Association between hospital procedure volume and risk of revision after total hip arthroplasty: a population-based study within the Nordic Arthroplasty Register Association database

Why do Primary Total Hip Arthroplasties Fail in Patients Under 65 Years of Age? A Systematic Review and Meta-Analysis

INTRODUCTION

Primary total hip arthroplasties (THAs) are increasing among patients under 65 years of age. Hence, there is a need to elucidate implant survivorship and etiologies of revision THA. The purpose of this systematic review was to identify (1) implant survivorship and (2) the most common etiologies for failure of primary THA in patients under 65 years of age.

METHODS

A comprehensive search of four major databases was performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in selecting studies, data extraction, and analysis. There were 11 studies selected from a total of 574 studies from searches.

RESULTS

There was a revision rate of 4.5% (n = 2,811 revisions) with substantial publication bias (P = 0.03) and heterogeneity among studies (I2 = 88%; P = 0.0001). The implant survivorships at five, 10, and 15 years were 96% (n = 59,440), 92% (n = 1,338), and 84% (n = 788 hips), respectively. The most common etiology for revision was infection with no publication bias (P = 0.6) and substantial heterogeneity (I2 = 99%; P = 0.0001).

CONCLUSION

This review showed high implant survivorships up to 15 years in patients under 65 years of age. There are multiple confounders that were not controlled for in this study, and future studies should focus on evaluating patient- and surgery-specific factors that could influence implant survivorship.

The relationship between surgeon case load and revision rates in total hip arthroplasty: Evidence from the Swiss National Joint Registry

STUDY AIMS

Higher surgeon volume has been correlated with improved therapy outcomes following total hip arthroplasty, and many countries have implemented minimum volume standards as a precondition for claiming reimbursement. However, there are large differences between healthcare systems worldwide and the applicability of international studies to a particular local healthcare environment may be limited. The aim of this study was to assess the relationship between surgeon case load (= number of procedures per year) and short-term revision rates (within two years of the index procedure) in patients undergoing primary total hip arthroplasty for hip osteoarthritis in a nationwide, registry-based study. In addition, the effects of increasing minimum volume standard thresholds on the potential reduction of the revision burden was simulated.

METHODS

All patients registered in the Swiss National Joint Registry (SIRIS) for undergoing primary total hip arthroplasty for hip osteoarthritis between 2015 and 2021 were considered. Patients were aggregated according to the lead surgeon's individual code. Surgeons lacking five years of uninterrupted practice were excluded. Multiple logistic and bivariate multinomial regressions were employed to model the odds of revision surgery (overall and for specific diagnoses) as a function of surgeon case load. Two-year revision rates, the proportional reduction of the revision burden and the number of patients hypothetically needing treatment reassignment to higher-volume surgeons were simulated for increasing minimum volume standard thresholds.

RESULTS

In total, 74,565 total hip arthroplasty procedures performed by 384 surgeons were assessed. The mean surgeon case load was 28.7 total hip arthroplasties / year (min/max: 1.8/269.1; median: 18.1). The average overall 2-year revision rate in the observation period was 2.25%. A higher surgeon case load was associated with lower cumulative revision rates (revision for any reason, and revision due to infection, dislocation and femoral periprosthetic fracture). Overall revision rates of surgeons with a minimal case load of up to 10 / 20 / 50 total hip arthroplasties / year were 2.18% / 2.01 % / 1.70%, respectively. Implementation of a minimum volume standard of 10 / 20 / 50 total hip arthroplasties / year would reduce the overall 2-year revision rates by 3.2%, 10.5% and 23.8%, respectively, but also require that 5.1%, 18.1% and 53.8% of patients be reassigned to higher-volume surgeons instead of initially intended lower volume surgeons.

CONCLUSION

A higher surgeon case load independently predicts a lower overall 2-year revision rate in patients undergoing primary total hip arthroplasty for hip osteoarthritis in Switzerland. Implementation of a minimal case load has the potential to significantly reduce 2-year revision rates, at the cost of more patients needing to have their treatment reassigned.

Impact of Hospital Case Volume on the Complication Rate in Hip Arthroplasty: An Analysis of Nationwide AOK Data

Aufgrund des demografischen Wandels und damit verbundener erwarteter Steigerungen der Fallzahlen von primärer Hüftendoprothetik und Revisionseingriffen ist es wichtig, Faktoren zu identifizieren, die Komplikationen und Revisionen reduzieren können. Ein solcher Faktor ist die Fallzahl eines Krankenhauses. Studien haben gezeigt, dass Krankenhäuser mit höheren Fallzahlen niedrigere Morbiditäts- und Komplikationsraten aufweisen. Die meisten Studien basieren dabei auf Registerdaten, die oft unvollständig sind und keine patientenspezifischen Faktoren beinhalten.In dieser Studie wurden bundesweite pseudonymisierte stationäre Abrechnungsdaten und Versichertenstammdaten der Allgemeinen Ortskrankenkassen (AOK) im Zeitraum von 2017 bis 2019 bei Patienten mit primärer Hüftendoprothese analysiert. Zur Analyse des Einflusses der Fallzahl auf das Outcome wurden 5 Fallzahlkategorien gebildet (I: 1-49, II: 50-99, III: 100-199, IV: 200-399, V: ≥ 400 Operationen pro Jahr). Als Endpunkte wurden 90-Tage-Sterblichkeit, 1-Jahres-Revisionsoperationen, chirurgische Komplikationen (90 Tage bzw. 365 Tage), periprothetische Femurfrakturen (90 Tage) und schwere Allgemeinkomplikationen im Krankenhausaufenthalt betrachtet. Der Einfluss der Fallzahl auf das Outcome wurde mittels multipler logistischer Regression unter Berücksichtigung patientenspezifischer Faktoren bestimmt.Die Analyse von 137494 Fällen aus 993 Kliniken zeigt einen statistisch signifikanten Zusammenhang zwischen der Fallzahlgruppe und der Häufigkeit von Revisionsoperationen, chirurgischen Komplikationen, periprothetischen Femurfrakturen und allgemeinen Komplikationen. Bei Kliniken mit einer Fallzahl von weniger als 50 pro Jahr zeigte sich eine Risikoerhöhung um 65%-88% für diese Endpunkte gegenüber der fallzahlstärksten Gruppe. Für den Endpunkt Sterblichkeit ergibt eine dichotome Betrachtung der Fallkategorien ebenfalls einen signifikanten Einfluss der Fallzahlen.Die Studie zeigt, dass, auch unter Berücksichtigung patientenspezifischer Faktoren, höhere Fallzahlen bei primärer Hüftendoprothetik in Krankenhäusern mit niedrigeren Komplikationsraten verbunden sind. Diese Erkenntnisse unterstreichen die Bedeutung der Fallzahl als Faktor zur Verbesserung der Versorgungsqualität in der Hüftendoprothetik.

The changing effect of surgeon volume on revision rates in shoulder arthroplasty with time in Australia

BACKGROUND

The concept that surgical volume affects rates of total primary shoulder arthroplasty (TSA) revision is widely accepted. The aim of this study was to determine if surgical volume is confounded by patient, implant, and institutional factors and time since TSA.

METHODS

Using data from a large national arthroplasty registry for the period January 1, 2008, to December 31, 2022, all interactions with orthopedic surgeon volume (SV) undertaking primary TSA procedures for all diagnoses were examined. A subanalysis from January 1, 2017, provided a contemporary analysis with additional patient demographics. The primary outcome measure was the cumulative percentage revision (CPR), which was defined using Kaplan-Meier estimates of survivorship and hazard ratios from Cox proportional hazard models with a multivariable adjustment.

RESULTS

The incidence of orthopedic surgeons completing TSA increased nationally from 0.9 per 100,000 population in 2008 to 1.8 in 2022. Of 55,605 TSA procedures, the CPR at 11 years varied from 8.8% (95% confidence interval [CI] 8.0, 9.6) to 5.6% (95% CI 4.0, 7.7) for implants by surgeons with SV <10 per annum and for prostheses by SV >35 per annum, respectively. Instability or dislocation was the most common reason for revision. SV had a significant effect on the revision rate for all diagnoses (P = .001), instability or dislocation (P = .018), and revision within 5 years of primary arthroplasty (P = .011). In contrast, at subanalysis (last 5 years), there was no interaction both with main effects (SV effect adjusted by age and gender) and with an extended adjustment for both instability or dislocation and all-cause revision.

CONCLUSIONS

Nationally there is an increasing incidence of primary TSA procedures and surgeons performing them. The association between SV and revision rate is complex. Although there is an association with main effects, there was no association in the past 5 years. Reduction in instability or dislocation revision rates contributed to this change. Patient, implant, or institutional factors did not confound analysis of SV on primary TSA revision rates but recency did.

Short-term outcomes with routine use of size ≥40 femoral heads in THA: A retrospective cohort study

Background

Using larger femoral heads during total hip arthroplasty (THA) may result in a more stable hip. Greater volumetric wear and frictional torque, however, may result in increased postoperative complications. The purpose of this study was to compare outcomes of patients with femoral head size ≥40 mm compared to those with femoral head size <40 mm.

Materials and methods

A retrospective chart review of 504 THAs performed by a single surgeon at a single institution from 2009 to 2016 was conducted. Following exclusions, 131 THAs were identified with femoral heads ≥40 mm and 348 THAs were identified with femoral heads <40 mm. In addition to demographic data, all postoperative complications were recorded. Plain radiographs were used to rule out/in periprosthetic osteolysis and/or acetabular loosening. Chi-square tests and Student's t-tests were used to compare categorical and continuous variables, respectively.

Results

Mean follow-up period for the entire cohort was 5.5 years. Complications with ≥40 mm femoral heads included 1 superficial infection and 1 deep periprosthetic joint infection (PJI). There were no cases of dislocation, osteolysis, acetabular loosening, or trunnionosis. In contrast, complications with <40 mm femoral heads included 9 dislocations and 7 PJIs.

Conclusion

The routine use of large femoral heads (≥40-mm) during THA appears to be a safe option for patients at short-term clinical follow-up. Notably, 0 patients had a clinical course complicated by dislocation, osteolysis, acetabular loosening, or trunnionosis.

Level of evidence

Level III Retrospective Cohort Study.

