Unsuspected Malignancies in Routine Femoral Head Histopathologic Examination During Primary Total Hip Arthroplasty: Cost-Effectiveness Analysis

Diagnosis of Waldenstrom Macroglobulinemia Using Postoperative Histopathology During Routine Total Knee Arthroplasty: A Case Report

CASE

We present a 63-year-old patient diagnosed with Waldenstrom macroglobulinemia (WM) through histopathology of bone tissue after total knee arthroplasty for routine osteoarthritis. The patient, surgical team, and the pathologist were unaware of this diagnosis before the surgery.

CONCLUSION

The cost-effectiveness of routine histopathologic examination of bone cuts and synovial samples after total joint arthroplasty continues to be a source of debate. Our case highlights an example of the utility of histopathology because it led to the early detection of WM, resulting in prompt treatment to improve quality of life.

Routine Histopathologic Examination of Bone Obtained During Elective Primary Total Knee Arthroplasty May Not Be Necessary

Background

Many institutions require the routine collection of pathology samples from every primary total knee arthroplasty (TKA) performed. These policies are controversial, and their cost-effectiveness is difficult to define. We sought to judge the cost-effectiveness of one such policy according to World Health Organization recommendations.

Methods

We analyzed 3200 consecutive primary TKAs, comparing our presumed preoperative diagnoses against the diagnoses made by the pathologist. Diagnoses were categorized as concordant (matching), discrepant (not matching but without impact to patient management), or discordant (not matching and resulting in a direct change to patient management). An incremental cost-utility ratio analysis was performed to determine the cost-effectiveness of our institution's policy to routinely collect pathology samples from every primary TKA performed. Cost-effectiveness was defined by World Health Organization guidelines as a cost of less than $228,090 per quality-adjusted life year gained.

Results

Twelve pathology samples were lost before reaching a pathologist. From the remaining 3188 samples, we identified 3158 concordant cases, 29 discrepant diagnoses, and 1 discordant diagnosis. It cost an estimated $10,522.60 to identify each discrepant diagnosis and an estimated $305,155.36 to diagnose one discordant case in our cohort. Our incremental cost-utility ratio analysis revealed that we spent $305,155.36 to gain 0 quality-adjusted life years for our patients.

Conclusions

Routine histopathologic analysis of TKA samples was cost-ineffective in our patient cohort and may not be necessary during routine TKA.

Routine Pathologic Examination of the Femoral Head in Total Hip Arthroplasty: A Survey Study of the American Association of Hip and Knee Surgeons

Background

Current literature does not provide conclusive evidence on whether routine pathologic examination of femoral heads from total hip arthroplasty is indicated or cost-effective. As a result, there is substantial variation in opinion among surgeons related to this issue. Our study aim was to determine factors that impact surgeon propensity to order pathologic examination of femoral heads.

Methods

A 12-question survey was created to evaluate surgeon practices, indications, and patient care implications surrounding routine pathologic examination of femoral heads. The email survey was distributed to all members of the American Association of Hip and Knee Surgeons (n = 2598).

Results

There were 572 survey respondents. Out of all respondents, 28.4% always send femoral heads to pathology, and 27.6% reported an institutional requirement to do so. Of the 572 surgeons, 73.6% report femoral head pathology has never resulted in a change in patient disease course. Factors that increase the likelihood of surgeons ordering femoral head pathologic examination include institutional requirements, medicolegal concern, and prior experience with femoral head pathologic examination changing patients' disease course (P < .001). Cost concern decreases the likelihood of surgeons ordering femoral head pathologic examination (P = .0012).

Conclusions

A minority of surgeons routinely send femoral heads from total hip arthroplasty for pathologic examination, mostly because of institutional requirement. The majority of surgeons feel that femoral head pathologic examination never changes patient management, although others have infrequently detected malignancy and infection. Institutional policy, concern for litigation, and prior experience with discordant pathologic diagnoses increase femoral head pathologic examinations, while cost concern decreases them.

Routine Histopathologic Analysis of Hip and Knee Bone Specimens After Total Joint Arthroplasty

Total hip and total knee arthroplasties (THA/TKA) are some of the most common elective surgeries done in the United States. Routine histopathologic analysis of hip and knee bone specimens after total joint arthroplasty commonly occurs to identify unexpected pathologic findings and serves as a quality assurance measure. As the most common indication for THA and TKA is osteoarthritis, the practice of routine histopathologic analysis may not be routinely warranted. There is no clear consensus on the cost-effectiveness of this practice, and the literature has questioned both the clinical relevance of discrepancies between surgeon diagnosis and histopathological diagnosis and raised concerns about variance in the histological evaluation of resected specimens by pathologists. Femoral head analysis in the setting of femoral neck fractures has been previously reported, yet there is no clear overview for this topic in the setting of elective THA. The histopathologic features of bone specimens during routine total joint arthroplasty, the cost-effectiveness, and current recommendations will be reviewed.

