In Vitro Evaluation of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair Systemtm

Long-term clinical and goniometric follow-up of lateral suture surgery in dogs with cranial cruciate ligament rupture

The aim of this study was to evaluate the complications and the short-, medium-, and long-term outcomes following treatment of cranial cruciate ligament (CCL) rupture in dogs using the lateral fabello-tibial suture technique. The patients were ten dogs of various breeds, 62.5 ± 18.8 months of age, weighing 30.2 ± 3.3 kg, with unilateral CCL rupture. At 2, 6, 12, 24, and 52 weeks after surgery, the dogs were re-evaluated with clinical examination, gait and pain analysis, and radiography. A major complication was identified in one dog (10%), requiring second surgery due to implant failure and destabilisation of stifle joint. Minor complications occurred in two dogs postoperatively (one late meniscal injury and one case of seroma formation). The short-term outcome at two and six weeks postoperatively was considered good in six dogs and satisfactory in four dogs, while the mid-term outcome (between 12 and 24 weeks) was good to excellent in eight dogs and satisfactory in two dogs. All ten dogs had a good to excellent outcome 52 weeks after surgery. The lateral suture technique is generally safe and given the major benefits, such as lower costs, lower technical difficulty, and minimal requirement for specialised equipment, will probably remain a popular and alternative method for treatment of CCL insufficiency in dogs with good degree of owner satisfaction.

Use of a custom-made limb-press model to assess intra- and extracapsular techniques for treating cranial cruciate ligament rupture in cats

Objectives This study aimed to compare the under-and-over technique, a type of intracapsular treatment, and the standard fabella-tibial suture, a method for extracapsular treatment, in achieving immediate, postoperative stifle stability after cranial cruciate ligament (CrCL) rupture by using a feline, custom-made limb-press model. Methods Cadaveric feline hindlimb specimens (n = 14) were positioned in the limb press at predefined joint angles (stifle joint: 120°; hock joint: 120°), and vertical loads of 5%, 10%, 20% and 30% body weight were applied statically. Mediolateral radiographic views were obtained of the stifles under each load before and after CrCL transection, as well as after treatment with either of the two surgical techniques, and differences in distance between two predefined radiographic points for each radiograph were analysed. Results The general linear model showed a significant effect of load ( P <0.01) and technique ( P = 0.004) and a significant interaction between load and technique ( P = 0.006) regarding craniocaudal stifle stability. Distances between predefined tibial and femoral reference points were consistently higher in transected CrCLs than in intact stifles. All standard fabella-tibial suture-treated stifles (n = 7) were stable at all loads tested. Of the seven under-and-over technique-treated stifles, one was unstable at 20% body weight load and three at 30% body weight load. Conclusions and relevance Our model, which appropriately reproduced certain aspects of domestic shorthair cat stifle mechanics, indicated that a 40 lb monofilament nylon prosthesis, tightened at 20 N, produces more favourable biomechanical stabilisation of craniocaudal cruciate-related stifle instability than a 0.5 cm wide strip of fascia lata applied intracapsularly.

In vitro mechanical evaluation and comparison of two crimping devices for securing monofilament nylon and multifilament polyethylene for use in extracapsular stabilization of the canine stifle

OBJECTIVE

To compare the tensile strength and stiffness of non-absorbable suture loops created with two types of crimping devices.

METHODS

Loops of monofilament nylon leader line (MN) of 18 kg, 36 kg, and 45 kg multifilament polyethylene (MP) with a crimp and MP with a crimp and knot were mechanically tested to failure in quasistatic tensile loading after being created with either a wave pattern crimp device or three applications of a single crimp device. Each testing group consisted of five samples. Tensile loading to failure at a rate of 9.5 mm/s was used. Failure was defined as a sudden drop in the recorded force.

RESULTS

All suture materials failed by breaking near the crimp tube with both crimp devices, with exception of the MP without knot, which slipped through the crimp tube using both devices. Sutures secured with the wave pattern crimping device were significantly stronger with a higher load yield, maximum load, displacement yield, failure displacement, and maximum displacement than the single crimp device. Loops of MP suture crimped by either device plus the addition of a surgeon's knot resulted in a significantly stronger construct than unknotted crimped MP constructs. Crimped MP combined with knot were significantly stiffer, but not stronger, than crimped 45 kg MN.

CLINICAL SIGNIFICANCE

Performing extra- capsular repair for ruptured cranial cruciate ligaments with the wave pattern crimp system may result in lower failure rates due to the construct being significantly stronger than the single crimp system.

Mechanical evaluation of hydrogen peroxide gas plasma sterilization of nylon lines used for extra-articular stabilization of the canine stifle joint

OBJECTIVE

To compare the effects of hydrogen peroxide gas plasma (HPGP) and ethylene oxide (EO) sterilizations on the mechanical properties of nylon lines used for stabilization of the canine stifle. Secondarily, to compare the performance of crimped and knotted lines.

STUDY DESIGN

In vitro mechanical evaluation.

SAMPLE POPULATION

Nonsterilized, EO- and HPGP-sterilized specimens of 36.3 kg test nylon leader line (NLL) and 57.8 kg test nylon fishing line (NFL).

METHODS

Single strands and looped specimens of NLL or NFL were positioned on a material testing machine. To create looped specimens, NLL were crimped using the Securos system, and NFL were knotted, as used clinically. Elongation (%) and ultimate load (N) variables were studied.

