Copyright © 2008 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
Raj D. Rao, MD*,
Department of Orthopaedic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin
Posted July 2008
Lau et al. report important data on mortality following
vertebral compression fractures in patients who were sixty five years or older
at the time of diagnosis. With use of random samples of Medicare data, the
authors determined mortality rates following an index diagnosis of vertebral
compression fracture. Mortality rates were compared with those of a cohort
selected from the same database by attempting to match each patient in the compression
fracture cohort with five control patients whose ages were within three years
of the age of the "case" patient. The authors also studied the role of medical
or surgical comorbidity in contributing to mortality in both groups.
Osteoporotic vertebral compression fractures are a
frequently encountered clinical problem in the elderly population. In most
patients, these fractures cause little long-term morbidity other than decreased
height and an increase in forward stooped posture. However, a subset of
patients diagnosed with these fractures will have intractable or severe pain
requiring treatment such as medications, brace wear, percutaneous
methylmethacrylate augmentation of the fracture, or surgical decompression and
stabilization1. Increased patient and physician awareness of the fracture
and its treatment options, as well as the relative ease with which percutaneous
augmentation of the vertebral body can be carried out, have likely contributed
to an increase in treatment for these fractures over the past few years.
The results reported by Lau et al. need to be viewed in this
context. While the authors have shown an association between vertebral
compression fractures and mortality, a true causal relationship has not been
established.
In addition, certain limitations of the study with regard to
data collection and interpretation limit the conclusions that can be drawn:
Patients with International Classification of Diseases,
Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes of 733.13,
805.0, 805.2, 805.4, 805.6, or 805.8 were selected for analysis. These
diagnosis codes include patients in whom metastatic disease has caused
pathologic fracture of the vertebral bodies. One must assume that patients with
metastatic disease would have higher rate of mortality than an age-matched
population would.
The authors have interpreted the absence of earlier claims
with these codes to denote a new diagnosis of a symptomatic fracture. Many of
these codes will have been entered by a hospital billing specialist poring over
radiology reports and hospital charts in an attempt to accurately identify all
diagnoses during that hospitalization. The presence of a code on a Medicare
claim does not necessarily indicate that the fracture was the primary diagnosis
or exclude concurrent severe or more symptomatic pathology.
The authors have attempted to match the two cohorts by age.
Despite the best efforts of the authors, the compression fracture cohort had a
lower percentage of patients in the younger age groups and a much higher
percentage of patients who were ≥85
years of age (see Table I in Lau et al.). This could account for some of the higher mortality
seen in this group.
The authors have attempted to stratify the comorbidity in
the two cohorts. The compression fracture cohort again has a higher percentage
of patients with greater degrees of comorbidity, potentially contributing to higher
mortality rates (see Table I).
The data do not address the role of treatment in patients
with vertebral compression fracture. Future studies will hopefully allow us to
assess whether our current treatment options are improving quality of life over
the long term or reducing mortality rates. Given that this study was carried
out between 1997 and 2004, it is very likely that a number of these patients
were treated with percutaneous augmentation of the fracture with use of
methylmethacrylate. The authors' data raise the intriguing and troubling
question of whether some of our current treatment options for patients with
these fractures are a factor contributing to higher mortality rates in the long
term.
The authors have appropriately stated that vertebral
compression fractures are rarely a direct cause of death. More likely than not,
vertebral compression fractures that occur with minimal or no trauma serve as a
marker of poor health and help to identify more vulnerable patients who may
benefit from a comprehensive medical approach to their often multiple problems.
*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.
Reference
1. Rao RD, Singrakhia MD. Painful osteoporotic vertebral fracture: pathogenesis, evaluation, and roles of vertebroplasty and kyphoplasty in its management. J Bone Joint Surg Am. 2003;85:2010-22.
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