Predictors of moderate-severe functional limitation after primary Total Knee Arthroplasty (TKA): 4701 TKAs at 2-years and 2935 TKAs at 5-years

Development of a clinical prediction rule for mobility status at discharge in patients with total knee arthroplasty: Using a decision tree model

BACKGROUND

Total knee arthroplasty (TKA) is an effective treatment to improve mobility in patients with severe knee osteoarthritis. However, some patients continue to have poor mobility after surgery. The preoperative identification of patients with poor mobility after TKA allows for better treatment selection and appropriate goal setting. The purpose of this study was to develop a clinical prediction rule (CPR) to predict mobility after TKA.

METHODS

This study included patients undergoing primary TKA. Predictors of outcome included patient characteristics, physical function, and psychological factors, which were measured preoperatively. The outcome measure was the Timed Up and Go test, which was measured at discharge. Patients with a score of ≥11 s were considered having a low-level of mobility. The classification and regression tree methodology of decision tree analysis was used for developing a CPR.

RESULTS

Of the 101 cases (mean age, 72.2 years; 71.3 % female), 26 (25.7 %) were classified as low-mobility. Predictors were the modified Gait Efficacy Scale, age, knee pain on the operated side, knee extension range of motion on the non-operated side, and Somatic Focus, a subscale of the Tampa Scale for Kinesiophobia (short version). The model had a sensitivity of 50.0 %, a specificity of 98.7 %, a positive predictive value of 92.9 %, a positive likelihood ratio of 37.5, and an area under the receiver operating characteristic curve of 0.853.

CONCLUSION

We have developed a CPR that, with some accuracy, predicts the mobility outcomes of patients after TKA. This CPR may be useful for predicting postoperative mobility and clinical goal setting.

Obesity Severity Predicts Patient Dissatisfaction After Total Knee Arthroplasty

BACKGROUND

Patient dissatisfaction has been reported in 15 to 20% of traditional total knee arthroplasty (TKA) procedures. While contemporary improvements may have positive effects on patient satisfaction, these may be offset by increasing obesity prevalence among patients who have knee osteoarthritis. We performed this study to determine whether obesity severity impacts patient-reported TKA satisfaction.

METHODS

We compared patient demographic characteristics, preoperative expectations, preoperative and minimum 1-year postoperative patient-reported outcome measures as well as postoperative satisfaction level among 229 patients (243 TKAs) who had World Health Organization (WHO) Class II or III obesity (group A), and 287 patients (328 TKAs) who had WHO classifications of normal weight, overweight, or Class I obesity (group B).

RESULTS

Group A patients were younger and had more severe preoperative back and contralateral knee pain, more frequent preoperative opioid medication use, and lower preoperative and postoperative patient-reported outcome measures (P < .01). A similar proportion of patients in both groups expected at least 75% improvement (68.5 versus 73.2%, P = .27). While satisfaction was higher than traditional reporting for both groups (89.4 versus 92.6%, P = .19), group A patients were less likely to be highly satisfied (68.1 versus 78.5%, P = .04) and were more likely to be highly dissatisfied (5.1 versus 0.9%, P < .01).

CONCLUSIONS

Patients who have Class II and III obesity report greater TKA dissatisfaction. Additional studies should help determine whether specific implant designs or surgical techniques may improve patient satisfaction or whether preoperative counseling should incorporate lower satisfaction expectations for patients who have WHO Class II or III obesity.

The Benefit in Patient-Reported Outcomes After Total Knee Arthroplasty was Comparable Across Income Quartiles

BACKGROUND

Few studies have assessed how socioeconomic status (SES) influences patient-reported outcomes (PROMs) after total knee arthroplasty (TKA). This study evaluated the impact of patient median ZIP code income levels on PROMs after TKA.

METHODS

We retrospectively reviewed patients at our institution undergoing primary, unilateral TKA from 2017 to 2020. Patients who did not have one-year postoperative PROMs were excluded. Patients were stratified based on the quartile of their home ZIP code median income from United States Census Bureau data. There were 1,267 patients included: 98 in quartile 1 (median income ≤ $46,308) (7.7%); 126 in quartile 2 (median income $46,309-$57,848) (10.0%); 194 in quartile 3 (median income $57,849-$74,011) (15.7%); and 849 in quartile 4 (median income ≥ $74,012) (66.4%). We collected baseline demographic data, 2-year outcomes, and PROMs preoperatively, as well as at 12 weeks and one year, postoperatively.

RESULTS

The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was significantly higher in quartile 4 preoperatively (P < .001), 12 weeks postoperatively (P < .001), and one year postoperatively (P < .001). There were no significant differences in delta improvements of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement from preoperative to 12 weeks or one year postoperatively. There were no significant differences in lengths of stay, discharge dispositions, readmissions, or revisions.

CONCLUSION

Patients from lower income areas have slightly worse knee function preoperatively and worse outcomes following TKA. However, improvements in PROMs throughout the first year postoperatively are similar across income quartiles, suggesting that patients from lower income quartiles achieve comparable therapeutic benefits from TKA.

LEVEL III EVIDENCE

Retrospective Cohort Study.

The utility of machine learning algorithms for the prediction of patient-reported outcome measures following primary hip and knee total joint arthroplasty

BACKGROUND

Patient-reported outcome measures (PROMs) are increasingly used as quality benchmark in total hip and knee arthroplasty (THA; TKA) due to bundled payment systems that aim to provide a patient-centered, value-based treatment approach. However, there is a paucity of predictive tools for postoperative PROMs. Therefore, this study aimed to develop and validate machine learning models for the prediction of numerous patient-reported outcome measures following primary hip and knee total joint arthroplasty.

METHODS

A total of 4526 consecutive patients (2137 THA; 2389 TKA) who underwent primary hip and knee total joint arthroplasty and completed both pre- and postoperative PROM scores was evaluated in this study. The following PROM scores were included for analysis: HOOS-PS, KOOS-PS, Physical Function SF10A, PROMIS SF Physical and PROMIS SF Mental. Patient charts were manually reviewed to identify patient demographics and surgical variables associated with postoperative PROM scores. Four machine learning algorithms were developed to predict postoperative PROMs following hip and knee total joint arthroplasty. Model assessment was performed through discrimination, calibration and decision curve analysis.

RESULTS

The factors most significantly associated with the prediction of postoperative PROMs include preoperative PROM scores, Charlson Comorbidity Index, American Society of Anaesthesiology score, insurance status, age, length of hospital stay, body mass index and ethnicity. The four machine learning models all achieved excellent performance across discrimination (AUC > 0.83), calibration and decision curve analysis.

CONCLUSION

This study developed machine learning models for the prediction of patient-reported outcome measures at 1-year following primary hip and knee total joint arthroplasty. The study findings show excellent performance on discrimination, calibration and decision curve analysis for all four machine learning models, highlighting the potential of these models in clinical practice to inform patients prior to surgery regarding their expectations of postoperative functional outcomes following primary hip and knee total joint arthroplasty.

LEVEL OF EVIDENCE

Level III, case control retrospective analysis.

Changes in epidemiological characteristics of knee arthroplasty in eastern, northern and central China between 2011 and 2020

OBJECTIVE

To explore changes in the epidemiological and clinical characteristics of patients who underwent knee arthroplasty (KA) over a 10-year period in China.

METHODS

Medical records of patients with knee osteoarthritis (KOA), who underwent primary unilateral KA in 5 level I center hospitals in China between January 2011 and December 2020, were retrospectively reviewed and analyzed. To more clearly define changes over the years, patients were divided into two groups according to time of admission at 5-year intervals. Age, sex, body mass index (BMI), Kellgren-Lawrence (K-L) classification, comorbid diseases, surgical procedures, hospital stay, and hospitalization costs were compared between the two groups.

RESULTS

A total of 23,610 patients with KOA (5400 male and 18,210 females; mean age: 65.7 ± 7.6 years) who underwent primary unilateral KA were included. The number of KAs increased in recent years (group A, n = 7606 vs. group B, n = 16,004). Significant differences were noted in age, sex, BMI, K-L classification, comorbidities, surgical procedures, hospital stay, and hospitalization costs between the two periods (P < 0.05). More than three-quarters of KA cases involved females, and the age at surgery tended to be younger than that reported in foreign countries. In group B, the proportion of overweight and grade III, number of comorbidities, and unicompartmental knee arthroplasty patients increased compared to that in group A; however, hospitalization costs and length of hospital stay decreased.

CONCLUSIONS

Results suggested that the epidemiological characteristics of patients undergoing KA have changed over time. An analysis of the epidemiological characteristics of patients undergoing KA treatment may provide a scientific basis for the prevention and control of KOA.

