Clinical benefit and cost effectiveness of total knee arthroplasty in the older patient

Orthopaedic surgeons' attitude toward physical activity for people after total hip or knee replacement: Northern vs Southern European country

BACKGROUND

Regular physical activity (PA) is a key factor of lifestyle behavior enhancing general health and fitness, especially in people after total hip or knee replacement (THR and TKR). Orthopaedic surgeons can play a primary role in advocating the benefits of an active lifestyle. Aim of the study was 1) to assess the attitude of orthopaedic surgeons towards PA for people after THR/TKR and 2) to compare the attitude between a Northern European (the Netherlands) and a Southern European (Italy) country and analyze which factors influence the attitude towards PA.

METHODS

A cross-cultural study. An (online) survey was distributed among orthopaedic surgeons in Italy and the Netherlands. Chi-square and Mann-Whitney tests were used to compare surgeons' and clinics' characteristics, and questionnaires' scores, respectively. A linear regression analysis was conducted to assess which surgeon characteristics influence attitude towards PA.

RESULTS

A cohort of 159 surgeons (103 Italians and 56 Dutch) was analyzed. The median score of overall orthopaedic surgeons' attitude towards PA was positive (57 out of 72). Dutch surgeons showed a more positive attitude compared to Italian surgeons (p < 0.01). Main difference was found in the "Physical activity concern" factor, where Italian surgeons showed more concern about the negative effects of PA on the survival of the prosthesis. The regression analyses showed that "Country" and "Type of clinic" were associated with the surgeons' attitude.

CONCLUSIONS

Overall, the orthopaedic surgeons' attitude towards PA for people with THR and TKR was positive. However, Dutch surgeons seem to be more positive compared to the Italian. The country of residence was the item that most influenced attitude. Further investigations are needed to untangle specific factors, such as cultural, socioeconomic, or contextual differences within the variable "country" that may influence orthopaedic surgeons' attitudes towards PA.

An Image-Based Augmented Reality System for Achieving Accurate Bone Resection in Total Knee Arthroplasty

Background and objective With the steady advancement of computer-assisted surgical techniques, the importance of assessing and researching technology related to total knee arthroplasty (TKA) procedures has increased. Augmented reality (AR), a recently proposed next-generation technology, is expected to enhance the precision of orthopedic surgery by providing a more efficient and cost-effective approach. However, the accuracy of image-based AR in TKA surgery has not been established. Therefore, this study aimed to determine whether accurate bone resection can be achieved in TKA surgery using image-based AR. Methods In this study, we replaced traditional CT imaging and reconstructions for creating a bone 3D model by direct 3D scanning of the femur and tibia. The preoperative planning involved identifying anatomical landmarks and determining the surgical details. During surgery, markers were employed to create a local coordinate system for an AR-assisted surgical system using a Polaris camera. This approach helped minimize discrepancies between the 3D model and actual positioning, ensuring accurate alignment. Results The AR-assisted surgery using the image method resulted in fewer errors [average error: 0.32 mm; standard deviation (SD): 0.143] between the bone resection depth of the preoperative surgical plan and the bone model test results. Conclusions Our findings demonstrated the accuracy of bone resectioning by using image-based AR-assisted navigation for TKA surgery. Image-based AR-assisted navigation in TKA surgery is a valuable tool not only for enhancing accuracy by using smart glasses and sensors but also for improving the efficiency of the procedure. Therefore, we anticipate that image-based AR-assisted navigation in TKA surgery will gain wide acceptance in practice.

Indication for total knee arthroplasty based on preoperative functional score: Are we operating earlier?

BACKGROUND

The number of total knee arthroplasty (TKA) procedures performed annually is increasing for reasons not fully explained by population growth and increasing rates of obesity. The purpose of this study was to determine the role of patient functional status as an indication for surgery and to determine if patients are undergoing surgery with a higher level of preoperative function than in the past.

METHODS

A systematic review and meta-analysis of the MEDLINE, Embase and Cochrane databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Functional status was assessed using the 36-Item Short Form Health Survey's physical component summary (PCS) score. Only primary procedures were included. Articles were screened by 2 independent reviewers, with conflicts resolved with a third reviewer. Meta-regression analysis was performed to determine the effect of time, age and sex on preoperative PCS score. Subgroup analysis was performed to compare results for the United States with those for the rest of the world.

RESULTS

A total of 1502 articles were identified, of which 149 were included in the study. Data from 257 independent groups including 57 844 patients recruited from 1991 to 2015 were analyzed. The mean preoperative PCS score was 31.1 (95% confidence interval 30.6-31.7) with a 95% prediction interval of 22.8-39.5. The variance across studies was found to be significant (p < 0.001) with 99.01% true variance. Year of enrolment, age, the percentage of female patients and geographic region did not have any significant effect on preoperative PCS score.

CONCLUSION

Patients are undergoing TKA with a level of preoperative function similar to their level of function in the past. Patient age, sex and location did not influence the functional status at which patients were considered to be candidates for surgery.

Costs and models used in the economic analysis of Total Knee Replacement (TKR): A systematic review

OBJECTIVES

The main objective of this review is to summarize the evidence on the core modelling specifications and methodology on the cost-effectiveness of TKR compared to non-surgical management. Another objective of this study is to synthesize evidence of TKR cost and compare it across countries using purchasing power parity (PPP).

METHODOLOGY

The electronic databases used for this review were MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), HTAIn repository, Cost effectiveness Analysis (CEA) registry, and Google Scholar. Consolidated Health Economic Evaluation Reporting Standards (CHEERS) was used to assess the validity of the methods and transparency in reporting the results. The Quality of Health Economic Studies (QHES) was used to check the quality of economic evaluation models of the studies included. The cost of TKR surgery from high income and low- or middle-income countries were extracted and converted to single USD ($) using purchasing power parities (PPP) method.

RESULT

Thirty-two studies were included in this review, out of which eight studies used Markov model, five used regression model, one each reported Marginal structure model, discrete simulation model, decision tree and Osteoarthritis Policy Model (OAPol) respectively to assess the cost-effectiveness of TKR. For PPP, twenty-six studies were included in the analysis of TKR cost. The average cost of TKR surgery was the lowest in developing country-India ($3457) and highest in USA ($19568).

CONCLUSION

The findings of this review showed that the Markov model was most widely used in the analysis of the cost effectiveness of TKR. Our review also concluded that the cost of TKR was higher in the developed countries as compared to the developing countries.

The Current Relationship Between Surgeon Reimbursement and Patient Complexity in Arthroplasty-A Risk-Payment Analysis of All Primary Joint Replacements Billed to Medicare in 2019

BACKGROUND

The purpose of this study was to assess surgeon reimbursement among total joint arthroplasty (TJA) patients who had differing risk profiles within the Medicare population.

