The Journal of Bone & Joint Surgery

The Journal of Bone & Joint Surgery, Volume 88, Issue 10

Scientific Articles | October 01, 2006

Bilateral Total Knee Replacement: Staging and Pulmonary Embolism

Jane Barrett, MSc¹; John A. Baron, MD, MSc¹; Elena Losina, PhD²; John Wright, MD³; Nizar N. Mahomed, MD, ScD⁴; Jeffrey N. Katz, MD, MS³

¹ Departments of Medicine (J.A.B.) and Community and Family Medicine (J.B. and J.A.B.), and Section of Biostatistics and Epidemiology (J.B. and J.A.B.), Dartmouth Medical School, 46 Centerra Parkway, Evergreen Building, Suite 300, Lebanon, NH 03766. E-mail address for J. Barrett: jane.a.barrett@dartmouth.edu
² Department of Biostatistics, Boston University School of Public Health, 715 Albany Street, TE421, Boston, MA 02118
³ Section of Clinical Sciences, Division of Rheumatology, Immunology and Allergy (J.N.K.), and Department of Orthopaedic Surgery (J.W. and J.N.K.) Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115
⁴ Musculoskeletal Health and Arthritis Program, Toronto Western Hospital, University Health Network, University of Toronto, 399 Bathurst Street, Toronto, ON M5T 2S8, Canada

View Disclosures and Other Information

In support of their research for or preparation of this manuscript, one or more of the authors received grants or outside funding from the National Institute of Arthritis and Musculoskeletal and Skin Diseases and the National Institutes of Health. None of the authors 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, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.

Investigation performed at Dartmouth Medical School, Lebanon, New Hampshire and Brigham and Women's Hospital, Boston, Massachusetts

The Journal of Bone and Joint Surgery, Incorporated

J Bone Joint Surg Am, 2006 Oct 01;88(10):2146-2151. doi: 10.2106/JBJS.E.01323

5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

Article

Comments (0)

text A A A

Abstract

Background: When a bilateral total knee replacement is indicated, it is not clear whether it is preferable to operate on both knees during the same hospitalization (simultaneously) or to stage the procedures in two separate hospital stays. A greater risk of pulmonary embolism after simultaneous total knee replacement has been reported by some authors, but little national data are available.

Methods: We reviewed the records of 122,385 United States Medicare enrollees who had had a total knee replacement in 2000. We noted whether they had had a unilateral procedure or two procedures and, if they had had two procedures, whether both had been done during the same hospitalization or whether the operations had been performed during two separate hospital stays. Age, sex, race, residence, Medicaid eligibility (a proxy for low income), and the Charlson comorbidity score were documented for each patient as were the total numbers of total knee replacements performed in the year 2000 by the hospital and the surgeon. The probability of a symptomatic pulmonary embolism developing in the first three months after surgery was calculated for the simultaneous, staged, and unilateral procedures.

Results: Simultaneous procedures were much more likely to be performed in high-volume hospitals and by high-volume surgeons than were staged procedures. Men had proportionately more simultaneous procedures than did women. Hospitals in the northeastern United States were the most likely to perform simultaneous procedures. A pulmonary embolism developed in the first three months in 0.81% of the patients who had had a single procedure compared with 1.44% of the patients who had undergone a simultaneous procedure (adjusted hazard ratio 1.81; 95% confidence interval, 1.49, 2.20).

Conclusions: The systematic differences in patient gender, hospital and surgeon volume, and geographic region between those who undergo simultaneous total knee replacements and those who undergo staged procedures should be borne in mind when outcomes are being compared. The adjusted risk of pulmonary embolism is about 80% higher in the three months after a simultaneous procedure than in the three months after a single procedure, which suggests that the sum of the risks associated with the two operations of a staged procedure may equal or exceed the risk of simultaneous total knee replacement.

