Dr. Bogoch has received consulting fees, speaking fees, and/or honoraria from Merck Frosst Canada and Merck Sharpe & Dohme (more than $10,000 each) and has received research support as a principal investigator from Amgen Canada, Novartis Canada, and Warner Chilcott.
Increased Surgeon Experience With Rheumatoid Arthritis Reduces the Risk of Complications Following Total Joint Arthroplasty†
Article first published online: 25 FEB 2014
Copyright © 2014 by the American College of Rheumatology
Arthritis & Rheumatology
Volume 66, Issue 3, pages 488–496, March 2014
How to Cite
Ravi, B., Croxford, R., Austin, P. C., Hollands, S., Paterson, J. M., Bogoch, E., Kreder, H. and Hawker, G. A. (2014), Increased Surgeon Experience With Rheumatoid Arthritis Reduces the Risk of Complications Following Total Joint Arthroplasty. Arthritis & Rheumatology, 66: 488–496. doi: 10.1002/art.38205
The opinions, results, and conclusions reported herein are those of the authors and are independent from the funding sources. No endorsement by the Institute for Clinical Evaluative Sciences or the Ontario Ministry of Health and Long-Term Care is intended or should be inferred.
- Issue published online: 25 FEB 2014
- Article first published online: 25 FEB 2014
- Accepted manuscript online: 21 OCT 2013 10:58AM EST
- Manuscript Accepted: 19 SEP 2013
- Manuscript Received: 22 JUL 2013
- Canadian Institutes of Health Research (CIHR)
- Institute for Clinical Evaluative Sciences
- Ontario Ministry of Health and Long-Term Care
- CIHR Doctoral Research award
- Heart and Stroke Foundation Career Investigator award
- F. M. Hill Chair in Academic Women's Medicine at the University of Toronto
To determine the relationship between surgeon experience with, and complications following, total joint arthroplasty (TJA) in patients with rheumatoid arthritis (RA).
Using administrative data, we assembled a cohort of patients with RA who had undergone at least 1 elective primary hip or knee replacement procedure between 2002 and 2009. Cox proportional hazards, censored on death and accounting for clustering of patients within surgeons, were used to determine the relationship between overall and “RA-specific” surgeon TJA volume and the occurrence of a composite “complication” outcome (revision, infection, dislocation, or periprosthetic fracture within 2 years of the initial TJA), controlling for potential confounders (patient age, sex, comorbidity, and disease severity).
We identified 4,762 patients with RA who were eligible for TJAs (1,515 total hip arthroplasties and 3,247 total knee arthroplasties). Among these patients, 152 (3.2%) experienced a surgical complication within 2 years of the procedure. After controlling for patient and hospital factors, greater surgeon TJA volume in patients with RA (RA TJA), but not overall TJA volume (all TJA), was associated with a reduced risk of complications (for surgeon RA TJA volume per 10 cases, adjusted hazard ratio [HR] 0.81, 95% confidence interval [95% CI] 0.71–0.93, P = 0.002; for surgeon all TJA volume, adjusted HR 0.98, 95% CI 0.97–1.00, P = 0.09).
In a cohort of patients with RA who underwent hip or knee TJA, increased surgeon experience performing TJA in patients with RA, irrespective of their overall TJA experience and hospital factors, was associated with a decreased risk of surgical complications. These findings have potential implications for surgeon training and the referral practices of rheumatologists.
Volume–outcome relationships have been demonstrated for total joint arthroplasty (TJA) ([1-4]), with the risk of surgical complications being roughly inversely proportional to the annual surgeon volume (defined as the number of TJAs performed by the surgeon in the 365 days prior to the index procedure) (). Although most patients undergoing TJA have osteoarthritis (OA), ∼3–5% have rheumatoid arthritis (RA). For patients with RA, it is not known whether the protective benefit of high surgeon TJA volume applies, or whether specific surgical experience in patients with RA is required.
