Updated: 6/17/2021

Osteomalacia

0%
Topic
Review Topic
0
0
Topic
Images
https://upload.orthobullets.com/topic/9033/images/looser zone.jpg
https://upload.orthobullets.com/topic/9033/images/patho frac fem neck.jpg
https://upload.orthobullets.com/topic/9033/images/histo osteomalacia.jpg
https://upload.orthobullets.com/topic/9033/images/histo osteoid.jpg
  • summary
    • Osteomalacia is a metabolic bone disease where defective mineralization results in a large amount or unmineralized osteoid.
    • Diagnosis is made based on a thorough evaluation of serum labs, clinical features, and radiographic findings.
    • Treatment involves medical management with Vitamin D supplementation and resolving the underlying etiology.
  • Etiology
    • Mechanism
      • qualitative defect as opposed to a quanitative defect like osteoporosis
  • Epidemiology
    • Incidence
      • rare in the US (approximately 1 in 1000)
        • much less common than osteoporosis
        • because of adequate exposure to sunlight and dairy products fortified with vitamin D
    • Demographics
      • rickets is found in children (open physis)
      • osteomalacia is found in adults (closed physis)
    • Risk factors
      • the following conditions predispose a patient to osteomalacia
        • vitamin-D deficient diets
        • malabsorption e.g. celiac disease
        • renal osteodystrophy
        • hypophosphatemia
        • chronic alcoholism
        • tumors (tumor-induced osteomalacia)
        • drugs
          • drugs associated with vitamin D deficiency
            • phenytoin
            • phenobarbital
            • rifampin
            • cholestyramine
            • cadmium
            • glucocorticoids
          • drugs affecting phosphate homeostasis
            • aluminium-containing phosphate-binding antacid
            • ifosfamide
          • drugs affecting bone mineralization
            • aluminium
            • etidronate
            • fluoride
  • Presentation
    • Symptoms
      • generalized bone and muscle pain
      • fractures of long bones, ribs and vertebrae
      • proximal muscle weakness weakness
      • fatigue
    • Physical exam
      • inspection
        • waddling gait
          • from hip pain and thigh weakness
        • difficulty rising from chair and climbing stairs
  • Imaging
    • Radiographs
      • findings
        • Looser's zones (insufficiency fractures)
          • medial femoral cortex
          • pubic ramus
          • scapula
        • fractures (especially in the proximal femur/femoral neck)
        • biconcave vertebral bodies
        • trefoil pelvis
        • protrusio acetabuli
    • Bone scan
      • findings
        • increased activity
  • Studies
    • Labs
    • Lab values
      Serum Ca
      Serum P
      Alk phos
      PTH
      25-(OH)vit D
      1,25-(OH)vit D
      Urinary Ca
      Osteomalacia
      Low
      Low
      High
      High
      Low
      Low
      Low
      Osteoporosis
      Normal
      Normal
      Variable
      Normal
      Normal
      Normal
      Normal
      Tumor induced osteomalacia
      Low
      Very low
      Low
      Low
      Low
      Low
      Low
      Osteopetrosis
      Normal
      Normal
      High
      Normal
      Normal
      Normal
      Normal
  • Histology
    • Characteristic histology includes
      • technique
        • requires transiliac biopsy for definitive diagnosis
      • findings
        • widely separated osteoid seams
  • Treatment
    • Nonoperative
      • large doses of oral vitamin D (1000IU/day), treat underlying cause
        • indications
          • most patients
      • technique
        • specific subgroups of patients
          • on long-term anticonvulsant therapy
            • supplement with 400-800IU/day of vitamin D
          • with hepatobiliary disease
            • supplement with 25(OH)-vit D
          • with renal disease
            • supplement with 1,25(OH)2 vit D
Flashcards (0)
Cards
1 of 0
VIDEOS & PODCASTS (1)
EXPERT COMMENTS (18)
Private Note