scholarly journals Knotless Fixation Is Stronger and Less Variable Than Knotted Constructs in Securing a Suture Loop

2018 ◽  
Vol 6 (5) ◽  
pp. 232596711877400 ◽  
Author(s):  
Patrick J. Denard ◽  
Christopher R. Adams ◽  
Nicole C. Fischer ◽  
Marina Piepenbrink ◽  
Coen A. Wijdicks

Background: Historically, tendon-to-bone fixation has relied on knot tying. However, considerable variability exists in knot-tying strength among surgeons. Purpose/Hypothesis: The purpose of this study was to compare the biomechanical properties of knotted and knotless fixation and to evaluate variability among surgeons. The hypothesis was that knotless constructs would be stronger and have less variability as compared with knotted constructs. Study Design: Controlled laboratory study. Methods: A total of 34 orthopaedic surgeons participated in a laboratory study to compare knotted and knotless constructs, where 104 knotted constructs were performed with No. 2 suture, 21 knotless constructs with No. 2 suture (K2 group), and 79 knotless constructs with suture tape (KT group). Mechanical testing was performed to compare load at 3 mm of displacement, load to failure, and stiffness of each construct. Results: The mean load at 3 mm of displacement was greatest in the KT group, with significant differences among all 3 groups ( P < .001). Load to failure was significantly greater in the KT group as compared with the K2 group and the knotted group ( P < .001), but there was no difference between the K2 and knotted groups ( P ≥ .999). Stiffness and displacement were also greatest in the KT group. Based on the F test, the variance in load to failure was significantly different between the knotted and knotless constructs, with the knotted group demonstrating greater variability (SD, 94 N) than the KT (SD, 38 N) and K2 (SD, 17 N) groups ( P < .001). Conclusion: Knotless fixation with suture tape had improved biomechanical performance as compared with knots or knotless fixation with No. 2 suture. In addition, knotless fixation had less variability in biomechanical properties among multiple surgeons. Clinical Relevance: This study may be relevant for surgeons choosing between knotted and knotless constructs as well as for considerations in the design of rotator cuff repair constructs.

2021 ◽  
pp. 036354652110095
Author(s):  
Danko Dan Milinkovic ◽  
Christian Fink ◽  
Christoph Kittl ◽  
Petri Silanpää ◽  
Elmar Herbst ◽  
...  

Background: In contrast to the majority of existing techniques for reconstruction of the medial patellofemoral ligament (MPFL), the technique described in this article uses the adductor magnus muscle tendon to gain a flat, broad graft, leaving its distal femoral insertion intact, and does not require drilling within or near the femoral physis. It also allows for soft tissue patellar fixation and could facilitate anatomic MPFL reconstruction in skeletally immature patients. Purpose: To evaluate the anatomic and structural properties of the native MPFL and the adductor tendon (AT), followed by biomechanical evaluation of the proposed reconstruction. Study Design: Descriptive laboratory study. Methods: The morphological and topographical features of the AT and MPFL were evaluated in 12 fresh-frozen cadaveric knees. The distance between the distal insertion of the AT on the adductor tubercle and the adductor hiatus, as well as the desired length of the graft, was measured to evaluate this graft’s application potential. Load-to-failure tests were performed to determine the biomechanical properties of the proposed reconstruction construct. The construct was placed in a uniaxial testing machine and cyclically loaded 500 times between 5 and 50 N, followed by load to failure, to measure the maximum elongation, stiffness, and maximum load. Results: The mean ± SD length of the AT was 12.6 ± 1.5 cm, and the mean distance between the insertion on the adductor tubercle and adductor hiatus was 10.8 ± 1.3 cm, exceeding the mean desired length of the graft (7.5 ± 0.5 cm) by 3.3 ± 0.7 cm. The distal insertion of the AT was slightly proximal and posterior to the insertion of the MPFL. The maximum elongation after cyclical loading was 1.9 ± 0.4 mm. Ultimately, the mean stiffness and load to failure were 26.2 ± 7.6 N/mm and 169.7 ± 19.2 N, respectively. The AT graft failed at patellar fixation in 2 of the initially tested specimens and at the femoral insertion in the remaining 10. Conclusion: The described reconstruction using the AT has potential for MPFL reconstruction. The AT graft presents a graft of significant volume, beneficial anatomic topography, and adequate tensile properties in comparison with the native MPFL following the data from previously published studies. Clinical Relevance: Given its advantageous anatomic relationship as an application that avoids femoral drilling and osseous patellar fixation, the AT may be considered a graft for MPFL reconstruction in skeletally immature patients.


