- See:
Co-authored by Edward Harvey M.D.
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AVN following Femoral Neck Fracture:
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AVN following IM Nailing:
- Discussion:
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pathogenesis and risk factors:
- references:
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Fat-cell changes as a mechanism of avascular necrosis of the femoral head in cortisone-treated rabbits.
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Intravascular coagulation and osteonecrosis.
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natural history
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blood supply to femoral head:
- diff dx:
- synovitis;
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transient osteoporosis
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femoral neck stress frx:
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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 MD 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 P. Bizot et al (CORR No 357 1998. p 127), 35 patients w/ bilateral AVN following bone marrow transplant were followed;
- of these 70 hips, 56 hips went on to collapse;
- references:
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Prediction of Collapse with Magnetic Resonance Imaging of Avascular Necrosis of the Femoral Head.
- Prognosis of early stage avascular necrosis of the femoral head. H. Ito MD et al. CORR No 358 p 149-157.
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Natural history of nontraumatic avascular necrosis of the femoral head.
- Femoral head osteonecrosis after bone marrow transplantation. P. Bizot MD.
CORR. No 357. 1998. p 127-134.
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Osteonecrosis of the Femoral Head After Solid Organ Transplantation.
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Asymptomatic Osteonecrosis: Should It Be Treated?
- Radiographic Studies:
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x-rays:
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ficat classification
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enneking's stages of osteonecrosis
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bone-scanning:
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magnetic resonance imaging:
- preferred method for dx of radiographically occult AVN, since its more sensitive than Bone Scans or plain films;
- note that there is a high incidence of bilateral AVN, and that MRI may pick up AVN in the contralateral asymptomatic hip;
- Treatment: Stages I, II, and III:
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medications:
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anticoagulation agents:
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Enoxaparin Prevents Progression of Stages I and II Osteonecrosis of the Hip.
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bisphosphonates:
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fosamax: this medication may interfere with
resorption of necrotic bone, which may delay subchondral collapse and progression of arthrosis;
- reference:
The Use of Alendronate to Prevent Early Collapse of the Femoral Head in Patients with Nontraumatic Osteonecrosis.
- electromagnetic fields:
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core decompression:
- bone grafting should probably be a part of every core decompression procedure;
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free vascularized fibular grafting:
- references:
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Fate of Very Small Asymptomatic Stage-I Osteonecrotic Lesions of the Hip.
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Spontaneous Resolution of Osteonecrosis of the Femoral Head.
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Capacitive coupling as an adjunctive treatment for avascular necrosis.
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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 inaddition 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 (range, four to fourteen years) postoperatively, sixteen (62 percent) of the 26 hips with stage-III disease had a
good or excellent Harris hip score;
- the majority of these patients underwent this procedure using a modified anterolateral approach, inorder to preserve the remaining
posterior
blood supply to the femoral head;
- references:
- Precision fit surface hemiarthroplasty for femoral head osteonecrosis: long term results.
Amstutz. JBJS Vol 76-B. 1994. p 423-427.
- Surface Replacement Hemiarthroplasty for the Treatment of Osteonecrosis of the Femoral Head. Hungerford, MW.
JBJS 80-A: 1656-64, 1998
- 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:
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Bipolar versus total hip arthroplasty for avascular necrosis of the femoral head. A comparison.
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Clinical and motion studies of the Bateman bipolar prosthesis in osteonecrosis of the hip.
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Bipolar prosthetic replacement for the treatment of avascular necrosis of the femoral head.
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Bipolar versus total hip arthroplasty for hip osteonecrosis in the same patient.
- arthrodesis:
- arthrodesis of the hip has been used in some series, but becuase 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.
Avascular necrosis complicating fracture of the distal tibial epiphysis.
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.
Osteonecrosis after renal transplantation in children.
Multimodality approach to osteonecrosis of the femoral head.
Osteonecrosis of the femoral head. A prospect
Osteonecrosis after renal transplantation in children.
Osteonecrosis in the transplant recipient.
Deformities of the hip in adults who have sickle-cell disease and had avascular necrosis in childhood. A natural history of fifty-two patients.
Long term followup of thorough debridement and cancellous bone grafting of the femoral head for avascular necrosis.
Avascular necrosis of bone after cardiac transplantation. Prevalence and relationship to administration and dosage of steroids.
Current Concepts Review. Non-Traumatic Avascular Necrosis of the Femoral Head.
