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High Energy trauma & the knee
Lorenzo Calabro MBBS Hons Qld, M. Eng, B. Phty, FRACS (Ortho)
QOPN conference 8 Sep 2017
Affiliations/Conflicts of interest
Overview
Modern Orthopaedic approach to high energy
trauma
(It’s not about the bone)
Multi-ligament knee reconstruction
What predicts poor outcomes in lower limb trauma?
• delayed union
• Infection
• Contracture
• weakness
What predicts poor outcomes in lower limb trauma?
• delayed union
• Infection
• Contracture
• weakness
ENERGY OF INJURY
What predicts poor outcomes in lower limb trauma?
• delayed union
• Infection
• Contracture
• weakness
ENERGY OF INJURY
SOFT TISSUE INJURY
Energy?
• Low High
Images
Energy? The Ballistic example
• Low High
• <350m/sec (pistol) • Backslab and keflex
• >500m/sec (assault rifle) • Life changing injuries
What is soft tissue “stripping?”
• Muscle origins/insertions have large surface area
• Static x-rays don’t reflect the position of maximum displacement
• Tibia example (+ pic)
• Shoulder skin reduction pic / ankle pic
Case example
• Mr EK
• 47M computer programmer
• Motorcycle drove into rear of ute which stopped suddenly
• Impact borne by left leg with large wound anteromedial knee
• History of old ski injury to left tib/fib (healed)
• No LOC. Arrived by ambulance
• Primary and secondary survey:
– Injuries limited to left lower limb
• Wound images
Management principles simplified
• Debridement
• Antibiotics
• Stabilise
• Soft tissue coverage
• Debridement – With a knife/with saline/with dressing changes…etc.
• Antibiotics – Guided by contamination / mechanism… Always cover Staph
• Stabilise – Temporary vs Definitive. Brace/slab/external fixation/internal fixation
• Soft tissue coverage – Dial a friend
Mr EK continued….
• Debridement…. 1st
• + Antibiotic prophylaxis (& tetanus!)
Reduce and stabilise….
• Debridement…. 2nd (dial a friend)
• Debridement…. 3rd (get your friend to do it)
What about the knee?
• Multi-ligament knee injury (MLKI)
– 60x less frequent than isolated ACL
– Uncommon but perhaps underdiagnosed
– Interesting anatomy kinematics and associations
– Can be catastrophic if missed
– High impact on QOL
MLKI
What?
• Anatomy
– Big 4 ligaments + PLC
• Association with knee dislocation
– Final position does not reflect maximal displacement!
• Association with neurovascular injury
– 10-40%
– Catastrophic if missed
– Poor outcome despite Rx
– Behoves thorough and ongoing examination
• The Big 4 do not stabilise in isolation
• capsulo-ligamentous injury is not quantified but shouldn’t be ignored
• Eg PCL alone vs PCL and helpers.
• Clinical examination (under anaesthetic) is key
• Obese
• Majority female ?lig laxity
• Low energy
• High incidence nerve/vessel injury (~40%)
• 2 amputations in 17 patients
• BMI associated with neurovascular injury
• Poor outcome
MLKI Who?
• Mean age 32-35
• Male:Female 1.1 - 2.5:1
• 60x less common than just ACL recon
• Only 1.4% of surgeons do >2/yr
Mechanism
• #1 MVA
• #2 high energy Sports injury
• #3 Ultra low energy in obese / lig. lax
• 17% open (Arom et al)
Direction (which way the tibia goes)
• Anterior 30%
• Posterior 22%
• Medial 4%
• Lateral 15%
• Rotatory 4.5%
• Spontaneous reduction 24.5% – Green et al 1977 JBJS in Arom
– (images)
Case example demographic + anatomy
• a little old but otherwise typical
Who does poorly?
• Open dislocation infection rate 43% and amputation rate 17%
• Vascular injury 40% in A/P vs 3-20% in M/L
• 20-35% across literature
• Probably lower in group #2 and higher in groups #1 and #3
ASsessment
• Life before limb
• Is the popliteal artery and the CPN working?
– May need ongoing monitoring
• Is it or has it been dislocated?
≥2 major (complete) lig injuries = probable
• Which direction is the instability clinically?
• MRI confirmation
Mr EK assessment
• MRI
• EUA
Acute Rx
• Reduce
• Stabilise external fixation vs splint
• Assess popliteal artery
• Manage more urgent injuries
• Get an MRI and think about it
What to go away and think about
• If?
• When?
• How?
Can we leave it alone?
• surgical stabilisation generally indicated
• …. But there will be exceptions
When to intervene
• Recon vs repair (avulsions etc.)
– Bony avulsions heal
– Midsubstance ligament injuries don’t
– There’s a time limit to facilitate good repair
• Is an arthroscopy possible
– Consider skin/capsular integrity
• Do you have a choice?
– Vascular/soft tissue interventions take precedence
Staged vs single surg
• Aim to do everything between 2-3 weeks post injury if you can.
• One repair protects the other
• ACL can wait if it has to
Graft options
Graft options
• Long and strong and biologically optimal • Hamstring (both sides) • Quads tendon Autograft • BPTB
• Allograft • Synthetic
How
• Anatomical graft origin / insertions
• Minimise soft tissue damage on approach
– To common peroneal nerve
– To popliteal artery
– To intact ligaments / muscles
Case example
• Available grafts
• Pass grafts as anatomically as possible
• Tension in correct order and position
Rehab (summary)
• Not evidence based
• Weight bearing/bracing/ROM individualised
• Long recovery “2 years”
• Focus on proprioception with acceptance that it will probably never be normal
Rehab (details)
Outcomes
• Best in acute recon with minimal acute chondral damage
• Return to sport optimistic
• Return to work and ADLs likely
• Note objective scores in tables above from Dwyer et al.
Bibliography
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