Listen to our episode on distal femur fractures  as Dr. Spitler  gives us an excellent overview! 

Dr.Clay Spitler completed medical school at the Medical College of Georgia, residency at the University of Tennessee College of Medicine, and fellowship at Harborview Medical Center.

Goal of episode: To develop a baseline knowledge on distal femur fractures.

We cover:

• History and physical
• Pertinent imaging
• Classification 
• Treatment options (non-on v op)
• Surgical tx options (type A,B,C)

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Disclosures: 

NailedIt Ortho reports no relevant financial disclosures. Dr. Cole and Dr. Fitts report no relevant disclosures. This podcast is NOT medical advice, the podcast is for educational purposes only. Please consult your doctor prior to making any medical decisions.

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Dr. Fitts and Dr. Cole are orthopaedic surgery residents and the hosts of the NailedIt Ortho podcast. 

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Distal Femur Notes w/ Dr. Spitler

Intro

• Typical deformity is apex posterior and displacement of distal fragment

Open distal femur fx

• Traumatic wound is typically anterior
• Grade 3B and 3C typically ex fixed

Vascular injury

• Less common cuz vascular bundle is tethered prox in the adductor hiatus
• If vasc injury (cold limb)- if ischemia time over 6hrs- consider fasciotomy

Ligament injuries

• Common to delay ligament repairs

Periprosthetic distal femur fx

• If prosthesis loose- revision arthroplasty w/ long stem
• It stable> locked plate or retrograde nail

PE

• ATLS
• Swelling, limb shortening, external rotation. 
• Bruising, contusion, open fx, pulses

Imaging

• Knee/femur.
• Traction radiographs if shortening
• 40% of coronal plane fx, Hoffa- missed on normal imaging
• CT w/ recon 3D

Classifications

• OTA

Pathoanatomy

• Supracondylar area is distal 15cm of femur
• 25 degree inclination on medial surface, 15 on lateral
• On AP- implants placed anterior may appear good length but be too long
• Immediate below lateral epicondyle- popliteus tendon groove
• Femoral artery- runs anteromedially thru mid thigh in hunter canal- btwn extensor and adductor compartments, beneath sartorious 

Non op tx

• High comorbidities
• Femoral traction in the OR/ prox tibia> once callus- switch to fracture brace.
  • Can have bedrest complications
  • In 1960’s- was preferred treatment
• No more than 7-10 degrees malalignment in sagittal plane

Operative tx

–   ORIF History

o   Hx- used to be tx w/ unstable (non locking) distal femur plate (condylar buttress)

§  Inferior results- led to malunion- need for bone grafting-stiffness, etc

§  Advanced to 95 degree blade plate

§  Now- locked plating- forming a fixed angle construct

·  LISS plate

o   Original “internal fixator”- plate applied w/ unicortical locking screws- so no compress to bone

o   Mechanically superior to blade plate or DCS

Approaches

–   Lateral

–   AL- modification of lateral parapatellar arthrotomy

–   Medial approach- sub vastus- can extend to medial parapatellar arthrotomy

Operative Tx

Type A

–   ORIF w/ lateral approach, contoured plate

o   Traction/ femoral distractor

o   Towel bump

o   King kong clamp

o   Periarticular plate as reduction tool

o   Posterior cortex constant fragment

o   Plate is load sharing in simple fx patterns

o   Comminution/Osteoporotic

§  Plate is fixed to proximal and distal fx- allow metaphyseal comminution

§  Must make sure that distal screws parallel to joint surface on AP

§  Eight or more screw holes above the most proximal aspect of fx if possible (78)

§  Guide pin closest to joint- designed to restore varus/valgus alignment if parallel to joint axis

• Minimally invasive plate
• 95 degree condylar blade plate/dynamic condylar screw device fixation
  • Widely replaced by periarticular locked plates
  • Requires blade to be placed correctly in 3 planes symmetrically

–   DCS plate

o   Based on compression screw common used for hip fx

o   Disadvantage- bulky size of implant

Tx of OTA type B

–   buttress plate

–   W/ femoral shaft fx

o   Periarticular screws

–   Hoffa fx (coronal shear fx of lateral or medial condyle)

o   Tx w/ 2.7, 3.5, or 4mm lag screws A-P, countersunk below anterior articular surface

Tx of OTA type C

• C1-simple splits-
  • Tx w/ nail v orif
    • can reduce condyle w/ clamp w/ open v minimal invasive- tx 3.5,4.5,6.5 lag screws, outside of footprint of late on lateral femoral condyle or nail path
• C2/C3
  • ORIF through open arthrotomy (AL?)

Surgical pitfalls:

–   Plate too anterior- can lead to unicortical screws

–   Plate too posterior- screws into intercondylar notch

–   Plate too posterior- golf club deformity (posterior portion of lateral condyle projects more laterally than designed for plate>> leads to medialization of condylar segment)

–   Plate too distal- intra articular screw placement, golf club deformity (convex part of plate pushes condyles medial)

–   Plate too flexed/extended- unicortical screws, posterior thrust

Post op

• Early knee ROM
• CPM w/ ICU patients?
• Type A- PWB?
• Type B/C- NWB for 10 wks

Outcomes after orif

• High rates of delayed union, nonunion, infection’

Retrograde nailing

• Relative indications 
• Most put nail past isthmus of femur to lesser troch
• Approaches- medial patellar or split, or depending on comminution, full medial or lateral parapatellar arthrotomy
• Technique 
  • Manual reduction, use of femoral distractor w/ eccentric or unicortical pins. Towel under distal fragment. Schantz pin attached to T handle chuck
  • Enter- anterior to PCL. (Just anterior to blumensaats)

Complications

• Malalignment/malunion- 
• Nonunion- revision +/- grafting
• Infection
• Knee stiffness
• Post traumatic arthritis

Source

Rockwood and Greene- Trauma- Distal Femur Fractures Chapter 

Collinge, C. A., Gardner, M. J., & Crist, B. D. (2011). Pitfalls in the application of distal femur plates for fractures. Journal of orthopaedic trauma, 25(11), 695-706.