Interactive Combinations Between Gait Speed and Physical Function at Acute Phase Can Predict the Physical Activity at 2 Years After Total Knee Arthroplasty Using Classification and Regression Tree Analysis

OBJECTIVE

To clarify the interactive combinations of various clinical factors associated with physical activity (PA) at 2 years after total knee arthroplasty (TKA) using classification and regression tree (CART) analysis.

DESIGN

A retrospective cohort study.

SETTING

A single university hospital.

PARTICIPANTS

286 patients who underwent TKA (N=286).

MAIN OUTCOME MEASURES

PA was assessed preoperatively, 3 weeks, and 2 years after TKA. Physical functions, namely, 10 m walking test (10MWT), timed Up and Go test, 1-leg standing time, isometric knee extension and flexion strength, knee joint stability, knee pain, femora-tibial angle, and the passive knee extension and flexion angle, were measured before surgery as a baseline and 3 weeks after TKA as acute phase. CART analysis was conducted to clarify the interactive combinations that accurately predict the PA at 2 years after TKA.

RESULTS

The results of CART analysis indicated that gait speed (≥1.05 m/s) at the acute phase after TKA was the primal predictor for the postoperative PA at 2 years. The highest postoperative PA at 2 years was determined by gait speed (≥1.05 m/s) and PA (>74.5) at the acute phase. The PA at baseline and at acute phase, as well as the body mass index were also selected as predictors of postoperative PA at 2 years.

CONCLUSION

The present study suggested that acquiring gait speed (≥1.05 m/s) and PA (>74.5) in the postoperative acute phase is the predictive of a high PA at 2 years after TKA.

Comparison of the Journey II bicruciate stabilised (JII-BCS) and GENESIS II total knee arthroplasty for functional ability and motor impairment: the CAPAbility, blinded, randomised controlled trial

OBJECTIVES

To determine if a newer design of total knee replacement (TKR) (Journey II BCS) produces superior patient-reported outcomes scores and biomechanical outcomes than the older, more established design (Genesis II).

SETTING

Patients were recruited from an NHS University Hospital between July 2018 and October 2019 with surgery at two sites. Biomechanical and functional capacity measurements were at a University Movement and Exercise Laboratory.

PARTICIPANTS

80 participants undergoing single-stage TKR.

INTERVENTIONS

Patients were randomised to receive either the Journey II BCS (JII-BCS) or Genesis II TKR.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was the Oxford Knee Score (OKS), at 6 months. Secondary outcomes were: OKS Activity and Participation Questionnaire, EQ-5D-5L and UCLA Activity scores, Timed Up and Go Test, 6 min walk test, lower limb kinematics and lower limb muscle activity during walking and balance.

RESULTS

This study found no difference in the OKS between groups. The OKS scores for the JII-BCS and Genesis II groups were mean (SD) 42.97 (5.21) and 43.13 (5.20) respectively, adjusted effect size 0.35 (-2.01,2.71) p=0.771In secondary outcome measures, the Genesis II group demonstrated a significantly greater walking range-of-movement (50.62 (7.33) vs 46.07 (7.71) degrees, adjusted effect size, 3.14 (0.61,5.68) p=0.02) and higher peak knee flexion angular velocity during walking (mean (SD) 307.69 (38.96) vs 330.38 (41.40) degrees/second, adjusted effect size was 21.75 (4.54,38.96), p=0.01) and better postural control (smaller resultant centre of path length) during quiet standing than the JII-BCS group (mean (SD) 158.14 (65.40) vs 235.48 (176.94) mm, adjusted effect size, 59.91 (-105.98, -13.85) p=0.01.).

CONCLUSIONS

In this study population, the findings do not support the hypothesis that the Journey II BCS produces a better outcome than the Genesis II for the primary outcome of the OKS at 6 months after surgery.

TRIAL REGISTRATION NUMBER

ISRCTN32315753.

SMART choice (knee) tool: a patient-focused predictive model to predict improvement in health-related quality of life after total knee arthroplasty

BACKGROUND

Current predictive tools for TKA focus on clinicians rather than patients as the intended user. The purpose of this study was to develop a patient-focused model to predict health-related quality of life outcomes at 1-year post-TKA.

METHODS

Patients who underwent primary TKA for osteoarthritis from a tertiary institutional registry after January 2006 were analysed. The primary outcome was improvement after TKA defined by the minimal clinically important difference in utility score at 1-year post-surgery. Potential predictors included demographic information, comorbidities, lifestyle factors, and patient-reported outcome measures. Four models were developed, including both conventional statistics and machine learning (artificial intelligence) methods: logistic regression, classification tree, extreme gradient boosted trees, and random forest models. Models were evaluated using discrimination and calibration metrics.

RESULTS

A total of 3755 patients were included in the study. The logistic regression model performed the best with respect to both discrimination (AUC = 0.712) and calibration (intercept = -0.083, slope = 1.123, Brier score = 0.202). Less than 2% (n = 52) of the data were missing and therefore removed for complete case analysis. The final model used age (categorical), sex, baseline utility score, and baseline Veterans-RAND 12 responses as predictors.

CONCLUSION

The logistic regression model performed better than machine learning algorithms with respect to AUC and calibration plot. The logistic regression model was well calibrated enough to stratify patients into risk deciles based on their likelihood of improvement after surgery. Further research is required to evaluate the performance of predictive tools through pragmatic clinical trials.

LEVEL OF EVIDENCE

Level II, decision analysis.

Effects of Comorbidities on Pain and Function After Total Hip Arthroplasty

Background

The growing number of patients undergoing total hip arthroplasty (THA) and postoperative outcomes receive increasing attention from doctors and patients. This study aimed to elucidate the effects of comorbidities on postoperative function, pain, complications, readmission rate, and mortality.

Methods

We included consecutive patients who underwent primary unilateral THA between 2017 and 2019. The Charlson comorbidity index (CCI) and the WOMAC and SF-36 (physical function, body pain) scales were assessed preoperatively and at 3, 6, 12, and 24 months postoperatively. The complications, 30-day readmission, and mortality rates assessed the impact of comorbidities and their changes over time on the WOMAC and SF-36 scores during follow-up. We used mixed model linear regression to examine the association of worsening comorbidity post-THA with change in WOMAC and SF-36 scores in the subsequent follow-up periods, controlling for age, length of follow-up, and repeated observations.

Results

This study included 468 patients, divided into four groups based on comorbidity burden (CCI-0, 1, 2, and ≥3). The physiological function recovery and pain scores in the CCI ≥ 3 group were inferior to the other groups and took longer than the other groups (6 vs. 3 months) to reach their best level. The four groups preoperative waiting times were 2.41 ± 0.74, 2.97 ± 0.65, 3.80 ± 0.53, and 5.01 ± 0.71 days, respectively. The complications, 30-day readmission, and 1-year mortality rates for the overall and the CCI ≥ 3 group were 1.92% and 4.69%, 0.85% and 2.01%, and 0.43% and 1.34%, respectively, with no mortality in the other groups.

Conclusion

Patients with higher CCI were more susceptible to physical function and pain outcome deterioration, experienced longer waiting time before surgery, took longer to recover, and had higher rates of complications, 30-day readmission, and mortality after THA. Older age in the group led to a greater impact.

Is modular control related to functional outcomes in individuals with knee osteoarthritis and following total knee arthroplasty?

BACKGROUND

Individuals who undergo total knee arthroplasty (TKA) for treatment of knee osteoarthritis often experience suboptimal outcomes. Investigation of neuromuscular control strategies in these individuals may reveal factors that contribute to these functional deficits. The purpose of this pilot study was to determine the relationship between patient function and modular control during gait before and after TKA.

METHODS

Electromyography data from 36 participants (38 knees) were collected from 8 lower extremity muscles on the TKA-involved limb during ≥5 over-ground walking trials before (n = 30), 6-months after (n = 26), and 24-months after (n = 13) surgery. Muscle modules were estimated using non-negative matrix factorization. The number of modules was determined from 500 resampled trials.

RESULTS

A higher number of modules was related to better performance-based and patient-reported function before and 6-months after surgery. Participants with organization similar to healthy, age-matched controls trended toward better function 24-months after surgery, though these results were not statistically significant. We also observed plasticity in the participants' modular control strategies, with 100% of participants who were present before and 24-months after surgery (10/10) demonstrating changes in the number of modules and/or organization of at least 1 module.

CONCLUSIONS

This pilot work suggests that functional improvements following TKA may initially present as increases in the number of modules recruited during gait. Subsequent improvements in function may present as improved module organization.

NOTEWORTHY

This work is the first to characterize motor modules in TKA both before and after surgery and to demonstrate changes in the number and organization of modules over the time course of recovery, which may be related to changes in patient function. The plasticity of modular control following TKA is a key finding which has not been previously documented and may be useful in predicting or improving surgical outcomes through novel rehabilitation protocols.

Effects of physical activity interventions using wearables to improve objectively-measured and patient-reported outcomes in adults following orthopaedic surgical procedures: A systematic review

OBJECTIVE

To synthesize evidence on physical activity interventions that used wearables, either alone or in combination with education or rehabilitation, in adults following orthopaedic surgical procedures.

