Comorbidities Have a Greater Impact Than Age Alone in the Outcomes of Octogenarian Total Knee Arthroplasty

Does the impact of peripheral nerve blocks vary by age and comorbidity subgroups? A nationwide population-based study

INTRODUCTION

A large body of literature suggests that peripheral nerve blockade (PNB) is associated with improved perioperative outcomes in total hip and knee joint arthroplasty patients. However, it is unclear to what extent this association exists across patient subgroups based on age and health status.

METHODS

Patients who underwent total joint arthroplasty were identified from the Premier Healthcare database (2006-2019). Mixed-effects models were applied to assess the relationship between exposure of interest (PNB use on the day of surgery) and various outcomes (postoperative respiratory complications, acute renal failure, delirium, intensive care unit admission, prolonged length of stay, and high opioid consumption) across multiple subgroups stratified by patient age and pre-existing comorbidities.

RESULTS

PNB use and outcome association varies based on the patient's health and age characteristics. For adults and older adults with excellent or fair, there was a decrease in the likelihood of respiratory complication with the use of PNB (OR: 0.92, 95% CI 0.86 to 0.98; OR: 0.88, 95% CI 0.81 to 0.95; OR: 0.94, 95% CI 0.89 to 0.99, respectively). Peripheral nerve blocks were also associated with a reduction in the odds of high opioid consumption across all categories except adult patients in poor health.

CONCLUSION

PNB use is associated with beneficial effects more commonly observed among patients with a lower comorbidity burden, without a clear pattern of association with patient age.

Cardiovascular Disease in Total Knee Arthroplasty: An Analysis of Hospital Outcomes, Complications, and Mortality

Background

Cardiovascular comorbidities have been identified as a significant risk factor for adverse outcomes following surgery. The purpose of this study was to investigate its prevalence and impact on postoperative outcomes, hospital metrics, and mortality in patients undergoing total knee arthroplasty (TKA). Our hypothesis was that patients with cardiovascular comorbidities would have worse outcomes, greater postoperative complication rates, and increased mortality compared to patients without cardiovascular disease.

Methods

In this retrospective study, data from the National Inpatient Sample database from 2011 to 2020 were queried for patients who underwent TKA with preexisting cardiac comorbidities, including congestive heart failure (CHF), coronary artery disease (CAD), valvular dysfunction, and arrhythmia. Multivariate logistic regression analyses compared hospital metrics (length of stay, costs, and adverse discharge disposition), postoperative complications, and mortality rates while adjusting for demographic and clinical variables. All statistical analyses were performed using R studio 4.2.2 and Stata MP 17 and 18 with Python package.

Results

A total of 385,585 patients were identified. Those with preexisting CHF, CAD, valvular dysfunction, or arrhythmias were found to be older and at higher risk of adverse outcomes, including prolonged length of stay, increased hospital charges, and increased mortality (p < 0.001). Additionally, all preexisting cardiac diagnoses led to an increased risk of postoperative myocardial infarction, acute kidney injury (AKI), and need for transfusion (p < 0.001). The presence of valvular dysfunction, arrhythmia, or CHF was associated with an increased risk of thromboembolic events (p < 0.001). The presence of CAD and valvular dysfunction was associated with an increased risk of urologic infection (p < 0.001).

Conclusions

This study demonstrated that CHF, CAD, valvular dysfunction, and arrhythmia are prevalent among TKA patients and associated with worse hospital metrics, higher risk of perioperative complications, and increased mortality. As our use of TKA rises, a lower threshold for preoperative cardiology referral in older individuals and early preoperative counseling/intervention in those with known cardiac disease may be necessary to reduce adverse outcomes.

Cemented vs. Cementless Fixation in Primary Knee Replacement: A Narrative Review

Knee osteoarthritis (OA) is one of the leading causes of disability around the globe. Osteoarthritis is mainly considered a disease affecting the elderly. However, more and more studies show that sports overuse, obesity, or congenital disorders can initiate a pathologic cascade that leads to OA changes in the younger population. Nevertheless, OA mostly affects the elderly, and with increasing life expectancy, the disease will develop in more and more individuals. To date, the golden standard in the treatment of the end-stage of the disease is total joint replacement (TJR), which restores painless knee motion and function. One of the weakest elements in TJR is its bonding with the bone, which can be achieved by bonding material, such as poly methyl-methacrylate (PMMA), or by cementless fixation supported by bone ingrowth onto the endoprosthesis surface. Each technique has its advantages; however, the most important factor is the revision rate and survivor time. In the past, numerous articles were published regarding TJR revision rate, but no consensus has been established yet. In this review, we focused on a comparison of cemented and cementless total knee replacement surgeries. We introduced PICO rules, including population, intervention, comparison and outcomes of TJR in a PubMed search. We identified 783 articles published between 2010 and 2023, out of which we included 14 in our review. Our review reveals that there is no universally prescribed approach to fixate knee prostheses. The determination of the most suitable method necessitates an individualized decision-making process involving the active participation and informed consent of each patient.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Patients Who Have Pre-Existing Atrial Fibrillation Require Increased Postoperative Care Following Total Joint Arthroplasty

BACKGROUND

Approximately 9% of total joint arthroplasty (TJA) patients have pre-existing atrial fibrillation (AF). This study examined the effect of pre-existing AF on TJA outcomes.

METHODS

We conducted a 1:3 propensity match of 545 TJA patients who have pre-existing AF to TJA patients who do not have AF at a tertiary care center between January 1st, 2012, and January 1st, 2021. Bivariate and multivariate regressions were performed. Changes over time were evaluated.

RESULTS

Patients undergoing total knee arthroplasty (TKA) who have pre-existing AF, experienced more post-operative AFs (P < .001), acute kidney injuries (P = .026), post-operative complications (POC) (P < .001), and 30-day readmissions (P = .036). Patients undergoing total hip arthroplasty (THA) who have pre-existing AF experienced more post-operative AFs (P < .001), pulmonary embolisms (P < .001), increased estimated blood losses (P = .007), more blood transfusions (P = .002), more POCs (P < .001), and longer lengths of stay (LOS) (P < .002). Over time, POC and LOS decreased in both groups, but remained increased in TJA patients who have pre-existing AF. Multivariate analyses of TKA patients showed an increased odds ratio (OR) of any POCs (P < .001), while THA patients had an increased OR of any POCs (P = .01), and LOS (P = .002).

CONCLUSION

Patients who have pre-existing AF undergoing TJA have more POCs. TKA patients have more readmissions. THA patients have longer LOS. These findings demonstrate the importance of enhanced peri-operative medical management in patients who have pre-existing AF undergoing TJA.

Routine Use of Bladder Scans After Primary Total Joint Arthroplasty is Not Necessary: Results of a Protocol Change

BACKGROUND

Postoperative urinary retention is a common concern after total joint arthroplasty (TJA) and can cause discomfort, incontinence and, if left untreated, myogenic changes to the bladder. However, overdiagnosis of postoperative urinary retention by bladder scans may lead to unnecessary interventions and delayed discharges. The purpose of this study was to compare the safety of two bladder management protocols following TJA.

METHODS

From January 3, 2022 to April 29, 2022, 519 consecutive patients operated on by thirteen surgeons underwent routine postoperative bladder scanning (standard protocol). From February 28, 2022 to April 29, 2022, a new protocol was introduced by three surgeons in 209 consecutive patients using a specific algorithm (selective protocol) so that only symptomatic patients had bladder scans. The primary outcome of interest was catheterization rate. Chi-square and Students t-tests were used for analyses. There were 37.7% of patients in the selective group who received scans.

