avascular necrosis


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Avascular Necrosis (AVN): 

Avascular Necrosis (AVN) October 12, 2011 Krystal Fosmire Sandra Kappes David Terry

Avascular Necrosis Description: 

Avascular Necrosis Description Necrosis of the vascular supply of the femoral head Causes necrosis of bone and marrow in the femoral head Subsequent femoral head collapse is likely Most often found at the femoral neck s/p fracture 1 Image from Aiello, 2011 1

AVN Other Causative Factors: 

AVN Other Causative Factors Steroids Aspirin Collagen Vascular Disease Alcoholism Renal Disease 2 Cortisone Medications Sickle Cell Disease Pancreatitis Systemic Lupus Erythematosus 3

AVN Signs and Symptoms: 

AVN Signs and Symptoms In some instances, it remains painless Most cases- pain with use With AVN of hip, pain with rotation may be felt in the groin May experience onset of pain with weight bearing, and subsequent relief upon rest 3

Stages of AVN2: 

Stages of AVN 2 0. Incidental finding – no symptoms 1. Pain in the proximal thigh and limited motion 2. Symptoms worse. Radiographs show sclerosis and/or cystic changes. 3. Crescent-shaped subchondral fracture line appears, followed by subchondral collapse 4. Radiographic evidence of osteoarthritis

AVN Prognosis: 

AVN Prognosis Patients with confirmed AVN have 70-80% chance of collapse after 3 years 4 Of patients with necrotic damage 2/3 of weight bearing surface (from T1 images): 75% become symptomatic 25% lack symptoms after six years 4 Bilateral AVN subsequent to marrow replacement: 56/70 went on to collapse 4

Best Imaging in early stages – MRI5: 

Best Imaging in early stages – MRI 5 Detects chemical changes in the bone marrow Allows visualization of affected area (CT to determine extent of damage Bone rebuilding process can be assessed May show diseased areas that are not yet symptomatic

Best Imaging in later stages – plain film radiographs5: 

Best Imaging in later stages – plain film radiographs 5 Visualization of calcification Visualization of new bone formation Visualization of micro fractures

Biomechanical Effects of Osteonecrosis6: 

Biomechanical Effects of Osteonecrosis 6 Inadequate nutrition to the femoral head causes bone death Bone death leads to changes in the normal articulation between the femoral head and the acetabulum causing abnormal motion Bone death and abnormal articulation leads to destruction of articular cartilage causes disabling arthritis If left untreated, the femoral head collapses

Physical Impairments7: 

Physical Impairments 7 Pain with hip movement Complaints of throbbing or aching in the groin or buttock Joint stiffness Limited PROM, especially forced IR and abduction Difficulty with weight bearing activities


Radiograph 8 Stage 4 AVN noted on this radiograph with the signs of osteoarthritis No joint space remaining Spurring of the greater trochanter Increased radiodensity at the femoral acetabular joint

Magnetic Resonance Imaging8: 

Magnetic Resonance Imaging 8 No joint space remaining Spurring of the greater trochanter Increased radiodensity at the femoral acetabular joint Bony edema noted.

Class Question:: 

Class Question: This technique is used to prevent collapse of the femoral head. 9 What is the technique and why does it prevent collapse of the femoral head in patients with osteonecrosis ?

Class Question 2:: 

Class Question 2: Describe interventions that would be appropriate for each stage of AVN. Are there stages that PT would not be used?

Works Cited: 

Works Cited 1 Aiello , M. (2011, May 25). Imaging in avascular necrosis of the femoral head . Retrieved from http:// emedicine.medscape.com/article/386808-overview 2 Agustsson , H. (2011). Imaging course note packet ( pht 6403e) . University of St. Augustine, St. Augustine, FL . 3 Shiel , W. (2006, September 25). Aseptic necrosis . Retrieved from http:// www.medicinenet.com/aseptic_necrosis/article.htm 4 Wheeless , C. (2011, May 13). AVN of the femoral head . Retrieved from http:// www.wheelessonline.com/ortho/avn_following_femoral_neck_fracture 5 Imhof , H., Breitenseher , M., Trattnig , S., Kramer, J., & Hoffman, S. (1997). Imaging of avascular necrosis of bone. Eur Radiol . , 7 (2), 180-6. 6 The National Osteonecrosis Foundation and The Center for Osteonecrosis Research and Education.  (10 October 2011). Osteonecrosis Introduction. Retrieved from http://nonf.org/nofbrochure/nonf-brochure.htm.

Works Cited (Continued): 

Works Cited (Continued) 7 Kelly, J., Medscape Reference.  (10 October 2011). Femoral Head Avascular Necrosis Clinical Presentation. Retrieved from http://emedicine.medscape.com/article/86568-clinical . 8 Government of Western Australia Department of Health. (2011, October 12). Avascular necrosis of the hip . Retrieved from http://www.imagingpathways.health.wa.gov.au/includes/dipmenu/avas_nec/image.html 9 American Academy of Orthopaedic Surgeons. (2011, September 01). Osteonecrosis of the hip . Retrieved from http://orthoinfo.aaos.org/topic.cfm?topic=A00216&return_link=0