The effect of Tibial Tuberosity Advancement on Patellar tendon force in Canine Stifle Joint under Caudal Femoral Drawer

The Tibial Tuberosity Advancement (TTA) surgical technique is used in veterinary surgery to limit cranial tibial translation during canine gait, lengthening the lever arm of the quadriceps in Anterior Cruciate Ligament-deficient (ACL-deficient) stifle joints. It is know that after TTA, the patellofemoral pressure decreases, but the Patellar Tendon (PT) behavior has not been observed experimentally yet. This study measures the PT force under caudal femoral drawer at knee flexion angles from 135° to 90° in intact and pathological knee to asses the effect of TTA on the tendon. Five fresh cadaveric adult canine stifle joint were tested in an apparatus in which muscle forces of the canine hind limb were simulated. Each knee was tested in three different conditions: intact, ACL-deficient and with TTA. PT force was measured using a electrical transducer. The greater the joint flexion angles, the greater the PT force. The knee average force of the five specimens in 90º flexion were 28.4 ± 3.2 Newtons (N) for the intact, 28.2 ± 3.4 N for the ACL-deficient and 24.9 ± 2 N for the TTA knee, which decreased compared to the healthy knee, so TTA generates a loosening of the PT force. The PT force showed a fast rate of change in the operated knee because of a shift in the pattern of knee flexion, so the biomechanics of the entire joint could be influenced by the TTA technique.

Rehabilitation of the canine stifle – a practical guide

This article is the last in a series of practical guides to rehabilitating the canine shoulder, elbow, hip, stifle and spine. This article looks at the stifle, including a brief description of the common conditions affecting this joint, followed by a practical guide on the various techniques used for rehabilitation following injury or surgery, or for management of long-term conditions affecting the stifle.

Acoustic radiation force impulse (ARFI) elastography of the stifle joint of healthy beagles

ABSTRACT The objective was to establish the reference standards for elastography of the main structures of the canine stifle joint. The medial meniscus, patellar and cruciate ligaments of thirty healthy beagles was evaluated by B-mode and ARFI elastography (n=60 joints). Analysis detected a positive correlation of the shear wave velocity (SWV) of structures according to age. Patellar ligament presented a gradual stiffness increase in relation to age, while medial meniscus and cruciate ligament were more rigid in puppies than in adults. However, greater stiffness of these structures was observed in elderly animals. Elasticity of each structure was evaluated according to gender and reproductive status. Females presented greater stiffness of all structures, with SWV differing 0.3 and 0.36m/s between genders. Only the medial meniscus was not stiffer in neutered animals when compared to intact animals, differing only 0.02m/s in menisci and 0.4 to 0.47m/s in ligaments between groups. These findings corroborate with literature data that states a higher prevalence of ligament insufficiency in elderly dogs, females and neutered animals. It was concluded that ARFI elastography of the canine stifle joint is feasible and its application can be potentially effective in early diagnosis of ligament and meniscal changes.

Modelling the Effects of Cranial Cruciate Ligament Transection, Medial Meniscal Release and Triple Tibial Osteotomy on Stability of the Canine Stifle Joint

Objective The aim of this study was to evaluate the ex vivo effects of sequential cranial cruciate ligament transection (CCLx), medial meniscal release (MMR) and triple tibial osteotomy (TTO) on canine stifle stability compared with the intact state, across a wide range of joint angles. Study Design Nine right hind limb preparations were instrumented to provide constant quadriceps and gastrocnemius loads in a 3:1 ratio, and extended from full flexion during fluoroscopic recording. Recordings were repeated after each of CCLx, MMR and TTO. Fluoroscopic landmarks were used to calculate tibial subluxation and patellar ligament angle. Results Medial meniscal release resulted in additional cranial tibial subluxation compared with CCLx. Triple tibial osteotomy restored stifle stability up to a joint angle of 125 degrees. The presence of the crossover angle could be inferred from the patellar ligament angle and subluxation curves. Conclusion Our results suggest that in the cranial cruciate ligament-deficient stifle, the crossover angle at which loading shifts between the caudal and cranial cruciate ligaments is dependent on both loading and integrity of the medial meniscus. Triple tibial osteotomy improves stifle stability over a wide range of joint angles under a quadricep to gastrocnemius loading ratio of 3:1 by converting cranial tibial thrust to caudal tibial thrust, due to TTO increasing the amount of joint extension required to reach the crossover angle.