Fracture of the Tibia and Fibula in Cats
Overview of Feline Tibia and Fibula Fractures
The tibia and fibula are the two bones that make up the lower rear leg. Fractures of these bones are commonly encountered in veterinary medicine. Because of the conformation of the lower rear leg, both bones, the tibia and fibula, usually fracture at the same time.
Below is an overview of Tibia and Fibula Fractures in Cats followed by detailed information on the diagnosis and treatment of this condition.
These fractures are usually the result of trauma, but can be caused by disease of the bone itself. They can occur in an immature bone (one that has not finished growing), or in a mature one, can be “open” or “closed” and can be “simple” or “comminuted.” They can also involve either the tarsus (ankle) or knee joints.
Depending on the nature of the fracture and the age of the animal, different methods of repair may be indicated for each situation. Tibia and fibula fractures can have serious complications if not repaired, or if the repair fails, and can result in developmental abnormalities of the leg if the animal is immature when the injury occurred.
What to Watch For
- Abnormally positioned leg
- Pain or inability to move
Diagnosis of Tibia and Fibula Fractures in Cats
A thorough physical examination and medical history are important in any illness or injury. Based on the results of the physical examination, additional tests may be recommended.. No laboratory tests are required to make the diagnosis
- Chest radiographs
- Complete orthopedic examination
- Radiographs of the affected leg
Treatment of Tibia and Fibula Fractures in Cats
Emergency care for concurrent problems caused by the trauma is the most important part of treatment. After stabilization, additional treatment may include:
- Treatment of concurrent soft-tissue injuries
- Some fractures of the forearm can be managed with a cast or splint
- Some tibia and fibula fractures require anesthesia and surgical stabilization of the bone fragments for the best results
- Injectable analgesics (pain medications) are given to the animal while being treated in the hospital and may be continued orally once discharged from the hospital
Home Care and Prevention
Bring the animal to the veterinarian as soon as possible after any trauma for immediate attention. Try to prevent your pet from walking or moving too much. Prompt veterinary treatment is recommended. Do not attempt to place a splint or bandage on the leg unless profuse bleeding is occurring.
After surgical repair of the fracture, the animal must be kept restricted from activity for several weeks and the skin incision should be monitored while healing. A recheck with your veterinarian will occur in several weeks to evaluate how the bones are healing (with new radiographs), to monitor the animal’s progress, and to make sure it is safe to increase the animal’s activity level.
Many traumatic events are true accidents and thus unavoidable. Avoid the chance for motor vehicle trauma by keeping your cat indoors.
In-depth Information on Tibia and Fibula Fractures in Cats
Tibia and fibula fractures are commonly seen in veterinary trauma patients,usually as a result of motor vehicle trauma. These injured dogs tend to be young, non-neutered males who roam away from home and get hit by a car. Animals of both sexes and of any age are susceptible to this type of trauma if not kept restrained.
Dogs can develop non-traumatic fractures of the tibia or fibula when certain disease conditions exist. These fractures, also known as “pathologic fractures,” can occur if the animal is malnourished, has a systemic illness such as kidney disease, has an endocrine disorder such as hyperparathyroidism, has a bone infection (osteomyelitis), or has cancer of the bone.
Immature bones have growth plates (physes) that are still “open” and growing. These regions of the young bone are generally weaker than the bone that has already been created. The energy of a trauma often results in fracture at these parts of the immature bone and can lead to premature “closure” of the physes resulting in abnormal growth at either end of the bone.
Frequently encountered fractures of the immature tibia include:
- Fracture of the tibial tuberosity (boney prominence on which the tendon of the quadriceps muscle attaches)
- Physeal fractures at the end of the bone near the stifle (proximal physis)
- Physeal fractures at the end of the bone near the hock (ankle joint or tarsus)
- Fractures of the middle of the bone (diaphysis)
Fractures of the mature tibia and fibula usually occur in the midportion of the bones. Joint fractures involving the stifle or hock can occur at either end of the bones.
Fractures of the diaphysis of the tibia/fibula can be classified as “open” or “closed” depending on whether the skin surface has been damaged during the injury. Open fractures are common with these fractures because there is not much soft tissue coverage in this portion of the leg. Open fractures have a greater chance of getting infected and may have more complications than closed fractures.
As with all fractures, fractures of the tibia/fibula can also be classified as “simple,” if each bone breaks into two pieces, or “comminuted,” if there are multiple pieces.
Each case of tibia/fibula fracture needs to be evaluated in its entirety (age of animal, severity of the fracture, experience of the surgeon, and financial concerns of the owner) to determine the most appropriate and best form of treatment.
Inappropriate case management, inadequate surgical stabilization, or poor aftercare can lead to complications such as non-unions (fractures that will not heal), malunions (fractures that heal in an abnormal direction or orientation), osteomyelitis (bone infection), arthritis, or a non-functional leg.
