Rickets is a defect in bone mineralization that occurs before cessation of growth. It is caused by insufficient levels of calcium and phosphorus, which impairs the mineralization of bone and cartilage. The disease is characterized by defective mineralization, retarded bone growth, and abnormalities in the growth plates of long bones. It has diverse etiologies, but is commonly caused by vitamin D deficiency resulting from inadequate intake, absorption or metabolism. Other causes include deficiencies in calcium, phosphorus, and certain renal tubular disorders. The presentation involves bone deformities, softening of the skull, rib protrusions, and fractures. Diagnosis is made through physical exam findings, x-rays showing changes in bone structure and density, and

1. DR RITESH JAISWAL
M.B.B.S D.Ortho DNB (Ortho) M.N.A.M.S M.Ch (Ortho)
Fellowship in Joint Replacement ( Mumbai )
Fellow AO Trauma ( Switzerland )
RICKETS

2. INTRODUCTION
RICKETS is a defect in bone mineralization that occurs
before cessation of growth.
(osteomalacia is a defect in bone mineralization after the cessation of growth)
It is the most common metabolic disease of the bone encountered in children in
developing countries .
Condition with diverse etiology characterized by failure of
normal mineralization of bone and epiphyseal cartilage
and by skeletal deformity occuring in children
In children the epiphyseal ends of the bones are the most
active in osteogenesis, hence disease is more evident there

3. Rickets is characterized by
- defective mineralization of cartilage and osteoid
- Retarded endochondral ossification
( *Failure of normal apoptosis of hypertrophic chondrocytes ,
causing ossification defect )
Abnormalities of mineralization and ossification are
due to insufficient circulating levels of calcium &
phosphorus
Defect in endochondral ossification more specifically
Occurs due to hypophosphatemia , which impairs
chondrocyte apoptosis

4. MINERAL HOMEOSTASIS
CALCIUM
FUNCTIONS :
- Normal cell function
- Blood coagulation
- Nerve conduction
- Muscle contraction
Bone
- 98% of the body’s calcium
- 85% of its phosphorus
Bony skeleton acts as a reservoir of stored calcium and can be drawn
upon to maintain serum levels.
Sources :
- Dairy products
- Green vegetables and soya (or fortified foods)
Recommended daily intake :
- Children 200–400 mg per day
- Adults is 800–1000 mg
- Pregnancy and Lactation 1200 mg during

5. - 50% of the dietary calcium is absorbed (mainly in the upper gut) but much of
that is secreted back into the bowel and only about 200 mg (5 mmol) enters
the circulation.
- Normal concentration in plasma and extracellular fluid is 2.2–2.6 mmol/L
(8.8–10.4 mg/dL).
- Much of this is bound to albumin as well as other proteins
- About half (1.1 mmol) is ionized and effective in cell metabolism and the
regulation of calcium homoeostasis.
Absorption
- ↑ by vitamin D ( 1,25-(OH)2 vitamin D
- ↓ by excessive intake of
- phosphates (common in soft drinks)
- oxalates (found in tea and coffee)
- Phytates (chapati flour)
- certain drugs (including corticosteroids)
- malabsorption disorders of the bowel

6. Urinary excretion varies between 2.5 and 5 mmol (100–200 mg)
per 24 hours. If the plasma ionized calcium concentration falls, PTH is
released and causes
(a) increased renal tubular reabsorption of calcium and reduced renal
tubular reabsorption of phosphate
(b) a switch to increased 1,25-(OH)2 vitamin D production and enhanced
intestinal calcium absorption.
* If the calcium concentration remains low, calcium is drawn from the
skeleton by increased bone resorption through the influence of PT

7. - Disturbances in the metabolism of calcium (Ca) and phosphate
(PO4) can lead to metabolic bone disease (MBD) with
inadequate mineralization of bone matrix.
- The level of calcium in the serum is regulated by
three hormones:
- vitamin D
- parathyroid hormone (PTH)
- calcitonin.