Diagnosis of Prostate Adenocarcinoma on Routine Pathology After a Primary Total Hip Arthroplasty

We present a 67-year-old male patient who presented with insidious worsening of right hip pain over a 6-month period with clinical and radiographic evidence of severe osteoarthritis. The patient underwent a primary total hip arthroplasty where the femoral head specimen was sent to pathology as a routine specimen. Pathology results demonstrated metastatic adenocarcinoma of prostate origin. The present case emphasizes the importance of routine pathologic examination of femoral head specimens retrieved during total hip arthroplasty, particularly since this was a clinically unsuspected finding. Although cases like these are rare and the process of routine pathologic examination raises a concern for economic implications, a timely diagnosis of adenocarcinoma provides benefits for the patient, for which cost-benefit ratios are difficult to quantify.

Routine Pathologic Examination of Femoral Head Specimens from Total Hip Arthroplasty May Not Be Indicated or Cost-effective: A Systematic Review

Background

There is considerable disparity in institutional practices surrounding routine pathologic examination of femoral heads removed during total hip arthroplasty (THA). Multiple groups have studied the merits of routine femoral head pathology in THA, without clear consensus. We sought to further investigate the existing evidence on routine pathologic examination of femoral heads retrieved during THA to determine if this practice provides additional clinical value and is cost-effective.

Material and methods

To conduct a systematic review of the literature, a medical librarian was consulted to develop and perform comprehensive searches in PubMed (1809-present), Embase (embase.com 1974-present), CINAHL (EBSCO, 1937-present), and the Cochrane Central Register of Controlled Trials (Wiley). Final searches resulted in 727 references. Through multiple reviewer screenings and assessments of eligible full-text articles, we included 14 articles for review.

Results

Our systematic review yielded pathologic examination results from 17,388 femoral head specimens collected during THA. In 0.85% of cases, the pathologic diagnosis differed in a meaningful way from the preoperative clinical diagnosis. Routine pathology changed patient management in approximately 0.0058% of cases. The average cost for pathologic examination of each specimen was $126.38.

Conclusion

Routine pathologic examination of femoral heads retrieved during THA has limited impact on patient management. With an estimated 500,000 THAs performed in 2019, the economic feasibility of routine femoral head pathology is limited at an annual cost of up to $63,000,000 and cost per quality-adjusted life-year approaching infinity. However, surgeon discretion on a patient-specific or practice-specific basis should be used to make the final determination on the need for femoral head pathology.

Selective pathological examination following hip arthroplasty: A retrospective cohort study

BACKGROUND

Pathological examination of the femoral head after hip arthroplasty is often performed routinely. The cost-effectiveness of the examination with regard to identifying clinically relevant diagnoses has been a point of discussion. To date, recommendations on performing pathological examination based on patient characteristics, disease history or radiographic findings are scarce. The aim of this study was to gain insight in when to select a patient for pathological examination of the femoral head by means of the following research questions: "How many clinically relevant diagnoses does selective pathological examination identify?" "Which factors contribute to selection of the femoral head for conducting pathological examination?" "What are the costs of selective pathological examination for identifying clinically relevant diagnoses?"

HYPOTHESIS

Selective pathological examination of the femoral head results in higher ratios of identified clinically relevant diagnoses against substantially lower costs.

METHODS

A retrospective cohort study was performed over the period of 2010-2015. All pathological reports were collected from our hospital and screened for resected femoral heads after primary total hip arthroplasty (THA) or primary hemiarthroplasty (HA). The coherence between preoperative diagnosis and postoperative pathological diagnosis was defined as concordant, discrepant or discordant. The aim was to perform logistic regression analysis.

RESULTS

In total, 164 patients were included of 3998 hip arthroplasties performed during the study period with a mean age of 74±12.3 years including 54 (33%) male and 110 (67%) female of whom 112 (68%) underwent THA and 52 (32%) HA. A discrepancy in diagnosis was found in nine patients (6%) and discordance in three patients (2%). The most frequently reported reasons to perform pathological examination were malignancy in medical history n=86 (53%), avascular necrosis n=22 (13%), bone abnormality perioperatively n=19 (11%) and pathological fracture n=13 (8%). The factors that identified the unexpected clinically relevant diagnoses were pathological fracture (3 cases out of 13), bone abnormality perioperatively (2 out of 19), abnormalities on preoperative radiographs (1 out of 9) and to a lesser extent malignancy in history (2 out of 86). With costs of pathological examination of approximately €163 per femoral head, performed in 164 patients, the total costs of pathological examination resulted in €26,732. The cost per discrepant case (n=9) was €2970 and the cost per discordant case (n=3) was €8910.

