Should We Aim to Help Patients “Feel Better” or “Feel Good” After Total Hip Arthroplasty? Determining Factors Affecting the Achievement of the Minimal Clinically Important Difference and Patient Acceptable Symptom State

BackgroundRecent attempts have been made to use preoperative patient-reported outcome measure (PROM) thresholds as prior authorization criteria based on the assumption that patients who have higher baseline scores are less likely to achieve the minimal clinically important difference (MCID). This study aimed to identify factors affecting the achievement of MCID and patient acceptable symptom state (PASS) after total hip arthroplasty (THA), and to determine the overlap between the two outcomes.MethodsWe identified 3,581 primary, unilateral THAs performed at a single practice in 2015-2019. PROMs including Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR) and 12-item Short Form Health Survey were collected preoperatively and 1-year postoperatively. The likelihood of attaining PASS according to attainment of MCID was assessed. Multivariable regression was used to identify independent predictors of MCID and PASS.ResultsIn total, 79.8% achieved MCID and 73.6% achieved PASS for HOOS-JR. Approximately 1 in 7 patients who achieved MCID did not eventually achieve PASS. Worse preoperative HOOS-JR (odd ratio 0.933) was associated with MCID attainment. Better preoperative HOOS-JR (odd ratio 1.015) was associated with PASS attainment. Men, lower body mass index, better American Society of Anesthesiologists score, and better preoperative 12-item Short Form Health Survey mental score were predictors of MCID and PASS. Age, race, ethnicity, Charlson Comorbidity Index, and smoking status were not significant predictors.ConclusionPreoperative PROMs were associated with achieving MCID and PASS after THA, albeit in opposite directions. Clinicians should strive to help patients “feel better” and “feel good” after surgery. Preoperative PROMs should not solely be used to prioritize access to care.     

Are Oxford Hip Score and Western Ontario and McMaster Universities Osteoarthritis Index Useful Predictors of Clinical Meaningful Improvement and Satisfaction After Total Hip Arthroplasty?

BackgroundUp to 15% of patients express dissatisfaction after total hip arthroplasty (THA). Preoperative patient-report outcome measures (PROMs) scores can potentially mitigate this by predicting postoperative satisfaction, identifying patients that will benefit most from surgery. The aim of this study was to (1) calculate the minimal clinically important difference (MCID) thresholds for Oxford Hip Score (OHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Short Form-36 (SF-36) mental component summary (MCS) and physical component summary (PCS) scores and (2) identify the threshold values of these PROMs that could be used to predict patient satisfaction and expectation fulfilment.MethodsProspectively collected registry data of 1334 primary THA patients who returned for 2-year follow-up from 1998 to 2016 were reviewed. All patients were assessed preoperatively and postoperatively at 2 years using the OHS, WOMAC, and SF-36 PCS/MCS scores. The MCID for each PROMs was calculated, and the proportion of patients that attained MCID was recorded. The relationship between satisfaction, expectation fulfilment, and MCID attainment was analyzed using Spearman rank correlation. Optimal threshold scores for each PROM that predicted MCID attainment and satisfaction/expectation fulfilment at 2 years were calculated using receiver operating curve analysis.ResultsThe calculated MCID for OHS, WOMAC, SF-36 PCS, and SF-36 MCS were 5.2, 10.8, 6.7, and 6.2, respectively. A threshold value of 24.5 for the preoperative OHS was predictive of achieving WOMAC MCID at 2 years after THA (area under the curve 0.80, P < .001). 93.1% of patients were satisfied, and 95.5% had expectations fulfilled at 2 years. None of the PROMs were able to predict satisfaction.ConclusionOHS and WOMAC scores can be used to determine clinical meaningful improvement but are limited in their ability to predict patient satisfaction after THA.     

