pes cavus

Question 1

Radiographic angles for pes cavus:

CIA

Mearys angle

Angle of hibbs

Cyma line

Answer 1

CIA: >30; Meary’s angle >6 deg, Hibbs angle <150 deg

posterior break in the cyma line

Question 2

Etiologies of pes cavus

Answer 2

neuromuscular disorder: 
Spina bifida
 Charcot Mariet tooth 
Friedreich ataxia 
poliomyelitis 
CP 
myelomeningocele

Question 3

what type of orthotic would be useful for pes cavus

Answer 3

extra depth shoes combined with metatarsal bar

Question 4

1. Metatarsus Cavus: local vs global

Answer 4

-apex at Lisfranc’s joint

a) Local - involves only plantar flexion of 1st ray
b) Global - involves entire Lisfranc Articulation
Note: Differentiating these two is important in determining proper surgical procedure

Question 5

Flexible anterior cavus compensation

Answer 5

• Retraction of toes - because EDL has longer distance to course, it will pull toes
• Reverse buckling at MPJ
• Anterior cavus is seen non-weight bearing and reduces with weight bearing, due to lesser tarsus adapting (lesser tarsal sagittal plane flexibility)

Question 6

Rigid anterior cavus compensation

Answer 6

-Functional limitation of ankle joint dorsiflexion caused by premature use of the ankle joint motion to compensate for pure sagittal plane anterior pes cavus deformity

• No STJ compensation
• CIA increases from dorsiflexion of foot at ankle. Called pseudoequinus

Question 7

Forefoot Cavus

Answer 7

(apex at Chopart’s joint)

a) Occurs at MTJ
b) Pathognomonic dorsolateral prominence of the Talar head

Question 8

Posterior Cavus

Answer 8

Primarily STJ deformity

• Deformity in rearfoot resulting in a high C.I.A.
• Meary’s angle < 10°

8. Frontal plane- varus (fixed) rearfoot - non-reducible
9. Posterior Cavus Compensation (Sagittal plane)

Question 9

Coleman block test

Answer 9

Coleman Block test used to determine if RF varus is 1° or 2° deformity

If the heel varus corrects to neutral position, the hindfoot is mobile (flexible). Thus, the deformity seen clinically is due to plantar flexion of 1st metatarsal and surgical procedures may be directed at correcting forefoot pronation due to the 1st metatarsal flexion. If the hindfoot remains in varus there is fixed hindfoot inversion deformity (or possibly spasticity of the tibialis posterior). Isolated correction of the excessive plantar flexion of 1st metatarsal alone will not be successful. Surgical correction of both the forefoot and hindfoot are required.

Question 10

Jones Tenosuspension/indication

Answer 10

Transfer EHL from the hallux to the 1st metatarsal
with IPJ fusion

Indications: A flexible Plantarflexed 1st ray, weak Tibialis Anterior, hallux malleus, pressure prob to 1st met head

Question 11

Cole osteotomy

Answer 11

Dorsiflexory closing wedge osteotomy (midtarsal) with removal of a dorsally based wedge. The wedge is removed from a distal cut through the cuboid and cuneiforms coupled with a proximal cut through the cuboid and navicular. This elevates the forefoot out of equinus.

corrects mainly in the sagittal plane, and is primarily indicated for rigid anterior pes cavus/global anterior cavus.

Question 12

Japas V Osteotmy Procedure

Answer 12

Indicated for anterior pes cavus

apex of V is at the highest point of the cavus, usually in navicular.

Lateral limb of V extends through cuboid, and medial limb extends through medial cuneiform.

osteotomy shifts dorsally

Question 13

Dorsiflexory fusion through the TN and CC

Answer 13

DuVries

Question 14

dorsiflexory wedge/fusion across the TMT J

Answer 14

JAHSS