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Figures in this Article

When a bilateral total knee replacement is indicated, it is not clear whether both knees should be operated on during the same hospitalization (simultaneous bilateral total knee replacement) or whether it is better to wait until the patient has recovered from the first total knee replacement before the second procedure is carried out during a second hospital stay (staged bilateral total knee replacement). An important consideration in the choice of whether to perform a simultaneous or staged bilateral total knee replacement is the risk of serious complications such as pulmonary embolism. Some authors have reported a greater perioperative risk of pulmonary embolism after simultaneous bilateral knee replacements than after unilateral procedures^1,2. Other large studies have demonstrated an increased risk of all thromboembolic and/or pulmonary complications following simultaneous replacement^3-6. Several other investigations have shown no significant difference in the risk of perioperative thromboembolism between bilateral and unilateral total knee replacements^7-11, but those studies had relatively small numbers of patients and therefore low power to detect differences between the two groups. In one single-center study, the complication rate associated with a simultaneous total knee replacement was found to be actually lower than that following a unilateral procedure¹². Consequently, it is not clear whether a staged set of procedures is preferable to a simultaneous approach. Moreover, little is known regarding the characteristics of patients who receive each of the two types of intervention. Ritter et al. described the demographic characteristics of Medicare recipients who had undergone bilateral total knee replacement between 1985 and 1990¹³, but to our knowledge no other national population-based description of bilateral total knee replacement has appeared in print.

In this study, we compared all Medicare recipients who had had a simultaneous bilateral procedure in 2000 with those who had had a staged bilateral procedure (with one of the operations performed in 2000). We compared the two groups with regard to their demographic attributes, comorbidities, geographic distribution, hospital and surgeon volume, and probability of pulmonary embolism in the first three months postoperatively.

Materials and Methods

Materials and Methods | Results | Discussion | References

This study focused on Medicare beneficiaries who had received a total knee replacement in 1999, 2000, or 2001. Medicare claims submitted by hospitals (Medicare Part A) and by surgeons (Medicare Part B) in 2000 were used to define the index primary total knee replacement. These procedures were identified by a hospital claim with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)¹⁴ procedure code 81.54 (total knee replacement) together with a surgeon's claim with Current Procedural Terminology (CPT) Fourth Edition¹⁵ code 27447 (arthroplasty, knee, condyle and plateau; medial and lateral components with or without patella resurfacing [total knee replacement]). To focus on elective total knee replacement, we excluded from the study cohort patients with claims indicating preexisting infection of the knee, metastatic cancer, or bone cancer. In order to obtain complete hospital claim histories for the years 1999, 2000, and 2001, we also excluded patients enrolled in health maintenance organizations, those not enrolled in both parts of Medicare, those who were not residents in the United States, and those who were less than sixty-six years of age at the time of the index surgery in 2000. If a patient had had a total knee replacement during more than one hospitalization in 2000, the first hospitalization was considered to be the index hospitalization.

When a patient had had an index total knee replacement in 2000, hospital claims were searched for any other total knee replacement in 1999, 2000, or 2001. When the index hospital claim had two ICD-9-CM procedure codes indicating total knee replacement (81.54), the event was considered to be a simultaneous bilateral procedure. We found it impossible to determine reliably from the claims data whether a given simultaneous bilateral total knee replacement had been done as a double procedure during a single anesthesia session or as sequential procedures during the same hospitalization with two separate anesthesia sessions. A patient was considered to have had a staged procedure if another total knee replacement had been done in 1999, 2000, or 2001 but not during the same hospitalization as the index procedure.

Characteristics of Medicare Patients with a Simultaneous

Total Knee Replacement and Those with a Staged Procedure Bivariate relationships between demographic variables and provider procedure volume on the one hand and staging status (simultaneous or staged less than a year apart) on the other were examined with contingency tables and the chi-square test. The demographic factors included age group, gender, race, census division of the United States, and eligibility for Medicaid supplement (a marker of low income). In addition, an adaptation of the Charlson index of comorbidity^16,17 was calculated with use of inpatient claims data for the hospitalization for the first total knee replacement. The relationships between the staging status and the total number of total knee replacements performed in 2000 on Medicare beneficiaries by the hospital and by the surgeon were also examined. A multivariate logistic regression analysis was then performed to identify factors associated with having a simultaneous total knee replacement rather than two procedures staged less than a year apart, with adjustment for all of the above variables.

Pulmonary Embolism After Total Knee Replacement

We examined the probability of a symptomatic pulmonary embolism developing in the first three months after the first total knee replacement for all patients. A diagnosis of pulmonary embolism was ascertained by searching for hospital claims (including those for the index hospitalization) with an ICD-9-CM code of 415.1-415.19 (pulmonary embolism and infarction: iatrogenic or other). We used actuarial life-table techniques to estimate the proportion of patients in each group who had a pulmonary embolism in the first three months after surgery. Life tables tally the events of subjects during the separate short intervals of time that each subject is being followed. From these data, it is possible to estimate event rates over various time intervals while taking into account the fact that some subjects have died or have been lost to follow-up^18,19.