METHODS

PubMed, CINAHL, PsycINFO and EMBASE were searched for randomized controlled trials of wearable-based interventions from each database's inception to August 2021 in patients undergoing orthopaedic surgery. Relevant outcomes included physical activity, physical function, pain, psychological distress, or general health. PEDro scale scoring ranges from 0 to 10 and was used to appraise studies as high (≥7), moderate (5-6), or poor (<5) quality.

RESULTS

Of 335 articles identified, 6 articles met eligibility criteria. PEDro scores ranged from 2 to 6, with 3 studies of moderate quality and 3 of poor quality. Studies included patients undergoing total knee (number; n = 4) or total knee or hip (n = 1) arthroplasty and lumbar disc herniation surgery (n = 1). In addition to wearables, intervention components included step diary (n = 2), motivational interviewing (n = 1), goal setting (n = 2), tailored exercise program (n = 2), or financial incentives (n = 1). Interventions were delivered in-person (n = 2), remotely (n = 3) or in a hybrid format (n = 1). Intervention duration ranged from 6 weeks to 6 months. Compared to controls, 3 moderate quality studies reported greater improvement in steps/day; however, 1 moderate and 2 poor quality studies showed no between-group difference in physical function, pain, or quality of life. No serious adverse events related to the use of wearable were reported.

CONCLUSIONS

The effects of physical activity interventions using wearables, either delivered in-person or remotely, appear promising for increasing steps per day after joint arthroplasty; however, this finding should be viewed with caution since it is based on 3 moderate quality studies. Further research is needed to determine the therapeutic effects of using wearables as an intervention component in patients undergoing other orthopaedic surgical procedures.

TRIAL REGISTRATION

PROSPERO Registration Number: CRD42020186103.

Gender Influences on Shoulder Arthroplasty

PURPOSE OF REVIEW

As the incidence of shoulder arthroplasty continues to increase, there is growing interest in patient-based factors that may predict outcomes. Based on existing literature demonstrating gender-based disparities following total hip and knee arthroplasty, gender may also influence shoulder arthroplasty. The purpose of this review is to discuss the recent literature on the influence of gender on shoulder arthroplasty, focusing on differences in preoperative parameters, perioperative complications, and postoperative outcomes.

RECENT FINDINGS

While both female and male patients generally benefit from shoulder arthroplasty, several differences may exist in preoperative factors, acute perioperative complications, and postoperative outcomes. Preoperatively, female patients undergo shoulder arthroplasty at an older age compared to their male counterparts. They may also have greater levels of preoperative disability and different preoperative expectations. Perioperatively, female patients may be at increased risk of extended length of stay, postoperative thromboembolic events, and blood transfusion. Postoperatively, female patients may achieve lower postoperative functional scores and decreased range of motion compared to male patients. Differences in postoperative functional scores may be influenced by gender-based differences in activities of daily living. Finally, female patients may be at greater risk for periprosthetic fracture and aseptic loosening while male patients appear to be at greater risk for periprosthetic infection and revision surgery. Current literature on the influence of gender on shoulder arthroplasty is limited and conflicting. Further research is necessary to delineate how gender affects patients at the pre- and postoperative levels to better inform decision-making and outcomes.

The Impact of Total Joint Arthroplasty on Long-Term Physical Activity: A Secondary Analysis of the Health and Retirement Study

OBJECTIVE

Physical inactivity is the fourth-leading cause of global mortality and is prevalent among people with lower extremity osteoarthritis. Lower extremity osteoarthritis is the most common arthritis type afflicting older adults, and total joint arthroplasty (TJA) performed to address the condition is Medicare's largest annual expense. Despite TJA intervention to address the disabling effects of osteoarthritis, physical activity (PA) level remains stable 6 months after TJA; however, the effect of TJA on long-term PA $(\ge$2 y) in a representative sample of older adults is unknown. The purpose of this study was to test the hypothesis that PA would remain stable in the long term.

METHODS

In this longitudinal observational study, a probability-weighted difference-in-differences analysis was conducted to observe the predictive margins of nontraumatic hip or knee TJA on levels of vigorous and moderate PA after 2 years. A combined Health and Retirement Study data set of community-dwelling adults who were >55 years old, had symptomatic osteoarthritis, and were in need of TJA between 2008 and 2018 (N = 4652) was used.

RESULTS

TJA was not associated with vigorous PA ($\delta$ = 2.37; SE = 5.23) or moderate PA ($\delta$ = -2.84; SE = 7.76) after 2 years.

CONCLUSION

TJA was not associated with increased long-term PA in older adults with osteoarthritis.

IMPACT

Physical therapists should not assume that there will be a natural increase in PA after functional recovery from TJA procedures. Older adults with lower extremity osteoarthritis may benefit from PA screening and promotion practices in physical therapy services.

LAY SUMMARY

Receiving a total joint replacement does not lead to increased physical activity levels 2 years after surgery.

Osteoarthritis Progression: Mitigation and Rehabilitation Strategies

Osteoarthritis is the most common form of arthritis and is a substantial burden for patients with the disease. Currently, there is no cure for osteoarthritis, but many emerging therapies have been developed to aid in the mitigation of disease progression. When osteoarthritis reaches the end-stage of disease many patients undergo total joint arthroplasty to improve quality of life, yet some experience persistent pain and mobility limitations for extended periods following surgery. This review highlights recent therapeutic advancements in osteoarthritis treatment consisting of pharmacologics, nutraceuticals, biologics, and exercise while emphasizing the current state of post-arthroplasty rehabilitation.

Gait mechanics are influenced by quadriceps strength, age, and sex after total knee arthroplasty

Although most patients are satisfied with outcomes after total knee arthroplasty (TKA), many retain preoperative altered gait mechanics. Identifying patient characteristics associated with gait mechanics will improve rehabilitation strategies and enhance our understanding of movement disorders. Therefore, the purpose of this study was to identify which patient characteristics are related to gait mechanics in the surgical limb during walking post-TKA. Patient characteristics included age, body mass, sex, quadriceps strength, self-reported function, and knee pain. General linear regression was used to compare patient characteristics associated with gait mechanics, after controlling for gait speed, functional capacity and time from surgery. We tested 191 patients cross-sectionally at 6-24 months after primary, unilateral TKA. Quadriceps weakness in the surgical limb was associated with less peak vertical ground reaction force (PvGRF) (β = .245, p = .044), knee extension moment (β = .283, p = .049), and knee extension excursion (β = .298, p = .038). Older age (β = .168, p = .050) was associated with less PvGRF. Quadriceps strength in the nonsurgical limb (β = -.357, p = .021) was associated with greater knee extension excursion in the surgical limb. Females with TKA (β = -.276, p = .007) had less knee flexion excursion compared to males. Faster gait speed was also associated with greater PvGRF (β = .585, p < .001), knee extensor moment (β = .481, p < .001), and knee flexion excursion (β = .318, p < .001). Statement of Clinical Significance: This study showed quadriceps weakness, slower gait speed, older age and being female were related to altered gait mechanics post-TKA. These findings will help clinicians better educate patients and develop targeted interventions for improving care in patients post-TKA.

The influence of expectation modification in knee arthroplasty on satisfaction of patients: a randomized controlled trial

AIMS

Meeting preoperative expectations is known to be of major influence on postoperative satisfaction after total knee arthroplasty (TKA). Improved management of expectation, resulting in more realistic expectations can potentially lead to higher postoperative satisfaction. The objective of this study was to assess the effect of an additional preoperative education module, addressing realistic expectations for long-term functional recovery, on postoperative satisfaction and expectation fulfilment.

METHODS

In total, 204 primary TKA patients with osteoarthritis were enrolled in this randomized controlled trial (RCT). Patients were allocated to either usual preoperative education (control group) or usual education plus an additional module on realistic expectations (intervention group). Primary outcome was being very satisfied (numerical rating scale for satisfaction ≥ 8) with the treatment result at 12 months' follow-up. Other outcomes were change in preoperative expectations and postoperative expectation fulfilment.

RESULTS

A total of 187 patients (91.7%) were available for analysis at follow-up. In the intention-to-treat analysis, 58.5% (55/94) of patients were very satisfied with the treatment result in the control group, and 69.9% (65/93) of patients in the intervention group (adjusted odds ratio (AOR) 1.72, 95% confidence interval (CI) 0.90 to 3.29). A per-protocol analysis for patients who attended the education session (92.0%, n = 172) showed that 56.9% (49/86) of patients were very satisfied in the control group and 74.4% (61/86) in the intervention group (AOR 2.44, 95% CI 1.21 to 4.91). After preoperative education, the expectation scores in the intervention group were significantly lower (mean difference -6.9 (95% CI -10.2 to -3.6)) and did not alter in the control group (mean difference 0.5 (95% CI -2.9 to 3.9)). Overall, fulfilment of expectations at 12 months was significantly higher in the intervention group (mean difference 11.4% (95% CI 2.3 to 20.5)).