2021 ◽  
Vol 9 (4) ◽  
pp. 232596712110024
Author(s):  
Koray Şahin ◽  
Fatih Şentürk ◽  
Mehmet Ersin ◽  
Ufuk Arzu ◽  
Mechmet Chodza ◽  
...  

Background: Knot-tying suture-bridge (SB) rotator cuff repair may compromise the vascularity of the repaired tendon, causing tendon strangulation and medial repair failure. The knotless SB repair technique has been proposed to overcome this possibility and decrease retear rates. Purpose: To compare clinical and structural outcomes and retear patterns between the knot-tying and knotless SB techniques. We hypothesized that the knotless technique would result in lower retear rates owing to the preservation of intratendinous vascularity. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 104 patients with full-thickness rotator cuff tears were randomly and prospectively allocated to undergo knot-tying (group 1) or knotless (group 2) SB repair. Clinical outcome measures included range of motion, the visual analog scale (VAS) for pain, and the Constant score for function. Repair integrity was evaluated on magnetic resonance imaging scans using the Sugaya classification. Retears were also classified according to their pattern as type 1 (lateral) or type 2 (medial). Results: Overall, 88 patients (group 1: n = 42 [mean ± SD age, 54.3 ± 9.8 years]; group 2: n = 46 [mean ± SD age, 55.8 ± 8.2 years]) were included in the final analysis. The mean ± SD follow-up period was 25.4 ± 8.3 and 23.3 ± 7.2 months for groups 1 and 2, respectively. From preoperatively to postoperatively, the mean VAS pain score improved significantly in both groups (group 1: from 7.4 ± 1.7 to 1.0 ± 1.7; group 2: from 7.1 ± 1.9 to 1.3 ± 2.0; P < .0001 for both), as did the mean ± SD Constant score (group 1: from 51.7 ± 13.4 to 86.0 ± 11.5; group 2: from 49.4 ± 18.4 to 87.2 ± 14.8; P < .0001 for both). There was no significant difference between the groups for the postoperative VAS or Constant score. The retear rate was not significantly different between the groups (19.0% [8/42] in group 1 and 28.3% [13/46] in group 2; P > .05). There was a significant difference in the type 2 failure rate (75.0% [6/8] in group 1 and 23.1% [3/13] in group 2; P = .03). Conclusion: Both techniques showed excellent improvement and comparable clinical outcomes, and there was no significant difference in retear rates. Consistent with previously published data, the type 2 failure rate was significantly higher with the knot-tying technique. Registration: NCT03982108 ( ClinicalTrials.gov identifier).


2019 ◽  
Vol 7 (4) ◽  
pp. 232596711983826 ◽  
Author(s):  
Frank Martetschläger ◽  
Franziska Reifenschneider ◽  
Nicole Fischer ◽  
Coen A. Wijdicks ◽  
Peter J. Millett ◽  
...  

Background: Despite the rare entity of sternoclavicular joint (SCJ) instability, a variety of different reconstruction techniques for SCJ dislocations have been described. A technique with oblique drilling has been proposed to reduce intraoperative risks. Purpose: To biomechanically investigate different cerclage reconstruction techniques and the benefit of additional reinforcement using suture tape. Study Design: Controlled laboratory study. Methods: Reconstructed artificial bone specimens were mounted on a mechanical testing machine. They were subjected to anterior and posterior translation, analyzing ultimate strength, displacement, stiffness, and elongation. For stage 1, different angulations of the drill tunnels through the sternum and clavicle were compared. Straight drill tunnels from anterior to posterior were compared with 45° oblique drill tunnels. For stage 2, three different materials for cerclage reconstruction were compared: (1) suture tape alone (FT group), (2) tendon graft alone (tendon group), and (3) tendon graft with suture tape augmentation (tendon+FT group). Results: For the FT group, in the anterior and posterior directions, straight drill holes resulted in a significantly higher load to failure (936.9 ± 122.5 N) compared with oblique ones (434.5 ± 20.2 N) ( P < .0001). During cyclic testing, all specimens with straight drill holes survived the 5- to 550-N step, while all specimens with oblique ones failed during the 5- to 450-N step. Analyzing the graft material choice, the mean load to failure was 556.6 ± 174.3 N for the tendon group, 936.9 ± 122.5 N for the FT group, and 767.0 ± 110.7 N for the tendon+FT group ( P = .089). The stiffness of the tendon+FT group was significantly lower than that of the FT group and significantly higher than that of the tendon group. Conclusion: Oblique tunnel placement during SCJ reconstruction, while reducing the intraoperative risk, results in decreased primary stability of the construct. Tendon graft reconstruction with suture tape augmentation leads to enhanced stability and optimizes biomechanical properties of the construct. Clinical Relevance: The surgical technique with straight drill holes has superior initial biomechanical properties and may likewise produce superior clinical outcomes in the treatment of SCJ instability. Suture tape augmentation can provide additional stability to reconstruction procedures.