In addition, we performed proportional hazards regression analysis to estimate the pulmonary embolism hazard for patients undergoing simultaneous bilateral procedures relative to all other patients, with adjustment for the demographic, comorbidity, and hospital and surgeon-volume characteristics listed above. All analyses were carried out with use of SAS statistical software (release 8.2; SAS Institute, Cary, North Carolina). The critical p value for significance was 0.05.

Results

Materials and Methods | Results | Discussion | References

We identified 122,385 eligible patients as having had an index total knee replacement in 2000 (Table I). Of these patients, 8324 (6.8%) had two total knee replacements during the same hospitalization (simultaneous total knee replacement) and 13,039 (10.7%) had another staged total knee replacement within a year before or after the index hospitalization; 4957 patients (4.1%) had two total knee replacements between one and two years apart. The remaining 96,065 patients (78.5%), who had no other total knee replacement in 1999, 2000, or 2001, were considered to have had a unilateral total knee replacement.

View Larger

TABLE I Distribution of Staging of Primary Total Knee Replacements Performed in 2000 in Medicare Recipients More than Sixty-five Years Old

Total Knee Replacement	No. of Patients	% of All Patients with Total Knee Replacement
Unilateral (no other total knee replacement in 1999-2001)	96,065	78.5
Simultaneous bilateral (same hospitalization)	8324	6.8
Staged bilateral	17,996	14.7
<3 mo apart	1663	1.4
3-6 mo apart	4146	3.4
6-12 mo apart	7230	5.9
1-2 yr apart	4957	4.1
All patients	122,385	100.0

Add to My JBJS

TABLE I Distribution of Staging of Primary Total Knee Replacements Performed in 2000 in Medicare Recipients More than Sixty-five Years Old

Total Knee Replacement	No. of Patients	% of All Patients with Total Knee Replacement
Unilateral (no other total knee replacement in 1999-2001)	96,065	78.5
Simultaneous bilateral (same hospitalization)	8324	6.8
Staged bilateral	17,996	14.7
<3 mo apart	1663	1.4
3-6 mo apart	4146	3.4
6-12 mo apart	7230	5.9
1-2 yr apart	4957	4.1
All patients	122,385	100.0

Characteristics of Medicare Patients with a Simultaneous Total Knee Replacement and Those with a Staged Procedure

The bivariate analyses showed that the simultaneous total knee replacements were much more likely than the staged procedures to have been done in high-volume hospitals and by high-volume surgeons (Table II). The simultaneous procedures were also more likely than the staged procedures to have been carried out in men and in whites and were less likely to have been carried out in low-income patients (those with Medicaid coverage). Simultaneous procedures were much less common in the Pacific states than elsewhere. Very little difference in the Charlson comorbidity index scores was seen between the simultaneous and staged-procedure groups.

View Larger

TABLE II Association Between Staging Status of Bilateral Total Knee Replacement and Demographic and Volume Variables at Time of First Replacement

	Bilateral Total Knee Replacement
	Simultaneous* (N = 8324)	Staged <1 Yr Apart* (N = 13,039)	Chi-Square Probability
Age group			0.26
=74 yr	57.4%	57.6%
75-84 yr	39.0%	38.4%
=85 yr	3.6%	4.0%
Gender			<0.0001
Male	42.2%	37.1%
Female	57.8%	62.9%
Race			<0.0001
White	94.0%	92.3%
Black	4.1%	5.0%
Other/unknown	1.9%	2.7%
Medicaid status			<0.0001
No	94.3%	91.5%
Yes	5.7%	8.5%
Charlson score			0.17
0	65.1%	64.5%
1	21.4%	22.4%
=2	13.5%	13.0%
Census division of USA			<0.0001
New England	5.2%	4.6%
Mid-Atlantic	13.0%	11.4%
South Atlantic	19.8%	18.9%
East-north central	23.7%	21.2%
East-south central	6.1%	5.5%
West-north central	12.1%	13.0%
West-south central	9.0%	10.5%
Mountain	6.1%	5.9%
Pacific	5.1%	9.0%
Hospital volume of procedures/yr			<0.0001
1-25	4.7%	10.9%
26-100	31.0%	40.7%
101-200	30.0%	29.6%
=201	34.3%	18.8%
Surgeon volume of procedures/yr			<0.0001
1-12	11.2%	24.4%
13-25	20.6%	27.1%
26-50	25.6%	26.4%
=51	42.5%	22.1%

All percents are expressed as column percents.

