Anterior Cruciate Ligament
The rupture of the anterior cruciate ligament is the most common knee injury in medium and large breed dogs.
This injury has two common presentations. One is the young athletic dog playing roughly who acutely ruptures the ligament and is non-weight bearing on the affected hind leg. The second presentation is the older, overweight dog with weakened or partially torn ligaments that rupture with a slight misstep. In this patient the lameness may be acute or there may be more subtle chronic lameness related to prolonged joint instability. In both of these circumstances, you may see the dog have several episodes of lameness that resolves with a few days of rest but then recurs upon other stressful episodes to the leg, as this may start out as a strain or sprain before it finally results in a rupture or tear.
Both of these circumstances are brought about by the lumbar nerves being irritated (like we think of a pinched nerve in our back) which causes the muscles of the leg to be imbalanced. The medial belly of the quadriceps (the large four bellied muscle on the front of the leg from knee to hip) is caused to contract more than the other three bellied and this pulls the knee medially, rotated the femur a few degrees and puts the ACL into a tightened condition that when additional stresses are added, result in damage as strain, sprain, or tear. This tight muscle can always be felt as a tight cord along the front edge of the quadriceps. If rolling your fingers from inside to outside of the thigh areas, it will feel like a very tight cord. Often it can be felt to varying degrees on BOTH legs, as this is a back problem causing the leg problems and the injured one is often just the more severely affected. But this is best palpated by your veterinarian as this is a tight, SORE muscle and must be gently palpated as to not cause pain.
Evaluation by a veterinarian for massage and spinal adjustments can correct the nerves injury in the back, which will result in reducing the contraction of the medial quadriceps and take the stress off of the knee. This can result in your pet healing without further surgical treatment. This will be several months of care and rehabilitation to get to maximum recovery for your pet. Leash walking and no free running will be necessary as well as daily massage by you, as well as the addition of nutritional supplements and herbal supplements to protect the cartilage of the knee and reduce the inflammation and pain. These last steps will happen regardless of whether your pet can recover with or without surgery.
Your surgical veterinarian will perform an orthopedic exam and possibly take radiographs (x-rays) in order to diagnose the severity of this injury. The orthopedic exam involves an analysis of the gait, examination of the joint for swelling and/or pain and the presence of “drawer movement” (the presence of forward instability of the knee joint). Sedation is often required to do an adequate evaluation of the knee, especially in large dogs. Sedation prevents the pet from tensing the muscles and temporarily stabilizing the joint and preventing the demonstration of the drawer sign. Radiographs confirm inflammatory changes in the joint and establish the level of osteoarthritic changes present.
Surgical repair is recommended in many cases by conventional veterinarians to stabilize the joint and prevent further osteoarthritic changes secondary to the joint instability, while natural or holistic veterinarians may discuss spinal adjustments, acupuncture, massage and laser as options prior to or in combination with the surgical treatment.