Conversion Total Knee Arthroplasty is Associated with Increased Post-Acute Care Costs

BackgroundAlternative payment models have been viewed as successfully decreasing costs following primary total knee arthroplasty (TKA) while maintaining quality. Concerns exist regarding access to care for patients who may utilize more resources in a bundled payment arrangement. The purpose of this study is to determine if patients undergoing conversion of prior surgery to TKA have increased costs compared to primary TKA patients.MethodsClaims from Medicare and a single private insurer were queried for all primary TKA patients at our institution from 2015 to 2016. Ninety-day post-acute care costs were compared between primary and conversion TKA. Secondary endpoints included discharge disposition, complications, and readmissions. A multivariate regression analysis was performed to identify independent risk factors for increased post-acute care costs and short-term outcome metrics.ResultsOf 3999 primary TKA procedures, 948 patients (23%) underwent conversion TKA. Conversion TKA was associated with greater post-acute care costs in patients with commercial insurance ($4714 vs $3759, P = .034). Among Medicare beneficiaries, prior ligament reconstruction was associated with increased post-acute care costs ($1917 increase, P = .036), while prior fracture fixation approached statistical significance ($2402 increase, P = .055). Conversion TKA was an independent risk factor for readmissions (odds ratio 1.46, 95% confidence interval 1.00-2.17, P = .050), while patients with a prior open knee procedure had higher rates of complications (odds ratio 2.41, 95% confidence interval 1.004-5.778, P = .049).ConclusionOur data suggest that conversion from prior knee surgery to TKA is associated with increased 90-day post-acute care costs and resource utilization, particularly prior open procedures. Without appropriate risk adjustment in alternative payment models, surgeons may be financially deterred from providing quality arthroplasty care given the reduced net payment and surgical complexity of such cases.     

The Use of Cementless Components Does Not Significantly Increase Procedural Costs in Total Knee Arthroplasty

BackgroundModern cementless total knee arthroplasty (TKA) designs have shown promising early clinical success; however, concerns exist regarding the higher cost of the cementless implants. The purpose of this study is to evaluate the total facility cost of cementless vs traditional cemented TKA along with the effect of cementless fixation on short-term outcomes.MethodsWe reviewed a consecutive series of patients between 2015 and 2017 who underwent either cementless or cemented primary TKA. Itemized facility costs were calculated for every procedure using a time-driven activity-based costing algorithm. Controlling for demographic variables and medical comorbidities, we performed a multivariate analysis to identify independent risk factors for facility costs following TKA. Short-term outcome metrics including complications, readmissions, and patient-reported outcomes were compared between groups.ResultsAmong the 2426 primary TKA patients in this study, 119 (4.91%) were performed using cementless implants. When compared to cemented TKA, cementless TKA patients had higher implant costs ($3047.80 vs $2808.73, P < .0001), but lower supply costs ($639.49 vs $815.57, P < .0001) and lower operating room personnel costs ($982.01 vs $1238.26, P < .0001). When controlling for confounding variables, cementless fixation did not have a significant effect on total facility cost or outcomes.ConclusionIn conclusion, the use of cementless TKA implants did not significantly increase total procedural costs when compared to traditional cemented TKA components at our institution. Our data suggest that the increased cost of a cementless implant is recouped through savings in cost of cement and supplies, as well as shorter operative times. The authors encourage investigators at other institutions to use the authors' methodology to evaluate (preferably in a prospective manner) whether the findings from this study can be corroborated.     

The Economics of Antibiotic Cement in Total Knee Arthroplasty: Added Cost with No Reduction in Infection Rates

BackgroundTo reduce the substantial clinical and financial burden of periprosthetic joint infection (PJI), some surgeons advocate for the use of antibiotic-loaded bone cement (ALBC) in primary total knee arthroplasty (TKA), although its effectiveness continues to be debated in the literature. The purpose of this study was to determine whether the routine use of ALBC is cost-effective in reducing PJI after primary TKA.MethodsWe retrospectively reviewed a consecutive series of patients undergoing cemented primary TKA at two hospitals within our institution from 2015 to 2017. We compared demographics, comorbidities, costs, and PJI rates between patients receiving ALBC and plain cement. We performed a multivariate regression analysis to determine the independent effect of ALBC on PJI rate. We calculated readmission costs for PJI and reduction in PJI needed to justify the added cost of ALBC.ResultsOf 2511 patients, 1077 underwent TKA with ALBC (43%), with no difference in PJI rates (0.56% vs 0.14%, P = .0662) or complications (1.2% vs 1.6%, P = .3968) but higher cement costs ($416 vs $117, P < .0001) and overall procedure costs ($6445 vs $5.968, P < .0001). ALBC had no effect on infection rate (P = .0894). Patients readmitted with PJI had higher overall 90-day episode-of-care claims costs ($49,341 vs $19,032, P < .001). To justify additional costs, ALBC would need to prevent infection in one of every 101 patients.ConclusionRoutine use of ALBC in primary TKA is not cost-effective, adding $299 to the cost of episode of care without a reduction in PJI rate. Further study is needed to determine whether select use of ALBC would be justified in high-risk patients.     