Metrics of Clinically Important Changes in Total Hip Arthroplasty: A Systematic Review

BackgroundAlthough patient-reported outcome measures (PROMs) have become a regularly used metric, there is little consensus on the methodology used to determine clinically relevant postoperative outcomes. We systematically reviewed the literature for studies that have identified metrics of clinical efficacy after total hip arthroplasty (THA) including minimal clinically important difference (MCID), patient acceptable symptom state (PASS), minimal detectable change (MDC), and substantial clinical benefit (SCB).MethodsA systematic review examining quantitative metrics for assessing clinical improvement with PROMs following THA was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the MEDLINE database from 2008 to 2020. Inclusion criteria included full texts, English language, primary THA with minimum 1-year follow-up, use of metrics for assessing clinical outcomes with PROMs, and primary derivations of those metrics. Sixteen studies (24,487 THA patients) met inclusion criteria and 11 different PROMs were reported.ResultsMCIDs were calculated using distribution methods in 7 studies (44%), anchor methods in 2 studies (13%), and both methods in 2 studies (13%). MDC was calculated in 2 studies, PASS was reported in 1 study using anchor-based method, and SCB was calculated in 1 study using anchor-based method.ConclusionThere is a lack of consistency in the literature regarding the use and interpretation of PROMs to assess patient satisfaction. MCID was the most frequently reported measure, while MDC, SCB, and PASS were used relatively infrequently. Method of derivation varied based on the PROM used; distribution method was more frequently used for MCID.     

Determining minimal clinically important difference estimates following surgery for degenerative conditions of the lumbar spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) registry

BACKGROUND CONTEXTThere is significant variability in minimal clinically important difference (MCID) criteria for lumbar spine surgery that suggests population and primary pathology specific thresholds may be required to help determine surgical success when using patient reported outcome measures (PROMs).PURPOSEThe purpose of this study was to estimate MCID thresholds for 3 commonly used PROMs after surgical intervention for each of 4 common lumbar spine pathologies.STUDY DESIGN/SETTINGObservational longitudinal study of patients from the Canadian Spine Outcomes and Research Network (CSORN) national registry.PATIENT SAMPLEPatients undergoing surgery from 2015 to 2018 for lumbar spinal stenosis (LSS; n = 856), degenerative spondylolisthesis (DS; n = 591), disc herniation (DH; n = 520) or degenerative disc disease (DDD n = 185) were included.OUTCOME MEASURESPROMs were collected presurgery and 1-year postsurgery: the Oswestry Disability Index (ODI), and back and leg Numeric Pain Rating Scales (NPRS). At 1-year, patients reported whether they were ‘Much better’/’Better’/’Same’/’Worse’/’Much worse’ compared to before their surgery. Responses to this item were used as the anchor in analyses to determine surgical MCIDs for benefit (‘Much better’/‘Better’) and substantial benefit (‘Much better’).METHODSMCIDs for absolute and percentage change for each of the 3 PROMs were estimated using a receiving operating curve (ROC) approach, with maximization of Youden's index as primary criterion. Area under the curve (AUC) estimates, sensitivity, specificity and correct classification rates were determined. All analyses were conducted separately by pathology group.RESULTSMCIDs for ODI change ranged from −10.0 (DDD) to −16.9 (DH) for benefit, and −13.8 (LSS) to −22.0 (DS,DH) for substantial benefit. MCID for back and leg NPRS change were −2 to −3 for each group for benefit and −4.0 for substantial benefit for all groups on back NPRS. MCID estimates for percentage change varied by PROM and pathology group, ranging from −11.1% (ODI for DDD) to −50.0% (leg NPRS for DH) for benefit and from −40.0% (ODI for DDD) to −66.6% (leg NPRS for DH) for substantial benefit. Correct classification rates for all MCID thresholds ranged from 71% to 89% and were relatively lower for absolute vs percent change for those with high or low presurgical scores.CONCLUSIONSOur findings suggest that the use of generic MCID thresholds across pathologies in lumbar spine surgery is not recommended. For patients with relatively low or high presurgery PROM scores, MCIDs based on percentage change, rather than absolute change, appear generally preferable. These findings have applicability in clinical and research settings, and are important for future surgical prognostic work.     

Reporting Clinical Significance in Hip Arthroscopy: Where Are We Now?

