Total joint replacement outcomes in patients with concomitant comorbidities: a glass half empty or half full?

Telerehabilitation following fast-track total knee arthroplasty is effective and safe: a randomized controlled trial with the ReHub® platform

PURPOSE

After a total knee arthroplasty (TKA), ensuring rehabilitation is continued at home is essential for a successful recovery. The aim of this randomized clinical trial (NCT04155957) was to demonstrate the safety and efficacy of an interactive telerehabilitation system (ReHub®) to guide and provide feedback during exercise in the postoperative period of a fast-track TKA program.

METHODS

Fifty-two patients who underwent TKA were randomized to intervention (N = 26) or control (N = 26). Upon discharge, they followed a 4-week plan of 5 daily exercises and up to 10 physiotherapy home visits. The intervention group performed exercises with ReHub® autonomously, control did not use any auxiliary device. Data were collected 1) on the day of discharge, 2) after 2 weeks and 3) after 4 weeks.

RESULTS

Telerehabilitation patients showed higher adherence to exercise (p = 0.002) and greater quadriceps strength (p = 0.028). No significant differences between groups were found in other outcomes. Only 1 adverse event was linked to ReHub®. Patients gave the platform high System Usability Scale scores (83/100).

CONCLUSION

Interactive telerehabilitation with ReHub® during a post-TKA exercise program is effective, safe, and well-received by patients. It provides real-time performance feedback and ensures communication. Quadriceps strength and adherence to the exercise plan are improved with ReHub®.

Recovery Curve for Patient Reported Outcomes and Objective Physical Activity After Primary Total Knee Arthroplasty - A Multicenter Study Using Wearable Technology

BACKGROUND

This study aimed to describe the trajectory of recovery based on patient reported outcomes (PROs) and objective metrics of physical activity measures over the first 12 months post-total knee arthroplasty (TKA).

METHODS

In total, 1,005 participants who underwent a primary unilateral TKA surgery between November 2018 and September 2021 from a multi-site prospective study were analyzed. Generalized estimating equations were used to evaluate PROs and objective physical activity measures over time.

RESULTS

All Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), EuroQol-5D (EQ-5D) and steps per day scores were greater than pre-operative scores (P<0.05). The flights of stairs per day, gait speed and walking asymmetry all declined at 1-month (all, P<0.001). However, all subsequent scores improved by 6 months (all, P<0.01). The greatest clinically important differences from previous visit in KOOS JR (β=18.1; 95% Confidence Interval (CI)=17.2, 19.0), EQ-5D (β=0.11; 95% CI=0.10, 0.12), steps per day (β=1169.3; 95% CI=1012.7, 1325.9), gait speed (β=-0.05; 95% CI=-0.06, -0.03), and walking asymmetry (β=0.00; 95% CI=-0.03, 0.03) were observed at 3 months.

CONCLUSION

The KOOS JR, EQ-5D, and steps per day measures showed earlier improvements than other physical activity metrics, with the greatest magnitude of improvement within the first 3 months post-TKA. The greatest magnitude of improvement in walking asymmetry was not observed until 6 months, while gait speed and flights of stairs per day were not observed until 12 months. This data may further help provide expectation setting information to patients prior to surgery, and may aid in identifying outliers to the normal recovery curve who may benefit from targeted interventions.

Patient-rated satisfaction and improvement following hip and knee replacements: Development of prediction models

RATIONALE

Effective preoperative assessments of determinants of health status and function may improve postoperative outcomes.

AIMS AND OBJECTIVES

We developed risk scores of preoperative patient factors and patient-reported outcome measures (PROMs) as predictors of patient-rated satisfaction and improvement following hip and knee replacements.

PATIENTS AND METHODS

Prospectively collected National Health Service and independent sector patient data (n = 30,457), including patients' self-reported demographics, comorbidities, PROMs (Oxford Hip/Knee score (OHS/OKS) and European Quality of Life (EQ5D index and health-scale), were analysed. Outcomes were defined as patient-reported satisfaction and improvement following surgery at 7-month follow-up. Univariable and multivariable-adjusted logistic regressions were undertaken to build prediction models; model discrimination was evaluated with the concordance index (c-index) and nomograms were developed to allow the estimation of probabilities.