A Nurse Navigator Program Is Effective in Reducing Episode-of-Care Costs Following Primary Hip and Knee Arthroplasty

BackgroundAlternative payment models for total hip arthroplasty (THA) and total knee arthroplasty (TKA) have incentivized providers to deliver higher quality care at a lower cost, prompting some institutions to develop formal nurse navigation programs (NNPs). The purpose of this study was to determine whether a NNP for primary THA and TKA resulted in decreased episode-of-care (EOC) costs.MethodsWe reviewed a consecutive series of primary THA and TKA patients from 2015-2016 using claims data from the Centers for Medicare and Medicaid Services and Medicare Advantage patients from a private insurer. Three nurse navigators were hired to guide discharge disposition and home needs. Ninety-day EOC costs were collected before and after implementation of the NNP. To control for confounding variables, we performed a multivariate regression analysis to determine the independent effect of the NNP on EOC costs.ResultsDuring the study period, 5275 patients underwent primary TKA or THA. When compared with patients in the prenavigator group, the NNP group had reduced 90-day EOC costs ($19,116 vs $20,418 for Medicare and $35,378 vs $36,961 for private payer, P < .001 and P < .012, respectively). Controlling for confounding variables in the multivariate analysis, the NNP resulted in a $1575 per Medicare patient (P < .001) and a $1819 per private payer patient cost reduction (P = .005). This translates to a cost savings of at least $5,556,600 per year.ConclusionThe implementation of a NNP resulted in a marked reduction in EOC costs following primary THA and TKA. The cost savings significantly outweighs the added expense of the program. Providers participating in alternative payment models should consider using a NNP to provide quality arthroplasty care at a reduced cost.     

Is the New Outpatient Prospective Payment System Classification for Outpatient Total Knee Arthroplasty Appropriate?

BackgroundIn 2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the inpatient-only list, resulting in payment through the Outpatient Prospective Payment System with an average $3157 reduction. The purpose of this study is to determine if the reimbursement is justified by comparing the difference in facility costs between inpatient and outpatient TKAs.MethodsWe identified 4496 consecutive primary TKA procedures performed at 2 hospitals from 2015 to 2019. Itemized facility costs were calculated using a time-driven activity-based costing algorithm. Outpatient procedures were defined as those with a length of stay of less than 2 midnights (3851, 86%). Patient demographics, comorbidities, and itemized costs were compared between groups. A multivariate regression analysis was performed to determine the independent effect of outpatient status on true facility costs.ResultsOutpatient TKA patients had lower mean postoperative personnel costs ($1809 vs $947, P < .001), supply costs ($4347 vs $4229, P < .001), and overall total facility costs ($7371 vs $6937, P < .001) than inpatient TKA patients. Controlling for a younger patient cohort with fewer medical comorbidities, outpatient status was associated with a reduction in total facility costs of $972 (95% confidence interval $883-$1060, P < .001) compared to inpatient TKA.ConclusionOutpatient TKA costs hospitals nearly $1000 per patient less than inpatient TKA, yet the average difference in Medicare reimbursement for an outpatient procedure is $3157 less per patient. Centers for Medicare and Medicaid Services should reconsider the Outpatient Prospective Payment System classification of TKA to better incentivize surgeons to perform TKA as a lower cost outpatient procedure when safe and appropriate.     