Background

Although p values are standard for reporting statistical significance of patient-reported outcome measures (PROMs), the shift toward clinically important outcome values, including minimal clinically important difference (MCID) and substantial clinical benefit (SCB), necessitates re-evaluation of the current literature.

Questions/Purposes

We sought to answer two questions regarding studies on primary hip arthroscopy performed for the treatment of femoroacetabular impingement syndrome (FAIS). (1) Do such studies reporting statistical significance on common PROMs meet published MCID/SCB thresholds? (2) What proportion of such studies report both statistical and clinical significance?

Methods

We identified four papers published in two journals defining MCID/SCB values on the modified Harris Hip Score (mHHS), Hip Outcome Score–Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sport (HOS-Sport), international Hip Outcome Tool (iHOT-33), and its short version (iHOT-12) for different groups of FAIS patients undergoing hip arthroscopy. We reviewed these two journals from the dates of publication to the present to identify papers reporting changes in post-operative PROMs. The difference in pre- and post-operative scores on each PROM was calculated and compared to MCID/SCB thresholds.

Results

Twelve studies were included. Ten studies (83%) evaluated mHHS (90% met MCID, 50% met SCB), seven (58%) evaluated HOS-ADL (100% met MCID/SCB) and HOS-Sport (100% met MCID, 57% met SCB), and one (8%) evaluated iHOT-33 (met MCID/SCB) and iHOT-12 (met MCID). Most studies met MCID and SCB at both 1- and 2-year timepoints. Of the studies evaluated, 50% reported clinical relevance.

Conclusions

Nearly all studies evaluated met MCID, while fewer met SCB. Only half discussed these clinical measures. It is proposed that all future studies report both statistical and clinical significance as standard best practice.

     

John Charnley Award: Preoperative Patient-reported Outcome Measures Predict Clinically Meaningful Improvement in Function After THA

BackgroundDespite the overall effectiveness of total hip arthroplasty (THA), a subset of patients remain dissatisfied with their results because of persistent pain or functional limitations. It is therefore important to develop predictive tools capable of identifying patients at risk for poor outcomes before surgery.Questions/purposesThe purpose of this study was to use preoperative patient-reported outcome measure (PROM) scores to predict which patients undergoing THA are most likely to experience a clinically meaningful change in functional outcome 1 year after surgery.MethodsA retrospective cohort study design was used to evaluate preoperative and 1-year postoperative SF-12 version 2 (SF12v2) and Hip Disability and Osteoarthritis Outcome Score (HOOS) scores from 537 selected patients who underwent primary unilateral THA. Minimum clinically important differences (MCIDs) were calculated using a distribution-based method. A receiver operating characteristic analysis was used to calculate threshold values, defined as the levels at which substantial changes occurred, and their predictive ability. MCID values for HOOS and SF12v2 physical component summary (PCS) scores were calculated to be 9.1 and 4.6, respectively. We analyzed the effect of SF12v2 mental component summary (MCS) scores, which measure mental and emotional health, on SF12v2 PCS and HOOS threshold values.ResultsThreshold values for preoperative HOOS and PCS scores were a maximum of 51.0 (area under the curve [AUC], 0.74; p < 0.001) and 32.5 (AUC, 0.62; p < 0.001), respectively. As preoperative mental and emotional health improved, which was reflected by a higher MCS score, HOOS and PCS threshold values also increased. When preoperative mental and emotional health were taken into account, both HOOS and PCS threshold values’ predictive ability improved (AUCs increased to 0.77 and 0.69, respectively).ConclusionsWe identified PROM threshold values that predict clinically meaningful improvements in functional outcome after THA. Patients with a higher level of preoperative function, as suggested by HOOS or PCS scores above the defined threshold values, are less likely to obtain meaningful improvement after THA. Lower preoperative mental and emotional health decreases the likelihood of achieving a clinically meaningful improvement in function after THA. The results of this study may be used to facilitate discussion between physicians and patients regarding the expected benefit after THA and to support the development of patient-based informed decision-making tools. For example, despite significant disease, patients with high preoperative function, as measured by PROM scores, may choose to delay surgery given the low likelihood of experiencing a meaningful improvement postoperatively. Similarly, patients with notably low MCS scores might best be counseled to address mental health issues before embarking on surgery.

