Luxating Patellar surgery has been recommended for your dog as a result of the patella (knee cap) slipping out of the groove that it normally sits in during the flexion and extension of the stifle (knee) joint.
Symptoms of luxating patellar are typically seen in young, small breed dogs which, early on in the disease process exhibit intermittent hopping or skipping on a back leg, with or without pain. As the disease progresses, the movement of the patella in and out of it’s groove (known as the trochlea) causes cartilage erosion, pain and lameness. Patellar luxation, when severe, can be associated with skeletal abnormalities such as bowing of the femur or tibia. Patients with medial patellar luxation are also more prone to developing cranial cruciate ligament disease.
There are a number of contributing reasons for patellar luxation; The most common is that the patella’s attachment to the tibia (shin bone) is too medial (towards the inner side), causing the patella to pull inwards as the quadricep muscle tightens and the stifle extends. Another major contributing factor is the trochlea in affected dogs is not deep enough. As the patella moves from side-to-side, the medial ridge of the trochlea wears down, making it even more difficult for the patella to maintain it’s correct position. There are four grades of patellar luxation:
Grade 1: A knee cap that can be luxated with manual pressure, but otherwise is within the groove.
Grade 2: The knee cap spontaneously luxates, is typically associated with a skipping lameness when the knee cap moves.
Grade 3: The knee cap is permanently luxated but can be manually replaced in the groove.
Grade 4: The knee cap is permanently luxated and cannot be manually replaced in the groove.
Treatment options are dependent on the grade: Surgery is strongly advised for grade 3 and 4 patellar luxation. For grade 2 medial patellar luxation, only dogs exhibiting significant clinical signs, such as lameness, are recommended for surgical management. Surgery is never advised for a grade 1 luxation, for which rehabilitation is strongly recommended.
Tibial tuberosity transposition: The most important component of the repair is to realign the insertion of the tendon spanning between the patella (kneecap) and tibia (shin bone). The bone that this tendon is attached to is cut and moved to a more appropriate position. It is pinned back into place and the bone heals gradually over the following 4-8 weeks.
Resection sulcoplasty: If the groove that the patella normally glides in is very shallow, a surgery is performed to deepen the groove. This involves removal of a wedge or block of cartilage and bone, which is replaced in a recessed position. The goals of treatment are to relieve pain, improve function and reduce the progression of arthritis by re-alignment of the patella mechanism, so that as the quadricep muscle tightens, the patella maintains it’s central position in the trochlea (groove). Surgery, in combination with exceptional postoperative care and rehabilitation can significantly improve the outcome and prognosis for dogs with grades 2, 3 and 4 patellar luxation.
For more information or to discuss this surgery in more detail with one of our veterinary surgeons please contact us on 015394 88555 or visit the referrals section of our website at www.oakhillvetgroup.co.uk