Can Prior Episode-of-Care Costs Predict the Future? Identifying High-Cost Outliers for Subsequent Total Hip and Knee Arthroplasty

BackgroundIt remains unknown if a patient’s prior episode-of-care (EOC) costs for total hip (THA) or knee (TKA) arthroplasty procedure can be used to predict subsequent costs for future procedures. The purpose of this study is to evaluate whether there is a correlation between the EOC costs for a patient’s index and subsequent THA or TKA.MethodsWe reviewed a consecutive series of 11,599 THA and TKA Medicare patients from 2015 to 2019 and identified all patients who underwent a subsequent THA and TKA during the study period. We collected demographics, comorbidities, short-term outcomes, and 90-day EOC claims costs. A multivariate analysis was performed to identify whether prior high-EOC costs were predictive of high costs for the subsequent procedure.ResultsOf the 774 patients (6.7%) who underwent a subsequent THA or TKA, there was no difference in readmissions (4% vs 5%, P = .70), rate of discharge to a skilled nursing facility (SNF) (15% vs 15%, P = .89), and mean costs ($18,534 vs $18,532, P = .99) between EOCs. High-cost patients for the initial TKA or THA were more likely to be high cost for subsequent procedure (odds ratio 14.33, P < .01). Repeat high-cost patients were more likely to discharge to an SNF for their first and second EOC compared to normative-cost patients (P < .01).ConclusionHigh-cost patients for their initial THA or TKA are likely to be high cost for a subsequent procedure, secondary to a high rate of SNF utilization. Efforts to reduce costs in repeat high-cost patients should focus on addressing post-operative needs pre-operatively to facilitate safe discharge home.     

Staging Total Hip and Knee Arthroplasty Procedures Within 90 Days Increases Costs in Bundled Payment Programs

BackgroundUnder current Medicare bundled payment programs, when a patient undergoes a subsequent elective procedure within the 90-day episode-of-care, the first procedure is excluded from the bundle and a new episode-of-care initiated. The purpose of this study was to determine if staging bilateral total hip (THA) and total knee arthroplasty (TKA) procedures within 90 days have an effect on bundled episode-of-care costs.MethodsWe reviewed a consecutive series of Medicare patients undergoing staged primary THA and TKA from 2015-2019. Patients who underwent a prior procedure within 90 days were compared to those who had undergone a procedure 90-120 days prior. We then performed a multivariate analysis to identify the independent effect of staging timeframe on costs and outcomes.ResultsOf the 136 patients undergoing a staged bilateral THA or TKA, 48 patients underwent staged procedures within 90 days (35%) and 88 patients between 91-120 days (65%). There were no significant differences observed for demographics, comorbidities, complications, readmissions, or discharge disposition (all P > .05). Patients undergoing a staged procedure within 90 days had increased episode-of-care costs by $2021 (95% CI $11-$4032, P = .049), increased postacute care costs by $2019 (95% CI $66-$3971, P < .001), and reduced per-patient margin by $2868 (95% CI-$866-$4869, P = .005).DiscussionPatients undergoing staged bilateral THA or TKA within 90 days have increased episode-of-care costs compared to those undergoing a staged procedure from 91-120 days. Since patients may still not be fully recovered from the first procedure, CMS should address the inappropriate allocation of costs to ensure institutions are not penalized.     

High-Quality Skilled Nursing Facilities Are Associated With Decreased Episode-of-Care Costs Following Total Hip and Knee Arthroplasty

BackgroundWith the increasing popularity of alternative payment models following total hip (THA) and knee arthroplasty (TKA), efforts have focused on reducing post-acute care (PAC) costs, particularly patients discharged to skilled nursing facilities (SNFs). The purpose of this study is to determine if preferentially discharging patients to high-quality SNFs can reduce bundled payment costs for primary THA and TKA.MethodsAt our institution, a quality improvement initiative for SNFs was implemented at the start of 2017, preferentially discharging patients to internally credentialed facilities, designated by several quality measures. Claims data from Centers for Medicare and Medicaid Services were queried to identify patients discharged to SNF following primary total joint arthroplasty. We compared costs and outcomes between patients discharged to credentialed SNF sites and those discharged to other sites.ResultsBetween 2015 and 2018, of a consecutive series of 8778 primary THA and TKA patients, 1284 (14.6%) were discharged to an SNF. Following initiation of the program, 498 patients were discharged to an SNF, 301 (60.4%) of which were sent to a credentialed facility. Patients at credentialed facilities had significantly lower SNF costs ($11,184 vs $8198, P < .0001), PAC costs ($18,952 vs $15,148, P < .0001), and episode-of-care costs ($34,557 vs $30,831, P < .0001), with no difference in readmissions (10% vs 12%, P = .33) or complications (8% vs 6%, P = .15). Controlling for confounding variables, being discharged to a credentialed facility decreased SNF costs by $1961 (P = .0020) and PAC costs by $3126 (P = .0031) per patient.ConclusionQuality improvement efforts through partnership with selective SNFs can significantly decrease PAC costs for patients undergoing primary THA and TKA.     