Statistical models and implant customization in hip arthroplasty: Seeking patient satisfaction through design

Objectives

This study conducts a systematic literature review to explore the role of statistical models and methods in the design of orthopedic implants, with a specific focus on hip arthroplasty. Through a comprehensive analysis of the scientific literature, it aims to understand the relevance and applicability of these models in implant development and research trends in the field of design.

Methods

Data analysis and co-occurrence mapping techniques were employed to investigate the statistical models used as predictors of satisfaction in hip arthroplasty and in implant design. This approach facilitated a detailed and objective assessment of existing literature, revealing key trends and identifying gaps in current knowledge.

Key findings

The review's findings underscore a burgeoning interest in implant customization, with a significant emphasis on leveraging statistical techniques for optimal design. The logistic model methodology was applied to analyze a survey of hip surgery specialists, revealing that the physician's age does not influence the decision to use a customized implant. Furthermore, the review highlighted a knowledge gap at the intersection of statistics and design discipline concerning implant customization.

Significance

Despite the recognized importance of customization in implant design, there remains a dearth of contributions from the design discipline perspective in the existing literature, indicating substantial room for improvement and the need for interdisciplinary integration.

Conclusion

The integration of statistical methods in implant design is crucial, emphasizing the need for multidisciplinary approaches and customization to enhance patient satisfaction. This study provides a foundation for future research that could transform the field of hip arthroplasty through more personalized and effective solutions.

Risk of early revision in total hip arthroplasty: the relative contribution of the surgeon versus the hospital

BACKGROUND

Early revision for total hip arthroplasty is a serious adverse outcome. There are multiple contributing risk factors for early revision. Risk factors can exist at the level of the surgeon and the level of the institution. The primary research question of this study was to determine the relative contribution of surgeon-level and hospital-level variance to rates of early revision (overall and for infection) after primary total hip arthroplasty.

METHODS

This is a registry-based study from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Data for the most commonly used stem (Exeter V40) were used to reduce prosthesis variation from the analysis. A mixed effects Cox Model (also known as a frailty model) with crossed random effects for surgeon and hospital was used. Outcomes were early revision (within 2 years) for all causes and for infection. This model allowed for the risk of early revision to be explained by the variability at the surgeon level or hospital level.

RESULTS

There were 32 031 procedures performed by 735 surgeons across 250 hospitals between 1 January 2015 and 31 December 2019. Surgeon variability significantly contributed to overall variation in revision for any cause and revision for infection (P < 0.0001). There was no significant contribution of hospital-level variation to overall revision or for infection.

CONCLUSIONS

Surgeon-level factors play a more important role than institution-level factors in early revision after primary total hip arthroplasty. If surgeons are identified as having a higher risk of revision, there is potential for surgeon-level practice change to reduce the risk of early revision.

Registry Data Show Complication Rates and Cost in Revision Hip Arthroplasty

INTRODUCTION

Revision THA (rTHA) places a burden on patients, surgeons, and health care systems because outcomes and costs are less predictable than primary THA. The purposes of this study were to define indications and treatments for rTHA, quantify risk for readmissions and evaluate the economic impacts of rTHA in a hospital system.

METHODS

The arthroplasty database of a hospital system was queried to generate a retrospective cohort of 793 rTHA procedures, performed on 518 patients, from 2017 to 2019 at 27 hospitals. Surgeons performed chart reviews to classify indication and revision procedure. Demographics, lengths of stay (LOS), discharge dispositions, and readmission data were collected. Analyses of direct costs were performed and categorized by revision type.

RESULTS

46.3% of patients presented for infection. Patients presenting for infection were 5.6 times more likely to have repeat rTHA than aseptic patients. Septic cases (4.3 days) had longer LOS than aseptic ones (2.4) (P < 0.0001). 31% of patients discharged to a skilled nursing facility (SNF). Direct costs were greatest for a two-stage exchange ($37,642), and lowest for liner revision ($8,979). Septic revisions ($17,696) cost more than aseptic revisions ($11,204) (P< 0.0001). The 90-day readmission rate was 21.8%. Septic revisions had more readmissions (13.5%) than aseptic revisions (8.3%).

CONCLUSIONS

Hip revisions, especially for infection, have an increased risk profile and create a major economic impact on hospital systems. Surgeons may use these data to counsel patients on risks of rTHA and advocate for improved reimbursement for the care of revision patients.

Treatment strategies for recurrent dislocation following total hip arthroplasty: relationship between cause of dislocation and type of revision surgery

Background

There are many therapeutic options for dislocation following total hip arthroplasty (THA). The aim of this study was to evaluate the results of revision surgery for dislocated hips.

Methods

Between November 2001 and December 2020, 71 consecutive revision hip surgeries were performed at our institution for recurrent dislocation following THA. We conducted a retrospective study of all 65 patients (71 hips), who were followed for a mean of 4.7 ± 3.2 years (range, 1–14). The cohort included 48 women and 17 men, with a mean age of 71 ± 12.3 years (range, 34–92). The mean number of previous surgeries was 1.6 ± 1.1 (range, 1–5). From intraoperative findings, we created six categories of revision hip surgery for recurrent dislocation following THA: open reduction and internal fixation (2 hips); head change or liner change only (6 hips); cup change with increased head size only (14 hips); stem change only (7 hips); cup and stem change (24 hips); and conversion to constrained cup (18 hips). Prosthesis survival was analyzed by the Kaplan-Meier method, with repeat revision surgery for re-dislocation or implant failure as the endpoint. A cox proportional hazards model was used for risk factors of re-revision surgery.

Results

Re-dislocation occurred in 5 hips (7.0%) and implant failure in 1 hip (1.4%). The 10-year survival rate was 81.1% (95% confidence interval, 65.5–96.8). A Dorr classification of “positional” was a risk factor for re-revision surgery due to re-dislocation.

Conclusion

Clear understanding of the cause of dislocation is essential for optimizing revision procedures and improving the rate of successful outcomes.

The potential risk of using historic claims to set bundled payment prices: the case of physical therapy after lower extremity joint replacement

Background

One of the most significant challenges of implementing a multi-provider bundled payment contract is to determine an appropriate, casemix-adjusted total bundle price. The most frequently used approach is to leverage historic care utilization based on claims data. However, those claims data may not accurately reflect appropriate care (e.g. due to supplier induced demand and moral hazard effects). This study aims to examine variation in claims-based costs of post-discharge primary care physical therapy (PT) utilization after total knee and hip arthroplasties (TKA/THA) for osteoarthritis patients.

Methods

This retrospective cohort study used multilevel linear regression analyses to predict the factors that explain the variation in the utilization of post-discharge PT after TKA or THA for osteoarthritis patients, based on the historic (2015–2018) claims data of a large Dutch health insurer. The factors were structured as predisposing, enabling or need factors according to the behavioral model of Andersen.

Results

The 15,309 TKA and 14,325 THA patients included in this study received an average of 20.7 (SD 11.3) and 16.7 (SD 10.1) post-discharge PT sessions, respectively. Results showed that the enabling factor ‘presence of supplementary insurance’ was the strongest predictor for post-discharge PT utilization in both groups (TKA: β = 7.46, SE = 0.498, p-value< 0.001; THA: β = 5.72, SE = 0.515, p-value< 0.001). There were also some statistically significant predisposing and need factors, but their effects were smaller.

Conclusions

This study shows that if enabling factors (such as supplementary insurance coverage or co-payments) are not taken into account in risk-adjustment of the bundle price, they may cause historic claims-based pricing methods to over- or underestimate appropriate post-discharge primary care PT use, which would result in a bundle price that is either too high or too low. Not adjusting bundle prices for all relevant casemix factors is a risk because it can hamper the successful implementation of bundled payment contracts and the desired changes in care delivery it aims to support.

A Retrospective Review of Reimbursement in Revision Total Hip Arthroplasty: A Disparity Between Case Complexity and RVU Compensation

BACKGROUND

Revision total hip arthroplasties (THA) are time-consuming, expensive, and technically challenging. Today's Current Procedural Terminology (CPT) codes and relative value units (RVU) may in fact disincentivize surgeons to perform revision THAs. Our study reviewed labor and time investments for each component-specific revision THA and analyzed the gap between procedural value billed and final reimbursement.

METHODS

A retrospective review of 165 primary and revision THAs were validated using operative notes and billing records. We stratified revision THAs by standard CPT coding (with modifiers) as single acetabular component, single femoral component, femoral head plus polyethylene liner (head/liner) exchange, all-components, and spacer placement for infection. Operative time, RVUs, total charges, deductions, and final reimbursement data was collected. Mann-Whitney U tests studied final reimbursement per minute vs per RVU in revision and primary THAs.

RESULTS

Our cohort consisted of 27 primary THAs, 26 acetabular component revisions, 32 head/liner exchanges, 26 femoral component revisions, 27 all-component revisions, and 27 spacer placements. Compared to primary THAs, every revision subgroup except for head/liner exchanges were found to reimburse less per minute and all revision subgroups reimbursed less per RVU (P < .05).

CONCLUSION

Physicians face less reimbursement per minute and per RVU for revision THAs. With cuts in reimbursement set forth by Centers for Medicare and Medicaid Services (CMS) and insurers, revisions may be financially unfavorable. This ultimately will lead to an impending access to care problem in the future. Our study supports the need to re-examine the RVU allocation amongst revision THAs and evaluate changes to the Current Procedural Terminology (CPT) coding system.

Revision Risk of Total Hip Arthroplasty With Vitamin E Doped Liners: Results From the Danish Hip Arthroplasty Register

BACKGROUND

Vitamin E-doped cross-linked polyethylene (VEPE) liners were introduced in total hip arthroplasty (THA) to reduce wear and risk of aseptic loosening and liner fracture. We report this nationwide population-based study to investigate the safety of VEPE liners for THA compared to cross-linked annealed or remelted polyethylene (XLPE).

METHODS

We included THAs from The Danish Hip Arthroplasty Register from January 1, 2008 to June 30, 2019, with uncemented cup, VEPE or XLPE liner, and metal or ceramic head. The outcome was revision due to (1) polyethylene-related endpoints (aseptic loosening, granuloma, osteolysis, or liner fractures) and (2) other endpoints.