Level of Evidence

Level III, prognostic study.     

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

BackgroundThe 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.MethodsWe 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.ResultsIn 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.ConclusionPreoperative 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.     

Are Functional Outcomes of a Total Hip Arthroplasty Predictive of a Contralateral Total Hip Arthroplasty: A Retrospective Cohort Study

BackgroundCurrent literature suggests that 8%-35% of patients undergoing total hip arthroplasty (THA) undergo a subsequent contralateral THA. This study aims to determine if functional outcomes after primary THA predict outcomes in the subsequent primary THA of the contralateral side.MethodsA retrospective cohort of patients undergoing staged bilateral primary THA was reviewed. The Oxford Hip Score (OHS) was utilized as the functional outcome measurement tool and was assessed preoperatively and at one year postoperatively. The minimal clinically important difference (MCID) was assessed. Based on the first-side THA one-year outcomes, the odds of maintaining an MCID, or not, for the second-side THA were determined.ResultsThe study cohort consisted of 551 patients and 1102 primary THAs. The average postoperative OHSs were similar after the first and second THA. Patients achieving the MCID with the first-side surgery were 2.6 times (95% confidence interval 1.0 to 6.64, P = .04) more likely to achieve the MCID for the second-side surgery than patients failing to reach the MCID for their first-side surgery. After the first THA, 29 (5.3%) patients failed to reach the predefined MCID for the OHS compared with 54 (9.8%) patients undergoing their second THA (odds ratio: 1.96 [95% confidence interval: 1.23 to 3.1], χ² = 8.14, P = .005).ConclusionsFunctional outcomes after the first THA are predictive of functional outcomes of the second THA. Patients are more likely to achieve a clinically significant improvement after their first THA related to higher preoperative OHSs before the second THA.     

Social Determinants of Health and Patient-Reported Outcomes Following Total Hip and Knee Arthroplasty in Veterans

BackgroundSocial determinants of health (SDOH) are the conditions in which people are born, grow, live, work, and age. They are associated with disparities in outcomes following total joint arthroplasty (TJA). These disparities occur even in equal-access healthcare systems such as the Veterans Health Administration (VHA). Our goal was to determine whether SDOH affect patient-reported outcome measures (PROMs) following TJA in VHA patients.MethodsPatients scheduled to undergo total hip or knee arthroplasty at VHA Hospitals in Minneapolis, MN, Palo Alto, CA, and San Francisco, CA, prospectively completed PROMs before and 1 year after surgery. PROMs included the Hip disability and Osteoarthritis Outcome Score, the Knee injury and Osteoarthritis Outcome Score, and their Joint Replacement subscores. SDOH included race, ethnicity, marital status, education, and employment status. The level of poverty in each patient’s neighborhood was determined. Medical comorbidities were recorded. Univariate and multivariate analyses were performed to determine whether SDOH were significantly associated with PROM improvement after surgery.ResultsOn multivariate analysis, black race was significantly negatively correlated with knee PROM improvement and Hispanic ethnicity was significantly negatively correlated with hip PROM improvement compared to whites. Higher baseline PROM scores and lower age were significantly associated with lower PROM improvement. Significant associations were also found based on education, gender, comorbidities, and neighborhood poverty.ConclusionMinority VHA patients have lower improvement in PROM scores after TJA than white patients. Further research is required to identify the reasons for these disparities and to design interventions to reduce them.     

How Should We Define Clinically Significant Outcome Improvement on the iHOT-12?

Background

There is increased emphasis on efficiently administering patient-reported outcome measures (PROMs). The International Hip Outcome Tool-12 (iHOT-12) is a short-form version of the iHOT-33, and relatively little is known about clinically significant outcomes using the iHOT-12.

Questions/Purposes

The purpose of this study was to define minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) for the iHOT-12 and to identify predictors for achieving these psychometric end points in patients undergoing arthroscopic treatment of femoroacetabular impingement (FAI).

