Refers to dislocation of patella in dogs, when the patella, small bone located in the front of the knee and that it is necessary to the correct position for the successful operation of the extremity of the animal, is out of place, tróclea, causing pain and functional weakness in the dog.
Within the dislocations, medial dislocation is the most frequent. It comes in 80% of cases while the side only occurs in 20%. Between 30% and 50% of the cases is bilateral, and more frequent in females than in males, above all small breeds and toys.
Lateral dislocations may occur in adult small breeds and puppies of large and giant breeds.
It is a condition that is characterized by a misalignment of the Member, deformations occur during the development of the animal,they do it to patella out of place. It can be due to a congenital disease or, in some cases produced by trauma.
It is advisable that, dogs suffering from this congenital condition, unused in reproduction since it is transmitted across generations.
There are dogs that have dislocation of patella by cause of trauma. In these cases usually the dislocation is associated with a rupture of the anterior cruciate ligament of the knee.
Depending on clinical signs and subsequently of radiological findings, they can be classify dislocations in 4 grades:
Grade I dislocated kneecap intermittent causing limb lameness When is out of place. In the examen dynamic, each three or four steps they lift the leg by flexing the knee or give a small hop.
Grade II -Dislocation that occurs more frequently than in the 1st grade. The patella is luxa easily. There is a slight external rotation of the leg. Many dogs living with this degree for years before progressive arthritis and manifest a limp or more causes serious.
Grade III and IV -The patella is formto permanently dislocated, with noticeable external rotation of the leg. There is moderate lameness. If it is bilateral, dogs walk with their legs bowed, by rotating the foots inwards and loading the weight on the forelimbs. In the most serious cases can be confused with problems in the hips.
In addition, the animal presentspain, crackles and increased sensitivity in the knee, which leads to this decrease its activity, even refuses to go up and down stairs, car or sofa.
Treatment depends on the degree of dislocation and limp, but in the majority of cases required surgical treatment consisting of soft tissue repair, bone reconstruction, or a combination of the two. There are countless techniques and the veterinary orthopedic surgeon choose the or the most suitable in each case.
Among the most commonly used techniques are: superposition of the medial or lateral retinaculum, superimposition of the fascia lata, suture anti-rotation of the patellar ligaments and tibial., desmotomia/capsulectomy,release of the quadriceps, trocleoplastia (condroplastia, trochlear, sulcoplastia, sulcoplastia resection trochlear), transposition of the tibial tuberosity, patellectomy, osteotomy...
As a novelty you are applying orthosis for dislocation of the knee as a means of orthopaedic conservative treatment that allows to keep the ball inside condi them the femoral and avoid pain and instability. These orthosis are made to measure and are very useful in cases where surgery has failed, can not or do not want to operate for various reasons.
Marta Subirats & Toni Ramon
Physiotherapists of animals
Technical team of canine orthopedics