Add to My JBJS

TABLE II Association Between Staging Status of Bilateral Total Knee Replacement and Demographic and Volume Variables at Time of First Replacement

	Bilateral Total Knee Replacement
	Simultaneous* (N = 8324)	Staged <1 Yr Apart* (N = 13,039)	Chi-Square Probability
Age group			0.26
=74 yr	57.4%	57.6%
75-84 yr	39.0%	38.4%
=85 yr	3.6%	4.0%
Gender			<0.0001
Male	42.2%	37.1%
Female	57.8%	62.9%
Race			<0.0001
White	94.0%	92.3%
Black	4.1%	5.0%
Other/unknown	1.9%	2.7%
Medicaid status			<0.0001
No	94.3%	91.5%
Yes	5.7%	8.5%
Charlson score			0.17
0	65.1%	64.5%
1	21.4%	22.4%
=2	13.5%	13.0%
Census division of USA			<0.0001
New England	5.2%	4.6%
Mid-Atlantic	13.0%	11.4%
South Atlantic	19.8%	18.9%
East-north central	23.7%	21.2%
East-south central	6.1%	5.5%
West-north central	12.1%	13.0%
West-south central	9.0%	10.5%
Mountain	6.1%	5.9%
Pacific	5.1%	9.0%
Hospital volume of procedures/yr			<0.0001
1-25	4.7%	10.9%
26-100	31.0%	40.7%
101-200	30.0%	29.6%
=201	34.3%	18.8%
Surgeon volume of procedures/yr			<0.0001
1-12	11.2%	24.4%
13-25	20.6%	27.1%
26-50	25.6%	26.4%
=51	42.5%	22.1%

All percents are expressed as column percents.

The strong associations with hospital and surgeon volume were confirmed by the logistic regression analysis, as was the finding that men had proportionately more simultaneous procedures than did women (Table III). When procedure volume and other covariates were taken into account, an east-west pattern became apparent. Hospitals in northeastern states were the most likely to perform simultaneous procedures, followed by those in other states east of the Mississippi River and by the Rocky Mountain states. Hospitals in the west-central and Pacific divisions were the least likely to perform simultaneous procedures.

View Larger

TABLE III Results of Logistic Regression Analysis of Factors Associated with Simultaneous Bilateral Total Knee Replacement as Opposed to Replacements Staged Less Than One Year Apart

	Odds Ratio	95% Confidence Interval
Gender
Male	1.00	—
Female	0.84	0.79-0.90
Race
White	1.00	—
Black	0.98	0.83-1.14
Other/unknown	0.94	0.75-1.18
Age group
=74 yr	1.00	—
75-84 yr	1.01	0.95-1.08
=85 yr	0.91	0.77-1.08
Medicaid status
No	1.00	—
Yes	0.88	0.77-1.01
Charlson score
0	1.00	—
1	0.94	0.87-1.01
=2	0.95	0.86-1.04
Census division of USA
New England	1.00	—
Mid-Atlantic	0.94	0.79-1.11
South Atlantic	0.71	0.61-0.83
East-north central	0.82	0.70-0.96
East-south central	0.87	0.72-1.06
West-north central	0.60	0.51-0.71
West-south central	0.60	0.50-0.71
Mountain	0.78	0.64-0.94
Pacific	0.56	0.47-0.68
Hospital volume of procedures/yr
1-25	1.00	—
26-100	1.37	1.19-1.56
101-200	1.43	1.24-1.65
=201	2.25	1.94-2.61
Surgeon volume of procedures/yr
1-12	1.00	—
13-25	1.58	1.42-1.75
26-50	1.93	1.74-2.13
=51	3.23	2.91-3.60

Add to My JBJS

TABLE III Results of Logistic Regression Analysis of Factors Associated with Simultaneous Bilateral Total Knee Replacement as Opposed to Replacements Staged Less Than One Year Apart