RESULTS

Times to catheterization, readmissions, emergency department visits, and straight catheterization rates (15.0 versus 14.8% P = .999) were similar. More scans in the selective group resulted in intervention (39.2 versus 15.0%, P < .001). Prevoid volumes were higher in the selective protocol (608 versus 448 mL, P < .001). Postvoid volumes were similar (233 versus 223 mL, P = .497). There was one readmission for a urinary tract infection in the standard group and no urinary-related readmissions in the selective group.

CONCLUSION

The selective protocol had a higher rate of same day discharge, fewer bladder scans, and did not lead to increased rates of urinary-related complications. These findings suggest that selective bladder scanning for symptomatic patients can be safely instituted for TJA patients.

Establishment and evaluation of a predictive model for length of hospital stay after total knee arthroplasty: A single-center retrospective study in China

Background

Total knee arthroplasty (TKA) is the ultimate option for end-stage osteoarthritis, and the demand of this procedure are increasing every year. The length of hospital stay (LOS) greatly affects the overall cost of joint arthroplasty. The purpose of this study was to develop and validate a predictive model using perioperative data to estimate the risk of prolonged LOS in patients undergoing TKA.

Methods

Data for 694 patients after TKA collected retrospectively in our department were analyzed by logistic regression models. Multi-variable logistic regression modeling with forward stepwise elimination was used to determine reduced parameters and establish a prediction model. The discrimination efficacy, calibration efficacy, and clinical utility of the prediction model were evaluated.

Results

Eight independent predictors were identified: non-medical insurance payment, Charlson Comorbidity Index (CCI) ≥ 3, body mass index (BMI) &gt; 25.2, surgery on Monday, age &gt; 67.5, postoperative complications, blood transfusion, and operation time &gt; 120.5 min had a higher probability of hospitalization for ≥6 days. The model had good discrimination [area under the curve (AUC), 0.802 95% CI, 0.754–0.850]] and good calibration (p = 0.929). A decision curve analysis proved that the nomogram was clinically effective.

Conclusion

This study identified risk factors for prolonged hospital stay in patients after TKA. It is important to recognize all the factors that affect hospital LOS to try to maximize the use of medical resources, optimize hospital LOS and ultimately optimize the care of our patients.

Clinical Frailty Scale is a better predictor for adverse post-operative complications and functional outcomes than Modified Frailty Index and Charlson Comorbidity Index after total knee arthroplasty

PURPOSE

Studies have demonstrated correlations between frailty and comorbidity scores with adverse outcomes in total knee replacement (TKR). However, there is a lack of consensus on the most suitable pre-operative assessment tool. This study aims to compare Clinical Frailty Scale (CFS), Modified Frailty Index (MFI), and Charlson Comorbidity Index (CCI) in predicting adverse post-operative complications and functional outcomes following a unilateral TKR.

METHODS

In total, 811 unilateral TKR patients from a tertiary hospital were identified. Pre-operative variables were age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) class, CFS, MFI, and CCI. Binary logistic regression analysis was performed to ascertain odd ratios of pre-operative variables on adverse post-operative complications (length of stay < LOS >, complications, ICU/HD admission, discharge location, 30-day readmission, 2-year reoperation). Multiple linear regression analyses were used to estimate the standardized effects of pre-operative variables on the Knee Society Functional Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), and 36-Item Short Form Survey (SF-36).

RESULTS

CFS is a strong predictor for LOS (OR 1.876, p < 0.001), complications (OR 1.83-4.97, p < 0.05), discharge location (OR 1.84, p < 0.001), and 2-year reoperation rate (OR 1.98, p < .001). ASA and MFI were predictors for ICU/HD admission (OR:4.04, p = 0.002; OR 1.58, p = 0.022, respectively). None of the scores was predictive for 30-day readmission. A higher CFS was associated with a worse outcome for 6-month KSS, 2-year KSS, 6-month OKS, 2-year OKS, and 6-month SF-36.

CONCLUSION

CFS is a superior predictor for post-operative complications and functional outcomes than MFI and CCI in unilateral TKR patients. This suggests the importance of assessing pre-operative functional status when planning for TKR.

LEVEL OF EVIDENCE

Diagnostic, II.

Total knee replacement in octogenarians, Is age a determining factor in predicting complications? a retrospective cohort study

INTRODUCTION

Given the increase in life expectancy in the general population of our country, there is an exponential increase since the last decades of functional older adults who undergo total knee replacement (TKR). There is a direct relationship between the increase in age and the prevalence of both functional and cognitive disabling chronic diseases, however, little we know about whether age is an independent factor in predicting worse functional outcomes and readmissions after TKR. The objective of this study was to evaluate the clinical-functional results and unplanned readmissions within the first 90 postoperative days in patients older than 80 years compared with a control group of patients younger than 80 years.

METHODS

From our institutional patient database, 450 patients who underwent TKR between 2016 and 2019 were retrospectively analyzed. All patients had the medical assurance of Hospital Italiano (Plan de Salud), for which none of these was lost on the follow-up nor were treated in another hospital. Patients were divided in two groups: Group A with 186 patients over 80 years and a control group B with 264 patients between 70 and 80 years. The fragility of these was defined according to the Charlson Comorbidity Index and the Simple Frail Score. Comorbidities were divided in eight groups to define which were the most influential in the final results.

RESULTS

No significant differences were observed in terms of unplanned readmissions, pain or in functional scores within 90 days between both groups. There was a significant difference in the length of postoperative hospital stay in favor of group A (A: 2.56 SD + - 0.76, B: 4.08 SD =  - 2.23; p = 0.00001). The Charlson score was higher in the group of patients older than 80 years (p = 0.02) as well as the Simple Frail Score (p = 0.004). The ASA score did not show significant differences between both groups.

CONCLUSION

Age as an independent factor proved not to be a predictor by itself of unplanned readmissions or worse clinical-functional results in a period of 90 postoperative days between both groups. We believe that the preoperative evaluation of octogenarian patients should be multidisciplinary, with special attention to the identification of comorbidities that can influence the fragility of a patient and the optimization of the pathology.

Incidence, patterns and risk factors for readmission following knee arthroplasty in China: A national retrospective cohort study

BACKGROUND

Limited data exist on readmission following knee arthroplasty (KA) in countries without well-established referral or extended care systems. This study aimed to investigate the incidence, patterns and risk factors for readmission following KA in China.

MATERIAL AND METHODS

In this national retrospective cohort study, we reviewed 167,265 primary KAs registered in the Hospital Quality Monitoring System in China between 2013 and 2018. Readmissions after KA within 30 and 90 days were evaluated. The causes for readmission were identified and classified as surgical or medical. The potential risk factors of readmission were assessed using multivariable logistic regression.

RESULTS

4017 (2.4%) patients readmitted within 30 days, and 7258 (4.3%) patients readmitted within 90 days. The readmission rate exhibited a downward trend during the period from 2013 to 2018 (2.7%-2.3% for 30-day readmission; 4.5%-4.2% for 90-day readmission). Surgical causes contributed to 54.3% readmissions within 30 days and 47.3% readmissions within 90 days. Wound infection/complication, joint pain, and thromboembolism were the most frequently reported reasons for surgical readmission. Older age, male sex, single marital status, non-osteoarthritis indication, a high comorbidity index, non-provincial hospitals, low hospital volume, and longer length of stay were associated with an increased risk of readmission. The geographic regions of hospitals contributed greatly to the variety of readmissions.

