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Duke Orthopaedics
presents
Wheeless' Textbook of Orthopaedics

Avascular Necrosis of Femoral Head


- Discussion:
    - pathogenesis - vascular interruption
           - blood supply to femoral head 
    - specific inciting causes
    - natural history 
    - diff dx:
           - synovitis;
           - transient osteoporosis
           - femoral neck stress frx 
           - metastatic disease 
           - trochanteric bursitis:
                 - ref: Avascular necrosis of the femoral head presenting as trochanteric bursitis.
    - prognosis:
           - in general, patients with confirmed AVN have a 70-80% chance of collapse after 3 years;
           - in the series of 72 hips (general population) w/ MRI changes c/w AVN (followed by Ito H, et al (1999)), 64% became symptomatic;
           - necrotic lesions greater than 2/3 of the wt bearing portion of the femoral head on T1 central coronal images;
                 - of these hips 75% became symptomatic, where as 25% remain asymptomatic after 6 years;
           - in the study by Bizot P, et al (1998), 35 patients w/ bilateral AVN following bone marrow transplant were followed;
                 - of these 70 hips, 56 hips went on to collapse;
           - references:
                 - Prediction of Collapse with Magnetic Resonance Imaging of Avascular Necrosis of the Femoral Head.
                 - Prognosis of early stage avascular necrosis of the femoral head.  
                 - Natural history of nontraumatic avascular necrosis of the femoral head.
                 - Femoral head osteonecrosis after bone marrow transplantation.  
                 - Osteonecrosis of the Femoral Head After Solid Organ Transplantation.
                 - Asymptomatic Osteonecrosis: Should It Be Treated? 


 - Radiographic Studies:
    - x-rays:
           - ficat classification 
                  - In Brief: Ficat Classification: Avascular Necrosis of the Femoral Head 
           - enneking's stages of osteonecrosis
    - bone-scanning:
    - magnetic resonance imaging:
           - preferred method for dx of  occult AVN, since its more sensitive than bone scan or plain films;
           - note high incidence of bilateral AVN, and that MRI may pick up AVN in opposite asymptomatic hip; 

               


- Treatment: Stages I, II, and III:
      - medications:
              - anticoagulation agents:
                      - Enoxaparin Prevents Progression of Stages I and II Osteonecrosis of the Hip.
              - bisphosphonates:
                      - fosamax: this medication may interfere with resorption of necrotic bone, which may delay subchondral collapse and progression of arthrosis;
                      - ref: The Use of Alendronate to Prevent Early Collapse of the Femoral Head in Patients with Nontraumatic Osteonecrosis.
      - electromagnetic fields:
      -
core decompression: 

      - free vascularized fibular grafting:
              - references:
                     - Fate of Very Small Asymptomatic Stage-I Osteonecrotic Lesions of the Hip. 
                     - Spontaneous Resolution of Osteonecrosis of the Femoral Head.
                     - Capacitive coupling as an adjunctive treatment for avascular necrosis
                     - Effects of pulsed electromagnetic fields on Steinberg ratings of femoral head osteonecrosis

- Treatment: Stages III, IV and V:
      - resurfacing arthroplasty:
            - indicated for later stages of disease in addition to disease which involves a large portion of the femoral head;
            - has had only intermittent success in the past, but w/ modern components there has been renewed interest;
            - it is possible that resurfacing arthroplasty will emerge as the procedure of choice for AVN;
            - note that a mismatch between the size of the prosthesis and the acetabulum may contribute to unfavorable restults;
                   - it is probably important that sizes be available in at least 2 mm increments;
            - in the study by Hungerford, et al (1998), 33 femoral resurfacing procedures in 25 patients who had stage-III or IV osteonecrosis of femoral head;
                   - 30 hip prostheses (91 percent) survived for a minimum of five years;
                   - at a mean of 10.5 years (4-14 years) postop, 16 (62 %) of the 26 hips with stage-III disease had a good or excellent Harris hip score;
                   - majority underwent this procedure using a modified anterolateral approach, to preserve the remaining posterior blood supply to the femoral head;
            - references:
                   - Precision fit surface hemiarthroplasty for femoral head osteonecrosis: long term results.   
                   - Surface Replacement Hemiarthroplasty for the Treatment of Osteonecrosis of the Femoral Head.  
                   - Is bipolar hemiarthroplasty a reliable option for Ficat stage III osteonecrosis of the femoral head? 15- to 24-year follow-up study 
      - total hip arthroplasty:
            - ongoing concern over cement disease, particulate matter, and stress shielding changes in the femur in cemented or non-cemented prostheses makes a total hip arthroplasty a less desirable option;
      - bipolar arthroplasty:
            - references:
                   - Bipolar versus total hip arthroplasty for avascular necrosis of the femoral head. A comparison.
                   - Clinical and motion studies of the Bateman bipolar prosthesis in osteonecrosis of the hip.
                   - Bipolar prosthetic replacement for the treatment of avascular necrosis of the femoral head.
                   - Bipolar versus total hip arthroplasty for hip osteonecrosis in the same patient. 
                   - Acetabular diameter measurement determines proper prosthetic head size in hemiarthroplasty for femoral head osteonecrosis.
      - arthrodesis:
            - arthrodesis of the hip has been used in some series, but because of 50-80 % prevalence of bilaterality of AVN, this may be poor choice 


References

Current Concepts: Nontraumatic Necrosis of Bone (Osteonecrosis).

Recent Advances in Great Britain--Symposium: Caisson Disease of Bone.

Bicentenary Festschrift: Segmental Vascular Changes in the Femoral Head in Children and Adults.

Bilateral non-traumatic aseptic osteonecrosis in the femoral head. An experimental study of incidence.

Multimodality approach to osteonecrosis of the femoral head.

Osteonecrosis of the femoral head. A prospective randomized treatment protocol.

Degeneration of the acetabular cartilage in osteonecrosis of the femoral head: histopathologic examination of 15 hips

Histologic analysis of acetabular and proximal femoral bone in patients with osteonecrosis of the femoral head.

Precision-fit surface hemiarthroplasty for femoral head osteonecrosis. Long-term results

Avascular Necrosis of the Femoral Head in Children With Acute Lymphoblastic Leukemia: A 4- to 9-year Follow-up Study



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, January 2, 2013 12:28 pm