CP Knee Foot Ankle

 

CP kneeCP kneeEquinovarus

 

Knee

 

Hamstring contractures

 

Crouch gaitSilverskiold

 

Crouched gait in spastic diplegia

- hips and knees flexed throughout gait

- tight hamstring prevents knee extension with hip flexion

 

Options 

 

Dynamic contractures

- distal hamstring lengthening (open versus percutaneous)

 

Fixed knee contractures

- guided growth / distal anterior femoral hemi-epiphysiodesis

- distal femoral extension osteotomy

 

Distal hamstring lengthening

 

CP knee

 

Complications

- genu recurvatum / knee extension post hamstring release

- weakness hip extension / anterior pelvic tilt

- avoid by releasing medial hamstrings only

 

Technique

- semitendinosis release +/- transfer to maintain hip extension

- semimembranosus release

- leave biceps femoris intact 

- postoperative casting

 

Sung et al J Neuroend Rehab 2017

- hamstring lengthening in 314 CP patients with CP and flexed knee

- semimembranosus lengthening

- semitendinosis release and transfer

- improvement in knee flexion and gait at 2 years

 

Guided growth / Anterior distal femoral hemi-epiphysiodesis

 

CP kneeCP knee

 

Indication

- fixed knee contracture

- skeletally immature

 

Tipping et al Gait Posture 2025

- systematic review of guided growth for knee flexion contracture

- improvement in knee flexion contracture 12o

- improvement in popliteal angle 16o

 

Distal femoral extension osteotomy + patella tendon advancement

 

Indication

- knee FFD > 20o

- skeletally mature

 

POSNA distal femoral extension osteotomy CP technique video

 

Stout et al JBJS Am 2008

- 73 patients with CP treated with distal femoral extension osteotomy

- better outcomes when combined with patella tendon advancement

 

Quadriceps contractures

 

Issue

 

Tight rectus femoris

- stiff knee gait

- may be unmasked with hamstring lengthening

- limits knee flexion in gait / energy inefficient

 

Ely's test

- patient prone

- flex knee, will feel hip flex with tight rectus 

 

Options

 

Rectus femoris release

Rectus femoris transfer to semitendinosus

 

Josse et al Orthop Traumatol Surg Res 2023

- systematic review of rectus femoris release versus transfer 

- small to moderate improvement in knee kinematics with RF transfer

 

POSNA rectus femoris to semitendinosus transfer technique video

 

Excessive external rotation tibia

 

Supramalleolar tibial derotation osteotomy

 

Foot and ankle

 

Issues

 

Equinus Equinovarus Planovalgus
Equinus Equinovarus Equinovarus

 

Equinus

 

Equinus

 

Definition

 

Most common foot and ankle defomrity

- fixed dorsiflexion of ankle / unable to reach plantigrade 

- tight tendoachilles

 

Options

 

Tendoachilles lengthening +/- tibialis anterior shortening

 

Tendoachilles lengthening

 

Avoid overlengthening of tendoachilles which results in weakness / foot drop / slumping position

 

POSNA academy achilles tendon lengthening video

 

Hoke percutaneous slide technique

- mild contractures

- proximal and distal cuts medial, middle cut lateral

- cut half the tendon

 

Z lengthening of tendon

- severe contractures 

 

Joo et al J Child Orthop 2011

- 186 tendoachilles release in CP

- overall recurrence 44%

- highest in hemiplegia and younger patients

 

Equinovarus

 

Equinovarus

 

Cause

 

Contracture of tendoachilles and tibialis posterior

Most common in hemiplegia

 

Management

 

Flexible deformity

- tendoachilles release

- split tibialis posterior tendon transfer (SPLOTT)

- split tibialis anterior tendon transfer (SPLATT)

 

Fixed deformity - subtalar arthrodesis

 

Bouchard et al JBJS Rev 2025

- systematic review of split tibialis posterior transfer for equinovarus in CP

- recurrence hemiplegia 7%

- higher recurrence rate with increased age

- increased recurrence in quadriplegia 48%

 

Planovalgus 

 

Equinovarus

 

Options

 

Lateral calcaneal lengthening

Subtalar arthroesis

Subtalar arthrodesis

 

Lin et al Front Pediatr 2024

- systematic review of lateral calcaneal lengthening v arthoresis in CP planovalgus

- improved radiographic correction with calcaneal osteotomy

- increased complications with calcaneal osteotomy (recurrence / pain / ovecorrection / undercorrection)

 

CP hindfoot