anchors displayed high initial fixation strength with no significant differences between groups in type II SLAP lesions. Ultimate failure occurred predominantly as tears of the proximal LHB tendon. All-suture anchors have a smaller diameter than solid anchors, can be inserted through curved guides, preserve bone stock, and facilitate postoperative imaging. There is a paucity of literature investigating the biomechanical capacities of knotless versus knotted all-suture anchors in type II SLAP repair.

Biomechanical Evaluation of Knotless and Knotted All-Suture Anchor Repair Constructs in 4 Bankart Repair Configurations

To evaluate the biomechanical performance of Bankart repair using 1.8-mm knotless all-suture anchors in comparison to 1.8-mm knotted all-suture anchors with both simple and horizontal mattress stitch configurations. Thirty fresh-frozen human cadaveric shoulders were dissected to the capsule, leaving the glenoid and humeral capsular insertions intact. A standardized anteroinferior labral tear was created and repaired using 3 anchors. A 2× 2 factorial design was implemented, with 6 matched pairs randomized between knotless and knotted anchor repairs and 6 matched pairs randomized into simple and horizontal mattress stitch configurations. In addition, 6 unpaired shoulders were used to evaluate the native capsulolabral state. First failure load, ultimate load, and stiffness were assessed. Linear mixed-effects modeling was used to compare endpoints. Digital image correlation was used to evaluate capsular strain throughout testing. Failure modes were reported qualitatively. The knotless all-suture anchor repair showed similar biomechanical strength to the knotted all-suture anchors for first failure load (coefficient, 142 N; 95% confidence interval [CI], -30 to 314 N; P= .12), ultimate load (coefficient, 11.1 N; 95% CI, -104.9 to 127.2 N; P= .847), and stiffness (coefficient, 3.4 N/mm2; 95% CI, -14.1 to 20.9 N/mm2; P= .697) when stitch configuration was held constant. No statistically significant differences were found on comparison of simple and mattress stitch configurations for first failure load (coefficient, -31 N; 95% CI, -205 to 143 N; P= .720), ultimate load (coefficient, 112 N; 95% CI, -321 to 97 N; P=.291), and stiffness (coefficient, -9.6 N/mm2; 95% CI, -27.3 to 8.1 N/mm2; P= .284) when anchor type was held constant. Specimens with knotless anchors and simple stitch techniques resulted in lower stiffness compared with the native state (P= .030). The knotless-mattress configuration resulted in significantly lower strain than the knotted-mattress (P= .037) and knotless-simple (P= .019) configurations and was the only configuration that did not result in a significant increase in strain compared with the intact specimens (P= .216). Fewer instances of suture slippage (loss of loop security) were observed with knotless anchors versus knotted anchors (11% vs 30%), and less soft-tissue failure was observed with the mattress stitch configuration versus the simple stitch configuration (36% vs 47%). Knotless and knotted all-suture anchor repairs with simple and mattress stitch configurations showed similar values of ultimate load, first failure load, and stiffness. However, the horizontal mattress stitch configuration proved to decrease capsular strain more similarly to the native state compared with the simple stitch configuration. Ultimate load and first failure load for all repairs were similar to those of the native state. Knotless all-suture anchors have a smaller diameter than solid anchors, can be inserted through curved guides, and preserve glenoid bone stock. This study presents knotless, tensionable all-suture anchor repair for labral tears that displays high biomechanical fixation strength, similar to the native capsulolabral state.

Optimal Surface Amino-Functionalization Following Thermo-Alkaline Treatment of Nanostructured Silica Adsorbents for Enhanced CO₂ Adsorption.

Special preparation of Santa Barbara Amorphous (SBA)-15, mesoporous silica with highly hexagonal ordered, these materials have been carried out for creating adsorbents exhibiting an enhanced and partially selective adsorption toward CO2. This creation starts from an adequate conditioning of the silica surface, via a thermo-alkaline treatment to increase the population of silanol species on it. CO2 adsorption is only reasonably achieved when the SiO2 surface becomes aminated after put in contact with a solution of an amino alkoxide compound in the right solvent. Unfunctionalized and amine-functionalized substrates were characterized through X-ray diffraction, N2 sorption, Raman spectroscopy, electron microscopy, 29Si solid-state Nuclear Magnetic Resonance (NMR), and NH3 thermal programmed desorption. These analyses proved that the thermo-alkaline procedure desilicates the substrate and eliminates the micropores (without affecting the SBA-15 capillaries), present in the original solid. NMR analysis confirms that the hydroxylated solid anchors more amino functionalizing molecules than the unhydroxylated material. The SBA-15 sample subjected to hydroxylation and amino-functionalization displays a high enthalpy of interaction, a reason why this solid is suitable for a strong deposition of CO2 but with the possibility of observing a low-pressure hysteresis phenomenon. Contrastingly, CH4 adsorption on amino-functionalized, hydroxylated SBA-15 substrates becomes almost five times lower than the CO2 one, thus giving proof of their selectivity toward CO2. Although the amount of retained CO2 is not yet similar to or higher than those determined in other investigations, the methodology herein described is still susceptible to optimization.