The Importance of Oral History: Does Dental Implant Placement or Caries One Year Before or After Primary Total Knee Arthroplasty Increase Medical Complications and Periprosthetic Joint Infections?

BackgroundConsensus regarding prior dental problems on the outcomes of total knee arthroplasty (TKA) patients is lacking. Therefore, our objectives were to determine the association of dental caries or dental implant placement in TKA patients on the following: (1) medical complications; (2) health care utilization (lengths of stay and readmissions); (3) implant-related complications; and (4) expenditures.MethodsA retrospective query was performed using an administrative claims database for 3 patient cohorts undergoing primary TKA from 2010 to 2020. Patients who had a history of dental caries or implant placement 1 year prior to TKA (n = 1,466) and 1 year after TKA (n = 1,127) were case-matched to patients who did not have a dental history by age and comorbidities. Outcomes included 90-day complications, health care utilization parameters, 2-year implant complications, and expenditures. Logistic regression models computed odds ratios (OR) of complications and readmissions. P values less than 0.005 were significant.ResultsPatients who had a dental implant placement prior to TKA had higher frequency of complications (20.05 versus 14.01%; OR: 1.53, P < .0001), including myocardial infarctions (2.52 versus 1.23%; OR: 2.08, P = .0002) and pneumonia (2.52 versus 1.24%; OR: 2.06, P = .0002). Lengths of stay (3.28 versus 2.98 days; P = .255), readmission rates (4.71 versus 4.28%; P = .470), and implant-related complications including periprosthetic joint infections (3.14 versus 2.63%; OR: 1.20, P = .279) were similar between patients lacking dental history. Expenditures were higher in patients who had a postoperative and preoperative dental history ($19,252 versus $19,363 versus 17,980; P < .001).ConclusionDental caries or implant placement may reflect overall worse medical condition resulting in more complications and higher costs after TKA. Dental history screening preoperatively may assist arthroplasty surgeons in minimizing complications.     

Robotic-Assisted Versus Manual Unicompartmental Knee Arthroplasty: A Time-Driven Activity-Based Cost Analysis

BackgroundThe cost-effectiveness of robotic-assisted unicompartmental knee arthroplasty (RA-UKA) remains unclear. Time-driven activity-based costing (TDABC) has been shown to accurately reflect true resource utilization. This study aimed to compare true facility costs between RA-UKA and conventional UKA.MethodsWe identified 265 consecutive UKAs (133 RA, 132 conventional) performed at a specialty hospital in 2016-2020. Itemized facility costs were calculated using TDABC. Separate analyses including and excluding implant costs were performed. Multiple regression was performed to determine the independent effect of robotic assistance on facility costs.ResultsDue to longer operative time, RA-UKA patients had higher personnel costs and total facility costs ($2,270 vs $1,854, P < .001). Controlling for demographics and comorbidities, robotic assistance was associated with an increase in personnel costs of $399.25 (95% confidence interval [CI] $343.75-$454.74, P < .001), reduction in supply costs of $55.03 (95% CI $0.56-$109.50, P = .048), and increase in total facility costs of $344.27 (95% CI $265.24-$423.31, P < .001) per case. However, after factoring in implant costs, robotic assistance was associated with a reduction in total facility costs of $235.87 (95% CI $40.88-$430.85, P < .001) per case.ConclusionUsing TDABC, overall facility costs were lower in RA-UKA despite a longer operative time. To facilitate wider adoption of this technology, implant manufacturers may negotiate lower implant costs based on volume commitments when robotic assistance is used. These supply cost savings appear to offset a portion of the increased costs. Nonetheless, further research is needed to determine if RA-UKA can improve clinical outcomes and create value in arthroplasty.     

Preoperative Diagnosis Can Predict Conversion Total Knee Arthroplasty Outcomes

Background

Compared to total knee arthroplasty (TKA) for primary osteoarthritis, conversion TKAs in the post-traumatic setting are associated with increased operative times, infection rates, and readmissions. We aim at determining how post-traumatic osteoarthritis and previous knee surgery influence postoperative outcomes in conversion TKA.

