Surgery for pets – BluePearl Pet Hospital in Raleigh, NC.

Knee (stifle joint) problems.

A pet’s stifle is the joint that connects the upper and lower leg bones—the femur and the tibia. In people, it is considered the knee. While there are numerous conditions that can affect the knee joint, the most common are:

Cranial cruciate ligament rupture: The cranial cruciate ligament is an extremely important stabilizer inside your pet’s knee. The ligament can be damaged as a result of injury or degeneration. Rupture of this ligament either partial or complete and results in joint instability, cartilage damage, inflammation and arthritis. The menisci are the cartilage-like disc that sits between the femur (thigh) and the tibia (shin) bones. They serve as a shock absorber, position sensor and load bearer within the joint and can be damaged when the cranial cruciate ligament is ruptured.

Patellar luxation: The patella (or kneecap) is a small bone that is situated in a groove within the femur (thigh bone) in the kneecap. This bone helps the knee function, allowing it to flex and extend normally. Patellar luxation is a condition where the kneecap is dislocated either towards the inside of the limb (medial) or the outside (lateral). Patellar luxation typically occurs because of malalignment of the muscles and bones of the hind limb. While this occurs most often in dogs, cats can experience patellar luxation as well.

Osteochondritis dissecans: Osteochondrosis is the abnormal development of cartilage at the end of the bone. This condition is most often seen in young medium to large-breed dogs. With normal activity, cracks may occur in the diseased cartilage resulting in the formation of a flap and exposure of the underlying bone to the joint environment.

Signs and symptoms.

Cranial cruciate ligament: Some of the common signs and symptoms associated with a rupture of the cranial cruciate ligament include any combination of:

  • Trouble rising from a sitting position
  • Pain and stiffness
  • Difficulty jumping on furniture or into a car
  • Unwillingness to play/decreased activity level
  • Limping
  • Decreased range of motion
  • Popping sound when joint is being used
  • Swelling or thickening of the joint, especially on the inside of the shin bone

Patellar luxation: Symptoms and their severity can vary. Most pets will suddenly carry the affected limb up for a few steps which may look like they are skipping but then shake or stretch their leg before they regain full use. As the condition progresses, the lameness becomes more frequent and may become continuous.

Osteochondritis dissecans: Pets with this condition usually begin limping on the affected leg(s). In many cases, the limping is gradual and improves after rest but becomes more pronounced after exercise. Although your pet may be limping on one leg, the condition may be present in the other leg as well. In some pets, the affected joint may be swollen and warm to the touch.


Cranial cruciate ligament: Our specialists typically diagnose complete ruptures of the cranial cruciate ligament with a comprehensive physical examination including palpation, gait observation and x-rays. Partial ruptures may not result in gross instability of the joint and may have more subtle physical exam and imaging findings.

Patellar luxation: An orthopedic examination and palpation of an unstable knee is the best way to diagnose this condition. Additional tests may be needed such as:

  • Palpation under sedation to assess damage to ligaments
  • X-rays
  • CT scans, which can help our surgeons plan for surgery if needed

If undiagnosed, this condition can potentially lead to the rupture of the cranial cruciate ligament.

Osteochondritis dissecans: Diagnosis of OCD requires radiographs or a CT scan to look at the stifle joint. In some cases, arthroscopic examination may be needed to confirm a diagnosis.


Cranial cruciate ligament: There are surgical and non-surgical treatments for this condition, but they depend on your pet’s activity level, size, age, skeletal conformation and degree of knee instability. In general, surgery is the most predictable way to improve the stability of the joint. Typically, there are two types of surgeries that can address knee instability:

  • Osteotomy-based techniques require a bone cut to change the biomechanics of the knee. These techniques are most commonly recommended for medium to large breed dogs but can be performed in smaller dogs as well. These techniques predictably result in a rapid return to function and an excellent long-term outcome. A number of similar techniques exist and may be discussed during your visit.
  • Suture-based techniques are divided into two categories. These procedures aim to replace the function of the torn ligament using a prosthetic suture material placed outside the joint, between the femur and tibia. Our surgeons perform standard lateral suture repairs, Tightrope® and bone-anchor stabilization procedures. These procedures are most often recommended for small to medium dogs though may be performed in larger dogs depending on their specific anatomy. Non-surgical treatment involves pain medication, joint supplements, exercise modification, rehab and in some cases braces or orthotics.

