Ultra-high Molecular Weight Polyethylene Suture Research Articles

Comparison of Suture Types and Techniques in Achilles Tendon Repair: An Ex Vivo Biomechanical Animal Experiment.

The ideal suture technique and type in tendon repair remain unclear. This biomechanical study aimed to assess the biomechanical characteristics of three techniques-modified Kessler (mKE), modified Krackow (mKR), and modified tension Bunnell (mtBU)-in sheep Achilles tendon tear repair using three suture types-polypropylene, polyester, and ultra-high-molecular-weight polyethylene (UHMWPE)-which are also compared. Sixty-three Achilles tendons harvested from sheep were transversely hacked as a replacement for rupture in a standardized measure and repaired using mKE, mKR, and mtBU techniques with No. 2 polypropylene, polyester, and UHMWPE sutures. Biomechanical parameters, such as Young's modulus, ultimate strength, and strength to the 5-mm gap, were recorded for statistical analysis. The mtBU technique with UHMWPE use resulted in increased ultimate strength, strength to 5-mm gap, Young's modulus, and quantity of specimens with low clinical failure modes compared with the other techniques with other suture materials. Furthermore, mtBU has the lowest thickness at the repair side of the tendons. This approach showed tendon failure during maximal traction testing, whereas the mKE and mKR techniques had polyethylene and polyester suture failures. The UHMWPE suture was significantly superior to the other sutures in each technique in terms of strength and durability. The mtBU technique using UHMWPE suture showed better biomechanical results, implying that this repair might be more appropriate to obtain early mobilization after tendon ruptures.

Seatbelt Anterior Cruciate Ligament Reconstruction: A Variant of Internal Brace in Anterior Cruciate Ligament Reconstruction With an Adjustable Loop

In recent years, there has been a growing interest in primary anterior cruciate ligament repair with the help of mechanical reinforcement techniques that employ synthetic grafting. The concept of ligament augmentation with reinforcement suture or internal bracing consists of stabilizing the repaired ligament and augmenting it with an ultra-high molecular weight polyethylene suture or tape, which guarantees greater resistance, safety during healing, and a more accelerated rehabilitation. In this work, we propose a variant of anterior cruciate ligament augmentation with suture, replacing the suture tape with an adjustable-loop reinforcement system, which is connected to the adjustable suspension devices for the graft in the femur and the tibia, surrounding the graft as a seatbelt.

Anatomical Double-Bundle Anterior Cruciate Ligament Reconstruction With Suture Augmentation

Ultra-high molecular weight polyethylene sutures are used for repair and reconstruction of extra-articular ligaments in the knee, elbow, and ankle joints. In recent years, the use of these sutures has become popular in a suture augmentation technique and has been applied for use in the reconstruction of the anterior cruciate ligament, which is an intra-articular ligament. Although several surgical techniques have been described in Technical Notes, all reports have been for single-bundle reconstruction, and none have applied the technique to double-bundle reconstruction. This Technical Note provides a detailed description of an anatomical double-bundle anterior cruciate ligament reconstruction combined with the suture augmentation technique.

Successful Management of Congenital Radial Head Subluxation in a Juvenile Dog Using Ultra-High Molecular Weight Polyethylene Suture Toggle

AbstractCongenital humeroradial subluxation was diagnosed by clinical examination and radiography in a 16-week-old female dog that presented for left forelimb lameness. This was treated surgically by open reduction followed by placement of an ultra-high molecular weight polyethylene suture from the craniolateral aspect of the proximal radius to the caudomedial aspect of the ulna, secured with a toggle and suture button. Postoperative findings were consistent with clinical improvement and radiographs were compatible with resolution of elbow subluxation. To our knowledge, this is the first case report of congenital humeroradial subluxation to be managed with an ultra-high molecular weight polyethylene suture toggle.