RESULTS

Of the 14,651 subjects with responses for satisfaction following hip replacements 564 (3.8%) reported dissatisfaction, and 1433 (9.2%) of the 15,560 following knee replacement reported dissatisfaction. A total of 14,662 had responses for perceived improvement following hip replacement (lack of improvement in 391; 2.7%) and 15,588 following knee replacement (lack of improvements in 1092; 7.0%). Patients reporting poor outcomes had worse preoperative PROMs. Several factors, including age, gender, patient comorbidities and EQ5D, were included in the final prediction models: C-indices of these models were 0.613 and 0.618 for dissatisfaction and lack of improvement, respectively, for hip replacement and 0.614 and 0.598, respectively, for knee replacement.

CONCLUSIONS

Using easily accessible preoperative patient factors, including PROMs, we developed models which may help predict dissatisfaction and lack of improvement following hip and knee replacements and facilitate risk stratification and decision-making processes.

The Paradox of Patient-Reported Outcome Measures: Should We Prioritize "Feeling Better" or "Feeling Good" After Total Knee Arthroplasty?

BACKGROUND

The use of preoperative patient-reported outcome measure (PROM) thresholds for patient selection in arthroplasty care has been questioned recently. This study aimed to identify factors affecting achievement of the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) after total knee arthroplasty (TKA) and determine the overlap between the two outcomes.

METHODS

We identified 1,239 primary, unilateral TKAs performed at a single institution in 2015-2019. PROMs including the Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and 12-item Short Form Health Survey (SF-12) were collected preoperatively and 1-year postoperatively. The likelihood of attaining PASS as per attainment of MCID was assessed. A multivariable regression was used to identify predictors of MCID and PASS.

RESULTS

In total, 71.3% achieved MCID and 75.5% achieved PASS for KOOS-JR. Only 7.7% achieved MCID but not PASS, whereas almost twice this number did not achieve MCID but did achieve PASS (11.9%). Poorer preoperative KOOS-JR (OR 0.925), better SF-12 physical (OR 1.025), and mental (OR 1.027) were associated with MCID attainment. In contrast, better preoperative KOOS-JR (OR 1.030) and SF-12 mental (OR 1.025) were associated with PASS attainment. Age, gender, race, ethnicity, body mass index, Charlson index, American Society of Anesthesiologists classification, and smoking status were not significant predictors.

CONCLUSION

Preoperative PROMs were associated with achieving MCID and PASS after TKA, albeit some positively and some negatively. In the era of value-based care, clinicians should not only strive to help patients "feel better" but also ensure that patients "feel good" after surgery. This study does not support the use of PROMs in prioritizing access to care.

The Effect of Patient Age and Surgical Appropriateness and Their Influence on Surgeon Recommendations for Primary TKA: A Cross-Sectional Study of 2,037 Patients

BACKGROUND

Rising total knee arthroplasty (TKA) rates in younger patients raises concern about appropriateness. We asked: are younger individuals who seek consultation for TKA less likely to be appropriate for and, controlling for appropriateness, more likely to be recommended for surgery?

METHODS

This cross-sectional study was nested within a prospective cohort study of knee osteoarthritis (OA) patients referred for TKA from 2014 to 2016 to centralized arthroplasty centers in Alberta, Canada. Pre-consultation, questionnaires assessed patients' TKA appropriateness (need, based on knee symptoms and prior treatment; readiness/willingness to undergo TKA; health status; and expectations) and contextual factors (for example, employment). Post-consultation, surgeons confirmed study eligibility and reported their TKA recommendation. Using generalized estimating equations to control for clustering by surgeon, we assessed relationships between patient age (<50, 50 to 59, ≥60 years) and TKA appropriateness and receipt of a surgeon TKA recommendation.

