19 - Midfoot Fractures Flashcards
Objectives
- Evaluation and treatment of midfoot fractures.
- Etiologies and mechanism of injury of midfoot fractures.
Overview
- Fractures including navicular, cuneiforms, and cuboid
- Often difficult to diagnose due to bony overlap on x-rays and accessory bones
- May need to get contra-lateral films, bone scan, CT or MRI
- Treatment is generally conservative if not displaced
- ORIF often indicated if fracture is displaced or have large intra articular fragment
Navicular fractures
- Most common midfoot fractures
- 62% of all midfoot fractures
- 0.37% of all fractures
Types of navicular fractures
- Dorsal avulsion
- Tuberosity
- Body
- Stress
Navicular blood supply
- Due to large amount of articular cartilage, blood supply
comes dorsally, plantarly and from tuberosity - Blood supply decreases with age
- Good blood supply to medial and lateral 1/3 of navicular bone
- Relative avascular area is the central 1/3 of navicular bone
Dorsal avulsion of navicular
- Most common navicular fracture (47% of all navicular fractures)
Mechanism of injury of dorsal avulsion of navicular
- Plantarflexion with inversion (talonavicular ligament fails)
- Plantarflexion with eversion (dorsal tibionavicular ligament (part of deltoid) fails)
- Can be seen with ankle sprains/injury
Diagnosis of dorsal avulsion of navicular
- Best seen on lateral x-ray
- Pain, edema, and point tenderness dorsally and dorsomedially at talonavicular junction
Treatment of dorsal avulsion of navicular
- Generally conservative with 4-6 weeks WB cast in neutral position
- Surgery indicated if:
o Fragment still symptomatic after immobilization
o Fragment involves > 20% of articular cartilage
Navicular tuberosity fracture
- 24% of all navicular fracture
- Often confused with accessory navicular
- Accessory usually bilateral
- Has smoother edges with round appearance
- Accessory navicular can also be symptomatic if fibrous union disrupted
Mechanism of injury of navicular tuberosity
- Eversion
- Pull of Posterior tibial tendon or spring ligament causes avulsion
Clinical evaluation of navicular tuberosity fracture
- Pain over navicular tuberosity with WB
- Pain with eversion of foot
X-ray findings of navicular tuberosity fracture
- Seen best on lateral oblique
- Fragment usually not displaced due to soft tissue attachments
Treatment of navicular tuberosity fracture
- Usually conservative w/ WB cast 4-6 wks in neutral or slightly plantarflex and inverted position
- Surgery indicated if:
o Nonunion with continued symptoms after immobilization
o Significant displacement – usually > 5mm
o ORIF if fragment large and significant cartilage involvement
Navicular body fracture
- Incidence: 29% of all navicular fractures
- Types
o Nondisplaced (vertical or horizontal)
o Displaced
Mechanism of injury for nondisplaced navicular body fracture
- Multiple – usually fall with foot striking plantarflexed
- Foot then may abduct or rotate causing fracture
- Navicular gets trapped between cuneiforms and talus
- Forced dorsiflexion of the forefoot on a pronated rearfoot
Diagnosis for nondisplaced navicular body fracture
- Usually best seen on oblique and lateral views
Treatment for nondisplaced navicular body fracture
- Short leg walking cast 6-8 weeks
Mechanism of injury for displaced navicular body fracture
- Foot strikes plantarflexed and then buckles at midfoot
- This causes soft tissues fail and allow displacement
Types of displaced navicular body fractures
I – Transverse fracture
o Dorsal fragment
Treatment for displaced navicular body fracture
- Closed reduction difficult due to soft tissue attachments
- Usually require ORIF with NWB short leg cast 6-8 weeks
- May need ex-fix if highly comminuted or arthrodesis
Complication rate for displaced navicular body fracture
- Sangeorzan et al showed 28.5% rate of aseptic necrosis
- Postoperative arthritis common
Navicular stress fracture
- Accounts for 15% of pedal stress fractures in athletes
- Usually occurs @ central to lateral 1/3 of the body – this area relatively avascular
- Usually occurs in track and field athletes (sprints, hurdles etc.)
Navicular stress fracture clinical findings
- Clinical suspicion must be high
- Pain dorsum of foot and medial arch
- Direct pain with palpation and little edema
- Pain with single leg heal rise
- Exacerbated with activity and relieved by rest
Navicular stress fracture radiographs
- X-rays often negative especially initially
- Usually best seen on AP view
- Get bone scan or CT
Navicular stress fracture treatment
- NWB cast for 6-8 weeks
- Palpate area of stress fracture
- If pain continue, immobilization is needed
- If not may start physical therapy and increased activity
- Full activity at 3-6 months with orthotics
- If fracture becomes complete and/or goes to nonunion ORIF may be necessary with bone graft
CASE STUDY
- An 18 year old male high school baseball player experienced gradually increasing medial midfoot pain during the season. Oblique and lateral x-rays revealed no abnormalities, but an anteroposterior radiograph of his foot (a) revealed slight radiolucency at the navicular (arrow).