Methods

Data was prospectively collected and retrospectively analyzed as part of an institutional hip preservation repository. One hundred and twenty patients were included; mean age and body mass index (BMI) were 38.7 years and 25.9, respectively. A majority of patients were female (67.5%) and white (81.7%) and participated in recreational sports (79.2%). The iHOT-12 was administered pre-operatively and at 1-year follow-up to patients undergoing primary hip arthroscopy for FAI. The following anchor question was also asked at 1-year follow-up: “Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?” MCID was calculated using a distribution-based method. Receiver-operating characteristic analysis with area under the curve was used to confirm the significance of the PASS threshold.

Results

Mean iHOT-12 scores improved from 35.6 at pre-operative assessment to 70.7 at 1-year follow-up. Patients indicating satisfaction with their outcome improved from 37.5 pre-operatively to 79.0 at 1-year follow-up. MCID value for the iHOT-12 was 13.0. The PASS threshold was 63.0, indicating an excellent predictive value that patients scoring above this threshold were likely to have met an acceptable symptom state. Worker’s compensation patients and those with increased BMI were less likely to achieve PASS; lower pre-operative iHOT-12 score was predictive for achieving MCID, and achieving MCID was predictive for achieving PASS.

Conclusion

This is the first study to define PASS and MCID for the iHOT-12, which measures clinically significant outcome improvement comparably to that of other commonly used hip PROMs. As its use becomes more widespread, the iHOT-12 data-points presented in this study can be used to determine clinically significant improvement of patient-reported outcomes.

     

Outcomes Vary Significantly Using a Tiered Approach to Define Success After Total Knee Arthroplasty

BackgroundPatient-reported outcome measures (PROM) allow assessment of clinical outcomes following primary total knee arthroplasty (TKA). The purpose of this study is to use progressively more stringent definitions of success to examine clinical outcomes of primary TKA at 1 year postoperatively and to determine which demographic variables were associated with achieving clinical success.MethodsThe American Joint Replacement Registry was queried from 2012 to 2020 for primary TKA. Patients who completed the following PROMs preoperatively and 1 year postoperatively were included: Western Ontario and McMaster Universities Arthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and KOOS for Joint Replacement (KOOS JR). Mean PROM scores were determined for each visit and between-visit changes were evaluated using paired t-tests. Rates of achievement of minimal clinically important difference (MCID) by distribution-based and anchor-based criteria, Patient Acceptable Symptom State, and substantial clinical benefit were calculated. Logistic regression was used to evaluate the association between demographic variables and odds of clinical success.ResultsIn total, 12,341 TKAs were included. Mean improvement in PROM scores were as follows: KOOS JR, 29; WOMAC-Pain, 33; and WOMAC-Function, 31 (P < .0001 for all). Rates of achievement of each metric were the following: distribution-based MCID, 84%-87%; anchor-based MCID, 46%-79%; Patient Acceptable Symptom State, 54%-82%; and substantial clinical benefit, 68%-81%. Patient age and gender were the most influential demographic factors on achievement of clinical success.ConclusionClinical outcomes at 1 year following TKA vary significantly when using a tiered approach to define success. A tiered approach to interpretation of PROMs should be considered for future research and clinical assessment.     

Age-Related Decline in Patient-Reported Outcomes 2 and 5 Years Following Total Hip Arthroplasty

BackgroundPatient-reported outcome measures (PROMs) help assess therapeutic effectiveness. This study assessed the effect of advanced age on the Hip Disability and Osteoarthritis Outcome Score (HOOS) and Lower Extremity Activity Scale (LEAS) after total hip arthroplasty (THA).MethodsA prospective cohort of patients underwent primary THA at our institution between May 2007 and December 2011. Exposure was age at the time of surgery and outcomes were HOOS and LEAS scores 2 and 5 years postsurgery. We used a multivariable longitudinal generalized estimating equation to elucidate the effect of age on PROM scores.ResultsOur analysis of 3700 THA patients (mean age, 66 years; 56.4% female) demonstrated a decline in scores by age for the LEAS, HOOS Activities of Daily Living, and HOOS Sport and Recreation domains. There was also association between age and HOOS Symptoms and HOOS Quality of Life domains, but not between age and the HOOS Pain domain. Critical ages at which the relationship between age and outcome changed was 63 years for the HOOS Pain, Symptom, Activities of Daily Living, and Quality of Life domains, and 72 years for the HOOS Sport and Recreation domain and the LEAS.ConclusionPatients undergoing THA at older ages reported lower activity and sports and recreation scores than younger patients, but similar pain, symptoms, and quality of life scores. This knowledge can help physicians guide patients’ expectations before THA. Our findings also indicate that PROM scores should be age adjusted when used for quality or value comparisons between hospitals or physicians.     