A thorough physical examination is very important to make sure your pet is not showing signs of hypovolemic shock secondary to the trauma or blood loss. It is also important to make certain that there are no other injuries present. No laboratory tests are required to make the diagnosis, but additional tests may include:
- Thoracic radiographs (chest X-rays). Chest trauma, in the form of pulmonary contusions (bruising) or pneumothorax (collapsed lung lobes secondary to free air within the chest cavity), must be ruled-out with chest radiographs prior to anesthesia to repair the leg.
- Complete orthopedic examination. A complete orthopedic examination must be performed to look for the cause of the non-weight bearing lameness as well as possible injuries in other bones or joints. Examination involves palpation of all of the bones and joints of each leg for signs of pain or abnormal motion within a bone or joint as well as an assessment of the neurological status of each leg. The thorough orthopedic examination is especially important for an animal that is unable or unwilling to get up and move. Specific palpation of the hind leg and finding swelling, bruising, and crepitation (abnormal “crunchy” feeling with motion) between the stifle and hock can be highly suggestive of fractures of the tibia and fibula.
- Radiographs of the leg. Two radiographic view of the animal’s lower leg are used to confirm the diagnosis of tibia/fibula fracture. Based on the location and severity of the fracture, a more informed discussion with the owner can occur regarding potential treatments, prognosis and costs.
Emergency care for concurrent problems is paramount. Shock is a frequent result of major trauma and must be treated quickly. Treatment for shock involves intravenous fluid administration to maintain blood pressure and adequate oxygen delivery to the body. Injury to the lungs and chest cavity are also commonly seen after major trauma and may require supplemental oxygenation or removal of free air (pneumothorax) from around the lungs. After stabilization, additional treatment may include:
- Soft-tissue injuries must be addressed in order to minimize the chance for the development of wound infections. Lacerations and other open wounds or open fractures must be cleaned of debris and covered or closed to minimize infections.
- In the interim between treating the emergency patient and surgical repair of the tibia/fibula fracture, all of the orthopedic injuries that have been found should be addressed with splints and/or pain medications to keep the animal comfortable until the fracture can be properly addressed.
- Depending on the specific fracture type, location, and age of the animal, tibia/fibula fractures may be managed in one of two ways. Some of these fractures may not need surgical stabilization. Minimally displaced fractures that involve the middle or distal end of the bones might fit into this category.
- Tibia and fibula fractures may be surgically repaired in many different ways based upon the specific fracture type, location, and age of the animal. Surgical options include: bone plates and screws, pins and wires, and external fixators (pins holding the bone fragments stable through holes in the skin connected on the outside, like a scaffolding). These options can be used individually or in combinations to provide stability to the bone fragments while they heal.
- Tibia and fibula fractures, as well as any other traumatic injuries that the animal might have, are painful and the animal will be given analgesics before and after surgery.
Follow-up Care of Tibia and Fibula Fractures in Cats
If a cast or splint is used to immobilize the leg, strictly confine your cat to allow the leg to heal and prevent excessive pain. Because the bone fragments are not as well stabilized when this course of treatment is followed (compared with surgical fixation), excessive motion or activity can prevent the fracture from healing at all or cause it to heal improperly.
After surgery and discharge from the hospital, the animal must be restricted from activity to allow the fracture to heal properly. Activity must be restricted for several weeks after surgery. The duration will vary depending on the severity of the injury, the type of fixation that was used, and the age of the animal. Restricted activity means that the cat should be kept confined to a carrier, crate, or small room whenever he cannot be supervised, the cat cannot play or rough-house (even if he appears to be feeling well) and the use of stairs should be limited.
Cats whose fracture was repaired with an external fixation device will have pins exiting the skin. The “pin tracts” should be monitored daily for excessive swelling or discharge. Some discharge is normal and any crusty build-up that occurs at these sites can be gently cleaned with warm water.
Analgesics (pain medications) or anti-inflammatories should be given as directed by the veterinarian. Analgesics, such as butorphanol (Torbugesic®) can cause sedation, and anti-inflammatories, such as aspirin or carprofen (Rimadyl®), can cause an upset stomach.
The skin incision needs to be monitored daily for signs of excessive swelling or discharge. These can indicate problems with the incision or possibly infection. If at any point prior to the recheck radiographs being taken, the cat stops using the leg again after some improvement following surgery, there could be a problem.
Several weeks after surgery, the leg will need to be radiographed again to make sure the bone is healing properly. If the healing has occurred as expected, the external fixator, if present, will be removed and the cat’s activity level will be allowed to increase slowly back up to normal over the next few weeks.
In general, any other implants that were used in the repair will be left in place unless they cause a problem at some point in the future. Potential problems can include migration (movement) or infection of the implants.