Patellar luxation: For pets with patellar luxations that aren’t experiencing symptoms, they may not require surgery. For those cases that do require surgery, a number of techniques may be required to keep the kneecap in place:

  • Surgery to reconstruct the soft tissue surrounding the kneecap to loosen the side that it has moved towards and tighten the opposite side, placement of sutures to hold the knee and kneecap in place
  • Surgery to deepen the femoral groove which is where the kneecap sits so that it doesn’t slip to either side
  • Surgery to realign the muscles/bones of the hind limb

Osteochondritis dissecans: Treatment depends on the severity of the damaged cartilage. Surgical treatment typically involves removing the cartilage flap from the joint and treatment of the resulting defect to encourage healing. Alternatively, the defect may be filled with a cartilage transplant or synthetic plug to reconstruct the joint surface.

Orthopedic trauma.

Dogs and cats have skeletons that are similar to ours. The bones of their skeleton can break (fracture) for many of the same reasons that our bones break. These can include sporting injuries, fights, falls, motor vehicle trauma, underlying bone diseases (pathologic fractures) and other unwitnessed trauma. Also similar to people, dogs can experience strains, sprains and tears of ligaments, tendons and muscles. These can be related to chronic overuse or sudden trauma and the initial signs of these injuries are often indistinguishable from the signs seen when a bone is broken.

Signs of broken bones or injured tendons/ligaments can vary depending on the location of the injury, but may include:

  • Severe lameness
  • Holding up a leg
  • Swelling
  • Pain or abnormal movement or angle of a limb

However, some animals will bear weight on a broken bone or damaged joint depending on the location or type of injury.

At the opposite extreme, major trauma (such as motor vehicle trauma) may lead to multiple orthopedic and soft tissue injuries, and these pets may be unwilling (or unable) to get up or move around at all. Major trauma that causes broken bones or torn ligaments/tendons may also damage internal organs (lung bruising/puncture, internal bleeding, bladder rupture) that may be more critical and require treatment or evaluation prior to treatment of the fracture.

Some diagnostic tests are needed prior to the repair of a fracture or joint injury. These can vary depending on the injuries of the individual pet, but generally include radiographs (x-rays) of the injured body part and blood work to evaluate organ function prior to sedation or anesthesia. In pets with major trauma, additional diagnostics may be needed to more thoroughly evaluate for internal injury. These tests may include chest radiographs, abdominal radiographs or abdominal ultrasound. In cases of spinal injuries or when more complex fractures are present, a CT scan or MRI is typically recommended.

Treatment of broken bones or joint injuries can be divided into four steps:

  1. Initial at-home treatment
  2. Temporary stabilization
  3. Definitive stabilization
  4. Post-operative care

1. At-home treatment.

Dogs and cats with orthopedic trauma should be seen as soon as possible by your veterinarian or an emergency veterinarian in your area to evaluate the injuries and treat pain. While you are preparing to transport your pet, they should be confined to a small area (crate or very small room) to limit motion. Care should be taken during any movement of your pet, because they may bite or injure a family member due to being in significant pain.

You should not give any medications or apply anything to the injury site without consulting your veterinarian because in some cases this can cause further injury. It is important to remember that many over-the-counter human medications can be harmful or toxic to your pet. If you are not able to bring your pet to a veterinarian immediately, please call for instruction.

Closed fractures (no skin wounds at the location of the broken bone) should ideally be treated within 2-4 days of the injury. Open fractures (skin wound over the location of the broken bone with or without exposure of bone) ideally need initial cleaning within 8 hours of the injury to prevent deep bone infections, but final treatment is often delayed for 1-2 days to allow wound management to start. Tendon or ligament injuries may be stabilized externally for a period of time prior to definitive treatment.

2. Temporary treatment.

Temporary treatment usually involves immobilizing the injury site until definitive stabilization can be applied. Injuries below the knee and elbow are often immobilized using a bandage with a splint inside it. Injuries above the elbow and knee are best immobilized with slings to prevent weight bearing or just confinement to a small cage or kennel. Pain management is also very important at this stage. Depending on the injuries, some pets can be comfortable on oral medications and be discharged from the hospital while awaiting definitive treatment while other pets may require intravenous pain medications in the hospital to keep them comfortable.