RESULTS

A total of 110,803 THAs were assessed for eligibility and 53,842 THAs (46,645 patients) were included in the study: 5069 (9.4%) THAs with a VEPE liner and 48,773 (91.6%) with a XLPE liner. Median observation time was 5.48 (interquartile range 3.80-7.15) years for VEPE and 4.85 (interquartile range 2.68-7.76) for XLPE. VEPE had a lower risk of revision for polyethylene-related endpoints compared to XLPE (hazard ratio [HR] 0.60, 95% confidence interval 0.36-0.98) during complete follow-up. THAs with VEPE liners were associated with increased risk of any revision within the first 3 months (HR 1.62, 1.36-1.94), revision recorded as aseptic loosening within 3 months (HR 4.46, 2.26-8.80), and periprosthetic fracture within 3 months (HR 2.57, 1.98, 3.33).

CONCLUSION

VEPE liners had a lower risk of revision due to polyethylene-related endpoints, but a higher risk of all-cause revision within 3 months.

Effects of Hospital and Surgeon Volume on Patient Outcomes After Total Joint Arthroplasty: Reported From the American Joint Replacement Registry

BACKGROUND

The purpose of this study was to evaluate outcomes and complications because it relates to surgeon and hospital volume for patients undergoing primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) using the American Joint Replacement Registry from 2012 to 2017.

METHODS

A retrospective study was conducted on Medicare-eligible cases of primary elective THAs and TKAs reported to the American Joint Replacement Registry database and was linked with the available Centers of Medicaid and Medicare Services claims and the National Death Index data from 2012 to 2017. Surgeon and hospital volume were defined separately based on the median annual number of anatomic-specific total arthroplasty procedures performed on patients of any age per surgeon and per hospital. Values were aggregated into separate surgeon and hospital volume tertile groupings and combined to create pairwise comparison surgeon/hospital volume groupings for hip and knee.

RESULTS

Adjusted multivariable logistic regression analysis found low surgeon/low hospital volume to have the greatest association with all-cause revisions after THA (odds ratio [OR], 1.63, 95% confidence interval [CI], 1.41-1.89, P < 0.0001) and TKA (OR, 1.72, 95% CI, 1.44-2.06, P < 0.0001), early revisions because of periprosthetic joint infection after THA (OR, 2.50, 95% CI, 1.53-3.15, P < 0.0001) and TKA (OR, 2.18, 95% CI, 1.64-2.89, P < 0.0001), risk of early THA instability and dislocation (OR, 2.47, 95% CI, 1.77-3.46, P < 0.0001), and 90-day mortality after THA (OR, 1.72, 95% CI, 1.27-2.35, P = 0.0005) and TKA (OR, 1.47, 95% CI, 1.15-1.86, P = 0.002).

CONCLUSION

Our findings demonstrate considerably greater THA and TKA complications when performed at low-volume hospitals by low-volume surgeons. Given the data from previous literature including this study, a continued push through healthcare policies and healthcare systems is warranted to direct THA and TKA procedures to high-volume centers by high-volume surgeons because of the evident decrease in complications and considerable costs associated with all-cause revisions, periprosthetic joint infection, instability, and 90-day mortality.

LEVEL OF EVIDENCE

III.

Does Hypothetical Centralization of Revision THA and TKA Exacerbate Existing Geographic or Demographic Disparities in Access to Care by Increased Patient Travel Distances or Times? A Large-database Study

BACKGROUND

Higher hospital volume is associated with lower rates of adverse outcomes after revision total joint arthroplasty (TJA). Centralizing revision TJA care to higher-volume hospitals might reduce early complication and readmission rates after revision TJA; however, the effect of centralizing revision TJA care on patient populations who are more likely to experience challenges with access to care is unknown.

QUESTIONS/PURPOSES

(1) Does a hypothetical policy of transferring patients undergoing revision TJA from lower-to higher-volume hospitals increase patient travel distance and time? (2) Does a hypothetical policy of transferring patients undergoing revision TJA from lower- to higher-volume hospitals disproportionately affect travel distance or time in low income, rural, or racial/ethnic minority populations?

METHODS

Using the Medicare Severity Diagnosis Related Groups 466-468, we identified 37,147 patients with inpatient stays undergoing revision TJA from 2008 to 2016 in the Statewide Planning and Research Cooperative System administrative database for New York State. Revisions with missing or out-of-state patient identifiers (3474 of 37,147) or those associated with closed or merged facilities (180 of 37,147) were excluded. We chose this database for our study because of relative advantages to other available databases: comprehensive catchment of all surgical procedures in New York State, regardless of payer; each patient can be followed across episodes of care and hospitals in New York State; and New York State has an excellent cross-section of hospital types for TJA, including rural and urban hospitals, critical access hospitals, and some of the highest-volume centers for TJA in the United States. We divided hospitals into quartiles based on the mean revision TJA volume. Overall, 80% (118 of 147) of hospitals were not for profit, 18% (26 of 147) were government owned, 78% (115 of 147) were located in urban areas, and 48% (70 of 147) had fewer than 200 beds. The mean patient age was 66 years old, 59% (19,888 of 33,493) of patients were females, 79% (26,376 of 33,493) were white, 82% (27,410 of 33,493) were elective admissions, and 56% (18,656 of 33,493) of admissions were from government insurance. Three policy scenarios were evaluated: transferring patients from the lowest 25% by volume hospitals, transferring patients in the lowest 50% by volume hospitals, and transferring patients in the lowest 75% by volume hospitals to the nearest higher-volume institution by distance. Patients who changed hospitals and travelled more than 60 miles or longer than 60 minutes with consideration for average traffic patterns after the policy was enacted were considered adversely affected. The secondary outcome of interest was the impact of the three centralization policies, as defined above, on lower-income, nonwhite, rural versus urban counties, and Hispanic ethnicity.

RESULTS

Transferring patients from the lowest 25% by volume hospitals resulted in only one patient stay that was affected by an increase in travel distance and travel time. Transferring patients from the lowest 50% by volume hospitals resulted in 9% (3050 of 33,493) of patients being transferred, with only 1% (312 of 33,493) of patients affected by either an increased travel distance or travel time. Transferring patients from the lowest 75% by volume hospitals resulted in 28% (9323 of 33,493) of patients being transferred, with 2% (814 of 33,493) of patients affected by either an increased travel distance or travel time. Nonwhite patients were less likely to encounter an increased travel distance or time after being transferred from the lowest 50% by volume hospitals (odds ratio 0.31 [95% CI 0.15 to 0.65]; p = 0.002) or being transferred from the lowest 75% by volume hospitals (OR 0.10 [95% CI 0.07 to 0.15]; p < 0.001) than white patients were. Hispanic patients were more likely to experience increased travel distance or time after being transferred from the lowest 50% by volume hospitals (OR 12.3 [95% CI 5.04 to 30.2]; p < 0.001) and being transferred from the lowest 75% by volume hospitals (OR 3.24 [95% CI 2.24 to 4.68]; p < 0.001) than non-Hispanic patients were. Patients from a county with a lower median income were more likely to experience increased travel distances or time after being transferred from the lowest 50% by volume hospitals (OR 69.5 [95% CI 17.0 to 283]; p < 0.001) and being transferred from the lowest 75% by volume hospitals (OR 3.86 [95% CI 3.21 to 4.64]; p < 0.001) than patients from counties with a higher median income. Patients from rural counties were more likely to be affected after being transferred from the lowest 50% by volume hospitals (OR 98 [95% CI 49.6 to 192.2]; p < 0.001) and being transferred from the lowest 75% by volume hospitals (OR 11.7 [95% CI 9.89 to 14.0]; p < 0.001) than patients from urban counties.

CONCLUSION

Although centralizing revision TJA care to higher-volume institutions in New York State did not appear to increase the travel burden for most patients, policies that centralize revision TJA care will need to be carefully designed to minimize the disproportionate impact on patient populations that already face challenges with access to healthcare. Further studies should examine the feasibility of establishing centers of excellence designations for revision TJA, the effect of best practices adoption by lower volume institutions to improve revision TJA care, and the potential role of care-extending technology such as telemedicine to improve access to care to reduce the effects of travel distances on affected patient populations.

LEVEL OF EVIDENCE

Level III, prognostic study.

Artroplastia de quadril no Sistema Único de Saúde: análise dos óbitos hospitalares no Estado do Rio de Janeiro, Brasil

O envelhecimento populacional traz desafios ao sistema de saúde. O aumento das doenças degenerativas articulares e a ocorrência de quedas podem demandar a realização de artroplastia de quadril. Objetivou-se avaliar os fatores associados a óbitos hospitalares por artroplastia de quadril no Sistema Único de Saúde (SUS), no Estado do Rio de Janeiro, Brasil. Realizou-se um estudo transversal utilizando o Sistema de Informações Hospitalares do SUS, considerando internações e óbitos por artroplastias de quadril ocorridos entre 2016-2018. As análises consideraram as internações por caráter de atendimento (eletivo, urgência e acidentes ou lesão e envenenamento). Realizou-se regressão logística binária para obter a razão de chance de óbito. A mortalidade aumentou conforme a gravidade da internação. A maioria das internações com óbito foi por fratura de fêmur, demandando cuidados intensivos, tempo médio de permanência de 21,5 dias, envolveu mulheres com 80 anos e mais, da raça/cor branca, que realizaram procedimento em unidades habilitadas em alta complexidade em ortopedia e traumatologia, municipais e classificadas como geral II, localizadas na região de moradia do usuário. A chance de óbito se mostrou significativa para a idade do usuário, uso de unidade de terapia intensiva (UTI) e permanência hospitalar. Espera-se aumento da demanda por artroplastias de quadril e reabilitação física com o envelhecimento populacional. As equipes de saúde devem estar preparadas para lidar com uma população envelhecida. Conhecer os fatores que incrementem o risco de óbito favorece o planejamento e o manejo do cuidado pela equipe hospitalar, inclusive no sentido de diminuir a permanência hospitalar, tão impactante na condição funcional de pessoas idosas.

Tranexamic acid use in high-risk blood transfusion patients undergoing total hip replacement: a randomised controlled trial

INTRODUCTION

We hypothesised that a single preoperative intravenous dose of tranexamic acid (TXA) is effective in patients who undergo total hip arthroplasty (THA) and are at high risk of blood transfusion (preoperative haemoglobin level <13.0 g/dL).