Improvement in Sleep Patterns After Hip and Knee Arthroplasty: A Prospective Study in 780 Patients

BackgroundThis study assessed change in sleep patterns before and after total hip arthroplasty (THA) and total knee arthroplasty (TKA) and its relationship to patient-reported outcome measures (PROMs).MethodsBetween July 2016 and June 2018, surgical data and PROMs were collected on 780 subjects before and 12 months after THA or TKA. PROMs included Knee Injury and Osteoarthritis Outcome Score, Hip Disability and Osteoarthritis Outcome Score, patient satisfaction, and 2 questions from the Pittsburgh Sleep Quality Index.ResultsBefore surgery, 35% (270 of 780) reported poor quality sleep. Sleep quality and duration were worse in females over males, and in THA patients (39%) over TKA patients (30%; P = .011). Of those reporting bad sleep, 74% (201 of 270) were improved after arthroplasty. Satisfaction was higher in subjects reporting good sleep quality (626 of 676; 93%) compared with those reporting bad sleep quality (67 of 86; 78%) (P = .001). Sleep was positively correlated with better Hip Disability and Osteoarthritis Outcome Score/Knee Injury and Osteoarthritis Outcome Score (r = 0.2-0.3).ConclusionImprovement in sleep quality and duration can be expected after THA and TKA and is associated with better outcome scores and satisfaction.     

Changes in Patient Reported Outcome Measure Scores From Initial Presentation to Day-of-Surgery in Patients Undergoing Hip and Knee Arthroplasty

BackgroundIt is not well understood how patient reported outcome measures (PROMs) change from initial presentation to day-of-surgery (DOS). This study sought to quantify preoperative PROM changes for hip and knee arthroplasty patients.MethodsA retrospective review was performed on primary total hip, total knee, and partial knee arthroplasty patients from October 2020 through January 2021. Trends in preoperative Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR), and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) scores were compared using scores at initial presentation in the ambulatory clinic and at a time near the date-of-surgery. A total of 497 patients possessed 2 preoperative PROMIS-PF (497/497), HOOS-JR (152/497), or KOOS-JR (258/497) surveys.ResultsThere was no significant statistical difference in mean PROM scores between initial presentation and DOS PROMIS-PF or HOOS-JR scores. Only KOOS-JR demonstrated a significant statistical difference of 2 ± 14 (P = .002) when comparing initial versus preoperative scores. Partial knee arthroplasty patients saw a strong positive correlation (r = 0.77) between initial PROMIS-PF and DOS scores. However, mean absolute value changes on an individual level were 4 ± 4, 11 ± 39, and 11 ± 10 for PROMIS-PF, HOOS-JR, and KOOS-JR, respectively, indicating the presence of meaningful patient-level score changes as based on previously published anchor-based minimal clinically important differences.ConclusionPROMs collected during the preoperative period demonstrated wide variability at an individual level, but not at a population level. Collection at both time points may be necessary in order to understand the clinical impact of surgery on these patients.     

Monitoring Patient Recovery After THA or TKA Using Mobile Technology

Background

Smartphones offer the possibility of assessing recovery of mobility after total hip or knee arthroplasty (THA or TKA) passively and reliably, as well as facilitating the collection of patient-reported outcome measures (PROMs) with greater frequency.

Questions/Purposes

We investigated the feasibility of using mobile technology to collect daily step data and biweekly PROMs to track recovery after total joint arthroplasty.

