Patellar Luxation In Dogs
Prevention is better than cure! Find out more about patellar luxation.
What is Patellar Luxation in Dogs
Patella Luxation is basically a dislocation or displacement of the patella (also known as knee cap) from its usual position in the grove at the end of the femur (and trochlea). The patella is at the lower end of the quadriceps group of muscles and is joined to the tibia by methods of the patellar tendon. The patella usually moves up and down in this groove, but should not move out of the groove to either side. When moving out of an opening, it is called luxating patella. The movement from the groove to the inside of the groove is known as is medial luxation and the movement from the groove to the outside is known as lateral luxation. The underside of the patella and the femoral trochlea are each secured with a smooth thin articular ligament which guards the joint.
Patella Luxation can be a result of damage or inherent abnormalities. A congenital malformation where the dog’s legs turn inwards can as well be the causal agent. In the case of the trochlear groove, this is the groove that the patella float in is very shallow or if the distal connection of the patellar ligament is medial instead of central, the kneecap will luxate medially as the knee joint is bent. When this occurs, the dog will have difficulty carrying the weight on the leg until the ligament returns to the right alignment. Sometimes only one knee joint is affected, but the injury can turn two-sided, affecting both of the puppies’ legs in roughly 50% of cases.
A large number of dogs with luxating patella have musculoskeletal abnormalities. These defects include tibia, bowing of femur, inward rotation of the tibia thigh, shallow or absent femoral trochlea and displacement of quadriceps muscle group. Heredity seems to play a role in this problem. Sometimes, the patella luxate due to trauma or injury.
Dogs of any ages can be affected and show signs of either constant lameness or irregular lameness whereby a skipping stride might be seen. Signs might be harder to notice when the issue influences both back legs. A few dogs can deal with luxated patella with little in the way of lameness until secondary arthritis becomes critical. Dogs with irregular lameness may show a perfectly normal leg except for a brief episode of lameness when the patella luxates. A few dogs may stretch their legs allowing the patella to return into tróchlea and continue with no signs of lameness until the patella re-luxates.
It is impossible to prevent instances of patellar luxation that start as a result of abnormal knee development. If you choose a puppy from an at-risk breed, there is no harm asking if any of the puppy’s relatives have symptoms of patella luxation. An ideal approach to prevent patellar luxation is to get rid of the infected animals from the breeding population. Breeders usually do not breed infected dogs or replicate the sire-dam breedings that brought about at least one or more affected offspring. If this is not possible, dogs at risk must be treated carefully in terms of weight and exercise regimens. Dogs may require surgery to return to function normally without pain.
The treatment procedure and long-term diagnosis basically depends on the seriousness of the disorder, which is measured by how regular the patella luxates. It also depends on how well it moves back into the right anatomical position, especially if there are secondary issues such as degenerative joints illness. Most instances of luxating patellas causing lameness require surgery. Every case should be cautiously assessed by the specialist. Techniques usually involve transposition of the tibial tubercle with one or more of the following:
1. Putting a permanent stitch from the patella to the lateral fabella
2. Making the trochlea or groove deeper
3. Discharging the tissue on the internal side of the joint
4. Tightening the tissue on the lateral side of the joint.
Updated: September 21, 2017.