A 3-Dimensional Suture Technique for Flexor Tendon Repair: A Biomechanical Study

Flexor tendon injury continues to pose a number of challenges for hand surgeons. Improving mechanical properties of repairs should allow for earlier and unprotected rehabilitation. A 3-dimensional (3D) 4-strand suture technique has been proposed to combine high tensile strength and low gliding resistance without causing suture pullout due to tendon delamination. Our hypothesis is that the 3D technique can result in better mechanical properties than the Adelaide technique. Four groups of 10 porcine flexor tendons were sutured using the 3D or Adelaide technique with a 3-0 polypropylene or ultrahigh molecular weight polyethylene (UHMWPE) suture. The axial traction test to failure was performed on each tendon to measure 2-mm gap force and ultimate tensile strength. The mean 2-mm gap force was 49 N for group A (3D+ polypropylene), 145 N for group B (3D+ UHMWPE), 47 N for group C (Adelaide+ polypropylene), and 80 N for group D (Adelaide+ UHMWPE). Failure mode was caused by suture breakage for group A (10/10) and mainly by suture pullout for the other groups (8/10 up to 10/10). With the UHMWPE suture, the mean ultimate tensile strength was 145 N for the 3D technique and 80 N for the Adelaide technique. Porcine flexor tendons repaired using the 3D technique and UHMWPE suture exceeded a 2-mm gap force and tensile strength of 140 N. The ultimate tensile strength was superior to that of the Adelaide technique, regardless of the suture material. This invitro study on porcine flexor tendon suture highlights that the mechanical properties of 3D repair are better than those of 3D repair using the Adelaide technique when a UHMWPE suture is used.

Whether sutures reduce the graft laceration caused by interference screw in anterior cruciate ligament reconstruction? A biomechanical study in vitro

BackgroundInterference screw is commonly used for graft fixation in anterior cruciate ligament (ACL) reconstruction. However, previous studies had reported that the insertion of interference screws significantly caused graft laceration. The purposes of this study were to (1) quantitatively evaluate the graft laceration from one single insertion of PEEK interference screws; and (2) determine whether different types of sutures reduced the graft laceration after one single insertion of interference screws in ACL reconstruction.MethodsThe in-vitro ACL reconstruction model was created using porcine tibias and bovine extensor digitorum tendons of bovine hind limbs. The ends of grafts were sutured using three different sutures, including the bioabsorbable, Ethibond and ultra-high molecular weight polyethylene (UHMWPE) sutures. Poly-ether-ether-ketone (PEEK) interference screws were used for tibial fixation. This study was divided into five groups (n = 10 in each group): the non-fixed group, the non-sutured group, the absorbable suture group, the Ethibond suture group and the UHMWPE suture group. Biomechanical tests were performed using the mode of pull-to-failure loading tests at 10 mm/min. Tensile stiffness (newtons per millimeter), energy absorbed to failure (in joules) and ultimate load (newtons) were recorded for analysis.ResultsAll prepared tendons and bone specimens showed similar characteristics (length, weight, and pre-tension of the tendons, tibial bone mineral density) among all groups (P > 0.05). The biomechanical tests demonstrated that PEEK interference screws significantly caused the graft laceration (P < 0.05). However, all sutures (the bioabsorbable, Ethibond and UHMWPE sutures) did not reduce the graft laceration in ACL reconstruction (P > 0.05).ConclusionsOur biomechanical study suggested that the ultimate failure load of grafts was reduced of approximately 25 % after one single insertion of a PEEK interference screw in ACL reconstruction. Suturing the ends of the grafts using different sutures (absorbable, Ethibond and UHMWPE sutures) did not decrease the graft laceration caused by interference screws.