2021 ◽  
pp. 036354652199831
Author(s):  
Khalis Boksh ◽  
Aziz Haque ◽  
Ashwini Sharma ◽  
Pip Divall ◽  
Harvinder Singh

Background: Various suture materials are available for arthroscopic rotator cuff repair. More recently, suture tapes have become popular as they are perceived to be easier to use with less soft tissue irritation. However, little is known about their biomechanical and clinical properties compared with conventional sutures in rotator cuff repairs. Purpose: To perform a systematic review and meta-analysis on whether suture tapes are biomechanically superior to conventional sutures in arthroscopic rotator cuff repairs and whether this translates to superior functional outcomes and a lower incidence of retears. Study Design: Meta-analysis. Methods: The Cochrane Controlled Register of Trials, PubMed, Medline, and Embase were used to perform a systematic review and meta-analysis using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria with the following search terms: (rotator cuff repair OR arthroscopic rotator cuff repair) AND (“tape” OR “wire” OR “cord” OR “suture”). Data pertaining to certain biomechanical properties (contact area, contact pressure, gap formation, load to failure, and stiffness), retears, and patient-reported outcome measures (PROMs) were extracted. The pooled outcome data were analyzed by random- and fixed-effects models. Results: After abstract and full-text screening, 7 biomechanical and 6 clinical studies were included. All biomechanical studies were on animals, with 91 suture tapes and 91 conventional sutures compared. Suture tapes had higher contact pressure (mean difference [MD], 0.04 MPa; 95% CI, 0.01-0.08; P = .02), higher load to failure (MD, 52.62 N; 95% CI, 27.34-77.90; P < .0001), greater stiffness (MD, 4.47 N/mm; 95% CI, 0.57-8.38; P = .02), and smaller gap formation (MD, −0.30 mm; 95% CI, −0.45 to −0.15; P < .0001) compared with conventional sutures. From the clinical analysis of the 681 rotator cuff repairs treated with a suture tape (n = 380) or conventional suture (n = 301), there were no differences in retear rates between the groups (16% vs 20% suture tape and wire, respectively; P = .26) at a mean of 11.2 months. Qualitatively, there were no differences in PROMs between the groups at a mean of 36.8 months. Conclusion: Although biomechanically superior, suture tapes showed similar retear rates and postoperative function to conventional sutures. However, higher-quality clinical studies are required to investigate whether there are no true differences.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
ZiYing Wu ◽  
Chong Zhang ◽  
Peng Zhang ◽  
TianWu Chen ◽  
ShiYi Chen ◽  
...  

