Osteopetrosis

osteopetrosis,INTRODUCTION ,types,cloinical features radiological findings

1. OSTEOPETROSIS BY –Dr. MADHAVAN

2. LESSON PLAN Name of the lecturer :Dr. MADHAVAN Date : 18/06/2020 Class: Orthopaedic postgraduates, interns and UG students Number of students : 24 Time : 8mins Subject : Orthopaedics Topic :OSTEOPETROSIS

3. SPECIFIC LEARNING OBJECTIVES Each Students should be able to Describe the definition, etiology, pathogenesis, types and clinical presentation of Osteopetrosis Describe the modalities of investigations with its classical radiological findings, management and complications of Osteopetrosis At the end of the class, With out mistakes

4. Sl no Content Method and media Time taken Evaluation 1 EPIDEMIOLOGY AETIOLOGY PATHOGENESIS Power point presentation 3 Questions and answers 2. TYPES OF OSTEOPETROSIS CLINICAL FEATURES Power point presentation 2 Questions and answers 3. TREATMENT DIAGNOSIS Power point presentation 3 Questions and answers Assignment :All students should able to find the classical radiological findings in Osteopetrosis

5. INTRODUCTION The term osteopetrosis is derived from the Greek ‘ Osteo ‘ means BONE and ‘ Petros ' means STONE . ‘ Marble bone disease ‘ ‘ Albers- Schönberg disease ‘ After the German radiologist credited with the first description of the condition in 1904

6. EPIDEMIOLOGY Autosomal recessive : 1 in 250,000 births Autosomal dominant: 5 in 100,000 births Demographics genetic inheritance (3 types) Malignant autosomal recessive Benign autosomal dominant ( mostcommon ) Intermediate autosomal recessive

7. AETIOLOGY Mutations in the CLCN7  : 75% Autosomal dominant  osteopetrosis TCIRG1 gene mutations: 50% Autosomal recessive(malignant)  osteopetrosis .

8. Mutations in any of the genes lead to abnormal or missing osteoclasts . old bone is not broken down as new bone is formed. As a result, bones throughout the skeleton become unusually dense which is hallmark finding in xrays . PATHOGENESIS

9. leads to dense bone Osteoclast dysfunction  obliterated medullary canals Followed by  osteoclast  inability to acidify Howship's lacuna 

10. PREDISPOSITION TO FRACTURE   lower extremity > upper extremity > axial skeleton Carpal tunnel syndrome

11. ASSOCIATED CONDITIONS   Head Cranial nerve palsies Due to overgrowth of skull foramina Optic n. > auditory n.  > trigeminal n. > facial n

12. Spine:  

13. Pelvis: coxa vara Due to femoral neck fracture nonunion or repeated stress fractures

14. MALIGNANT AUTOSOMAL RECESSIVE INTERMEDIATE AUTOSOMAL RECESSIVE BENIGN AUTOSOMAL DOMINANT

15. TREATMENT Bone marrow transplant High dose calcitriol (1,25 dihydroxy vitamin D). Interferon gamma-1beta Neurosurgical decompression

16. FRACTURE MANAGEMENT Prolonged casting and non-weight bearing In Proximal femur fractures Plate and screws Avoid intramedullary devices

17. GENETIC COUNSELLING Osteopetrosis is a trait that can be inherited in an autosomal dominant, autosomal recessive or X-linked manner, and genetic counselling will depend on the mode of inheritance for particular family and it is must to educate the patient possibilities of future offspring getting affected .

18. SUMMARY Osteopetrosis is disease of osteoclast dyfunction due to gene mutation leading to abnormal bone density and associated conditions like Cranial nerve palsy Recurrent infection Hepato-splenomegaly Loss of differentiation between the medullary and cortical bone “sandwich vertebra” “bone-within-bone” Failure of remodeling- Erlenmeyer flask deformity Pathologic fractures GENETIC COUNSELING IS MUST

19. Thank you