summary Metatarsus Adductus is a common congenital condition in infants that is thought to be caused by intra-uterine positioning that lead to abnormal adduction of the forefoot at the tarsometatarsal joint. Diagnosis is made clinically with medial deviation of the forefoot with normal alignment of the hindfoot. Treatment is generally nonoperative with stretching if the deformity can be passively corrected, and with casting if the deformity is rigid. Surgical management is indicated for patients with progressive deformities who fail nonoperative management. Epidemiology Incidence occurs in approximately 1 in 1,000 births equal frequency in males and females bilateral approximately 50% of cases Increased incidence in late pregnancy first pregnancies twin pregnancies oligohydramnios Associated conditions DDH (15-20%) torticollis Etiology Mechanism thought to be related to packaging disorder caused by intra-uterine positioning Presentation Symptoms parents complain of intoeing, usually in first year of life Physical exam tickling to foot can allow evaluation of active correction evaluation for intoeing metatarsus adductus forefoot is adducted lateral foot border is convex instead of straight a medial soft-tissue crease indicates a more rigid deformity normal hindfoot and subtalar motion femoral anteversion hip motion shows >70° internal rotation (normal is 30-60°) and decreased external rotation patella internally rotated tibial torsion observe foot-thigh angle in prone position > 10° of internal rotation is indicative of tibial torsion (normal is 0-20° of external rotation) Classification Bleck classification by heel bisector method (Beck, JPO 1983) Bleck classification heel bisector method Normal Heel bisector line through 2nd and 3rd toe webspace Mild Heel bisector line through 3rd toe Moderate Heel bisector through 3rd and 4th toe webspace Severe Heel bisector through 4th and 5th toe webspace Berg classification Berg Classification Simple MTA MTA Complex MTA MTA, lateral shift of midfoot Skew foot MTA, valgus hindfoot Complex skew foot (serpentine foot) MTA, lateral shift, valgus hindfoot Imaging Radiographs only indicated in older children Differential Causes of Intoeing Condition Key findings Metatarsus Adductus Medial deviation of the forefoot with normal alignment of the hindfoot Internal Tibial Torsion Thigh-foot angle > 10 degrees internal Femoral Anteversion Internal rotation >70 degrees and < 20 degrees of external rotation (tested in prone position) In-toeing associated with the following necessitates further work-up pain limb length discrepancy progressive deformity family history positive for rickets/skeletal dysplasias/mucopolysaccharidoses limb rotational profiles 2 standard deviations outside of normal Foot deformities clubfoot atavistic great toe (congenital hallux varus) skewfoot serpentine Foot (complex skew foot) a condition that can be considered on the axis of severity of metatarsus adductus residual tarsometatarsal adductus, talonavicular lateral subluxation, and hindfoot valgus different from metatarsus adductus in that nonoperative treatment and casting are ineffective at correcting deformity Treatment Nonoperative a benign condition that resolves spontaneously in 90% of cases by age 4 another 5% resolve in the early walking years (age 1-4 years) Nonoperative treatment modalities Condition Nonoperative Treatment Flexible deformities that can actively be corrected to midline No treatment required Flexible deformities that can passively be corrected to midline Serial stretching by parents at home Rigid deformity with medial crease Serial casting with the goal of obtaining a straight lateral border of foot Operative metatarsus adductus tarsometatarsal capsulotomies indications aged 2-4yr with failed nonop management lateral column shortening and medial column opening osteotomies, multiple metatarsal osteotomies indications age > 5yrs (as the deformity may correct with growth until this age) resistant cases that fail nonoperative treatment (usually with medial skin crease) severe deformity produces difficulty with shoeware and pain technique lateral column shortening done with cuboid closing wedge osteotomy medial column lengthening includes a cuneiform opening wedge osteotomy with medial capsular release and abductor hallucis longus recession (for atavistic first toe) serpentine foot opening wedge and closing wedge osteotomies indications indicated if serpentine deformity is symptomatic and significantly limits function operative treatment is difficult and often times deformity is accepted and observed technique calcaneal osteotomy for hindfoot valgus possible midfoot osteotomies to correct midfoot and forefoot deformities multiple metatarsal osteotomies with forefoot pinning and tarsometatarsal capsular release (Hamen procedure) Prognosis Long-term studies show that residual metatarsus adductus is not related to pain or decreased foot function Associated with late medial cuneiform obliquity (not hallux valgus)