METHODS

A prospective, randomised controlled study of 308 patients who underwent primary THA was conducted. 256 participants remained in the study and were divided into 2 major groups: high-risk group comprising 116 patients with preoperative Hb < 13.0 g/dL (57 of whom were treated with a 15 mg/kg intravenous bolus of TXA, and 59 of whom did not receive the medication) and low-risk group comprising 140 patients with Hb ⩾ 13.0 g/dL (71 of whom received the same dose of TXA, and 69 of whom did not). Participants were followed up at 3 weeks, 3 months, 6 months, and 1 year after surgery.

RESULTS

The use of TXA in both groups of patients significantly increased the levels of postoperative Hb and Ht. TXA protected high-risk patients from blood loss and from transfusion. In low-risk patients the use of TXA reduced blood loss but did not protect from blood transfusion. The median length of stay was significantly affected for high-risk patients. No thromboembolic event was recorded in either group.

CONCLUSIONS

TXA reduces intra- and postoperative bleeding, transfusion rates, and the length of hospital stays in patients with low preoperative Hb. The use of TXA in patients with normal preoperative Hb reduces blood loss but does not affect the transfusion rate.ClinicalTrials.gov Identifier: NCT03019198.

Compensation claims after hip arthroplasty surgery in Norway 2008-2018

Background and purpose - Orthopedic surgery is one of the specialties with most compensation claims, therefore we assessed the most common reasons for complaints following total hip arthroplasty (THA) reported to the Norwegian System of Patient Injury Compensation (NPE) and viewed these complaints in light of the data from the Norwegian Arthroplasty Register (NAR).Patients and methods - We collected data from NPE and NAR for the study period (2008-2018), including age, sex, and type of complaint, and reason for accepted claims from NPE, and the number of arthroplasty surgeries from NAR. The institutions were grouped by quartiles into quarters according to annual procedure volume, and the effect of hospital procedure volume on the risk for accepted claim was estimated.Results - 70,327 THAs were reported to NAR. NPE handled 1,350 claims, corresponding to 1.9% of all reported THAs. 595 (44%) claims were accepted, representing 0.8% of all THAs. Hospital-acquired infection was the most common reason for accepted claims (34%), followed by wrong implant position in 11% of patients. Low annual volume institutions (less than 93 THAs per year) had a statistically significant 1.6 times higher proportion of accepted claims compared with higher volume institutions.Interpretation - The 0.8% risk of accepted claims following THAs is 1.6 times higher for patients treated in low-volume institutions, which should consider increasing the volume of THAs or referring these patients to higher volume institutions.

Uncemented or cemented stems in first-time revision total hip replacement? An observational study of 867 patients including assessment of femoral bone defect size

Background and purpose - Uncemented stems are gradually replacing cemented stems in hip revision surgery. We compared the risk of re-revision between uncemented and cemented revision stems and assessed whether the different fixation methods are used in similar femoral bone defects.Patients and methods - 867 patients operated on with uncemented or cemented stems in first-time hip revision surgery due to aseptic loosening performed 2006-2016 were identified in the Swedish Hip Arthroplasty Register. Preoperative femoral bone defect size was assessed on radiographs of all patients. Cox regression models were fitted to estimate the adjusted risk of re-revision during different postoperative time periods. Re-revision of any component for any reason, and stem re-revision, as well as risk of cause-specific re-revision was estimated.Results - Most patients in both fixation groups had Paprosky class IIIA femoral bone defects prior to surgery, but there were more severe bone defects in the cemented group. The adjusted risk of re-revision of any component for any reason was higher in patients with uncemented compared with those with cemented revision stems during the first 3 years after index surgery (hazard ratio [HR] 4, 95% confidence interval [CI] 2-9). From the 4th year onward, the risk of re-revision of any component for any reason was similar (HR 0.5, CI 0.2-1.4). Uncemented revision stems conferred a higher risk of dislocation compared with cemented stems (HR 5, CI 1.2-23) during the first 3 years.Interpretation - Although not predominantly used in more complex femoral defects, uncemented revision stem fixation confers a slightly higher risk of re-revision during the first years, but this risk is attenuated after longer follow-up.

Conical Primary Cementless Stem in Revision Hip Arthroplasty: 94 Consecutive Implantations at a Mean Follow-Up of 12.7 years

BACKGROUND

Revision of a failed total hip arthroplasty (THA) poses technical challenges. The use of primary stems for revision can be advantageous for maintaining bone stock and reducing complications: small case series have reported promising results in the short-term to mid-term follow-up. The aim of this study was to evaluate the long-term clinical and functional results and survivorship of a consecutive series of THA femoral component revisions using a conical primary cementless stem (PCS).

METHODS

Ninety-four stem revisions with a preoperative Paprosky I or II defect were analyzed at an average follow-up of 12.7 ± 5.4 years. Aseptic loosening was the reason for revision in 92.5% of cases. Twenty patients were lost to follow-up. Two subgroups were created: Group 1 (n = 59) underwent isolated stem revision; Group 2 (n = 15) underwent complete THA revision. All were evaluated preoperatively and postoperatively based on the Harris Hip Score (HHS), the Western Ontario and McMaster Universities Index (WOMAC) score, and the visual analog scale for pain (VAS). Residual trochanteric pain and length discrepancies were recorded. Radiographic evaluation included signs of osteolysis, subsidence, loosening, and heterotopic ossification.

RESULTS

PCS survivorship was 100% at 5 years and 95.9% at 10 years. Overall, significant postoperative improvements (P < .01) were observed on the HHS (44.3 vs 86.9), WOMAC (42.8 vs 82.8), and VAS (7.0 vs 3.0). Postoperative scores on all scales were higher for Group 1 (P < .01). Three patients (4.1%) underwent further stem revision. Demarcation lines (1 mm) were found in 12 (16.2%) patients and significant heterotopic ossifications in 22 (29.7%).

CONCLUSION

The use of PCS for stem revision in failed THA with a limited femoral bone defect is a reliable option for both isolated stem revision and concomitant cup revision in well-selected patients.

A retrospective comparison of costs for the primary and revision total knee arthroplasty in Turkey

OBJECTIVE

This study aimed to compare the cost profiles of patients who underwent a primary or revision total knee arthroplasty (TKA) and to determine the effects of the length of hospital stay, comorbidities, and septic and aseptic revision rates on the treatment costs.

METHODS

A total of 1,487 patients who underwent primary (n=1,328; 1,131 females, 197 males) or revision TKA (n=159; 137 females, 22 males) between 2010 and 2017 at our institution were retrospectively included in the current study. The patients' demographics (age and gender), the length of hospital stay, comorbidities, and septic and aseptic revision rates were collected from our hospital database. The total costs of revision and primary TKAs were calculated based on the prostheses and surgical equipment used, hospital stay, and other administrative costs in both the Turkish lira (TRY) and US dollar (USD) based on the parity of the 2 currencies from 2010 to 2017.

RESULTS

The average cost per patient for primary TKAs was 7,985±2,927 TRY (5,265 USD) in 2010 and 7,070±1,775 TRY (1,852 USD) in 2017. The average cost for revision TKAs was 13,647±4,095 TRY (8,999 USD) in 2010 and 22,806±6,155 TRY (5,973 USD) in 2017. In terms of the total costs, significant differences existed over the years, with a significantly higher difference in 2015 compared with that from 2010 to 2013 (p<0.001); however, no difference was determined among the age groups (p=0.675). The difference between the total costs of the septic (n=34; 17,964±13,028 TRY) and aseptic revisions (n=125; 23,377±12,815 TRY) was significant (p=0.001), with a higher cost for patients with septic TKAs but with no significant difference between the total costs for the patients with and without comorbidities (p=0.254). Additionally, the length of hospital stay was 2 times higher in patients with revision TKAs than in those with primary TKAs (12.3 vs 6.2 days).

CONCLUSION

Revision TKAs cause higher costs than primary TKAs, with a prolonged hospital stay. The septic background seems to be an independent predictive factor for increased costs in revision TKAs.

How is quality of life after total hip replacement related to the reconstructed anatomy? A study with low-dose stereoradiography

PURPOSE

The purpose of this study was to evaluate the relationships between the three-dimensional anatomy of operated hip in standing position using low-dose stereo-radiography imaging system and postoperative hip disability and osteoarthritis outcome score (HOOS) after total hip arthroplasty (THA).

MATERIAL AND METHODS

A total of 123 patients who underwent THA during a one-year period were included. There were 50 men and 73 women with a mean age of 67.3±13.6 (SD) years (range: 19-89 years). All patients underwent pre- and postoperative low-dose stereo-radiography examination and completed a HOOS form (score from 0 to 100, 100 for full satisfaction). We recorded 16 anatomical parameters before THA, and 15 after THA. After binary transformation of HOOS score using 70 as threshold value, outcome was assessed using logistic or generalised linear models.

RESULTS

A total of 103 patients (103/123; 83.7%) had a HOOS score≥70 and were considered as the satisfied group. A significant difference in pelvic incidence (the angle between a line perpendicular to the sacral plate at its midpoint and a line connecting the same point to the centre of the bicoxofemoral axis) was found between the satisfied 56.4±10.4 (SD)° (range: 31-85°) and the unsatisfied group 48.7±8.9 (SD)° (range: 40-65) (P=0.006). The relative variation of offset (distance from the centre of rotation of the femoral head to a line bisecting the long axis of the femur) compared to the contralateral hip was -7% in the satisfied group and 7.2% in the unsatisfied group (P=0.01).

CONCLUSION

Pelvic incidence, a parameter independent of the reconstructed anatomy, probably influences the quality of life of patients with THA, via pelvic compensatory capabilities. A loss of femoral offset negatively influences the satisfaction of patients.

Lower operating volume in shoulder arthroplasty is associated with increased revision rates in the early postoperative period: long-term analysis from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

Improved short-term outcomes have been demonstrated with higher surgical volume in shoulder arthroplasty. There is however, little data regarding long-term outcomes.

METHOD

Revision data from the Australian Orthopaedic Association National Joint Replacement Registry from 2004-2017 was analyzed according to 3 selected surgeon volume thresholds: <10, 10-20, and >20 shoulder arthroplasty cases per surgeon, per year.

