Management

	The owner has the option of conservative or surgical therapy.  Conservative 
therapy is best for small dogs in that they will reach satisfactory recovery after 2 months 
of enforced rest.  However, since Bonnie is a large labrador retriever, conservative 
therapy might not be as successful.  The owner may try to confine Bonnie for 4-8 weeks 
and provide analgesic support but if lameness persists even after 8 weeks of strict rest, 
surgery should be considered.

	There are many surgical options available for Bonnie.  Many orthopedic 
specialists recommend immediate surgical repair for large breed dogs.  The choices of 
surgery include: intracapsular reconstruction, extracapsular reconstruction, modified 
extracapsular reconstruction, tibial plateau leveling osteotomy, and fibula head 
transposition. There is no one surgical approach proven superior to others.  In our 
opinion, the intracapsular repair is best for large breed dogs.  There are two types of 
intracapsular repair, Under and Over and Over the Top. Intracapsular repair is a 
popular approach because of it mimics the course of the CrCL by placing an autogenous 
tissue graft through the joint.  This prevents cranial displacement of the tibia during 
weight bearing.  

Under and Over surgery is begun with a lateral parapatellar approach.  The lateral 
one third of the patellar tendon is dissected from the patella.  The landmark for the distal 
extent of the incision is the palpable tuberosity cranial to the groove of the long digital 
extensor muscle.  A periosteal elevator is used to separate the patellar tendon in the fascia 
lata from the joint capsule.  The fascia lata is included in the graft.  The graft is freed 
from the joint capsule and reflected from the lateral patellar surface.  Lateral arthrotomy 
is the next step.  Right angled forceps are passed from the joint to under the intermeniscal 
ligament.  The graft is then pulled through the fat pad and under the intermeniscal 
ligament into the joint.  Forceps are passed between the femoral condyles into the joint to 
grasp the graft and pull it through the joint.  The graft is then pulled through a small 
incision made between the fabella and the femur.  The graft will be looped around a 
screw, placed in the femur under a spiked washer, and pulled tight as the screw is 
tightened.  The end of the graft is sutured to itself.

Over the Top surgery is very similar to Under and Over.  A lateral approach to the 
stifle joint is performed.  The graft is isolated from the lateral patellar tendon and 
retinaculum.  A tunnel is drilled from the cranial surface of the tibia to the insertion of the 
CrCL inside the joint.  The graft is pulled through the tibial tunnel and over the top of he 
lateral condyle.  

Both techniques initially rely on the graft for support of the joint and eventually 
will rely on the scar tissue.  The results of intracapsular techniques have been very 
consistent and show a high success rate. The only disadvantage is that this technique does 
take more surgical effort and equipment.  

During surgery, meniscal and cartilage damage was evaluated.  If significant 
meniscal damage was noted, it will be removed.

A bandage will be placed on the left rear limb for 2 weeks post surgery with 
occasional changes as needed.

Bonnie will be confined to a cage/crate for 10 days.  A controlled exercise 
program will be initiated 2 weeks after surgery.  This may include leash walking and if 
possible controlled swimming.  Post surgical physical therapy is important for improving 
mobility and strength. This may include ice packing and range of motion exercises,
 massages, and muscle electrical stimulation. The joint has minimal inherent strength 
until 6 weeks after the repair.  12 weeks after surgery, Bonnie should return to normal 
function.  Weight loss will be extremely beneficial for Bonnie to decrease the load and 
stress on the stifle joint.  

Bonnie should be placed on NSAIDs and analgesics.  These will be 
symptomatically given for synovitis and possible degenerative joint disease.  We 
recommend carprofen or for minor pain a buffered or enteric coated aspirin.  
Corticosteroids should be avoided due to possible articular cartilage damage associated 
with long term use.  

Prognosis

Regardless of the surgical technique chosen, the success rate will be about 85%.  
However, DJD is often a common sequela and Bonnie is not likely to return to complete 
athletic function.  Up to 40% of dogs that experienced a unilateral CrCL rupture will, 
within 17 months, rupture the contralateral ligament.  Up to 15% of dogs will need a 
second surgery on the same limb due to subsequent meniscal damage.  Within a few 
months, Bonnie will be able to return to her daily walks with her owner.