High Bundled Payment Costs Following Total Hip and Knee Arthroplasty in African Americans

BackgroundConcerns exist that minorities who utilize more resources in an episode-of-care following total hip (THA) and knee arthroplasty (TKA) may face difficulties with access to quality arthroplasty care in bundled payment programs. The purpose of this study is to determine if African American patients undergoing TKA or THA have higher episode-of-care costs compared to Caucasian patients.MethodsWe queried Medicare claims data for a consecutive series of 7310 primary TKA and THA patients at our institution from 2015 to 2018. We compared patient demographics, comorbidities, readmissions, and 90-day episode-of-care costs between African American and Caucasian patients. A multivariate regression analysis was performed to identify the independent effect of race on episode-of-care costs.ResultsCompared to Caucasians, African Americans were younger, but had higher rates of pulmonary disease and diabetes. African American patients had increased rates of discharge to a rehabilitation facility (20% vs 13%, P < .001), with higher subacute rehabilitation ($1909 vs $1284, P < .001), home health ($819 vs $698, P = .022), post-acute care ($5656 vs $4961, P = .008), and overall 90-day episode-of-care costs ($19,457 vs $18,694, P = .001). When controlling for confounding comorbidities, African American race was associated with higher episode-of-care costs of $440 (P < .001).ConclusionAfrican American patients have increased episode-of-care costs following THA and TKA when compared to Caucasian patients, mainly due to increased rates of home health and rehabilitation utilization. Further study is needed to identify social variables that can help reduce post-acute care resources and prevent reduction in access to arthroplasty care in bundled payment models.     

Patients With Multiple Sclerosis are at Increased Risk for Postoperative Complications Following Total Hip and Knee Arthroplasty

BackgroundMultiple sclerosis (MS) is a chronic inflammatory demyelinating disease affecting the central nervous system. Patients with MS are living longer due to improved medical therapy and thus the demand for arthroplasty in this population will increase. The objective of this study is to evaluate MS as a potential risk factor for postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA).MethodsPatients with a diagnosis of MS who underwent THA or TKA from 2005 to 2014 were identified in a national insurance database. Rates of death, hospital readmission, emergency room visits, infection, revision, and dislocation (for THA) or stiffness (for TKA) were calculated, in addition to cost and length of stay. MS patients were then compared to a matched control population.ResultsIn total, 3360 patients who underwent THA and 6436 patients who underwent TKA with a history of MS were identified and compared with 10:1 matched control cohorts without MS. The MS group for both TKA and THA had significantly higher incidences of hospital readmission (THA odds ratio [OR] 2.05, P < .001; TKA OR 1.99, P < .001), emergency room visits (THA OR 1.41, P < .001; TKA OR 1.66, P < .001), and infection (THA OR 1.35, P = .001; TKA OR 1.32, P < .001). MS patients who underwent THA had significantly higher rates of revision (OR 1.35, P = .001) and dislocation (OR 1.52, P < .001). Diagnosis of MS was also associated with significantly higher costs and hospital length of stay for patients undergoing both TKA and THA.ConclusionA diagnosis of MS is associated with increased risk of postoperative complications and higher costs following both THA and TKA.     

Reference Pricing Reduces Total Knee Implant Costs

BackgroundReference pricing establishes a set price a hospital is willing to pay for total knee arthroplasty (TKA) components regardless of vendor. The hospital contracts with vendors that sell implants to the hospital at the hospital-dictated prices. Orthopedic surgeons are free to utilize any implant system that has met the reference price using their best clinical judgment. Our hypothesis is that vendors will meet the set price and selection of different vendors and technologies will not change.MethodsWe retrospectively analyzed the 12 months prior (May 2017-2018) and the most recent 12 months after (March 2019-2020) implementing reference pricing at our institution. We investigated differences in average prices for total implant and component costs. We evaluated cost of implants with respect to surgeon volume, assessed the rate of cementless TKAs used, and number of companies purchased from before and after reference pricing.ResultsIn total, 7148 TKAs were included in the study with 3790 arthroplasties before and 3358 after implementation of reference pricing. Overall implant costs decreased by 16.7% (P < .0001). All individual knee component costs decreased by at least 11% (P = .0003). No difference in prices were found among surgeons (P = .9758). Cementless knee use increased by 9% (P < .0001; odds ratio 1.94, 95% confidence interval = 1.69-2.24). No vendor business was lost.ConclusionThe strategy of reference pricing significantly reduced costs for TKA implants at our institution. The reduction in implant costs was regardless of surgeon volume. Newer technologies were utilized more often after reference pricing. This strategy represents a significant cost-savings approach for other hospitals.     