RESULTS

Of 2,037 participants, 3.3% and 22.7% were <50 and 50 to 59 years of age, respectively, 58.7% were female, and 35.5% were employed. Compared with older participants, younger participants reported significantly worse knee symptoms, higher use of OA therapies, higher TKA readiness, and similar willingness, but had higher body mass index and were more likely to smoke and to consider the ability to participate in vigorous activities, for example, sports, as very important TKA outcomes. TKA was offered to 1,500 individuals (73.6% overall; 52.2%, 71.0%, and 75.4% of those <50, 50 to 59, and ≥60 years, respectively). In multivariate analyses, the odds of receiving a TKA recommendation were higher with greater TKA need and willingness, in nonsmokers, and in those who indicated that improved ability to go upstairs and to straighten the leg were very important TKA outcomes. Controlling for TKA appropriateness, patient age was not associated with surgeons' TKA recommendations.

CONCLUSIONS

Younger individuals with knee OA referred for TKA had similar or greater TKA need, readiness, and willingness than older individuals. Incorporation of TKA appropriateness criteria into TKA decision-making may facilitate consideration of TKA benefits and risks in a growing population of young, obese individuals with knee OA.

CLINICAL RELEVANCE

Younger people seeking TKA for knee OA had significant OA pain and disability despite recommended OA therapies, suggesting appropriateness for surgical consideration. However, they were significantly more likely to have morbid obesity, to smoke, and to consider return to vigorous activities, like sport, as important TKA outcomes. Whether the short- and longer-term risks of TKA are outweighed by the benefits is unclear and warrants additional research.

Comorbidities do not limit improvement in pain and physical function after total knee arthroplasty in patients with knee osteoarthritis: the BEST-Knee prospective cohort study

OBJECTIVE

To assess the relationship between comorbidities and amount of improvement in pain and physical function in recipients of total knee arthroplasty (TKA) for knee osteoarthritis (OA).

DESIGN

Prospective cohort study.

SETTING

Two provincial central intake hip and knee centres in Alberta, Canada.

PARTICIPANTS

1051 participants (278 in 6-minute walk test (6MWT) subset), ≥30 years of age with primary knee OA referred for consultation regarding elective primary TKA; assessed 1 month prior and 12 months after TKA.

PRIMARY AND SECONDARY OUTCOME MEASURES

Pre-post TKA change in knee OA pain (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)), physical function (Knee injury and Osteoarthritis Outcome Score (KOOS) Physical Function Short-Form) and 6MWT walking distance; and the reporting of an acceptable symptom state (Patient Acceptable Symptom State (PASS)) at 12 months after TKA.

RESULTS

Mean participant age was 67 years (SD 8.8), 59% were female and 85% reported at least one comorbidity. Individuals with a higher number of comorbidities had worse pre-TKA and post-TKA scores for pain, physical function and 6MWT distance. At 12-month follow-up, mean changes in pain, function and 6MWT distance, and proportion reporting a PASS, were similar for those with and without comorbidities. In multivariable regression analysis, adjusted for potential confounders and clustering by surgeon, no specific comorbidities nor total number of comorbidities were associated with less improvement in pain, physical function or 6MWT distance at 12 months after TKA. Patients with diabetes (OR 0.64, 95% CI 0.44 to 0.94) and a higher number of lower extremity troublesome joints (OR 0.85, 95% CI 0.76 to 0.96) had lower odds of reporting a PASS.

CONCLUSION

For individuals with knee OA, comorbid conditions do not limit improvement in pain, physical function or walking ability after TKA, and most conditions do not impact achieving an acceptable symptom state.

Curcumin and Freshwater Clam Extracts Alleviate the Progression of Osteoarthritis by Reducing Synovial Inflammation and Allowing Cartilage Regeneration

Osteoarthritis (OA) is a common degenerative disorder and is accompanied by numerous pain symptoms. With increased age, individuals develop a chronic inflammatory status, and pro-inflammatory cytokines as well as mediators contribute to the progression of OA. However, no desirable remedies have been completely able to inhibit OA progression or safely provide effective symptomatic relief. Natural component extracts or dietary-derived compounds are widely used for anti-inflammatory diseases. Curcumin and freshwater clam extract (FCE) have been proven as functional foods that are able to regulate immune systems. This study demonstrated that curcumin and FCE had synergistic effects on alleviating the progression of OA by assuaging inflammation and repairing the cartilage within the joints. After consumption of curcumin and FCE, the severity of synovitis was quantified by the infrapatellar fat pad inflammation scoring system and the Osteoarthritis Research Society International (OARSI) scoring system. Significant improvement and articular cartilage regeneration were noted. Moreover, once the inflammation within the joints was reduced, the animals redistributed their body weight on the OA-induced hindlimb. In summary, curcumin and FCE possess desirable anti-inflammatory and repair functions, suggesting their potential as alternative remedies in the management of OA or other inflammatory diseases.

