Lower limb variants

Beware 2 problems, with additive or compensatory effects e.g. foot and hip!

Rotation probs ie in-toeing and out-toeing.

Metatarsus adductus is common.  Outer edge of foot is curved, and vertical line through heel misses 2nd/3rd toe space.  Rigid forms need serial casting, else 90% improve without treatment by 6-9 months of age.

Internal tibial torsion can be seen by keeping patellae parallel (sitting, or kneeling), and seeing angle of foot.  No treatment required unless severe (tibial rotational osteotomy).

Femoral ante version is more common in girls and often familial.  W posture sitting, patella points in, eggbeater pattern running.  80% resolve spontaneously, else osteotomy (but high rate of complications).

Out toeing normal in first 24 months.  Usually external tibial torsion; occ femoral retroversion.  External tibial torsion associated with patellofemoral instability.  Beware Perthes and SUFE in school age children, esp  unilateral.

Pes Planus – Flexible or rigid?  Arch reforms on tiptoeing?  Rigid suggests congenital vertical talus (rocker bottom heel) or JIA, either way, usually painful.  Beware CP or muscular dystrophy or connective tissue disorder.  Asymptomatic is considered benign.  Insoles may be useful for pain and shoe deformation, do not correct flat foot!

Angular problems ie genu varum/valgum

(Bow/knock)  Gap between knees (intercondylar distance) should be <6cm, gap between ankles (intermalleolar) should be <8cm.  Beware rickets, renal osteodysplasia, tumours, skeletal dysplasias.  Note association between high impact sport and genu varum – cause or selection?  Increased risk of injury/OA in later life…  Differential includes Blounts disease (also associated with obesity).

Knock knees exacerbated by external tibial torsion, ligamentous laxity, obesity.  Less typical pattern of rickets but seen.

[Yeo, BMJ 2015;351:h3394 – videos too]