Background
Open reduction and internal fixation (ORIF) is a commonly used treatment for fractures throughout the body, including the distal femur. [1] Supracondylar fractures of the femur account for approximately 7% of all femur fractures. They occur just proximal to the knee joint, in the terminal 9 cm of the femur between the metaphyseal-diaphyseal junction and the femoral condyles. [2]
Supracondylar femur fractures have a bimodal distribution within the population. They present in younger patients as a result of high-energy injuries (eg, from motor vehicle collisions or falls from height). In elderly patients, these fractures are often due to low-energy injury mechanisms (eg, simple falls) because of underlying osteoporosis. Supracondylar femur fractures may propagate proximally into the diaphysis or extend distally in the knee joint. Regardless of injury mechanism, supracondylar femur fractures often require surgical treatment for the restoration of limb alignment and fracture stability. [3]
Indications
Historically, supracondylar femur fractures were treated with skeletal traction. However, results were poor and complications such as angular deformity, knee stiffness, and delayed mobilization persisted after nonoperative treatment. With advancement in orthopedic implant technology, current consensus among orthopedic surgeons is to treat supracondylar femur fractures surgically.
Indications for ORIF include the following:
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Open fractures
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Fractures associated with neurovascular compromise
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All displaced fractures
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Ipsilateral lower-extremity fractures
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Irreducible fractures
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Pathologic fractures
Contraindications
Patients who are hemodynamically unstable and polytrauma patients may benefit from provisional stabilization of the fracture instead of ORIF. Infections or medical conditions that could pose a life-threatening surgical or anesthetic risk are also contraindications.
There are a few contraindications for a dynamic condylar screw. The condylar screw system is contraindicated when there is a low transcondylar fracture, a coronal fracture, or significant intraarticular comminution.
The bridge plating technique is not appropriate if the soft tissue envelope is not intact (as in severe open fractures), if marked osteoporosis is present, or if there is significant medial bone loss. Under such circumstances, supplemental fixation of the metaphyseal segment is necessary, and a bone graft should be applied to the medial defect.
Technical Considerations
Best practices
In preparing for surgical treatment of a supracondylar femur fracture, it is essential to have the necessary tools and equipment in place. It is also essential to have a preoperative template in hand as to what the step-by-step approach to the case will be.
Procedural planning
The Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF) classification designates the supracondylar femoral fracture as type A. [2] Type A is further divided into subtypes: subtype A1 is a simple fracture, subtype A2 is a metaphyseal wedge fracture, and subtype A3 is a comminuted metaphyseal fracture.
Options for the surgical treatment of supracondylar femoral fractures include plates, intramedullary nails, external fixators, and total knee arthroplasty. The technique used is determined by fracture pattern, bone quality, the hemodynamic stability of the patient, and the skill and experience of the surgeon.
The 95º angled blade plate is a one-piece, fixed-angle device with a blade distally that is inserted into the femoral condyles. The use of blade plates has been falling out of favor, but it is still an essential skill to have as an orthopedic surgeon.
Condylar screw systems are technically easier to use than the angled blade plate. Sagittal plane adjustments can be made in the plate position, which is not possible with the blade plate. Also, the condylar screw provides interfragmentary compression for fractures with an intercondylar split.
The condylar buttress plate is a broad plate with a cloverleaf distal portion that is contoured to fit the lateral aspect of the distal femur. It may be used for the fixation of minimally displaced fractures, but is most useful in fractures with articular extension in the sagittal and coronal planes. It can also be used as an intraoperative backup device when difficulties are encountered with the angled blade plate or condylar screw system.
The less invasive stabilization system (LISS) from the AO Foundation uses a locking plate and screw construct, which preserves the periosteal blood supply to the fracture. It is used in a similar technique as the buttress plate. The LISS plate is more often used in cases of osteoporotic bone. [4]
Outcomes
Darrith et al compared the outcomes of 50 displaced periprosthetic distal femur fractures treated with ORIF with those of 22 treated with distal femoral replacement (DFR) using multivariate regression analysis. The Knee Society Functional Scores were higher in the ORIF group, but the total incidence of revision was also higher. Additionally, more patients in the ORIF group required repeat revisions. [5]
Ruder et al reported no difference in mortality, complications, discharge disposition, or ambulatory status and living situation at 1 year between ORIF-treated and DFR-treated periprosthetic distal femur fractures. [6]