FDA public workshop: Orthopaedic sensing, measuring, and advanced reporting technology (SMART) devices

Traditional orthopaedic devices do not communicate with physicians or patients post-operatively. After implantation, follow-up of traditional orthopaedic devices is generally limited to episodic monitoring. However, the orthopaedic community may be shifting towards incorporation of smart technology. Smart technology in orthopaedics is a term that encompasses a wide range of potential applications. Smart orthopaedic implants offer the possibility of gathering data and exchanging it with an external reader. They incorporate technology that enables automated sensing, measuring, processing, and reporting of patient or device parameters at or near the implant. While including advanced technology in orthopaedic devices has the potential to benefit patients, physicians, and the scientific community, it may also increase the patient risks associated with the implants. Understanding the benefit-risk profile of new smart orthopaedic devices is critical to ensuring their safety and effectiveness. The 2018 FDA public workshop on orthopaedic sensing, measuring, and advanced reporting technology (SMART) devices was held on April 30, 2018, at the FDA White Oak Campus in Silver Spring, MD with the goal of fostering a collaborative dialogue amongst the orthopaedic community. Workshop attendees discussed four key areas related to smart orthopaedic devices: engineering and technology considerations, clinical and patient perspectives, cybersecurity, and regulatory considerations. The workshop presentations and associated discussions highlighted the need for the orthopaedic community to collectively craft a responsible path for incorporating smart technology in musculoskeletal disease care.

A Portable System for Remote Rehabilitation Following a Total Knee Replacement: A Pilot Randomized Controlled Clinical Study

Rehabilitation has been shown to improve functional outcomes following total knee replacement (TKR). However, its delivery and associated costs are highly variable. The authors have developed and previously validated the accuracy of a remote (wearable) rehabilitation monitoring platform (interACTION). The present study’s objective was to assess the feasibility of utilizing interACTION for the remote management of rehabilitation after TKR and to determine a preliminary estimate of the effects of the interACTION system on the value of rehabilitation. Specifically, we tested post-operative outpatient rehabilitation supplemented with interACTION (n = 13) by comparing it to a standard post-operative outpatient rehabilitation program (n = 12) using a randomized design. Attrition rates were relatively low and not significantly different between groups, indicating that participants found both interventions acceptable. A small (not statistically significant) decrease in the number of physical therapy visits was observed in the interACTION Group, therefore no significant difference in total cost could be observed. All patients and physical therapists in the interACTION Group indicated that they would use the system again in the future. Therefore, the next steps are to address the concerns identified in this pilot study and to expand the platform to include behavioral change strategies prior to conducting a full-scale randomized controlled trial. Trial registration: ClinicalTrials.gov NCT02646761 “interACTION: A Portable Joint Function Monitoring and Training System for Remote Rehabilitation Following TKA” 6 January 2016.

Knee Osteoarthritis Treatment Costs in the Medicare Patient Population

BACKGROUND

Several nonoperative options have been recommended for the treatment of knee osteoarthritis (OA), with varying degrees of evidence. Adhering to the American Academy of Orthopaedic Surgeons clinical practice guidelines has been suggested to decrease direct treatment costs by 45% in the year before knee arthroplasty, but this does not consider the cost of the entire episode of care, including the cost of surgery and postsurgery care.

OBJECTIVES

To analyze the total treatment costs after a diagnosis of knee OA, as well as the proportion of arthroplasty interventions as part of the total knee OA-related costs, and whether the total costs differed for patients who received intra-articular hyaluronic acid and/or had knee arthroplasty.