Purpose. To compare the biomechanical properties of 3 suture-bridge techniques for rotator cuff repair. Methods. Twelve pair-matched fresh-frozen shoulder specimens were randomized to 3 groups of different repair types: the medially Knotted Suture Bridge (KSB), the medially Untied Suture Bridge (USB), and the Modified Suture Bridge (MSB). Cyclic loading and load-to-failure test were performed. Parameters of elongation, stiffness, load at failure, and mode of failure were recorded. Results. The MSB technique had the significantly greatest load to failure (515.6±78.0 N, P=0.04 for KSB group; P<0.001 for USB group), stiffness (58.0±10.7 N/mm, P=0.005 for KSB group; P<0.001 for USB group), and lowest elongation (1.49±0.39 mm, P=0.009 for KSB group; P=0.001 for USB group) among 3 groups. The KSB repair had significantly higher ultimate load (443.5±65.0 N) than USB repair (363.5±52.3 N, P=0.024). However, there was no statistical difference in stiffness and elongation between KSB and USB technique (P=0.396 for stiffness and P=0.242 for elongation, resp.). The failure mode for all specimens was suture pulling through the cuff tendon. Conclusions. Our modified suture bridge technique (MSB) may provide enhanced biomechanical properties when compared with medially knotted or knotless repair. Clinical Relevance. Our modified technique may represent a promising alternative in arthroscopic rotator cuff repair.


2008 ◽  
Vol 21 (04) ◽  
pp. 312-317 ◽  
Author(s):  
N. M. M. Moens ◽  
R. J. Runciman ◽  
D. L. Holmberg ◽  
G. M. Monteith ◽  
T. W. G. Gibson

SummaryThe purpose of this study was to determine the biomechanical properties of feline long bone by testing cadaver bone from mature cats in compression, threepoint bending, notch sensitivity and screw pull-out strength. The determination of these properties is of clinical relevance with regard to the forces resulting in long bone fractures in cats as well as the behaviour and failure mode of surgical implants utilized for fracture stabilization and repair in the cat. Cadaveric cat femurs were tested in compression, three-point bending and in three-point bending after the addition of a 2.0 mm screw hole. Cortical screws, 2.7 mm in diameter, were inserted in cadaveric cat femur samples for screw pullout testing. The mean maximum load to failure of mid diaphyseal feline femurs tested in compression was 4201 ± 1218 N. Statistical analysis of the parameter of maximum load tested in compression revealed a statistical difference between sides (p=0.02), but not location (p=0.07), or location by side (p=0.12). The maximum strength of mid diaphyseal feline femurs tested in compression was 110.6 ± 26.6 MPa. The modulus of elasticity of mid-diaphyseal cat femurs tested in compression was determined to be 5.004 ± 0.970 GPa. The mean maximum load to failure of feline femurs tested in three-point bending was 443 ± 98 N. The mean maximum load to failure of feline femurs tested in three-point bending after a 2.0 mm diameter hole was drilled in the mid-diaphyseal region of each sample through both cortices was 471 ± 52 N. The mean maximum load required for screw pull-out of 2.7 mm cortical screws placed in feline femurs tested in tension was 886 ± 221 N. This data should be suitable for investigating fracture biomechanics and the testing of orthopaedic constructs commonly used for fracture stabilization in the feline patient.


2021 ◽  
Vol 9 (5) ◽  
pp. 232596712110060
Author(s):  
Kentaro Ito ◽  
Katsunobu Sakaguchi ◽  
Hirosi Sekihata ◽  
Naoki Sugita ◽  
Yuho Kadono

Background: The self-cinching stitch has been verified to have high mechanical strength. The mechanical strength of combining transosseous rotator cuff repair (RCR) and the self-cinching stitch in the lateral row is unknown. Purpose/Hypothesis: The purpose of this study was to evaluate the biomechanical properties of transosseous RCR combined with the cinch stitch in the lateral row. We hypothesized that this construct would have better mechanical strength than would transosseous repair using a vertical cinch stitch or simple stitch. Study Design: Controlled laboratory study. Methods: Rotator cuff tears were simulated in 48 porcine shoulder specimens. The tears were repaired using 1 of 6 repair configurations: 2–simple stitch transosseous repair alone (group 2TO), with a vertical cinch stitch (group 2TO-VC), or with a horizontal cinch stitch (group 2TO-HC) or 4–simple stitch transosseous repair alone (group 4TO), with a vertical cinch stitch (group 4TO-VC), or with a horizontal cinch stitch (group 4TO-HC). All specimens were set at a 45° angle from the footprint and underwent cyclic loading from 10 to 160 N for 200 cycles, followed by a load-to-failure test at 10 mm/min. Results: During cyclic loading, all specimens in group 2TO and half of the specimens in group 2TO-VC failed by suture pullout. In the other groups, none of the specimens failed before 200 cycles. The yield load in group 2TO-HC was significantly greater than that in group 2TO-VC (261.43 vs 219.54 N, respectively; P < .05). There were significant differences between groups 4TO-HC and 4TO with regard to elongation (3.92 vs 5.68 mm, respectively), yield load (304.04 vs 246.94 N, respectively), and linear stiffness (63.44 vs 52.28 N/mm, respectively) ( P < .01 for all). Group 4TO-HC also had shorter elongation and a superior yield load and linear stiffness compared with group 2TO-HC ( P < .05 for all), and group 4TO-VC had shorter elongation and a stronger maximum load to failure and yield load than did group 2TO-VC ( P < .05 for all). Conclusion: Increasing the number of medial simple stitches can prevent suture pullout. Adding the horizontal cinch stitch to the lateral row in transosseous repair can further improve biomechanical properties through a self-cinching mechanism. Clinical Relevance: Transosseous RCR with a horizontal cinch stitch in the lateral row may reduce the retear rate.