	Odds Ratio	95% Confidence Interval
Gender
Male	1.00	—
Female	0.84	0.79-0.90
Race
White	1.00	—
Black	0.98	0.83-1.14
Other/unknown	0.94	0.75-1.18
Age group
=74 yr	1.00	—
75-84 yr	1.01	0.95-1.08
=85 yr	0.91	0.77-1.08
Medicaid status
No	1.00	—
Yes	0.88	0.77-1.01
Charlson score
0	1.00	—
1	0.94	0.87-1.01
=2	0.95	0.86-1.04
Census division of USA
New England	1.00	—
Mid-Atlantic	0.94	0.79-1.11
South Atlantic	0.71	0.61-0.83
East-north central	0.82	0.70-0.96
East-south central	0.87	0.72-1.06
West-north central	0.60	0.51-0.71
West-south central	0.60	0.50-0.71
Mountain	0.78	0.64-0.94
Pacific	0.56	0.47-0.68
Hospital volume of procedures/yr
1-25	1.00	—
26-100	1.37	1.19-1.56
101-200	1.43	1.24-1.65
=201	2.25	1.94-2.61
Surgeon volume of procedures/yr
1-12	1.00	—
13-25	1.58	1.42-1.75
26-50	1.93	1.74-2.13
=51	3.23	2.91-3.60

Pulmonary Embolism After Total Knee Replacement

In the first three months after total knee replacement, the probability of having a symptomatic pulmonary embolism, as estimated from life tables (which take into account early deaths), was 1.44% for patients who had had a simultaneous bilateral procedure, 0.87% for patients who had had a unilateral procedure, and 0.54% for patients who had had the first of two staged procedures. The difference among the three groups was highly significant (log-rank p < 0.0001). In the group of patients who had undergone staged procedures, we found no clinically meaningful differences in the rate of pulmonary embolism after the first procedure according to how far apart the procedures had been staged.

The occurrence of a pulmonary embolism after a single procedure could well mean that a second procedure had been planned but had not taken place because of the complication, so that the patient appeared to have had a unilateral procedure in our dataset. When we grouped all 114,061 patients who had had a unilateral or staged procedure, we found, on the basis of life-table estimates, that the probability of a pulmonary embolism developing in the first three months after the first (or only) procedure was 0.81%. This was a little more than half of the 1.44% three-month probability of pulmonary embolism following the simultaneous procedures, a difference that was again highly significant (log-rank p < 0.0001). In the proportional hazards model, which took into account the demographic, geographic, comorbidity, and hospital and surgeon-volume variables listed in Table III that might affect the rate of pulmonary embolism within the first three months after surgery, the hazard ratio for the patients who had undergone simultaneous bilateral procedures compared with those who had had a single procedure was 1.81 (95% confidence interval, 1.49, 2.20). This finding suggests that the overall risk following two-staged procedures is comparable with that following simultaneous procedures.

Discussion

Materials and Methods | Results | Discussion | References

In this analysis of Medicare patients who had undergone total knee replacement in 1999, 2000, or 2001, we found that high-volume hospitals and surgeons were much more likely to carry out simultaneous total knee replacements than were their low-volume counterparts. An east-west geographic pattern could also be seen, with hospitals in northeastern states most likely to perform simultaneous procedures, even when hospital and surgeon volume was taken into account. Simultaneous procedures were more likely to be carried out on men than on women, a finding that agrees with the earlier observations of Ritter et al.¹³.

Our estimates of the probability of a symptomatic pulmonary embolism developing within three months after staged surgery should be interpreted with caution. All patients who appear in our dataset as having had staged bilateral total knee replacement had to have survived the initial procedure to undergo the second. Any patient who died after the first planned procedure was listed in our dataset as having had a unilateral procedure and then died. Also, if a patient for whom a staged procedure had been planned had a pulmonary embolism, myocardial infarct, or other serious consequence after the first total knee replacement, the second procedure might well have been cancelled. Again, the adverse event would appear in our claims data to have happened to a patient treated with unilateral total knee replacement rather than to a patient for whom a staged procedure had been planned. We suspect that this selection bias largely explains why the pulmonary embolism rate for the patients who had undergone the first of two staged total knee replacements was lower than that for the patients who had undergone unilateral total knee replacement. In contrast, all outcomes after simultaneous procedures were counted as occurring after simultaneous procedures. Given that we do not know the initial intentions of the patients, it is more appropriate to compare those who had simultaneous bilateral total knee replacement with all of those who had a single total knee replacement during the first hospital stay, whether or not a second procedure was ever done. Our three-month pulmonary embolism probability estimates of 1.44% for simultaneous procedures compared with 0.81% for all single total knee replacements are similar to those in other large studies that demonstrated a higher probability of perioperative pulmonary embolism or thromboembolism after simultaneous procedures than after single total knee replacements^1,3,4,6. Assuming that the probability of pulmonary embolism developing after the second staged procedure is no less than the probability of it developing after the first, this suggests that the sum of the two risks associated with a staged procedure may equal or exceed the risk associated with a simultaneous total knee replacement, although the absolute risk is low in either case.

