In 1877 James Paget was the first to describe the disease. Femoral head
osteonecrosis is a common disease entity with approximately 20,000 new cases
reported each year. Osteonecrosis is the underline disease in as many as 10% of
500,000 total hip replacements performed every year in the United States. The
most of these total hip arthroplasties are done in individuals in their late 30s and
early 40s. The causes of osteonecrosis include interruption of the vascular supply
as result of local trauma or non-traumatic systemic conditions. Understanding of
pathogenesis and pathophysiology of non-traumatic osteonecrosis is still obscure.
Nevertheless, environmental and genetic factors have been implicated in the
pathogenesis of non-traumatic osteonecrosis. These include corticosteroid
administration, alcohol consumption, smoking, hyperlipidaemia, autoimmune diseases
and a wide variety of conditions accompanied by increased tendency for
intravascular coagulation and dysfunction of bone microvascular circulation.
Aim of the study:
This study considered the femoral head osteonecrosis a systemic disease and tried
to answer to the following questions:
1. How the existing classification systems could become more effective and
2. How the basic diseases in the secondary osteonecrosis affect the outcomes?
3. Which is the incidence and which is the pathogenesis of the multiple
symptomatic osteonecrosis lesions in the skeleton?
4. Which is the potential association of femoral head osteonecrosis with
genetic mutation leading to coagulation disorders?
5. If dysfunction of microvascular system is critical for the development of
osteonecrosis then, this dysfunction will possibly also affect the rest of
microvascular systems of the body (brain, eyes, heart).
6. What is the outcome after the different methods of treatment and which is
the functional status of the hip joint according to the patients.
Between 2000 and 2005,180 patients with femoral head osteonecrosis were
studied. The diagnosis of the disease was based on imaging studies with plain x-rays
and magnetic resonance imaging (MRI). Staging of osteonecrosis severity was
performed according to ARCO classification system. Imaging studies with x-rays
and fast sequence of MRI were also performed at every location of the skeleton
where the patient referred deep osteal pain.
As osteonecrosis was considered a systemic disease, a basic stage of this
study was the detailed medical as well as individual and hereditary history (history of steroids treatment, smoking status, alcohol consumption, coagulation disorders
etc). The primary disease, in cases of secondary osteonecrosis, was classified
according the criteria of the American Anesthesiology Association (ASA).
Then, with a blood specimen was performed laboratory testing blood cell
count and complete blood chemistry as well as for genetic mutation leading to
After that an investigation for dysfunction of microvascular system was
performed (brain MRI, heart echo, carotid tripex and fundanoscopy). After the
preliminary findings of brain MRI, the Minnesota Multiphase Personality Inventory
was used to investigate personality disorder in patients with non traumatic
Finally, Harris Hip Score (HSS), Oxford Hip Score and Hospital for Special
Surgery Hip Rating System (HSS) were used for the evaluation of the outcome
after the treatment with core decompression, free vascularized fibula graft,
porous tantalum implant and total hip replacement.
The use of MR images findings in any classification system could
considerably improve the accuracy and prognostic value of stage diagnosis for an
osteonecrotic lesion. So, it is possible to achieve a better choice of treatment and a
better follow up of a patient with hip osteonecrosis.
The severity of the secondary osteonecrosis during the reference to an
orthopaedic department for diagnosis and/or treatment is correlated with the
severity of primary disease According to ASA classif ication.
The sensitivity and the negative predictive value for the x-rays in diagnosis
of symptomatic multiple osteonecrotic lesions were very low (62.5% and 8.06%
respectively). Osteonecrosis with multiple symptomatic lesions is correlated with
total number of risk factors and with the smoking, while a tendency for correlation
is presented for the alcohol consumption.
The most of the patients (70.5%) with non traumatic osteonecrosis were
presented with at least one genetic mutation leading to coagulation disorders.
The factor V Leiden and the mutation AG/AG of the factor II seem to be
the most important at correlation of osteonecrosis with the mutations leading to
The population with non traumatic osteonecrosis presented an incidence of
56.6% for cerebral white matter lesions at brain MRI.
Patients with 192QQ genotype showed an increased risk for femoral head
osteonecrosis and. Carriers of the PON1 192Q allele constitute possible candidate
for osteonecrosis and cerebral white matter lesions susceptibility. They also may
have an inherited defect in detoxif ication of environmental toxins.
The patients with non traumatic osteonecrosis presented high incidence
(44.4%) of depression according to the MMPI, which is correlated with the
cerebral white matter lesions.
The patients who were treated with free vascularized fibula graft
presented the better outcomes in comparison with the others joint preserving methods of treatment
Osteonecrosis has been associated with a wide range of conditions. Because
osteonecrosis may affect patients with a variety of risk factors, it is important
that caregivers have a heightened index of suspicion. Early detection may affect
prognosis because prognosis is dependent on the stage and location of the disease.
In particular, the disease should be suspected in patients with a history of steroid
usage, especially in conjunction with other illnesses that predispose the patient to
osteonecrosis. Osteonecrosis has to be considered a systemic disease and patients
with osteonecrosis have to undergo to a holistic investigation of the
muskeloskeletal system and the others systems that may be affected from the
dysfunction of the small vessels.||en