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