Distal Femur Fractures

Overview Evaluation Planning Surgery Options Techniques

Distal Femur Fractures Assess fracture/patient “Personality of the fracture” Other patient issues (e.g. polytrauma) Plan your surgery Implants, positioning, technique Reduce fracture Stabilize fracture Rehabilitation

Articular Fractures Overriding principles: Anatomic reduction of joint surfaces Reduce articular surface to shaft with appropriate length, alignment, rotation Stable fixation with safe implant placement and minimal biological insult Allows for early motion of the joint and early rehabilitation Principles similar for all articular fractures

Evaluation of Distal Femur Fractures Plain radiographs AP/lateral knee AP/lateral femur AP/lateral contralateral distal femur for planning Consider traction views or obliques CT Scan?

Evaluation of Distal Femur Fractures CT scan – gives details about articular surface involvement Wait for traction if ex-fix planned

Evaluation of Distal Femur Fractures Don’t forget the Hoffa fragment! 38% of supracondylar/intercondylar distal femur fractures have a coronal plane fracture (Nork et al, J Orthop Trauma, 87:564, 2005) Most precisely diagnosed via CT scanning

Classification Schemes - Caution Classification schemes are mediocre at best A good classification: Describes the fracture pattern well Describes the prognosis/outcome for the patient Is reproducible for multiple fractures for the same practitioner Is reproducible across multiple practitioners Guides treatment Few classification schemes do all of this well

External Fixation? Valuable for tibial plateau fractures and pilon fractures for temporary stabilization to allow for soft tissue recovery Distal femur fractures can often be fixed definitively without delay, unless… Patient condition precludes long procedure or definitive fixation Non-patient-specific factors (OR availability, etc.)

External Fixation? Spanning knee external fixation Allows for temporary stabilization of fracture if delayed reconstruction is necessary External fixator as a reduction aid at time of definitive reconstruction Keep pins out of planned surgical field!

Planning Definitive Reconstruction Avoid notch and concomitant injury to cruciate ligaments Avoid penetration of medial cortex with anterior screws X X

Planning Definitive Reconstruction – Posterior Condylar Alignment with Shaft Posterior condyles project POSTERIORLY with regard to femoral shaft! Don’t do this!

Planning Definitive Reconstruction – Distal Femoral Valgus 9° valgus anatomic axis for distal femur

Planning Definitive Reconstruction – Deforming Forces Short and extended is no way to go through life, son Hamstrings Shorten Gastrocnemius Extends

“Method of Attack” Reduce articular surfaces first Direct reduction techniques Secure fixation of articular surfaces Interfragmentary screws Restore continuity of articular block with shaft Indirect reduction techniques

Internal Fixation Options Condylar buttress plates Fixed-angle devices Blade plate Dynamic Condylar Screw (“DCS”) Retrograde intramedullary nail Locked plates All implants can work if utilized properly

Prior to Applying Implants… Reduce the fracture!

Surgical Technique Internal fixation implants do NOT reduce the fracture (although they may aid reduction) The surgeon reduces the fracture Distal femur extended

Indirect Reduction Not for articular surfaces Direct visualization and reduction Preserves soft-tissue envelope around metadiaphyseal fracture lines Achieve restoration of length, alignment, and rotation via traction and manipulation utilizing reduction aids that do not strip soft tissues around the fracture site

Respect the Biology! Indirect reduction techniques: External fixator Femoral distractor “Joysticks” Percutaneous clamps Bumps

Indirect Reduction Aids BEFORE AFTER BUMP

Respect the Biology – Indirect Reduction Limit soft tissue dissection Indirect reduction techniques Submuscular plate application without extensive stripping Preserve periosteal blood supply when able

Which Implant? Condylar buttress plate Fixed-angle device Blade plate Dynamic Condylar Screw (“DCS”) Retrograde intramedullary nail Locked plate All implants can work if utilized properly

Retrograde Intramedullary Nail Advantages Smaller incision “Percutaneous” joint fixation Limited exposure Decreased blood loss (?) Load-sharing device, longer lever arm (if long nail utilized) Soft tissues intact Disadvantages Arthrotomy required “Percutaneous” joint fixation Lack of alignment control (“windshield wipering” of implant” Insertion thru cartilage Difficulty of insertion with total knee arthroplasty component in place

Retrograde Intramedullary Nail Don’t forget to reduce the fracture first! Nail will not assist with this as you are not achieving an isthmic fit as can be achieved with diaphyseal femoral shaft fractures Nail will happily “lock” a fracture in a malreduced position as easily as it will “lock” a fracture reduced

Plate-and-Screw Constructs Advantages Direct visualization of joint with fixation Restoration of mechanical axis Improved fixation over nail (?) Disadvantages Blood loss (?) Soft tissue stripping (?) Screw purchase in osteopenic bone Load-bearing device

Which Implant? Condylar buttress plate Fixed-angle device Blade plate Dynamic Condylar Screw (“DCS”) Retrograde medullary nail Locked plate All implants can work if utilized properly

Plan Ahead Principles of surgical treatment: 1. Careful handling of soft tissues 2. Indirect reduction techniques 3. Anatomic reduction of the articular surface and restoration of limb axial alignment, rotation, and length 4. Stable internal fixation 5. Early rehabilitation

Plating Technique Limited incisions with exposure of joint and articular segment Submuscular (not subperiosteal) plate application Fixation of implant to articular block Restore alignment Fixation of implant to shaft NO SOFT TISSUE STRIPPING !!!!

Locked Plates Advantages Disadvantages COST Submuscular “percutaneous” insertion Anatomically contoured Resists varus deformation – “fixed-angle” devices Good fixation for osteopenic bone Disadvantages May be difficult to avoid screw “traffic” utilized for reduction and fixation of articular surfaces (polyaxial implants may avoid this) COST

Locked Plating Locked plates can avoid difficulty encountered with stabilization of coronal splits in distal femoral fractures that were problematic with blade plate fixation

Locked Plating CT scan reveals multiple articular splits in both the sagittal and coronal planes

Special Tip for Locking Plates The C-Arm rarely tells the truth! Can’t judge coronal/sagittal plane alignment in small field of view Get long cassette AP/Lat views after provisional fixation and shaft reduction

Summary Have a full understanding of fracture anatomy Understand the benefits and limitations of each implant Utilize reduction techniques that are soft-tissue friendly Beware of common pitfalls (sagittal plane malreductions, etc) Results Largely Based on Surgical Technique Not on the Implant Choice