This document discusses distal femur fractures, which account for 7% of all femur fractures. It notes they have a bimodal distribution between high-energy injuries in youth and low-energy fractures in the elderly. Key associated injuries include open fractures, vascular injuries, knee ligament injuries, and other fractures. Treatment depends on the fracture type but aims to restore alignment and stability while minimizing soft tissue disruption. Complications can include malalignment, nonunion, knee stiffness, infection, and hardware problems.

3. • Account for 7% of all femur
• Fractures Bimodal distribution: High-energy
injuries in the young, low-energy in the
elderly
Introduction

4. • Shaft of femur aligned
with anterior half of
lateral condyle
• Anatomic axis 6-
7°valgus (range 2-10°)
• Sectioned axially, distal
femur is trapezoidal
Ramifications for:
Implant placement
Screw prominence

6. Injury Considerations
Associated injuries
– Open fracture (5-10%)
– Vascular Injuries
– Knee ligament injury (up to
20% of cases)
– Tibial plateau fracture
– Patella fracture
– Acetabulum fracture
– Femoral neck fracture
– Femoral shaft fracture

7. • Indications for arteriography with intra-
arterial injection or CT angiography include an
absent or diminished pulse, expanding
hematoma, diminished ankle-ankle index,
bruit, persistent arterial bleeding, and injury
to anatomically related nerves.

8. • If arterial compromise is severe or the time
elapsed from injury is more than 6 hours,
reestablishment of circulation takes priority.
Consideration should be given to rapid
application of an external fixator to restore
length and provide stability before arterial
reconstruction. A temporary vascular shunt
followed by definitive vascular repair may be
useful.

9. • Fasciotomy of the lower leg should be
considered in all patients with ischemia time
exceeding 6 hours and those with tenseness
of the fascial compartments after reperfusion
or extensive soft tissue injuries.

10. • In patients with massive open wounds with
vascular injury (type IIIC) or those in extremis,
primary amputation may be indicated. This is
particularly true if the injury is associated with
sciatic or posterior tibial nerve disruption.

11. Periprosthetic Distal Femur Fractures
Risk factors for fractures include osteopenia,
rheumatoid arthritis, prolonged corticosteroid
therapy, anterior notching of the femoral
cortex, and revision arthroplasty.

19. • Although treatment must be individualized for each patient, no more than
7 degrees of malalignment in the coronal plane (mediolateral) should be
accepted. Whenever possible, malalignment in the sagittal plane
(anteroposterior) should not exceed 7 to 10 degrees. Limb shortening of
1 to 1.5 cm usually does not compromise the functional result and can be
addressed with a shoe lift, if necessary. Except in unusual circumstances,
articular incongruity of more than 2 mm should not be accepted. While
in traction, patients should be encouraged to attempt limited knee
flexion. When the acute soft tissue swelling has subsided, tenderness at
the fracture site is minimal, and x-rays show early callus formation, the
patient can be transferred to a fracture brace. This can be made from
plaster, fiberglass, or polyethylene and should allow full knee motion. A
fracture brace is usually placed between 3 and 6 weeks after injury,
correlating clinical signs and symptoms and radiographic evidence of callus
formation. It should be applied with the limb in extension, external
rotation, and slight valgus.

24. • Types of Fixation
– Lateral pre-contoured plates
May be used for most fracture patterns
– Retrograde intramedullary nail
Most common for AO/OTA type A fractures
Some simple intra-articular patterns (AO/OTA type C1 & C2)
• Dynamic condylar screw/ Angled blade plate
• Buried screw fixation for Hoffa fractures

25. Differing designs of condylar fixation for plates
used for repairing distal femur fractures.
• From left to right, the 95-degree blade plate,
DCS, modern fixed-angle locking plate, and
variable angle locking plate.

26. • Intramedullary nail Minimizes
disruption of soft tissues
• Improved designs (multiple distal screw
options and ability to lock distal screws
to the nail) have expanded their
indications
• Retrograde nail should extend to the
level of the lesser trochanter, or at least
allow two proximal interlocking screws
• Antegrade nails may be an option for
high supracondylar fractures or
segmental fractures
• Reduce fracture prior to reaming

28. Authors' preferred treatment for
distal femur fractures

30. Common Adverse Outcomes and
Complications
• Malalignment/malunion
• Nonunion
• Knee stiffness
• Infection
• Hardware-related problems
• Posttraumatic arthritis