CONCLUSION

Improved preoperative patient education can modify patient expectations, resulting in higher postoperative fulfilment of expectation and higher satisfaction in the group that attended the preoperative education. This is the first RCT to confirm the potential of improved expectation management on satisfaction after TKA. Cite this article: Bone Joint J 2021;103-B(4):619-626.

Three distinct recovery patterns following primary total knee arthroplasty: dutch arthroplasty register study of 809 patients

PURPOSE

Total knee arthroplasty (TKA) is usually effective, although not all patients have satisfactory outcomes. This assumes distinct recovery patterns might exist. Little attention has been paid to determine which patients have worse outcomes. This study attempts to distinguish specific recovery patterns using the Oxford knee score (OKS) during the first postoperative year. The secondary aim was to explore predictors of less favourable recovery patterns.

METHODS

Analysis of patients in the Dutch Arthroplasty Register (LROI) with unilateral primary TKA. Data collected up to one year postoperative was used. To identify subgroups of patients based on OKS, latent class growth modeling (LCGM) was used. Moreover, multivariable multinomial logistic regression analysis was used to explore predictors of class membership.

RESULTS

809 Patients completed three OKS during the first year postoperative and were included. LCGM identified 3 groups of patients; 'high risers' (most improvement during first 6-months, good 12-month scores 77%), 'gradual progressors' (continuous improvement during the first year 13%) and 'non responders' (initial improvement and subsequent deterioration to baseline score 10%). Predictors of least favourable class membership (OR, 95%CI) are EQ-5D items: VAS health score (0.83, 0.73-0.95), selfcare (2.22, 1.09-4.54) and anxiety/depression (2.45, 1.33-4.52).

CONCLUSION

Three recovery patterns after TKA were distinguished; 'high risers', 'gradual progressors' and 'non responders'. Worse score on EQ-5D items VAS health, selfcare, and anxiety/depression were correlated with the least favourable 'non responders' recovery pattern.

African American Patients Have Improved Functional Gains and Comparable Clinical Outcomes to Caucasian Patients After Total Hip and Knee Arthroplasty

BACKGROUND

With the increasing popularity of alternative payment models, minorities who use more postacute care resources may face difficulties with access to quality total hip arthroplasty (THA) and total knee arthroplasty (TKA) care. The purpose of this study is to compare differences in perioperative complications and functional outcomes between African American and Caucasian patients undergoing THA and TKA.

METHODS

We reviewed a consecutive series of all primary THA and TKA patients at our institution from 2015 to 2018. Demographics, comorbidities, 90-day complications, readmissions, Veterans Rand 12-Item Health Survey (VR-12), Hip disability Osteoarthritis Outcome Score (HOOS), and Knee injury and Osteoarthritis Outcome Scores (KOOS) were compared between African American and Caucasian patients. A multivariate analysis was performed to control for confounding variables.

RESULTS

Of the 5284 patients included in the study, 1041 were African American (24.5%). Although African American patients had lower preoperative HOOS/KOOS (33.5 vs 45.1, P < .001) and mental VR-12 scores (37.8 vs 51.5, P < .001) compared with Caucasian patients, there was no clinical difference at 1 year in HOOS/KOOS (50.2 vs 50.4), mental VR-12 (55.0 vs 52.6), or physical VR-12 scores (39.5 vs 39.8). When controlling for demographics and medical comorbidities, African American race was associated with increased rehabilitation facility discharge (odds ratio, 1.69; P < .001) but no difference in readmissions or complications.

CONCLUSION

Although African American patients had lower preoperative functional scores, they made improved postoperative gains when compared with Caucasian patients. Although there was no difference in postoperative complications, further studies should assess social causes for the increase in rehabilitation utilization rates in minority patients.

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

BACKGROUND

Concerns exist that minorities who utilize more resources in an episode-of-care following total hip (THA) and knee arthroplasty (TKA) may face difficulties with access to quality arthroplasty care in bundled payment programs. The purpose of this study is to determine if African American patients undergoing TKA or THA have higher episode-of-care costs compared to Caucasian patients.

METHODS

We queried Medicare claims data for a consecutive series of 7310 primary TKA and THA patients at our institution from 2015 to 2018. We compared patient demographics, comorbidities, readmissions, and 90-day episode-of-care costs between African American and Caucasian patients. A multivariate regression analysis was performed to identify the independent effect of race on episode-of-care costs.

RESULTS

Compared to Caucasians, African Americans were younger, but had higher rates of pulmonary disease and diabetes. African American patients had increased rates of discharge to a rehabilitation facility (20% vs 13%, P < .001), with higher subacute rehabilitation ($1909 vs $1284, P < .001), home health ($819 vs $698, P = .022), post-acute care ($5656 vs $4961, P = .008), and overall 90-day episode-of-care costs ($19,457 vs $18,694, P = .001). When controlling for confounding comorbidities, African American race was associated with higher episode-of-care costs of $440 (P < .001).

CONCLUSION

African American patients have increased episode-of-care costs following THA and TKA when compared to Caucasian patients, mainly due to increased rates of home health and rehabilitation utilization. Further study is needed to identify social variables that can help reduce post-acute care resources and prevent reduction in access to arthroplasty care in bundled payment models.

Is there an optimal age for total knee arthroplasty?: A systematic review

PURPOSE

The purpose of this systematic review was to elucidate the optimal age for patients undergoing total knee arthroplasty (TKA), to optimize the balance between the benefits and risks by analyzing patient-reported outcome measurements (PROM), revision rate, and mortality according to age.

MATERIALS AND METHODS

A rigorous and systematic approach was used and each of the selected studies was evaluated for methodological quality. Data were extracted according to the following: study design, patients enrolled, patient age at the time of surgery, follow-up period, PROM, revision rate, and mortality.

RESULTS

Thirty-nine articles were included in the final analysis. The results were inconsistent in the PROM analysis, but there was consensus that PROM were good in patients in their 70s . In the revision rate analysis, there was consensus that the revision rate tends to increase in TKA in younger patients, but no significant difference was observed in patients > 70 years of age. In the mortality analysis, there was consensus that the mortality was not significantly different in patients < 80 years of age, but tended to increase with age.

CONCLUSION

This systematic review shows that the PROM were good when TKA was performed in patients between 70 and 80 years of age; the best PROM could be achieved around 70 years of age, and no significant difference in the revision or mortality rates was observed between 70 and 80 years of age; however, mortality tended to increase with age. Therefore, the early 70s could be recommended as an optimal age to undergo TKA.

Why are patients dissatisfied following a total knee replacement? A systematic review

BACKGROUND

Although total knee replacement (TKR) is an effective intervention for end-stage arthritis of the knee, a significant number of patients remain dissatisfied following this procedure. Our aim was to identify and assess the factors affecting patient satisfaction following a TKR.

MATERIALS AND METHODS

In accordance with the PRISMA guidelines, two reviewers searched the online databases for literature describing factors affecting patient satisfaction following a TKR. The research question and eligibility criteria were established a priori. Any clinical outcome study that described factors relating to overall satisfaction after primary TKR was included. Quality assessment for the included studies was performed by two accredited orthopaedic surgeons experienced in clinical research.

RESULTS

The systematic review identified 181 relevant articles in total. A history of mental health problems was the most frequently reported factor affecting patient satisfaction (13 reportings). When the results of the quality assessment were taken into consideration, a negative history of mental health problems, use of a mobile-bearing insert, patellar resurfacing, severe pre-operative radiological degenerative change, negative history of low back pain, no/less post-operative pain, good post-operative physical function and pre-operative expectations being met were considered to be important factors leading to better patient satisfaction following a TKR.

CONCLUSION

Surgeons performing a TKR should take these factors into consideration prior to deciding whether a patient is suitable for a TKR. Secondarily, a detailed explanation of these factors should form part of the process of informed consent to achieve better patient satisfaction following TKR. There is a great need for a unified approach to assessing satisfaction following a TKR and also the time at which satisfaction is assessed.

Effect of Group-Based Outpatient Physical Therapy on Function After Total Knee Replacement: Results From a Multicenter Randomized Controlled Trial

Objective

To evaluate the long‐term clinical effectiveness of a novel group‐based outpatient physical therapy (PT) following total knee replacement (TKR).

Methods

In this 2‐center, unblinded, superiority, randomized controlled trial, 180 patients on a waiting list for primary TKR due to osteoarthritis were randomized to a 6 session group‐based outpatient PT intervention and usual care (n = 89) or usual care alone (n = 91). The primary outcome was patient‐reported functional ability measured by the Lower Extremity Functional Scale at 12 months postoperative. Secondary outcomes included knee symptoms, depression, anxiety, and satisfaction. Questionnaires were completed preoperatively and at 3, 6, and 12 months postoperatively.