RA differs from OA in terms of pathogenesis, prognosis, and medical management ([6, 7]). We recently showed that patients with RA who undergo TJA are at a higher risk of early surgical complications relative to patients with OA ([8, 9]). These findings are not surprising, because TJA in patients with RA may pose unique surgical challenges. Relative to patients with OA, patients with RA have, on average, more severe synovitis ([10, 11]), more delicate soft tissue ([12-14]), weaker tendons (), weaker ligaments ([10, 11]), and weaker bone–tendon attachments ([16, 17]). Patients with RA are also more likely to have osteopenia ([18-20]) and periarticular bone changes ([21-24]). These anatomic differences have implications for soft tissue handling, joint alignment, implant fixation, and successful joint mechanics following TJA. The particular challenges in this subgroup of patients may require specific experience on the part of the surgeon.
We sought to determine whether surgeon experience performing TJA in patients with RA is associated with a lower risk of complications following TJA, after controlling for overall TJA surgeon experience and hospital TJA volume. Specifically, the goals of our study were as follows: to determine the correlation between annual overall surgeon volume (i.e., “all TJA”) and annual surgeon volume specifically in patients with RA (i.e., “RA TJA”); to determine the proportion of RA patients who underwent TJA and received their surgery at a teaching hospital; and to determine the impact of surgeon RA TJA volume on the risk of a surgical complication within 2 years of TJA in patients with RA. We hypothesized that 1) increased surgeon RA TJA volume would be highly correlated with surgeon all TJA volume; 2) most RA patients who underwent TJA will have received their surgery from a surgeon with high all TJA volume and at a teaching hospital; and 3) controlling for other factors, increased surgeon RA TJA volume would independently predict a lower risk of complications.
PATIENTS AND METHODS
In this retrospective cohort study, health administrative databases from Ontario, Canada (the most populous province in the country, with a population of 13.5 million in 2012) were used. Ontarians are insured under a single-payer system, which covers all medically necessary procedures, including TJAs. The main data sources were hospital discharge abstracts from the Canadian Institute for Health Information Discharge Abstract Database (CIHI-DAD), and physician claims from the Ontario Health Insurance Plan (OHIP). These data sets were held securely in a linked, de-identified form and analyzed at the Institute for Clinical Evaluative Sciences. Using specific procedure and diagnostic codes from the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Canada, and the Canadian Classification of Health Interventions (ICD-10-CA/CCI), we created a cohort of patients with RA who underwent elective primary hip TJA or knee TJA (1.VA.53 and 1.VG.53, respectively), with the index procedure occurring between April 1, 2002 and March 31, 2009.
The diagnosis of RA was established using the following validated algorithm: a hospitalization with a diagnosis code for RA or 3 physician-billing claims with a diagnosis code for RA in a 2-year period, with at least 1 claim by a specialist (rheumatologist, orthopedic surgeon, or internist) (sensitivity 78%, specificity 100%) (). We excluded the records of patients for whom the index procedure was not elective and those in whom the procedure was performed secondary to trauma, fracture, or cancer. We also excluded those with a history of joint infection or revision arthroplasty and those who were receiving nursing care immediately prior to surgery or for whom the operating surgeon could not be identified (Figure 1). If a patient underwent multiple procedures, only the first procedure performed during the study period was included.
All patients were followed up from the date of their index TJA until the occurrence of a composite outcome of surgical complication (infection, dislocation, periprosthetic fracture, or revision). Patients were censored after 2 years of followup if they were still event free, or at the time of death, whichever came first. Dislocations were defined by a diagnostic code for dislocation or a procedure code for closed/open reduction. To maximize sensitivity, we identified infections as 1 or more of the following: an ICD-10-CA diagnostic code for intraarticular infection, with a confirmatory code for an irrigation and debridement; a physician claim for a spacer insertion; or a procedure code for a peripheral intravenous central catheter line after the TJA, when the referring physician was an orthopedic surgeon. Periprosthetic fractures were defined by a diagnostic code for fracture following insertion of an implant. Revision procedures were identified using ICD-10-CA/CCI procedure codes accompanied by the supplementary status attribute “R.”
