Summary of Distal Femur Fractures
Distal femur fractures are severe injuries that can be technically challenging to operatively treat. Although they account for less than 1% of all fractures and between 3% и 6% of femur fractures, their incidence is likely to increase with
the rising geriatric populations and the increasing number of peri-prosthetic injuries.In young individuals, they typically result from high-energy trauma such as motor vehicle collisions; in elderly patients, they more often occur due to low-energy falls, frequently exacerbated by osteoporosis.
Historically managed with conservative methods such as traction and bracing, treatment paradigms have evolved considerably with the advancement of surgical techniques and implant designs. Today, operative management is the mainstay, aiming to restore limb alignment, promote fracture healing, and enable early mobilization. Selecting the appropriate surgical approach requires consideration of the fracture pattern, bone quality, patient comorbidities, and surgeon expertise.
Surgical Management
1.Внешний фиксатор
External fixation is typically used as a temporary stabilization method, especially in cases involving open fractures, severe soft tissue damage, comminution, vascular injury, or polytrauma. It can be applied using monolateral frames or circular (ring) fixators, often bridging the knee joint.
Advantages of external fixation include:
A.Minimally invasive application
B.Preservation of local blood supply
C.Shorter operative time and less intraoperative blood loss
However, it is not ideal for long-term use due to:
A.Risk of pin-site infection
B.Limited mechanical stability for complex articular fractures
C.Restricted joint mobility if spanning the knee
It serves primarily as a damage-control strategy before definitive fixation.
2. Conventional Plate
Conventional plate systems (such as dynamic condylar screws and blade plates) were once the standard for managing distal femur fractures. Open Reduction and Internal Fixation (ORIF) with conventional plates provides rigid stabilization and is particularly suited for simple, non-comminuted fracture patterns.
Strengths:
A.Precise anatomical reconstruction
B.Good biomechanical support in selected cases
Limitations:
A.Requires extensive soft tissue dissection
B.High risk of periosteal devascularization
C.Increased rates of infection, несращение, and implant failure
As a result, newer biologic fixation strategies have largely replaced this technique.
3. Locking Plate
Locking compression plates (LCPs) represent a major advancement in fixation technology, particularly beneficial in osteoporotic bone and metaphyseal comminution. Unlike conventional plates, locking plates create a fixed-angle construct between the screw and plate, providing angular stability and eliminating the need for bone-plate compression.
Advantages:
A.Preserves periosteal blood supply
B.Effective in osteoporotic or comminuted fractures
C.Minimally invasive surgical techniques possible
Challenges:
A.Increased implant stiffness may hinder callus formation B.Risk of stress shielding and delayed healing
C.Requires careful planning regarding plate length and screw density
To mitigate complications, long plates with fewer screws and flexible materials (e.g., titanium) are often preferred.
4. Anterograde Intramedullary Nailing
Anterograde nailing is most appropriate for diaphyseal or metaphyseal fractures of the distal femur that do not involve the joint surface. In this technique, the nail is inserted proximally through the femoral canal.
Pros:
A.Minimally invasive
B.Reduced soft tissue disruption
C.Good axial and torsional stability
Cons:
A.Not suitable for complex intra-articular fractures
B.May cause hip joint irritation or trochanteric pain
C.Challenging in obese patients or with preexisting hip implants
It remains a valid option in selected extra-articular fracture patterns.
5. Retrograde Intramedullary Nailing
Retrograde femoral nailing is inserted through the intercondylar notch of the distal femur and is widely used for both extra-articular and some simple intra-articular fractures.
Benefits: A.Single surgical approach for polytrauma patients (e.g., floating knee)
B.Less invasive than plating
C.Enables early weight bearing
Indications include:
A.Extra-articular or simple articular fractures
B.Cases with concurrent ipsilateral tibial fractures
C.Peri-prosthetic fractures below well-fixed total hip arthroplasties
However, care must be taken to preserve the knee joint cartilage during insertion, and it is contraindicated in highly comminuted intra-articular fractures.
6. Total Knee Arthroplasty (TKA)
In elderly patients with poor bone stock, severe comminution, or pre-existing arthritis, distal femoral replacement or total knee arthroplasty may be a definitive treatment option. This approach replaces the distal femur with a prosthesis, offering immediate joint stability and early mobilization.
Advantages:
A.Allows early full weight-bearing
B.Avoids prolonged immobilization
C.Addresses preexisting osteoarthritis
Drawbacks:
A.Technically demanding
B.Higher cost and implant-specific complications
C.Not suitable for younger or more active individuals
TKA is increasingly being used in fragility fractures where internal fixation is unlikely to succeed.
Conclusion
The management of distal femur fractures requires a nuanced understanding of fracture mechanics, patient physiology, and surgical expertise. While external fixation serves as a valuable temporizing measure, definitive treatment typically involves locking plate fixation or intramedullary nailing. Each technique offers unique advantages and limitations that must be carefully matched to the clinical scenario. In elderly patients or those with unsalvageable fractures, total knee arthroplasty remains a viable and often preferable alternative.
An individualized, evidence-based approach ensures optimal functional outcomes, minimizes complications, and facilitates early return to mobility for patients with distal femoral fractures.