CONCLUSION

The readmission rate following KA decreased from 2013 to 2018. Surgery-related causes, especially wound infection/complication and pain, accounted for a large proportion. Both patient and hospital factors were associated with readmissions. Improved primary care and targeted measures are needed to help further prevent readmissions and optimize resource utilization.

The long-term results of total knee arthroplasty in octogenarian

Aims: With increasing life expectancy and ageing population, more octogenarians would benefit from total knee arthroplasty (TKA). The aim of this study is to evaluate the survivorship of TKA in octogenarian and their long-term outcomes. Methods: This was a retrospective review of 67 patients aged above 80 years who had primary TKA performed between 2005 and 2013 at a single centre. A sex-matched younger cohort of 67 primary TKAs during the same time-period was recruited for control. Five and 10-year survival was calculated. Pre- and peri-operative factors were collected and compared. Post-operative range of motion, Knee Society Score (KSS) and Function Score (KFS) were collected and compared. Rate of revision, infection, aseptic loosening and mortality was collected. Results: The mean follow-up period was 10.39 ± 2.29 years. The 5- and 10-year survival of octogenarian group was 85.1% and 54.6%, respectively. Pre- and peri-operative factors between the octogenarian and control groups were comparable (p > 0.05). Both groups showed improvement in range of motion, KSS and KFS post-operatively. Rate of revision, aseptic loosening and deep infection was 0% in octogenarian and 1.5% in control group. Conclusion: TKA can be performed in patients with age above 80 years old with comparable post-op knee range, complication rate and long-term functional score. Advanced age should not be a limiting factor for TKA.

Unicompartmental Knee Arthroplasty in Octogenarians versus Younger Patients: A Comparison of 30-Day Outcomes

As the United States' octogenarian population (persons 80-89 years of age) continues to grow, understanding the risk profile of surgical procedures in elderly patients becomes increasingly important. The purpose of this study was to compare 30-day outcomes following unicompartmental knee arthroplasty (UKA) in octogenarians with those in younger patients. The American College of Surgeons National Surgical Quality Improvement Program database was queried. All patients, aged 60 to 89 years, who underwent UKA from 2005 to 2016 were included. Patients were stratified by age: 60 to 69 (Group 1), 70 to 79 (Group 2), and 80 to 89 years (Group 3). Multivariate regression models were estimated for the outcomes of hospital length of stay (LOS), nonhome discharge, morbidity, reoperation, and readmission within 30 days following UKA. A total of 5,352 patients met inclusion criteria. Group 1 status was associated with a 0.41-day shorter average adjusted LOS (99.5% confidence interval [CI]: 0.67-0.16 days shorter, p < 0.001) relative to Group 3. Group 2 status was not associated with a significantly shorter LOS compared with Group 3. Both Group 1 (odds ratio [OR] = 0.15, 99.5% CI: 0.10-0.23) and Group 2 (OR = 0.33, 99.5% CI: 0.22-0.49) demonstrated significantly lower adjusted odds of nonhome discharge following UKA compared with Group 3. There was no significant difference in adjusted odds of 30-day morbidity, readmission, or reoperation when comparing Group 3 patients with Group 1 or Group 2. While differences in LOS and nonhome discharge were seen, octogenarian status was not associated with increased adjusted odds of 30-day morbidity, readmission, or reoperation. Factors other than age may better predict postoperative complications following UKA.

Red Cell Distribution Width: Commonly Performed Test Predicts Mortality in Primary Total Joint Arthroplasty

INTRODUCTION

Mortality after total joint arthroplasty (TJA) has been thoroughly explored. Short and long-term mortality appear to be correlated with patient comorbidities. Red Cell Distribution Width (RDW) is a commonly performed test that reflects the variation in red blood cell size. This study investigated the utility of RDW, when combined with comorbidity indices, in predicting mortality after TJA.

METHODS

Using a single institutional database, 30,437 primary TJA were identified. Patient demographics (age, gender, body mass index (BMI), pre-operative hemoglobin, RDW, and Charlson Comorbidity Index(CCI)) were queried. The primary outcome was 1-year mortality after TJA. Anemia was defined as hemoglobin <12g/dL for women and <13 g/dL for men. The normal range for RDW is 11.5-14.5%. A preliminary analysis assessed the bivariate association between demographics, preoperative anemia, RDW, CCI, and all-cause mortality within 1-year after TJA. A multivariate regression model was conducted to determine independent predictors of 1-year mortality. Finally, ROC curves were used to compare AUC of RDW, CCI and the combination of both in predicting 1-year mortality.

RESULTS

The mean RDW was 13.6% ± 1.2. Eighteen percent of patients had pre-operative anemia. The mean CCI was 0.4 ± 0.9. RDW, anemia, CCI, and age were significantly associated with a higher incidence of 1-year mortality. RDW, CCI, age, and male sex were found to be independent risk factors for 1-year mortality. RDW (AUC = 0.68) was a better predictor of mortality compared to CCI (AUC = 0.66). The combination of RDW and CCI (AUC = 0.76) predicted 1-year mortality more accurately than CCI or RDW alone.

CONCLUSION

RDW appears to be a useful parameter that, when combined with CCI, can predict the risk for 1-year mortality after TJA.

Octogenarians Undergoing Medial Unicompartmental Knee Arthroplasty Have Similar Patient-Reported Outcomes as Their Younger Counterparts

BACKGROUND

As a procedure with lower surgical morbidity, unicompartmental knee arthroplasty (UKA) may present a practical solution for elderly patients with unicompartmental arthritis. However, few studies have analyzed the results of UKA in the extreme elderly. This study compared the functional and perioperative outcomes between octogenarians and age-appropriate controls undergoing UKA.

METHODS

Prospectively collected data of 44 patients aged ≥80 years who underwent unilateral UKA were analyzed. Each octogenarian was matched 1:3 with 132 patients aged 65-74 years using propensity scores adjusting for gender, body mass index, Charlson comorbidity index, and preoperative scores. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and Short Form-12 were collected preoperatively and 2 years postoperatively. Complications, reoperations, readmissions, and unplanned visits were recorded up to 1 year postoperatively.

RESULTS

The mean age was 70.0 ± 2.7 years in the control group and 83.0 ± 3.0 years in the octogenarian group (P < .001). The percentage of outpatient procedures was comparable (control 50.0%; octogenarian 45.5%; P = .601). With the exception of poorer Short Form-12 physical scores in octogenarians at 2 years (39.4 ± 14.1 vs 44.9 ± 9.2, P = .028), there was no difference in final postoperative scores or improvement in scores between the groups. The rate of complications, reoperations, readmissions, and emergency room visits was also similar. The five-year survivorship was 97% in the control group and 93% in the octogenarian group (P = .148).

CONCLUSION

Octogenarians undergoing UKA can experience clinical outcomes that are similar to those of their younger counterparts. The clinical trajectory outlined may help clinicians provide valuable prognostic information to elderly patients and guide preoperative counseling.

Association between surgical wait time and hospital length of stay in primary total knee and hip arthroplasty

AIMS

In countries with social healthcare systems, such as Canada, patients may experience long wait times and a decline in their health status prior to their operation. The aim of this study is to explore the association between long preoperative wait times (WT) and acute hospital length of stay (LoS) for primary arthroplasty of the knee and hip.

