Knee Dislocations: Whats My role? Do I put on the Ex Fix? William - PowerPoint PPT Presentation

Knee Dislocations: What’s My role? Do I put on the Ex Fix? William T Obremskey MD MPH Vanderbilt University Orthopedic Trauma

Disclosures • Board SEFC • OTA EBQVS Chair • No Industry Conflicts

What’s My role? • Role – Reduce Joint – Assess Neuro/Vacular – Assist Vascular if needed – Release Compartments if needed – Stabilize - ?

Do I put on the Ex Fix? • It depends

OBJECTIVES • What knee injuries are likely to result in vascular injury? • What is appropriate evaluation? • When Ex Fix? • Irreducible KD?

JAAOS December 2015

Schenck Classification KD I Multiligamentous injury with involvement of ACL or PCL KD II Injury to ACL and PCL only (2 ligaments) KD III Injury to ACL, PCL, and PMC or PLC (3 ligaments) KD IV Injury to ACL, PCL, PMC, and PLC (4 ligaments) KD V Multiligamentous injury with periarticular fracture

What Injuries? What knee injuries are likely to result in vascular compromise? • Fractures - distal femur and proximal tibia • Dislocations

INJURY KNEE DISLOCATIONS 10% - 60% rate of associated vascular injury (5% - 15% requiring surgery)

High vs Low energy KNEE DISLOCATION DeCoster JOT 1997 22 knee dislocations vs 28 “reduced” bicruciate ligament injuries • 14% popliteal artery disruptions in each • Equal risk of vascular injury

VASCULAR INJURY TIMING Miller Arch Surg 1949 Extremity salvage repair 90% at 6 hours 50% at 12-18 hours 20% at > 24 hours

DIAGNOSIS NONINVASIVE VASCULAR EXAM Lynch, Johansen Ann Surg 1991 ABI < 0.9 95% sensitivity 97% specificity

When to Ex Fix?

When to Ex Fix? • Vascular injury – To manage CPS release

When to Ex Fix? • Obese – unable to hold reduced

When to Ex Fix? • Severe Soft Tissue injury

Nerve Injury Peroneal most common 14% - 35% One third will recover One half will remain as complete palsy

Peroneal Nerve Contusion

Nerve Avulsion

Indications for immediate operative treatment Open dislocation Irreducible dislocation Popliteal artery disruption Compartment syndrome

Open Dislocation

Open Dislocation Ex Fix or Splint

Posterolateral - irreducible

Irreducible Pucker Sign

Evaluation: Radiographic Exam AP/lat/oblique MRI helpful in defining torn structures Adds to both sensitivity and specificity (can still miss LCL and PLC) Aids preop planning by defining the location of tears

Take Home Knee dislocation is challenging Not always obvious When obvious, not always reducible closed On table or formal Angiogram only for hard signs/ ABI < 0.9X Initial stabilization, then MRI prior to repair or reconstruction

THANK YOU