Results

The mean difference in function between groups was 4.47 (95% confidence interval [95% CI] 0.20, 8.75; P = 0.04) at 12 months postoperative, favoring the intervention. The mean difference in function between groups decreased over time, from 8.1 points at 3 months (95% CI 3.8, 12.4; P < 0.001) to 5.4 (95% CI 1.1, 9.8; P = 0.015) at 6 months postoperative. There were no clinically relevant differences in any secondary outcomes between groups, although patients in the intervention group were more likely to be satisfied with their PT. No serious adverse events related to the intervention were reported.

Conclusion

Supplementing usual care with this group‐based outpatient PT intervention led to improvements in function at 12 months after TKR, although the magnitude of the difference was below the minimum clinically important difference of 9 points. However, patient satisfaction was higher in the intervention group, and there was some evidence of clinically relevant improvements in function at 3 months.

A comparative study of clinical effect of total knee arthroplasty in the treatment of primary osteoarthritis and osteoarthritis of Kashin-Beck disease

OBJECTIVE

To evaluate the clinical efficacy of total knee arthroplasty (TKA) in the treatment of primary osteoarthritis (OA) and osteoarthritis of Kashin-Beck disease (KBD).

METHODS

This study enrolled 77 KBD patients (77 knees, KBD-TKA) and 75 OA patients (75 knees, OA-TKA) who underwent TKA from September 2008 to June 2018. Clinical assessments for each patient were performed pre-operatively and last follow-up. The efficacy measures included the visual analogue scale (VAS) pain score, range of motion (ROM), Hospital for Special Surgery (HSS) score, and short form 36 Health Survey (SF-36) as well as related influencing factors between the two groups.

RESULTS

All patients were followed up; the follow-up time of KBD-TKA was 14-132 months, with an average of 72.68 ± 37.55 months; OA-TKA was 15-120 months, with an average of 49.2 ± 28.91 months. There was no difference in pre-operative VAS score (7.29 vs. 7.24) and SF-36 (PCS) score (4.87 vs. 5.49) between KBD-TKA and OA-TKA (P > 0.05), while compared with OA, KBD-TKA had significantly worse pre-operative ROM (75.48° vs. 82.87°), HSS score (36.40 vs. 41.84), and SF-36 (MCS) score (26.28 vs. 28.73) (P < 0.05). At the final follow-up, there was no significant difference in VAS score (1.13 vs. 1.16), ROM (105.79 vs. 105.79), and HSS score (92.06 vs. 92.25) between KBD-TKA and OA-TKA (P > 0.05), while compared with OA, KBD-TKA had significantly worse SF-36 (PCS) score (36.90 vs. 42.00) and SF-36 (MCS) score (55.16 vs. 59.70) (P < 0.05). In a multivariate regression, controlling for multiple potential confounders, diagnosis of KBD was associated with poor quality of life after surgery, whereas pre-operative pain was specifically associated with post-operative pain. However, preoperative gender, age, BMI, and the angles of knee prosthesis (before and after surgery) were not associated with post-operative outcome.

CONCLUSION

Patients with KBD undergoing primary TKA have excellent outcomes, comparable with OA at the final follow-up, in spite of worse pre-operative ROM, HSS score, and SF-36(MCS) score. However, KBD patients are worse than OA in terms of general health. Pre-operative age, gender, BMI, and the angles of knee prosthesis were not the factors influencing the clinical efficacy of TKA. The diagnosis of KBD was an independent risk factor for poor quality of life after TKA. Pre-operative pain was a clinically important predictor of outcome.

CAPAbility: comparison of the JOURNEY II Bi-Cruciate Stabilised and GENESIS II total knee arthroplasty in performance and functional ability: protocol of a randomised controlled trial

Background

Osteoarthritis of the knee is a common condition that is expected to rise in the next two decades leading to an associated increase in total knee replacement (TKR) surgery. Although there is little debate regarding the safety and efficacy of modern TKR, up to 20% of patients report poor functional outcomes following surgery. This study will investigate the functional outcome of two TKRs; the JOURNEY II Bi-Cruciate Stabilised knee arthroplasty, a newer knee prosthesis designed to provide guided motion and improve knee kinematics by more closely approximating a normal knee, and the GENESIS II, a proven existing design.

Aim

To compare the change in Patient-reported Outcome Measures (PROMs) scores of the JOURNEY II BCS and the GENESIS II from pre-operation to 6 months post operation.

Methods

CAPAbility is a pragmatic, blinded, two-arm parallel, randomised controlled trial recruiting patients with primary osteoarthritis due to have unilateral TKR surgery across two UK hospitals. Eligible participants (n = 80) will be randomly allocated to receive either the JOURNEY II or the GENESIS II BCS knee prosthesis. Baseline measures will be taken prior to surgery. Patients will be followed at 1 week, 6 to 8 weeks and 6 months post-operatively. The primary outcome is the Oxford Knee Score (OKS) at 6 months post-operatively. Secondary outcomes include: other PROMs, biomechanical, radiological (computerised tomography, (CT)), clinical efficacy and safety outcomes. An embedded qualitative study will also investigate patients’ perspectives via interview pre and post surgery on variables known to affect the outcome of TKR surgery. A sub-sample (n = 30) will have additional in-depth interviews to explore the themes identified. The surgeons’ perspectives on the operation will be investigated by a group interview after all participants have undergone surgery.

Discussion

This trial will evaluate two generations of TKR using PROMS, kinematic and radiological analyses and qualitative outcomes from the patient perspective.

Trial registration

International Standard Randomised Controlled Trials Number Registration, ID: ISRCTN32315753. Registered on 12 December 2017.

Polymyositis has minimal effect on primary total knee or hip arthroplasty outcomes

To assess whether polymyositis is associated with more complications and higher healthcare utilization after total knee or hip arthroplasty (TKA/THA). Using the 1998-2014 U.S. National Inpatient Sample data, we performed multivariable-adjusted logistic regression analyses to assess the association of polymyositis with in-hospital complications (implant infection, revision, transfusion, mortality) and healthcare utilization (hospital charges, length of hospital stay, discharge to non-home setting), controlling for important covariates and confounders. Sensitivity analyses additionally adjusted the main models for hospital location/teaching status, bed size, and region. Of the 4,116,485 THAs and 8,127,282 TKAs, 853 people with polymyositis had THAs (0.02%) and 1038 had TKAs (0.01%). In multivariable-adjusted analyses, compared to people without polymyositis, people with polymyositis had similar odds of hospital charges above the median, hospital stay > 3 days, and discharge to non-home setting post-TKA and post-THA. Polymyositis was associated with significantly lower odds ratio (OR; 95% confidence interval [CI]) of revision and mortality post-THA, 0.44 (0.36, 0.55) and 0.63 (0.48, 0.84), but not post-TKA, 2.98 (0.47, 18.95) and 4.40 (0.61, 31.64), respectively. Findings from the main analyses were confirmed in the sensitivity analyses. People with polymyositis had no increase in healthcare utilization post-TKA/THA. A lower revision rate and mortality post-THA in people with polymyositis need further confirmation. Study findings should reassure the key stakeholders about the benefits of TKA/THA, including people with polymyositis.

Association of Race/Ethnicity With Hospital Discharge Disposition After Elective Total Knee Arthroplasty

IMPORTANCE

Total knee arthroplasty (TKA) is one of the most common elective procedures performed in adults with end-stage arthritis. Racial disparities in TKA outcomes have been described in the literature.

OBJECTIVES

To assess the association of race/ethnicity with discharge disposition and hospital readmission after elective primary TKA and to assess the association of nonhome discharge disposition with hospital readmission risk.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from the Pennsylvania Health Care Cost Containment Council Database, a large regional database that included demographic data from all discharges of patients who underwent elective primary TKA in 170 nongovernmental acute care hospitals in Pennsylvania from April 1, 2012, to September 30, 2015. Data analyses were conducted from September 29, 2017, to November 29, 2017.

EXPOSURES

Patient race/ethnicity and discharge disposition.

MAIN OUTCOMES AND MEASURES

Discharge disposition and 90-day hospital readmission.