Biomechanical Evaluation of Classic Solid and Novel All-Soft Suture Anchors for Glenoid Labral Repair

To evaluate the biomechanical performance of an all-soft suture anchor (JuggerKnot; Biomet, Warsaw, IN) in comparison with a classic solid suture anchor (2.4-mm biocomposite SutureTak; Arthrex, Naples, FL) in an in vitro labral repair model. We dissected 12 cadaveric shoulders (mean age, 61 ± 9.4 years), leaving the labrum intact, and bone mineral density was obtained (mean, 0.375 ± 0.06 g/cm(3)). Simulated labral tears were made at the anteroinferior and posteroinferior edges of the labrum. Repairs used 2 all-soft suture anchors (JuggerKnot) or 2 solid anchors with free, high-strength No. 2 suture (FiberWire; Arthrex) spanning the operative construct to load the repair. Differential variable reluctance transducers were used to measure labral displacement for each specimen. The testing protocol consisted of a preconditioning phase at 10 N for 10 cycles (1 Hz) and then a final load-to-failure testing at a rate of 3 mm/min. Labral displacement of 2 mm was determined as the primary outcome. There was no statistical difference (P = .22) in ultimate load to failure and displacement at ultimate failure (anchor pullout) between the all-soft JuggerKnot (146.0 ± 43.0 N and 19.8 ± 5.4 mm, respectively) and the solid SutureTak (171.9 ± 52.6 N and 22.3 ± 6.8 mm, respectively). The solid anchor had a significantly higher ultimate load at 2 mm of labral displacement than the all-soft suture anchor (84.1 ± 19.0 N and 39.2 ± 10.6 N, respectively; P < .001). Whereas both the solid SutureTak and the all-soft JuggerKnot displayed similar results on ultimate load-to-failure testing, the solid anchor required significantly greater load for 2 mm of labral displacement than the all-soft anchor. The all-soft anchor (JuggerKnot) is similar in biomechanical performance to the classic solid anchor (SutureTak) with the exception of load at 2 mm of labral displacement, suggesting micromotion of the device.

Genipin‐crosslinked microcarriers mediating hepatocellular aggregates formation and functionalities

In engineered regenerative medicine, various types of scaffolds have been customized to pursue the optimal environment for different types of therapeutic cells. In liver therapeutic research, hepatocytes require attachment to solid anchors for survival and proliferation before they could grow into cellular aggregates with enhanced functionalities. Among the various biomaterials scaffolds and vehicles, microspherical cell carriers are suited to these requirements. Individual spheres may provide two-dimensional (2D) cell-affinitive surfaces for cell adhesion and spreading; whereas multiple microcarriers may form three-dimensional (3D) matrices with inter-spherical space for cell expansion and multicellular aggregation. In this study, we culture human liver carcinoma cell line (HepG2) cells on genipin-crosslinked gelatin microspheres of two different sizes. Results suggest that both microcarriers support cell adhesion, proliferation, and spontaneous formation of hepatocellular aggregates, among which the spheres with bigger size (200-300 μm) seem more favorable than the smaller ones in terms of aggregate formation and liver specific functionalities. These findings suggest that the genipin-crosslinked microcarrier is a competent vehicle for liver cell delivery.

Design of New Hybrid Composites using Metal Embedded in Polymer Foam and Foam Composite

Adhesion and loading bearing properties of polyurethane (PU) foams and sandwich composite with metallic inserts are studied. Metal or solid polymer anchors are used as the load transfer components for PU foam and sandwich composites when they are used as the structural element in design. The traditional method of fixation of these components in foams is gluing and fastening. In this work, the anchors are in the form of inserts and are imbedded in the PU during the foaming process. Flexural testing was conducted on PU with and without metallic inserts to establish typical interaction trends. The load-deflection response, mode of failure, and fracture stresses of the PU structures are elucidated. Results show that long taper and leaf inserts imbedded in foam and sandwich composite provide better load carrying capacity. Comparisons between the taper and leaf inserts are documented. Leaf inserts inside a foam and sandwich composite show better results as compared to taper inserts in terms of adhesion and failure stresses. A linear elastic fracture model is also developed for the foam beam, and the fracture toughness is calculated. FEA analyses of the interaction between the inserts and the PU and sandwich composites under different loads were carried out. The FEA modeling results coincide with the experimental ones, hence validating the model.