Surgeon all TJA and RA TJA volume
For each TJA, annual surgeon all TJA volume was defined as the number of hip and knee arthroplasty procedures (both primary and revision) performed by the surgeon in the 365 days prior to the procedure (regardless of whether or not the patient had RA), while surgeon RA TJA volume was defined as the number of TJA procedures the surgeon had performed on patients with RA over the same time period. The physician claims differentiate between the surgeon who performed the surgery (the primary surgeon) and the assisting physician (if any). Because the primary surgeon typically makes the key decisions regarding surgical approach, choice of implant, and degree of soft tissue tension, our definition of surgeon volume included primary TJAs for which the surgeon acted as the primary surgeon.
Patient and hospital covariates
Patient and provider factors that have previously been shown to affect the risk of complications following joint replacement were assessed as follows: relevant patient demographic information was obtained from the OHIP Registered Persons Databases (age, sex, neighborhood income quintile, and rurality) ([26-28]); comorbidities listed on hospital discharge abstracts in the 3 years before the index TJA admission were categorized according to an adaptation of the Charlson Comorbidity Index (); Adjusted Clinical Groups, based on diagnosis codes from hospitalizations and physician visits in the 2 years before the index TJA admission were used to classify TJA recipients as “frail” (yes/no) at the time of the index procedure (); and the number of times each TJA recipient had seen a rheumatologist in the 2 years prior to the index TJA () was assessed as a proxy for RA severity. For each patient, the occurrence of a primary TJA before April 1, 2002 (pre-baseline) was identified from the CIHI-DAD using the appropriate ICD-9 procedure codes (for THA, 93.51 and 93.59; for TKA, 93.41). Hospital TJA volume was defined as the number of primary and revision TJA procedures performed at the hospital in the 365 days prior to the index procedure in the RA patient. Teaching hospitals were defined as those that were members of the Council of Academic Hospitals of Ontario (www.caho-hospitals.com).
Spearman's rank correlation coefficients were used to quantify the association between surgeon RA TJA volume and surgeon all TJA volume and hospital TJA volume. Because surgeon volume was defined as the number of procedures performed in the year prior to the index procedure and thus might vary between TJA procedures performed by the same surgeon at different time points in the study period, we used the TJA procedure (and not the surgeon) as the unit of analysis in these correlation analyses.
Distribution of providers
When determining the proportion of RA patients in whom TJA was performed by high-volume surgeons, we dichotomized surgeon all TJA volume and RA TJA volume. We elected to set the threshold for high surgeon all TJA volume at 100 cases/year (high 100+, low <100), based on a recent systematic review that classified high volumes as >50 TKA procedures per year (). In the absence of prior studies examining surgeon RA TJA volume, we defined high surgeon RA TJA volume as the median value or higher and low surgeon RA TJA volume as below the median value. Standardized complication rates (standardized for age, sex, and the joint being replaced) were determined for each surgeon volume category (low all TJA volume and low RA TJA volume; high all TJA volume and low RA TJA volume; low all TJA volume and high RA TJA volume; and high all TJA volume and high RA TJA volume), using indirect standardization.
Impact of surgeon volume on occurrence of complications
Univariate Cox proportional hazards regression models were used to determine the relationship between each covariate and the risk of complications. In these analyses, patients were censored at the time of death. A multivariable Cox proportional hazards model was used to determine the relationship between surgeon RA TJA volume (as a continuous variable) and the risk of a surgical complication after adjusting for relevant confounders. As described above, patients were censored at the time of death if it occurred prior to the occurrence of the composite outcome. A robust sandwich-type variance estimator was used to account for the clustering of patients within the surgeon performing the procedure. Restricted cubic splines were used to allow for a nonlinear relationship between surgeon RA TJA volume and the log-hazard of a complication. Although patient age and sex at the time of surgery were included in the multivariable model a priori, additional covariates were controlled for if, in the univariate regression, they were associated with the composite outcome at a P value of ≤0.4. The additional covariates considered were number of visits to a rheumatologist in the 2 years before the index TJA, neighborhood income quintile, rurality, Charlson Comorbidity Index, frailty, surgeon all TJA volume, and hospital TJA volume (both as continuous variables). We also examined whether there were interactions between surgeon RA TJA volume and individual surgeon volume (dichotomized as high or low) and performance of the TJA at a teaching hospital. All analyses were performed at the Institute for Clinical Evaluative Sciences (www.ices.on.ca) using SAS version 9.3 for UNIX. The probability of a Type I error was set to 0.05 for all analyses.