METHODS

The study population was obtained from the provincial Patient Access Registry Nova Scotia (PARNS) and the Canadian national hospital Discharge Access Database (DAD). We included primary total knee and hip arthroplasties (TKA, THA) between 2011 and 2017. Patients waiting longer than the recommended 180 days Canadian national standard were compared to patients waiting equal or less than the standard WT. The primary outcome measure was acute LoS postoperatively. Secondarily, patient demographics, comorbidities, and perioperative parameters were correlated with LoS with multivariate regression.

RESULTS

A total of 11,833 TKAs and 6,627 THAs were included in the study. Mean WT for TKA was 348 days (1 to 3,605) with mean LoS of 3.6 days (1 to 98). Mean WT for THA was 267 days (1 to 2,015) with mean LoS of 4.0 days (1 to 143). There was a significant increase in mean LoS for TKA waiting longer than 180 days (2.5% (SE 1.1); p = 0.028). There was no significant association for THA. Age, sex, surgical year, admittance from home, rural residence, household income, hospital facility, the need for blood transfusion, and comorbidities were all found to influence LoS.

CONCLUSION

Surgical WT longer than 180 days resulted in increased acute LoS for primary TKA. Meeting a shorter WT target may be cost-saving in a social healthcare system by having shorter LoS. Cite this article: Bone Jt Open 2021;2(8):679-684.

Despite Equivalent Medicare Reimbursement, Facility Costs for Outpatient Total Knee Arthroplasty Are Higher Than Unicompartmental Knee Arthroplasty

BACKGROUND

With the recent removal of total knee arthroplasty (TKA) from the Centers for Medicare and Medicaid Services (CMS) Inpatient Only list, facility reimbursement for outpatient TKA now falls under the Outpatient Prospective Payment System at the same rate as unicompartmental knee arthroplasty (UKA). The purpose of this study was to compare true facility costs of patients undergoing outpatient TKA with those undergoing UKA.

METHODS

We reviewed a consecutive series of 2310 outpatient TKA and 231 UKA patients from 2018 to 2019. Outpatient status was defined as a hospital stay of less than 2 midnights. Facility costs were calculated using a time-driven, activity-based costing algorithm. Implants, supplies, medications, and personnel costs were compared between outpatient TKA and UKA patients. A multivariate analysis was performed to control for confounding medical and demographic variables.

RESULTS

When compared with patients undergoing UKA, outpatient TKA patients had higher implant costs ($3403 vs $3081; P < .001) and overall hospital costs ($6350 vs $5594; P < .001). Outpatient TKA patients had a greater length of stay (1.2 vs 0.5 days; P < .001) and greater postoperative personnel costs ($783 vs $166; P < .001) than UKA patients. When controlling for comorbidities, outpatient TKA was associated with a $803 (P < .001) increase in overall facility costs compared with UKA.

CONCLUSION

Despite equivalent reimbursement from CMS as UKA, outpatient TKA has increased facility costs to the hospital. Although implant costs can vary greatly by institution, CMS should consider appropriately reimbursing outpatient TKA for the additional personnel costs when compared with UKA.

Predictive Factors of Extended Length of Hospital Stay Following Total Joint Arthroplasty in a Veterans Affairs Hospital Population

BACKGROUND

Improved perioperative care for total joint arthroplasty (TJA) procedures has resulted in decreased hospital length of stay (LOS), including effective discharge on postoperative day (POD) 1 in many patients. It remains unclear what contributes to discharge delay in patients that are not discharged on POD 1. This study investigated factors associated with delayed discharge in patients whose original planned discharge was on POD 1.

METHODS

A retrospective cohort of 451 patients who underwent a hip or knee TJA procedure from April 2015 to March 2018 with planned discharge on POD 1 was analyzed. Patient characteristics included demographics, lab values, course of treatment, procedure, Charlson Comorbidity Index (CCI), complications, and other factors. Statistical regression was used to identify factors associated with delayed discharge; odds ratios (OR) were calculated for significant factors (α = 0.05).

RESULTS

Of those studied, 70/451 (15.5%) experienced a delay from the planned POD 1 discharge. An increased likelihood of delayed discharge was associated with a nonhome discharge (P < .001, OR = 8.72 [95% CI: 4.22-18.06]) and higher CCI (P = .034, OR = 1.16 [95% CI: 1.01-1.32]). Inpatient physical therapy on the day of surgery was found to significantly correlate with successful discharge on POD 1 (P = .004, OR = 0.44 [95% CI: 0.25-0.77]).

CONCLUSION

Most patients can be discharged on POD 1 after TJA. Physical therapy on the day of surgery increased the likelihood of patients being discharged on POD 1. Those with a higher CCI and a nonhome discharge were more likely to have a discharge delay. This information can help surgeons counsel patients and prepare for postoperative care.

Risk Adjustment for Episode-of-Care Costs After Total Joint Arthroplasty: What is the Additional Cost of Individual Comorbidities and Demographics?

INTRODUCTION

Concerns exist regarding the lack of risk adjustment in alternative payment models for patients who may use more resources in an episode of care. The purpose of this study was to quantify the additional costs associated with individual medical comorbidities and demographic variables.

METHODS

We reviewed a consecutive series of primary total hip and knee arthroplasty patients at our institution from 2015 to 2016 using claims data from Medicare and a single private insurer. We collected demographic data and medical comorbidities for all patients. To control for confounding variables, we performed a stepwise multivariate regression to determine the independent effect of medical comorbidities and demographics on 90-day episode-of-care costs.

RESULTS

Six thousand five hundred thirty-seven consecutive patients were identified (4,835 Medicare and 1,702 private payer patients). The mean 90-day episode-of-care cost for Medicare and private payers was $19,555 and $30,020, respectively. Among Medicare patients, comorbidities that significantly increased episode-of-care costs included heart failure ($3,937, P < 0.001), stroke ($2,604, P = 0.002), renal disease ($2,479, P = 0.004), and diabetes ($1,368, P = 0.002). Demographics that significantly increased costs included age ($221 per year, P < 0.001), body mass index (BMI; $106 per point, P < 0.001), and unmarried marital status ($1896, P < 0.001). Among private payer patients, cardiac disease ($4,765, P = 0.001), BMI ($149 per point, P = 0.004) and age ($119 per year, P = 0.002) were associated with increased costs.

DISCUSSION

Providers participating in alternative payment models should be aware of factors (cardiac history, age, and elevated BMI) associated with increased costs. Further study is needed to determine whether risk adjustment in alternative payment models can prevent problems with access to care for these high-risk patients.

Impact of Postoperative Zolpidem Use on Primary Total Knee Arthroplasty: A Retrospective Matched-Controlled Analysis of a Private Insurance Database

INTRODUCTION

Zolpidem has gained popularity as a pharmaceutical therapy for insomnia, being the most prescribed hypnotic in the United States today. However, it is associated with increased mortality and morbidity. Literature regarding zolpidem use in the total knee arthroplasty (TKA) population is limited. The aim of the study was to analyze postoperative zolpidem use in the TKA population regarding medical and implant complications, falls, and readmission.

METHODS

The study group was queried according to zolpidem use. Controls consisted of patients who underwent primary TKA without a history of hypnotic drug use. Study group patients were matched to controls in a 1:5 ratio by demographics and comorbidities. Results yielded 99,178 study participants and 495,795 controls. Primary endpoints included 90-day medical and implant complications, fall risk, and readmission. Chi-squared test was used to compare categorical variables. Multivariate logistic regression was used to calculate odds (OR) for complications, fall risk, and readmission. A P value less than 0.05 was considered statistically significant.