METHODS

We identified patients newly diagnosed with knee OA using the 5% Medicare data sample from January 2010 to December 2015. Patients were excluded if they were aged <65 years, had incomplete claim history, did not reside in any of the 50 states, had claim history <12 months before knee OA diagnosis, or did not enroll in Medicare Part A and Part B. The study analyzed knee OA-related costs from a payer perspective in terms of reimbursements provided by Medicare, as well as the time from the diagnosis of knee OA to knee arthroplasty for patients who had knee arthroplasty, and the time from the first hyaluronic acid injection to knee arthroplasty for those who received the injection. We compared patients who received hyaluronic acid and those who did not receive hyaluronic acid injections. Patients who received hyaluronic acid injection who subsequently had knee arthroplasty were also compared with those who did not have subsequent knee arthroplasty.

RESULTS

Of the 275,256 patients with knee OA, 45,801 (16.6%) received a hyaluronic acid injection and 35,465 (12.9%) had knee arthroplasty during the study period. The median time to knee arthroplasty was 16.4 months for patients who received hyaluronic acid versus 5.7 months for those who did not receive hyaluronic acid. Non-arthroplasty-related therapies and knee arthroplasty accounted for similar proportions of knee OA-related costs, with hyaluronic acid injection comprising 5.6% of the total knee OA-related costs. For patients who received hyaluronic acid injections and subsequently had knee arthroplasty, hyaluronic acid injection contributed 1.8% of the knee OA-related costs versus 76.6% of the cost from knee arthroplasty. Patients who received hyaluronic acid injections and did not have knee arthroplasty incurred less than 10% of the knee OA-related costs that patients who had surgery incurred.

CONCLUSION

Although limiting hyaluronic acid use may reduce the knee OA-related costs, in this study hyaluronic acid injection only comprised a small fraction of the overall costs related to knee OA. Among patients who had knee arthroplasty, those who received treatment with hyaluronic acid had surgery delayed by a median of 10.7 months and associated costs for a significant period. The ability to delay or avoid knee arthroplasty altogether can have a substantial impact on healthcare costs.

Knee OA cost comparison for hyaluronic acid and knee arthroplasty

BACKGROUND

Limiting treatment to those recommended by the American Academy of Orthopaedic Surgeon Clinical Practice Guidelines has been suggested to decrease costs by 45% in the year prior to total knee arthroplasty, but this only focuses on expenditures leading up to, but not including, the surgery and not the entire episode of care. We evaluated the treatment costs following knee osteoarthritis (OA) diagnosis and determined whether these are different for patients who use intra-articular hyaluronic acid (HA) and/or knee arthroplasty.

METHODS

Claims data from a large commercial database containing de-identified data of more than 100 million patients with continuous coverage from 2012 to 2016 was used to evaluate the cumulative cost of care for over 2 million de-identified members with knee OA over a 4.5-year period between 2011 and 2015. Median cumulative costs were then stratified for patients with or without HA and/or knee arthroplasty.

RESULTS

Knee OA treatment costs for 1,567,024 patients over the 4.5-year period was $6.60 billion (mean $4210/patient) as calculated by the authors. HA and knee arthroplasty accounted for 3.0 and 61.5% of the overall costs, respectively. For patients who underwent knee arthroplasty, a spike in median costs occurred sooner for patients without HA use (around the 5- to 6-month time point) compared to patients treated with HA (around the 16- to 17-month time point).

CONCLUSIONS

Non-arthroplasty therapies, as calculated by the authors, accounted for about one third of the costs in treating knee OA in our cohort. Although some have theorized that limiting the use of HA may reduce the costs of OA treatment, HA only comprised a small fraction (3%) of the overall costs. Among patients who underwent knee arthroplasty, those treated with HA experienced elevated costs from the surgery later than those without HA, which reflects their longer time to undergoing knee arthroplasty. The ability to delay or avoid knee arthroplasty altogether can have a substantial impact on the cost to the healthcare system.

Individual Gait Features Are Associated with Clinical Improvement After Total Knee Arthroplasty

Background:

Over 20% of patients do not report clinically relevant pain relief or functional improvements after total knee arthroplasty (TKA). The aim of this study was to investigate the effect of demographics, pre-TKA knee-joint biomechanics, and postoperative changes in knee biomechanics on meaningful improvements in self-reported pain and function after TKA.