RESULTS

There was a significantly higher rate of revision for stemmed total shoulder arthroplasty (TSA) for osteoarthritis (OA) for the <10/yr compared with the >20/yr group for the first 1.5 years only (hazard ratio [HR] 1.36, 95% confidence interval [CI] 1.08-1.71, P = .009). For reverse total shoulder arthroplasty (rTSA) performed for OA, there was a higher revision rate for the <10/yr compared with the >20/yr group for the first 3 months only (HR 2.58, 95% CI 1.67-3.97, P < .001). In rTSA for cuff arthropathy, there was a significantly higher rate of revision for the <10/yr compared with the >20/yr group throughout the follow-up period (HR 1.66, 95% CI 1.21-2.28, P = .001). There was no significant difference for the primary diagnosis of fracture.

CONCLUSION

Lower surgical volume was associated with higher all-cause revision rates in the early postoperative period in TSA and rTSA for OA and throughout the follow-up period in rTSA for cuff arthropathy. Despite increases in the volume of shoulder arthroplasties performed in recent years, more than 78% of surgeons undertake fewer than 10 procedures per year.

Epidemiology of Revision Total Hip Arthroplasty: An Indian Experience

BACKGROUND

With increasing numbers of primary total hip replacement (THR), there has been a substantial increase in revision total hip replacement (RTHR) surgeries. RTHR are complex joint reconstruction surgeries involving significant cost, expertise and infrastructure. With its significant socioeconomic impact, we need to keep a close watch on the epidemiological trends of these procedures.

METHODS

We prospectively studied the first-time RTHR performed at our institution for a 7-year period (2011-2017). We looked at patient demographics, the workload of RTHR and its etiology. We reviewed the microbiological profiles of septic revisions.

RESULTS

Of the 1244 THR procedures performed, 260 (21%) were first-time revisions. The predominant cause of revisions was a prosthetic infection (38%) followed by aseptic loosening (33%), instability (15%), peri-prosthetic fracture (11%) and implant breakage (3%). In the aseptic loosening group, 55% of cases had primary cemented implant, 44% had only stem loosening, 31% had cup loosening and 25% had both cup and stem loosening. In the early, midterm, and late-failure groups, prosthetic infection remained the main cause of failure. In 60% of the septic revisions, the offending organisms could not be identified and of those identified most (77%) were gram negative.

CONCLUSION

In our study, the RTHR burden was 21%, which is similar to historic revision data from the west (1998-2001) and twice as compared to recent trends from the west (9-11%). Unlike western data, which show aseptic loosening (30-60%) as the predominant cause of hip revisions, in our study infection was the number one cause (38%).

Global trends in indications for total elbow arthroplasty: a systematic review of national registries

National registries provide useful information in understanding outcomes of surgeries that have late sequelae, especially for rare operations such as total elbow arthroplasty (TEA).A systematic search was performed and data were compiled from the registries to compare total elbow arthroplasty outcomes and evaluate trends. We included six registries from Australia, the Netherlands, New Zealand, Norway, the United Kingdom and Sweden.Inflammatory arthritis was the most common indication for total elbow arthroplasty, followed by acute fracture and osteoarthritis. When comparing 2000-2009 to 2010-2017 data, total elbow arthroplasty for inflammatory arthritis decreased and total elbow arthroplasty for fracture and osteoarthritis increased. There was an increase in the number of revision TEAs over this time period.The range of indications for total elbow arthroplasty is broadening; total elbow arthroplasty for acute trauma and osteoarthritis is becoming increasingly more common. However, inflammatory arthritis remains the most common indication in recent years. This change is accompanied by an increase in the incidence of revision surgery. Cite this article: EFORT Open Rev 2020;5:215-220. DOI: 10.1302/2058-5241.5.190036.

A low-volume surgeon is an independent risk factor for leg length discrepancy after primary total hip arthroplasty: a case-control study

PURPOSE

Leg length discrepancy (LLD) is one of the bothersome complications that reduce patient satisfaction after total hip arthroplasty (THA). This study aimed to investigate the independent risk factors of LLD after primary THA.

METHODS

This is a case-control study of 163 THAs for 163 patients at our institution between April 2015 and March 2018. The relevant data about the general characteristics of the patients (age, sex, body mass index, and diagnosis), surgery (surgical approach, type of femoral stem fixation, and surgeon volume), and radiological findings (Dorr classification and pre-operative LLD) were reviewed to identify the risk factors of ≥ 5 mm post-operative LLD according to radiological measurement and to calculate odds ratios (OR) via logistic regression analysis.

RESULTS

The median (interquartile) absolute value of post-operative LLD was 3.9 (2.3-7.4) mm, and 57 (35.0%) patients had LLD of ≥ 5 mm. After controlling for possible confounders, a low-volume surgeon was considered the only independent risk factor of post-operative LLD (adjusted OR: 8.26; 95% confidence interval: 3.48, 19.60; P < 0.001). Among the 103 patients performed by high-volume surgeons, 82 (79.6%) had LLD of < 5 mm, whereas among the 60 patients performed by low-volume surgeons, only 24 (40.0%) achieved LLD of < 5 mm (P < 0.001).

CONCLUSION

A low-volume surgeon is associated with an increased risk of a post-operative LLD after primary THA, and the importance of measurements should be recognized to prevent post-operative LLD and achieve optimal outcomes. Moreover, surgeons must inform patients about the risk of developing LLD pre-operatively.

Annual case volume is a risk factor for 30-day unplanned readmission after open reduction and internal fixation of acetabular fractures

BACKGROUND

Surgical fixation of acetabular fractures is technically challenging, and quality of reduction directly correlates to patient outcomes. Considering the difficulty of open reduction and internal fixation (ORIF), increased case volumes may improve patient outcomes. No studies have investigated case volume as a risk factor for readmission after acetabular fracture ORIF. The present study sought to answer the question of whether annual case volume is a risk factor for 30-day unplanned readmission after acetabular fracture ORIF, if there is an identifiable threshold number of cases most predictive of a readmission, and if differences exist between reasons for readmission between high and low-volume centers.

HYPOTHESIS

Institutions with a lower annual case volume will have a higher incidence of 30-day unplanned readmissions.

MATERIALS AND METHODS

The national readmissions database (NRD) was queried for acetabular fractures that underwent ORIF during 2016. Comorbid conditions were summed, and annual hospital case volume was identified. A receiver operating characteristic (ROC) curve was generated and the Youden index identified threshold case volume most predictive of a 30-day readmission. A multivariable logistic regression was performed with 30-day readmission as the dependent variable and case volume below the threshold an independent variable.

RESULTS

A total of 3,407 cases were included with a median age of 43. The 30-day readmission for this cohort was 6.5% (220/3407). ROC curve analysis identified 22 annual cases as the threshold value most predictive of 30-day readmission. Multivariable logistic regression identified age (Odds Ratio (OR)=1.01, p=0.005), number of comorbidities (OR=1.35, p<0.0001), and ≤22 cases (OR=1.50, p=0.006) as statistically significant risk factors for 30-day readmission. The most common reason for readmission at both high and low-volume centers was surgical site infection.

DISCUSSION

Annual case volume is a statistically significant predictor of 30-day readmission after acetabular fracture ORIF. Performing ≤22 acetabular ORIFs places patients at greater risk for a readmission. Patients at low-volume centers may be predisposed to readmission, and it is paramount to optimize patients prior to discharge, and have appropriate surgeon and hospital resources to treat these complex injuries.

LEVEL OF EVIDENCE

III, Cross-sectional study.

Revision Joint Arthroplasty and Renal Transplant: A Matched Control Cohort Study

BACKGROUND

There is little literature concerning clinical outcomes following revision joint arthroplasty in solid organ transplant recipients. The aims of this study are to (1) analyze postoperative outcomes and mortality following revision hip and knee arthroplasty in renal transplant recipients (RTRs) compared to non-RTRs and (2) characterize common indications and types of revision procedures among RTRs.

METHODS

A retrospective Medicare database review identified 1020 RTRs who underwent revision joint arthroplasty (359 revision total knee arthroplasty [TKA] and 661 revision total hip arthroplasty [THA]) from 2005 to 2014. RTRs were compared to their respective matched control groups of nontransplant revision arthroplasty patients for hospital length of stay, readmission, major medical complications, infections, septicemia, and mortality following revision.

RESULTS

Renal transplantation was significantly associated with increased length of stay (6.12 ± 7.86 vs 4.33 ± 4.29, P < .001), septicemia (odds ratio [OR], 2.52; 95% confidence interval [CI], 1.83-3.46; P < .001), and 1-year mortality (OR, 2.71; 95% CI, 1.51-4.53; P < .001) following revision TKA. Among revision THA patients, RTR status was associated with increased hospital readmission (OR, 1.23; 95% CI, 1.03-1.47; P = .023), septicemia (OR, 1.82; 95% CI, 1.41-2.34; P < .001), and 1-year mortality (OR, 2.65; 95% CI, 1.88-3.66; P < .001). The most frequent primary diagnoses associated with revision TKA and THA among RTRs were mechanical complications of prosthetic implant.

CONCLUSION

Prior renal transplantation among revision joint arthroplasty patients is associated with increased morbidity and mortality when compared to nontransplant recipients.

Effect of hospital volume on outcomes of total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

A shift in the healthcare system towards the centralization of common yet costly surgeries, such as total hip arthroplasty (THA), to high-volume centers of excellence, is an attempt to control the economic burden while simultaneously enhancing patient outcomes. The "volume-outcome" relationship suggests that hospitals performing more treatment of a given type exhibit better outcomes than hospitals performing fewer. This theory has surfaced as an important factor in determining patient outcomes following THA. We performed a systematic review with meta-analyses to review the available evidence on the impact of hospital volume on outcomes of THA.

MATERIALS AND METHODS

We conducted a review of PubMed (MEDLINE), OVID MEDLINE, Google Scholar, and Cochrane library of studies reporting the impact of hospital volume on THA. The studies were evaluated as per the inclusion and exclusion criteria. A total of 44 studies were included in the review. We accessed pooled data using random-effect meta-analysis.

RESULTS

Results of the meta-analyses show that low-volume hospitals were associated with a higher rate of surgical site infections (1.25 [1.01, 1.55]), longer length of stay (RR, 0.83[0.48-1.18]), increased cost of surgery (3.44, [2.57, 4.30]), 90-day complications (RR, 1.80[1.50-2.17]) and 30-day (RR, 2.33[1.27-4.28]), 90-day (RR, 1.26[1.05-1.51]), and 1-year mortality rates (RR, 2.26[1.32-3.88]) when compared to high-volume hospitals following THA. Except for two prospective studies, all were retrospective observational studies.