It could be argued that differences between the simultaneous-procedure group and the other groups with regard to demographic variables and hospital and surgeon volume could account for part of the difference between the risk of pulmonary embolism after a simultaneous procedure and that after a single total knee replacement. However, the risk of pulmonary embolism in the three months after total knee replacement varies hardly at all by sex, race, or hospital or surgeon volume and only modestly by age^20,21. Furthermore, our proportional hazards model confirmed that the hazard ratio of about 1.8 did not change substantially when those variables were taken into account. It is possible, however, that there was some residual confounding, particularly in our measure of comorbidity, which was derived from the diagnoses at the time of discharge from the hospitalization for the first total knee replacement.

The increased operative time involved in a simultaneous bilateral procedure, the surgical intervention in both lower extremities (where the emboli typically originate), and perhaps a more prolonged period of relative immobility constitute possible explanations for the increased risk of pulmonary embolism after the simultaneous procedures compared with the risk after the single total knee replacements.

The nature of Medicare data imposed several important limitations on our study. Reliable information is available only for patients who are sixty-five years of age or older, and about 30% of all total knee replacements are performed on people younger than sixty-five²². Also, it is impossible to determine whether, in a given case, the simultaneous total knee replacements were both performed in a single session in the operating room with a single anesthesia session or whether they were sequential procedures done during the same hospitalization with two sessions of anesthesia. There may well be different clinical outcomes in these different scenarios^23,24. It is likely that pulmonary embolism rates calculated from Medicare and similar databases are underestimated. In particular, fatal pulmonary embolisms occurring outside of a hospital and asymptomatic pulmonary embolisms are not represented in hospital claims. Underreporting should, however, affect all groups in much the same way, leaving the differences between groups more or less unaffected. Furthermore, there is no information in the Medicare database about the use of prophylaxis for pulmonary embolism.

There are also important advantages of using the Medicare database. The program covers virtually all Americans over the age of sixty-five, so the referral bias of single-center studies is eliminated. Outcomes can be traced even if a patient moves from state to state. The large numbers of total knee replacements performed permit precise estimates of outcome risks for the entire United States.

We found that approximately 22% (26,320 of 122,385) of all Medicare patients who have a total knee replacement have a bilateral knee replacement, with either both procedures done during the same hospitalization or on separate occasions within two years. Among patients treated with bilateral total knee replacement, those who have simultaneous procedures are more likely than those who have staged procedures to be male, have a higher income, reside in the northeastern part of the United States, and have their procedures performed in a high-volume center by a high-volume surgeon. The risk of pulmonary embolism is about 80% higher in patients who have had a simultaneous bilateral procedure than it is in those who have had the first procedure of a staged bilateral replacement or have had a unilateral replacement, although the absolute risk is low in either case. This suggests that the sum of the two risks of a staged procedure may equal or exceed the risk of simultaneous total knee replacement. On the other hand, staging the total knee replacement results in a lower initial probability of pulmonary embolism and then allows the choice of proceeding with the second total knee replacement or not, depending on the result of the first. This approach may appeal to some patients.

These data have important implications for decision-making regarding the treatment of patients with two arthritic knees. Patients and physicians should use data such as these to discuss the relative advantages and drawbacks of the different strategies for undertaking a bilateral total knee replacement and make choices consonant with their preferences.

These findings may also have policy implications. A program that shifts patients from low to high-volume centers might correspondingly increase the relative frequency of simultaneous bilateral procedures as compared with staged bilateral procedures, which could result in a somewhat lower risk of pulmonary embolism. ?