METHODS

The "2019 Medicare Physician and Other Provider" file was utilized. In 2019, 441,584 primary total hip and knee arthroplasty procedures were billed to Medicare Part B. All episodes were included. Patient demographics and comorbidity profiles were collected for all patients. Additionally, mean patient hierarchal condition category (HCC) risk scores and physician reimbursements were collected. All procedure episodes were split into 2 cohorts; those with an HCC risk score of 1.5 or greater, and those with patient HCC risk scores less than 1.5. Variables were averaged for each cohort and compared.

RESULTS

The mean reimbursement across all procedures was $1,068.03. For the sicker patient cohort with a mean HCC risk score of 1.5 or greater, there was a significantly higher rate of all comorbidities compared to the cohort with HCC risk score under 1.5. The mean payment across the sicker cohort was $1,059.21, while the mean payment among the cohort with HCC risk score under 1.5 was 1,073.32 (P = .032).

CONCLUSION

This study demonstrates that for Medicare patients undergoing primary TJA in 2019, the mean surgeon reimbursement was lower for primary TJA among sick patients in comparison to their healthier counterparts, although it is difficult to ascertain the impact of this discrepancy. As alternative payment models continue to undergo evaluation and development, these data will be important for the potential advancement of more equitable reimbursement models in arthroplasty care, specifically regarding surgeon reimbursement and possible risk adjustment within such models.

Cost-effectiveness of patient specific vs conventional instrumentation for total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Over the past years, patient specific instrumentation (PSI) for total knee arthroplasty (TKA) has been implemented and routinely used. No clear answer has been given on its associated cost and cost-effectiveness when compared to conventional instrumentation (CI) for TKA.

AIM

To compare the cost and cost-effectiveness of PSI TKA compared to CI TKA.

METHODS

A literature search was performed in healthcare, economical healthcare, and medical databases (MEDLINE, EMBASE, CINAHL, Web of Science, Cochrane Library, EconLit). It was conducted in April 2021 and again in January 2022. Relevant literature included randomised controlled trials, retrospective studies, prospective studies, observational studies, and case control studies. All studies were assessed on methodological quality. Relevant outcomes included incremental cost-effectiveness ratio, quality-adjusted life years, total costs, imaging costs, production costs, sterilization associated costs, surgery duration costs and readmission rate costs. All eligible studies were assessed for risk of bias. Meta-analysis was performed for outcomes with sufficient data.

RESULTS

Thirty-two studies were included into the systematic review. Two were included in the meta-analysis. 3994 PSI TKAs and 13267 CI TKAs were included in the sample size. The methodological quality of the included studies, based on Consensus on Health Economic Criteria-scores and risk of bias, ranged from average to good. PSI TKA costs less than CI TKA when considering mean operating room time and its associated costs and tray sterilization per patient case. PSI TKA costs more compared to CI TKA when considering imaging and production costs. Considering total costs per patient case, PSI TKA is more expensive in comparison to CI TKA. Meta-analysis comparing total costs for PSI TKA, and CI TKA showed a significant higher cost for PSI TKA.

CONCLUSION

Cost for PSI and CI TKA can differ when considering distinct aspects of their implementation. Total costs per patient case are increased for PSI TKA when compared to CI TKA.

Quality of Life and Satisfaction in Patients Above and Under 65 Years Old Submitted to Total Knee Arthroplasty

Objective  To compare the level of quality of life and satisfaction after two years of total knee arthroplasties between individuals above and below 65 years of age and to identify predictor factors of poor clinical outcome and low level of satisfaction in patients undergoing arthroplasty.

Methods  This is a retrospective cohort with data from patients diagnosed with knee osteoarthritis submitted to primary total knee arthroplasty from 2014 to 2018 ( n  = 190). Clinical outcomes were assessed using the following scores: visual analog scale (VAS) of pain, EQ-5D-3L and EUROQOL-VAS (quality of life scales), patient satisfaction level, and functional scale of the Knee Injury and Osteoarthritis Outcome Score (KOOS), collected through a questionnaire applied preoperatively, as well as 1, 3, 12 and 24 months after surgery.

Results  Patients < 65 years old presented significantly lower values (clinical worsening) in KOOS-pain and KOOS-symptoms. There are no differences in the principal clinical scores that assess pain, function, and quality of life after the procedure, as well as in the rate of satisfaction with the procedure, among patients < 65 years old when compared with patients ≥ 65 years old. It was also observed that patients who were not satisfied with the procedure in the 24-month evaluation presented clinical results in some analyzed scores (KOOS-pain and EQ-VAS) similar to patients who declared themselves satisfied.

Conclusion  Scores that assess pain, function, quality of life, as well as satisfaction rate are similar between patients < 65 years old and those ≥ 65 years old.

Open Reduction Internal Fixation Versus Distal Femoral Replacement (DFR) for Treatment of OTA/AO 33C Fractures in the Elderly: A Review of Functional Outcomes and Cost Analysis

OBJECTIVES

To determine the economic cost associated with the treatment of OTA/AO 33C fractures in patients older than 65 years of age using open reduction internal fixation (ORIF) or DFR and to assess the perioperative outcomes of elderly patients treated surgically following OTA/AO 33C fractures.

DESIGN

Retrospective cohort over a 10-year period.

SETTING

A single level-1 trauma center.

PARTICIPANTS AND INTERVENTION

Thirty-nine patients 65 or older with OTA/AO 33C fractures who underwent treatment with ORIF (n = 27) or DFR (n = 12) were included.

MAIN OUTCOME MEASUREMENTS

Direct cost associated with surgical treatment along with LOS, functional outcomes, patient-reported outcomes, and all-cause reoperation.

RESULTS

Index procedure costs were as follows: DFR: $ 61,259 vs. ORIF: $44,490 (P = 0.056). Five (20%) ORIF patients required revision versus one (8%) in the DFR group. Total cost when including reoperation resulted in DFR being $14,805 more costly, which was not significant. Hospital LOS was similar between groups; however, convalescent LOS was longer in ORIF patients (43.2 vs. 23.1 days, P = 0.02).

CONCLUSION

This study demonstrates that there is no significant difference in overall cost between ORIF and DFR when all costs are considered. A larger portion of DFR patients were able to mobilize postoperatively, with subacute length of stay being longer in ORIF patients. A multicenter trial is warranted to determine optimal treatment for this complex problem.

LEVEL OF EVIDENCE

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

Equal bony resection of distal and posterior femur will lead to flexion/extension gap inequality in robot-assisted cruciate-retaining TKA

PURPOSE

Joint imbalance has become one of the main reasons for early revision after total knee arthroplasty (TKA) and it is directly related to the surgical technique. Therefore, a better understanding of how much bone has to be removed to obtain a balanced flexion/extension gap could improve current practice. The primary objective of this study was to analyse the amount of bone that needed to be removed from the distal and posterior femoral joint surfaces to obtain an equal flexion/extension gap in robot-assisted TKA. The second objective of this study was to evaluate whether the size of the knee joint influenced the amount of bony resection needed to achieve an equal flexion/extension gap in robot-assisted TKA.