CONCLUSIONS

These findings demonstrate superior outcomes following THA in high-volume hospitals. Together with the reduced cost of the surgical procedure, fewer complications may contribute to saving considerable opportunity costs annually. However, a need to define objective volume-thresholds with stronger evidence would be required.

TRIAL REGISTRATION

PROSPERO CRD42019123776.

The Accolade TMZF stem fulfils the demands of modern stem design: Minimum 5-year survival in a cohort of 937 patients

PURPOSE

Modern hip stem design includes a prosthesis that has a predictable outcome in all total hip arthroplasty (THA) patients, regardless of approach, surgeon or patient characteristics. Introduction without a learning curve and, in cases of problems, the possibility for a simple revision are other prerequisites. The purpose of this study is to evaluate whether the Accolade TMZF stem (Stryker Orthopedics, Mahwah, New Jersey, USA) is suitable to fulfil these demands. We report our mid-term survival of the Accolade TMZF hip stem in all patients from the first implantation at our institute.

METHODS

From the start of using the Accolade TMZF stem (March 2009) until February 2011, 937 THA were performed by 12 surgeons using a posterolateral or anterolateral approach. Survival of the stem was calculated using Kaplan-Meier analysis. Effect of approach, patient age and comorbidity were analysed with a Cox proportional hazards' model. The learning effect was determined by comparing the number of revisions in the surgeons' first 20 THAs with their next 30 THAs and the subsequent THAs.

RESULTS

At 5 years, cumulative stem survival was 97.9% based on revisions for all reasons and 98.8% with aseptic loosening as endpoint. We found no effect of surgical approach, patient age or comorbidity on stem survival. No learning effect was found.

CONCLUSION

The Accolade TMZF stem fulfilled the demands of modern stem design.

Does Hospital Volume Affect Outcomes in Spine Surgeries? A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To assess the impact of hospital volume on postoperative outcomes in spine surgery.

SUMMARY OF BACKGROUND DATA

Several strategies have recently been proposed to optimize provider outcomes, such as regionalization to higher volume centers and setting volume benchmarks.

MATERIALS AND METHODS

We performed a systematic review examining the association between hospital volume and spine surgery outcomes. To be included in the review, the study population had to include patients undergoing a primary or revision spinal procedure. These included anterior/posterior cervical fusions, anterior/posterior lumbar fusions, laminectomies, discectomies, spinal deformity surgeries, and surgery for spinal malignancies. We searched the Pubmed, OVID MEDLINE (1966-2018), Google Scholar, and Web of Science (1900-2018) databases in January 2018 using the search criteria ("Hospital volume" OR "volume" OR "volume-outcome" OR "volume outcome") AND ("spine" OR "spine surgery" OR "lumbar" OR "cervical" OR "decompression" OR "deformity" OR "fusions"). There were no restrictions placed on study design, publication date, or language. The studies were evaluated with respect to the quality of methodology as outlined by the Grading of Recommendations Assessment, Development, and Evaluation system.

RESULTS

Twelve studies were included in the review. Studies were variable in defining hospital volume thresholds. Higher hospital volume was associated with statistically significant lower risks of postoperative complications, a shorter length of stay, lower cost of hospital stay, and a lower risk of readmissions and reoperations/revisions.

CONCLUSIONS

Our findings suggest a trend toward better outcomes for higher volume hospitals; however, further study needs to be carried out to define objective volume thresholds for specific spine surgeries for hospitals to use as a marker of proficiency.

Homogeneity in prediction of survival probabilities for subcategories of hipprosthesis data: the Nordic Arthroplasty Register Association, 2000-2013

Introduction: The four countries in the Nordic Arthroplasty Register Association (NARA) share geographic proximity, culture, and ethnicity. Pooling data from different sources in order to obtain higher precision and accuracy of survival-probability estimates is appealing. Nevertheless, survival probabilities of hip replacements vary between the countries. As such, risk prediction for individual patients within countries may be problematic if data are merged. In this study, our primary question was to address when data merging for estimating prosthesis survival in subcategories of patients is advantageous for survival prediction of individual patients, and at what sample sizes this may be advised.

Methods: Patients undergoing total hip replacements for osteoarthritis between January 1, 2000 and December 31, 2013 in the four Nordic countries were studied. A total of 184,507 patients were stratified into 360 patient subcategories based on country, age-group, sex, fixation, head size, and articulation. For each patient category, we determined the sample size needed from a single country to obtain a more accurate and precise estimate of prosthesis-survival probability at 5 and 10 years compared to an estimate using data from all countries. The comparison was done using mean-square error.

Results: We found large variations in the sample size needed, ranging from 40 to 2,060 hips, before an estimate from a single Nordic country was more accurate and precise than estimates based on the NARA data.

Conclusion: Using pooled survival-probability estimates for individual risk prediction may be imprecise if there is heterogeneity in the pooled data sources. By applying mean-square error, we demonstrate that for small sample sizes, applying the larger NARA database may provide a more accurate and precise estimate; however, this effect is not consistent and varies with the characteristics of the subcategory.

The what, when and how of orthopaedic registers: an introduction into register-based research

Establishment of orthopaedic registers started in 1975 and many registers have been initiated since. The main purpose of registers is to collect information on patients, implants and procedures in order to monitor and improve the outcome of the specific procedure.

Data validity reflects the quality of the registered data and consists of four major aspects: coverage of the register, registration completeness of procedures/patients, registration completeness of variables included in the register and accuracy of registered variables.

Survival analysis is often used in register studies to estimate the incidence of an outcome. The most commonly used survival analysis is the Kaplan–Meier survival curves, which present the proportion of patients who have not experienced the defined event (e.g. death or revision of a prosthesis) in relation to the time. Depending on the research question, competing events can be taken into account by using the cumulative incidence function. Cox regression analysis is used to compare survival data for different groups taking differences between groups into account.

When interpreting the results from observational register-based studies a number of factors including selection bias, information bias, chance and confounding have to be taken into account. In observational register-based studies selection bias is related to, for example, absence of complete follow-up of the patients, whereas information bias is related to, for example, misclassification of exposure (e.g. risk factor of interest) or/and outcome.

The REporting of studies Conducted using Observational Routinely-collected Data guidelines should be used for studies based on routinely-collected health data including orthopaedic registers.

Linkage between orthopaedic registers, other clinical quality databases and administrative health registers may be of value when performing orthopaedic register-based research.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180097

The benefits of collaboration: the Nordic Arthroplasty Register Association

The Nordic Arthroplasty Register Association (NARA) was established in 2007 by arthroplasty register representatives from Sweden, Norway and Denmark with the overall aim to improve the quality of research and thereby enhance the possibility for quality improvement with arthroplasty surgery. Finland joined the NARA collaboration in 2010.

NARA minimal hip, knee and shoulder datasets were created with variables that all countries can deliver. They are dynamic datasets, currently with 25 variables for hip arthroplasty, 20 for knee arthroplasty and 20 for shoulder arthroplasty.

NARA has published statistical guidelines for the analysis of arthroplasty register data. The association is continuously working on the improvement of statistical methods and the application of new ones.

There are 31 published peer-reviewed papers based on the NARA databases and 20 ongoing projects in different phases. Several NARA publications have significantly affected clinical practice. For example, metal-on-metal total hip arthroplasty and resurfacing arthroplasty have been abandoned due to increased revision risk based on i.a. NARA reports. Further, the use of uncemented total hip arthroplasty in elderly patients has decreased significantly, especially in Finland, based on the NARA data.

The NARA collaboration has been successful because the countries were able to agree on a common dataset and variable definitions. The collaboration was also successful because the group was able to initiate a number of research projects and provide answers to clinically relevant questions. A number of specific goals, set up in 2007, have been achieved and new one has emerged in the process.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180058

Geographical variations in patient-reported outcomes after total hip arthroplasty between 2008 - 2012

BACKGROUND

Health care on equal terms is a cornerstone of the Swedish health care system. Total hip arthroplasty (THA) is considered a success story in Sweden with low frequency of reoperations and restored health-related quality of life (HRQoL). Administratively, health care in Sweden is locally self-governed by 21 counties. In this longitudinal nation-wide observational study we assessed the possible geographical variations in 1-year follow-up patient-reported outcomes (PROs): EQ-5D index, EQ VAS, Pain VAS and Satisfaction VAS.

METHODS

Study population consisted of 36,235 Swedish THA patients, operated during 2008 to 2012 due to hip osteoarthritis. Individual data came from Swedish Hip Arthroplasty Register, Statistics Sweden and National Board of Health and Welfare. We used descriptive statistics together with multivariable regression analysis to analyse the data.

RESULTS

We observed county level differences in both preoperative and postoperative PROs. The results showed that the differences observed in preoperative PROs could not fully explain the differences observed in postoperative PROs, even after adjustment for patient demographics (age, sex, BMI, Elixhauser comorbidity index, marital status, educational level and disposable income). This indicates that other factors might influence the outcome after THA.

CONCLUSION

Likely, structural and process differences such as indication for surgery have an influence on PROs after surgery. Standardization of care at hospital levels may decrease geographical variations in postoperative HRQoL. Remaining differences will then possibly be associated to patient demographics.

Influence of Hospital Volume of Procedures by Year on the Risk of Revision of Total Hip and Knee Arthroplasties: A Propensity Score-Matched Cohort Study

The volume of total hip (THA) and knee arthroplasties (TKA) performed in a hospital per year could be an influential factor on the revision of these procedures. The aims of this study were: To obtain comparable cohorts in higher- and lower-volume hospitals; and to assess the association between the hospital volume and the incidence of revision. Data from patients undergoing THA and TKA caused by osteoarthritis and recorded in the Catalan Arthroplasty Register (RACat) between January 2005 and December 2016 were used. The main explanatory variable was hospital volume by year (higher/lower). The cut-off point was fixed, based on previous research, at 50 THA and 125 TKA procedures/year. To obtain comparable populations, a propensity-score matching method (1:1) was used. Patient characteristics prior to and after matching were compared. To assess differences by volume, subhazard ratios (SHRs) from competing risks models were obtained. After matching, 13,772 THA and 36,316 TKA patients remained in the study. Prior to matching, in both joints, significant differences in all confounders were observed between volume groups. After matching, none of them remained significant. Both in THA and TKA, a higher risk of revision in higher-volume hospitals was observed (THA SHR: 1.25, 95%CI: 1.02–1.53; and TKA SHR: 1.29, 95%CI: 1.16–1.44). Unlike other contexts, currently in Catalonia, higher-volume hospitals have a greater risk of revision than lower-volume hospitals. Further research could be valuable to define context-dependent measures to reduce the incidence of revision.

