Femur fractures Flashcards
Capital Physeal Fractures
Frog leg radiographs
Salter harris type 1 or 2, but physeal closure is expected. Increased incidence in cats due to early spay and neuter
Treatment: Multiple kirschner wires, lag screw fixation, femoral head and neck excision
Capital Physeal Fractures treatment
Kirschner wires inserted at the 3rd trochanter- must reflect the vastus lateralis muscle. Head and neck slightly anteverted- kirschner directed caudal to cranial. Pre-place wires prior to definitive reduction
Physis has an L shape. Do not penetrate the articular cartilage.
Thickest bone in the epiphysis is located dorsolateral to the corner
Poor results in dogs <4 months or concurrent acetabular fractures.
Blood supply to the epiphysis is extraosseous.
Femoral neck fractures
Occur in skeletally mature dogs and cats.
Results in craniodorsal displacement of the greater trochanter.
Treated with open reduction and internal fixation or femoral head and neck excision
Treatment: Open reduction via a craniolateral approach to the coxofemoral joint with lag screw fixation and an anti-rotational kirschner wire.
Diaphyseal femur fractures
Unstable fractures managed via open reduction and internal fixation. Lateral approach.
Incise fascia lata cranial to the biceps femoris mm, extend the incision proximally caudal to the tensor fasciae latae mm
Adductor magnus mm has strong periosteal attachment to the femoral diaphysis
Adductur magnus insertion point is a good landmark for assessing rotational alignment
Diaphyseal fracture stabilization
IM pin Interlocking nail stabilization Bone plating Plate-rod stabilization External skeletal fixation Selection depends on: Signalment and temperament of the patient Location and configuration of the fracture Conurrent injuries Availability of implants and systems Experience of the surgeon money
Diaphyseal fracture- dog
Femur conformation is less than ideal for fracture repair.
Diaphysis comes to an ishmus at the junction of the proximal and middle thirds.
Most dogs have caudal angulation of the distal femur
Diaphyseal fracture- cat
Conformation is better than dogs for implant application.
Thin cortical bone subject to fissuring and fracture
Good at bending appropriately sized implants
IM pin fixation- Three point fixation
- Proximal epiphyseal/ metaphyseal cancellous bone
- Endosteal surface of diaphysis
- Distal epiphyseal/ metaphyseal cancellous bone
IM pin placement
Preferably normograde- craniolateral aspect of trochanteric fossa. Avoid the sciatic nn
“over reduction”- allows better distal purchase. Prevents anatomic reconstruction
Tie in fixator constructs allows improved biomechanics and prevents pin migration
External skeletal fixation
Rarely used as primary fixation.
Limited effectively to type 1 configurations on femur diaphyseal fractures.
Consider tie ins
Interlocking nail stabilization
Controls bending, rotational, and axial forces.
Situated in the central mechanical axis.
Placed using a closed or open reduction.
Plating diaphyseal fractures
Can provide rigid internal fixation. Allows for immediate weight bearing and rapid return to function. Limited post op patient care
Plate functioning as a neutralization plate
Neutralizing the force along the bone away from the fracture.
Bridging- not reconstruction because highly comminuted. More worried about spatial alignment
Plate- rod constructs
IM pin should occupy 35-40% of the diameter of the medullary cavoty
Minimum of 3 monocortical screws and 1 bicortical screw in each fracture segment
Distal femoral physeal fracture
Salter-harris type 1 or , but physeal closure expected.
Typically limb shortening is not an issue if >4 months old.
Anatomic reduction provides substantial stability
Treatment: Use tibial plateau to push condyle into anatomic reduction.
Direct kirchner wires toward the center of the forceps