METHODS

A retrospective analysis was performed on all patients receiving a robot-assisted TKA (Cruciate Retaining (n = 268)) by six surgeons from April 2018 to September 2019. The robot was used consecutively when available in all patients receiving Cruciate Retaining TKA. Gap assessment, bony resections, femoral implant size and hip-knee-ankle angle were evaluated with the robot. Femoral implant size was categorized into small (size 1-2), medium (size 3-5) and large (size 6-8).

RESULTS

The difference between the posterior and distal resection needed to obtain equal flexion and extension gap was on average 2.0 mm (SD 1.6) and 1.5 mm (SD 2.2) for the medial and lateral compartment, respectively. The discrepancy was smaller in the large implant group compared to the small implant group (p < .05 medial and lateral) and medium implant group (p < .05 medial). Varus knees required a larger differential resection compared to neutral and valgus knees (only laterally) (medial compartment: p < .05 (varus-neutral), p = .051 (varus-valgus); lateral compartment: p < .05 (varus-neutral and varus-valgus).

CONCLUSION

Removing an equal amount of bone from the distal and posterior femur will lead to flexion/extension gap imbalance in TKA. It was required to remove 1.5-2 mm more bone from the posterior femur compared to the distal femur to equalize flexion and extension gap. This effect was size dependent: in larger knees, the discrepancy between the distal and posterior resections was smaller.

LEVEL OF EVIDENCE

IV.

Surface Roughness of Titanium Orthopedic Implants Alters the Biological Phenotype of Human Mesenchymal Stromal Cells

Metal orthopedic implants are largely biocompatible and generally achieve long-term structural fixation. However, some orthopedic implants may loosen over time even in the absence of infection. In vivo fixation failure is multifactorial, but the fundamental biological defect is cellular dysfunction at the host-implant interface. Strategies to reduce the risk of short- and long-term loosening include surface modifications, implant metal alloy type, and adjuvant substances such as polymethylmethacrylate cement. Surface modifications (e.g., increased surface rugosity) can increase osseointegration and biological ingrowth of orthopedic implants. However, the localized responses of cells to implant surface modifications need to be better characterized. As an in vitro model for investigating cellular responses to metallic orthopedic implants, we cultured mesenchymal stromal/stem cells on clinical-grade titanium disks (Ti6Al4V) that differed in surface roughness as high (porous structured), medium (grit blasted), and low (bead blasted). Topological characterization of clinically relevant titanium (Ti) materials combined with differential mRNA expression analyses (RNA-seq and real-time quantitative polymerase chain reaction) revealed alterations to the biological phenotype of cells cultured on titanium structures that favor early extracellular matrix production and observable responses to oxidative stress and heavy metal stress. These results provide a descriptive model for the interpretation of cellular responses at the interface between native host tissues and three-dimensionally printed modular orthopedic implants, and will guide future studies aimed at increasing the long-term retention of such materials after total joint arthroplasty. Impact statement Using an in vitro model of implant-to-cell interactions by culturing mesenchymal stromal cells (MSCs) on clinically relevant titanium materials of varying topological roughness, we identified mRNA expression patterns consistent with early extracellular matrix (ECM) production and responses to oxidative/heavy metal stress. Implants with high surface roughness may delay the differentiation and ECM formation of MSCs and alter the expression of genes sensitive to reactive oxygen species and protein kinases. In combination with ongoing animal studies, these results will guide future studies aimed at increasing the long-term retention of widely used titanium materials after total joint arthroplasty.

A Comprehensive Monetary Analysis of Inpatient Total Hip and Knee Arthroplasties Billed to Medicare by Hospitals: 2011-2017

BACKGROUND

Total joint arthroplasty (TJA) has been a recent target of reimbursement reform. As such, the purpose of this study was to evaluate trends in Medicare reimbursement to hospitals for TJA patients from 2011 to 2017.

METHODS

The Inpatient Utilization and Payment Public Use File was queried for all primary total hip and knee arthroplasty episodes. This file includes all services billed to Medicare via the Inpatient Prospective Payment System. Extracted data included hospital charges and amount paid by Medicare. All data were adjusted for inflation to 2017 US dollars. Multiple linear mixed-model regression analyses were conducted to assess change over time, and geo-modelling was used to represent reimbursement by location.

RESULTS

A total of 3,368,924 primary TJA procedures were billed to Medicare by hospitals from 2011 to 2017 and included in the study. The mean inflation-adjusted Medicare payment to hospitals for DRG 469 decreased from $22,783.66 to $19,604.62 per procedure (-$3179.04; -14.0%; P < .001) and decreased from $13,290.79 to $11,771.54 for DRG 470 (-$1519.25; -11.4%, P = .011) from 2011 to 2017. Meanwhile, the mean charge submitted by hospitals increased by $6483.39 and $5115.60 for DRGs 469 and 470, respectively (+7.4% for 469, +9.3% for 470; P < .001). Medicare reimbursement to hospitals varied by state.

CONCLUSION

During the study period, the mean Medicare reimbursement to hospitals decreased for TJA from 2011 to 2017. Meanwhile, the average charge submitted by hospitals increased. As alternative payment models continue to undergo evaluation and development, these data are important for the advancement of more agreeable reimbursement models in arthroplasty care.

Temporal Analysis of Medicare Physician Reimbursement and Procedural Volume for all Hip and Knee Arthroplasty Procedures Billed to Medicare Part B From 2000 to 2019

BACKGROUND

The purpose of this study was to evaluate trends in annual arthroplasty volume among the Medicare population, as well as assess true Medicare reimbursement to physicians for all hip and knee arthroplasty procedures billed to Medicare since year 2000.

METHODS

The publicly available Medicare Part B National Summary Data File from years 2000 to 2019 was utilized. Collected data included true physician reimbursements for all primary total hip and knee, unicompartmental knee, and revision hip/knee arthroplasty procedures from 2000 to 2019. Monetary data was adjusted for inflation to year 2019 dollars. Change was assessed and compared by procedure type.

RESULTS

From 2000 to 2019, physicians billed Medicare Fee-for-service for 8,363,821 hip and knee arthroplasty procedures. During this time, the annual number of included arthroplasty procedures billed to Medicare increased by 100%. From 2000 to 2019 across all included procedures, the mean physician reimbursement after adjusting for inflation decreased by -$729.82 (-38.9%) per procedure. This varied by procedure type. Unicompartmental knee arthroplasty was the only procedure to experience an increased mean reimbursement when adjusting for inflation, increasing by $241.40 (+16.6%) per procedure from 2000 to 2019.

CONCLUSION

This study demonstrates decreasing Medicare reimbursement to physicians within hip and knee arthroplasty from 2000 to 2019 when adjusting for inflation. This study is important for informing the potential development of more equitable payment models and maintaining access for arthroplasty care moving forward.

Is It Worth Delaying Total Knee Replacement as Late as Possible? A Cost-Effectiveness Analysis Using a Markov Model in the Indian Setting

BACKGROUND

Total knee replacement (TKR) is often delayed in younger patients in an attempt to prolong the longevity of the prosthesis and avoid the risk of revision. But delaying a TKR might compromise the quality of life of young patients who are otherwise active and healthy.