What Is the Association Between Hospital Volume and Complications After Revision Total Joint Arthroplasty: A Large-database Study

BACKGROUND

Studies of primary total joint arthroplasty (TJA) show a correlation between hospital volume and outcomes; however, the relationship of volume to outcomes in revision TJA is not well studied.

QUESTIONS/PURPOSES

We therefore asked: (1) Are 90-day readmissions more likely at low-volume hospitals relative to high-volume hospitals after revision THA and TKA? (2) Are in-hospital and 90-day complications more likely at low-volume hospitals relative to high-volume hospitals after revision THA and TKA? (3) Are 30-day mortality rates higher at low-volume hospitals relative to high-volume hospitals after revision THA and TKA?

METHODS

Using 29,948 inpatient stays undergoing revision TJA from 2008 to 2014 in the Statewide Planning and Research Cooperative System (SPARCS) database for New York State, we examined the relationship of hospital revision volume by quartile and outcomes. The top 5 percentile of hospitals was included as a separate cohort. Advantages of the SPARCS database include comprehensive catchment of all cases regardless of payer, and the ability to track each patient across hospital admissions at different institutions within the state. The outcomes of interest included 90-day all-cause readmission rates and 30- and 90-day reoperation rates, postoperative complication rates, and 30-day mortality rates. The initial cohort that met the MS-DRG and ICD-9 criteria consisted of 30,354 inpatient stays for revision hip or knee replacements. Exclusions included patients with a missing patient identifier (n = 221), missing admission or discharge dates (n = 5), and stays from hospitals that were closed during the study period (n = 180). Our final analytic cohort comprised 29,948 inpatient stays for revision hip and knee replacements from 25,977 patients who had nonmissing data points for the variables of interest. Outcomes were adjusted for underlying hospital, surgeon, and patient confounding variables. The analytic cohort included observations from 25,977 patients, 138 hospitals, 929 surgeons, 14,130 revision THAs, 11,847 revision TKAs, 15,341 female patients (59% of cohort).

RESULTS

Patients had lower all-cause 90-day readmission rates in the highest 5th percentile by volume hospitals relative to all other lower hospital volume categories. Reoperation rates within the first 90 days, however, were not different among volume categories. All-cause 90-day readmissions were higher in the quartile 4 hospitals excluding the top 5th percentile (17%) versus the top 5th percentile by volume hospitals (12%) (odds ratio [OR]: 1.3; 95% confidence interval [CI], 1.0-1.5; p = 0.030). All-cause 90-day readmissions were higher in the quartile 3 hospitals (18%) relative to the top 5 percentile by volume hospitals (12%) (OR: 1.5; 95% CI, 1.2-1.9; p < 0.001). All-cause 90-day readmissions were higher in quartile 2 hospitals (18%) relative to the top 5 percentile by volume hospitals (12%) (OR: 1.4; 95% CI, 1.1-1.8; p = 0.010). All-cause 90-day readmissions were higher in quartile 1 hospitals (21%) versus the top 5 percentile by volume hospitals (12%) (OR: 1.6; 95% CI, 1.1-2.3; p = 0.010). Postoperative complication rates were higher among only the quartile 1 hospitals compared with institutions in each higher-volume category after revision TJA. The odds of 90-day complications compared with quartile 1 hospitals were 0.49 (95% CI, 0.33-0.72; p = 0.010) for quartile 2, 0.60 (95% CI, 0.40-0.88; p = 0.010) for quartile 3, 0.43 (95% CI, 0.28-0.64; p = 0.010) for quartile 4 excluding top 5 percentile, and 0.36 (95% CI, 0.22-0.59; p = 0.010) for the top 5 percentile of hospitals. There does not appear to be an association between 30-day mortality rates and hospital volume in revision TJA. The odds of 30-day mortality compared with quartile 1 hospitals were 0.54 (95% CI, 0.20-1.46; p = 0.220) for quartile 2, 0.75 (95% CI, 0.30-1.91; p = 0.550) for quartile 3, 0.57 (95% CI, 0.22-1.49; p = 0.250) for quartile 4 excluding top 5 percentile, and 0.61 (95% CI, 0.20-1.81; p = 0.370) for the top 5 percentile of hospitals.

CONCLUSIONS

These findings suggest that regionalizing revision TJA services, or concentrating surgical procedures in higher-volume hospitals, may reduce early complications rates and 90-day readmission rates. Disadvantages of regionalization include reduced access to care, increased patient travel distances, and possible capacity issues at receiving centers. Further studies are needed to evaluate the benefits and negative consequences of regionalizing revision TJA services to higher-volume revision TJA institutions.

LEVEL OF EVIDENCE

Level III, therapeutic study.

High annual surgeon volume reduces the risk of adverse events following primary total hip arthroplasty: a registry-based study of 12,100 cases in Western Sweden

Background and purpose - Most earlier publications investigating whether annual surgeon volume is associated with lower levels of adverse events (AE), reoperations, and mortality are based on patient cohorts from North America. There is also a lack of adjustment for important confounders in these studies. Therefore, we investigated whether higher annual surgeon volume is associated with a lower risk of adverse events and mortality within 90 days following primary total hip arthroplasty (THA). Patients and methods - We collected information on primary total hip arthroplasties (THA) performed between 2007 and 2016 from 10 hospitals in Western Sweden. These data were linked with the Swedish Hip Arthroplasty Register and a regional patient register. We used logistic regression (simple and multiple) adjusted for age, sex, comorbidities, BMI, fiation technique, diagnosis, surgical approach, time in practice as orthopedic specialist and annual volume. Annual surgeon volume was calculated as the number of primary THAs the operating surgeon had performed 365 days prior to the index THA. Results - 12,100 primary THAs, performed due to both primary and secondary osteoarthritis by 268 different surgeons, were identified. The median annual surgeon volume was 23 primary THAs (range 0-82) 365 days prior to the THA of interest and the mean risk of AE within 90 days was 7%. If the annual volume increased by 10 primary THAs in the simple logistic regression the risk of AE decreased by 10% and in the adjusted multiple regression the corresponding number was 8%. The mortality rate in the study was low (0.2%) and we could not find any association between 90-day mortality and annual surgeon volume. Interpretation - High annual surgical activity is associated with a reduced risk of adverse events within 90 days. Based on these findings healthcare providers should consider planning for increased surgeon volume.

Evidence-Based Thresholds for the Volume and Cost Relationship in Total Hip Arthroplasty: Outcomes and Economies of Scale

BACKGROUND

High-volume surgeons and hospital systems have been shown to deliver higher-value care in several studies. However, no evidence-based volume thresholds for cost currently exist in total hip arthroplasty (THA). The objective of this study was to establish meaningful thresholds in cost for surgeons and hospitals performing THA. A secondary objective was to analyze the market share of THAs for each surgeon and hospital stratifications.

METHODS

Using a database of 136,501 patients undergoing THA, we used stratum-specific likelihood ratio analysis of a receiver operating characteristic curve to generate volume thresholds based on costs for surgeons and hospitals. In addition, we examined the relative proportion of annual THA cases performed by each surgeon and hospital stratifications.

RESULTS

Stratum-specific likelihood ratio analysis of cost by annual surgeon THA volume produced stratifications at: 0-73 (low), 74-123 (medium), and 124 or more (high). Analysis by annual hospital THA volume produced stratifications at: 0-121 (low), 122-309 (medium), and 310 or more (high). Hospital costs decreased significantly (P < .05) in progressively higher volume stratifications. High-volume centers perform the largest proportion of THA cases (48.6%); however, low volume surgeons perform the greatest share of these cases (44.6%).

CONCLUSION

Our study establishes economies of scale in THA by demonstrating a direct relationship between volume and cost reduction. High-volume hospitals are performing the greatest proportion of THAs; however, low-volume surgeons perform the largest share of these cases, which highlights a potential area for enhanced value in the care of patients undergoing THA.

Risk-Based Hospital and Surgeon-Volume Categories for Total Hip Arthroplasty

BACKGROUND

Studies of volume-outcome relationships typically subdivide volume via non-evidence-based methods, producing categories that vary widely among studies, preclude the comparison of results, and possibly obscure the true volume-outcome relationships. The goal of the current study was to use quantitative methods to derive meaningful, risk-based categories for hospital and surgeon total hip arthroplasty (THA) volume based on relationships with mortality, complications, and revision.

METHODS

Using New York statewide patient data (1997 to 2014; n = 187,557), we derived risk-based hospital and surgeon-volume categories for primary THA based on relationships with 90-day complications and mortality and 2-year revision.

RESULTS

The following categories, based on relationships with complications, mortality, and revision, were derived for surgeon volume: 0 to 12, 13 to 25, 26 to 72, 73 to 165, 166 to 279, and ≥280 THA/year. For hospital volume, the categories derived were 0 to 11, 12 to 54, 55 to 157, 158 to 526, and ≥527 THA/year. More than 35% of THA cases in New York State were conducted by surgeons performing ≤1 THA/month (0 to 12 THA/year), and these were associated with a 2 to 2.5-fold increase in the risk for complications, mortality, and revision relative to higher-volume surgeons. Similarly, 15% of THA cases in New York State were conducted in hospitals performing ≤1 THA/week (0 to 11 or 12 to 54 THA/year), and these were associated with a nearly 1.5-fold increase in complications and between a 4 and 6-fold increase in mortality. Traditional non-evidence-based quartile categories were concentrated at lower volumes, did not capture the full magnitude of the volume-related differences, and were a poorer representation of the outcome data, as assessed by several model metrics. Thus, quartiles showed only a <2-fold increase in complications, mortality, and revision for the lowest versus the highest surgeon-volume quartile and failed to show the increased risk for lower versus higher hospital volumes.

