Subtle Ligament Injuries

of the Midfoot and Ankle

Robert B. Anderson, MD

Founder, Foot & Ankle Service

OrthoCarolina

Consultant, Carolina Panthers

Charlotte, North Carolina

Disclosures

Consulting/Royalties:

DJO, Arthrex, Wright Medical, Zimmer Biomet

Consulting/Research:

Amniox

You may not have seen it but it has

seen you…

Dr. Bill Hamilton

The eye sees what the

mind knows…

Sport Ligament Injuries

• Ligament injuries may be subtly unstable

• Frank diastasis not always present

Why important?

Unstable joint segments may progress to deformity/DJD

Subtle LISFRANC Injuries

Sport Lisfranc Injuries

Not all are classic or readily apparent

• 23 y/o NFL WR with right foot injury on punt return

• Minimal clinical findings

• Normal xrays/stress

• MRI = edema

Diagnosed with Midfoot “Sprain”

• Failed to improve with casting/boot x 3 months

• Decision made to proceed with open exploration

More than a Midfoot “Sprain”

• Managed with “home run” screw– Symptoms resolved

– RTP after 5 months

Lisfranc Not Always Apparent

Sport variety may be

subtle – consider…

• Painful WB

• Unable to heel rise

• Swelling and point

tenderness

– Often medial column (n-c)

– Plantar ecchymosis

Radiographic Exam

• Beware of the

proximal variant!

– Increasing

incidence in

American football

• Hammit/Anderson

– AOFAS ‘04

– TFAS ’05/’10

Proximal Variant = Medial

Column Lisfranc

• Occurring in all field

sports

• Effect of artificial

surfaces?

– Cleat

interaction???

Proximal Variant/Medial

Column Lisfranc

• Results in an

unstable first ray →

can’t push-off

• Also leads to joint

deterioration if left

untreated

Assessing Subtle Injuries

Stress testing?

• Very difficult to get

relaxed in office

– I rarely do…

Assessing Subtle Injuries

MRI = may alert to

subtle pattern

• Example: proximal

variant with edema

in navicular

• Remember = a

static test

Sometimes you just have to explore

• Fix all unstable segments– Screws

– Bridge plates

• Can use on TMT joints; avoids cartilage damage

• Hardware breakage not of concern

Subtle SYNDESMOTIC and

DELTOID Injuries

Syndesmotic +/- Deltoid Injuries =

the High Ankle Sprain

• Persistently common

– 10% of ankle sprains?

• Consistently high incidence in the NFL

– Avg > 130/season

• Multiple factors

– Cleat/turf interaction

• Ligament injuries occur as a result of torque/rotation

High Ankle Sprain - Mechanism

• Classic = foot fixed to

surface and valgus thrust

applied to leg

– External Rotation a

constant

– Often eversion component

NFL/UVa Research

• Injury modeling of the high ankle sprain

– Superficial deltoid frequently involved

– AITFL > PITFL

NFL/UVa Research

• Variable presentation

• A number of different ligaments may be effected and to varying degree of disruption

• Frank diastasis not always present

Evaluation of the HAS – Assessing

Stability

– Start with ankle radiographs

• Standing – single limb may accentuate

areas of diastasis and instability

Stress Radiographs?

– Beumer et al (2003):

not reliable for

diagnosis of

syndesmotic instability

– I have difficulty getting

players to relax!!!!

Stress Flouroscopy?

Helpful when positive…

Role of CT and MRI?

• Help to define extent of ligament injuries, OCLs, and diastasis– MRI/CT very sensitive for

detecting ligament injuries/diastasis but not prognostic (Oek, 2003)

– MRI/CT are static studies - not predictive for instability

Why do we care about Ankle

Diastasis/Instability?

• 1mm of lateral displacement of the talus results in 42% reduction in tibiotalar contact (Ramsey and Hamilton, 1976)

• Chissel and Jones, JBJS, 1995 – threshold of 1.5mm diastasis with worsening results with increasing malreduction/diastasis

• Weening and Bondari, JOT, 2005 – “the only significant predictor of functional outcome was reduction of the syndesmosis”

Treatment of Stable Injuries

Individualized• Boot/Cast

• WBTT

• Ice/NSAIDS/compression

• PRP/cortisone injections

• Strengthening/proprioception/plyometrics

• RTP when symptoms allow

– 2-8 weeks?????

Decision Making Easy when

Diastasis or Proven Instability

Need to fix to reduce risk of DJD

Treatment of Unstable

Syndesmotic Injuries

Surgery if…

1. Any diastasis

2. Instability with stress

• Stress plain films

• Weightbearing ankle xrays

• Flouroscopic exam

Reduction/fixation to reduce

risk for DJD

What about the injury that

appears stable but player not

improving…

• Persistent discomfort and swelling with activity

• Pain/weakness with heel rise

• Difficulty with cutting maneuvers

• General performance issues

Think Subtle Syndesmotic and/or

Deltoid Instability

• Clinical/functional exam

important

– Inability to perform heel rise

or repeated hop

– Peroneal/posterior tibial

tendonitis

– Chronic inflammation

– Serial MRI changes

• Worsening of bone edema

• OCLs

Test for Subtle Syndesmotic

Instability

• Wolf BR, Amendola A: Curr

Opin Orthop 2002

– Described a test for dynamic

instability = “syndesmotic

taping”

