The Lower Extremities: Abnormalities of Alignment in Children

Educational Objectives

The goal of this program is to improve the assessment of abnormal lower extremity alignment in children. After hearing and assimilating this program, the clinician will be better able to:

1. Distinguish intoeing from other foot abnormalities that may require intervention.
2. Identify causes of genu varum and genu valgum that may require intensive treatment or surgery.

Summary

Intoeing: previously treated with braces and interventions (now understood to be ineffective); recognize generational and geographic perspectives in parents and grandparents

Femoral anteversion (FA): hips turn in; “w-sitting” result, not cause, of FA; no need to restrict sitting position (but sitting cross-legged engages core); to observe poor external and significant internal rotation, examine child in prone position; normal rotation of femur 40° at birth and 10° by teenage years; treatment — almost always resolves with age (reassure parents); no evidence for subsequent arthritis; no special shoes or therapy required; yoga, ballet, and martial arts promote external hip rotation (but will not correct FA); surgery rarely required in healthy child; those with cerebral palsy or other neurologic abnormalities may lack coordination to compensate; surgery occasionally used to change alignment

Internal tibial torsion: more common in youngest children (<4 yr of age); child in prone position will have foot in “internal” position compared with thigh; with normal alignment, lateral malleolus posterior to medial malleolus (anterior with tibial torsion); treatment — explanation and reassurance; adult alignment and rotation achieved ≈7 to 8 yr of age; children run well (good athletes); no special shoes, therapy, or braces needed; surgery rarely indicated (sometimes performed in children with neurologic abnormalities; varies by geographic area and philosophy of orthopedist)

Metatarsus adductus (MA): curvature of foot; associated with developmental dysplasia of hip and torticollis; casting and surgery no longer used; atavistic (“searching”) great toe has abnormal appearance (used for balance; not concerning); treatment — observation; straight last shoes or switching shoes to opposite feet not indicated; no evidence that MA leads to bunions, foot pain, or issues with footwear

Differential diagnosis of foot abnormalities: club foot — combination of MA with foot “coming up and around”; treated with long-leg cast and Denis Browne bar (surgery used until mid- to late 1990s); patient may undergo outpatient surgical lengthening of Achilles tendon; calcaneovalgus foot — top of foot touches shin; resolves quickly without intervention; flexible flatfoot — common; standing on toes reconstitutes arch; inserts ineffective at creating arch; use over-the-counter arch supports for pain relief (insurance often does not cover custom supports, and children dislike them); rocker-bottom foot — congenital vertical talus; foot not flexible; painful; treated with serial casting or surgery; tarsal coalition — typically seen in older children; may present as multiple ankle sprains; foot flat and stiff; child cannot stand on toes; x-ray shows abnormal calcaneonavicular and calcaneotalar connections (sometimes surgically removed); use of fracture boot or cast often relieves pain (this treatment usually sufficient)

Coronal plane abnormalities: knees either outside ankles (bowlegs [genu varum]) or inside ankles (knock knees [genu valgum]); normal development — mild varus normal when child starts walking; by 4 yr of age, most children have some degree of valgus; adult alignment develops at 7 to 9 yr of age; earlier walkers may have greater degree of varus; most individuals have mild valgus (degree greater in women)

Differential diagnosis of genu varum: includes Paget disease, skeletal dysplasia, trauma, tumor, and infection; physiologic — resolves without intervention; round appearance, with bowing through femur and tibia; Blount disease — diagnosed using angles measured on x-ray; obtain anteroposterior hip-to-ankle views (x-ray of knee insufficient for identifying etiology of bowleg), with both legs on same film; bracing sometimes used before 4 yr of age; braces enclose entire leg and worn as much as possible (compliance difficult); surgery used for persistent disease in children >4 yr of age; “guided growth” technique involves placement of metal plates around physes (growth plates); early arthritis in medial compartment of knee common among untreated patients; rickets — causes both varus and valgus deformities; x-ray shows widened physis; legs curved to greater degree than physiologic bowing; rachitic rosary noted; tibial bowing present in >1 plane (visible from front and side); surgical correction contraindicated before medical control achieved

Genu valgum: normal intramalleolar distance <10 cm by 4 yr; unilateral valgum concerning (eg, endocrine disorder, trauma, tumor, infection); surgery rarely needed (plates guide growth of physes, to be removed once legs straighten); more invasive surgery sometimes used in, eg, child with valgus that prevents running and leads to obesity

Readings

Cozen L: Knock-knee deformity in children. Congenital and acquired. Clin Orthop Relat Res 1990 Sep;(258):191-203; Do TT: Clinical and radiographic evaluation of bowlegs. Curr Opin Pediatr 2001 Feb;13(1):42-6; Gonzales AS et al: Intoeing (pigeon toes, femoral anteversion, tibial torsion, metatarsus adductus). StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2018 Apr 25; Harris E: The intoeing child: etiology, prognosis, and current treatment options. Clin Podiatr Med Surg 2013 Oct;30(4):531-65; Rerucha CM et al: Lower extremity abnormalities in children. Am Fam Physician 2017 Aug 15;96(4):226-33; Sullivan RJ: The pediatric foot and ankle. Foot Ankle Clin 2010 Jun;15(2): ix. doi: 10.1016/j.fcl.2010.04.005.

Disclosures

For this program, members of the faculty and planning committee reported nothing to disclose.

Acknowledgements

Dr. Weiss was recorded at Pediatrics in the Islands: Clinical Pearls, presented by the Children’s Hospital Los Angeles Medical Group and held July 1-5, 2018, on Maui, HI. For information about upcoming CME conferences from the Children’s Hospital Los Angeles Medical Group, please visit www.chla.org/childrens-hospital-los-angeles-medical-group. The Audio Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

PD644002

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.