Imaging in rickets

Rickets is a metabolic disease of growing bone that is � unique to children.
It caused by a failure of mineralization of osteoid tissue in a � developing skeleton, particularly at the growth plate.
Imperfect calcification typically resulting in soft bones and � skeleton deformities.

1. IMAGING IN RICKETS Presenter: dR. Yashas ullas l .

2. Contents Pathoradiological features Radiological features Differential diagnosis

3. Introduction Rickets is a metabolic disease of growing bone that is unique to children . It caused by a failure of mineralization of osteoid tissue in a developing skeleton, particularly at the growth plate. Imperfect calcification typically resulting in soft bones and skeleton deformities.

4. Patho radiological features Radiological appearances truly portray the histological changes occurring in the bones. Disordered proliferation of cartilage cells and defective mineralization in the zone of provisional calcification. Decreased quantity of calcified osteoid.

5. Patho radiological features Owing to the lack of osteoid mineralization the metaphyseal zone of provisional calcification will also be absent radiographically. Bones appear more radiolucent with coarsened trabecular pattern. Widened growth plate with irregular, frayed and cupped metaphyseal margins (paintbrush metaphyses )

6. Apoptosis of hypertrophic chondrocytes caused by phosphate ions Hypophosphatemia No apoptosis of hypertrophic chondrocytes Normal growth plate Rachitic growth plate

7. Impaired apoptosis of terminally differentiated chondrocytes in the growth plate are responsible for clinical and radiological signs of rickets

8. RADIOLOGICAL FEATURES Widening of growth plate:- Earliest and specific radiological change. It is due to increase in cartilaginous cell mass. Metaphyseal fraying:- Irregular metaphyseal margins occurring due to fraying and disorganization of spongy bone in the metaphyseal region.

9. RADIOLOGICAL FEATURES Metaphyseal cupping and widening:- Protrusion of bulky mass of cartilageneous cells in the zone of hypertrophy into the poorly mineralized metaphysis. Normal Rickets

10. RADIOLOGICAL FEATURES Epiphyseal abnormalities:- Osteopenia. Irregular and indistinct borders. Delayed appearance of ossification centres. Shaft abnormalities:- Rarefaction of shaft due to loss of mineral content. Cortex becomes thin with coarse echotexture.

11. RADIOLOGICAL FEATURES Growth plate abnormalities:- Generalised osteopenia. Coarse trabecular pattern. Frayed paintbrush metaphyseal margins. Lack of the zone of provisional calcification. Widening of the physis .

12. RADIOLOGICAL FEATURES Wrist: Widening of growth plates. Irregular margins of metaphysis with widening and cupping. Osteopenia. Rarefraction in long bones.

13. RADIOLOGICAL FEATURES Bowing of long bones: Result of displacement of growth centres owing to assymetrical musculotendinous pull on the weakened growth plate.

14. RADIOLOGICAL FEATURES Rachitic rosary: Bulbous enlargement of costochondral junction. May indent on the pleural surface.

15. RADIOLOGICAL FEATURES Craniotabes : Excessive osteoid deposition in frontal and parietal regions with posterior flattening of skull due to supine posture of infant. Squared configuration of skull. Demineralisation of skull.

16. RADIOLOGICAL FEATURES Triradiate pelvis:- Protrusion of hip into the soft pelvis with protrusio acetabuli.

17. RADIOLOGICAL FEATURES OF HEALING RICKETS Appearance of line of provisional calcification at the end of metaphysis. Metaphysis show cupping and splaying but no fraying. Periosteum may show double periosteal line due to subperiosteal deposition of osteoid tissue.

18. RADIOLOGICAL FEATURES OF HEALED RICKETS The subperiosteal osteoid tissue is calcified (no double periosteal line). Splaying and cupping is corrected.

19. Before After

20. Differential diagnosis Scurvy. Schimid type metaphyseal chondrodysplasia . Blount disease.

21. Differential diagnosis Rickets Scurvy Epiphyseal centres are invisible or indistinct Epiphysis is sharply marginated by sclerotic rim ( Wimberger’s sign) Loss of zone of provisional calcification adjacent to metaphysis, thus having a faint and irregular line (Fraying) Zone of proviosional calcification at metaphysis is dense giving a “ White line of Frenkel’s sign” Not found Trummerfeld zone and Pelken’s spur seen Subperiosteal layer may be found but less marked effect. Sub-periosteal hemorrhage due to capillary fragility giving rise to periosteal; elevation.

22. Differential diagnosis RICKETS SCURVY Epiphyseal centres are invisible or indistinct Epiphysis is sharply marginated by sclerotic rim ( Wimberger’s sign) Loss of zone of provisional calcification zone of provisional calcification is dense “White line of Frenkel ”

23. Differential diagnosis Schimid type metaphyseal chondrodysplasia - Mild type, due to mutation in type X collagen ( COL10A1  gene), metaphyses are cupped resembling rickets.

24. Differential diagnosis Blount disease refers to a local disturbance of growth of the medial aspect of the proximal tibial metaphysis and/or epiphysis that results in tibia vara .