• Player asked to perform single

limb heel rise with and without

tape wrapped around distal tib-fib

• If binding assists then consider

instability and need for surgical

fixation from Wolf et al

Subtle Syndesmotic/Deltoid

Instability

• Concern = may lead to chondral injury and eventual DJD

– How do we identify those athletes with subtle syndesmotic injuries and in need of surgical stabilization

EUA with Ankle Arthroscopy

• Best diagnostic tool

• Very helpful in cases of

negative xray, positive

MRI and protracted

recovery with vague pain

– Lue et al. = arthroscopic

evaluation superior to

fluoroscopic stress testing

• Arthroscopy 2005

Syndesmotic

Instability

Syndesmotic/Deltoid Instability

• Arthroscopic evaluation is superior to any

imaging studies in subtle injuries

– Done with EUA – different exam with patient

relaxed

Deltoid Instability = Anterior Drawer with

External Rotation

Case Example

• 23 y/o WO with

recurrent high ankle

sprains

• Normal xrays, stress

imaging, flouro exam

• MRI: chondral defects

• Scope

– Chondral changes lateral

talar dome

– Loose body

– Unstable syndesmosis

Case Example

• 26 y/o RB

– Unable to return for

last 6 games of ‘12

season due to left ankle

pain after “minor” high

ankle sprain

– Normal xrays/stress;

MRI with edema in

syndesmosis/lateral

talar OCL

OCL lateral talus

with syndesmotic

instability

Case Example

• 25 y/o RB with recurrent high

ankle sprains

• Difficulty with “cutting”

• Normal xrays, stress imaging,

flouro exam

• MRI: chronic ligament

changes medial and lateral,

progressive OCL lateral talus

Case Example

• Intraop exam

– EUA – medial

instability pattern

– Arthroscopic:

synovitis, medial

laxity confirmed

Case Example

• Intraop exam

– Arthroscopic:

syndesmotic

instability

Case Example

• Intraop exam

– Arthroscopic:

chronic bipolar

OCL lateral

“Corkscrew phenomena”

Case Example

• Intraop repair

– Chondral debridement

– Superficial deltoid

• Medial Brostrom

– Syndesmotic stabilization

• Suture-button fixation

Deltoid Fixation Options

• Superficial deltoid

reconstruction

– Advancement to anterior

medial malleolus with

suture anchor(s)

Postop Treatment

• Postop

– Individualize• Size

• Time

• Severity

– Cast, NWB x 4-6 weeks, then

WB in boot 4-6 weeks

– Progressive strengthening

– RTP at 4-6 months

Syndesmotic Fixation Options

• Addition of fibular

plate may allow for

earlier and safer

return to play

– Reduce fibular

fracture risk

Syndesmotic Injuries

Complications and poor

outcomes can and will

occur

• Understand the spectrum of

the injury and importance of

obtaining and maintaining

anatomic reduction

Syndesmotic Complications

• Pain

– Inflammation, degeneration

in the syndesmosis

• Bone scan/CT helps to

diagnose

• Consider injection under

flouro or CT

Syndesmotic Complications

• Pain

– Inflammation, degeneration

in the syndesmosis

• Bone scan/CT helps to

diagnose

• Consider injection under

flouro or CT

Syndesmotic Complications

• Pain from iatrogenic

syndesmotic

injury/degeneration

– Avoid placing devices within the “functional” syndesmotic joint

• Failed hardware an issue

• Place at least 1.5cm above

joint line to avoid “true”

syndesmotic joint

– Kukreti et al: Injury ’05

The Syndesmosis is a Joint!

• Sickle shaped synovial

lined functional joint

with cartilage on both

sides

• Pistons, rotates, widens

• It has a purpose!

• Preserve when possible

Articulating

Joint

Syndesmotic Complications

• Pain

– Ossification of the

syndesmosis

• Usually incomplete

types

Incomplete Synostosis

• Chronic

inflammation/pain

• Mechanical symptoms

with activity

• Treatment

– Injection

– Immobilization

Case Example

• Incomplete synostosis with

pain/popping sensation

– Injection attempted (fluoro

assistance)

– Debridement vs. fusion

Case Example

Treatment

• Incomplete synostosis

– Debridement

Persistent/Recurrent Diastasis

• Decision making

– Condition of tibio-talar joint

– Condition of syndesmotic

joint

– Degree/direction of diastasis

and instability

– Early vs. Late?

• 6 months is arbitrary threshold

Late Diastasis (or Syndesmotic DJD)

• Best to achieve tib-fib

fusion

– ICBG; Plate and screw

fixation

– Synostoses don’t hurt but

may limit some motion –

especially external

rotation

Late Diastasis (or Syndesmotic DJD)

• Case example

– 32 y/o female triathlete

– External rotation injury

two years prior

– Treated in a boot for 3

months

– Disabling pain in

anterolateral ankle

Late Diastasis (or Syndesmotic DJD)

• Case example

– Temporary relief with

injection to

syndesmotic joint

• Flouroscopic guidance

and confirmation

– CT optional

Late Diastasis (or Syndesmotic DJD)

• Case example

– Syndesmotic fusion

• ICBG

• Plate/screw fixation

Ligament Injuries of the F/A

Summary

• Have a high index of suspicion →

diastasis/gross instability not

always present on initial evaluation

– Clinical signs (heel rise) and lack of

recovery can be as helpful as imaging

– Beware of worsening bone edema

– EUA with incision/scope if not

improving

– Fix if unstable to reduce risk of

chondral injury and DJD

Thank You