RESULTS

Among 107 768 patients, 7287 (6.8%) were African American, 68 372 (63.4%) were women, 46 420 (43.1%) were younger than 65 years, and 60 636 (56.3%) were insured by Medicare. In multivariable logistic regression, among patients younger than 65 years, African American patients were more likely than white patients to be discharged to inpatient rehabilitation facility (IRF) (adjusted relative risk ratio [aRRR], 2.49 [95% CI, 1.42-4.36]; P = .001) or a skilled nursing facility (SNF) (aRRR, 3.91 [95% CI, 2.17-7.06]; P < .001) and had higher odds of 90-day hospital readmission (adjusted odds ratio [aOR], 1.30 [95% CI, 1.02-1.67]; P = .04). Compared with white patients 65 years or older, African American patients 65 years or older were more likely to be discharged to SNF (aRRR, 3.30 [95% CI, 1.81-6.02]; P < .001). In both age groups, discharge to an IRF (age <65 years: aOR, 3.62 [95% CI, 2.33-5.64]; P < .001; age ≥65 years: aOR, 2.85 [95% CI, 2.25-3.61]; P < .001) or SNF (age <65 years: aOR, 1.91 [95% CI, 1.37-2.65]; P < .001; age ≥65 years: aOR, 1.55 [95% CI, 1.27-1.89]; P < .001) was associated with higher odds of 90-day readmission.

CONCLUSIONS AND RELEVANCE

This cohort study found that race/ethnicity was associated with higher odds of discharge to an IRF or SNF for postoperative care after primary TKA. Among patients younger than 65 years, African American patients were more likely than white patients to be readmitted to the hospital within 90 days. Discharge to an IRF or SNF for postoperative care and rehabilitation was also associated with a higher risk of readmission to an acute care hospital.

Percutaneous Peripheral Nerve Stimulation to Control Postoperative Pain, Decrease Opioid Use, and Accelerate Functional Recovery Following Orthopedic Trauma

Orthopedic trauma is a significant military problem, causing several of the most disabling conditions with high rates of separation from duty and erosion of military readiness. The objective of this report is to summarize the findings of case series of a non-opioid therapy-percutaneous peripheral nerve stimulation (PNS) - and describe its potential for postoperative analgesia, early opioid cessation, and improved function following orthopedic trauma. Percutaneous PNS has been evaluated for the treatment of multiple types of pain, including two case series on postoperative pain following total knee replacement (n = 10 and 8, respectively) and a case series on postamputation pain (n = 9). The orthopedic trauma induced during TKR is highly representative of multiple types of orthopedic trauma sustained by Service members and frequently produces intense, prolonged postoperative pain and extended opioid use following surgery. Collectively, the results of these three clinical studies demonstrated that percutaneous PNS can provide substantial pain relief, reduce opioid use, and improve function. These outcomes suggest that there is substantial potential for the use of percutaneous PNS following orthopedic trauma.

Exploring the clinical context of adopting an instrumented insole: a qualitative study of clinicians' preferences in England

OBJECTIVES

This study explores clinicians' views of the clinical uptake of a smart pressure-sensing insole, named Flexifoot, to enhance the care and management of patients with osteoarthritis (OA). Clinicians are key users of wearable technologies, and can provide appropriate feedback for a specific device for successful clinical implementation.

DESIGN

Qualitative study with in-depth, semi-structured interviews, analysed using inductive analysis to generate key themes.

SETTING

Conducted in a University setting.

PARTICIPANTS

30 clinicians were interviewed (11 physiotherapists, 11 orthopaedic surgeons, 5 general practitioners, 3 podiatrists).

RESULTS

All clinicians regarded Flexifoot to be useful for the care and management of patients in adjunction to current methods. Responses revealed four main themes: use, data presentation, barriers to use and future development. Flexifoot data were recognised as capable of enhancing information exchange between clinicians and patients, and also between clinicians themselves. Participants supported the use of feedback for rehabilitation, screening and evaluation of treatment progress/success purposes. Flexifoot use by patients was encouraged as a self-management tool that may motivate them by setting attainment goals. The data interface should be secure, concise and visually appealing. The measured parameters of Flexifoot, its duration of wear and frequency of data output would all depend on the rationale for its use. The clinicians and patients must collaborate to optimise the use of Flexifoot for long-term monitoring of disease for patient care in clinical practice. Many identified potential other uses for Flexifoot.

CONCLUSIONS

Clinicians thought that Flexifoot may complement and improve current methods of long-term patient management for OA or other conditions in clinical settings. Flexifoot was recognised to be useful for objective measures and should be tailored carefully for each person and condition to maximise compliance. Adopting the device, and other similar technologies, requires reducing the main barriers to use (time, cost, patient compliance) before its successful implementation.

Medially-stabilized total knee arthroplasty does not alter knee laxity and balance in cadaveric knees

Instability after total knee arthroplasty (TKA) can lead to suboptimal outcomes and revision surgery. Medially-stabilized implants aim to more closely replicate normal knee motion than other implants following TKA, but no study has investigated knee laxity (motion under applied loads) and balance (i.e., difference in varus/valgus motion under load) following medially-stabilized TKA. The primary purposes of this study were to investigate how medially-stabilized implants change knee laxity in non-arthritic, cadaveric knees, and if it produces a balanced knee after TKA. Force-displacement data were collected on 18 non-arthritic cadaveric knees before and after arthroplasty using medially-stabilized implants. Varus-valgus and anterior-posterior laxity and varus-valgus balance were compared between native and medially-stabilized knees at 0°, 20°, 60°, and 90° under three different loading conditions. Varus-valgus and anterior-posterior laxities were not different between native and medially-stabilized knees under most testing conditions (p ≥ 0.068), but differences of approximately 2° less varus-valgus laxity at 20° of flexion and 4 mm more anterior-posterior laxity at 90° were present from native laxities (p < 0.017) Medially-stabilized implant balance had ≤1.5° varus bias at all flexion angles. Future studies should confirm if the consistent laxity afforded by the medially-stabilized implant is associated with better and more predictable postoperative outcomes. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:335-349, 2019.

Preoperative quadriceps weakness preferentially predicts postoperative aberrant movement patterns during high-demand mobility following total knee arthroplasty

BACKGROUND

Nearly all patients with total knee arthroplasty show aberrant movement patterns during tasks requiring greater joint demand compared to matched peers. Greater movement compensation leads to increased loading onto other joints, decreased functional capacity and limited reserve for independence later in life. Understanding how preoperative predictors contribute to postoperative aberrant movement patterns is needed to make better decisions for patients considering total knee arthroplasty.

METHODS

Forty-seven patients were tested preoperatively and six months following primary total knee arthroplasty. Demographic (age, sex, body mass), self-reported (knee pain, perception of physical performance, physical activity level), physical performance (quadriceps strength, lower limb power and timed stair climbing) and surgical metrics were collected as predictor variables. Three-dimensional models based on joint mechanic asymmetry during a decline walking task were collected at six months postoperatively. Decline walking is a preferred means to assess the surgical knee's contribution to limb performance during high-demand tasks. Bootstrap inclusion fraction was employed to compare the stability of each predictor variable prior to the final regression model.

RESULTS

Preoperative quadriceps strength (β = 0.33; p = 0.04) showed a significant relationship with knee extensor angular impulse during loading phase. No other predictor variable had any meaningful relationship with aberrant movement patterns (p > 0.05).

CONCLUSION

Our findings highlight patients' preoperative quadriceps strength as a meaningful predictor of postoperative performance. Preoperative quadriceps strength should be addressed when considering the knee's ability to contribute to higher demanding mobility tasks following surgery.

The EKSPECT study: the influence of Expectation modification in Knee arthroplasty on Satisfaction of PatiEnts: study protocol for a randomized Controlled Trial

Background

One out of five patients is unsatisfied to some extent after total knee arthroplasty (TKA). Unmet expectations are the main driver of post-operative dissatisfaction. Improved pre-operative education on realistic expectations for long-term outcome after TKA potentially leads to higher post-operative satisfaction. The effect of expectation modification on post-operative satisfaction in TKA patients has not yet been studied. The primary objective of the presented study is to examine whether an educational module on long-term recovery after TKA will improve patient satisfaction compared to usual pre-operative education.

Methods

The EKSPECT study is a randomized controlled trial. Patients with symptomatic and radiographic knee osteoarthritis who are indicated for a primary TKA will be randomized to the usual pre-operative education (control group) or usual education plus an additional module on realistic expectations for long-term recovery (intervention group). Patients will be naïve to study objective and difference between study groups. Outcome expectations will be measured blinded for group allocation using the HSS Knee Replacement Expectations Survey at baseline (before the intervention), pre-operatively (after the intervention) and fulfillment of expectations at 12-month follow-up. Baseline physical function, quality of life and psychological factors are measured using self-reported questionnaires. The primary outcome measure is satisfaction with treatment result at the 12-month follow-up.

Discussion

The EKSPECT study should provide evidence on the effectiveness of an education module on long-term recovery after TKA to improve treatment satisfaction. If beneficial, the education module is a simple intervention with a low burden for patients, which can easily be implemented in clinical practice.

Trial registration

Dutch Trial Registry registration number: NTR5779. Registered on 17 March 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2821-2) contains supplementary material, which is available to authorized users.