Between April 1, 2002 and March 31, 2009, a total of 7,472 TJAs (2,814 THAs and 4,658 TKAs) were performed in patients with RA in Ontario, Canada (Figure 1); of these, 4,762 were eligible elective primary TJA procedures (1,515 THAs and 3,247 TKAs) (Table 1). The median age of RA patients eligible for TJA was 66 years (interquartile range [IQR] 57–74 years); most were female (75.3%), with a Charlson score of 0 (78.3%), and only 8.2% were classified as frail.
|Age, median (IQR) years||66 (57–74)|
|Prior TJA, before 2002||1,169 (24.5)|
|Joint replaced, index procedure|
|Saw a rheumatologist in the 2 years prior to the surgery||2,366 (49.7)|
|No. of visits to a rheumatologist in the 2 years prior to surgery, median (IQR)||5 (0–13)|
|Teaching hospital||1,894 (39.8)|
|Surgeon all TJA volume, median (IQR)||130 (86–200)|
|High volume (>100 cases/year)||3,329 (69.9)|
|Surgeon RA TJA volume, median (IQR)||10 (6–19)|
|High volume (>10 cases/year)||2,607 (54.7)|
|Hospital TJA volume, median (IQR)||549 (370–824)|
|Complications within 2 years of index TJA|
|Periprosthetic fracture||43 (0.9)|
|Any complication||152 (3.2)|
Surgeon and hospital characteristics
The 4,762 eligible elective primary TJAs were performed by 423 orthopedic surgeons in 65 hospitals. In ∼84% of the surgeries, the primary surgeon had an assistant; 68% of these assistants were general practitioners, 17% were orthopedic surgeons, and the remainder was a mix of general surgeons and other assorted surgical specialists. Approximately 40% of these procedures were performed in teaching hospitals. The median surgeon all TJA and RA TJA volumes were 130 cases (IQR 86–200) and 10 cases (IQR 6–19), respectively. The median hospital TJA volume was 549 cases (IQR 370–824). Surgeon all TJA volume was significantly correlated with the RA TJA volume (Spearman's rank correlation coefficient 0.76, P < 0.0001) (Figure 2), while the correlation between surgeon RA TJA volume and hospital TJA volume was 0.41 (P < 0.0001). Approximately two-thirds of the RA patients who underwent TJA received their surgery from a surgeon with high all TJA volumes, as we defined it; among the one-third of RA patients who received their TJA from a low-volume surgeon, the majority (72%) also received their TJA from a surgeon with a low RA TJA volume. A small cluster of surgeons (∼5% of those for RA patients undergoing TJA) had low overall TJA volumes but high numbers of TJAs among patients with RA (up to >70 in the previous year).
Surgical complications within 2 years of TJA
Among the 4,762 patients with RA who underwent TJA, 152 (3.2%) experienced at least 1 surgical complication within 2 years of their index TJA. These complications included 42 dislocations (0.9%), 53 infections (1.1%), 43 periprosthetic fractures (0.9%), and 52 revisions (1.1%) (Table 1). The 152 procedures that had a surgical complication were performed by 105 surgeons. The highest number of complications for a single surgeon was 6 (among 79 procedures performed by this surgeon in patients with RA over the study period). Most surgeons (91 of 105) had 1–2 complications over the study period. The age- and sex-standardized rates of complications ranged from a low of 2.76 per 100 cases (RA patients whose surgeons had low all TJA volumes but high RA TJA volumes) to a high of 3.41 per 100 cases (RA patients whose surgeons had high all TJA volumes but low RA TJA volumes) (Table 2).