Arthroscopic Fixation of Anterior Cruciate Ligament Avulsion Fracture Using FiberWire Suture With Suture Disc

Controversy still exists regarding how to reduce and fix a displaced tibial avulsion fracture. Open reduction and internal fixation may lead to morbidity due to soft-tissue injury and arthrotomy. As a result, arthroscopic techniques are increasing in popularity. In the literature, sutures, K wires, and screws are suggested to be used as the fixation devices. Screws cannot be used in small or comminuted fractures, whereas K wires and sutures may not provide strong stability. Recently, with the advent of ultrahigh molecular weight polyethylene sutures like FiberWire, it has become possible to use it as the fixation device in even comminuted avulsion fractures with acceptable reduction stability. In this paper, we describe a simple arthroscopic technique using a FiberWire to manage the displaced tibial eminence avulsion fracture.

Biomechanical Comparisons of Anterior Cruciate Ligament Avulsion Fracture Fixation Using High-Strength Suture and Ultra-High Molecular Weight Polyethylene Suture Tape in a Porcine Model.

A wide variety of fixation methods have been reported to fix anterior cruciate ligament (ACL) tibial avulsion fractures, but there have been no studies into the fixation of these fractures with ultra-high molecular weight polyethylene (UHMWPE) suture tape as an alternative to conventional thread. Type III ACL tibial avulsion fractures were created in 20 skeletally immature porcine knees. All specimens were randomized into two treatment groups: (1) pullout repair using no. 2 suture fixation and (2) pullout repair using UHMWPE suture tape fixation. The specimens were tested cyclically (20 cycles, 0-40 N, 100 mm/min) in the direction of the native ACL and loaded to failure (100 mm/min) on a tensile tester. Statistically significant differences between the structural properties (displacement, upper yield load, maximum load, linear stiffness, and elongation at failure) under cyclic loading and single-cycle loading were analyzed. Displacement during cyclic testing was 1.56 ± 1.03 mm in the UltraBraid group and 0.99 ± 0.48 mm in the SUTURETAPE group, with no significant differences found between the groups (p = 0.13). There were no significant differences in upper yield load (161.9 ± 68.9 N in the UltraBraid group, 210.4 ± 60.1 N in the SUTURETAPE group, p = 0.11), linear stiffness (14.7 ± 4.7N/mm in the UltraBraid group, 18.1 ± 7.9 N/mm in the SUTURETAPE group, p = 0.27), or elongation at failure (20.1 ± 8.0 mm in the UltraBraid group, 21.5 ± 7.2 mm in the SUTURETAPE group, p = 0.69). On the other hand, significant differences were observed in maximum load in the SUTURETAPE group (219.7 ± 89.2 N in the UltraBraid group, 319.3 ± 92.6 N in the SUTURETAPE group, p = 0.025).

Biomechanical Comparison of Tape Versus Suture in Simulated Achilles Tendon Midsubstance Rupture

As sutures have progressed in strength, increasing evidence supports the suture tendon interface as the site where most tendon repairs fail. We hypothesized that suture tape would have a higher load to failure versus polyblend suture due to its larger surface area. Eleven matched pairs of cadaveric Achilles tendons were sutured with 2 mm wide braided ultrahigh molecular weight polyethylene tape (Tape) or 2 mm wide braided ultrahigh molecular weight polyethylene suture (Suture) using a Krackow repair method. All Achilles repair constructs were cyclically loaded, after which they were loaded to failure. Change in suture footprint height, clinical and ultimate load to failure, and location of failure was recorded. Clinical loads to failure for Tape and Suture were 290.4 ± 74.8 and 231.7 ± 70.4 Newtons, respectively (p= .01). Ultimate loads to failure for Tape and Suture were 352.9 ± 108.1 and 289.8 ± 53.7 Newtons, respectively (p = .11). Cyclic testing resulted in significant changes in footprint height for both Tape and Suture, but the 2 sutures did not differ in terms of the magnitude of change in footprint height (p = .52). The suture tendon interface was the most common site of failure for both Tape and Suture. Our results suggest that Tape may provide added repair strength in vivo for Achilles midsubstance rupture.