The Effect of Comorbidities and Age on Functional Outcomes After Total Knee Arthroplasty in the Octogenarian: A Matched Cohort Study

Introduction:

According to the World Health Organization data repository, the average life expectancy at birth for Singapore in 2015 has risen to 83.4 years, and many octogenarians (OG) remain active socioeconomically. The aim of this study is to compare the improvement and the impact of comorbidities on functional recovery after total knee arthroplasty (TKA) between OG and their younger counterparts.

Methods:

This is a retrospective study of prospectively collected data from a single institution arthroplasty register. Between January 2006 and December 2011, 209 OG with primary knee osteoarthritis underwent TKA. Each OG (mean age 82 ± 2.1) was then carefully matched to a younger control group (YG, mean age 66 ± 4.5). Their postoperative outcomes measured include Oxford Knee Score (OKS), SF36-Physical Function (SF-PF), and knee society rating score comprising of Knee Score (KS) and Function Score (FS). Their respective degrees of improvement were compared and adjusted for their baseline comorbidities, measured using the Deyo-Charlson Comorbidity Index (D-CCI).

Results:

There were more comorbidities among the OG (P < .05). Both groups saw the largest improvement (P < .05) during the first 6 months. There was no statistical significance between their improvement for OKS, KS, and FS between baseline and 6 months and OKS, FS, and SF-PF between 6 and 24 months. Adjusted for D-CCI using linear regression, the above results remained largely unchanged.

Discussion:

In our study, both groups showed significant improvement across all functional outcomes, especially during the first 6 months. The improvement observed in OG at 6 and 24 months was comparable to that of YG, despite an overall higher baseline D-CCI.

Conclusions:

Total knee arthroplasty is a viable treatment option for the OG, offering good functional outcomes and results at 6 and 24 months when compared to their younger counterparts.

Insurance Status Affects In-Hospital Complication Rates After Total Knee Arthroplasty

Insurance status has been shown to be a predictor of patient morbidity and mortality. The purpose of this study was to evaluate the effect of patient insurance status on the in-hospital complication rates following total knee arthroplasty. Data were obtained from the Nationwide Inpatient Sample (2004 through 2011). Patient demographics and comorbidities were analyzed and stratified by insurance type. Analysis was performed with a matched cohort comparing complication rates between patients with Medicare vs private insurance using the coarsened exact matching algorithm and multivariable logistic regression. A total of 1,352,505 patients (Medicare, 57.8%; private insurance, 35.6%; Medicaid/uninsured, 3.1%; other, 3.3%; unknown, 0.2%) fulfilled the inclusion criteria. The matched cohort analysis comparing Medicare with privately insured patients showed significantly higher risk of mortality (relative risk [RR], 1.34; P<.001), wound dehiscence (RR, 1.32; P<.001), central nervous system complications (RR, 1.16; P=.030), and gastrointestinal complications (RR, 1.13; P<.001) in Medicare patients, whereas privately insured patients had a higher risk of cardiac complications (RR, 0.93; P=.003). Independent of insurance status, older patients and patients with an increased comorbidity index were also associated with a higher complication rate and mortality following total knee arthroplasty. These data suggest that insurance status may be considered as an independent risk factor for increased complications when stratifying patients preoperatively for total knee replacement. Further research is needed to investigate the disparities in these findings to optimize patient outcomes following total knee arthroplasty. [Orthopedics. 2018; 41(3):e340-e347.].

Post-Acute Rehabilitation After Total Knee Replacement: A Multicenter Randomized Clinical Trial Comparing Long-Term Outcomes

OBJECTIVE

To evaluate the long-term benefit of providing a post-acute, outpatient group exercise program for patients following primary total knee replacement (TKR) surgery for osteoarthritis.

METHODS

A multicenter randomized clinical trial was conducted in 12 Australian public and private hospital centers. A total of 422 participants, ages 45-75 years, were randomly allocated prior to hospital discharge to the post-acute group exercise program or to usual care and were assessed at 6 weeks, 6 months, and 12 months after surgery. The main outcomes were operated knee pain and activity limitations at 12 months using the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. Secondary outcomes included health-related quality of life (Short Form 12 health survey), knee extension and flexion strength, stair-climb power, 50-foot walk speed, and active knee range of motion.

RESULTS

While both allocation groups achieved significant improvements in knee pain and activity limitations over the 12-month followup period, there were no significant differences in these main outcomes, or in the secondary physical performance measures, between the 2 treatment allocations. Twelve months after TKR, 69% and 72% of participants allocated to post-acute exercise and usual acute care, respectively, were considered to be treatment-responders. While population normative values for self-report measures of pain, activity limitation, and health-related quality of life were attained 12 months after TKR, marked deficits in physical performance measures remained.

CONCLUSION

Providing access to a post-acute group exercise program did not result in greater reductions in long-term knee pain or activity limitations than usual care. Patients undergoing primary TKR retain marked physical performance deficits 12 months after surgery.

Unexplained Pain Post Total Knee Arthroplasty With an Oxford Knee Score ≥20 at 6 Months Predicts Good 2-Year Outcome

BACKGROUND

Total knee arthroplasty (TKA) is an effective procedure for end-stage osteoarthritis of the knee. Some patients experience persistent unexplained pain post-TKA despite normal investigations. The purpose of this study is to identify which of these patients are likely to improve without any surgical intervention. We hypothesize that patients with unexplained persistent pain and a poor 6-month Oxford knee score (OKS) post-TKA can improve at 2 years.

METHODS

Prospectively collected data for all primary unilateral TKA performed from June 2004 to January 2012 were analyzed to identify which patients with unexplained pain at 6 months will improve at 2 years. Patients were included if they had persistent pain and an OKS <27 at 6 months; normal radiological and clinical investigations; no infection identified; surgery performed for primary osteoarthritis. Two hundred sixty patients with OKS <27 at 6 months were analyzed. These patients were subdivided into 2 groups (group 1: 6-month OKS 20-26, group 2: 6-month OKS less than 20).

RESULTS

One hundred ninety-one out of 208 (92%) patients in group 1 experienced improvement in pain and outcome at 2 years. Most of the group 1 patients attained a minimal clinically important difference in OKS of at least 5 (P < .001) at 2 years. Group 1 patients also reported better Knee Society Functional Score and Short Form Survey 36 mean scores at 2 years.

CONCLUSION

In patients with unexplained pain, an OKS of at least 20 at 6 months predicts good functional outcome at 2 years.

Preoperative Risk Factors for, and Incidence of Delayed Surgery in Elective Primary Total Knee Arthroplasty After Hospital Admission: The ACS-NSQIP

BACKGROUND

Approximately 600,000 total knee arthroplasties (TKA) are performed every year in the United States and the number of procedures has increased substantially every year. These demands may further strain the government, insurers, and patients struggling with increasing healthcare spending. A delay in proceeding to surgery after hospital admission may affect the overall healthcare costs. To our knowledge, the current literature has not addressed the incidence of, and preoperative risk factors for, a surgical delay in TKA.

METHODS

The ACS-NSQIP 2011 database was reviewed to identify patients undergoing elective primary total knee arthroplasty (TKA) using the Current Procedural Terminology (CPT) code 27447. 14,881 cases were no delay in proceeding to surgery after hospital admission while 139 cases were delayed for TKA. Risk factors or comorbidities contributing to surgical delay in TKA were identified. A univariate analysis of all patient parameters was conducted to measure the difference between the two cohorts. Finally, a multivariate logistic regression analysis was then conducted to identify risk factors or comorbidities for surgical delay.

RESULTS

There were 139 cases of surgical delay in TKA (0.93%). Congestive heart failure (P = 0.017), bleeding disorder (P <0.0001), sepsis (P <0.0001), a prior operation in the past 30 days (P <0.0001), dependent functional status (P <0.0001), ASA class 3 (P = 0.046), and hematocrit <38% (P <0.0001) were independent risk factors for a surgical delay. Postoperative medical complication (2.2% vs 0.8%, P < 0.0001) in surgical delay was significantly higher than non-delayed cohort.

CONCLUSION

The optimization of preoperative modifiable risk factors appears to be one of the best strategies to reduce delayed surgery and therefore costs in TKA.

Preoperative Determinants of Patient-reported Pain and Physical Function Levels Following Total Knee Arthroplasty: A Systematic Review

BACKGROUND

A sound knowledge of the determinants of total knee arthroplasty (TKA) outcomes could help in patient selection, preparation and education. We aimed to assess the current status of the literature evaluating preoperative determinants of early and medium term patient-reported pain and disability following TKA.

METHOD

A search in Medline, Pubmed, Embase and CINAHL until October 2014 was undertaken. Selection criteria included: 1- participants undergoing primary unilateral TKA with a follow-up from 6 months to 2 years, 2- validated disease-specific patient-reported outcome measures assessing pain and/or function used as outcome measure and 3- identification of preoperative determinants obtained via multivariate analyses. Risk of bias was assessed using a modified version of the Methodology checklist for prognostic studies.