Methods:

Forty-six patients underwent 3-dimensional gait analysis and completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire before and 1 year after TKA. Response to treatment in terms of pain relief and functional improvement (“pain and function responders”) was defined as improvements in WOMAC scores that met minimal clinically important difference thresholds in the pain and function domains. Differences between responder and non-responder demographics, severity of the osteoarthritis as seen radiographically, and knee kinematics and kinetics before TKA were explored using the t test and Mann-Whitney U test. Correlations and regression models were used to examine demographics, baseline knee kinematics and kinetics, and post-TKA kinematic and kinetic improvements associated with being a pain responder and a function responder separately. Analyses were conducted using a hypothesis-driving approach.

Results:

Of the 46 patients, 34 were pain responders and 36 were function responders. Preoperatively, both responder groups had a higher radiographic severity (Kellgren-Lawrence) grade (p = 0.03) and pain responders were more symptomatic according to their WOMAC score (p < 0.04). Less preoperative stance-phase flexion-extension angle range (p ≤ 0.03), lower preoperative stance-phase adduction (varus) angle magnitude (p = 0.01), and less postoperative reduction in the adduction angle magnitude (p ≤ 0.009) were independently associated with more self-reported improvement in pain and function.

Conclusions:

Patients with a higher radiographic severity grade, with specific frontal and sagittal knee kinematic patterns during gait before TKA, and who demonstrated less reduction in frontal plane angles during gait after TKA had greater self-reported pain and function score improvements after standard TKA. Gait analysis may aid preoperative identification of kinematic subgroups associated with self-reported improvements after TKA, and provide evidence that may inform triaging, surgical planning, and expectation management strategies.

Level of Evidence:

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

Does Patient Experience After a Total Knee Arthroplasty Predict Readmission?

BACKGROUND

To our knowledge, the relationship between patient Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores and patient outcomes in total knee arthroplasty (TKA) has not yet been analyzed. Therefore, the purpose of this study is to determine whether readmissions within the 30 or 90 days postoperative window after TKA were predicted by patient satisfaction scores, as measured by the HCAHPS survey.

METHODS

We analyzed HCAHPS survey scores from all patients who underwent primary or revision TKA at our institution between January 1, 2016 and September 1, 2016. Demographic readmission information, preoperative baseline health status measures, validated patient-reported pain and joint function measures, and HCAHPS survey scores were collected. To determine whether 30-day or 90-day readmissions were independently associated with HCAHPS scores, statistical analyses were conducted using chi-squared and Student's t-tests for categorical and continuous variables. Multivariable regression analysis adjusted for patient-level risk factors.

RESULTS

Patients readmitted within 30 days were significantly less likely to choose the highest rating on survey questions in several dimensions of patient satisfaction when compared to patients who were not readmitted. These dimensions included physician communication (P = .045), discharge information (P = .016), and transition of care (P = .044). Similarly, patients who were readmitted within 90 days were less likely to choose the highest rating in survey questions that pertained to physician communication (P = .046), medication information (P = .040), and quietness of the hospital environment (P = .048).

CONCLUSION

Our results show that readmission is predicted by lower patient satisfaction scores in several dimensions of patient care including physician communication, hospital environment, medication information, discharge information, and transition of care.

The Recovery Curve for the Patient-Reported Outcomes Measurement Information System Patient-Reported Physical Function and Pain Interference Computerized Adaptive Tests After Primary Total Knee Arthroplasty

BACKGROUND

We sought to characterize the typical recovery in physical function (PF) and pain interference (PI) after TKA using Patient-Reported Outcomes Measurement Information System (PROMIS) patient-reported outcome (PRO) measures.

METHODS

Ninety-one patients were enrolled into an institutional review board -approved prospective observational study. PROs were obtained preoperatively and postoperatively at 6 weeks, 3 months, 6 months, and 1 year. PROs included the PROMIS PF computerized adaptive test (CAT) and the PROMIS PI CAT. Generalized estimating equations were used to evaluate outcomes over time.

