Copyright © 2007 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
Marvin E. Steinberg, MD*,
University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
Posted June 2007
Currently there is a considerable difference of opinion in
the orthopaedic community regarding the management of patients with
osteonecrosis of the femoral head. If left untreated, most osteonecrotic hips
will undergo a progression to femoral head collapse and will require
reconstructive surgery. Our challenge is to diagnose and treat the condition sufficiently
early to halt or retard progression. Unfortunately, there is as yet no
completely satisfactory method to accomplish this1-3.
The authors have attempted to gain insight into this problem
by polling a large number of experienced hip and knee surgeons in the United
States in order to understand their current approach to the evaluation and
treatment of osteonecrosis. Although there are many areas of agreement among
the surgeons, the authors noted that there was considerable variability in the
practice patterns reported. This study provides clinically interesting and useful
information. Importantly, the authors emphasize that they are reporting the current
practice patterns of a number of experienced hip surgeons and are not
attempting to make specific recommendations themselves. I agree with the
majority of their conclusions.
Although the mean annual number of total joint arthroplasties
performed by the respondents was 264, the mean number of surgical interventions
for osteonecrosis was only fourteen. Thus, osteonecrosis is not common and few
individuals have the opportunity to gain substantial experience with it. Therefore,
it is not surprising that there is a considerable diversity of opinion in the
literature and among the respondents about the best way to manage this
disorder.
The responses indicated that the stage of the disease ranked
highest in importance in determining treatment, followed by the category of age
and then pain. In evaluating osteonecrosis, both the type of pathologic change
and the extent of involvement are important. The authors acknowledged that it
was not possible for them to present all possible clinical and/or radiographic scenarios,
and accordingly the questionnaire did not allow the respondents to express
their opinions about the importance of lesion size. In practice, lesion size
must be an integral part of the evaluation because the prognosis and treatment
for a small lesion may differ considerably from that of a moderate-to-large
lesion4,5.
There was general agreement that in earlier, precollapse
stages (I and II), it is usually preferable to pursue some type of intervention
to retard or halt the progression of the disease in symptomatic patients. Core
decompression was the treatment of choice of roughly 70% of respondents for
both the twenty-four-year-old and the forty-eight-year-old hypothetical patients.
Most published studies show core decompression to be superior to nonoperative
care in the treatment of a precollapsed lesion, and the complication rate is
extremely low if the procedure is properly performed2,3,5. However, patients who
were asymptomatic or who had minimal symptoms were most often treated
nonoperatively. Many respondents apparently assumed that the prognosis for the
asymptomatic hip was considerably better than the prognosis for the symptomatic
hip. However, this assumption is not supported by the literature, as pointed
out by the authors, and many reports have shown that the majority of
asymptomatic lesions will progress to symptomatic lesions and eventual collapse3-6. Thus, prophylactic
treatment should not be withheld because of an absence of symptoms, in the hope
that the lesion will heal spontaneously.
There was also a tendency to recommend surgery more often
for stage-II than for stage-I (preradiographic) disease. However, there may be
little difference in prognosis between these stages, with all other factors
being equal3,5,6.
Arthroplasty—usually in the form of a conventional total hip
replacement—was the most commonly recommended procedure for osteonecrosis of
the femoral head when collapse of the femoral head had occurred. For stage IV,
which includes femoral head flattening without acetabular changes, there was
some interest among the respondents in hemiarthroplasty with use of either conventional
femoral endoprostheses or surface replacement hemiarthroplasty. Studies have
shown that the results obtained with unipolar or bipolar hemiarthroplasty are inferior to the results obtained with total
hip replacement and that hemiarthroplasty should therefore rarely be considered3.
Once radiographic changes are apparent in the acetabulum (stages V and VI),
arthroplasty should include both the femoral and the acetabular sides of the
joint2,3. Conventional total hip replacement
was the predominant choice, although a small number preferred surface
replacement arthroplasty in the younger individual.
The older literature suggested that, when compared with
patients who had osteoarthritis, patients with osteonecrosis had substantially
inferior results following total hip replacement2,3; thus, surgeons are still somewhat reluctant to advise younger
patients with osteonecrosis to undergo conventional total hip replacement.
However, studies in which newer components and techniques were employed have shown
considerable improvement in results in patients with osteonecrosis of the
femoral head2,3,7.
Some advocate surface replacement arthroplasty as a more
conservative procedure than conventional total hip replacement. A high failure
rate occurred with the original surface replacement arthroplasty prostheses
that were used in the 1970s, and the procedure was essentially abandoned. In
modern surface replacement arthroplasty, the acetabular component is quite
different; however, the femoral component has changed little, and therefore we
may find that the failure rate on the femoral side has not decreased as much as
we would hope. The short and intermediate-term results seen with surface
replacement arthroplasty and surface replacement hemiarthroplasty are
promising, but we will need greater numbers and longer follow-up to determine
the eventual survivorship of these components in patients with osteonecrosis of
the femoral head1,2,3.
Nonoperative methods of therapy, such as anticoagulation,
lipid-lowering agents, bisphosphonates, ultrasound, and electrical stimulation,
were rarely used by the respondents to the survey. As pointed out by the
authors, these techniques are intriguing, but, at this time, the literature
does not support their routine use. Vascular grafts and osteotomies were chosen
infrequently. Although some have reported excellent results with these
procedures, they are technically quite demanding, have a substantial prevalence
of complications, and have received mixed reports in the literature. They
should be reserved for the patient with special indications and should be
performed only by individuals familiar with these techniques1,2,3.
The authors conclude by emphasizing that the variability of
practice patterns reported underscores the need for further research on
osteonecrosis. This will require controlled, prospective multicenter studies
involving sufficient numbers of patients with various stages of osteonecrosis
and an adequate follow-up time. Once the results of these studies become
available, they will enable us to determine more accurately the best methods
for managing patients with osteonecrosis.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the author, or a member of his immediate family, is affiliated or associated.
References
1. Lieberman JR, Berry DJ, Mont MA, Aaron RK, Callaghan JJ, Rajadhyaksha AD, Urbaniak JR. Osteonecrosis of the hip: management in the 21st century. Instr Course Lect. 2003;52:337-55.
2. Mont MA, Bezwada HP. Osteonecrosis: strategies for treatment. In: Callaghan JJ, Rosenberg AG, Rubash HE, editors. The adult hip. 2nd ed. Philadelphia: Lippincott, Williams and Wilkins; 2007. p 477-99.
3. Steinberg ME, Mont MA. Osteonecrosis. In: Chapman MW, editor. Chapman's Orthopaedic Surgery. 3rd ed. Philadelphia: Lippincott Williams and Wilkins; 2001. p 3263-308.
4. Hungerford DS, Jones LC. Asymptomatic osteonecrosis: should it be treated? Clin Orthop Relat Res. 2004;429:124-30.
5. Steinberg ME, Larcom PG, Strafford B, Hosick WB, Corces A, Bands RE, Hartman KE. Core decompression with bone grafting for osteonecrosis of the femoral head. Clin Orthop Relat Res. 2001;386:71-8.
6. Hernigou P, Poignard A, Nogier A, Manicom O. Fate of very small asymptomatic stage-I osteonecrotic lesions of the hip. J Bone Joint Surg Am. 2004;86:2589-93.
7. Kim YH, Oh SH, Kim JS, Koo KH. Contemporary total hip arthroplasty with and without cement in patients with osteonecrosis of the femoral head. J Bone Joint Surg Am. 2003;85:675-81.
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