You are in: eMedicine Specialties > Orthopedic Surgery > TRAUMA Supracondylar Femur FracturesArticle Last Updated: May 3, 2004AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Steven I Rabin, MD, Clinical Associate Professor, Loyola University Medical Center; Chair, Department of Orthopedic Surgery, Dreyer Medical Clinic Steven I Rabin is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Fracture Association, AO Foundation, and Orthopaedic Trauma Association Editors: James F Kellam, MD, Vice-Chair, Department of Orthopedic Surgery, Director of Orthopedic Trauma and Education, Carolinas Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Samuel Agnew, MD, FACS, Associate Professor, Departments of Orthopedic Surgery and Surgery, Chief of Orthopedic Trauma, University of Florida at Jacksonville; Consulting Surgeon, Department of Orthopedic Surgery, McLeod Regional Medical Center; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Jason H Calhoun, MD, FAAOS, Chairman, J Vernon Luck Distinguished Professor, Department of Orthopedic Surgery, University of Missouri Author and Editor Disclosure Synonyms and related keywords: thigh fracture, broken leg, traction INTRODUCTIONSection 2 of 12
  Supracondylar femur fractures require anatomically stable internal fixation for best results, which usually necessitates surgical treatment. These fractures usually occur in elderly patients with multiple comorbidities and osteoporotic bone; thus, a high rate of complications exists. Severely comminuted distal femur fractures are especially difficult fractures to treat properly (Johnson, 1988; Moore, 1987; Olerud, 1972; Pritchett, 1984; Rabin, 1995; Schatzker, 1979; Shahcheraghi, 1993; Wu, 1992; Zehntner, 1992). Obtaining adequate fixation may be technically challenging, especially when multiple fragments are present. Each device has limitations. Stable fixation depends on the exact placement of the hardware. If comminution and the fracture pattern compromise the use of an implant, the surgeon should be flexible and choose the device that fits best. History of the ProcedureHistorically, traction achieved adequate results for the treatment of supracondylar femur fractures (see Image 1); however, the outcomes probably would not be considered acceptable today. Maintaining leg length and preventing varus malalignment is difficult with traction. Although surgical risks were avoided, the patient was exposed to the risks of prolonged bedrest, including pulmonary complications, deep venous thrombosis, decubiti, disuse osteoporosis, and generalized muscle atrophy and deconditioning (Rabin, 1995). Previous surgical techniques and implants were inadequate to provide better results, but all current authors agree that best results are now achieved with operative methods (Shahcheraghi, 1993). ProblemThe goal in treating supracondylar femur fractures, as with any periarticular fracture in a weight-bearing bone, is restoration of a stable limb for functional pain-free ambulation. Initially, fixation and, finally, healing of the bone restores stability. Maintaining anatomic alignment and length and preventing stiffness restore function. Avoiding arthritis, which requires restoration of anatomic congruent joint surfaces and maintaining the normal mechanical axis of the limb, prevents pain. Complications are common and can be devastating (Rabin, 1995). Involvement of the articular surface demands a congruent anatomic reduction to prevent or minimize posttraumatic arthritis and provide bone stock for later knee replacement or fusion (Olerud, 1972; Schatzker, 1979). Severe comminution often requires fixation of multiple independent fragments with one device to minimize soft tissue damage (Johnson, 1988). The significant forces applied to this area, even during restricted patient activities, require a strong implant; however, fixation is difficult because of the wide canal, thin cortex, and relatively poor bone quality of the distal femur (Pritchett, 1984; Wu, 1992; Yang, 1990). Most surgical failures are caused by inadequate fixation of fracture fragments (Mize, 1982). No implant can stabilize every fracture type (Johnson, 1988); however, the device chosen must provide fixation rigid enough for early motion for best results (Halpenny, 1984; Newman, 1990; Schatzker, 1979). Supracondylar femur fractures that occur after total knee replacement are also more difficult to treat adequately because the knee replacement prosthesis can interfere with fixation implants. FrequencySupracondylar femur fractures are becoming more common as the population ages. EtiologySupracondylar femur fractures usually occur as a result of low-energy trauma in osteoporotic bone in elderly persons or high-energy trauma in young patients. Fractures proximal to knee replacements may be caused by notching of the anterior cortex when the surgeon placed the prosthesis or may be secondary to the stress riser effect of the interface between the rigid metal and soft bone. The treating physician must also be aware of the potential for pathologic fractures through metastatic lesions or primary bone tumors in this area. PathophysiologyThe distal femur is funnel shaped, and the area where the stronger diaphyseal bone meets the thinner and weaker metaphyseal bone is prone to fracture with direct or indirect trauma. ClinicalPatients present with pain, deformity, weakness, and inability to use the leg. Elderly patients usually have a history of a fall. Younger patients usually have had high-energy trauma. Especially for the younger patient, in whom significant soft tissue injury may also be present, careful assessment of the whole limb is required. Observe for compartment syndrome, vascular injury, and open wounds. Fractures in other areas need to be identified. INDICATIONSSection 3 of 12