8. VITAMIN D
Sources of vitamin D are:
1. Diet (inactive form )
- vitamin D2 (ergocalciferol)
- Vitamin D3 (cholecalciferol).
2. The liver also produces 7-dihydrocholesterol (provitamin D),
which is converted to vitamin D3 in the skin as a result of
exposure to ultraviolet light.
*Melanin competes with 7- dihydrocholesterol, such that people who are
heavily pigmented require a longer exposure to ultraviolet light to produce an
equivalent quantity of vitamin D.
*The recommended dietary allowance of vitamin D for children is 400 IU

9. Inactive vitamin D undergoes hydroxylation :
- Liver to form 25-hydroxycholecalciferol
- Kidney to form 1,25- dihydroxycholecalciferol or 24,25-
dihydroxycholecalciferol).
1,25-dihydroxycholecalciferol is also called calcitriol
or the active form of vitamin D
Several medications, such as antiepileptics, can
inhibit this process, leading to vitamin D deficiency.
Vitamin D acts on the intestine and bone and may
have some action on the kidneys

10. VITAMIN D METABOLISM
Skin + UV light vitamin D2 Diet vitamin D2 & D3
↓
Vitamin D2 & vitamin D3
Liver - 1st hydroxylation
↓
25-hydroxycalciferol (inactive vitamin D)
↓
25-hydroxycalciferol
Kidneys - 2nd hydroxylation
↓
1,25-dihydroxycholecalciferol (active vitamin D)
24,25-dihydroxycholecalciferol (inactive vitamin D)
−−−−−−−−−−−−−−−−−──────────────────────────−−−−−−−−−−−
↓ ↓
1 ↑ Gl Ca absorption ↓ 1,25-dihydroxycholecalciferol
(active vitamin D) production
2 ↑ Renal Ca resorption
3 ↑ Bone Ca mobilization

12. PARATHORMONE
PTH is the major regulator of extracellular calcium level acting on :
- Renal tubules
- Renal parenchyma
- Intestine
- Bone
PTH is produced by the parathyroid glands.
Secretion is regulated by plasma ionized calcium
This regulation is mediated by the calcium-sensing receptor Ca SR

13. On renal tubules :
- PTH increases phosphate excretion by restricting its
reabsorptio
- Conserves calcium by increasing its reabsorption.
*These responses rapidly compensate for any change
in plasma ionized calcium
On renal parenchyma :
- PTH controls hydroxylation of the vitamin D metabolite 25-
OHD
- A rise in PTH concentration stimulates conversion to the
active metabolite 1,25-(OH)2D and a fall in PTH causes a
switch towards the inactive metabolite 24,25-(OH)2D

14. On the intestine :
- PTH has the indirect effect of stimulating calcium
absorption by promoting the conversion of 25-OHD to
1,25-(OH)2D in the kidney
On bone :
- PTH acts to promote osteoclastic resorption
and the release of calcium and phosphate into
the blood.
- By stimulating osteoblastic activity, increased expression
of RANKL and diminished production of osteoprotegerin
(OPG).
- Furthermore, the PTH induced rise in 1,25-(OH)2D has the
effect of stimulating osteoclastogenesis.
- The net effect of these complex interactions is a prolonged
rise in plasma calcium

17. ETIOLOGICAL CLASSIFICATION OF RICKETS
Ι. Deficiency Rickets
A. Vitamin-D deficiency
B. Calcium deficiency
C. Phosphorus deficiency
D. Chelators in diet
II. Absorptive Rickets
A. Gastric abnormalities
B. Biliary disease
C. Enteric absorptive defects
III. Renal Tubular Rickets
A. Proximal tubular lesions
B. Proximal and distal tubular lesions
C. Distal tubular lesions (renal tubular acidosis)
1. Primary
2. Secondary
IV. Renal Osteodystrophy
V. Unusual Forms of Rickets
A. Rickets with fibrous dysplasia
B. Rickets with neurofibromatosis
C. Rickets associated with soft-tissue and bone neoplasms
D. Rickets due to anticonvulsant medication
E. Hypophosphatasia

