- pathogenesis - vascular interruption
- blood supply to femoral head
- specific inciting causes
- natural history
- diff dx:
- transient osteoporosis
- femoral neck stress frx
- metastatic disease
- trochanteric bursitis:
- ref: Avascular necrosis of the femoral head presenting as trochanteric bursitis
- 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;
- 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:
- ficat classification
- In Brief: Ficat Classification: Avascular Necrosis of the Femoral Head
- enneking's stages of osteonecrosis
- 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:
- anticoagulation agents:
- Enoxaparin Prevents Progression of Stages I and II Osteonecrosis of the Hip.
: 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:
- 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
- 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:
- 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 of the hip has been used in some series, but because of 50-80 % prevalence of bilaterality of AVN, this may be poor choice
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.