CONCLUSION

Selective pathological examination of the femoral head following hip arthroplasty results in higher ratios of discrepant and discordant cases against substantially lower costs. Factors that identify clinically relevant diagnoses are pathological fracture, perioperative bone abnormality, abnormalities on preoperative radiographs and to a lesser extent malignancy in history.

LEVEL OF EVIDENCE

III; retrospective cohort study.

Evaluation of the Cost Effectiveness of Routine Histopathologic Femoral Head Analysis in Hip Arthroplasty

Purpose

Histopathologic analysis of femoral head specimens following total hip arthroplasty (THA) is a routine practice that represents a significant use of health care resources. However, it occasionally results in discovery of undiagnosed hematopoietic malignancy and other discrepant diagnoses such as avascular necrosis. The purpose of this study was to determine the rate of discordant and discrepant diagnoses discovered from routine histopathological evaluation of femoral heads following THA and perform a cost analysis of this practice.

Materials and Methods

A review of patients undergoing primary THA between 2004-2017 was conducted. A comparison of the surgeon’s preoperative and postoperative diagnosis, and the histopathologic diagnosis was performed. In cases where the clinical and histopathology differed, a review determined whether this resulted in a change in clinical management. Medicare reimbursement and previously published cost data corrected for inflation were utilized for cost calculations.

Results

A review of 2,134 procedures was performed. The pathologic diagnosis matched the postoperative diagnosis in 96.0% of cases. Eighty-three cases (4.0%) had a discrepant diagnosis where treatment was not substantially altered. There was one case of discordant diagnosis where lymphoma was diagnosed and subsequently treated. The cost per discrepant diagnosis was $141,880 and per discordant diagnosis was $1,669 when using 100% Medicare reimbursement and Current Procedural Terminology (CPT) code combination 88304+88311.

Conclusion

Histopathologic analysis of femoral head specimens in THAs showed an association with high costs given the rarity of discordant diagnoses. Routine use of the practice should be at the discretion of individual hospitals with consideration for cost and utility thresholds.

Unexpected Primary Extranodal Marginal Zone Lymphoma of Bone in Amputation and Arthroplasty Specimens

OBJECTIVES

Amputation due to gangrene and arthroplasty for degenerative joint disease are common orthopedic procedures and are expected to increase as populations age. Histopathologic examination of these specimens can identify unsuspected diseases.

METHODS

We reviewed gangrenous amputations and large joint arthroplasty specimens for diagnosis of unexpected lymphoma, January 2014 to January 2020. Pathology and medical records were reviewed to determine diagnosis, treatment, and outcome.

RESULTS

Five cases (0.08%) of unexpected primary extranodal marginal zone lymphoma (MZL) centered in bone were identified in 1,624 amputations for gangrene and 4,163 arthroplasty specimens. The female-to-male distribution was 3:2. Median age was 71 years (range, 62-87). The 3 cases arising in the setting of gangrene involved the first toe phalanges and metatarsals, and the femoral head was involved in all cases of joint disease (2 cases). The bone showed variable (10%-80%) infiltration by dense populations of small lymphoid cells with MZL immunophenotype. One patient died from sepsis 18.5 months after diagnosis; all others are alive with a median follow-up of 27.45 months.

CONCLUSIONS

Histopathologic examination of nonneoplastic orthopedic specimens identifies unexpected primary bone extranodal MZL in a small percentage of cases. This neoplasm may be the result of chronic antigenic stimulation in some circumstances.

Accurate and Reliable Diagnosis of Avascular Necrosis of the Femoral Head From Total Hip Arthroplasty Specimens Requires Pathologic Examination

OBJECTIVES

To evaluate the necessity of pathologic examination for confirming the diagnosis of avascular necrosis (AVN).

METHODS

We retrospectively reviewed consecutive nonfractured total hip arthroplasty cases (n = 1,722), comparing operative diagnoses and radiologic data with final histologic diagnoses, focusing specifically on AVN.

