This issue of The Journal contains two important
articles related to the topic of routine pathological examination
of operative specimens from patients undergoing total hip or total
knee arthroplasty for the treatment of osteoarthritis. As pointed
out in the article by Kocher et al., many surgeons believe that
routine pathological examination of specimens removed at surgery is
mandatory4. However, regulations
by the Joint Commission on Accreditation of Healthcare Organizations
note that the clinical staff, in consultation with the pathologist,
may make an exception to mandatory submission of tissue when certain
conditions are met3. These conditions
include (1) the quality of care is not compromised by the exemption,
(2) another suitable means of verification of removal has been used,
and (3) there is an authenticated operative note or other official
report that documents tissue removal.
Kocher et al. analyzed a total of 1234 specimens removed at the
time of total hip or total knee arthroplasty for the treatment of
osteoarthritis4. In each case,
the preoperative clinical diagnosis was compared with the final
pathological diagnosis obtained after histological evaluation of
the resected tissue. The authors used three categories for their
comparison: (1) concordant
(agreement between the clinical and pathological diagnoses), (2) discrepant
(a difference between the clinical and pathological diagnosis but
no alteration in patient management), and (3) discordant (a difference
between the clinical and pathological diagnoses resulting in alteration
of patient management).
The authors found a concordance rate of 97.6 percent. There was
a 2.3 percent rate of discrepant diagnoses, which included rheumatoid
arthritis, osteonecrosis, pseudogout, pigmented villonodular synovitis,
hemochromatosis, hypercellular bone marrow, and gout. The cost to
the laboratory per discrepant diagnosis was $4383. Apparently the
care of these patients, including those with unexpected osteonecrosis
of the femoral head, was not altered by the histological diagnosis.
Only one discordant diagnosis (0.1 percent), a case of unexpected
and unexplained granulomatous inflammation, was identified. The
calculated cost per discordant diagnosis was $122,728. The authors concluded
that routine pathological (histological) examination of surgical
specimens obtained at primary total hip or total knee arthroplasty
may not be justified for patients with the preoperative diagnosis
of osteoarthritis since the prevalence of findings that altered
patient management in their hospital was so low. On the other hand,
they recommended routine histological evaluation of specimens from
patients with the preoperative diagnosis of osteonecrosis or inflammatory
arthritis.
In a related article, Billings et al. reported the recognition
of sarcoma in two routinely evaluated specimens that had been retrieved
during primary total hip arthroplasty1.
One of the two patients had undergone radiation and chemotherapy
for cervical carcinoma. The other patient reported increasing pain
and disability associated with Paget disease. Billings et al. emphasized
the importance of routine pathological examination of femoral head
specimens retrieved during total hip arthroplasty, especially when
a patient is at risk for the development of a secondary malignant
tumor.
Critical to the calculations described by Kocher et al.4 are the absence of rare diseases
in their cohort of 1234 cases and the values used for cost calculation.
The routine histological evaluation of specimens obtained at primary
arthroplasty in patients with osteoarthritis by one of us (T. B.)
yielded rare cases of Paget disease, infection, enchondroma, Gaucher
disease, multicentric reticulohistiocytosis, lymphoproliferative
disorders, metabolic bone disease (including osteomalacia), crystalline
arthropathies, oxalosis, and inflammatory arthropathies other than
rheumatoid arthritis. Some of these systemic disorders had been
recognized preoperatively, but documention of involvement of the
femoral head influenced the care of some patients. Although these
cases are rare, some of the diagnoses were important to the individual
patients involved.
There are several ways to improve the cost efficiency of tissue
evaluation. One way is to reduce the proportion of specimens submitted
to the pathology laboratory when a discordant diagnosis is unlikely;
another is for the pathology laboratory to reduce costs (and presumably
charges). Interestingly, in the series reported by Kocher et al.,
overall laboratory costs exceeded reimbursement4.
It should be noted, however, that the costs, charges, and reimbursement
values used in the calculations by Kocher et al. might be unique
to their hospital environment. The values quoted for charges, for
example, are nearly twice the fees charged at the Cleveland Clinic
for similar tests. In order to reduce costs, Kocher et al. recommend
not routinely submitting tissue obtained at primary total joint
arthroplasty for the treatment of osteoarthritis. However, there
may be other options that could limit the potential harm of missing
important diagnoses. One such option is to routinely send such tissue
to the pathology laboratory but for the pathologist to submit tissue
for histological examination only if requested by the surgeon or
if gross evaluation of the tissue suggests an unexpected finding.
This gives the pathologist the opportunity to look at the synovial
tissue and to inspect the cut surface of the femoral head for evidence
of osteonecrosis or other abnormality. A charge for a gross diagnosis
is made, but it should be substantially less than that for histological
evaluation. If gross evaluation reveals an unexpected finding, then
representative tissue can be submitted for histological evaluation.
It also seems appropriate to perform routine histological evaluation
of specimens from patients with osteonecrosis, inflammatory arthropathies,
or femoral neck fracture and of specimens obtained at revision arthroplasty.
While reducing costs is an important concern, one should be mindful
that the histological study of resected tissue serves many purposes
in addition to immediate patient care. As noted by Kocher et al., histological
diagnoses also facilitate diagnostic quality assurance and provide
insight into the pathogenesis and natural history of disease4. In a previous, related editorial
in The Journal, Bullough and Dorfman pointed out that examination
of tissue by a trained independent physician is the gold standard
of quality assurance2. Furthermore,
much of our current understanding about degenerative joint disease,
osteonecrosis, and inflammatory arthropathies has been derived from
careful but routine evaluation of specimens obtained during total
joint replacement. They cautioned that such specimens should not
be discarded in a cursory manner2.
The value of this process to research and education should not be
overlooked. Nevertheless, the take-home message for the practicing
orthopaedic surgeon is that the routine histological evaluation of
tissue excised from patients with an uncomplicated case of osteoarthritis
may not be necessary at all hospitals. On the other hand, when a
patient has another disorder that might complicate osteoarthritis,
when careful gross examination of synovial tissue or a sectioned
femoral head suggests an unexpected finding, or when the results
of such analysis are used for ongoing quality-assurance studies,
histological examination is warranted.
Charles R. Clark, M.D.Department of Orthopaedic Surgery
University of Iowa
Iowa City, Iowa
Thomas Bauer, M.D., Ph.D.Department of Pathology
Cleveland Clinic Foundation
Cleveland, Ohio