|RA TJA volume, rate (95% CI)|
|<10 cases/year||≥10 cases/year|
|All TJA volume, rate (95% CI)|
|<100 cases/year||3.21 (2.31–4.36)||2.76 (1.11–5.68)|
|≥100 cases/year||3.41 (2.33–4.81)||2.93 (2.30–3.69)|
Restricted cubic splines demonstrated an approximately linear relationship between surgeon RA TJA volume and the log-hazard of a complication (Figure 3). Consequently, we modified the regression model so that a linear term was used to relate surgeon RA TJA volume to the log-hazard of a complication (thereby allowing us to report a uniform hazard ratio [HR]). In univariate analysis, there was an increased risk of complications if the index procedure was a hip replacement (unadjusted HR 3.47, 95% confidence interval [95% CI] 2.45–4.90, P < 0.0001 [using the index replacement as reference]), if the patient was frail (unadjusted HR 1.81, 95% CI 1.15–2.86, P = 0.01), and if the patient had a Charlson comorbidity score of ≥2 (unadjusted HR 1.73, 95% CI 1.02–2.93, P = 0.04). We did not observe a significant interaction between surgeon RA TJA volume and surgeon all TJA volume (dichotomized as high or low; P = 0.42) or performance of the procedure at a teaching hospital (P = 0.95).
After controlling for significant covariates as well as age, sex, neighborhood income quintile, and occurrence of the procedure at a teaching hospital, surgeon RA TJA volume was independently and significantly associated with a reduced risk of our composite outcome (adjusted HR 0.81 per 10 cases, 95% CI 0.71–0.93, P = 0.002) (Table 3). Collectively, these variables explained 41% of the variance in the outcome (). Further adjustment for surgeon all TJA volume slightly attenuated the effect of surgeon RA TJA volume, but the latter remained statistically significant (adjusted HR 0.84 per additional 10 RA TJA cases, 95% CI 0.69–0.95, P = 0.009), and no independent effect was seen for all TJA volume (adjusted HR 1.00 per additional 10 TJA cases, irrespective of diagnosis, 95% CI 0.98–1.03, P = 0.78). Removal of surgeon RA TJA volume did not result in a significant association between surgeon all TJA volume and the occurrence of a complication (adjusted HR 0.98 per additional 10 TJA cases, 95% CI 0.97–1.00, P = 0.09).
|Univariate analysis||Multivariate analysis|
|Unadjusted HR (95% CI)||P||Adjusted HR (95% CI)||P|
|Age, per year||0.99 (0.98–1.01)||0.22||0.99 (0.98–1.01)||0.39|
|Male||0.92 (0.63–1.35)||0.67||0.89 (0.68–1.31)||0.54|
|Lowest||1.17 (0.72–1.90)||0.53||1.22 (0.76–1.97)||0.42|
|2||0.85 (0.53–1.38)||0.52||0.88 (0.54–1.43)||0.61|
|3||0.71 (0.40–1.25)||0.24||0.72 (0.42–1.25)||0.25|
|4||0.98 (0.59–1.62)||0.95||0.95 (0.57–1.57)||0.83|
|Prior TJA, before 2002||1.07 (0.75–1.54)||0.69|
|Joint replaced, index procedure|
|THA||3.47 (2.45–4.90)||<0.0001||3.42 (2.41–4.86)||<0.0001|
|No. of visits to a rheumatologist in the 2 years prior to surgery, per visit||1.01 (0.99–1.02)||0.20||1.01 (0.99–1.02)||0.19|
|Frail||1.81 (1.15–2.86)||0.01||1.83 (1.19–2.79)||0.006|
|1||1.10 (0.68–1.79)||0.70||0.99 (0.62–1.59)||0.97|
|≥2||1.73 (1.02–2.93)||0.04||1.49 (0.86–2.57)||0.16|
|Teaching hospital||1.20 (0.85–1.68)||0.29||1.34 (0.95–1.91)||0.09|
|Surgeon all TJA volume, per 10 cases||0.99 (0.98–1.01)||0.46|
|Hospital TJA volume, per 50 cases||1.01 (0.98–1.03)||0.64|
|Surgeon RA TJA volume, per 10 cases||0.89 (0.79–1.01)||0.06||0.81 (0.71–0.93)||0.002|
In a cohort of patients with RA undergoing elective primary TJA of the hip or knee, and taking into consideration previously identified predictors of complications following TJA, we observed that greater surgeon experience performing TJA in patients with RA was independently and significantly associated with reduced risk of early surgical complications. This relationship appeared to be linear, and no threshold or cut point for surgeon RA TJA volume was identified. Approximately 3.2% of the patients in our cohort experienced a complication within 2 years of their TJA; this risk declined by ∼20% for every 10 additional RA TJA procedures performed by the surgeon in the year prior to the surgery.