3. Definitive treatment.

The goal of definitive fracture treatment is to reconstruct the bone and return it to its normal position (reduction of the fracture) and then hold the bones pieces in this position (stabilization) for 6-12 weeks while the bone heals. Ultimately the method chosen to stabilize a fracture must be able to resist the forces that your pet would place on their normal bone during activity. These include bending, twisting, compression and pulling.

The final choice of the device(s) used to hold the fracture ends still will depend on many factors. Things that we will take into consideration include the location and shape of the broken pieces, the age of your pet, the health status of your pet, the activity level and expected level of function of your pet and the home environment. Once we have considered these factors, several options may be available to you.

Your final choice may take into account your finances as well as your ability to adhere to the post-operative care and recheck schedules. It is important that you discuss with your veterinarian any concerns you may have about the needed post-operative care and recheck the schedule during the initial evaluation. This will allow us to help you make the best decisions for your pet.

There are three main types of definitive treatment – external coaptation, external fixation and internal fixation. Sometimes, more than one type of definitive treatment may be needed for a single fracture (condition).

  • External coaptation is the use of a splint or cast inside of a bandage for definitive treatment of the fracture.
  • External fixation uses pins or wires that are placed through the skin and into the bone but protrude outside of the skin. The pins are connected by rigid bars or a hardened moldable putty outside of the skin to hold the bone pieces stable. The pins and bars are removed when the bone is healed leaving no remaining implants.
  • Internal fixation uses traditional bone plates, interlocking nails, screws, pins and orthopedic wire that are placed directly on or inside the bone. If no complications develop, these implants are left in place under the skin after the bone is healed.

Similarly, the goal with the treatment of joint injuries is to reconstruct or replace the supportive tissues to realign and stabilize this joint. Alternatively, some joint injuries are treated with temporary or permanent joint fusion (arthrodesis).

4. Post-operative care.

Bandage care: Some types of fractures need bandages, splints or casts for final treatment or for support following a surgical repair. These bandages are effective tools for fracture healing and pain control, but it is important to realize that they can also cause serious complications. Approximately 60% of dogs placed into a splint can develop some sort of wound under the splint. Careful monitoring and maintenance are required for safe bandage wear to help prevent and manage these complications.

To prevent problems, monitor the bandage daily and contact your veterinarian for a bandage change if any of the following are noted:

  • Swelling of the toes or of the leg above the bandage
  • Any soiling or wetness
  • Any change in position or shape of the bandage on limb
  • Any signs of excessive discomfort
  • Chewing of the leg/bandage
  • Any sores that develop at the top or bottom of the bandage
  • Any unusual or bad odors coming from the bandage

The bandage must be kept clean and dry. A plastic covering (IV fluid bag, baggie, bootie, Medipaw) MUST be placed over the bandage every time your pet goes outside to protect the bandage. Remove the plastic covering when your pet is inside.

You should not modify the bandage or splint in any way at home. Adding tape or other wraps can seriously compromise the safety of the bandage. If you notice problems at home, please return to your veterinarian for a bandage change.

Regular bandage changes will be scheduled during the splinting or casting period. It is important that you follow this schedule and discuss any needed alterations to the schedule with your veterinarian in advance.

Activity restriction: Confine your pet as directed by your veterinarian. This can be the hardest part of the recovery period and most pets will feel like fully using the leg long before the fracture has healed. Dogs can be confined to a crate, a playpen or a small room depending on the size of the dog. Dogs should be on a leash at all times when outside of this confined area, including when they are taken outdoors to use the restroom or to do physical therapy.

Cats are best confined in a large dog crate with enough room to place a litter box as well as food and water inside the crate. Cats can also be confined to a small room, but they are more likely to jump onto surfaces so all furniture must be removed and there should be no ledges that the cat can reach. It is important that you continue to restrict your pet throughout the healing period as directed to prevent implant and bandage complications that can be severe and, in some cases, can lead to additional surgical procedures.

Physical therapy: Physical therapy may be helpful or needed for some fracture or ligament/tendon injuries and repair options. Your veterinarian will talk with you about at-home or professional physical therapy options if they are indicated for your pet.