Modified Circumcostal Suture Stabilization of Scapular Avulsion in a Maine Coon Cat

AbstractThis study describes the surgical management of a traumatic scapular avulsion including complications and clinical outcome in a 3-year-old Maine Coon cat. Traumatic scapular avulsion was diagnosed clinically and confirmed on a computed tomography scan, alongside severe scapula displacement. The scapula was stabilized surgically by the placement of two circumcostal sutures, through paired bone tunnels drilled both cranial and caudal to the base of the scapular spine, and two sutures passing through bone tunnels in the dorsal border of the scapula bone secured to the serratus ventralis muscle. The cat was able to bear weight on the affected limb within 48 hours of surgery; however, limb function subsequently deteriorated at home. Revision surgery was required 14 days postoperatively to replace failed polydioxanone suture with ultra-high molecular weight polyethylene suture (Fiberwire). Following revision surgery, the cat had a very acceptable functional outcome, with scapular stability and only intermittent lameness/stiffness noted in the medium-term follow-up. The present case report demonstrates that the described modified surgical technique may be used successfully in the treatment of scapular avulsion in cats and restores acceptable function to the affected limb.

Continuous Loop Double Cortical Button Technique for Distal Tibiofibular Syndesmosis Stabilization: A Technical Note and Case Series

Injury to the distal tibiofibular syndesmosis is common and failure to correct instability may lead to inferior outcomes. Recently, suture-button devices have garnered increasing attention for dynamic syndesmotic fixation. However, current constructs and techniques have been consistently associated with complications such as lateral knot irritation and wound breakdown. In addition, knot slippage, loosening, and osteolysis have been described leading to recurrent syndesmotic diastasis. To address these shortcomings, a continuous loop double cortical button technique has been developed for dynamic syndesmotic stabilization. The continuous loop double cortical button technique has been utilized for coracoclavicular ligament stabilization for both acromioclavicular joint dislocation and distal clavicle fractures with excellent clinical outcomes. This procedure has been adapted for fixation of the distal tibiofibular syndesmosis. The technique utilizes 2 cortical buttons linked by a continuous loop of ultra-high molecular weight polyethylene suture for dynamic knotless syndesmotic fixation. The continuous loop double cortical button technique was performed on 4 consecutive cases of distal tibiofibular syndesmosis diastasis. Accurate, stable fixation was achieved in all cases without loosening or diastasis. At the final follow-up, no evidence of button-related osteolysis or migration was observed. One patient with prominent lateral hardware developed a wound infection requiring reoperation for hardware removal and debridement. Otherwise, no complications related to syndesmotic hardware were observed. The continuous loop double cortical button technique is a reproducible and reliable procedure for fixation of the distal tibiofibular syndesmosis. The construct allows for accurate restoration of the dynamic syndesmotic complex without compromising stability. Knot-related complications are minimized. As with all systems, limiting lateral hardware prominence appears to reduce the risk of wound-related complications. Level of Evidence: Diagnostic Level IV—case series. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical comparison of four prosthetic ligament repair techniques for tarsal medial collateral ligament injury in dogs

To compare joint stability and ultimate strength among 4 prosthetic ligament constructs for repair of tarsal medial collateral ligament (MCL) injury in dogs. 13 canine cadavers (26 hind limbs). Each limb was stripped of all soft tissues except those associated with the tarsal joint and assigned to 1 of 4 prosthetic ligament constructs. The AN construct consisted of 3 bone anchors connected with monofilament nylon suture. The AU construct consisted of low-profile suture anchors connected with multifilament ultrahigh-molecular-weight polyethylene (UHMWPE) suture. The TN and TU constructs involved the creation of 3 bone tunnels and use of nylon or UHMWPE suture, respectively. Each limb underwent biomechanical testing before and after MCL transection and before and after cyclic range-of-motion testing following completion of the assigned construct. Tarsal joint stability (extent of laxity) was assessed with the joint in each of 3 positions (75°, 135°, and 165°). After completion of biomechanical testing, each limb was tested to failure to determine the ultimate strength of the construct. Relative to intact tarsal joints, joint laxity was significantly increased following completion of all 4 constructs. Construct type was not associated with the magnitude of change in joint laxity. Ultimate strength was greatest for the UHMWPE-suture constructs. Results indicated that all 4 constructs effectively stabilized MCL-deficient tarsal joints. Implants used for the TU, TN, and AU constructs had a lower profile than those used for the AN construct, which may be clinically advantageous. In vivo studies are warranted.