METHODS

We built a Markov decision model to study the simulated clinical course of a 50-year-old patient with severe unilateral knee osteoarthritis who could be either treated with conservative therapies or with a TKR at some point in time. An Indian healthcare payer perspective model was used, and lifetime costs (in Indian rupees), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were calculated.

RESULTS

In the base case scenario, patients who did not receive a TKR had a total lifetime cost of ₹216 709 and accumulated 13.59 QALYS in their lifetime. Those who received a TKR without delay (at age 50) accumulated 16.71 QALYS in their lifetime with an ICER of ₹9789 per QALY. When TKR was delayed, the total QALYs decreased, and ICER increased with each year of delay. But the cumulative risk of revision decreased from 27.4% when TKR was performed at 50 years to 10.0% when TKR was done at 70 years.

CONCLUSION

Our analysis found that TKR is a cost-effective procedure when the healthcare payer is willing to pay at least ₹9789 ($132) per QALY. The results also suggested that an early TKR is preferred to a delayed TKR despite the higher incidence of revisions.

Hospital and Surgeon Medicare Reimbursement Trends for Total Joint Arthroplasty

BACKGROUND

Over 1 million total joint arthroplasties (TJAs) are performed every year in the United States, creating Medicare cost concerns for policy makers. The purpose of this study is to evaluate recent trends in Medicare utilization and reimbursements to hospitals/surgeons for TJAs between 2012 and 2017.

METHODS

We tracked annual Medicare claims and payments to TJA surgeons using publicly available Medicare databases and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization (per 10,000 Medicare beneficiaries), and reimbursement rates and to examine associations between county-specific variables and TJA utilization and reimbursements.

RESULTS

Between 2012 and 2017, there was an 18.9% increase in annual primary TJA volume (357,500 cases in 2012 to 425,028 cases in 2017) and a 2.0% increase in annual primary TJA per capita utilization (73.4 cases per 10,000 Medicare beneficiaries in 2012 to 74.8 in 2017). The Midwest and the South had higher utilization rates compared with the Northeast and West (P < .001). Utilization rates for primary TJA procedures also had a significant negative association with the poverty rate (P < .001). Medicare Part B payments to surgeons fell by 7.5%, equivalent to a 14.9% inflation-adjusted decline, whereas hospital reimbursements and charges increased by 0.3% and 18.6%, respectively, during the study period.

CONCLUSIONS

Despite increasing TJA volume and utilization, surgeon reimbursements have continued to decline, whereas hospital payments and hospital charges have increased significantly more than surgeon charges. Cost containment efforts will need to address other expenditures such as hospital costs and implant costs to better align financial risks and incentives for TJA surgeons.

Patient characteristics and valuation changes impact quality of life and satisfaction in total knee arthroplasty - results from a German prospective cohort study

Background

Evaluation of variations in pre- and postoperative patient reported outcomes (PRO) and the association between preoperative patient characteristics and health and satisfaction outcomes after total knee arthroplasty (TKA) may support shared decision-making in Germany. Since previous research on TKA health outcomes indicated valuation differences in longitudinal data, experienced-based population weights were used for the first time as an external valuation system to measure discrepancies between patient and average population valuation of HRQoL.

Methods

Baseline data (n = 203) included sociodemographic and clinical characteristics and PROs, measured by the EQ-5D-3 L and WOMAC. Six-month follow-up data (n = 161) included medical changes since hospital discharge, PROs and satisfaction. A multivariate linear regression analysis was performed to evaluate the relationship between preoperative patient characteristics and PRO scores. Patient acceptable symptom state (PASS) was calculated to provide a satisfaction threshold. Patient-reported health-related quality of life (HRQoL) valuations were compared with average experienced-based population values to detect changes in valuation.

Results

One hundred thirty-seven subjects met inclusion criteria. All PRO measures improved significantly. Preoperative WOMAC and EQ-5D VAS, housing situation, marital status, age and asthma were found to be predictors of postoperative outcomes. 73% of study participants valued their preoperative HRQoL higher than the general population valuation, indicating response shift. Preoperatively, patient-reported EQ-5D VAS was substantially higher than average experienced-based population values. Postoperatively, this difference declined sharply.

Approximately 61% of the patients reported satisfactory postoperative health, being mainly satisfied with results if postoperative WOMAC was ≥82.49 (change ≥20.25) and postoperative EQ-5D VAS was ≥75 (change ≥6).

Conclusion

On average, patients benefited from TKA. Preoperative WOMAC and EQ-5D VAS were predictors of postoperative outcomes after TKA. Particularly patients with high absolute preoperative PRO scores were more likely to remain unsatisfied. Therefore, outcome prediction can contribute to shared-decision making. Using general population valuations as a reference, this study underlined a discrepancy between population and patient valuation of HRQoL before, but not after surgery, thus indicating a potential temporary response shift before surgery.

Demographic and geographical variability in physiotherapy provision following hip and knee replacement. An analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

Total hip (THR) and knee replacement (TKR) are two of the most common elective orthopaedic procedures worldwide. Physiotherapy is core to the recovery of people following joint replacement. However, there remains uncertainty as to physiotherapy provision at a national level.

OBJECTIVES

To examine the relationship between patient impairment and geographical variation on the provision of physiotherapy among patients who undergo primary total hip or knee replacement (THR/TKR).

DESIGN

Population-based observational cohort study.

METHODS

Patients undergoing THR (n=17,338) or TKR (n=20,260) recorded in the National Joint Registry for England (NJR) between 2009 and 2010 and completed Patient Reported Outcome Measures (PROMs) questionnaires at Baseline and 12 months postoperatively. Data were analysed on the frequency of physiotherapy over the first postoperative year across England's Strategic Health Authorities (SHAs). Logistic regression analyses examined the relationship between a range of patient and geographical characteristics and physiotherapy provision.

RESULTS

Following THR, patients were less likely to receive physiotherapy than following TKR patients ('some' treatment by a physiotherapist within 1st post operative year: 53% vs 79%). People with worse functional outcomes 12 months postoperatively, received more physiotherapy after THR and TKR. There was substantial variation in provision of physiotherapy according to age (younger people received more physiotherapy), gender (females received more physiotherapy) ethnicity (non-whites received more physiotherapy) and geographical location (40% of patients from South West received some physiotherapy compared to 40 73% in London after THR).

CONCLUSIONS

There is substantial variation in the provision of physiotherapy nationally. This variation is not explained by differences in the patient's clinical presentation.

Cost-utility analysis of total knee arthroplasty for osteoarthritis in a regional medical center in China

BACKGROUND

To analyze the cost-effective ratio of total knee arthroplasty (TKA) in the osteoarthritis (OA) treatment of at a regional medical center in China.

METHODS

One hundred thirty-nine patients with osteoarthritis who underwent TKA at the Department of Osteoarthritis in Luhe hospital (Tongzhou, Beijing) from January 2011 to January 2012 were followed up. Their health-related quality of life (HRQoL) was evaluated using Short-Form Health Survey (SF) -36 Chinese version, and compared with those of the normal population to assess quality-adjusted life years (QALYs) gained after surgery for its effectiveness of the treatment. The total expense was the cost of patient hospitalization. The cost per QALY was calculated. The cost-benefit ratio (CBR) was expressed as a ratio of each QALY's expenditure to per capita gross domestic product (GDP). Factors affecting the cost, including age, gender, length of stay, and ICU experience, were also considered.

