Chapter 4.9a Congenital Malformations and Deformations of the Musculoskeletal System: Talipes Equinovarus (Q66.0)

Talipes equinovarus (TEV) is a specific and common type of what is sometimes called “clubfoot”, a term that encompasses a range of anomalies of the ankle or foot present at birth (see Fig. 4.33). TEV can be defined as fixation of the foot (forefoot and hindfoot) in plantar flexion (equinus), deviation toward the midline (varus) and upward rotation so the foot rests on its outer side (supinatus). In other words, the foot points downward and inward and is rotated outward axially as shown in Fig. 4.34.

Fig. 4.33. Talipes equinovarus

Fig. 4.33. Talipes equinovarus

Photograph and x-ray source: Dr Idalina Montes and Dr Rafael Longo (Puerto Rico).

Fig. 4.34. Foot positions

Fig. 4.34. Foot positions

TEV has a wide spectrum of severity. In milder cases it is “positional”, meaning that it can be gently manipulated into a normal position and typically does not require orthopaedic or surgical interventions, and is excluded from birth defects surveillance. In more severe cases it can be “rigid” or “fixed”, in that it cannot be manipulated into a normal position and requires orthopaedic or surgical treatment, and is considered a major birth defect.

The most common congenital deformity of feet is TEV; however, there are other forms of clubfoot, specifically talipes calcaneovalgus (in which the ankle joint is dorsiflexed and the forefoot deviated outwards), and talipes calcaneovarus (in which the ankle joint is dorsiflexed and the forefoot deviated inwards).

Relevant ICD-10 codes

Q66.0 Talipes equinovarus
Q66.8 Other congenital deformities of feet, clubfoot NOS (not otherwise specified)
Q66.1 Talipes calcaneovarus
Q66.4 Talipes calcaneovalgus
Q66 Congenital deformities of feet: Avoid using this general code if more specific information is available.
Q66.8 Other congenital deformities of fee; Clubfoot NOS (not otherwise specified): Minimize the use of this code if possible; describe the anomaly so a more specific code (e.g. Q66.0) can be used.


Prenatal. Clubfoot can be identified or suspected on prenatal ultrasound. However, it should not be included in birth defects surveillance data without postnatal confirmation. The primary utility of prenatal diagnosis of clubfoot is in its indication for additional evaluations for the genetic conditions and structural anomalies that are commonly associated with TEV.

Postnatal. Clubfoot is readily diagnosed in the newborn examination. Cases should be followed and evaluated sequentially to assess the degree of severity and whether treatment other than manipulation is necessary. Sometimes other birth defects of the foot or leg might mimic clubfoot. For example, a deficiency of the tibial bone in the leg might look like a talipes. Imaging studies (typically, radiographs) might provide supplemental information to aid in diagnosis.

Clinical and epidemiologic notes

TEV is bilateral in about 60% of cases, and when unilateral, TEV is slightly more common on the right side. Especially in the severe forms (fixed or rigid TEV), the calf muscles on the affected side are hypotrophic (smaller).

In about half of all cases, TEV occurs alone, or with other related musculoskeletal abnormalities such as torticollis, developmental dysplasia of the hip, and anomalies of multiple joints (e.g. arthrogryposis). TEV can occur with other birth defects, especially those affecting the brain and spine (e.g. spina bifida), through a mechanism thought to involve a deficit of innervation of the limb segments across joints that in turn leads to decreased movement in utero. Multiple deformations that include TEV can occur with genetic conditions that affect the formation of bones and joints (e.g. campomelic dysplasia, Larsen syndrome). More frequently, TEV can occur in chromosomal anomalies such as triploidy, deletion 4p-, and trisomies (though in trisomy 18, the type of clubfoot is calcaneovalgus, with dorsiflexion rather than plantar flexion of the foot).

Non-genetic risk factors reported to be associated with an increased risk for TEV include maternal smoking and possibly very early amniocentesis. In addition, the risk for TEV appears to be multifactorial, in that the recurrence risk for first-degree relatives is 3–6%, and the concordance in monozygotic twins is much higher than in dizygotic twins (30% versus approximately 3%).

The reported birth prevalence is 10–15 per 10 000 births, with moderate variability. Such variability is likely due in part to methodology (ascertainment, inclusion criteria), though ethnicity appears to play a role, with higher reported rates in certain groups (e.g. Maori, Polynesians, Australian Aborigines).


Congenital talipes equinovarus (including congenital, idiopathic, and neurogenic)

Talipes not otherwise specified, clubfoot not otherwise specified (minimize this group)

Q66.0 Talipes equinovarus
Q66.1 Talipes calcaneovarus
Q66.4 Talipes calcaneovalgus
Q66.8 Other congenital deformities of feet, Clubfoot NOS (not otherwise specified)


Clubfoot, positional (exclude; positional talipes is not considered a major defect)

Other presentations of congenital deformities of the foot (e.g. metatarsus varus or valgus, rocker-bottom foot, pes planus, pes cavus, etc.)

Checklist for high-quality reporting

Talipes Equinovarus – Documentation Checklist
Describe in detail, including:
  • Laterality – right, left or bilateral.
  • Mobility of foot – rigid (contracted) versus flexible (flexible is the same as positional, and is excluded in most
  • The typical features of talipes equinovarus (plantar flexion, varus deformity, upward rotation).
  • Related findings if present (medial creases, hypotrophic calf ).
    • Describe other deformations if present (e.g. knees, fingers, elbows) especially if rigid (e.g. in arthrogryposis).
    • Describe procedures to assess further additional malformations; if one or more is present, describe these.
    • Take and report photographs of the anomaly and the entire infant; useful for review but not sufficient as confirmation.
    • Specialty consultations: Report which were done (including genetics and orthopaedics) and results.
    • Note that the following:
      • Flexible/positional talipes equinovarus or other presentations of deformities of the foot are excluded from surveillance tracking because of variability, frequency and minor health impact.
      • Talipes associated with neuromuscular sequences and syndromes are included in surveillance tracking; note that programmes should code the associated clubfoot but should consider whether or not these cases are included in prevalence estimates of talipes.
      • Other presentations of deformities of the foot.

Suggested data quality indicators

Category Suggested Practices and Quality Indicators
Description and documentation Review sample of clinical description for documentation of key descriptors:
  • Description of deformations – equinus, varus, supination.
  • Description of whether the deformation is positional (flexible) or rigid (fixed).
  • Description of related findings (present or absent), on the foot/lower leg (e.g. medial crease, calf hypotrophy), and of other deformations involving other joints.
  • Documentation of whether it is left, right or bilateral.
  • Drawings, photographs and consultation reports
  • Code as Q66.X for specific type, if documented.
  • Monitor and minimize the use of generic code for clubfoot; use Q66.0.
  • Consider adding a sixth digit to identify positional versus rigid talipes equivarus.
Clinical classification
  • Track proportion of congenital anomalies and syndromes occurring with clubfoot; a proportion
    substantially < 30–40% suggests under-ascertainment of clinically important conditions.
  • Monitor prevalence: Prevalence varies moderately, especially by ethnicity, but if very low (< 5 per 10 000 births) it strongly suggests under-ascertainment.
  • Compare prevalence among the smallest site/time units: Statistically significant dissimilar results suggest a possible methodological problem in one or more site/time units.
  • Compare prevalence by ethnicity and compare with expectation.