RESULTS

Study group patients had increased odds of medical complications (OR: 1.76, 95% CI: 1.71-1.82, P < .0001) and implant complications (OR: 1.35, 95% CI: 1.23-1.47, P < .0001) compared to controls. Furthermore, patients in the study group were found to have an increased risk of 90- day falls (OR: 1.16, 95% CI: 1.11-1.21, P < .0001). Readmission was similar to controls (5.10% vs 4.84%, P = .12).

CONCLUSION

Zolpidem use following primary TKA is associated with the risk of morbidity and falls. The findings are consistent with the literature regarding zolpidem. These findings may affect discussion between orthopedic surgeons and patients in the decision-making process prior to undergoing TKA.

[Decision for total hip arthroplasty-the surgeons' view]

BACKGROUND

The decision for total hip arthroplasty (THA) is based on pain, loss of function, radiological changes and failed conservative therapy. These criteria are rarely based on systematic research and have not been integrated in generally accepted treatment guidelines. Aim of our study was, therefore, to analyse which decision criteria German orthopaedic and trauma surgeons use in order to recommend THA for patients with hip osteoarthritis.

MATERIALS AND METHODS

From 10/2019 to 07/2020 we conducted a nation-wide survey among 218 orthopaedic and trauma surgeons about their criteria for and against THA surgery, as well as their treatment objectives.

RESULTS

147 fully completed questionnaires were analysed. Pain (99%), limitation of movement (99%), as well as impairment of walking distance (97%), and the subjective burden (97%) were the most frequent criteria. 97% and 96% of surgeons consider prescription of analgesics and physical therapy, as well as a lack of their effectiveness, as criteria for THA. 87% see radiological changes grade Kellgren & Lawrence III as threshold. A recommendation against surgery is triggered by obesity (BMI ≥ 40 kg/m²) in 48% and by the presence of an active infection in 96%.

CONCLUSIONS

Current surgeons' practice criteria of recommendations for THA in Germany seem to reflect widely nationally and internationally discussed recommendations. Particular attention is given to patient factors like pain, loss of function and subjective burden, as well as previous conservative treatment and contraindications, like poorly controlled diabetes or an active infection, whereas morbid obesity is not seen as contraindication by all surgeons.

Patient-Related Risk Factors for Unplanned 30-Day Hospital Readmission Following Primary and Revision Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Total knee arthroplasty (TKA) is a highly effective procedure for advanced osteoarthritis of the knee. Thirty-day hospital readmission is an adverse outcome related to complications, which can be mitigated by identifying associated risk factors. We aimed to identify patient-related characteristics associated with unplanned 30-day readmission following TKA, and to determine the effect size of the association between these risk factors and unplanned 30-day readmission. We searched MEDLINE and EMBASE from inception to 8 September 2020 for English language articles. Reference lists of included articles were searched for additional literature. Patients of interest were TKA recipients (primary and revision) compared for 30-day readmission to any institution, due to any cause, based on patient risk factors; case series were excluded. Two reviewers independently extracted data and carried out critical appraisal. In-hospital complications during the index admission were the strongest risk factors for 30-day readmission in both primary and revision TKA patients, suggesting discharge planning to include closer post-discharge monitoring to prevent avoidable readmission may be warranted. Further research could determine whether closer monitoring post-discharge would prevent unplanned but avoidable readmissions. Increased comorbidity burden correlated with increased risk, as did specific comorbidities. Body mass index was not strongly correlated with readmission risk. Demographic risk factors included low socioeconomic status, but the impact of age on readmission risk was less clear. These risk factors can also be included in predictive models for 30-day readmission in TKA patients to identify high-risk patients as part of risk reduction programs.

Associations between comorbidity and quality of life outcomes after total joint replacement

PURPOSE

We examined associations between self-reported and clinician-assessed comorbidity and quality of life (QOL) outcomes after hip and knee replacement.

METHODS

This is a cross-sectional, questionnaire-based national survey. Participants aged 45 years or older (n = 409) were recruited from the New Zealand Joint Registry six months after a total hip (THR), total knee (TKR) or unicompartmental knee replacement (UKR). The main outcome QOL was measured using an 8-item short form of the World Health Organisation Quality of Life (WHOQOL-Bref) questionnaire six months following joint replacement surgery. The WHOQOL is a generic and non-health condition specific measure of QOL.

RESULTS

Participants were on average 68 years of age, with more men (54%) than women (46%). Number of coexisting conditions and body mass index were correlated with age, pain and function scores, and QOL (p < 0.01), but not with each other. Linear regression analyses showed that comorbidities such as number of comorbid conditions and BMI had moderate associations with QOL outcomes.

CONCLUSION

This study showed that general QOL outcomes following hip and knee joint replacement, while generally high, were associated with comorbidity burden and BMI. Future prospective research examining change in QOL before and following surgery would help to advance understandings of the various factors that contribute to patient satisfaction with their joint replacement.

What Are Risk Factors for Infection after Primary or Revision Total Joint Arthroplasty in Patients Older Than 80 Years?

BACKGROUND

Patients older than 80 years of age form an increasing proportion of the patient population undergoing total joint arthroplasty (TJA). With increasing life expectancy and the success of TJA, orthopaedic surgeons are more likely to operate on patients older than 80 years than ever before. Given that most other studies focus on younger populations, only evaluate primary TJA, or limit patient populations to institutional or regional data, we felt a large-database, nationwide analysis of this demographic cohort was warranted, and we wished to consider both primary and revision TJA.

QUESTIONS/PURPOSES

In this study, we sought to investigate the risk factors for surgical site infections (SSIs) at 90 days and periprosthetic joint infections (PJIs) at 2 years after surgery in patients aged 80 years and older undergoing (1) primary and (2) revision lower extremity TJA.

METHODS

All patients aged 80 years or older who underwent primary or revision TJA between 2005 and 2014 were identified using the Medicare Analytical Files of the PearlDiver Supercomputer using ICD-9 codes. This database is unique in that it is one of the largest nationwide databases, and so it provides a large enough sample size of patients 80 years or older. Additionally, this database provides comprehensive and longitudinal patient data tracking, and a low error rate. Our final cohort consisted of 503,241 patients (TKA: n = 275,717; THA: n = 162,489; revision TKA: n = 28,779; revision THA: n = 36,256). Multivariate logistic regression models were constructed to evaluate the association of risk factors on the incidences of 90-day SSI and 2-year PJI. Variables such as sex, diabetes, BMI, and congestive heart failure, were included in the multivariate regression models. Several high-risk comorbidities as identified by the Charlson and Elixhauser comorbidity indices were selected to construct the models. We performed a Bonferroni-adjusted correction to account for the fact that multiple statistical comparisons were made, with a p value < 0.002 being considered statistically significant.

RESULTS

For primary TKA patients, an increased risk of 90-day SSIs was associated with male sex (OR 1.28 [95% CI 1.25 to 1.52]; p < 0.001), BMI greater than 25 k/m (p < 0.001), and other comorbidities. For primary THA patients, an increased risk of 90-day SSIs was associated with patients with obesity (BMI 30-39 kg/m; OR 1.91 [95% CI 1.60 to 2.26]; p < 0.001) and those with morbid obesity (BMI 40-70 kg/m; OR 2.58 [95% CI 1.95 to 3.36]; p < 0.001). For revision TKA patients, an increased risk of SSI was associated with iron-deficiency anemia (OR 1.82 [95% CI 1.37 to 2.28]; p < 0.001). For revision THA patients, electrolyte imbalance (OR 1.48 [95% CI 1.23 to 1.79]; p < 0.001) and iron-deficiency anemia (OR 1.63 [95% CI 1.35 to 1.99]; p < 0.001) were associated with an increased risk of 90-day SSI. Similar associations were noted for PJI in each cohort.

