CONGENITAL VERTICAL TALUS

Kenan Aksu, D.O., Pediatric Orthopaedic Resident

S. Jay Kumar, M.D., Orthopaedic Attending

August 22, 1995

CLINICAL CASE PRESENTATION

ORTHOPAEDIC DEPARTMENT

THE ALFRED I. DUPONT INSTITUTE

WILMINGTON, DELAWARE

ETIOLOGY/HISTORY:

• synonyms: Congenital convex pes valgus, congenital flatfoot with talonavicular dislocation, congenital rigid rocker Bottom foot
• etiology unknown
• high incidence with various congenital anomalies and neuromuscular diseases:
• myelomeningocele
• CDH
• arthrogryposis
• Trisomy 13 - 15 and Trisomy
• Marfan's syndrome
• male: female ratio equal (Crawford, 1983)
• bilateral 50% right>left

PATHOLOGIC ANATOMY:

• calcaneous is in valgus and equinus with no anterior talocalcaneal articulation
• talus is fixed in a vertical position with associated hypoplasia of the talar head and neck
• navicular articulates with the dorsal cortex of the talar neck
• tibionavicular and dorsal talonavicular ligaments are contracted precluding reduction of the navicular on the talus
• contracted calcaneocuboid ligament caused forefoot abduction
• posterior capsule and subtalar joint are contracted
• anterior tibial, extensor hallicus longus, extensor digitorum longus
• peroneal, and Achillis tendons are contracted
• posterior tibial tendon as well as the peroneal tendons are anteriorly displaced

CLINICAL FINDINGS:

• convex deformity of plantar aspect of foot
• heel is in valgus and equinus
• tight heel cord
• talar head can be felt on the medial plantar aspect of foot
• forefoot is abducted and dorsiflexed at the midtarsal joint
• foot is fixed in this position due to the contractures of the soft tissue

RADIOGRAPHIC FINDINGS:

Standing AP and lateral, lateral plantar flexion and lateral dorsiflexion views must be obtained.

AP VIEW:

• increased talocalcaneal angle
• forefoot abduction

LATERAL VIEW:

• calcaneous in equinus
• vertical position of the talus
• dorsal displacement of forefoot on talus

LATERAL PLANTAR FLEXION VIEW: ( vertical talus vs. oblique talus)

• Talar metatarsal axis (S. Jay Kumar 1977)
• a line bisecting the talus should pass through the longitudinal axis of the metatarsals
• normal: aligned in lateral and lateral plantar flexion views
• oblique talus: malaligned in lateral view and aligned in the lateral plantar flexion view
• vertical talus: malaligned in both the lateral and the lateral plantar flexion view

LATERAL DORSIFLEXION VIEW:

• assess the degree of fixed equinus of the calcaneus

CLASSIFICATION (S. Jay Kumar 1982)

• Group I: supple feet that resemble calcaneovalgus feet radiograph needed to make the diagnosis
• Group II: children with rigid feet some of which are part of a syndrome
• Group III: vertical talus associated with Trisomy 13 - 15 or 18
• Group IV: vertical talus associated with neuromuscular problems such as spina bifida

TREATMENT:

goal is to reduce and maintain the anatomic relationship of the navicular and calcaneus to the talus

CASTING:

• start at birth continue for 3 to 4 months
• stretches soft tissues for preparation of future surgery
• reduce talo navicular dislocation
• elimination of forefoot valgus
• position of foot in casting
• forefoot in equinus, varus and supination
• hindfoot in dorsiflexion and inversion

SURGICAL:

• number of surgical procedures have been described
• soft tissue procedures include posterior capsulotomy, tendon lengthenings (EHL, EDL, AT, Peroneal and Achillis tendons) and tendon transfers (split ATT and Peroneal tendon)
• bony procedures include excision of navicular, talecomy and subtalar/triple arthrodesis

REFERENCES:

1. Kumar S.J., Bowen H.R., Ramsy P.L. Foot Problems in Children. Instruction al Course Lecture, 31:235-251,1982

2. Kumar S.J., Ramsy P.L. Vertical and Oblique Talus: A Diagnostic Dilemma. Orthopaedic Transcriptions 1:108,1977

3. Tachdijian M.O. Congenital Convex Pes Valgus. Orthopaedics Clinics of North America 3:131-148,1972

4. Drennan J.C., Sharrard W.J.W. The Pathological Anatomy of Convex Pes Valgus. J. Bone Joint Surg.(Br.) 53:455-461,1971

5. Dodge et al. Treatment of the Congenital Vertical Talus: A Retrospective Review of 36 Feet with Long-Term Follow up. Foot and Ankle 7:326-332,1987

6. Jacobsen S.T., Crawford A.H. Congenital Vertical Talus. J. Pediatr. Orthop. 3:306-310,1983