2. Plan
• Introduction – Defining the subject
• (1): Pathogenesis
• (2): Clinical Presentation and Diagnosis
• (3): Treatment and Prevention
• Conclusion
3. Defining the disease
• Rickets – word’s orginin is unknown
– Maybe Rucket – to breath with difficulty, Dorset
word
– Or Rhakhis – Spine, Rhachitis ‘’inflammation of
spine’’
Definition: A deficiency disease resulting from a lack of
vitamin D or calcium and from insufficient exposure to
sunlight, characterized by defective bone growth and
occurring chiefly in children. Also called rachitis.
The American Heritage® Dictionary of the
English Language
4. Normal Bone Processes
• Calcium and Phosphate
– Constitutes the crystalline component of bone
• Deficiency leads to disease (i.e., Rickets and/or
osteomalacia)
• Rickets:
– Deficient mineralization at growth plate
• Osteomalacia:
– impaired mineralization of the bone matrix.
• Open plates: Occur in Osteomalacia and rickets.
• Closed plates: Happens in osteomalacia only!
5. Mineralization Defects
• Classified according to Predominant mineral
deficiency:
– 1) Phosphopenic (hypophosphatemic) rickets
• Primarily caused by phosphate deficiency
– 2) Calcipenic (hypocalcemic) rickets
• Primarily caused by calcium deficiency
Associated with decrease levels of phosphorus or
calcium, respectively.
6. Pathogensis
• Growth Plate thickens:
– Chondrocytes grow and hypertrophy
– Vascular invasion of growth plate into primary bone
• Vascular invasion requires mineralization of the growth plate
cartilage
• Can be delayed or prevent by deficiency of calcium or
phosphorous
• In such circumstances growth plate cartilage accumulates
and thickens. In addition, the chondrocytes of the growth
plate becomes disorganised, losing their regular straight
columned orientation.
7. The Pathogenic processes..
Osteoid Accumulation in metaphysis
Decreased biochemical resistance of the
invovled skeletal sites
2nd-ary inc- diameter of the growth plate.
Compensatory mechanism due to decrease
strenght by increase size
Bone stability is compromised - if such
condition does not improve, bowing occurs.
8. Pathogenesis (Normal) [2]
Proliferation of
chondrocytes
Calcification and
vascular invasion
Reserve
zone
Maturation
zone
Proliferative
zone
Hypertrophic
zone
Primary
spongiosa
2. Shapiro IM, Boyde A. Mineralization of normal and rachitic chick growth cartilage: vascular canals, cartilage
calcification and osteogenesis. Scanning Microsc 1987; 1:599.
9. Pathogenesis (Rickets) [3-6]
Proliferation of
Thick + Disorganized
chondrocytes
cartilage
Less calcification and
vascular invasion
Hypertrophic
zone
3. Lacey DL, Huffer WE. Studies on the pathogenesis of avian rickets. I. Changes in epiphyseal and metaphyseal vessels in hypocalcemic and hypophosphatemic rickets.
Am J Pathol 1982; 109:288.
4. Huffer WE, Lacey DL. Studies on the pathogenesis of avian rickets II. Necrosis of perforating epiphyseal vessels during recovery from rickets in chicks caused by
vitamin D3 deficiency. Am J Pathol 1982; 109:302.
5. Takechi M, Itakura C. Ultrastructural studies of the epiphyseal plate of chicks fed a vitamin D-deficient and low-calcium diet. J Comp Pathol 1995
6.. Rauch F. The rachitic bone. Endocr Dev 2003; 6:69.
10. Clinical manifestation
• Usually @
distal forearm, knee, and costochondral
junctions.
• Typically @
Sites of rapid bone growth, where large
quantities of calcium and phosphorus are
required for mineralization.
11. Clinical Manifestations (Skeletal) [13]
1. Delay in closure of the fontanelles
2. Parietal & frontal bossing (due to excess osteoid)
3. Craniotabes ( soft skull bones)
4. Enlargement of the costochondral junction
(rachitic rosary)
5. The development of Harrison sulcus ( caused by pull of the diaphragmatic attachments
to the lower ribs)
6. Pigeon chest deformity (The weakened ribs bend inwards due to the pull of respiratory
muscles, causing anterior protrusion of sternum)
7. Enlargement of the wrist + ankle & bowing of the distal radius & ulna
8. Genus Valgus (knocked), Genus Verus (bowleg), or Windswept deformity (combination
of valgus deformity of 1 leg with varus deformity of the other leg)
13. Misra M, Pacaud D, Petryk A, et al. Vitamin D deficiency in children and its management: review of current
knowledge and recommendations. Pediatrics 2008; 122:398.