Bundled Payments Are Effective in Reducing Costs Following Bilateral Total Joint Arthroplasty

BackgroundAlternative payment models such the Centers for Medicare and Medicaid Services Bundled Payments for Care Improvement (BPCI) initiative have been effective in reducing costs following unilateral total hip (THA) and knee arthroplasty (TKA), but few studies exist on bilateral arthroplasty. This study aimed to determine whether the BPCI program for bilateral THA and TKA reduced episode-of-care costs.MethodsWe retrospectively reviewed a consecutive series of patients who underwent simultaneous bilateral primary THA and TKA between 2015 and 2016. We recorded demographic variables, comorbidities, readmissions, and calculated 90-day episode-of-care costs based on Centers for Medicare and Medicaid Services claims data. We compared data from patients before and after the start of our BPCI program, and performed a multivariate analysis to identify independent risk factors for increased costs.ResultsOf 319 patients, 38 underwent bilateral THA (12%) while 287 underwent bilateral TKA (88%). There were 239 patients (74%) in the bundled payment group. Although there was no change in readmission rate (9% vs 8%), the post-BPCI group demonstrated reduced hospital costs ($21,251 vs $18,783), post–acute care costs ($15,488 vs $12,439), and overall 90-day episode-of-care costs ($39,733 vs $34,305). When controlling for demographics, procedure, and comorbidities, our BPCI model demonstrated a per-patient reduction of $5811 in overall claims costs. Additional risk factors for increased episode-of-care costs included age ($516/y increase) and cardiac disease ($5916).ConclusionOur bundled payment program for bilateral THA and TKA was successful with reduction in 90-day episode-of-care costs without placing the patient at higher risk of readmission. Older Medicare beneficiaries and those with cardiac disease should likely not undergo a simultaneous bilateral procedure due to concerns about increased costs.     

Is a Titanium Implant for Total Knee Arthroplasty Better? A Randomized Controlled Study

BackgroundLighter weight and lower modulus are potential advantages of titanium (Ti) implants over cobalt chrome (CoCr) implants in total knee arthroplasty (TKA). This study was conducted to determine whether Ti implants in TKA resulted in better clinical outcomes and radiologic results.MethodsOne hundred and eight patients (216 knees) with knee arthritis warranting bilateral primary TKA were randomly allocated to undergo Ti rotating-platform TKA in one knee and CoCr rotating-platform TKA in the contralateral knee. The mean follow-up period was 5.3 years (range, 1-7 years). The weight of Ti implants was one-third lighter than that of CoCr implants (133.9 g vs 390.1 g, P < .01). Clinical outcomes were evaluated using clinical scores, patient preferences (lightness, comfort, naturalness, and satisfaction), gait analysis (kinetic and kinematic data), range of motion, and degree of pain. Radiologic results were evaluated based on the radiolucent line (RLL), degree of medial tibial bone loss, and loosening as seen on X-ray.ResultsNo significant differences were observed in clinical scores or patient preference. Regarding implant weight, approximately 70% of patients did not perceive the Ti implant as lighter. No significant differences were observed in gait analysis, range of motion, or degree of pain. The RLL was seen in 9% of the Ti implant group and 19% of the CoCr implant group.ConclusionThe lighter Ti implant did not show any clinical benefit over CoCr implants. The lightness of the Ti implant is not sufficient to matter or be noticeable. However, the Ti implant showed lower rate of RLL than the CoCr implant.Level of Evidencelevel I, randomized controlled trial.     