Although surgeons who performed more TJAs overall were also more likely to have some experience performing TJA in patients with RA, we did not observe an independently significant protective benefit of overall surgeon experience once we accounted for experience performing TJA in patients with RA. These findings indicate that specific experience performing TJA in patients with RA is required to adequately prepare surgeons for their associated operative challenges ([14, 19, 34-39]). To our knowledge, this study is the first to demonstrate that surgeon experience in patients with RA has a protective benefit for TJA recipients with RA.
Because the performance of TJA in patients with RA poses unique challenges, both intraoperatively ([10-24]) and perioperatively ([40-42]), we hypothesized that most patients with RA would receive TJA in high-volume teaching hospitals, but this was not the case; only ∼40% of our TJA recipients with RA received their surgery at an academic center. We also hypothesized that due to the added complexity of performing TJA in patients with RA versus patients with OA, most RA patients receiving TJA would have the procedure performed by a high-volume surgeons. Indeed, two-thirds of our patients received their surgery from a high-volume surgeon. However, we identified a small but distinct group of patients who received their TJA from surgeons who were experts in performing the procedure in patients with RA; the latter appeared to perform TJA predominantly in patients with RA. Patients with RA who received their TJA from an expert had the lowest risk of surgical complications. These findings provide further support for the importance of RA patient–specific surgical expertise in ensuring optimal surgical outcomes.
In prior work, we have shown that, among patients with RA undergoing TJA, the rate of complications is higher for total hip replacement versus total knee replacement (). Unfortunately, the relatively small number of RA patients receiving a TJA who experienced a complication precluded analyses of the effect of surgeon RA TJA volume on the risk of complications following hip replacement versus knee replacement in patients with RA. The relatively small number of complications also precluded an analysis of specific complications (e.g., dislocation following THA), and as such we cannot comment on whether the effect of surgeon RA TJA volume varies according to complication. Further research in larger samples is warranted to address these issues.
The algorithm used to define the presence or absence of RA has high specificity and sensitivity but does not provide information on disease severity (). We controlled for possible proxy measures of RA severity, including frailty () and the number of visits to a rheumatologist in the 2 years prior to surgery (). Although frailty is associated with more severe underlying disease, an increased frequency of visits to a rheumatologist may not necessarily indicate increased severity but rather may indicate appropriate preoperative management of RA, which may contribute to improved outcomes postoperatively. As such, we cannot rule out the possibility that systematic differences in the types of RA patients in whom surgeons perform TJA explain our findings. However, because patients with more severe RA would likely be deemed at higher risk of complications following TJA compared with those with stable disease, one might expect that these patients would preferentially be operated on by more experienced surgeons. If so, more complete adjustment for RA severity may serve to accentuate the effect of surgeon RA TJA experience on surgical outcomes. Further research is needed to test this hypothesis.
Our definition of surgeon TJA volume was based on the number of procedures performed by the surgeon in the 365 days immediately preceding each surgery. A similar definition has been used in previous studies ([5, 45]). Alternatively, some studies have defined surgeon volume as the average caseload for a surgeon over a period of time. While this allows for a uniform volume for each surgeon, it also assumes that current experience will benefit future cases, which may not be the case, especially if a surgeon's volume changes over time. The advantage of the surgeon volume definition used in the current study is that it allows for fluctuations in a surgeon's caseload over time (i.e., from early to later in his or her career). Furthermore, this definition does not assume that a benefit necessarily derives from a surgeon's years in practice; rather, it evaluates his or her specific recent experience performing TJAs.