A Retrospective Evaluation of Anatomical Reinsertion of the Distal Biceps Brachii Tendon Using an ACL TightRope® RT with a Titanium Cortical Button and Ultra High Molecular Weight Polyethylene Suture: A Preliminary Report.

Various surgical techniques for treating distal biceps brachii tendon injury have been described, and to date there is no consensus regarding the preferred fixation method for the anatomic reinsertion of the ruptured tendon. The aim of the study was to clinically and functionally evaluate the upper limb after surgical anatomic reinsertion of the distal biceps brachii tendon using an ACL TightRope® RT with a titanium cortical button and ultra high molecular weight polyethylene (UHMWPE) suture, and to assess postoperative complications. The sample comprised 3 patients. Clinical examination (history, measurements of the active range of forearm motion, arm circumference, the maximum isometric forearm supination and flexion muscle torque), pain evaluation (on a visual analogue scale [VAS]) and functional assessment (the Mayo Elbow Performance Index [MEPI] and Quick Disabilities of the Arm, Shoulder and Hand [DASH]) were carried out. Complications were documented. The results of the range of motion measurements, arm circumferences and normalized isometric torque values of the muscle groups being studied were comparable in the involved and uninvolved limbs. The MEPI (x = 95.00 ± 10.42) and Quick DASH (x = 8.66 ± 18.04) scores revealed very good results. The VAS results were close to no pain (x = 3.33 ± 5.77 mm). No complications were noted. The preliminary comprehensive clinical and functional assessment of the upper limb justify the clinical use of the ACL TightRope® RT with a titanium cortical button and UHMWPE suture in surgical anatomic reinsertion of the distal biceps brachii tendon. The early results with a small sample were encouraging, but studies with a larger number of cases and longer follow-up are needed.

Effect of Participation in an Arthroscopic Training Course on Arthroscopic Knot Tying Skills in Orthopaedic Residents

The purpose of this study is to assess improvement in speed and strength of arthroscopically tied knots after completion of an arthroscopic resident training course. Our hypothesis is that focused instruction will lead to improvement in speed and strength of residents' arthroscopically tied knots. After IRB approval, 64 participants (8 PGY-3 and 8 PGY-4 residents annually for 4 years) were enrolled and completed a two year, five day per year training course with a single attending arthroscopic surgeon. Outcomes were measured before and after completion of the course on 5 knots per participant using ultra-high molecular weight polyethylene suture and a ring knot pusher via a standard 8mm arthroscopic cannula on an arthroscopic knot tying station. Time per knot was measured and recorded in seconds. Knots were then preloaded, cycled, and tested for mode of failure, and ultimate peak load to failure in newtons, on a material testing machine. Mean change in ultimate load per knot per participant was compared pre- and post-training. Statistical analysis was performed using a two-tailed paired t-test. Average post-test peak load to failure (139.23N, S.D. 51.35N) was not significantly different from pre-test (136.05N, S.D. 61.5N (p = 0.7). Mean time to complete 5 knots was significantly faster after training 12.77 minutes versus 9.39 minutes (p < 0.0001). Our primary result is that participation in an arthroscopic skills course improves resident speed in tying arthroscopic knots. Our data did not demonstrate a significant change in knot load to failure with training. Limitations are that study subjects are orthopaedic residents who participated in training and testing annually for 2 years. Clinical relevance is that residents who practice arthroscopic knot tying 5 days per year for 2 years can save time in the operating room.