Prior Knee Arthroscopy Increases the Failure Rate of Subsequent Unicompartmental Knee Arthroplasty

BackgroundIn selected patients, knee arthroscopy is performed prior to unicompartmental knee arthroplasty (UKA) to treat symptomatic mechanical pathology, delay arthroplasty, and assess the knee compartments. The purpose of this study was to determine if knee arthroscopy prior to UKA is associated with increased rates of UKA failure or conversion to total knee arthroplasty (TKA).MethodsData was collected from the Humana insurance database from 2007-2017. Patients who underwent knee arthroscopy within two years prior to UKA were identified and matched with controls based on age, gender, Charlson Comorbidity Index, smoking status, and obesity. Rates of conversion to TKA and failure for various causes were compared between cohorts.ResultsPrior to propensity matching, 8353 UKA patients met inclusion criteria. Of these, 1079 patients (12.9%) underwent knee arthroscopy within two years of UKA and were matched to 1079 patients (controls) who did not undergo knee arthroscopy in the two years preceding UKA. No differences in demographics/comorbidities existed among cohorts. Compared to controls, the knee arthroscopy cohort was more likely to experience failure for aseptic loosening (2.4% vs 1.1%; OR 2.166; P = .044) and significantly more likely to require conversion to TKA (10.4% vs 4.9%; OR 2.113; P < .001) within two years of UKA.ConclusionKnee arthroscopy within two years of UKA is associated with an increased rate of UKA conversion to TKA and a higher rate of UKA failure from aseptic loosening. Although clinicians should be mindful of this association when performing knee arthroscopy in patients who may be indicated for future UKA, further research is needed to better characterize these findings.     

Concurrent Hardware Removal is Associated With Increased Odds of Infection Following Conversion Total Knee Arthroplasty

BackgroundThe optimal timing of removal of periarticular implants prior to conversion total knee arthroplasty (TKA) remains to be determined. The purpose of this study was to compare infection rates in conversion TKA when hardware removal was performed in either a staged or concurrent manner.MethodsWe performed a retrospective study using a national insurance claims database of patients who underwent removal of hardware on the same day or within 1 year before their TKA. A total of 16,099 patients met the criteria. After matching, both final cohorts consisted of 4,502 patients. The 90-day and 1-year rates of prosthetic joint infection were calculated.ResultsThe rates of infection were 1.64% and 3.00% in the staged group and 2.62% and 3.95% in the concurrent group at 90 days and 1 year postoperatively, respectively (P = .001, P = .01). Logistic regression analyses demonstrated that patients who had hardware removal greater than 3 months prior to TKA had significantly lower odds of infection at 1-year postop (Odds Ratio 0.61 95% Confidence Interval 0.45-0.84; P = .003).ConclusionRemoval of hardware performed concurrently or within 3 months of a TKA is associated with increased odds of prosthetic joint infection at 1 year postoperatively. Surgeons should consider removing periarticular hardware prior to TKA when possible.     

A Novel,Synergistic Model in Total Joint Arthroplasty: A Report of 2 Specialty Hospitals With Joint Ownership Between Physicians and Healthcare Systems

BackgroundIn 2010, the Affordable Care Act introduced new restrictions on the expansion of physician-owned hospitals (POHs) due to concerns over financial incentives and increased costs. The purpose of this study is to determine whether joint ventures between tertiary care and specialty hospitals (SHs) allowing physician ownership (POHs) have improved outcomes and lower cost following THA and TKA.MethodsAfter institutional review board approval, a retrospective review of consecutive series of primary THA and TKA patients from 2015 to 2016 across a single institution comprised of 14 full-service hospitals and 2 SHs owned as a joint venture between physicians and their health system partners. Ninety-day episode-of-care claims cost data from Medicare and a single private insurer were reviewed with the collection of the same demographic data, medical comorbidities, and readmission rates for both the SHs and non-SHs. A multivariate regression analysis was performed to determine the independent effect of the SHs on episode-of-care costs.ResultsOf the 6537 patients in the study, 1936 patients underwent a total joint arthroplasty at an SH (29.6%). Patients undergoing a procedure at an SH had shorter lengths of stay (1.29 days vs 2.23 days for Medicare, 1.15 vs 1.86 for private payer, both P < .001), were less likely to be readmitted (4% vs 7% for Medicare, P = .001), and had lower mean 90-day episode-of-care costs ($16,661 vs $20,579 for Medicare, $26,166 vs $35,222 for private payers, both P < .001). When controlling for the medical comorbidities and demographic variables, undergoing THA or TKA at an SH was associated with a decrease in overall episode costs ($3266 for Medicare, $13,132 for private payer, both P < .001).ConclusionEven after adjusting for a healthier patient population, the joint venture partnership with health systems and physician-owned SHs demonstrated lower 90-day episode-of-care costs than non-SHs following THA and TKA. Policymakers and practices should consider these data when considering the current care pathways.