18. VITAMIN D DEFICIENT RICKETS
Decreased intake of Vitamin D
↓
Decreased 1,25 (OH)2 Vitamin D
↓
Decreased GI absorption of Ca++
↓
HYPOCALCEMIA →→→→→→→→→→→→→→→→→→→→→→→→↓
↓ ↓
Secondary hyperparathyroidism →→→→→→→→→→→→→→→→→→→→→ ↓
↓ ↓
Decreased tubular resorption of phosphate ↓
↓ ↓
Hyperphosphaturia ↓
↓ ↓
Hypophosphatemia ↓
↓ ↓
POOR MINERALIZATION OF BONE & ABNORMAL
EPIPHYSEAL PLATE

19. PATHOPHYSIOLOGY
Stage 1 : ↓ intestinal absorption of calcium
↓
Hypocalcemia
(clinically silent or seizures rarely )
Stage 2 : Sec Hyperparathyroidism
↓
↑ mobilizing Ca & P from bone
↑Renal Ca reabsorption & PO4 excretion
( Normalize s.caicium, ↑PTH & Alk PO4,
Hypophosphatemia )
Physeal manifestation of Rickets becomes apparent
Clinicoradiologically

20. Stage 3 :
Worsened Vit D Def , despite PTH
stimulation enters into this stage
↓
↓ Intestinal calcium absorption
Return of hypocalcemia
worsening of sec hyperparathyroidism
↓
Florid Rickets
Clinicoradiologically

21. GROWTH PLATE ZONES

24. CLINICAL PRESENTATION

26. CRANIOTABES
CAPUT QUADRATUM

27. RACHITIC ROSARY
HARRISON SULCUS
Indentation of softened lower
Ribcage at the site of attachment
Of the diaphragm

28. DEFORMITIES
- Bow legs
- Knock knees
- Genu Varum
- Coxa Vara
- Thickening of wrist & ankle
- Pathological fracture

29. INVESTIGATIONS
- History & Physical examination findings
- Radiographic abnormalities
- Biochemical abnormalities

30. RADIOGRAPHS
XRAYS OF WRIST , HIP, KNEE & ANKLE JOINTS

33. Laboratory values
- low to normal serum calcium
- low serum phosphate
- elevated alkaline phosphatase
- elevated parathyroid hormone
- low vitamin D

34. VDDR TYPE 1

35. VDDR TYPE 2

37. RENAL TUBULAR RICKETS
Different renal tubular abnormalities causing hypophosphatemic
rickets having resistance to vitamin D to varied extent
PATHOGENESIS : - 2 theories
1 ) Renal tubular deficit is primarily genetic due to which Vitamin
D cannot cause phosphate reabsorption whereas calcium
absorption is normal in gut.
2 ) Either defect in hydroxylation of vitamin D or end organ
insensitivity to vitamin D ( Primary lesion is calcium deficiency
leads to increase in PTH which causes phosphate wastage )

38. PATHOPHYSIOLOGY
1) Increase phosphate clearance due to decrease
reabsorption
2) Failure to produce H ion andits substitution with
fixed base in distal tubules
3) Failure of conversion of 25 OH D to 1,25 OH

39. RENAL TUBULAR RICKETS : 3 categories
A) Proximal Tubular Lesion
B) Distal Tubular Lesion
C) Proximal & Distal Tubular Lesion

40. PROXIMAL TUBULAR LESIONS
1) Classical Vit D Resistant Rickets
( Hypophosphatemic Rickets / PO4 diuresis )
commonest form
X linked hypophosphatemic rickets – Primary mode of inheritance
X linked dominent. Defective PHEX gene which is required to
inactivate FGF23
In presence of defective PHEX there is increase FGF 23 leading to
abnormality
Most striking feature – failure to respond to Vit D even with
massive doses.

