Bone Bowing
In addition to proximal focal femoral deficiency, pediatric practice frequently encounters various long bone curvatures. These can be either physiological (usually bilateral and resolve without intervention) or pathological — associated with rickets, past trauma, infections, neurofibromatosis, fibrous dysplasia, as well as specific syndromes (Ollier disease, Maffucci syndrome, Blount disease).
The most indicative tibial deformations are:
- Posteromedial bowing (posteromedial bowing). This looks quite alarming on imaging, but most often it is a physiological condition that resolves spontaneously over time.
- Anterolateral bowing (anterolateral bowing). A much more concerning sign. In half of the cases, it is associated with neurofibromatosis type 1, and in 15% with fibrous dysplasia. Such bowing can be complicated by the formation of a false joint (pseudarthrosis) and tends to progress steadily without treatment.
Focal Dysplasia and Blount Disease
These pathologies have clear radiographic patterns affecting predominantly the tibia.
Focal Fibrocartilaginous Dysplasia (Focal Fibrocartilaginous Dysplasia) Most commonly localized in the proximal tibia. It is characterized by a specific radiographic picture: visible deformation with bowing and the presence of a linear radiolucent area (radionegative band) in the cortical layer. This band extends from the proximal metadiaphysis downward and laterally. The process has a benign course and usually regresses on its own. Surgery is rarely required — only for severe or non-resolving deformity.
Blount Disease (Blount Disease) Characterized by varus deformity due to involvement of the medial parts of the proximal tibial epiphysis (unilateral in 40% of cases). Infantile (1–3 years) and adolescent forms are distinguished (the latter more frequently recurs after surgery). Radiographic evolution: initially, a beak-like deformity (beaking) of the medial metaphysis appears, then the contours become irregular, fragmentation occurs, and ultimately — premature closure of the medial portion of the physis.
Upper Extremity and Shoulder Girdle Anomalies
In diagnostic imaging, it is important to be able to recognize classic deformities of the forearm and scapula.
Madelung Deformity (Madelung Deformity) Forms due to premature closure of the inner (medial) half of the distal growth plate of the radius. On radiographs, the radii appear shortened and curved, the carpal angle is reduced, and the carpal bones seem to wedge between the ends of the radius and ulna. This can be a consequence of trauma, infection, or inherited as mesomelic dysplasia (Léri-Weill dyschondrosteosis). There is also a reverse Madelung deformity, in which forearm curvature is accompanied by an abnormally short ulna.
Radial Dysplasia Manifests as aplasia or underdevelopment (hypoplasia) of the radius itself and the structures of the thumb along with its metacarpal bone. It may occur in isolation or as part of severe genetic anomalies: VATER/VACTERL, Holt-Oram, Fanconi anemia syndromes. Secondary causes include the influence of amniotic bands or toxic drug effects (e.g., thalidomide causing phocomelia, or methotrexate).
Sprengel Deformity (Sprengel Deformity) The most common congenital anomaly of the shoulder girdle, caused by a failure of the scapula to descend during the 6th–8th week of intrauterine development. Boys and females are affected with equal frequency (in unilateral forms, the left side is more commonly affected). The scapula is positioned abnormally high on radiographs, rotated (glenoid fossa facing the spine), and increased in size. Sometimes an ophivertebral bone is visualized — a bony or fibrous band between the scapula and the spine. It is frequently combined with Klippel-Feil syndrome (cervical vertebral fusion).
Diagnostic Imaging of Foot Deformities
Evaluation of foot deformities (especially clubfoot — equinovarus deformity) requires strict radiographic measurements. Congenital clubfoot develops around the 9th week of gestation, occurs 2–3 times more frequently in boys, and consists of a combination of hindfoot varus and equinus, as well as forefoot varus.
| Type of deformity | AP view | Lateral view |
|---|---|---|
| Hindfoot varus | Talar-calcaneal angle <15°. Midline of the talus is lateral to the base of the 1st metatarsal bone | Talar-calcaneal angle <25° |
| Hindfoot valgus | Talar-calcaneal angle >50° (neonates) or >40° (older children) | Talar-calcaneal angle >50° (neonates) or >45° (older children) |
| Hindfoot equinus | — | Calcaneal-tibial angle >90° (plantarflexion) |
| Calcaneal deformity | — | Calcaneal-tibial angle <60° (dorsiflexion) |
| Forefoot varus | Narrow foot, significant overlapping of metatarsals | 1st metatarsal bone is located most dorsally |
| Forefoot valgus | Wide foot, overlapping of metatarsals is reduced | 1st metatarsal bone is located most plantarly |
Briefly: answers to topical questions
What classes of proximal focal femoral deficiency are distinguished according to the Aitken classification?
According to the Aitken classification, proximal focal femoral deficiency is divided into 4 groups — from A to D — in order of increasing severity. The assessment criteria include the presence or absence of the femoral head. There is also a correlation between the severity of hip dysplasia and the severity of acetabular dysplasia.
What are the forms of Blount disease and what are their main clinical differences?
Two main forms of Blount disease are distinguished: infantile and adolescent.
| Morphology | Age | Main difference |
|---|---|---|
| Infantile | 1–3 years | — |
| Adolescent (adolescent) | Not specified | Higher recurrence rate after surgical treatment |
Blount disease affects the medial aspects of the proximal tibial epiphysis. In 40% of cases, the involvement is unilateral.
To memorize the connection of Sprengel deformity: "A high scapula (Sprengel) often pulls the neck along with it (vertebral concrescence — Klippel-Feil syndrome)."
Class and exam questions
What is the main difference between anterolateral and posteromedial tibial bowing?
Posteromedial bowing is usually physiological and resolves on its own. Anterolateral bowing is a formidable sign that is associated with neurofibromatosis type 1 in 50–55% of cases, tends to progress, and leads to pseudarthrosis.
What is the essence of Madelung deformity?
It arises due to premature closure of the inner half of the distal radial growth plate. This leads to shortening and curvature of the forearm with impaction of the carpal bones.
What is an omovertebral bone?
This is a pathological bony or fibrous connection between the superomedial angle of a high-riding scapula and elements of the vertebra (spinous process or lamina), which is detected in Sprengel deformity.
What else to study on this topic
- Radiographic signs and classification of Blount disease
- Specifics of foot angle measurements in clubfoot
- Differential diagnosis of focal fibrocartilaginous dysplasia
- Syndromes associated with radial dysplasia (VACTERL, Holt-Oram)
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