RESULTS

The total hospitalization fee was Ұ8,053,736.68, Ұ57,940.55 in average, of which, 81.59% constituted out-of-pocket expenses. The SF-36 scores were as follows: Physical Function: 25.14, Role Physical: 7.12, Bodily Pain: 9.60, Role emotional: 5.58, Vitality: 19.9, Mental Health: 25.84, Social Function: 9.86 and General Health: 21.15. Compared with normal people of the same age and sex, a total of Ұ2487.74 QALYs and Ұ3237.37/QALY were gained, 10% less than the regional GDP per capita. The cost-effective ratio of TKA for osteoarthritis in China was 1: 10.78. The main cost of the patient was the cost of prosthesis (61.78%). The average cost afforded by patients' themselves was Ұ47,242.64 after the deduction of government subsidies. There were Ұ31,306.64 difference compared with the annual average income of the local people. The cost might be affected by length of stay and ICU experience. Longer stay caused more cost of treatment. Patients who remained in ICU after surgery had higher overall costs and blood transfusion costs.

CONCLUSION

The factors that affect TKA cost are hospital and postsurgical ICU stay. It is cost-effective for regional medical care center to treat osteoarthritis using TKA economically. However, considering the average income of patients in the area, it is necessary to reduce the cost of the treatment.

Local Cellular Responses to Titanium Dioxide from Orthopedic Implants

We evaluated recently published articles relevant to the biological effects of titanium dioxide (TiO₂) particles on local endogenous cells required for normal bone homeostasis, repair, and implant osseointegration. Structural characteristics, size, stability, and agglomeration of TiO₂ particles alter the viability and behavior of multiple bone-related cell types. Resulting shifts in bone homeostasis may increase bone resorption and lead to clinical incidents of osteolysis, implant loosening, and joint pain. TiO₂ particles that enter cells (through endocytosis or Trojan horse mechanism) may further disrupt implant retention. We propose that cellular responses to titanium-based nanoparticles contribute to pathological mechanisms underlying the aseptic loosening of titanium-based metal implants.

Total Knee Arthroplasty for Knee Osteoarthritis: Support for a Foregone Conclusion?

Total knee arthroplasty (TKA) is generally accepted as the definitive treatment for advanced knee arthritis after patients fail nonoperative treatments; however, the safety and efficacy of TKA compared to continued nonoperative treatment has never been proven in high-quality, randomized controlled trials. Recently, a 2015 Danish study published a 12-month follow-up on a cohort of patients randomized to either a TKA or continued nonsurgical management for advanced knee osteoarthritis (OA). The authors reported significantly greater improvement in the TKA group in functional outcome scores such as the overall Knee Injury and Osteoarthritis Outcome Score (KOOS₄ score), the KOOS subscales, EQ-5D descriptive index, and timed get up-and-go and 20-m walk tests; however, patients in the TKA did suffer significantly more serious adverse events (SAE). The authors concluded that TKA combined with additional nonoperative care postoperatively is more efficacious than nonsurgical treatment alone in terms of improving pain, function, and quality of life at 12 months but is associated with more SAE. The purpose of this review is to identify the strengths and weaknesses of this trial, interpret its outcomes within the context of prior literature, and evaluate the validity of its conclusions.

Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

BACKGROUND

The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available.

QUESTIONS/PURPOSES

A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department's perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations.

METHODS

A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department's perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes.

RESULTS

Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p <.001). On the level of the separate hospitalizations the mean direct costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they differ significantly (p <.001). Major cost drivers were the cost of the implant and general staff. The septic implantation part was on average $3,142.87 more expensive than septic explantations (p <.001).

CONCLUSIONS

Our study for the first time provides a detailed analysis of the major direct case costs of aseptic and septic revision TKA from the hospital-department's perspective which is the basis for long-term orientated decision making. In the future, our cost analysis has to be interpreted in relation to reimbursement estimates. This is important to check whether revision TKA lead to a financial loss for the operating department.

Surgically modifiable factors measured by computer-navigation together with patient-specific factors predict knee society score after total knee arthroplasty

BACKGROUND

The purpose was to investigate whether patient-specific factors (PSF) and surgically modifiable factors (SMF), measured by means of a computer-assisted navigation system, can predict the Knee Society Scores (KSS) after total knee arthroplasty (TKA).

METHODS

Data from 99 patients collected during a randomized clinical trial were used for this secondary data analysis. The KSS scores of the patients were measured preoperatively and at 4-years follow-up. Multiple regression analyses were performed to investigate which combination of variables would be the best to predict the 4-years KSS scores.

RESULTS

When considering SMF alone the combination of four of them significantly predicted the 4-years KSS-F score (p = 0.009), explaining 18 % of its variation. When considering only PSF the combination of age and body weight significantly predicted the 4-years KSS-F (p = 0.008), explaining 11 % of its variation. When considering both groups of predictors simultaneously the combination of three PSF and two SMF significantly predicted the 4-years KSS-F (p = 0.007), explaining 20 % of its variation.

CONCLUSIONS

Younger age, better preoperative KSS-F scores and lower BMI before surgery, a positive tibial component slope and small changes in femoral offset were predictors of better KSS-F scores at 4-years.

Does intramedullary canal irrigation reduce fat emboli? A randomized clinical trial with transesophageal echocardiography

The effect of medullary cavity irrigation on fat emboli during total knee arthroplasty (TKA) was evaluated. Thirty female patients with osteoarthritis were randomly assigned to undergo conventional TKA without irrigation (conventional group) or with medullary canal saline irrigation (irrigation group). The four-chamber view was monitored by transesophageal echocardiography (TEE) and echogenic reflections of fat emboli were observed. The grey-scale score and area ratio of fat emboli were calculated during TKA. Hemodynamic parameters were simultaneously monitored and showed no obvious change between two groups (P>0.05). The average grey-scale score (P=0.016) and area ratio (P=0.033) of emboli were significantly decreased in irrigation group. Removal of medullary contents by irrigation could significantly reduce the formation of fat emboli during TKA.

An 8-Week Knee Osteoarthritis Treatment Program of Hyaluronic Acid Injection, Deliberate Physical Rehabilitation, and Patient Education is Cost Effective at 2 Years Follow-up: The OsteoArthritis Centers of America(SM) Experience

Numerous nonsurgical interventions have been reported to improve symptoms of knee osteoarthritis (OA) over the short term. However, longer follow-up is required to accurately characterize outcomes such as cost effectiveness and delayed arthroplasty. A total of 553 patients with symptomatic knee OA who previously underwent a single 8-week multimodal treatment program were contacted at 1 year (n = 336) or 2 years (n = 217) follow-up. The percentage of patients who underwent knee arthroplasty was 10% at 1 year and 18% at 2 years following program completion. The treatment program was highly cost effective at $12,800 per quality-adjusted life year at 2 years. Cost effectiveness was maintained under a variety of plausible assumptions and regardless of gender, age, body mass index, disease severity, or knee pain severity. In summary, a single 8-week multimodal knee OA treatment program is cost effective and may lower knee arthroplasty utilization through 2 years follow-up.

