A craniolateral approach is performed. If further visualization is needed for fracture reduction, it is combined with a dorsal approach.
4. Surgical technique
Three small K-wires are used to carry out the fracture fixation.
K-wire insertion in the femoral neck
The K-wires are started at a point slightly distal and just cranial to the third trochanter. The wires are directed dorsally and slightly cranially to follow the direction of the femoral neck and avoid the trochanteric fossa.
Three K-wires are pre-inserted in the femoral neck. The K-wires are placed parallel to one another with the points visible at the fracture surface.
The wires can be driven in a retro or normograde fashion. Retrograde fashion ensures easier positioning of the pins within the femoral neck but requires a more aggressive exposure of the proximal femur to expose the fracture surface.
The use of an aiming device can also ensure accurate placement.
The fracture is reduced and secured with pointed reduction forceps. The K-wires are driven into the femoral head without penetrating the articular surface.
The lateral ends of the pins are bent and cut short.
Validation of fixation
Postoperative orthogonal radiographs are taken to assess fixation.
5. Case example
7 year old domestic shorthair cat with a B1 fracture from an unknown trauma.
The fracture was repaired using 3 parallel K-wires.
Postoperative radiographs at 1.5 months. One pin backed out after healing of the fracture.
Activity restriction is indicated until radiographs indicate bone healing of the fracture.
Phase 1: 1-3 day after surgery
Aim is to reduce the edema, inflammation and pain.
Integrative medical therapies, anti-inflammatory and analgesic medications.
Note: Nonsteroidal anti-inflammatory medications can be toxic in the cat and should only be used as labeled for the cat.
Phase 2: 4-10 days after surgery
Aim is to resolve the hematoma, edema and control pain, and prevent muscle contracture.
Anti-inflammatory (see nonsteroidal warning) and analgesic medications may still be needed. Rehabilitation and integrative medical therapies can be used.
Special attention should be given to patients less than 1 year of age with a femoral fracture. Rehabilitation is strongly recommended to help prevent quadriceps muscle contracture.
If the cat is not starting to use the limb within few days after surgery, a careful evaluation is recommended.
10-14 days after surgery the sutures are removed.
Radiographic assessment is performed every 4-8 weeks until bone healing is confirmed.
Implants may cause discomfort of the adjacent soft tissue. If this occurs, implants can be removed after bone healing is observed. In case of infection, implants must be removed after healing.
If there is no implant failure or infection, there is no need for implant removal.