The strengths of our study include the use of population-based health administrative data to assemble a large sample of RA patients who received TJA, defined using a validated algorithm for RA, and consideration of patient, hospital, and surgeon predictors of post-TJA complications. However, there were some limitations in addition to those already noted. First, we did not have any information on patient-reported outcomes, including post-TJA pain, functioning, and improvements in quality of life. Thus, we do not know whether surgeon experience is also predictive of these outcomes ([1, 45]). However, because the occurrence of surgical complications has been linked with worse patient-reported outcomes ([46, 47]), it is likely that greater surgeon experience with RA also contributes to improved patient-reported outcomes in this population. Second, we were unable to capture and thus adjust for technical aspects of the procedure, e.g., surgical approach (), implant type (), and use of bone cement (), which have been associated with complication rates following TJA. Surgeons with greater experience performing TJA in patients with RA may systematically differ from those with less experience with respect to surgical techniques; if so, this may account, at least in part, for the RA TJA volume effect. Further research is recommended to confirm or refute these hypotheses.
In summary, among patients with RA who underwent elective primary TJA of the hip or knee, those who were operated on by surgeons who performed a greater number of these procedures in patients with RA experienced fewer complications, after controlling for relevant confounders including overall TJA experience. Our findings indicate that overall experience performing TJA is insufficient with respect to optimizing outcomes for patients with RA undergoing this procedure. This has implications for specialty training, because surgeons who want to establish a practice in patients with RA may benefit from specialized training. These findings are also relevant to referring physicians, who should not assume that high-volume surgeons necessarily have the requisite experience in patients with RA.
All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published. Dr. Ravi had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study conception and design. Ravi, Croxford, Hollands, Paterson, Bogoch, Kreder, Hawker.
Acquisition of data. Ravi, Hollands.
Analysis and interpretation of data. Ravi, Croxford, Austin, Paterson, Hawker.
- 3Provider volumes and early outcomes of primary total joint replacement in Ontario.Can J Surg2010;53:175–83., , , , , , et al.
- 6Centers for Disease Control and Prevention. Rheumatoid arthritis. URL: http://www.cdc.gov/arthritis/basics/rheumatoid.htm.
- 7Epidemiology of rheumatic diseases [review].Rheumatology (Oxford)2000;39 Suppl 2:3–12..
- 10Bone destruction in arthritis [review].Ann Rheum Dis2002;61 Suppl 2:ii84–6..
- 14Production of cytokines, vascular endothelial growth factor, matrix metalloproteinases, and tissue inhibitor of metalloproteinases 1 by tenosynovium demonstrates its potential for tendon destruction in rheumatoid arthritis.Arthritis Rheum2001;44:1754–60., , , , .
- 17Distinct topography of erosion and new bone formation in Achilles tendon enthesitis: implications for understanding the link between inflammation and bone formation in spondylarthritis.Arthritis Rheum2008;58:2694–9., , , , , , et al.
- 21Protrusio acetabuli in rheumatoid arthritis.Clin Orthop Relat Res1975;108:76–83., .
- 25Accuracy of Canadian health administrative databases in identifying patients with rheumatoid arthritis: a validation study using the medical records of rheumatologists.Arthritis Care Res (Hoboken)2013;65:1582–91., , , , , , et al.
- 28Measuring “rurality” for purposes of health-care planning: an empirical measure for Ontario.Toronto:Ontario Medical Association;2005..
- 30The Johns Hopkins ACG System: technical reference guide version 10.0.Baltimore:Johns Hopkins University Bloomberg School of Public Health;2011., .
- 36Total knee arthroplasty in patients with rheumatoid arthritis: an overview.Clin Orthop Relat Res1999;366:54–60., .
- 37Extensor mechanism repair failure with use of bidirectional barbed suture in total knee arthroplasty.J Arthroplasty2012;27:1413.e1–4., , , , , .
- 45Association of hospital and surgeon procedure volume with patient-centered outcomes of total knee replacement in a population-based cohort of patients age 65 years and older.Arthritis Rheum2007;56:568–74., , , , , , et al.
- 48Surgical approach, abductor function, and total hip arthroplasty dislocation.Clin Orthop Relat Res2002;405:46–53., .