Pictures from http://www.thachers.org
12. Clinical Manifestations (Extra-Skeletal)
• Depends upon the type of ricket
• Hypoplasia of the dental enamel is typical for hypocalcemic rickets,
whereas abscesses of the teeth occur more often in phosphopenic rickets.
• Hypocalcemic seizures, decreased muscle tone leading to delayed motor
milestones, recurrent infections, increased sweating
13. Clinical Manifestations
• GENERAL Failure to thrive; Protuding abdomen;
Muscle weakness (especially proximal); Fractures
• HEAD Craniotabes; Frontal bossing; Delayed
fontanelle closure; Delayed dentition; caries
• CHEST Rachitic rosary; Harrison groove; or
Respiratory infections
• BACK Scoliosis ,Kyphosis ,Lordosis
• EXTREMITIES Enlargement of wrists and ankles;
Valgus or varus deformities Windswept deformity
(combination of valgus deformity of 1 leg with
varus deformity of the other leg); Anterior bowing
of the tibia and femur; Leg pain.
• HYPOCALCEMIC SYMPTOMS Tetany, Seizures;
Stridor due to laryngeal spasm
14. Chest radiograph of a patient with rickets,
demonstrating a "rachitic rosary". Observe the
opaque, bulbous indentations of the lung
adjacent to the enlarged costochondral
junctions (arrows).
Bilateral, symmetric bowing of the
femurs and tibias.
15. Radiography
• Best visualised @ growth plate of rapidly
growing bones.
– Upper limb distal Ulna
– Knee Metaphyses above and below
16. As disease progresses:
Disorganization of the growth plate becomes
more apparent:
1) with cupping,
2) splaying,
3) formation of cortical spurs
4) stippling.
20. Biochemical Findings in Rickets
• Alkaline phosphatase: ↑in all forms of rickets
• Serum phosphorus: ↓ in both hypocalcemic and phosphopenic rickets (normal 5-
7mg/dl)
• Serum Ca+2: ↓in hypocalcemic rickets (normal 9-11mg/dl)
• Serum PTH: ↑in hypocalcemic rickets, but normal in hypophosphatemic rickets
• 25-OH vitamin D reflect the amount of vitamin D stored in the body, and is ↓in
vitamin D deficiency.
• 1,25-OH2 vitamin D can be↓, N or ↑in hypocalcemic rickets and usually is N or
slightly ↑in phosphopenic rickets
21. Labs
• Alkaline phosphatase is increased markedly
over the age-specific reference range.
• Excellent marker – participates in mineralization of
bone and growth plate cartilage.
22.
23. Evaluation
• A child with clinical signs of rickets should
include dietary history with particular
attention to given calcium and vitamin D
intake
• Medication history
• Measurement of serum creatinine and live
enzymes
24. Treatment of Rickets
• EITHER: Vitamin D. stoss therapy: 300,000-600,000 IU orally or IM in 2-4
divided doses over one day
• OR: High dose vit D 2000-5000 IU orally for 4-6wks followed by 400 IU
daily orally as maintenance
• OR: (5000-10,000 U) is given daily for 2-3 months until healing and alkaline
phosphatase concentration is approaching to the normal
• Adequate dietary Calcium & phosphorus provided by milk, formula &
other dairy products
• Symptomatic hypocalcaemia need IV CaCl as 20mg/kg or Calcium
gluconate as 100mg/kg as a bolus, followed by oral calcium tapered over
2-6 weeks
25. PREVENTION
1.Exposure to sunlight (ultraviolet light)
Early morning and evening 15 minutes per day
2. Lactating mothers should receive supplemention
with milk or vitamin D to ensure prevention of rickets in
their babies.
3. Sun exposure to mothers
26. Prevention
4. Vitamin D supplementation (careful of toxicity):
In prematures, twins and weak babies, give Vitamin D
800IU per day
For term babies and infants the demand of Vitamin D
is 400IU per day
28. Outcome
• Good news:
– Mostly reversible
– Some deformities might persist
29. Conclusion
• Rickets refers to the changes at the growth
plate caused by deficient mineralization of
bone. Happens only before growth plates
closure.
• 2 types of rickets
• Skeletal findings + Extra skeletal findings
• Certain radiographic findings