Essentially all supracondylar femur fractures require operative intervention because of the severe potential risks of prolonged bedrest. RELEVANT ANATOMYSection 4 of 12
The distal femur is funnel shaped, and the surgeon needs to be aware of the shape of the bone when planning surgery so that the implant matches the bone. The approach to the thigh is a standard lateral one, with an incision through the fascia lata and access to the bone along the intermuscular septum under the vastus lateralis. The femoral artery is medial, and other neurovascular structures are posterior so they should not be encountered during surgery. CONTRAINDICATIONSSection 5 of 12
Patients in whom surgery is contraindicated include patients who are bedridden or nonambulatory with nondisplaced or minimally displaced fractures in which a brace may provide acceptable stability and alignment is not an issue. (Displaced unstable fractures in this group still may require surgery to improve nursing care, decrease pain, and prevent further soft tissue damage by mobile bone fragments.) Patients with severe life-threatening or other medical problems in which the risks of anesthesia are high may also be treated nonoperatively. WORKUPSection 6 of 12
Lab Studies
Imaging Studies
StagingNo specific staging system exists; however, the Association for the Study of Internal Fixation (AO-ASIF) and Orthopaedic Trauma Association (OTA) classification systems help the surgeon determine appropriate treatment options. AO-ASIF classification of supracondylar femur fractures is as follows:
TREATMENTSection 7 of 12
Medical therapyNo specific medical therapy for supracondylar femur fractures exists. If the patient is unable to tolerate surgery, temporary traction can be used to maintain length and alignment (see Image 1). For nondisplaced and stable fractures, bracing can provide enough stability to control pain and allow healing; however, bracing cannot control alignment or length because immobilizing the joint above and below is impossible. Surgical therapySurgical therapy requires reduction followed by fixation to maintain alignment. Options include external fixation or internal fixation. Internal fixation is with intramedullary devices (eg, flexible rods, more rigid retrograde or antegrade rods) or extramedullary plates and screws. Preoperative detailsThe AO-ASIF classification (also incorporated into the OTA classification) allows rational choice of treatment options (Miller, 1991). For extra-articular distal femur fractures (A1, A2, A3) or those with condylar fragmentation (C1, C2), the standard of fixation is dynamic condylar screw (DCS) or 95° degrees condylar blade plates (Benirschke, 1993; Schatzker, 1987; Tscherne, 1991) (see Images 2-3). For condylar fractures (B1, B2, B3) a 4.5-mm T buttress plate is recommended (Tscherne, 1991). Blade plates provide good rigid fixation, but the DCS is easier to insert, provides more interfragmentary compression across an intercondylar fracture, and corrects sagittal plane malalignment easier (Halpenny, 1984; Merchan, 1992; Newman, 1990; Yang, 1990; Mize, 1982; Pritchett, 1984; Giles, 1982; Tscherne, 1991; Schatzker, 1987; Zehntner, 1992). For very distal fractures, the condylar buttress plate, which can be contoured to fit the distal femur and is strong enough to allow early motion, is often recommended, although occasional T or straight plates can be used (Shelton, 1974; Zehntner, 1993; Benirschke, 1993; Schatzker, 1987; Sileski,1989; Zehntner, 1992) (see Image 4). Alternatively, intramedullary devices may be used, including standard locked nails; supracondylar and retrograde nails; or Rush, Ender, and Zickel rods (see Images 5-6) (Benirschke, 1993; Lucas, 1993; Kolmert, 1983; Shelbourne, 1982; Pryor, 1988; Tullock, 1988). The Wagner external fixator has also been used (Seligson, 1978). In severely contaminated open fractures, external fixation with minimal internal fixation may be an option (see Image 7) (Moore, 1987; Rabin, 1995; Seligson, 1978). These guidelines are useful in most supracondylar femur fractures; however, in severely comminuted complex (C3) fractures, rigid fixation of the multiple fragments may be challenging or impossible using standard implants. When using blade plates, DCS plates, supracondylar rods, or standard interlocking rods, the sites for distal screws must match the holes in the plate or rod and cannot be angled to find the best bone or avoid fracture lines. Multiple fragments anterior or posterior to the plane of the device cannot be secured. The condylar buttress plate is the usual option because no entry portal exists, screws can be angled, and it can be easily molded to fit (Tscherne, 1991). Even with this versatile plate, cases can occur in which most of the holes line up with fracture lines instead