References

Materials and Methods | Results | Discussion | References

Mantilla CB, Horlocker TT, Schroeder DR, Berry DJ, Brown DL. Frequency of myocardial infarction, pulmonary embolism, deep venous thrombosis, and death following primary hip or knee arthroplasty. Anesthesiology. 2002;96: 1140-6. Erratum in: Anesthesiology. 2002;97:531.961140 2002 [PubMed][CrossRef]

Messieh M. Preoperative risk factors associated with symptomatic pulmonary embolism after total knee arthroplasty. Orthopedics. 1999;22: 1147-9.221147 1999 [PubMed]

Ritter MA, Harty LD, Davis KE, Meding JB, Berend M. Simultaneous bilateral, staged bilateral, and unilateral total knee arthroplasty. A survival analysis. J Bone Joint Surg Am. 2003;85: 1532-7.851532 2003 [PubMed]

O'Reilly RF, Burgess IA, Zicat B. The prevalence of venous thromboembolism after hip and knee replacement surgery. Med J Aust. 2005;182: 154-9.182154 2005 [PubMed]

March LM, Cross M, Tribe KL, Lapsley HM, Courtenay BG, Cross MJ, Brooks PM, Cass C, Coolican M, Neil M, Pinczewski L, Quain S, Robertson F, Ruff S, Walter W, Zicat B; Arthritis C.O.S.T. Study Project Group. Two knees or not two knees? Patient costs and outcomes following bilateral and unilateral total knee joint replacement surgery for OA. Osteoarthritis Cartilage. 2004;12: 400-8.12400 2004 [PubMed][CrossRef]

Lombardi AV, Mallory TH, Fada RA, Hartman JF, Capps SG, Kefauver CA, Dodds K, Adams JB. Simultaneous bilateral total knee arthroplasties: who decides? Clin Orthop Relat Res. 2001;392: 319-29.392319 2001 [PubMed][CrossRef]

Kim YH, Kim JS. Incidence and natural history of deep-vein thrombosis after total knee arthroplasty. A prospective, randomised study. J Bone Joint Surg Br. 2002;84: 566-70.84566 2002 [PubMed][CrossRef]

Jankiewicz JJ, Sculco TP, Ranawat CS, Behr C, Tarrentino S. One-stage versus 2-stage bilateral total knee arthroplasty. Clin Orthop Relat Res. 1994;309: 94-101.30994 1994 [PubMed]

Lane GJ, Hozack WJ, Shah S, Rothman RH, Booth RE Jr, Eng K, Smith P. Simultaneous bilateral versus unilateral total knee arthroplasty. Outcomes analysis. Clin Orthop Relat Res. 1997;345: 106-12.345106 1997 [PubMed]

Lynch NM, Trousdale RT, Ilstrup DM. Complications after concomitant bilateral total knee arthroplasty in elderly patients. Mayo Clin Proc. 1997; 72: 799-805.72799 1997 [PubMed][CrossRef]

Bullock DP, Sporer SM, Shirreffs TG Jr. Comparison of simultaneous bilateral with unilateral total knee arthroplasty in terms of perioperative complications. J Bone Joint Surg Am. 2003;85: 1981-6.851981 2003 [PubMed]

Worland RL, Jessup DE, Clelland C. Simultaneous bilateral total knee replacement versus unilateral replacement. Am J Orthop. 1996;25: 292-5.25292 1996 [PubMed]

Ritter M, Mamlin LA, Melfi CA, Katz BP, Freund DA, Arthur DS. Outcome implications for the timing of bilateral total knee arthroplasties. Clin Orthop Relat Res. 1997;345: 99-105.34599 1997 [PubMed]

ICD-9-CM 2000: International classification of diseases 9th revision, clinical modification 5th edition: office edition, volumes 1, 2, and 3. Los Angeles: Practice Management Information Corporation (PMIC); 2000.1, 2, and 3 2000

American Medical Association. CPT 2000: Current procedural terminology. Los Angeles: Practice Management Information Corporation; 2000. 2000

Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40: 373-83.40373 1987 [CrossRef]

Romano PS, Roos LL, Jollis JG. Adapting a clinical comorbidity index for use with ICD-9-CM administrative data: differing perspectives. J Clin Epidemiol. 1993;46: 1075-90.461075 1993 [PubMed][CrossRef]

Lee ET. Statistical methods for survival data analysis. New York: Wiley-Interscience; 1992. 1992

Hosmer DW, Lemeshow S. Applied survival analysis: regression modeling of time to event data. New York: Wiley-Interscience; 1998. 1998

Mahomed NN, Barrett J, Katz JN, Baron JA, Wright J, Losina E. Epidemiology of total knee replacement in the United States Medicare population. J Bone Joint Surg Am. 2005;87: 1222-8.871222 2005 [PubMed][CrossRef]

