summary Equinovarus Foot is an acquired foot deformity commonly seen in pediatric patients with cerebral palsy, spina bifida, and Duchenne Muscular Dystrophy that present with a equinovarus foot deformity. Diagnosis is made clinically with presence of an inverted heel with a supinated forefoot, often associated with pain and callous formation along the lateral border of the foot. Treatment ranges from bracing to tendon transfers to osteotomies depending on the underlying etiology, severity of deformity, and rigidity of contracture. Epidemiology Incidence common foot deformity seen with cerebral palsy (usually spastic hemiplegia) Duchenne muscular dystrophy residual clubfoot deformity spina bifida tibial deficiency (hemimelia) though this condition is very rare Etiology Pathophysiology pathomechanics imabalance of invertors and evertors (invertors overpower the evertors) relative overpull of tibialis posterior and/or tibialis anterior gastoc-soleus complex example: in cerebral palsy the causative muscles for the varus are the anterior tibialis (AT) in 1/3 of patients posterior tibialis (PT) in 1/3 and both the AT and PT in the remaining 1/3 foot deformity muscle imbalance overview Presentation Symptoms pain painful weight bearing over the lateral border of the foot instability during stance phase results in shortened single limb stance poor shoe and/or brace fitting and shoe wear problems Physical Exam inspection inverted heel (tibialis posterior typically implicated) supinated forefoot (tibialis anterior) callous and pain along lateral border intoeing gait (foot progression angle is more internal than knee progression angle) provocative tests active dorsiflexion of foot if foot supinates with dorsiflexion, the anterior tibialis is implicated confusion test indications used in those with poor selective motor control, as in CP, and cannot dorsiflex foot when asked) method patient performs active hip flexion (with or without resistance) while seated results in ankle dorsiflexion due to mass action pattern of leg if the foot supinates with dorsiflexion, the tibialis anterior is likely a contributing to the varus deformity Coleman block test indications to test rigidity of the varus deformity do not do this in children with limited balance such as CP method patient stands on a block with the first ray off the block if the varus corrects, the deformity is flexible manual manipulation of the hindfoot can be used to asses rigidity of the varus deformity passive eversion of the hindfoot past neutral demonstrates that the varus deformity is flexible Imaging Radiographs recommended views AP + lateral of foot findings forefoot adduction is seen on the AP radiograph the talus and calcaneus are more parallel than in typical feet one can often "look down" the sinus tarsi through a visual hole there the calcaneus looks foreshortened on the lateral view the metatarsals are often "stacked" on the lateral view (instead of being in line with one another) stress fractures along the fourth and/or fifth metatarsal bases can develop secondary to repetitive load along the lateral border of the foot. Studies Dynamic EMG may be useful in distinguishing whether tibialis anterior and/or tibialis posterior is/are causing the varus in CP Treatment Nonoperative ankle foot orthosis (AFO) helps provide stability for the foot and a more stable base of support during gait should have a "wrap around" hindfoot component of the brace to help control the varus and minimize pressure points serial casting indication rigid deformity botulinum toxin injection into tibialis posterior and/or gastrocnemius indication flexible or dynamic deformities desire to delay surgery Operative gastrocnemius recession or tendoachilles lengtheing (TAL) for equinus indications fixed equinus unresponsive to non-operative measures gastrocnemius recession should be performed if the anke can be brought to neutral or above neutral with the knee flexed and hindfoot inverted, but not when the knee is extended TAL should be performed if the ankle can not be dorsiflexed to neutral with the knee flexed or extended split-posterior tibialis tendon transfer [SPOTT] or posterior tibial tendon lengthening (PTTL) indications soft tissue balancing is required if varus is flexible or rigid varus foot recalcitrant to non-operative measures and posterior tibialis contributing to varus (dynamic EMG, when available is helpful) tibialis posterior spastic in both stance and swing phase (continous activity) common patient: spastic hemiplegia in ages 5 to 7 years old technique SPOTT reroute half of tendon laterally and insert into peroneus brevis PTTL fractional lengthening of the tendon in the distal third of the lower leg either PTTL or SPOTT may be combined with SPLATT outcomes results for both surgeries are good, without clear indications for transfer versus lengthening split-anterior tibialis tendon transfer [SPLATT] indications overactive anterior tibialis on EMG when anterior tibialis contributes to varus foot, whether flexible or rigid varus deformity technique split anterior tibialis transfer to cuboid, peroneus tertius, or peroneus brevis may be combined with SPOTT or PTTL calcaneal osteotomy indications required for a rigid hindfoot varus deformity technique lateral closing wedge osteotomy (Dwyer) to incur valgus to the heel, OR lateral calcaneal sliding osteotomy to correct the varus typically combined with soft tissue balancing (as above) Complication Overcorrection (resultant valgus deformity) increased risk in children who undergo surgery at younger age children with diplegia (as oppose to hemiplegia) Wound complications most common with calcaneal osteotomy lateral incision risk decreased by using absorbable suture Hardware Pressure sores/ulcers from buttons on bottom of foot (from SPLATT to cuboid) has led some surgeons to always transfer SPLATT to peroneus tertius or brevis