RESULTS

There was no difference in the preoperative and 6-week postoperative T-scores for the PF CAT (P = .410). However, all subsequent postoperative T-scores were greater than the preoperative T-score (all, P < 0.05). There was a significant reduction in PI CAT T-scores between the preoperative and all subsequent postoperative T-scores (all, P < .05). A clinically important difference in PF CAT T-scores (β = 5.44, 95% confidence interval 4.10-6.80; P < .001) and PI CAT T-scores (β = -7.46, 95% confidence interval -9.52 to -5.40; P < 0.001) was seen between the preoperative and 3-month postoperative visits. Sixty-three percent of the improvement in PF occurred by 3 months, and 89% had occurred by 6 months. The majority of reduction in PI (68%) occurred by 3 months and 90% had occurred by 6 months.

CONCLUSION

The greatest magnitude of improvement in both PF and PI occurred within the first 3 months. After 6 months, patients might expect modest improvements in PF and mild reductions of PI. Patients and surgeons should use this information for setting expectations, planning for recovery, and improving care.

Early Clinically Relevant Improvement in Quality of Life and Clinical Outcomes 1 Year Postsurgery in Patients with Knee and Hip Joint Arthroplasties

Objective To measure and identify the determinants of the outcomes after hip/knee arthroplasty (HA/KA) in patients with osteoarthritis during the first postsurgical year. Design In this prospective observational study, we evaluated the preoperative and postoperative (3, 6, and 12 months) outcomes of 626 patients who underwent HA (346 with median age 65 years, 59% female) or KA (280 with median age 66.5 years, 54% female) between 2008 and 2013. Generic and specific tools were used to measure health-related quality of life (HRQoL) and utility. Good outcome was defined as an improvement in WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) greater than or equal to the minimal important difference (MID). Regressions were performed to evaluate the relationship between preoperative and postoperative measures and evolution of WOMAC/good outcome. Results We observed an almost systematic improvement of all parameters for up to 12 months, but especially at the 3-month follow-up. The low number of comorbidities and the absence of postoperative complications were the common determinants of improvement of WOMAC total score after 12 months. Other parameters (background of the joint, preoperative function and length of hospital stay in KA group; place of discharge in HA group) affected the evolution of WOMAC scores. 87.09% of HA and 73.06% of KA patients experienced a good outcome. A small number of comorbidities, a worse preoperative function, a shortened hospital stay (KA only), and an absence of early postoperative complications (HA only) significantly predicted a good outcome. Conclusions Intermediate HRQoL following HA or KA improved quickly from preoperative levels for all instruments. More than 70% of patients achieved a good outcome defined as improved pain, stiffness and disability and the predictors are slightly close.

Current Risk Adjustment and Comorbidity Index Underperformance in Predicting Post-Acute Utilization and Hospital Readmissions After Joint Replacements: Implications for Comprehensive Care for Joint Replacement Model

OBJECTIVE

To compare the performances of 3 comorbidity indices, the Charlson Comorbidity Index, the Elixhauser Comorbidity Index, and the Centers for Medicare & Medicaid Services (CMS) risk adjustment model, Hierarchical Condition Category (HCC), in predicting post-acute discharge settings and hospital readmission for patients after joint replacement.

METHODS

A retrospective study of Medicare beneficiaries with total knee replacement (TKR) or total hip replacement (THR) discharged from hospitals in 2009-2011 (n = 607,349) was performed. Study outcomes were post-acute discharge setting and unplanned 30-, 60-, and 90-day hospital readmissions. Logistic regression models were built to compare the performance of the 3 comorbidity indices using C statistics. The base model included patient demographics and hospital use. Subsequent models included 1 of the 3 comorbidity indices. Additional multivariable logistic regression models were built to identify individual comorbid conditions associated with high risk of hospital readmissions.

RESULTS

The 30-, 60-, and 90-day unplanned hospital readmission rates were 5.3%, 7.2%, and 8.5%, respectively. Patients were most frequently discharged to home health (46.3%), followed by skilled nursing facility (40.9%) and inpatient rehabilitation facility (12.7%). The C statistics for the base model in predicting post-acute discharge setting and 30-, 60-, and 90-day readmission in TKR and THR were between 0.63 and 0.67. Adding the Charlson Comorbidity Index, the Elixhauser Comorbidity Index, or HCC increased the C statistic minimally from the base model for predicting both discharge settings and hospital readmission. The health conditions most frequently associated with hospital readmission were diabetes mellitus, pulmonary disease, arrhythmias, and heart disease.