41. 2) VDRR WITH GLYCOSURIA
Hypophosphatemic rickets with glycosuria without
diabetes or pancreatic disease
3) PROXIMAL FANCONI SYNDROME
Phosphate , Glucose & AA wastage.
Serum AA is normal
Disease is more florid but less refractory to treatment
with Vitamin D
4) Rare type manifested in adulthood due to defective
PTH action on tubules.

42. PROXIMAL & DISTAL TUBULAR LESION
Features are common as syndrome :
- Aminoaciduria with normal Serum AA
- Dehydration
- Alkaline Urine ( Bicarbonate loss )
- Acidosis
- Hyperchloremia
- Hyponatremia
- Hypokalemia

43. 1) PROXIMAL & DISTAL FANCONI SYNDROME
- Due to anatomical defect in renal tubules
- Autosomal Recessive , less refractory to treatment
- May be secondary to multiple myeloma or toxic drug
reaction
- Epiphyseal plate several centimeter in height
2) LIGNAC FANCONI SYNDROME ( CYSTINOSIS )
- Metabolic abnormality as above with cystine deposition
throughout soft tissue .
- Difficult to treat & patient rarely survives beyond 10 years of
age despite adequate treatment

44. 3) OCCULOCEREBRAL SYNDROME / LOWE’s SYNDROME
- Features of Rickets, undescended testis, CNS
abnormalities, MR, Hypotonia, Dyskinetic movements,
Nystagmus, Megalocornea, Glaucoma
- Mixture of glomerular, PT, DT lesion metabolic
abnormalities
- Less refractory to treatment
4) SUPERGLYCINE SYNDROME
- Hypophosphatemic rickets with hyperglycinuria

45. RENAL TUBULAR ACIDOSIS - 2 types
1 ) TYPE 1 – Distal Tubular Lesion
Hyponatremic hypokalemic hyperchloremic normal
anion gap metabolic acidosis with alkaline urine
2 ) TYPE 2 – Proximal Tubular Lesion
Hyponatremic hypokalemic hyperchloremic normal anion
gap metabolic acidosis with acidic urine & dehydration

46. PATHOPHYSIOLOGY
Cause of bone lesion is excretion of calcium as
fixed base cause chronic hypocalcemia secondary
hyperPTH which causes Bicarbonate loss and
mobilization of calcium from bone due to acidosis .
Intestinal absorption of calcium is reduced due to
decreased synthesis of 1,25 Vit D
Nephrocalcinosis due to chronic hypercalciuria and
decreased citrate excretion in urine

47. RENAL OSTEODYSTROPHY
Chronic glomerular disease resulting in renal insufficiency ,
azotemia, & acidosis has profound effect on skeletal system
which includes Rickets, Osteomalacia, osteitis fibrosa
cystica, osteoporosis,osteosclerosis & metastatic
calcification.
Reduction in renal mass leads to poor conversion of 25 D to
1,25 D which leads to poor absorption of calcium from gut

48. • Renal excretion of calcium ↓/N, probably
reflecting the ↓ glomerular flow and contraction
of extracellular pool ( < 60 mg /24 hr )
• Fecal excretion of calcium ↑ due to decreased
transport across gutwall
• Serum calcium levels are often N/↓ but marked
hypocalcemia is unusual, since uremic patient is
acidotic & hypoalbumenic – both contributes to
increase in total calcium in ionized form so
hypocalcemic tetany is a rare finding although
total calcium is less.

49. Po4 levels are raised caused by decreased
glomerular filtration.
PTH levels are raised due to feedhack stimulus from
hypocalcemia & hyperphosphatemia
Urinary po4 loss is increased presumably because
of ↑PTH levels
Metabolic changes result in classical osteitis fibrosa
cystica by favoring the formation of labile calcium
carbonate at the expense of more stable calcium apatite.