CONCLUSIONS

These findings show that in this population, male sex, obesity, hypertension, iron-deficiency anemia, among other high-risk comorbidities are associated with a higher risk of SSIs and PJIs. Based on these findings, orthopaedic surgeons should actively engage in comanagement strategies with internists and other specialists to address modifiable risk factors through practices such as weight management programs, blood pressure reduction, and electrolyte balancing. Furthermore, this data should encourage healthcare systems and policy makers to recognize that this patient demographic is at increased risks for PJI or SSI, and these risks must be considered when negotiating payment bundles.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Demographics, Treatment, and Cost of Periprosthetic Femur Fractures: Fixation Versus Revision

Introduction:

Periprosthetic femur fractures (PPFX) are complications of both total hip and knee arthroplasty and may be treated with open reduction and internal fixation (ORIF) or revision arthroplasty. Differences in treatment and fracture location may be related to patient demographics and lead to differences in cost. Our study examined the effects of demographics and treatment of knee and hip PPFXs on length of stay (LOS) and cost.

Methods:

Of all, 932 patients were identified with hip or knee PPFXs in the National Inpatient Sample from January 2013 to September 2015. Age, gender, race, mortality, comorbidity level, LOS, total cost, procedure type, geographic region, and hospital type were recorded. A generalized linear regression model was conducted to analyze the effect of fracture type on LOS and cost.

Results:

Differences in gender (66% vs 83.7% female, P < .01), comorbidities (fewer in hips, P < .01), and costs (US$30 979 vs US$27 944, P < .01) were found between the hip and knee groups. Knees had significantly higher rates of ORIF treatment (80.7% vs 39.1%) and lower rates of revision arthroplasties (19.3% vs 60.9%) than hip PPFXs (P < .01). Within both groups, patients with more comorbidities, revision surgery, and blood transfusions were more likely to have a longer LOS and higher cost.

Conclusion:

Periprosthetic femur fractures patients are not homogenous and treatment varies between hip and knee locations. For knee patients, those treated with ORIF were younger, with fewer comorbidities than those treated with revision. Conversely, hip patients treated with ORIF were older, with more comorbidities than those treated with revision. Hips had higher costs than knees, and cost correlated with revision arthroplasty and more comorbidities. In both hip and knee groups, longer LOS was associated with more comorbidities and being treated in urban teaching hospitals. Total cost had the strongest associations with revision procedures as well as number of comorbidities and blood product use.

HIGHER RISK OF COMPLICATIONS AFTER TOTAL KNEE ARTHROPLASTY IN OCTOGENARIANS

Objective:

To evaluate the complication rate of total knee arthroplasty (TKA) in octogenarian patients and identify predictive factors.

Methods:

The study comprised 70 octogenarians and 70 non-octogenarian patients as control group, all submitted to TKA. We analyzed the medical records of these patients, seeking for complications during the first postoperative year. Regarding the risk factors, we evaluated: age, sex, race, American Society of Anesthesiologists score, body mass index, smoking, hypertension and diabetes mellitus.

Results:

In the control group, the incidence of complications was 7.1%. Whereas in the octogenarian group it was significantly higher, reaching 34.3% (OR 6.8; 95% CI 2.4-19.1). We found no association to sex, skin color, and comorbidities. Age is an independent risk factor for postoperative complications. Our data may help patients to acknowledge the risks of undergoing primary TKA and physicians to assess and adjust perioperative risk.

Conclusion:

The incidence of postoperative complications is significantly higher in octogenarians. Level of Evidence III, Case-control study.

Physical Therapist Management of Total Knee Arthroplasty

A clinical practice guideline on total knee arthroplasty was developed by an American Physical Therapy (APTA) volunteer guideline development group that consisted of physical therapists, an orthopedic surgeon, a nurse, and a consumer. The guideline was based on systematic reviews of current scientific and clinical information and accepted approaches to management of total knee arthroplasty.

Are We Treating Similar Patients? Hospital Volume and the Difference in Patient Populations for Total Knee Arthroplasty

BACKGROUND

Early findings of superior total knee arthroplasty (TKA) outcomes at high volume centers have been thought to have led to distinct referral patterns. However, the effect of these selective referral processes has not been well assessed. Therefore, this study compared the characteristics of primary TKA patients at high, intermediate, and low volume hospitals.

METHODS

A total of 12,541 primary TKA patients were stratified into risk groups based on age (>65 years), body mass index (>40), and Charlson Comorbidity Index (≥4). Hospitals were classified as low, intermediate, or high volume based on mean annual TKA volumes (<250, 250-499, and >500). Multivariate logistic regression models evaluated the relationship between baseline patient characteristics and hospital volume.

RESULTS

There was a greater percentage of high risk patients at high volume (19%, n = 853) compared to those at intermediate (16%, n = 899) or low volume (17%, n = 444) hospitals (P < .001). Patients with a body mass index >40 were more likely to be treated at high compared to intermediate (odds ratio [OR] 1.4, 95% confidence interval [CI] 1.2-1.6, P < .001) and low volume centers (OR 1.4, 95% CI 1.2-1.7, P < .001). Patients with Charlson Comorbidity Index scores ≥4 were also more likely be treated at high compared to intermediate (OR 1.5, 95% CI 1.3-1.6, P < .001) or low (OR 1.2, 95% CI 1.0-1.4, P = .002) volume centers.

CONCLUSION

This study found that TKA patients at high volume centers have significantly different baseline characteristics compared to those at lower volume centers. This study highlights the importance of considering hospital volume status and the associated disparity in the preoperative risk of patients when comparing primary TKA outcomes between centers.

Preoperative Risk Factor Optimization Lowers Hospital Length of Stay and Postoperative Emergency Department Visits in Primary Total Hip and Knee Arthroplasty Patients

BACKGROUND

The evaluation and management of outcomes risk has become an essential element of a modern total joint replacement program. Our multidisciplinary team designed an evidence-based tool to address modifiable risk factors for adverse outcomes after primary hip and knee arthroplasty surgery.

METHODS

Our protocols were designed to identify, intervene, and mitigate risk through evidence-based patient optimization. Nurse navigators screened patients preoperatively, identified and treated risk factors, and followed patients for 90 days postoperatively. We compared patients participating in our optimization program (N = 104) to both a historical cohort (N = 193) and a contemporary cohort (N = 166).

RESULTS

Risk factor identification and optimization resulted in lower hospital length of stay (LOS) and postoperative emergency department (ED) visits. Patients in the optimization cohort had a statistically significant decrease in mean LOS as compared to both the historical cohort (2.55 vs 1.81 days, P < .001) and contemporary cohort (2.56 vs 1.81 days, P < .001). Patients in the optimization cohort had a statistically significant decrease in 30- and 90-day ED visits compared to the historical cohort (P_30-day = .042, P_90-day = .003). When compared with the contemporary cohort, the optimization cohort had a statistically significant decrease in 90-day ED visits (21.08% vs 10.58%, P = .025). The optimization cohort had a statistically significant increase in the percentage of patients discharged home. We noted nonsignificant reductions in readmission rate, transfusion rate, and surgical site infections.

