Three-dimensional kinematic evaluation of lateral suture stabilization in an in vitro canine cranial cruciate deficient stifle model

The impact of surgical correction of cranial cruciate ligament rupture (CCLR) on 3D kinematics has not been thoroughly evaluated in dogs. The success of current techniques remains limited, as illustrated by suboptimal weightbearing and progression of osteoarthritis. The inability to restore the stifle’s 3D kinematics might be a key element in understanding these suboptimal outcomes. The objective of this study was to evaluate the impact of lateral suture stabilization (LSS) on the 3D kinematics of the canine stifle joint. We hypothesized that LSS would not restore 3D kinematics in our model. Ten cadaveric pelvic limbs collected from large dogs (25–40 kg) were tested using a previously validated apparatus that simulates gait. Three experimental conditions were compared: (a) intact stifle; (b) unstable stifle following cranial cruciate ligament transection (CCLt) and (c) CCLt stabilized by LSS. Three-dimensional kinematics were collected through 5 loading cycles simulating the stance phase of gait and curves were analyzed using a Wilcoxon signed-rank test. LSS restored baseline kinematics for the entire stance phase for cranial and lateromedial translation, flexion, and abduction. It restored distraction over 90% of the stance phase. Internal rotation was limited, but not restored. This in vitro study had limitations, as it used a simplified model of stifle motion and weight-bearing. The results of this study report that LSS can restore physiologic 3D kinematics largely comparable to those of healthy stifles. Suboptimal outcome in patients following CCLR stabilization by LSS may therefore result from causes other than immediate postoperative abnormal 3D kinematics.

Treatment of cranial cruciate ligament rupture in the feline stifle

SummaryObjective: To determine whether a lateral suture placed with bone anchors between quasi-isometric points in a cat is superior to a standard fabella-tibial suture for the stabilization of cranial cruciate ligament (CrCL) rupture compared to an intact stifle joint.Study design: Biomechanical cadaveric study.Methods: Six stifle joints with intact cruciate ligaments from three skeletally mature cats were placed in a loading mounting set and tested with axial loads of 20N and 60N at three different joint angles (75°,130° and 160°). The procedure was repeated with a transected CrCL; a stabilized stifle joint after a combination of three lateral suture techniques (fabella-tibial suture technique [SFT]; femoro-tibial suture technique 1 [FTS-1] and femoro-tibial suture technique 2 [FTS-2]). Radiographic examination of the relative position of the tibia to the fixed femur was compared.Results: Stabilization of the stifle joint with lateral sutures had comparable stability to the intact specimens in the cranio-caudal direction (p = 0.2) but not in the proximo- distal direction for the SFT (p = 0.04) and FTS-2 technique (p = 0.03). There was no significant difference between the three stabilization techniques (p >0.05).Clinical significance: Lateral sutures placed with bone anchors at quasi-isometric points performed better than SFT and FTS-2 in stabilizing the feline stifle after CrCL rupture in the proximo-distal plane. Biomechanical stability in the cranio-caudal plane after placement of a lateral suture across the feline stifle was similar to the intact CrCL.

Tensions generated in a lateral fabellotibial suture model

SummaryObjectives: To compare suture tension on a simulated lateral fabellotibial suture model using various methods of application of tension, fixation, and suture materials.Methods: Veterinarians constructed simulated lateral fabellotibial suture constructs on a tying stand with a force sensor. Participants used combinations of 45 kg test mono-filament nylon, metric 7 braided polyethylene, crimps, crimper, or knots, with their choice of instruments to secure the constructs. The tension in completed constructs was measured and comparisons were made between nylon and polyethylene, the use of crimps compared to knots, and the use of a mechanical distractor compared to hand tightening techniques. A value of p <0.05 was considered significant.Results: Fifty-eight veterinarians created 72 lateral suture constructs. Final tensions generated ranged from 1.4–171.0N. The median tension of nylon sutures (43.9N ± 44.7N) was significantly greater than polyethylene sutures (9.5 N ± 19.6N). The median tension of constructs secured with crimps (62.8N ± 42.4N) was significantly greater than constructs secured with knots (11.8 N ± 14.8N). The mechanical distractor generated significantly higher median tension (78N ± 50.4N), compared to methods without the device (18.6 N ± 25.1N).Clinical significance: There was a large variability in the tension generated in simulated lateral fabellotibial constructs. Veterinarians who used nylon, crimps, and the mechanical tensioner generated constructs with greater tensions.

Clinical comparison and short-term radiographic evaluation of Tight Rope and Lateral Suture procedures for dogs after cranial cruciate ligament rupture

The aim of this study was to monitor short-term osteoarthrosis progress in relation to a recently introduced novel extracapsular method called the Tight Rope procedure and after Lateral Suture with nylon in cruciate-deficient dog stifle joints. Twelve dogs were included in the study. Treatment type was not randomised. Mediolateral radiographs from 12 stifle joint were evaluated preoperatively and six months after surgery. A modified scoring system for evaluation of osteoarthrotic changes was used. The initial osteoarthrotic score in the TightRope group ranged from three to six and in the Lateral Suture group from 0 to 11. In the TightRope group 66.6% of dogs had an osteoathrotic score difference of &le; 5 and 33.3% dogs had an osteoarthrotic score difference of &gt; 5. For the Lateral Suture group 50% of dogs had an osteoarthrotic score difference of &le; 5 and 50% dogs had an osteoarthrotic score difference of &gt; 5. The Wilcoxon signed rank test revealed a significant difference between preoperative and postoperative osteoarthrotic scores (P = 0.0038). No significant differences were noted between TightRope and Lateral Suture groups in terms of changes in mean radiographic osteoarthrotic score preoperatively and at the six-month postoperative end point. Both groups had numerically higher radiographic scores six months after surgery. &nbsp;

Effect of tibial insertion site for lateral suture stabilization on the kinematics of the cranial cruciate ligament deficient-stifle during early, middle and late stance

SummaryObjective: To evaluate the effect of two tibial attachment sites for lateral suture stabilization (LSS) on the three-dimensional femorotibial translational and rotational movements of the cranial cruciate ligament-deficient canine stifle during the early, middle and late stance phases.Study design: In vitro biomechanical study: 32 hindlimbs from 16 canine cadavers.Methods: Limbs were mounted in a testing jig and an electromagnetic tracking system was used to determine the three-dimensional femorotibial translational and rotational movements under 33% of body weight load during early, middle and late stance in the following sequence: cranial cruciate ligament-intact, cranial cruciate ligament-deficient and LSS with the distal anchor through the tibial tuberosity (LSSTT) or through the cranial eminence of the extensor groove (LSSEG). The proximal anchor point was the lateral femorofabellar ligament.Results: Post-LSS stifle three-dimensional femorotibial translational and rotational movements were more comparable to normal than post-transection movements for both techniques. Both LSS techniques restored femorotibial movements in cranial cruciate ligament-deficient stifles to varying amounts but neither technique successfully restored normal three-dimensional femorotibial movements. The LSSEG improved femorotibial movements of the cranial cruciate ligament-deficient stifle in the medial-lateral direction and axial rotation but performed poorly in restoring femorotibial movements in the cranial-caudal direction as compared to the LSSTT.Clinical significance: Both the LSSTT and LSSEG techniques failed to completely restore normal three-dimensional femorotibial translational and rotational movements in cranial cruciate ligament-deficient stifles in vitro.