RESULTS

Elongation and ultimate load of NLL groups were not significantly different between EO and HPGP. For NFL, HPGP sterilization led to slightly greater elongation than EO in loops only. Ultimate load of NFL single strands was not significantly different between EO and HPGP, but was higher after HPGP compared with EO in NFL loops. All NLL groups had less elongation and ultimate load than NFL.

CONCLUSION

The effects of HPGP on NLL compared positively to EO, making HPGP an attractive alternative. As HPGP led to a slightly greater elongation of NFL than EO, the latter could be favored to sterilize NFL. Crimped NLL minimized elongation better than knotted NFL.

CLINICAL RELEVANCE

Sterilization with HPGP seems a good alternative to EO for NLL. EO may be a better choice for NFL; however, it is difficult to judge the clinical relevance of this result. Crimped NLL minimizes elongation and may help reducing the recurrence of stifle instability postoperatively.

Mechanical Comparison of Two Knots and Two Crimp Systems for Securing Nylon Line Used for Extra-Articular Stabilization of the Canine Stifle

OBJECTIVE

To compare mechanical properties of knotted and crimped nylon loops.

STUDY DESIGN

In vitro mechanical evaluation.

SAMPLE POPULATION

Loops of 27 kg-test nylon leader. Single strand-clamped square knot compared with 2 crimp systems. Two strand--self-locking knot compared with 2 crimped loops.

METHODS

(a) Single pull to failure (n = 10) at 500 mm/min. Initial loop tension (N), peak load (N), peak elongation (mm), stiffness of the linear portion of the curve (N/mm), and failure mode were recorded. (b) Incremental cyclic loading to failure (n = 5)--each loop was cycled 5 times to 100 N at a loading rate of 200 mm/min. Cycling was repeated, with the load increased by 50 N after each set. Elongation (mm), tension remaining (N), and after permanent deformation was present, elongation at 10 N (mm) were measured.

RESULTS

Initial tension and stiffness were greater for crimped loops when compared with knotted loops. There were no differences between crimped loops. The self-locking knot elongated more, and was less stiff, when compared with 2 crimped loops. With incremental loading, knotted loops elongated more than crimped loops. The tension remaining in the loop fell below 10 N more quickly for knotted loops compared with crimped loops.

CONCLUSION

Crimped loops are stiffer, and resist both static and cyclic load more effectively before becoming permanently elongated, when compared with knotted loops.

CLINICAL RELEVANCE

Stifle stability will be maintained more effectively by crimped nylon loops when compared with knotted loops.

Mechanical Evaluation of Two Loop Tensioning Methods for Crimp Clamp Extracapsular Stabilization of the Cranial Cruciate Ligament-Deficient Canine Stifle

OBJECTIVES

To describe a method of tightening nylon loops secured with a crimping system for extracapsular fabello-tibial stabilization of the cranial cruciate ligament-deficient stifle and to compare this with a method using a commercially available tensioning device.

STUDY DESIGN

In vitro mechanical testing.

METHODS

Fourteen standardized nylon loops were tensioned using a tensioning device and secured with crimp clamps. Another 14 loops were tightened by partially securing the crimp clamp, followed by tightening of the loop by hand, before definitively securing the crimp clamp. Loops were loaded to failure in a materials testing machine.

RESULTS

Mean ultimate loads for instrument-tightened and hand-tightened loops were 383.7 and 371.4 N, respectively. Mean stiffness values for instrument-tightened and hand-tightened loops were 59.7 and 59.3 N/mm, respectively. These differences were not significant.

CONCLUSIONS

The hand tightening method does not affect the mechanical properties of the loop.

CLINICAL RELEVANCE

The hand tightening method described is a valuable technique for unassisted surgeons without access to tensioning devices.

Mechanical Evaluation of Two Crimp Clamp Systems for Extracapsular Stabilization of the Cranial Cruciate Ligament-Deficient Canine Stifle

OBJECTIVE

To compare the mechanical properties and interoperator variabilities of 2 crimp clamp systems for extracapsular, fabello-tibial, nylon loop stabilization of the cranial cruciate ligament-deficient stifle in dogs.

STUDY DESIGN

In vitro mechanical testing.

METHODS

Three operators with different grip strengths each secured 20 standardized nylon loops using stainless-steel crimp clamps: 10 using a Veterinary Instrumentation system (45 kg [100 lb] test nylon leader line, 12 mm crimp clamps) and 10 using a Securos system (36 kg [80 lb] test nylon leader line, 36 kg [80 lb] crimp clamps). Loops were tensile loaded to failure in a materials testing machine.

RESULTS

Mean ultimate load and mean stiffness were significantly higher for the Securos (336.9 N, 60.6 N/mm) than for the Veterinary Instrumentation system (113.8 N, 37.0 N/mm). For both systems, ultimate load was subject to interoperator variability.

CONCLUSIONS

The Securos loops were significantly stronger and stiffer than the Veterinary Instrumentation loops for all operators, but significant differences between operators for ultimate load existed for both systems.

CLINICAL RELEVANCE

Securos fabello-tibial sutures will withstand greater loads than Veterinary Instrumentation sutures and this is particularly true for sutures created by surgeons with reduced grip strength. It may be necessary to use more than 1 Veterinary Instrumentation suture to match the ultimate load and stiffness of a Securos suture.