RESULTS

Among 199 histologically confirmed cases of AVN, 62 (31%) had a preoperative diagnosis of osteoarthritis/degenerative joint disease (OA/DJD); 58 of the latter patients had radiology reports, but only two (3%) documented AVN. Patients with AVN preoperatively diagnosed as OA/DJD were significantly older (mean, 65 years) than patients with AVN correctly diagnosed clinically (mean, 52 years; P < .00001). Among 163 cases with a preoperative diagnosis of AVN, 26 (16%) were confirmed as OA/DJD; the radiology report incorrectly diagnosed AVN in 17 (65%) patients. These latter patients also were significantly older (mean, 60 years) than patients with AVN correctly diagnosed clinically (P = .0008). Patients with a preoperative clinical and/or radiologic diagnosis of AVN were more likely to be younger and have known AVN risk factors.

CONCLUSIONS

Accurate and reliable diagnosis of AVN requires pathologic examination, especially among older patients without known risk factors. Prompt diagnosis may lead to behavioral changes in affected patients that reduce the risk of subsequent lesions.

The Incidence and Significance of Calcium Pyrophosphate Dihydrate Deposits in Histologic Examinations of Total Hip, Knee, and Shoulder Joint Arthroplasties

CONTEXT.—

The incidence, distribution, and significance of calcium pyrophosphate dihydrate deposition (CPPD) disease have not been extensively compared among various total joint resections.

OBJECTIVE.—

To investigate and define the clinical and pathologic features of CPPD in hip, shoulder, and knee arthroplasties.

DESIGN.—

We retrospectively reviewed consecutive total hip, knee, and shoulder arthroplasty cases (N = 3195) confirmed pathologically between January 1, 2017, and October 10, 2018, comparing clinical and pathologic data.

RESULTS.—

Among 2004 hip arthroplasties, 61 (3%) had CPPD on pathologic examination; the majority had a histologic diagnosis of osteoarthritis followed by fracture and avascular necrosis. Of 1113 knee arthroplasties, 98 (9%) had CPPD; all had a histologic diagnosis of osteoarthritis. Among 78 shoulder arthroplasties, 10 (13%) had CPPD; all but one had a histologic diagnosis of osteoarthritis. Patients with hip and knee CPPD were significantly older than those without CPPD. Of the 169 pathologically detected CPPD cases, only 35 (21%) were documented on preoperative radiologic images or by other clinical means; radiology reports were significantly more likely to document chondrocalcinosis in the knees than in the hips. Histologically, CPPD were noted almost exclusively in the separately submitted soft tissues/joint capsule, concomitantly involving the articular cartilage surface in only 3.0% (5 of 169) of cases.

CONCLUSIONS.—

Calcium pyrophosphate dihydrate deposition is more than twice as likely to occur in the knees and shoulders compared with the hips. Patients with CPPD in the knees or hips are usually not recognized preoperatively/radiologically and constitute a significantly older population. Reliably establishing the diagnosis of CPPD requires pathologic examination of the submitted soft tissue/joint capsule.

Assessing the value of screening tools: reviewing the challenges and opportunities of cost-effectiveness analysis

Background

Screening is an important part of preventive medicine. Ideally, screening tools identify patients early enough to provide treatment and avoid or reduce symptoms and other consequences, improving health outcomes of the population at a reasonable cost. Cost-effectiveness analyses combine the expected benefits and costs of interventions and can be used to assess the value of screening tools.

Objective

This review seeks to evaluate the latest cost-effectiveness analyses on screening tools to identify the current challenges encountered and potential methods to overcome them.

Methods

A systematic literature search of EMBASE and MEDLINE identified cost-effectiveness analyses of screening tools published in 2017. Data extracted included the population, disease, screening tools, comparators, perspective, time horizon, discounting, and outcomes. Challenges and methodological suggestions were narratively synthesized.

Results

Four key categories were identified: screening pathways, pre-symptomatic disease, treatment outcomes, and non-health benefits. Not all studies included treatment outcomes; 15 studies (22%) did not include treatment following diagnosis. Quality-adjusted life years were used by 35 (51.4%) as the main outcome. Studies that undertook a societal perspective did not report non-health benefits and costs consistently. Two important challenges identified were (i) estimating the sojourn time, i.e., the time between when a patient can be identified by screening tests and when they would have been identified due to symptoms, and (ii) estimating the treatment effect and progression rates of patients identified early.

Conclusions

To capture all important costs and outcomes of a screening tool, screening pathways should be modeled including patient treatment. Also, false positive and false negative patients are likely to have important costs and consequences and should be included in the analysis. As these patients are difficult to identify in regular data sources, common treatment patterns should be used to determine how these patients are likely to be treated. It is important that assumptions are clearly indicated and that the consequences of these assumptions are tested in sensitivity analyses, particularly the assumptions of independence of consecutive tests and the level of patient and provider compliance to guidelines and sojourn times. As data is rarely available regarding the progression of undiagnosed patients, extrapolation from diagnosed patients may be necessary.