Biomechanical Evaluation of Physeal-Sparing Fixation Methods in Tibial Eminence Fractures

Background: Tibial eminence fractures occur most commonly in skeletally immature children. Several techniques using physeal-sparing fracture fixation have been described, but their structural properties have not been evaluated. Purpose: To determine the strength and resistance to displacement of physeal-sparing techniques used to fix tibial eminence fractures. Study Design: Controlled laboratory study. Methods: Skeletally immature porcine knees were randomized into 4 treatment groups: (1) ultra–high molecular weight polyethylene suture–suture button (UHMWPE/SB), (2) suture anchor, (3) polydioxanone suture–suture button (PDS/SB), and (4) screw fixation. A prospective analysis of bone mineral density using dual-energy x-ray absorptiometry was performed on all specimens. Fracture fragments were created in a standardized manner and measured for size comparison. After fracture fixation, biomechanical testing was performed with cyclical and load-to-failure protocols by loading the tibia with an anterior shear force. Results: In load-to-failure testing, screw fixation had a significantly lower median peak failure load (186.4 N; lower quartile [LQ], 158.4 N; upper quartile [UQ], 232.6 N) than did UHMWPE/SB (465.8 N; LQ, 397.8 N; UQ, 527.8 N), suture anchors (440.5 N; LQ, 323.0 N; UQ, 562.3 N), and PDS/SB (404.3 N; LQ, 385.9 N; UQ, 415.6 N). UHMWPE/SB demonstrated a significantly higher median yield load (465.8 N; LQ, 397.8 N; UQ, 527.8 N) than did PDS/SB (306.7 N; LQ, 271.4, N; UQ, 405.7 N) and screw fixation (179.0 N; LQ, 120.2 N; UQ, 232.5 N). During cyclical testing, screw fixation demonstrated significantly lower percentage survival of specimens (0%) compared with the other groups (UHMWPE/SB, 100%; suture anchor, 78%; PDS/SB, 78%). After 1000 cycles of loading, PDS/SB fixation had significantly more median creep (6.76 mm; LQ, 6.34 mm; UQ, 8.28 mm) than did UHMWPE/SB (4.43 mm; LQ, 3.80 mm; UQ, 4.73 mm) and suture anchor fixation (3.06 mm; LQ, 2.59 mm; UQ, 4.28 mm). The lowest median stiffness was observed in the PDS/SB group (48.6 N/mm; LQ, 45.3 N/mm; UQ, 54.2 N/mm). UHMWPE/SB fixation demonstrated a significantly higher median peak failure load after cyclic testing (469.0 N; LQ, 380.6 N; UQ, 507.2 N) than did PDS/SB (237.7 N; LQ, 197.3 N; UQ, 298.3 N) and screw fixation (132.4 N; LQ, 123.7 N; UQ, 180.9 N). Suture anchor fixation had significantly more variance, as demonstrated by width of interquartile range, in peak failure load, yield load, and creep than did other techniques. Conclusion: Physeal-sparing fixation of tibial eminence fractures with UHMWPE suture–suture button is biomechanically superior to both PDS suture–suture button and a single screw at the time of surgery and provides more consistent fixation than do suture anchors. Clinical Relevance: Suture anchors provide inconsistent fixation for tibial eminence fractures.