Descriptive analysis of the cost-effectiveness of depressed patients undergoing total knee arthroplasty: an economic decision analysis

BACKGROUND

Recent rising concern about the cost-effectiveness ratio of total knee arthroplasty (TKA) led us to evaluate this successful procedure from the economic perspective, thereby helping policy-makers to conduct medical resource allocation more effectively and efficiently. However, up to now no study has investigated the influence of patients' psychological factors on their evaluation of TKA's cost-effectiveness. Therefore, we decided to determine whether and how depression, which is a common negative psychological factor in the population undergoing TKA, affects their economic evaluation of the procedure.

METHODS

A total of 312 patients who had undergone TKA were graded into three groups based on the level of depression measured by the Center for Epidemiological Studies Depression Scale (CES-D) scores. Clinical effectiveness information was obtained using the WOMAC questionnaire; total costs related to TKA were acquired through interviews with patients and review of their medical records in the computing system.

RESULTS

Patients with high-level depression (3491.9$/QALYS; 95% CI, 3471.1-3491.9$/QALYS) had greater cost-effectiveness compared tothose with low-level (2447.1$/QALYS; 95% CI, 2427.9-2466.3$/QALYS) and middle-level (3027.2$/QALYS; 95% CI, 3011.0-3043.4$/QALYS) depression. We concluded there was a significant positive correlation between cost-effectiveness and the level of depression after TKA (r = 0.703, P = 0.014). Significant differences in the costs of hospital stay, medical treatment, rehabilitation, and outpatient care were detected among the three groups.

CONCLUSIONS

Our study might help policy-makers and clinicians identify which types of patients benefit most from TKA and then advise high-risk patients (high-level depression status in this study) about how to recovery better with limited resource allocation. Preoperative evaluation of patients' psychological state may decrease unnecessary economic burdens and suffering during the recovery period.

A prospective study of the association of patient expectations with changes in health-related quality of life outcomes, following total joint replacement

BACKGROUND

Patient expectations regarding surgery may be related to outcomes in total joint replacement (TJR). The aim of this study was to determine the association of patient expectations with health related quality of life (HRQoL) outcomes measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short Form 12 (SF-12) and satisfaction with current symptoms measured on a 4-point Likert scale, one year after surgery, adjusting for Body Mass Index (BMI), age, gender, joint, education, previous intervention and baseline scores.

METHODS

Consecutive patients preparing for TJR of the knee or hip due to primary osteoarthritis (OA) in 15 hospitals in Spain were recruited for the study. Patients completed questionnaires before surgery and 12 months afterwards: five questions about expectations before surgery; an item to measure satisfaction; two HRQoL instruments-WOMAC and SF-12; as well as questions about sociodemographic information. To determine the association of patient expectations at baseline, with changes in HRQoL 12 months after surgery and with satisfaction, general linear models and logistic regression analysis were performed.

RESULTS

A total of 892 patients took part in the study. Patients who had higher pain relief or ability to walk expectations improved more in HRQoL at 12 months. Moreover, patients with high daily activity expectations were more satisfied.

CONCLUSIONS

Patients with higher baseline expectations for TJR, improved more in HRQoL at one year and had more likelihood to be satisfied than patients with lower expectations, adjusted for BMI, age, gender, joint, education, previous intervention and HRQoL baseline scores.

Progressive resistance training before and after total hip and knee arthroplasty: a systematic review

OBJECTIVE

To investigate the effect of progressive resistance training (PRT) on muscle strength and functional capacity before and/or after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The effects of THA and TKA upon quality of life and the rate of adverse events were also investigated.

DATA SOURCES

Literature from nine databases.

REVIEW METHODS

Studies were included if 1) the effect of a PRT intervention was compared with no intervention or another type of intervention; 2) the outcomes included muscle strength and/or functional capacity; 3) all participants were scheduled for or had just undergone THA or TKA; 4) they were randomized, controlled trials (RCT); and 5) only full-length papers in English were studied. Data on patient characteristics, training regime, controls, and outcome measures were extracted.

RESULTS

Four RCT studies on PRT and THA including 136 patients and three RCT studies on PRT and TKA including 284 patients were identified and rated according to the PEDro scale. The general methodological quality of the studies was low. No adverse events were reported in any of the studies. Weak evidence of a beneficial effect of PRT before and/or after THA on muscle strength and functional capacity was found. No effect of PRT before TKA on muscle strength and functional capacity was found. The results of postoperative PRT were too heterogeneous to allow conclusions.

CONCLUSION

PRT is safe and feasible before and/or after THA. PRT is safe, but the methodological quality of existing evidence permits no conclusion on the effectiveness of PRT before and/or after TKA.

Creep of trabecular bone from the human proximal tibia

Creep is the deformation that occurs under a prolonged, sustained load and can lead to permanent damage in bone. Creep in bone is a complex phenomenon and varies with type of loading and local mechanical properties. Human trabecular bone samples from proximal tibia were harvested from a 71-year old female cadaver with osteoporosis. The samples were initially subjected to one cycle load up to 1% strain to determine the creep load. Samples were then loaded in compression under a constant stress for 2h and immediately unloaded. All tests were conducted with the specimens soaked in phosphate buffered saline with proteinase inhibitors at 37 °C. Steady state creep rate and final creep strain were estimated from mechanical testing and compared with published data. The steady state creep rate correlated well with values obtained from bovine tibial and human vertebral trabecular bone, and was higher for lower density samples. Tissue architecture was analyzed by micro-computed tomography (μCT) both before and after creep testing to assess creep deformation and damage accumulated. Quantitative morphometric analysis indicated that creep induced changes in trabecular separation and the structural model index. A main mode of deformation was bending of trabeculae.

An economic analysis of aseptic revision hip arthroplasty: calculation of partial hospital costs in relation to reimbursement

INTRODUCTION

Aseptic loosening is one of the most common intermediate and long-term complications after total hip replacement (THR). These complications cause suffering and require expensive revision surgery. Little concrete data on direct costs are available from the hospital's, moreover operating department's perspective. We here provide a detailed analysis of the costs of THR revision and relate them to reimbursement underlying the German diagnosis-related groups (DRG) system.

MATERIALS AND METHODS

Major cost parameters were identified using for orientation the cost matrix of the German Institute for Hospital Reimbursement (InEK GmbH). We then retrospectively analysed the major direct costs of aseptic revision THR in terms of contribution margins I and II. The analysis included a total of 114 patients who underwent aseptic revision from 1 January 2009 to 31 March 2012. Data were retrieved from the hospital information system and patient records. All costs of surgery, diagnostic tests, and other treatments were calculated as purchase prices in EUR. The comparative analysis of direct costs and reimbursements was done for DRG I46A and I46B from the hospital's, especially treating department's rather than the society or healthcare insurance's perspective.