of intact bone, and the surgeon must be flexible when choosing the implant. Cobra plates, designed for hip fusions, are strong implants that can provide solid screws in available bone, or tibial buttress plates actually designed for the tibia have been used (see Images 8-9). These nonstandard plates can provide fixation in situations in which the standard implants do not fit the fracture pattern. Newer periarticular and fixed angled plates are replacing the condylar buttress plate and making the use of nonstandard implants less necessary. Fractures above a total knee replacement may require revision of the knee prosthesis, especially when it is loose. Options are more limited because the surgeon must plan to avoid the prosthesis when placing the fixation implants. A stemmed revision implant sometimes may be used to replace the joint while it stabilizes the fracture. Preoperative planning and templating of radiographs is essential to choose the appropriate implant to use for fixation and is best done before the procedure. Intraoperative detailsAll the devices used to stabilize supracondylar femur fractures require exact placement of hardware for optimal rigid fixation. If the coronal and sagittal fracture lines intersect at the entry point of the blade, lag screw, or intramedullary device, fixation is insecure. Placement of the blade within 1.5 cm of the articular surface is crucial (Schatzker, 1987; Mize, 1982). The lag screw of the DCS also requires exact placement 2.5 cm proximal to the articular surface (Markel, 1992; Giles, 1982). The screw is 0.5 mm thicker than the blade so it must be placed more proximally (Benirschke, 1993). With both DCS and blade plates, place one or more screws through the distal holes into the distal fragment for rotational stability (Schatzker, 1987). A standard interlocking nail is not feasible when a fracture is too distal ( <7 cm from the joint) or with displaced intra-articular fractures unless the joint can be reconstructed with cannulated lag screws because extensive intercondylar comminution prevents rigid fixation with these devices (Johnson, 1988; Newman, 1990; Wu, 1992; Zickel, 1986; Leung, 1991). Supracondylar nails also require restoration of the condyles before placing the nail (Lucas, 1993). Rush and Zickel devices must be inserted just proximal to the articular surface (Shelbourne, 1982; Pryor, 1988; Zickel, 1986). These flexible intramedullary devices may not provide adequate fixation (Johnson, 1988; Kolmert, 1983; Shelton, 1974; Wu, 1992; Zickel, 1986). Use of any plate for supracondylar femur fractures requires strict adherence to AO-ASIF techniques, including interfragmentary compression, indirect reduction, preservation of soft tissue attachments, and bone grafting. The surgeon must be aware of the trapezoidal shape of the distal femur and align the plate properly. Plates that do not match the metaphyseal flare must be molded to fit. When fixing these complex fractures, the surgeon chooses a device that fits. The surgeon should not try to make the fracture fit the device. Postoperative detailsDuring fixation of supracondylar femur fractures, the surgeon must assess the stability of fixation and quality of the bone. If the fixation is solid and bone quality good, some patients can be allowed early weight bearing and motion, especially when intramedullary fixation is used. If bone quality is good but not enough to allow early weight bearing, the patient may be placed in a hinged knee brace to allow early motion but kept off full weight bearing until radiographs show bone healing (at about 12 wk). If bone quality is poor, more rigid splinting may be required for about 6 weeks and then switched to a hinged brace. Postoperative physical therapy is usually required. Follow-upPatients need to be monitored until the bone is healed. COMPLICATIONSSection 8 of 12
Complications of supracondylar femur fractures include nonunion, often with hardware removal, loss of alignment (malunion), infection, and medical complications (eg, thromboembolic disease). OUTCOME AND PROGNOSISSection 9 of 12
With stable fixation, anatomic alignment, and restoration of intra-articular congruency, most patients do well. The more comminuted the fracture and the poorer the quality of bone, fixation, or reduction, the worse the prognosis. Severe comminuted type C3 fractures are expected to develop significant stiffness and posttraumatic arthritis. Patients with open fractures fair worse than closed fractures. FUTURE AND CONTROVERSIESSection 10 of 12
Improved results are being obtained and expected with newer plate designs and techniques, including bridge plating, minimally invasive plating, specially designed periarticular plates, and fixed-angle screw plates. Although these newer plating techniques truly cannot be considered future developments because they are currently being used, they are expected to have more widespread use as surgeons gain experience with their use.
A helpful point to remember is to use the device that fits the fracture and use careful surgical technique to obtain best results. Be flexible but plan carefully. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Supracondylar Femur Fractures excerpt Article Last Updated: May 3, 2004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