- A coronal CT scan (b) demonstrated a nondisplaced stress fracture running through the navicular from dorsal to plantar (arrow)
- The patient responded to 8 weeks in a non-weightbearing case and his immobilization was supplemented with noninvasive electromagnetic bone stimulation
Notes on meta-analysis (Torg et al.)
- Looked at different treatment modalities for the treatment of navicular stress fractures
- 4 treatments
o NWB cast for 6 weeks
o NWB cast for less than 6 weeks
o WB
o Surgery - Looked at average time to return to activity
- NWB led to less time to return to activity
Cuneiform fracture incidence
- 4.2% of tarsal fracture
- Often associated with other tarsal and/or metatarsal injuries
Cuneiform fracture types
- Avulsion: medial cuneiform from pull of AT tendon
- Body: MOI is direct trauma or axial/rotational forces
- Fracture/dislocation: MOI is foot striking in plantarflexion causing soft tissues to fail (often seen with Lis franc’s injury)
- Stress fracture
Treatment for cuneiform fracture
Displaced fracture or large fracture fragments
o Closed reduction with or without traction and percutaneous pinning
o ORIF
o NWB 6-8 weeks
Nondisplaced fracture
o WB cast or fracture walker for 6-8 weeks
Cuboid fracture incidence
- Rarely an isolated injury
Types of cuboid fracture
- avulsion
- simple body fracture
- compression
Cuboid avulsion fracture
o Most common
o Pull of the inferior calcaneocuboid ligament
o Often associated with ankle sprains
Cuboid simple body fracture
o Foot strikes in plantarflexed position with axial or rotary forces
o Direct trauma
Compression cuboid fracture
o “Nutcracker fracture”
o When cuboid gets caught between the bases of met bases 4 & 5 and calcaneous
o MOI – severe abduction of foot, often in plantarflexed position
o Force of injury greater
Clinical presentation of cuboid fracture
- Pain along lateral column
- Pain with passive abduction/adduction & inversion/eversion of midfoot
- Other sources of cuboid pain: subluxed cuboid, peroneus longus tendonitis, os perineum, arthritis
Radiographs of cuboid fracture
- May be difficult to see on x-rays, so get all three views
- CT or MRI if suspicion high
Treatment of cuboid fracture
- Avulsion fracture or body fracture (nondisplaced): usually WB in boot or cast for 6 weeks
- Comminuted/crush injuries: surgery usually warranted (ORIF, Ex-Fix, calcaneocuboid fusion)
- Need to get cuboid back out to length in comminuted/crush injuries
Conclusion
- Midfoot fracture often hard to diagnose on x-ray due to bony overlap
- Clinical suspicion needs to be high
- Relatively rare fracture with navicular fracture being most common
- Most can be treated conservatively unless fracture highly articular or displaced
CASE STUDY 1
Patient
o 60-year-old female with foot trauma
Radiographs
o X-ray shows malalignment
o MRI shows darks spot
Stress fracture
o CAM boot with non-weightbearing status for 6 weeks
o Navicular is the key to being non-weightbearing
o Since the navicular has low vascularity, it needs to be non-weightbearing to promote healing
CASE STUDY 2
Patient
o 17-year-old male reports to ED after vehicle backs over his midfoot
o Patient has noted pain and edema over midfoot
o Otherwise healthy
Radiographs
o X-ray shows fracture of cuboid and navicular with displacement
Initial treatment
o Patient sent home and allowed to be weightbearing
o Had continued pain
o Had new x-rays taken 5 days later
Returned after 5 days
o X-rays show displaced navicular and displaced fracture of cuboid
o CT shows the same, more detail
Treatment
o Surgery: ORIF, primary arthrodesis, external fixation (there is shortening from crush injury)
o The downfall of primary arthrodesis is that the patient will be stiff and he will continue going
o Regardless, he will likely have arthritis
o Ex-fix was determined to be the best option
Follow up
o External fixator removed
o Patient continued to have pain in foot with peroneal spasm and a locking of the STJ
o The next best treatment option was an arthrodesis
o 4 months later he was
CASE 3
Patient
o 64-year-old female presents to clinic with midfoot pain that is not getting better
o Went to ER 3 months ago when her foot and angle “gave out” but they sent her home with no follow-up recommendation
X-rays
o Fracture of medial cuneiform
o Get a CT to follow up and confirm
PE o Pain with palpation with medial midfoot and pain with midfoot range of motion o Some swelling noted around the midfoot o No erythema or ecchymosis o No pain with muscle strength testing
Where is the pathology?
o Medial cuneiform oblique fracture
Treatment
o Oblique fracture is an unstable fracture, so need ORIF since it has been there
o Could go more conservative, since there is good alignment so arthritis in the future is not a major concern
o Patient was placed in a CAM boot and allowed minimal weightbearing
o Bone stimulator was ordered
o Patient started to show decreased symptoms and signs of healing 6 weeks after initial presentation