RESULTS

The average direct cost incurred by the hospital for a THR revision was <euro>4,380.0. The largest share was accounted for surgical costs (62.7 % of total). Implant and staff costs were identified as the most important factors that can be influenced. The proportion of the daily contribution margin that was left to cover the hospital's indirect cost decreased with the relative cost weight of the DRG to which a patient was assigned.

CONCLUSION

Our study for the first time provides a detailed analysis of the major direct case costs of THR revision for aseptic loosening from the provider's perspective. Our findings suggest that these revision operations could be performed cost-beneficially by the operating unit. From an economic perspective, cases with higher cost weights are more favorable for a hospital. These results need to be confirmed in multicenter studies.

Cost-effectiveness and economic impact of the KineSpring ® Knee Implant System in the treatment for knee osteoarthritis

PURPOSE

To investigate the cost-effectiveness and economic impact of the KineSpring System in the treatment for knee osteoarthritis in Germany.

METHODS

Functional outcome scores of the general German population and knee osteoarthritis (OA) patients under surgical treatments (HTO, UKA and TKA), conservative treatments and treatment with the KineSpring System were used to derive the utility scores for each group. Quality-adjusted life years (QALYs) of each group were estimated using the utility scores. Finally, cost-utility analysis was performed using cost and QALYs data. The economic impact of knee OA in Germany was assessed in terms of annual total direct cost and indirect cost, total diseased population and potential QALYs saved with the KineSpring System.

RESULTS

Assuming the durability of 10 years, the cost-utility ratio of the KineSpring System, surgical treatments and conservative treatments compared to no treatment in 2012 was euro>3,402/QALY, euro 4,899/QALY and euro 9,996/QALY, respectively. With even a lesser durability of 5 years, the cost-utility ratio of the KineSpring System maintained superiority over surgical treatments and conservative treatments (euro 7,327/QALY, euro 9,706/QALY and euro 10,467/QALY, respectively). The KineSpring System is a highly cost-effective alternative for knee osteoarthritis compared with the current accepted cost-effective threshold (willingness to pay) of $50,000 US/QALY gained. Our models suggest KineSpring System, if adapted widely could save up to 2.0 ± 0.07 million QALY assuming it has a 5-year durability and save up to 3.9 ± 0.1 million QALY assuming it has a 10-year durability.

CONCLUSION

An economic advantage for using the KineSpring System over other surgical and conservative treatments in knee OA patients in Germany is suggested by our model. According to currently accepted cost-effectiveness guidelines, the KineSpring Knee Implant System for knee OA is a cost-effective strategy.

Is a diabetes pay-for-performance program cost-effective under the National Health Insurance in Taiwan?

PURPOSE

In October 2001, a pay-for-performance (P4P) program for diabetes was implemented by the National Health Insurance (NHI), a single-payer program, in Taiwan. However, only limited information is available regarding the influence of this program on the patient's health-related quality of life. The aim of this study was to estimate the costs and consequences of enrolling patients in the P4P program from a single-payer perspective.

METHODS

A retrospective observational study of 529 diabetic patients was conducted between 2004 and 2005. The data used in the study were obtained from the National Health Interview Survey (NHIS) in Taiwan. Direct cost data were obtained from NHI claims data, which were linked to respondents in the NHIS using scrambled individual identification. The generic SF36 health instrument was employed to measure the quality-of-life-related health status and transformed into a utility index. Patients enrolled in the P4P program for at least 3 months were categorized as the P4P group. Following propensity score matching, 260 patients were included in the study. Outcomes included life-years, quality-adjusted life-years (QALYs), diabetes-related medical costs, overall medical costs, and incremental cost-effectiveness ratios (ICERs). A single-payer perspective was assumed, and costs were expressed in US dollars. Nonparametric bootstrapping was conducted to estimate confidence intervals for cost-effectiveness ratios.

RESULTS

Following matching, no significant difference was noted between two groups with regard to the patients' age, gender, education, family income, smoking status, BMI, or whether insulin was used. The P4P group had an increase of 0.08 (95 % CI 0.077-0.080) in QALYs, and the additional diabetes-related medical cost was US$422.74 (95 % CI US$413.58-US$435.05), yielding an ICER of US$5413.93 (95 % CI US$5226.83-US$5562.97) per QALY gained.

CONCLUSIONS

Our results provides decision makers with valuable information regarding the impact of the P4P program of diabetes care through a direct comparison of equivalent groups of patients receiving regular care. Under the single-payer NHI system, the use of financial incentives under the DM-P4P program may be an effective means to ensure the quality of follow-up treatment.

The cost-effectiveness of total joint arthroplasty: a systematic review of published literature

OBJECTIVE

To summarise the state of the literature evaluating the cost-effectiveness of elective total hip and knee arthroplasty (THA and TKA).

METHODS

We conducted a systematic review of published cost-effectiveness analyses of THA and TKA. To limit our search to high-quality published papers, we selected those papers included in the Cost-Effectiveness Analysis Registry (created by the Center for the Evaluation of Value and Risk in Health at Tufts University) and augmented the search with papers listed in PubMed. The data abstracted included incremental cost-effectiveness ratios, perspective of the analysis, time frame, sensitivity analyses conducted, and utility assessment. All cost-effectiveness ratios were converted to 2011 USD.

RESULTS

Seven studies presenting cost-effectiveness ratios for TKA and six studies for THA were included in our review. All economic evaluations of TKA were published between 2006 and 2012. By contrast, THA studies were published between 1996 and 2008. Out of the 13 studies evaluated in this review, four were from the societal perspective and eight were from the payer perspective. Five studies spanned the lifetime horizon. Of the selected studies, six used probabilistic sensitivity analysis to address uncertainty in data parameters. Both procedures have been shown to be highly cost-effective from the societal perspective over the entire lifespan.

CONCLUSION

THA and TKA have been found to be highly cost-effective in a number of high-quality studies. Further analyses are needed on the cost-effectiveness of alternative surgical options, particularly osteotomy. Future economic evaluations should address the expanding indications of THA and TKA to younger, more physically active individuals.

Assessing the value of a total joint replacement

Total joint arthroplasty (TJA) continues to be one of the most successful surgical interventions in medicine. Demand is growing rapidly, placing an increasingly heavy cost burden on national health systems. Despite the popularity of these surgeries, high-quality cost-effectiveness studies evaluating TJA are few in number. This article summarizes the current literature on value in arthroplasty, identifying the various factors affecting costs and outcomes, and suggesting how policy makers can influence utilization of TJA to further improve value to society.

Total knee arthroplasty volume, utilization, and outcomes among Medicare beneficiaries, 1991-2010

CONTEXT

Total knee arthroplasty (TKA) is one of the most common and costly surgical procedures performed in the United States.

OBJECTIVE

To examine longitudinal trends in volume, utilization, and outcomes for primary and revision TKA between 1991 and 2010 in the US Medicare population.