CONCLUSION

Optimization of patients before elective primary total hip arthroplasty and total knee arthroplasty reduced average LOS, ED visits, and drove telerehabilitation use. Our results add to the limited body of literature supporting this patient-centered approach.

Hospital Volume and Postoperative Infections in Total Knee Arthroplasty

BACKGROUND

The purpose of this study was to evaluate the associations of hospital volume with revision surgery for infection and superficial incisional infections.

METHODS

A review of 12,541 primary total knee arthroplasties (TKAs) at a large integrated health system from 2014 to 2017 was conducted. Sixteen hospitals were classified as low-volume, medium-volume, or high-volume hospitals according to the mean number of TKAs/year (<250, 250-500, and >500, respectively). Thresholds were guided by percentiles and the literature on volume-outcome relationships. Medical records were reviewed for revision surgery for infection and superficial incisional infections during a mean 2-year review period. Multivariate analyses, adjusted for clinical and patient characteristics, were performed to evaluate the association between hospital volume and infection.

RESULTS

The overall rate of revision surgery for infection was 0.7% (n = 82), and the overall rate of superficial incisional infection was 2.6% (n = 324). After accounting for potential confounders, hospital volume was not found to have a significant association with revision surgery for infection when comparing high-volume and low-volume hospitals (odds ratio, 1.615; 95% confidence interval, 0.761-3.427; P = .212) as well as when comparing high-volume and medium-volume hospitals (odds ratio, 1.464; 95% confidence interval, 0.853-2.512; P = .166). Moreover, the risk of superficial incisional infection at high-volume hospitals was similar to that at low-volume (P = .107) and medium-volume (P = .491) hospitals.

CONCLUSION

Infection outcomes are quality metrics that are frequently used to compare hospitals including those of varying volumes. Using contemporary thresholds, this study found that infection rates after TKA at high-volume hospitals are comparable to low-volume and medium-volume hospitals.

Preoperative Patient Factors Affecting Length of Stay following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Total knee arthroplasty (TKA) yields substantial improvements in quality of life for patients with severe osteoarthritis. Previous research has shown that TKA outcomes are inferior in patients with certain demographic and clinical factors. Length of stay (LOS) following TKA is a major component of costs incurred by healthcare providers. It is hypothesized that patient-related factors may influence LOS following TKA. The purpose of this systematic review and meta-analysis is to investigate these factors.

METHODS

Three databases (PubMed, Embase, and OVID Medline) were searched using variants of the terms "total knee arthroplasty" and "length of stay". Studies were screened and data abstracted in duplicate. The primary outcome was the effect of prognostic variables on LOS following TKA. Meta-analysis was performed using the Review Manager (RevMan) software (version 5.3. Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2014).

RESULTS

A total of 68 studies met all inclusion criteria for this review. These studies comprised 21,494,459 patients undergoing TKA with mean age 66.82 years (range, 15-95 years) and 63.8% (12,165,160 of 19,060,572 reported) females. The mean MINORS score was 7, suggesting that studies had a low quality of evidence. Mean LOS following TKA has steadily decreased over the past 4 decades, partially because of the implementation of fast-track programs. Demographic factors associated with increased LOS were age >70 years (mean difference [MD] = 0.81; 95% confidence interval [CI] = 0.38-1.24), female gender (MD = 0.32; 95% CI = 0.29-0.48), body mass index >30 (MD = 0.09; 95% CI = 0.01-0.16), and non-White race (MD = 0.20; 95% CI = 0.10-0.29). Clinical factors associated with increased LOS were American Society of Anesthesiologists score 3-4 vs 1-2 (MD = 1.12; 95% CI = 0.58 to 1.66), Charlson Comorbidity Index > 0 vs 0 (MD = 0.77; 95% CI = 0.32 to 1.22), and preoperative hemoglobin < 130 g/L (MD = 0.66; 95% CI = 0.34 to 0.98).

CONCLUSION

This systematic review and meta-analysis showed that increased age, female gender, body mass index ≥ 30, non-White race, American Society of Anesthesiologists > 2, Charlson Comorbidity Index > 0, and preoperative hemoglobin < 130 g/L were predictors of increased LOS. Mean LOS has steadily decreased over the past decades with the implementation of perioperative "fast-track" programs. Future research should investigate the benefits of preoperative risk factor modification on LOS, in addition to novel surgical approaches, anesthetic adjuvants, and physiotherapy modifications.

LEVEL OF EVIDENCE

IV, systematic review, and meta-analysis of level III and IV evidence.

Effect of Antibiotic-Impregnated Bone Cement in Primary Total Knee Arthroplasty

BACKGROUND

The purpose of this study is to evaluate the effect of commercially available antibiotic-impregnated bone cement (AIBC) on (1) prosthetic joint infections (PJIs) and (2) surgical site infections (SSIs) after primary total knee arthroplasty (TKA).

METHODS

A review of primary TKAs between 2014 and 2017 from an institutional database was conducted. This identified 12,541 cases which were separated into AIBC (n = 4337) and non-AIBC (8,164) cohorts. Medical records were reviewed for PJIs and SSIs (mean 2-year postoperative period). Infection rates between the cohorts were compared with univariate analyses followed by subanalysis of high risk patients (defined as having 2 or more of the following characteristics: >65 years, body mass index >40, or Charlson Comorbidity Index score >3). To control for confounders, multivariate analyses were performed with regression models adjusted for age, gender, body mass index, comorbidities, year, operative times, and lengths of stay.

RESULTS

On univariate analysis, PJI rates were higher in the AIBC cohort (1.0%) compared to the non-AIBC cohort (0.5%, P < .001). Subanalysis of the high risk patients also showed that PJI rates were higher in the AIBC cohort (1.9% vs 0.6%, P < .01). After adjusting for potential confounders, no significant associations between PJIs and AIBC use were found (odds ratio 1.4, 95% confidence interval 0.9-2.3, P = .133). Similarly, no significant differences in SSI rates were observed between the AIBC (2.9%) and non-AIBC cohorts (2.4%, P = .060) and no significant associations between SSIs and AIBC were found with multivariate analysis (odds ratio 1.0, 95% confidence interval CI 0.8-1.3, P = .948).

CONCLUSION

This study found that there was no clinically or statistically significant decrease in infection rates with AIBC in primary TKAs.

Prevalence and treatment of hip and knee osteoarthritis in people aged 60 years or older in Germany: an analysis based on health insurance claims data

Objective

Osteoarthritis (OA) is highly prevalent throughout the world, especially in the elderly population, and is strongly associated with patients’ frailty. However, little is known about the prevalence and treatment of OA in elderly patients in routine clinical care in Germany.

Materials and methods

As a part of Linking Patient-Reported Outcomes with CLAIms Data for Health Services Research in Rheumatology (PROCLAIR), a cross-sectional study using claims data from a large Germany statutory health insurance (BARMER) was conducted. We included people aged 60 years or older and assessed the prevalence of OA of the hip or knee, defined as having outpatient diagnoses (ICD: M16 or M17) in at least two quarters of 2014. The use of conservative treatment, including analgesics and physical therapy, and total joint replacement was studied. Analyses were stratified by age, sex, comorbidities, and level of care dependency defined by social law.

