Arthroscopic surgery entails viewing the joint through a quarter inch incision using a miniaturized scope attached to an HD camera. For arthroscopic surgery, three small incisions or portals are made around the joint; one is for the arthroscope tube, one is for fluid egress, and one is for instrument insertion. This approach reduces pain and scaring significantly after surgery compared to opening the joint fully and is used in the stifle for meniscal tears, for shoulder instability and OCD, elbow dysplasia and in hips.
Cranial Cruciate Ligament Repair (CCL)
The most common cause of sudden rear leg lameness in dogs is the rupture of the cranial cruciate ligament (CCL). The problem affects all ages and breeds of dogs, and even cats. The onset of lameness is usually sudden, and the severity of lameness ranges from stiffness or very mild lameness to carrying the leg. The ligament may be partially or completely ruptured. Arthritis develops quickly in dogs because the joint is unstable, making surgical repair necessary.
Around 50% of complete CCL menisci tears in the joint accompany ruptures. The menisci are two cartilaginous pads between the bones. These tears are visualized and removed using arthroscopic examination of the joint during surgery. X-rays are not diagnostic for CCL or menisci injury, so physical exam and history are relied upon for presumptive diagnosis and arthroscopic exam confirms both diagnoses.
Tibial plateau leveling osteotomy (TPLO) is currently the preferred procedure for cranial cruciate rupture or instability in all dogs. TPLO surgery does not repair the ligament, but it changes the biomechanics of the leg so that a CCL is not needed.
Cora CBLO) Based Leveling Osteotomy (CBLO) is a new procedure similar to TPLO, however it offers increased stability due to compression screw, no pivot shift or balcony effect and results in ample bone target. In addition, it can be performed on young dogs and those with an excessive tibia plateau angles, which is found in breeds like bulldogs. Dr. Don A. Hulse, D.V.M. at Texas A&M pioneered this alternate procedure that reduces the tibial plateau angle (TPA) by modifying the proximal tibial procurvatum using center of rotation of angulation.
Each fracture requires evaluation to determine the appropriate steps and fixations to use. Your ACVS surgeon will make his or her recommendation based on the type of fracture. All fractures require patients to have four to eight weeks of kennel rest following surgery to insure bone healing. The length of the recovery time depends on the age and health of your pet as well as the type of fracture. Necessary trips outside must be made on a leash. Patients will also be required to wear an ecollar for two weeks or until sutures have been removed. A follow-up appointment at four to eight weeks confirms healing.
External Fixation involves pins that come through the skin and are supported by a framework of steel pins and threaded rods. This method is initially less costly than other methods, but requires more aftercare diligence on the part of the owner and removal after healing is complete.
Bone plate fixation is the most common method to repair broken bones. A long slender stainless steel plate with holes is applied to the bone using screws to hold the fracture together. There are no external devices and the skin is closed over the plate and soft tissue. Patients are usually able to walk on the leg immediately after surgery.
Interlocking nail fixation is used in complex fractures, those that have large segments of bone missing such as gunshot wounds, and fracture that are close to joints in large breed dogs. A large diameter pin is inserted into the bone cavity and is locked to the bone using screws inserted through the bone and through holes in the pin that are perpendicular to the long axis of the pin. Similar to plate fixation, there are no external devices, and the patient is comfortable immediately after surgery.
Pin and wire fixation is used on spiral type fractures that are long and oblique.
Luxation of the patella or kneecap can occur in any breed of dog. Some are born with the condition while others develop it later on in life. The patella glides in a groove on the front of the knee joint. It slips out to the inside of the groove if the quadriceps, patella and ligament complex are not in alignment. It is easiest to think of the patella and its muscular and ligament attachments as a rope that travels in the groove of a pulley; if the pulley and rope are out of alignment, the rope slips off the pulley.
Repair is usually by alignment of these components, with deepening of the groove. They are aligned by moving the patellar tendon attachment and the bone it attaches to, to the outside of the leg and fixation with a pin.
More complex or difficult cases require realignment of the femur just above the knee joint, and still others that accompany cranial cruciate rupture, require a complicated cut in the bone below the knee to align the bones. Your ACVS surgeon is equipped to make these rather aggressive changes in alignment, which have the value of both pain relief as well functional and cosmetic improvements in gait and conformation.
Tibial Plateau Leveling Osteotomy (TPLO)
Tibial plateau leveling osteotomy (TPLO) is currently the preferred procedure for cranial cruciate rupture or instability in all dogs. TPLO surgery does not repair the ligament, but it changes the biomechanics of the leg so that a CCL is not needed. Although historically TPLO surgery was primarily recommended for larger breeds, the procedure is performed on all sizes and breeds of dogs.
TPLO surgery first involves examining the CCL tear using a small arthroscope to document the type of tear and to remove the torn portion. Then the medial and lateral meniscus cartilages are examined for tearing. If a tear of either meniscus is found, the damaged part of the meniscus is removed using small instrumentation while viewing through the arthroscopy. Next a curved cut in the top of the tibia bone (osteotomy) to include the tibial plateau is made with a saw. The tibial plateau is then rotated along the curved osteotomy in order to change the slope of the top of the tibia according to a predetermined calculation. Next a plate and locking screws are inserted to hold the tibial plateau in place so the bone can heal.
After TPLO surgery, patients are confined to an airline kennel or small room for eight weeks. Short walks are allowed for five minutes or one block. Radiographs are taken at eight weeks postoperatively to confirm bone healing. At this time most dogs have mild or no lameness. Extended leash walks are now added, gradually increasing the distance every ten days. By four months after surgery, most patients have no exercise restrictions. In cases where the surgery is performed within a few weeks of the injury, most dogs return to their previous activities, the most common complication being rupture of the ligament in the opposite leg.
Hip Dysplasia - Total Hip Replacement/FHO/TPO
Arthritis of the hip joints is very common in nearly all breeds of dogs, usually resulting from a growth deformity called hip dysplasia. When diagnosed by 16 weeks old using screening x-rays, hip dysplasia can be prevented using a minor surgical procedure, called symphisiodesis (destruction), of the pelvic growth plate. If dogs are symptomatic meaning they have difficulty getting up are stiff in the morning, and have limited exercise, by 6-14 month old a Triple Pelvic Osteotomy (TPO) is often useful to prevent further damage to the joint. Early x-ray diagnosis is essential to the efficacy of either of these procedures. Small dogs (less than 35 pounds) can usually benefit from Femoral Head and Neck Resection (FHO), which is removal of the ball, or head of the femur, which completely obliterates the joint.
Total hip replacement (THR) has the benefit of restoring the joint to full function, returning the dog’s ability to walk, and eliminating pain. THR is used in young dogs whose hips are out of socket from dysplasia, dogs that have had severe hip trauma, and middle aged and older dogs with chronic dysplasia in which anti-inflammatory drugs do not adequately control pain. Having undergone extensive changes in the last decade, artificial hips were previously cemented in place, and over time the cement predictably loosened, requiring further surgery. Now, as in people, we use press-fit implants that require no bone cement. The implants are precision fit into the bone and stay there at first from bone friction, until the bone grows into the implant for lifetime stability. These rarely, if ever, loosen after bone in-growth approximately three month after surgery.
Currently, Dr. Dean uses the Biomedtrix (Link) biologic fixation implants (BFX) in more than 90% of hips replaced. Some older dogs have weak bone quality such that either the bone is not strong enough to support the implant before the bone in-grows. Also, some dog breeds have bone conformation that will not support the biologic implants. In these cases, which comprise less than 10% of dogs, Dr. Dean will use cement to hold the hip components in place.