Repair of Peripheral Vertical Meniscus Lesions in Porcine Menisci

Background: All-inside meniscus repair eliminates the need for an extra incision and decreases neurovascular injury risk. Biomechanical testing can help delineate the efficacy of all-inside device use. Hypothesis: There would be no group differences between 4 peripheral meniscus repair techniques and 3 different devices tested. Study Design: Controlled laboratory study. Methods: Equivalent-sized menisci with attached tibiae were randomly assigned to 1 of 4 test groups (8 specimens each), as follows: group 1, Fast-Fix using No. 0 braided polyester suture; group 2, inside-out repair using 2-0 braided polyester suture; group 3, Sequent using No. 0 ultra–high molecular weight polyethylene (UHMWPE) suture in a continuous “N” configuration; and group 4, Sequent using No. 0 UHMWPE suture in an interrupted configuration. After placement in a clamp, specimens underwent preconditioning from 5 to 20 N for 10 cycles (0.1 Hz), 500 submaximal loading cycles from 5 to 20 N (0.5 Hz), and load-to-failure testing at 12.5 mm/s. A 30-second pause after 10 preconditioning cycles and after 10, 100, and 500 submaximal loading cycles enabled digital photographs to be taken for gapping measurements. Failure mode was recorded. Results: Specimens in group 3 withstood greater failure loads than did those in groups 1 and 4 (P ≤ .027), and group 3 specimens were stiffer than those in groups 2 and 4 (P ≤ .048). Displacement during submaximal loading and load-to-failure testing did not differ between groups. Groups 1, 3, and 4 each gapped less than group 2 during submaximal cyclic loading (P ≤ .05). Groups 1 and 2 failed primarily by suture breakage (P < .0001), while groups 3 and 4 failed primarily by the suture pulling free from an implant (P < .0001). Conclusion: Sequent using No. 0 UHMWPE suture in a continuous “N” configuration displayed superior load at failure compared with repairs using Fast-Fix with No. 0 braided polyester suture and displayed greater stiffness and less gapping than inside-out repair using 2-0 braided polyester suture. The suture pulling free from an implant was the primary failure mode for Sequent using No. 0 UHMWPE suture regardless of whether a continuous “N” or an interrupted configuration was used. Study groups that used No. 0 UHMWPE sutures (groups 3 and 4) had more specimens fail by the suture pulling free from an implant. Compared with the weaker braided polyester suture in the inside-out and Fast-Fix groups, the No. 0 UHMWPE suture used in the Sequent groups likely influenced study results, as this suture has stronger material properties. However, the continuous “N” configuration likely also improved the performance of the Sequent with No. 0 UHMWPE suture, as failure load was significantly less with an interrupted configuration. Clinical Relevance: All-inside meniscus repair with continuous suture function may translate into improved patient outcomes.

The influence of suture material on the strength of horizontal mattress suture configuration for meniscus repair

PurposeComparison of the mechanical characteristics of meniscal repair fixation using horizontal sutures and six different sutures under submaximal cyclic and load to failure test conditions may aid physicians in selecting a suture type. MethodsA 2-cm long anteroposterior vertical longitudinal incision was created in six groups of bovine medial menisci. Lesions were repaired using a No. 2 suture either composed of polyester or polyester and ultra high-molecular weight polyethylene (UHMWPE), or UHMWPE and polydioxanone or pure UHMWPE. Endpoints included ultimate failure load (N), pull-out stiffness (N/mm), pull-out displacement (mm), cyclic displacement (mm) after 100cycles, after 500cycles, and mode of failure. ResultsPolyester suture had lower ultimate load than all groups except the suture composed of polyester and UHMWPE (P<.05). Pure UHMWPE suture had higher ultimate failure load than sutures composed of either polyester or polyester plus UHMWPE (P<.05).Predominant failure mode was suture cutting through the meniscus for the groups except for polyester suture which failed by suture rupture. ConclusionUnder cyclic loading conditions in bovine meniscus, braided polyester suture fixation provided lower initial fixation strength than fixation with various high strength sutures composed of pure UHMWPE or a combination of absorbable monofilament polydioxanone and UHMWPE, except for combination of polyester and UHMWPE sutures. Clinical relevancePresent study does not support the usage of the braided polyester sutures instead of high strength sutures composed either partially or totally of ultra-high molecular weight polyethylene for the horizontal suture configuration of meniscus repair.

Influence of Testing Conditions on Primary Stability of Arthroscopic Knot Tying for Rotator Cuff Repair: Slippery When Wet?