RESULTS

Thirty-three prognostic explanatory studies were included. Mean total score of the methodological quality was 80.7±12.2 %. Sociodemographic and psychosocial determinants included greater socioeconomic deprivation (both studies), greater levels of depression and/or anxiety (7 out of 10 studies) and greater preoperative pain catastrophizing (all 3 studies). Significant clinical determinants included worse pre-operative knee related pain or disability (20 out of 22 studies), presence or greater levels of comorbidity (12 out of 23 studies), back pain (4 out of 5 studies) and lower general health (all 11 studies).

CONCLUSION

Several significant determinants of short to medium-term pain and functional outcomes following TKA have been summarized by studies with moderate-to-high methodological quality. No conclusions can be reached regarding the strength of the associations between significant determinants and TKA results because of heterogeneity of study methodologies and results. Further high-quality research is required.

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.

Development of a Prediction Model to Estimate the Risk of Walking Limitations in Patients with Total Knee Arthroplasty

Objective.

Early and accurate risk prediction of walking limitations after total knee arthroplasty (TKA) is important for clinical and economic reasons. However, to our knowledge, no studies have systematically integrated multiple predictors into a single, clinically practical model. Our study aimed to develop a prediction model to estimate the risk of post-TKA walking limitations.

Methods.

We performed a prospective cohort study of 1096 patients who underwent elective, primary TKA between July 2013 and September 2014. Candidate predictors included patient demographics, surgical factors, and pre- and early (1-mo) post-TKA functional measures. The outcome of interest was self-reported walking limitations at 6 months of post-TKA. We used multivariable proportional odds regression with bootstrap internal validation to develop the model.

Results.

In all, 12% of patients reported walking limitations (maximum walk time ≤ 15 min) at 6 months postsurgery. The main predictors of increasing levels of walking limitations were preoperative walking limitations (overall p < 0.001), higher levels of body mass index [interquartile range (IQR)-OR 1.3, 95% CI 1.2–1.5], lower values of 1-month post-TKA gait speed (IQR-OR 1.9, 95% CI 1.3–2.6), the presence of contralateral knee pain (OR 1.9, 95% CI 1.2–3.0), and the use of a quadstick preoperatively (OR 3.5, 95% CI 1.7–7.3). The prediction model had an optimism-corrected concordance index of 0.71.

Conclusion.

A small but sizable proportion of patients with TKA had persistent mobility limitations. Our prediction model may help to risk-stratify patients, and external validation is required before the model can be used in clinical practice.

Latent Class Growth Analysis predicts long term pain and function trajectories in total knee arthroplasty: a study of 689 patients

OBJECTIVE

To characterize groups of subjects according to their trajectory of knee pain and function over 1 to 5 years post total knee arthroplasty (TKA).

METHODS

Patients from one centre who underwent primary TKA (N = 689) between 2006 and 2008. The Knee Society Score (KSS) was collected pre-operatively and annually post-operatively. Latent Class Growth Analysis (LCGA) was used to classify groups of subjects according to their trajectory of knee pain and function over 1-5 years post-surgery.

RESULTS

LCGA identified a class of patients with persistent moderate knee pain (22.0%). Predictors (OR, 95% CI) of moderate pain trajectory class membership were pre-surgery SF12 mental component summary (MCS) per 10 points (0.65, 0.54-0.79) and physical component summary (PCS) per 10 points (0.50, 0.33-0.76), Charlson Comorbidity Index (CCI) one (1.70, 1.07-2.69) and ≥two (2.82, 1.59-4.81) and the absence of computer-navigation (2.26, 1.09-4.68). LCGA also identified a class of patients with poor function (23.0%). Predictors of low function trajectory class membership were, female sex (3.31, 1.95-5.63), advancing age per 10 years (2.27, 1.69-3.02), pre-surgery PCS per 10 points (0.50, 0.33-0.74), obesity (1.69, 1.05-2.72), morbid obesity (3.12, 1.55-6.27) and CCI ≥two (2.50, 1.41-4.42).

CONCLUSIONS

Modifiable predictors of poor response to TKA included baseline co-morbidity, physical and mental well-being and obesity. This provides useful information for clinicians in terms of informing patients of the expected course of longer term outcomes of TKA and for developing prediction algorithms that identify patients in whom there is a high likelihood of poor surgical response.

Male and female differences in musculoskeletal disease

Gender differences exist in the presentation of musculoskeletal disease, and recognition of the differences between men and women's burden of disease and response to treatment is key in optimizing care of orthopaedic patients. The role of structural anatomy differences, hormones, and genetics are factors to consider in the analysis of differential injury and arthritic patterns between genders.

Are outcomes after total knee arthroplasty worsening over time? A time-trends study of activity limitation and pain outcomes

Background

To examine whether function and pain outcomes of patients undergoing primary total knee arthroplasty (TKA) are changing over time.

Methods

The Mayo Clinic Total Joint Registry provided data for time-trends in preoperative and 2-year post-operative activity limitation and pain in primary TKA patients from 1993-2005. We used chi-square test and analysis for variance, as appropriate. Multivariable-adjusted analyses were done using logistic regression.

Results

In a cohort of 7,229 patients who underwent primary TKA during 1993-2005, mean age was 68.4 years (standard deviation (SD), 9.8), mean BMI was 31.1 (SD, 6.0) and 55% were women. Crude estimates showed that preoperative moderate-severe overall limitation were seen in 7.3% fewer patients and preoperative moderate-severe pain in 2.7% more patients in 2002-05, compared to 1992-95 (p < 0.001 for both). At 2-years, crude estimates indicated that compared to 1992-95, moderate-severe post-TKA overall limitation was seen in 4.7% more patients and moderate-severe post-TKA pain in 3.6% more patients in 2002-05, both statistically significant (p ≤ 0.018) and clinically meaningful. In multivariable-adjusted analyses that adjusted for age, sex, anxiety, depression, Deyo-Charlson index, body mass index and preoperative pain/limitation, patients had worse outcomes 2-year post-TKA in 2002-2005 compared to 1993-95 with an odds ratio (95% confidence interval (CI); p-value) of 1.34 (95% CI: 1.02, 1.76, p = 0.037) for moderate-severe activity limitation and 1.79 (95% CI: 1.17, 2.75, p = 0.007) for moderate-severe pain.

Conclusion

Patient-reported function and pain outcomes after primary TKA have worsened over the study period 1993-95 to 2002-05. This time-trend is independent of changes in preoperative pain/limitation and certain patient characteristics.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-440) contains supplementary material, which is available to authorized users.

Patient-related predictors of treatment failure after primary total knee arthroplasty for osteoarthritis

The aim was to identify patient-related predictors of treatment failure after primary total knee arthroplasty for osteoarthritis. Treatment failure included surgical revision or clinical failure, which was defined by less than 70 in any score of the Knee Society. Prospective follow-up was performed in 412 consecutive patients with a minimum of 5 years. Multivariate logistic regression analysis revealed that higher Charlson index, worse preoperative Knee Society function, and Western Ontario McMaster University pain component were significantly associated with treatment failure. This study identified clinically important patient-related predictors of treatment failure after TKA, which may be useful preoperatively in identifying patients with risk of failure.

Prediction of poor outcomes six months following total knee arthroplasty in patients awaiting surgery

Background

Identification of patients experiencing poor outcomes following total knee arthroplasty (TKA) before the intervention could allow better case selection, patient preparation and, likely, improved outcomes. The objective was to develop a preliminary prediction rule (PR) to identify patients enrolled on surgical wait lists who are at the greatest risk of poor outcomes 6 months after TKA.

Methods

141 patients scheduled for TKA were recruited prospectively from the wait lists of 3 hospitals in Quebec City, Canada. Knee pain, stiffness and function were measured 6 months after TKA with the Western Ontario and McMaster Osteoarthritis Index (WOMAC) and participants in the lowest quintile for the WOMAC total score were considered to have a poor outcome. Several variables measured at enrolment on the wait lists (baseline) were considered potential predictors: demographic, socioeconomic, psychosocial, and clinical factors including pain, stiffness and functional status measured with the WOMAC. The prediction rule was built with recursive partitioning.

Results

The best prediction was provided by 5 items of the baseline WOMAC. The rule had a sensitivity of 82.1% (95% CI: 66.7-95.8), a specificity of 71.7% (95% CI: 62.8-79.8), a positive predictive value of 41.8% (95% CI: 29.7-55.0), a negative predictive value of 94.2% (95% CI: 87.1-97.5) and positive and negative likelihood ratios of 2.9 (95% CI: 1.8-4.7) and 0.3 (95% CI: 0.1-0.6) respectively.

Conclusions

The developed PR is a promising tool to identify patients at risk of worse outcomes 6 months after TKA as it could help improve the management of these patients. Further validation of this rule is however warranted before clinical use.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-299) contains supplementary material, which is available to authorized users.