Key Points
Bone growth comes from a soft layer of tissue at the ends of the bones called growth plates
This region of the bone is susceptible to developing a fracture in puppies and kittens
This type of fracture usually requires surgery for a good outcome, but in some cases can be managed conservatively
Initial visit- downloadable forms/information for clients:
History sheet - Client initial consultation history
Client education handout - tibial fractures
Discharge instructions after surgery - dog
Discharge instructions for postop care - cat
2-week recheck visit - downloadable forms/information for clients:
History form - 2 week postop (Telemedicine evaluation) - dog and cat
Postop care instructions 2-week fracture repair recheck - cat
Postop care instructions 2-week fracture repair recheck - dog
6-week recheck visit - downloadable forms/information for clients:
History form 8-week fracture recheck (in hospital) - dog and cat
Postop care instructions 6 week fracture recheck - dog
Postop care instructions 6 week fracture recheck - cat
Downloadable forms for referring veterinarians:
Anatomy
The hind limb has two bones between the knee and the ankle joint: the tibia and fibula bones. The tibia is the larger weight-supporting bone, whereas the fibula bone supports minimal weight. Puppies have much softer bones than adults; therefore more fractures occur in younger dogs. The top and bottom of the tibia bones have a very soft region called the growth plate from which the bone grows. This area is particularly prone to developing a fracture until the growth plate has closed (fused) at 8 to 10 months of age. This type of fracture is uncommon in cats.
Cause of fracture
The patellar ligament is attached to the tibial crest. A tractional force placed on the tibial crest by the pull of the quadriceps muscle can result in a fracture through the growth plate of the tibial crest.
Surgery
For most fractures of the growth plate of the tibia, one or more pins and sometimes a tension band cerclage wire are used to repair the fracture. There are two approaches to repair tibial crest fractures: minimally invasive surgery and open surgical incision. The minimally invasive surgery involves the use of intraoperative radiography to place pins through the skin. The open surgical approach involves making an incision large enough to expose the tibial crest and pin it in place. With this approach a tension band cerclage wire can be applied for additional fixation of the bone in place. In our experience, both minimally invasive surgery and open surgery have the same success rate. Surgical repair of a displaced tibial fracture is essential, due to continued displacement of the bone by the pull of the quadriceps muscles/patellar ligament. Minimally displaced tibial crest fractures commonly will become significantly displaced. However, with strict cage rest, a minimally displaced tibial crest fracture can heal. Splints applied to the limb commonly fail to provide stability to the fracture. In these conservatively managed cases, weekly radiographs should be made (until fracture heals) and if there is displacement of the tibial crest fracture, surgery should be completed.
Surgery is recommended with placement of at least one or more pins (see images right).
Aftercare
After surgery, you can continue to give your pet a prescribed pain reliever to minimize discomfort. The surgeon will monitor the healing process with at least two follow-up exams. The first is scheduled at two weeks after the surgery. During the second exam, at about six weeks after the surgery (depending on the age of the pet), radiographs will be made to evaluate the healing bone.
Prognosis
Surgical repair of a fractured tibial crest offers multiple benefits including a faster recovery, better chance to return to athletic activity and better range of motion of the knee joint. Uncommon complications include infection, shifting of the tibial crest, breakage of the metal pins or wires. Formation of a fluid bubble (seroma) of over the end of the pin(s) may develop; if the seroma does not resolve after fracture healing has taken place, then the pins can be removed. If partial closure of front side of the growth plate of the tibial plateau occurs, the tibial plateau will flattened which will have a protective effect against cranial cruciate ligament tear.