2020 ◽  
Vol 8 (5_suppl4) ◽  
pp. 2325967120S0031
Author(s):  
Danko Dan Milinkovic ◽  
Christian Fink ◽  
Petri Sillanpää ◽  
Michael J. Raschke ◽  
Christoph Kittl ◽  
...  

Aims and Objectives: The main goal of the presented study was to evaluate the anatomical and biomechanical properties of the proposed surgical technique for anatomical Medial Patellofemoral ligament (MPFL) reconstruction using the flat Adductor tendon (AT) graft in order to primarily determine its overall plausibility and application potential, as well as to reveal the main risks and pitfalls of the technique. Materials and Methods: Anatomical descriptive evaluation, followed by biomechanical testing of the proposed AT- MPFL reconstruction was conducted on 12 fresh frozen human cadaveric knees. The morphological and topographical features of the AT and native MPFL were reported. The biomechanical tests were performed in order to determine the strength and resistance to maximum loading force of the reconstruction. The construct was placed in an uniaxial testing machine and cyclically loaded 500 times between 5 and 50N, followed by load to failure, measuring the maximum elongation, stiffness and maximum load respectively. Results: Regarding the anatomical evaluation of the structures in focus, several findings have been reported. The mean length of the tendon was found to be 12,59±1,54cm, the mean distance between the insertion on the Adductor tubercule and Hiatus was measured at 10,83±1,27cm, exceeding the mean desired length of the graft, found at 7,54±0,45cm by 2,43±0,56cm. The desired length of the graft was based on the measured length of the native MPFL with additional ±25-30mm of the tendon that allows for intraoperative length changes and different means of patellar fixation depending on the surgeons preference. The insertion of the Adductor tendon on the Adductor tubercule was found to be superior and posterior to the insertion of the native MPFL. The distal portion of AT was found to be consisted of two distinct parts with varying fiber orientation, the tendinous and the membranous part. After cyclic load, the maximum elongation was reported at 1,9 ± 0,4mm. The mean stiffness and load to failure of the construct were measured at 26,2±7,6N/mm and 148,74±22,01N. The graft failed at the patellar insertion site in two of the tested specimens and at the femoral insertion site in the remaining 10. Conclusion: Due to its advantageous anatomical and topographical aspects, as well as adequate biomechanical properties, the Adductor tendon graft caries a high utilization potential for MPFL reconstruction. Application that allows for primarily soft tissue fixation on the patella, in addition to absence of femoral drill holes with consequently no risk of injury to the physis, makes the AT graft choice a preferable option when considering MPFL reconstruction in patients with open growth plates. Even though it includes graft and methods of fixation alternative to the traditionally used techniques, this reconstruction is not exclusively predetermined for the skeletally immature patients and has a high application potential for the older patient population as well.


2017 ◽  
Vol 45 (9) ◽  
pp. 2028-2033 ◽  
Author(s):  
Christine Conroy ◽  
Paul Sethi ◽  
Craig Macken ◽  
David Wei ◽  
Marc Kowalsky ◽  
...  