50. OSTEOSCLEROSIS - Theories
- Exaggerated response of bone during healing
phase with excessive amount of osteoid being
laid down & mineralized
- In uremic osteodystrophy a factor elaborated
by PTH acts to increase bone formation rather
than decreasing it.
- Can be because of sporadic period of
excessive treatment with calcium, vitamin D or
both

51. SOFT TISSUE CALCIFICATION
Metastatic calcification usuall results from ↑
conc. Of calcium & Po4 more than solubility
product of caHPo4 favoured by acidosis,
prolonged bed rest.
Clinical Features :
- Unless the child is severe ill classical features of
rickets are present, craniotabes & frontal
bossing are less common

52. Bowing is common
Prone to epiphyseal separation & metaphyseal Fracture
SCFE
Palpable arteries due to calcification
X Rays
Oteitis fibrosa cystica
Diffuse rarefaction of bone
Subperiosteal resorption of cortices particularly in small
bones of hand & feet
Brown tumors – are cystic areas in shaft of long & flat
bones
Compression Fractures of vertebra
Osteosclerosis of spine – Rugger jeresy spine
Vascular & soft tissue calcification on xrays

53. Rugger jersey spine
Lateral indentation of acetabulum
( TREFOIL PELVIS )

54. Secondary hyperparathyroidism

55. TREATMENT
- No simple regimen
- Need to be tailored as per need of patient
- Treatment include combination of Vitamin D,
calcium, PO4, Alkalinizing solution
- Orthopaedic measures to correct deformities
that cannot be expected to improve with
growth.

56. STANDARD REGIME
1) 1000-2000 IU of vitamin D3 orally per day
(until radiographic improvement is seen)
↓
400 I U / day
2 ) 8000-16000 I U of vitamin D3 orally per day
(until radiographic improvement is seen)
↓
400 I U / day

57. 3) STROSS THERAPY
600000 IU of Vit D3 orally in 6 divided doses ( 100000 IU / dose )
every 2 hourly over 12 hour period
↓
400 IU /day vitamin D3
4) 150000 – 300000 orally as single dose
5 ) 600000 I U Intramuscularly as a single dose
↓
400 I U / day

58. Estimated daily requirement of vit D
- Children – 200 – 400 IU
- Adult – 100 – 400 IU
- I mg of vit D = 40,000 IU
- 1 u gm = 40 IU
Always ensure adequate calcium
supplementation ( 1-1.5 gms/day ) during
therapy to avoid Hungry bone Syndrome

59. - Role of I/V calcium is to treat acute
hypocalcemic tetany or cardiac failure
- Alkalinizing solution
- sodium bicarbonate
- Shohl’s solution
( Citric acid + sod. Citrate )

60. EVALUATION OF TREATMENT
- Serial measurement of Alkaline PO4
- Serial Serum PO4 level
- Serial Radiograph to see signs of healing
- Treatment is considered to be adequate when
- serum Alkaline PO4 comes to normal range
& radiograph show signs of healing
- If radiographs are not showing signs of healing
after 4-6 wks of traetment it should be
considered as refractory rickets

61. DIAGNOSING POTENTIAL SIDE EFFECTS OF
TREATMENT
- Serial measurement of s.calcium and urinary
calcium excretion
- S. calcium > 11 mg/dl
- Urinary Calcium > 250 mg/24 hrs
- Can lead to nephrocalcinosis and soft tissue
calcification
- Urinary calcium < 100 mg/dl indicates inadequate
treatment

62. Orthopaedic measures
- If treatment started earlier
deformities correct
spontaneously
- Long standing cases & Vit D
Resistant Rickets
- Mild deformity – Bracing
- ( mermaid splint for knock knees )
- Severe deformity - Osteotomies

64. THANKS
FOR YOUR
ATTENTION