Results

A total of 595,754 patients (mean age: 74.9 years; 69.8% female) were diagnosed with OA (21.8%), with the highest prevalence in those between 80 and 89 years (31.0%) and in females compared to males (23.9% vs 18.3%). Prevalence decreased with increasing level of care dependency from 30.5% in patients with a low level (0/1) to 18.7% in the highest level of care dependency. A total of 63.4% of the patients with OA received analgesics, with higher use with increasing age. Physical therapy was prescribed to 43.1% of the patients, but use decreased with age. In all, 5.3% of the patients received total joint replacement in 2014.

Conclusion

The lower frequency of coded OA with increasing level of care dependency may reflect underdiagnosis, and patients with many other medical problems seem to be at risk for inadequate recognition and treatment of their OA.

Patient Outcomes After Total Knee Arthroplasty in Patients Older Than 80 Years

BACKGROUND

Patients aged 80 and above who suffer from end-stage osteoarthritis may benefit from total knee arthroplasty (TKA), but at high potential risk. Additionally, there is controversy about whether functional improvement in patients above age 80 is similar to younger patients. We compared functional improvement, length of stay (LOS), and facility discharge rates after TKA between this cohort and patients less than 80 years of age.

METHODS

We completed a retrospective cohort study comparing TKA patients aged 80 and above with all patients younger than 80. We utilized data from a prospectively collected institutional repository of 2308 TKAs performed from April 2011 through July 2016 at an academic medical center in the United States. We performed multivariable logistic regression to determine the association between age group and clinically significant improvement in the Patient-Reported Outcome Measurement Information System (PROMIS)-10 physical component summary (PCS) score. Secondary outcomes included the magnitude of PCS change, LOS, and facility discharge.

RESULTS

There were 175 (7.6%) TKAs in patients older than 80 years compared with 2133 TKAs in patients younger than 80. Patients over 80 had similar adjusted odds of achieving clinically significant PCS improvement following TKA (P = .366), and there was no statistical difference in adjusted postoperative PCS improvement between the 2 age groups. Age 80 and above was associated with a longer adjusted LOS and demonstrated increased odds of facility discharge (odds ratio 4.11, P < .001) after TKA.

CONCLUSION

Following TKA, patients older than 80 years demonstrate similar adjusted functional improvement in comparison to younger patients. However, older patients did require substantially more resources as they remained in the hospital longer and were discharged to rehabilitation more often.

Acceptable Functional Outcomes and Patient Satisfaction Following Total Knee Arthroplasty in Asians with Severe Knee Stiffness: A Matched Analysis

Background

This study evaluated outcomes following total knee arthroplasty for severely stiff knees in Asians.

Methods

Registry data of patients undergoing primary total knee arthroplasty between 2004 and 2013 were collected and retrospectively reviewed. Sociodemographic and anthropometric data together with the Oxford Knee Score and the Knee Society Score (Knee Society Knee Score and the Knee Society Function Score) were collected both preoperatively and postoperatively for up to 2 years. Case subjects consisted of patients with a preoperative flexion range of ≤ 20°. Control subjects consisted of patients with a preoperative flexion range of > 90°. Patients were matched for age, sex, and all preoperative scores in a 2:1 fashion. Two-year outcomes and 5-year revision rates were then compared between cases and controls.

Results

There were 28 cases and 56 controls. Cases had a significantly lower body mass index than the controls (p = 0.003) and had a longer hospital stay (p < 0.0001). At 2 years, cases had a significantly lower flexion range (p < 0.001) and a lower Knee Society Function Score (p = 0.020) than the controls. Cases had a significantly greater improvement in the flexion range (p < 0.001) postoperatively than controls. The mean change in functional outcomes at 2 years was comparable between the two groups. Seventy-one percent of the cases and 88% of controls were satisfied. There was a significant difference in the 5-year revision rate (10% vs 0%, p = 0.013). More cases were discharged to a rehabilitation facility compared to controls (p = 0.011). There were no differences in inpatient complication rates.

Conclusions

Functional outcomes and patient satisfaction were acceptable following total knee arthroplasty in Asian patients with severe knee stiffness.

Risk Adjustment Is Necessary in Medicare Bundled Payment Models for Total Hip and Knee Arthroplasty

BACKGROUND

Concerns exist that high-risk patients in alternative payment models may face difficulties with access to care without proper risk adjustment. The purpose of this study is to identify the effect of medical and orthopedic specific risk factors on the cost of a 90-day episode of care following total hip (THA) and knee arthroplasty (TKA).

METHODS

We queried the Medicare 5% Limited Data Set for all patients undergoing primary THA and TKA from 2010 to 2014. To evaluate the cost of an episode of care, we calculated all claims for 90 days following surgery. Multivariate analysis was performed to quantify the added episode-of-care costs for demographic variables, geography, medical comorbidities, and orthopedic specific risk factors.

RESULTS

Of the 58,809 TKA patients, the median 90-day Medicare costs was $23,800 (interquartile range, $18,900-$32,300), while the median of the 27,293 THA patients was $24,000 (interquartile range, $18,500-$33,900). Independent risk factors (all P < .05) resulting in at least a 10% increase in episode-of-care costs following TKA included malnutrition, age over 85, male gender, pulmonary disorder, failed internal fixation, Northeast region, lower socioeconomic status, neurologic disorder, and rheumatoid arthritis. Independent risk factors (all P < .05) resulting in at least a 10% increase in episode-of-care costs following THA included malnutrition, male gender, age over 85, failed internal fixation, hip dysplasia, Northeast region, neurologic disorder, lower socioeconomic status, conversion THA, avascular necrosis, and depression.

CONCLUSION

Certain comorbidities and orthopedic risk factors increase 90-day episode-of-care costs in the Medicare population. The current lack of proper risk stratification could be a powerful driver of decreased access to care for our most medically challenged members of society.

Should Medicare Remove Total Knee Arthroplasty From Its Inpatient Only List? A Total Knee Arthroplasty Is Not a Partial Knee Arthroplasty

BACKGROUND

The Centers for Medicare and Medicaid Services have solicited comments to consider removing total knee arthroplasty (TKA) from the Inpatient Only list, as it has done for unicompartmental knee arthroplasty (UKA). The purpose of this study is to determine whether Medicare-aged patients undergoing TKA had comparable outcomes to those undergoing UKA.

METHODS

We queried the American College of Surgeons-National Surgical Quality Improvement Program database for all patients aged 65 years or older who underwent elective TKA or UKA from 2014 and 2015. Demographic variables, comorbidities, length of stay (LOS), 30-day complication, and readmission rates were compared between UKA and TKA patients. A multivariate regression analysis was then performed to identify independent risk factors for complications and hospital LOS greater than 1 day.

RESULTS

Of the 50,487 patients in the study, there were 49,136 (97%) TKA patients and 1351 UKA patients (3%). Medicare-aged TKA patients had a longer mean LOS (2.97 vs 1.57 days, P < .001), had a higher complication rate (9% vs 3%, P < .001), and were more likely to be discharged to a rehabilitation facility (31% vs 9%, P < .001) than Medicare-aged UKA patients. When controlling for other variables, TKA patients were more likely to experience a complication (odds ratio, 2.562; P < .001) and require LOS >1 day (odds ratio, 14.679; P < .001) than UKA patients.

CONCLUSION

TKA procedure in the Medicare population is an independent risk factor for increased complications and LOS compared to UKA. Policymakers should use caution extrapolating UKA data to TKA patients and recognize the inherent disparities between the 2 procedures.