Katz JN, Barrett J, Mahomed NN, Baron JA, Wright RJ, Losina E. Association between hospital and surgeon procedure volume and the outcomes of total knee replacement. J Bone Joint Surg Am. 2004;86: 1909-16.861909 2004

Agency for Health Care Quality and Research: H-CUPnet. .
hcup.ahrq.gov/HCUPnet.asp.2005

Sliva CD, Callaghan JJ, Goetz DD, Taylor SG. Staggered bilateral total knee arthroplasty performed four to seven days apart during a single hospitalization. J Bone Joint Surg Am. 2005;87: 508-13.87508 2005 [PubMed][CrossRef]

Oakes DA, Hanssen AD. Bilateral total knee replacement using the same anesthetic is not justified by assessment of the risks. Clin Orthop Relat Res. 2004;428: 87-91.42887 2004 [PubMed][CrossRef]

Topics

pulmonary embolism ; medicare ; knee replacement arthroplasty ; staged operation

Username

Password

Access for Patients

Forgot Password?

Have a subscription to the print edition?

Not a Subscriber?

Buy this Article

Get online access for 30 days for $35

New to JBJS?

Subscribe to the online edition for 30 days for $75

Register for a FREE limited account to get full access to all CME activities, to comment on public articles, or to sign up for alerts.

Have a subscription to the print edition?

Current subscribers to The Journal of Bone & Joint Surgery in either the print or quarterly DVD formats receive free online access to JBJS.org.

Activate your online account now

Forgot your password?

Enter your username and email address. We'll send you a reminder to the email address on record.

Username:*

Email Address:*

Forgot your username or need assistance? Please contact customer service at subs@jbjs.org. If your access is provided
by your institution, please contact you librarian or administrator for username and password information. Institutional
administrators, to reset your institution's master username or password, please contact subs@jbjs.org

References

Accreditation Statement

These activities have been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint sponsorship of the American Academy of Orthopaedic Surgeons and The Journal of Bone and Joint Surgery, Inc. The American Academy of Orthopaedic Surgeons is accredited by the ACCME to provide continuing medical education for physicians.

CME Activities Associated with This Article

Submit a Comment

Please read the other comments before you post yours. Contributors must reveal any conflict of interest.
Comments are moderated and will appear on the site at the discretion of JBJS editorial staff.

* = Required Field

Comment Author(s) * (if multiple authors, separate names by comma)

Example: John Doe

Affiliation & Institution*

Comment Title*

Comment*

Cancel

Print
PDF
Email

Recipient(s) will receive an email with a link (good for 5 days) to 'Bilateral Total Knee Replacement: Staging and Pulmonary Embolism'.
Your Name:*
Example: John Doe

Email Address:* CC Me:
Enter your valid email address. Example: jdoe@example.com

Recipient's Email Address:*

Separate multiple email address with semi-colons (up to 5).

Subject:* 's The Journal of Bone & Joint Surgery: 'Bilateral Total Knee Replacement: Staging and Pulmonary Embolism'
Subject for your email.

Message:

(Optional, message will truncate at 1000 characters)

Processing your request... Please Wait...

Copyright © in the material you requested is held by The Journal of Bone & Joint Surgery, Inc. (unless otherwise noted). This email ability is provided as a courtesy, and by using it you agree that that you are requesting the material solely for personal, non-commercial use, and that it is subject to Journal of Bone & Joint Surgery, Inc.'s Terms of Use. The information provided in order to email this topic will not be used to send unsolicited email, nor will it be furnished to third parties. Please refer to The Journal of Bone & Joint Surgery Inc.'s Privacy Policy for further information.

Copyright © The Journal of Bone & Joint Surgery Inc. All rights reserved.
Share
Get Citation

Jane Barrett, John A. Baron, Elena Losina, John Wright, Nizar N. Mahomed, Jeffrey N. Katz; Bilateral Total Knee Replacement: Staging and Pulmonary Embolism. The Journal of Bone & Joint Surgery. 2006 Oct;88(10):2146-2151.

Download citation file:

RIS (Zotero)

EndNote

BibTex

Medlars

ProCite

RefWorks

Reference Manager

Copyright © The Journal of Bone and Joint Surgery, Inc.
Rights & Permissions
Article Alerts

Processing your request... Please Wait.
Submit a Comment