CONCLUSIONS

The volume-outcome relationships in THA are more pronounced than previously apparent through standard statistical techniques. Volume-based strategies for improving outcomes in THA should use benchmarks that are evidence-based to achieve optimal results.

LEVEL OF EVIDENCE

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

Evidence-Based Thresholds for the Volume and Length of Stay Relationship in Total Hip Arthroplasty: Outcomes and Economies of Scale

BACKGROUND

Several studies have indicated that high-volume surgeons and hospitals deliver higher value care. However, no evidence-based volume thresholds currently exist in total hip arthroplasty (THA). The primary objective of this study was to establish meaningful thresholds taking patient outcomes into consideration for surgeons and hospitals performing THA. A secondary objective was to examine the market share of THAs for each surgeon and hospital strata.

METHODS

Using 136,501 patients undergoing hip arthroplasty, we used stratum-specific likelihood ratio (SSLR) analysis of a receiver-operating characteristic curve to generate volume thresholds predictive of increased length of stay (LOS) for surgeons and hospitals. Additionally, we examined the relative proportion of annual THA cases performed by each surgeon and hospital strata established.

RESULTS

SSLR analysis of LOS by annual surgeon THA volume produced 3 strata: 0-69 (low), 70-121 (medium), and 121 or more (high). Analysis by annual hospital THA volume produced strata at: 0-120 (low), 121-357 (medium), and 358 or more (high). LOS decreased significantly (P < .05) in progressively higher volume categories. High-volume hospitals performed the majority of cases, whereas low-volume surgeons performed the majority of THAs.

CONCLUSION

Our study validates economies of scale in THA by demonstrating a direct relationship between volume and value for THA through risk-based volume stratification of surgeons and hospitals using SSLR analysis of receiver-operating characteristic curves to identify low-, medium-, and high-volume surgeons and hospitals. While the majority of primary THAs are performed at high-volume centers, low-volume surgeons are performing the majority of these cases, which may offer room for improvement in delivering value-based care.

Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases

Background

High procedure volume and dedication to unicompartmental knee arthroplasty (UKA) has been suggested to improve revision rates. This study aimed to quantify the annual hospital volume effect on revision risk in Oxfordu nicompartmental knee arthroplasty in the Nordic countries.

Methods

14,496 cases of cemented medial Oxford III UKA were identified in 126 hospitals in the four countries included in the Nordic Arthroplasty Register Association (NARA) database from 2000 to 2012. Hospitals were divided by quartiles into 4 annual procedure volume groups (≤11, 12-23, 24-43 and ≥44). The outcome was revision risk after 2 and 10 years calculated using Kaplan Meier method. Multivariate Cox regression analysis was used to assess the Hazard Ratio (HR) of any revision due to specific reasons with 95% confidence intervals (CI).

Results

The implant survival was 80% at 10 years in the volume group ≤11 procedures per year compared to 83% in other volume groups. The HR adjusted for age category, sex, year of surgery and nation was 0.87 (95% CI: 0.76-0.99, p = 0.036) for the group 12-23 procedures per year, 0.78 (95% CI: 0.68-0.91, p = 0.002) for the group 24-43 procedures per year and 0.82 (95% CI: 0.70-0.94, p = 0.006) for the group ≥44 procedures per year compared to the low volume group. Log-rank test was p = 0.003. The risk of revision for unexplained pain was 40-50% higher in the low compared with other volume groups.

Conclusion

Low volume hospitals performing ≤11 Oxford III UKAs per year were associated with an increased risk of revision compared to higher volume hospitals, and unexplained pain as revision cause was more common in low volume hospitals.

Monitoring Outcome of Joint Arthroplasty in Italy: Implementation of the National Registry

Purpose  Arthroplasty registries have an important role in improving outcomes in joint surgery. As the demand for joint arthroplasty continues to increase, growing attention is being paid to the establishment of national registries, which contribute to the enhancement of the quality of patients' care. Indeed, providing postmarketing surveillance data in terms of safety and effectiveness of medical devices, registries contribute to the best orthopaedic practice and support public health decision making. In this context, a project aimed at implementing a national arthroplasty registry in Italy has appeared to be essential, and the activities performed in the last years have consolidated data collection of hip and knee replacements.

Methods  Based on a close cooperation among public health institutions, clinicians, and involved stakeholders, the architecture of the registry is built on three pillars: (1) data collected using Hospital Discharge Records (HDRs) integrated by an additional dataset, (2) implants identified and characterized in a dedicated medical devices library, and (3) a federation of regional registries coordinated by a public health institution, the Italian National Institute of Health.

Results  Besides the organizational structure, statistical analyses on joint arthroplasty from national HDR database (2001–2014) and Italian registry data (2014) are presented. Currently, the institutions participating in the registry on a voluntary basis show 80% of completeness for hip and 58% for knee, and represent approximately 18% of the national volume.

Conclusion  To make data collection effective, participation should be mandatory and ruled by a national law.

Level of Study  Level III, observational analytic study.

All-Cause Versus Complication-Specific Readmission Following Total Knee Arthroplasty

BACKGROUND

Unplanned readmissions have become an important quality indicator, particularly for reimbursement; thus, accurate assessment of readmission frequency and risk factors for readmission is critical. The purpose of this study was to determine (1) the frequency of and (2) risk factors for readmissions for all causes or procedure-specific complications within 30 days after total knee arthroplasty (TKA) as well as (3) the association between hospital volume and readmission rate.

METHODS

The Statewide Planning and Research Cooperative System (SPARCS) database from the New York State Department of Health was used to identify 377,705 patients who had undergone primary TKA in the period from 1997 to 2014. Preoperative diagnoses, comorbidities, and postoperative complications were determined using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Readmission was defined as all-cause, due to complications considered by the Centers for Medicare & Medicaid Services (CMS) to be TKA-specific, or due to an expanded list of TKA-specific complications based on expert opinion. Multivariable logistic regression analysis was utilized to determine the independent predictors of readmission within 30 days after surgery.

RESULTS

There were 22,076 all-cause readmissions-a rate of 5.8%, with a median rate of 3.9% (interquartile range [Q1, Q3] = 1.1%, 7.2%]) among the hospitals-within 30 days after discharge. Of these, only 11% (0.7% of all TKAs) were due to complications considered to be TKA-related by the CMS whereas 31% (1.8% of all TKAs) were due to TKA-specific complications on the expanded list based on expert opinion. Risk factors for TKA-specific readmissions based on the expanded list of criteria included an age of >85 years (odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.15 to 1.52), male sex (OR = 1.41, 95% CI = 1.34 to 1.49), black race (OR = 1.24, 95% CI = 1.14 to 1.34), Medicaid coverage (OR = 1.40, 95% CI = 1.26 to 1.57), and comorbidities. Several comorbid conditions contributed to the all-cause but not the TKA-specific readmission risk. Very low hospital volume (<90 cases per year) was associated with a higher readmission risk.

CONCLUSIONS

The frequency of readmissions for TKA-specific complications was low relative to the frequency of all-cause readmissions. Reasons for hospital readmission are multifactorial and may not be amenable to simple interventions. Health-care-quality measurement of readmission rates should be calculated and risk-adjusted on the basis of procedure-specific criteria.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Current Epidemiology of Revision Total Hip Arthroplasty in the United States: National Inpatient Sample 2009 to 2013

BACKGROUND

Despite the excellent outcomes associated with primary total hip arthroplasty (THA), implant failure and revision continues to burden the healthcare system. THA failure has evolved and displays variability throughout the literature. In order to understand how THAs are failing and how to reduce this burden, it is essential to assess modes of implant failure on a large scale. Thus, we report: (1) etiologies for revision THA; (2) frequencies of revision THA procedures; (3) patient demographics, payor type, and US Census region of revision THA patients; and (4) the length of stay and total costs based on the type of revision THA procedure.

METHODS

We queried the National Inpatient Sample database for all revision THA procedures performed between January 1, 2009 and December 31, 2013. This yielded 258,461 revision THAs. Patients specific demographics were identified in order to determine the prevalence of revision procedure performed.

RESULTS

Dislocation was the main indication for revision THA (17.3%), followed by mechanical loosening (16.8%). All-component revision was the most common procedure performed (41.8%). Patients were most commonly white (77.4%), aged 75 years and older (31.6%), and resided in the South US Census region (37.0%). The average length of stay for all procedures was 5.29 days. The mean total charge for revision THA procedures was $77,851.24.

CONCLUSION

Dislocation and mechanical loosening is the predominant indication for revision THA in the United States. With the frequency of revision THAs projected to double in the next decade, orthopedists must take steps to mitigate this potentially devastating complication.

Relative impact of hospital and surgeon procedure volumes on primary total hip arthroplasty revision: a nationwide cohort study in France

BACKGROUND

Both surgeon and hospital procedure volumes have been found to be associated with total hip arthroplasty (THA) outcomes. However, little research has been conducted on the relative influence. We studied the association between THA survivorship and both hospital and surgeon procedure volumes, considering their relative impact.

METHODS

A population-based cohort included all patients aged ≥40 years having received a unilateral primary THA from 2010 to 2011, from the French National Health Insurance Database. Patients were followed up until the end of 2014. The outcome was THA revision. Exposures of interest were procedure volumes, divided into tertiles: <1.5, 1.5-4, >4 and <7, 7-15, >15 procedures per month defined as low, medium, and high volumes for surgeon and hospital, respectively.

RESULTS

The cohort had 62,906 patients, with mean age 69 years and women 57%. Mean surgeon and hospital volumes were 8 and 23 procedures per month, respectively, and 5%, 72%, 22% and 7%, 28%, 65% of THAs were implanted by a low-, medium-, and high-volume surgeon or in a low-, medium-, and high-volume hospital, respectively. Median follow-up was 45 months (range, 0-57 months). In multivariate analysis, adjusted for both surgeon and hospital volumes, for patient and THA characteristics, a lower surgeon volume was associated with poorer THA survivorship (adjusted hazard ratio [aHR] = 1.19; 95% confidence interval [CI], 1.07-1.34 and aHR = 1.70; 95% CI, 1.40-2.05, for medium- and low-volume surgeon, respectively, compared with that of high volume), whereas hospital volume was not.

CONCLUSIONS

This study brings evidence to support the notion that THAs performed by high-volume surgeons in French private hospitals have higher survivorship in the first 4 years.