CONCLUSION

The comorbidity indices and CMS-HCC demonstrated weak discriminatory ability to predict post-acute discharge settings and hospital readmission following joint replacement.

Trajectories of Pain and Function after Primary Hip and Knee Arthroplasty: The ADAPT Cohort Study

Background and Purpose

Pain and function improve dramatically in the first three months after hip and knee arthroplasty but the trajectory after three months is less well described. It is also unclear how pre-operative pain and function influence short- and long-term recovery. We explored the trajectory of change in function and pain until and beyond 3-months post-operatively and the influence of pre-operative self-reported symptoms.

Methods

The study was a prospective cohort study of 164 patients undergoing primary hip (n = 80) or knee (n = 84) arthroplasty in the United Kingdom. Self-reported measures of pain and function using the Western Ontario and McMaster Universities Osteoarthritis index were collected pre-operatively and at 3 and 12 months post-operatively. Hip and knee arthroplasties were analysed separately, and patients were split into two groups: those with high or low symptoms pre-operatively. Multilevel regression models were used for each outcome (pain and function), and the trajectories of change were charted (0–3 months and 3–12 months).

Results

Hip: Most improvement occurred within the first 3 months following hip surgery and patients with worse pre-operative scores had greater changes. The mean changes observed between 3 and twelve months were statistically insignificant. One year after surgery, patients with worse pre-operative scores had post-operative outcomes similar to those observed among patients with less severe pre-operative symptoms. Knee: Most improvement occurred in the first 3 months following knee surgery with no significant change thereafter. Despite greater mean change during the first three months, patients with worse pre-operative scores had not ‘caught-up’ with those with less severe pre-operative symptoms 12 months after their surgery.

Conclusion

Most symptomatic improvement occurred within the first 3 months after surgery with no significant change between 3–12 months. Further investigations are now required to determine if patients with severe symptoms at the time of their knee arthroplasty have a different pre-surgical history than those with less severe symptoms and if they could benefit from earlier surgical intervention and tailored rehabilitation to achieve better post-operative patient-reported outcomes.

Improvement following total knee replacement surgery: Exploring preoperative symptoms and change in preoperative symptoms

OBJECTIVE

To determine whether changes in preoperative osteoarthritis (OA) symptoms are associated with improvement after total knee replacement (TKR) and to identify predictors of clinically significant improvement.

METHODS

Data on Osteoarthritis Initiative participants who were annually assessed and underwent TKR were included. T0 was the assessment prior to TKR while T-1 was the assessment prior to that. T+2 was the second assessment after TKR. We compiled data on the Western Ontario and McMaster Universities OA Index (WOMAC), OA-related symptoms, and radiographic severity. We defined clinically significant improvement as improvement in WOMAC total score ≥ to the minimal important difference (MID) (0.5 SD of mean change) between T0 and T+2 and also considered other definitions of improvement. Logistic regression models were performed to evaluate the relationship between improvement and preoperative measures.

RESULTS

Improved (n = 211) compared to unimproved (n = 58) patients had greater worsening of their WOMAC pain (p = 0.002) and disability (p < 0.001) from T-1 to T0. Preoperative measures as predictors of improvement included higher WOMAC disability (OR = 1.08, p < 0.001), presence of chronic OA symptoms in the surgical knee (OR = 5.77, p = 0.033), absence of OA-related symptoms in the contralateral knee (OR = 9.25, p < 0.001), exposure to frequent knee bending (OR = 3.46, p = 0.040), and having a Kellgren-Lawrence x-ray grade of ≥2 in the contralateral knee (OR = 4.71, p = 0.010).

CONCLUSIONS

More than 75% of participants had improvement after TKR. Improved patients were more likely to have escalation of OA pain and disability prior to surgery than unimproved patients. Other preoperative measures predicted improvement after TKR.