41: MPJ Pathology - Feilmeier Flashcards Preview

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1

what is turf toe?***

- classic: hyperextension (dorsiflexion) of 1st MTPJ
- now: refers to just about any injury involving the 1st MPJ

2

"sand toe"

- hyperflexion of 1st MPJ
- might be seen in dancers, gymnasts

3

how does hyperextension of first MPJ occur?***

- axial load is delivered to foot fixed in equinus/plantarflexion
- hyperextension can tear the plantar plate
- allows increased ROM of the hallux
- proximal phalanx compresses agianst met head and can even separate the sesamoids (OCD osteochondral defect of met head)

4

causative factors of turf toe

shoes
- Soft soled shoes- “the need for speed”
- Traditional football cleats had a metal plate in the forefoot which limited dorsiflexion of the 1st MTPJ
- Newer shoes lack this and allow exaggerated dorsiflexion of 1st MTPJ

surface
- Synthetic surfaces have a higher coefficient of friction and limited shock absorption * (may not contribute as much as once thought)
- Foot becomes “fixed” to playing surface and can’t adapt to external forces and absorbs all the shock

5

grade I turf toe ***

- attenuation, swelling, minimal ecchymosis
- tx is symptomatic, carbon fiber plate

6

return to play for different turf toe classification

grade 1 - as tolerated
grade 2 - up to 2 wk, may need taping/carbon fiber plate on return
grade 2 - 10-16 wk depending on sport, likely to need taping, may need surgery

7

grade II turf toe

- partial tear, moderate swelling, restricted motion due to pain
- walking boot/crutches as needed

8

grade III turf toe

- complete disruption, significant swelling/bruising. obvious instability, cartilage damage
- tx with long term immobilization or surgery

9

conservative tx for turf toe

- Orthotic (Carbon fiber plate, Morton’s extension)
- Stiff soled shoe
- Taping (hold in plantarflexion)
- Offloading with crutches/boot
- NSAIDS- tx pain only

10

when is surgery indicated for turf toe?

- large capsular avulsion with usntable joint
- diastasis of bipartite sesamoid
- diastasis of sesamoid fracture
- retraction of sesamomids
- traumatic hallux valgus deformity
- verticaly instability (positive lachman's test)
- loose body
- chondral injury
- failed conservative

11

what is predislocation syndrome?

early stage damage to plantar plate that if not addressed can lead to ... instability, elevation (hammertoe)

12

is predislocation syndrome an acute injury?

no, usually progressive onset
but can be acute

13

ddx predislocation syndrome

- neuroma ***
- stress fx
- hammertoe
- advential bursitis
- submetarsal bursa

14

describe the normal plantar plate

- Fibrocartilaginous thickening of the MPJ capsule plantarly that is strongly attached to base of *proximal phalanx just distal* to the articular surface and loosely to metatarsal head just proximal to the flare of its head
-

15

when the plantar plate tears, where does it occur?

base of proximal phalanx

16

what happens if the plantar plate ruptures?

- Proximal phalanx moves dorsally
- Extensor tendons cannot extend PIPJ and DIPJ
- Over time, the extensors act as a deforming force on the MPJ and cause further dorsal subluxation
- Flexors are ineffective plantarflexors of the MPJ and do not help stabilize the toe against the ground
- As the proximal phalanx moves dorsally, the interossei and lumbricales, which are the major plantar stabilizers of the MPJ, also move dorsal to the axis of motion and lose their plantarflexory power

17

etiology of predislocation syndrome (biomechanics)

- Lateral weight transfer (HAV/MPAV, Short first,
Elevated or unstable first, Long or plantarflexed metatarsal *second, Equinus)
- Muscle weakness (Intrinsic weakness and loss of stabilization)
- Rheumatologic Disease
- Pes Cavus- Overload
- Traumatic (10%)

18

anatomic results of overload with predisloation syndrome

- Degeneration
- Plantar plate insufficiency
- MTPJ subluxation
- Long flexor and extensor imbalance

19

s/s subjective predislocation syndrome

- “bruised” feeling
- walking on a “pebble”/ “stone”
“wadded up sock”
- feeling as if the toe has “moved”
- feeling the toe is swollen

- May be associated with numbness secondary to inflammation of a common plantar nerve or its digital branches from joint or bursal synovitis
- Increased pain barefoot/hardwood floors

20

objective s/s of predislocation syndrome

- Pain with palpation of one or more MPJ’s
- May palpate a generalized (more commonly) or focal swelling inferior to the metatarsal head
- Swelling of the base of the proximal phalanx which may be seen dorsally
- Visible elevation/deviation (Look at foot in the chair as soon as you walk into the room)

- NOT focal shaft pain
- No dorsal metatarsal shaft swelling

21

how do you perform the vetical stress test/lachman/drawer?

- Stabilize the metatarsal head only between finger and thumb. If you can move the base of the proximal phalanx dorsally by at least 2 mm, it is a positive test
- must compare to contralateral side
- push back b/w MPJ joint, not directly on met

22

staging of predislocation syndrome ***

Stage I
- Mild plantar and dorsal edema
- Extreme tenderness with palpation
- No clinical anatomic malalignment

Stage II
- Moderate edema
- Deviation of toe both clinically and radiographically
- Toe does not purchase ground in stance

Stage III
- Moderate edema about entire circumference of MPJ
- Edema extends into toe
- More pronounced deviation with possible dorsal dislocation
- Can proceed to crossover 2nd toe

23

diagnosis of predislocation syndrome

- Primarily a CLINICAL diagnosis
- AP X-ray in early stages may show increased joint space while later films will show lack of clear space as the base of phalanx moves over the metatarsal head
- Subluxation noted on lateral/oblique
- May also show transverse plane migration of the base of the proximal phalanx
- Can perform a vertical stress test and observe dorsal migration on the lateral

24

why is pronation an etiology for predislocation syndrome?

- Leads to an unstable forefoot at toeoff and causes shearing forces under the lesser MPJ’s
- Can lead to a medial and dorsal dislocation of a digit (usually the second) due to weakness of the quadratus plantae
- Causes the FDL to function medial to the axis of the MPJ and to weaken its resistance to dorsiflexion

25

hypermobile 1st ray -->

causes excessive weightbearing pressure beneath the 2nd and/or 3rd metatarsal heads

26

hammer digit syndrome -->

causes a retrograde plantarflexory force on the metahead
Stretch/strain of the PP

27

conservative tx predisloation syndrome

Oral NSAID’s and steroids (**pain only)
Rest, ice
Taping-Figure 8
Orthotics
Metatarsal pad
Padding/Splinting (Budin splint)
Shoe modifications
Increased support
Complete off loading with cam boot
Intra-articular phosphate steroids-rupture of capsular structures
***DO NOT DO

28

surgery is indicated when ..

Surgery is indicated when flexibility and reducibility of deformity are lost

29

The stage of “turf toe” injury to the hallux which involves a partial tear to the intersesamoidal ligament is:

two

30

The stage of pre-dislocation syndrome where a lesser digit first appears to not purchase the ground is:

two