The purpose was to evaluate whether the knot security of sliding and nonsliding knots with different sutures is influenced by dry or wet conditions. We tested 5 suture materials, all of them US Pharmacopeia No. 2: PDS (polydioxanone) II (Ethicon, Somerville, NJ), Ethibond (Ethicon), and 3 ultrahigh-molecular weight polyethylene (UHMWPE) sutures-FiberWire (Arthrex, Naples, FL), Orthocord (DePuy Mitek, Raynham, MA), and Herculine (Linvatec, Largo, FL). Testing was performed under dry and wet conditions with sutures soaked in a saline solution. Cyclic loading was performed to simulate physiologic conditions. We started with a tensile load of 25 N. After 100 cycles, the load was increased to 50 N for another 100 cycles. The tensile load was gradually increased by 25 N per 100 cycles until suture rupture or knot slippage, defined as lengthening over 3 mm. Under dry conditions, 170 suture ruptures and 30 knot slippages were reported; and under wet testing conditions, 186 suture ruptures and 14 knot slippages were reported, with P < .044 and P < .027, respectively. Failure by knot slippage (n = 44) was seen under dry and saline solution conditions mainly with UHMWPE sutures, in particular with the Herculine suture using a Roeder knot showing comparable maximum failure loads in dry (274.5 ± 58.2 N) and saline solution (312.5 ± 14.2 N) conditions (P > .056). Knot slippage occurred only with sliding knots. With the Ethibond suture, no knot slippage was found regardless of the testing conditions and knot type. Across all knot types, the UHMWPE sutures were significantly stronger with respect to clinical and maximum failure loads in ultimate load to failure than Ethibond and PDS II under dry and wet testing conditions (P < .001 for both). We conclude that testing of different suture materials and knot types is different in wet versus dry conditions and believe that biomechanical testing might be more realistic in a wet environment. Suture knots behave differently in a wet versus dry environment, and testing of knot mechanics might better be carried out in wet environments.

Treatment of a Coxofemoral Luxation in a Pony Using a Prosthetic Capsule Technique

To report open reduction and joint stabilization using a prosthetic capsule technique for treatment of a craniodorsal coxofemoral luxation in a lightweight pony. Clinical report. Pony stallion (8 years old, 113 kg). A craniodorsal approach to the coxofemoral joint was performed under general anesthesia. After open reduction, a prosthetic capsule technique was used. Four 3.5 mm self-tapping cortical anchor screws were implanted: 2 screws were inserted above the cranial aspect of the dorsal acetabular rim, and 2 screws were inserted into the femoral neck. Subsequently, a #5 USP ultra-high molecular weight polyethylene suture was placed through these anchor screws in figure-8 fashion to serve as a prosthetic capsule. Routine closure and a medial patellar desmotomy completed the surgical procedure. Postoperatively, the pony was cross tied for 4 weeks to prevent it from lying down. Neither short-term nor long-term complications occurred and the pony was sound at the follow-up examination performed 15 months postoperatively. A prosthetic capsule technique can be used successfully to stabilize the coxofemoral joint after open reduction of a craniodorsal luxation in a lightweight pony.

EFFECT OF A NEW REPAIR TECHNIQUE ON BIOMECHANICAL PROPERTIES OF CANINE FLEXOR TENDONS — IN VITRO STUDY

A new repair technique that was easy to perform yet offered adequate strength was developed. The purpose of this study was to evaluate the mechanical properties of flexor tendon repairs undertaken with this technique. Thirty-two canine cadaver flexor digitorum profundus tendons in Zone 2 were lacerated and repaired with the technique, which consisted of a four-strand core suture using the double-modified Kessler method in combination with a cross-stitch circumferential suture. A 5–0 coated braided polyester suture and a 5–0 ultra-high molecular weight polyethylene suture were used as the core suture, and a 6–0 polypropylene monofilament was used as the circumferential suture. Tendons repaired with the 5–0 braided polyester suture had gap strengths (2.07 ± 0.46 kgf) and breaking strengths (6.03 ± 0.55 kgf), which were sufficient to withstand an early active mobilization protocol. There were no significant differences regarding mechanical properties between the two suture materials. This combined suture technique has the potential to be utilized in in vivo cases.