Background: The majority of distal biceps tendon injuries can be repaired in a single procedure. In contrast, complete chronic tears with severe tendon substance deficiency and retraction often require tendon graft augmentation. In cases with extensive partial tears of the distal biceps, a human dermal allograft may be used as an alternative to restore tendon thickness and biomechanical integrity. Hypothesis: Dermal graft augmentation will improve load to failure compared with nonaugmented repair in a tendon-deficient model. Study Design: Controlled laboratory study. Methods: Thirty-six matched specimens were organized into 1 of 4 groups: native tendon, native tendon with dermal graft augmentation, tendon with an attritional defect, and tendon with an attritional defect repaired with a graft. To mimic a chronic attritional biceps lesion, a defect was created by a complete tear, leaving 30% of the tendon’s width intact. The repair technique in all groups consisted of cortical button and interference screw fixation. All specimens underwent cyclical loading for 3000 cycles and were then tested to failure; gap formation and peak load at failure were documented. Results: The mean (±SD) load to failure (320.9 ± 49.1 N vs 348.8 ± 77.6 N, respectively; P = .38) and gap formation (displacement) (1.8 ± 1.4 mm vs 1.6 ± 1.1 mm, respectively; P = .38) did not differ between the native tendon groups with and without graft augmentation. In the tendon-deficient model, the mean load to failure was significantly improved with graft augmentation compared with no graft augmentation (282.1 ± 83.8 N vs 199.7 ± 45.5 N, respectively; P = .04), while the mean gap formation was significantly reduced (1.2 ± 1.0 mm vs 2.7 ± 1.4 mm, respectively; P = .04). The mean load to failure of the deficient tendon with graft augmentation (282.1 N) compared with the native tendon (348.8 N) was not significantly different ( P = .12). This indicates that the native tendon did not perform differently from the grafted deficient tendon. Conclusion: In a tendon-deficient, complete distal biceps rupture model, acellular dermal allograft augmentation restored the native tendon’s biomechanical properties at time zero. The grafted tissue-deficient model demonstrated no significant differences in the load to failure and gap formation compared with the native tendon. As expected, dermal augmentation of attritional tendon repair increased the load to failure and stiffness as well as decreased displacement compared with the ungrafted tissue-deficient model. Tendons with their native width showed no statistical difference or negative biomechanical consequences of dermal augmentation. Clinical Relevance: Dermal augmentation of the distal biceps is a biomechanically feasible option for patients with an attritionally thinned-out tendon.


2017 ◽  
Vol 5 (5) ◽  
pp. 232596711770830 ◽  
Author(s):  
Matthew A. Dorweiler ◽  
Rufus O. Van Dyke ◽  
Robert C. Siska ◽  
Michael A. Boin ◽  
Mathew J. DiPaola

Background: Triceps tendon ruptures are rare orthopaedic injuries that almost always require surgical repair. This study tests the biomechanical properties of an original anchorless double-row triceps repair against a previously reported knotless double-row repair. Hypothesis: The anchorless double-row triceps repair technique will yield similar biomechanical properties when compared with the knotless double-row repair technique. Study Design: Controlled laboratory study. Methods: Eighteen cadaver arms were randomized into 2 groups. One group received the anchorless repair and the other received the knotless anchor repair. A materials testing system (MTS) machine was used to cycle the repaired arms from 0° to 90° with a 2.5-pound weight for 1500 cycles at 0.25 Hz. Real-time displacement of the tendon was measured during cycling using a probe. Load to failure was performed after completion of cyclic loading. Results: The mean displacement with the anchorless technique was 0.77 mm (SD, 0.25 mm) at 0° (full elbow extension) and 0.76 mm (SD, 0.38 mm) at 90° (elbow flexion). The mean displacement with the anchored technique was 0.83 mm (SD, 0.57 mm) at 0° and 1.01 mm (SD, 0.62 mm) at 90°. There was no statistically significant difference for tendon displacement at 0º ( P = .75) or 90º ( P = .31). The mean load to failure with the anchorless technique was 618.9 N (SD, 185.6 N), while it was 560.5 N (SD, 154.1 N) with the anchored technique, again with no statistically significant difference ( P = .28). Conclusion: Our anchorless double-row triceps repair technique yields comparable biomechanical properties to previously described double-row triceps tendon repair techniques, with the added benefit of avoiding the cost of suture anchors. Clinical Relevance: This anchorless double-row triceps tendon repair can be considered as an acceptable alternative to a knotless anchor repair for triceps tendon ruptures.


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