Resumen de Análisis comparativo de la rigidez al desplazamiento antero-posterior de la rodilla canina completa, rodilla con rotura del ligamento cruzado anterior y rodilla reparada con la técnica de avance de la tuberosidad tibial
Marta Musté Rodríguez
In canine traumatology, one of the most common knee pathologies is torn cruciate ligament (ACL), the diagnosis and treatment costs were 1.32 billion dollars in the U.S. during 2003. The short-term effects are instability of the knee, osteoarthritis, meniscal injuries, pain and loss of function of the joint. The ACL acts as a joint stabilizer. Its function is to limit anterior displacement of the tibia relative to the femur, internal tibia rotation and hyperextension of the knee. Treating ACL rupture has caused much controversy and difficulty for the veterinary surgeon because of the large number of techniques that exist, both intracapsular and extracapsular, as none of these surgical techniques definitively detains the progression of degenerative joint disease. Besides the classic techniques listed above, in recent years techniques to amend the biomechanics of the knee have been applied to repair ACL tear. There are studies that suggest better functionality in animals that have undergone these techniques, compared to conventional techniques, especially in the case of heavy animals. The technique of tibial tuberosity advancement (TTA), is aimed at amending the biomechanics of the knee to remove the anterior-posterior displacement of the tibia relative to the femur (drawer effect) in the knee after ACL rupture. In this thesis we work with the TTA device patented by Drs. Durall and Diaz-Bertrana. The drawer effect is simulated in the canine knee by experimental tests on 5 femoro-tibial joints in dog cadavers, applying tangential forces in anterior-posterior direction. The data required to compare the rigidity presented in an anatomically complete knee, one without ACL and one repaired applying Tibial Tuberosity Advancement Technique (TTA) is obtained. In all specimens that we tested, there was a significant loss of rigidity in the knee, the anterior displacement of the tibia, after removing the ACL. This loss of rigidity is around 78% of that of the complete anatomic knee. By applying this technique to repair the knee, TTA studied in this thesis, the rigidity is increased, doubling in value against the knee without ACL. If, with the TTA system the rigidity value of the healthy knee is not reached, this is offset by the modification of the anatomy of the joint. By changing the biomechanical behavior, the tangential component of cranial force in the joint declines or stops which produces the anterior drawer effect. From February 2011 to July 2013 at the veterinary clinic at UAB, 60 dogs with ACL tear underwent surgery using the TTA technique with this device. In 100% of cases animal lameness had disappeared and knee functionality had been recovered.