DESIGN, SETTING, AND PARTICIPANTS

Observational cohort of 3,271,851 patients (aged ≥65 years) who underwent primary TKA and 318 563 who underwent revision TKA identified in Medicare Part A data files.

MAIN OUTCOME MEASURES

We examined changes in primary and revision TKA volume, per capita utilization, hospital length of stay (LOS), readmission rates, and adverse outcomes.

RESULTS

Between 1991 and 2010 annual primary TKA volume increased 161.5% from 93,230 to 243,802 while per capita utilization increased 99.2% (from 31.2 procedures per 10,000 Medicare enrollees in 1991 to 62.1 procedures per 10,000 in 2010). Revision TKA volume increased 105.9% from 9650 to 19,871 while per capita utilization increased 59.4% (from 3.2 procedures per 10,000 Medicare enrollees in 1991 to 5.1 procedures per 10,000 in 2010). For primary TKA, LOS decreased from 7.9 days (95% CI, 7.8-7.9) in 1991-1994 to 3.5 days (95% CI, 3.5-3.5) in 2007-2010 (P < .001). For primary TKA, rates of adverse outcomes resulting in readmission remained stable between 1991-2010, but rates of all-cause 30-day readmission increased from 4.2% (95% CI, 4.1%-4.2%) to 5.0% (95% CI, 4.9%-5.0%) (P < .001). For revision TKA, the decrease in hospital LOS was accompanied by an increase in all-cause 30-day readmission from 6.1% (95% CI, 5.9%-6.4%) to 8.9% (95% CI, 8.7%-9.2%) (P < .001) and an increase in readmission for wound infection from 1.4% (95% CI, 1.3%-1.5%) to 3.0% (95% CI, 2.9%-3.1%) (P < .001).

CONCLUSIONS

Increases in TKA volume have been driven by both increases in the number of Medicare enrollees and in per capita utilization. We also observed decreases in hospital LOS that were accompanied by increases in hospital readmission rates.

Clinical and economic consequences of the treatment gap in knee osteoarthritis management

Osteoarthritis affects 27 million American adults of all ages and is a leading cause of disability in middle-aged and older adults. Initial management of knee osteoarthritis symptoms utilizes conservative care although long-term efficacy is poor. Arthroplasty and high tibial osteotomy may be considered for patients with severe pain or disability. We hypothesize that a distinct treatment gap exists for the patient with symptomatic knee osteoarthritis who is unresponsive to conservative care (including simple surgical treatments) yet refuses to undergo or is not an appropriate candidate for more invasive surgical procedures. This treatment gap represents a protracted period in which the patient experiences debilitating pain, reduced quality of life, and a significant financial burden. Approximately 3.6 million Americans linger in the knee osteoarthritis treatment gap and this number will grow to about 5 million people by 2025. The typical knee osteoarthritis treatment gap extends 20 years although the younger osteoarthritis patient is faced with the treatment gap throughout the majority of their adult life. There is great need for a safe, effective, and cost effective treatment option for patients with moderate to severe osteoarthritis that enjoys high patient acceptance.

International survey of primary and revision total knee replacement

PURPOSE

Total knee arthroplasty (TKA) is currently the international standard of care for treating degenerative and rheumatologic knee joint disease, as well as certain knee joint fractures. We sought to answer the following three research questions: (1) What is the international variance in primary and revision TKA rates around the world? (2) How do patient demographics (e.g., age, gender) vary internationally? (3) How have the rates of TKA utilization changed over time?

METHODS

The survey included 18 countries with a total population of 755 million, and an estimated 1,324,000 annual primary and revision total knee procedures. Ten national inpatient databases were queried for this study from Canada, the United States, Finland, France, Germany, Italy, the Netherlands, Portugal, Spain, and Switzerland. Inpatient data were also compared with published registry data for eight countries with operating arthroplasty registers (Denmark, England & Wales, Norway, Romania, Scotland, Sweden, Australia, and New Zealand).

RESULTS

The average and median rate of primary and revision (combined) total knee replacement was 175 and 149 procedures/100,000 population, respectively, and ranged between 8.8 and 234 procedures/100,000 population. We observed that the procedure rate significantly increased over time for the countries in which historical data were available. The compound annual growth in the incidence of TKA ranged by country from 5.3% (France) to 17% (Portugal). We observed a nearly 27-fold range of TKA utilization rates between the 18 different countries included in the survey.

CONCLUSION

It is apparent from the results of this study that the demand for TKA has risen substantially over the past decade in countries around the world.

Evaluation of health outcomes in osteoarthritis patients after total knee replacement: a two-year follow-up

Objectives

To quantify the improvement in health outcomes in patients after total knee replacement (TKR).

Methods

This was a two-year non-randomized prospective observational study in knee osteoarthritis (OA) patients undergone TKR. Patients were interviewed one week before, six months after, and two years after surgery using a standardized questionnaire including the SF-36, the Oxford Knee Score (OKS), and the Knee Society Clinical Rating Scale (KSS). A generalized estimating equation (GEE) model was used to estimate the magnitudes of the changes with and without the adjustment of age, ethnicity, BMI, and years with OA.

Results

A total of 298 (at baseline), 176 (at six-months), and 111 (at two-years) eligible patients were included in the analyses. All the scores changed significantly over time, with the exception of SF-36 social functioning, vitality, and mental health. With the adjustment of covariates, the magnitude of changes in these scores was similar to those without the adjustment.

Conclusions

Both general and knee-specific physical functioning had been significantly improved after TKR, while other health domains have not been substantially improved after the surgery.

Patient expectations and health-related quality of life outcomes following total joint replacement

OBJECTIVES

Patient psychological factors have been linked to health-related quality of life (HRQoL) outcomes after total joint replacement (TJR). We evaluated the relationship between patient expectations before TJR, their fulfillment and HRQoL outcomes at 3 and 12 months after surgery.

METHODS

Consecutive patients preparing for TJR of the knee or hip due to primary osteoarthritis in 15 hospitals in Spain were recruited for the study. Patients completed questionnaires before surgery, and 3 and 12 months afterward: five questions about expectations before surgery and their fulfillment at 3 and 12 months; three HRQoL instruments-Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form 12 (SF-12), and European Quality of Life Instrument (EQ-5D); as well as questions about sociodemographic information. Student's t test was used to assess the relationship between fulfillment of expectations and gains in HRQoL.

RESULTS

A total of 881 patients took part in the study. Preintervention expectations for TJR ranged from 85% to 86% of patients, with high expectations for pain relief and ability to walk to 70% with high expectations about interacting with others. Patients who reported having fulfilled their expectations at 3 and 12 months had significantly greater gains in HRQoL than those who did not. Besides, we observed a statistically significant improvement in the percentage of patients who fulfill their expectations from 3 to 12 months.

CONCLUSIONS

Patients have high expectations for the benefits of TJR, and those who fulfill their expectations have greater gains in HRQoL assessing by SF-12, WOMAC and EQ-5D. Health-care providers should help their patients develop realistic expectations about the impact of TJR.