Orthopaedic Deformities Quiz

Study Notes

Genu Varum (Bow Legs) in infants:
- Most commonly caused by development and is physiological.
- Usually corrects itself by age 4.
- No treatment is needed.
Genu Varum (Bow Legs) in children aged 1.5-2 years:
- Most commonly caused by rickets due to vitamin D deficiency.
- Symptoms include systemic signs and lab findings.
- Treatment focuses on correcting the underlying cause, often with vitamin D supplements.
- Advanced cases may require osteoclasis or osteotomy.
Genu Varum (Bow Legs) in adults:
- Causes include osteoarthritis, mal-united fractures, ligamentous injuries, and Paget's disease.
- Treatment involves surgical correction of the deformity.
Genu Valgum (Knock Knees) up to age 4:
- Usually developmental or physiological.
- Typically corrects itself by ages 6-8.
- If progressive, supracondylar osteotomy of the femur is required.

Normal neck-shaft angle of the proximal femur is 160° at birth, decreasing to 125° in adulthood.
Coxa Vara: angle less than 110°.
Coxa Valga: angle more than 130°.
Both can lead to gait disability, spinal pain, and deformity.
Treatment is by corrective subtrochanteric osteotomy.

Normal carrying angle is 10-15 degrees of valgus.
Cubitus valgus: angle above 15°.
Cubitus varus: angle below 10°.
These deformities can be surgically corrected with a wedge osteotomy at the lower humerus.

Bone is connective tissue with cells and matrix.
Bone Cells:
- Osteoblasts: form bone.
- Osteoclasts: resorb bone.
Bone Matrix (Osteoid):
- Made of collagen and calcium salts.
Causes of Bone Softening Diseases:
- Defective osteoid formation (e.g. osteogenesis imperfecta)
- Defective osteoid mineralization (e.g. rickets)
- Increased bone resorption by osteoclasts (e.g. hyperparathyroidism)
- Decreased bone formation by osteoblasts (e.g. osteoporosis)

Generalized mesenchymal disorder characterized by:
- Defective osteoid production, resulting in fragile bone and multiple fractures.
- Defective collagen production, causing joint hyperlaxity and blue sclera.
Types of OI:
- Congenital: stillborn or born with multiple fractures.
- Infantile: manifests early in infancy with multiple easy fractures.
- Tarda: manifests in late childhood.
OI Treatment:
- No cure.
- Orthopedic management focuses on:
  - Preventing fractures and deformities using supporting devices.
  - Treating current fractures.
  - Correcting deformities with surgery if needed.

Disease of growing bone due to inadequate calcification of bone matrix.
Causes:
- Infantile: deficient vitamin D intake and lack of sunlight exposure.
- Coeliac: deficient absorption of fat and vitamin D due to gluten intolerance.
- Renal: disturbed calcium-phosphorus metabolism due to renal dysfunction.
Clinical Picture:
- Bony deformities (bow legs, knock knees).
- Characteristic signs of infantile rickets:
  - Boxy-bossy skull
  - Rickety rosary
  - Pigeon chest
  - Harrison Sulcus
  - Broad metaphysis
  - Marfan sign
10 Important Clinical Features:
- Delayed closure of fontanelles
- Frontal bossing
- Dental hypoplasia
- Pectus carinatum
- Swelling in wrist and ankle joints
- Wide sutures
- Craniotabes
- Rachitic rosary
- Harrison's sulcus
- Bowing of legs
X-ray:
- Bone rarefaction, broadened and cupped metaphyses with a brush border.
Treatment:
- Infantile rickets: vitamin D, calcium, good diet, sunlight exposure.
- Renal rickets: active vitamin D (one alpha) and calcium.
- Severe deformities: surgical correction (osteotomy) may be needed.

Primary hyperparathyroidism: increased parathyroid hormone secretion due to hyperplasia or tumor.
Causes increased bone resorption leading to:
- Hypercalcemia.
- Recurrent renal calculi.
- Cystic changes in bones, deformities, and pathological fractures.
Treatment: surgical excision of parathyroid adenoma.

Diminished bone mass due to decreased bone formation by osteoblasts with aging and menopause.
Common Affected Sites:
- Vertebral column: causes vertebral collapse, back pain, kyphosis, and wedged or biconcave vertebrae on x-ray.
- Proximal femur.
- Proximal humerus.
- Distal radius (prone to fractures after minor trauma).
Diagnosis: bone densitometry (DEXA).
Treatment:
- Adequate diet (calcium, vitamin D, protein).
- Daily exercise and sunlight exposure.
- Medications:
  - Calcium, vitamin D.
  - Calcitonin (increases osteoblastic activity).
  - Bisphosphonates (inhibit osteoclastic activity).
  - Hormone replacement therapy (HRT) in some cases.