Methods

Pre- and post-operative daily steps were recorded in prospectively enrolled patients (128 THA and 139 TKA) via an app, which uses the phone’s accelerometer. During 6-month follow-up, patients also completed PROMs (the pain numeric rating scale, the Hip Disability and Osteoarthritis Outcome Score Joint Replacement [HOOS JR] and the Knee Injury and Osteoarthritis Outcome Score Joint Replacement [KOOS JR]), and HOOS or KOOS JR quality of life domain via a mobile-enabled web link.

Results

At least 6 months of follow-up was completed by 65% for THA and 68% for TKA patients. Reasons for non-completion included time commitment, phone battery, app issues, and health complications. Responses from 78% of requested PROMs were returned with 96% of patients returning at least one post-operative PROM. Step data were available from 92% of days from male patients and 86% of days from female patients. The most robust recovery occurred early, within the first 2 months. The groups with higher pre-operative steps were more likely to recover their maximum daily steps at an earlier time point. Correlations between step counts and PROMs scores were modest.

Conclusion

Assessing large amounts of post-TKA and post-THA step data using mobile technology is feasible. Completion rates were good, making the technology very useful for collecting frequent PROMs. Being unable to ensure that patients always carried their phones limited our analysis of the step counts.

     

A Weighted Scoring System Based on Preoperative and Long-Term Patient-Reported Outcome Measures to Guide Timing of Knee Arthroplasty

BackgroundThere is currently no existing consensus regarding timing of knee arthroplasty. This study aimed to develop a weighted scoring system from patient-reported outcome measures (PROMs) to guide timing of knee arthroplasty based on preoperative severity and long-term effectiveness.MethodsProspectively collected data of 766 total knee arthroplasties (TKAs) and 382 unicompartmental knee arthroplasties (UKAs) at a single institution were analyzed. PROMs were assessed preoperatively and at 10 years using the Knee Society Score (KSS), Oxford Knee Score (OKS), and Short Form-36 physical component score (SF-36 PCS). Receiver operating characteristic analysis identified thresholds where preoperative PROMs predicted 10-year clinically meaningful improvements (minimal clinically important difference [MCID]). Threshold weights were assigned to PROMs based on their ability to predict MCID in isolation or in combination.ResultsPoorer baseline PROMs predicted 10-year MCID attainments. The threshold of 49.5 points for the KSS, 30.5 points for the OKS, and 40.7 points for the SF-36 PCS and 55.5 points for the KSS, 33.5 points for the OKS, and 40.5 points for the SF-36 PCS was weighted 1 point for predicting MCID in 1 PROM for TKA and UKA, respectively. The threshold of 33.4 and 33.9 points for the SF-36 PCS was weighted 2 points for predicting MCID in 2 PROMs, whereas 29.3 and 31.3 points for the SF-36 PCS were weighted 3 points for predicting MCID in 3 PROMs for TKA and UKA, respectively. The sum of weighted components from 0 (lowest) to 5 (highest) represented likelihood for long-term benefits at 10 years.ConclusionThis scoring system is a useful clinical adjunct for deciding timing of knee arthroplasty and prioritizing patients in institutions with long waitlists.Level of EvidenceII.     

Robotics Versus Navigation Versus Conventional Total Hip Arthroplasty: Does the Use of Technology Yield Superior Outcomes?

BackgroundThe use of technology such as navigation and robotic systems may improve the accuracy of component positioning in total hip arthroplasty (THA), but its impact on patient-reported outcome measures (PROMs) remains unclear. This study aims to elucidate the association between the use of intraoperative technology and PROMs in patients who underwent primary THA.MethodsWe retrospectively reviewed a consecutive series of patients who underwent primary THA between 2016 and 2020 and answered PROM questionnaires. Patients were separated into 3 groups depending on intraoperative technology utilization: computer-assisted navigation, robotic-assisted, or no technology (conventional) THA. Forgotten Joint Score-12 and Hip disability and Osteoarthritis Outcome Score, Joint Replacemen scores were collected at various time points. Demographic differences were assessed with chi-square and analysis of variance. Mean scores between groups were compared using univariate analysis of covariance, controlling for all significant demographic differences.ResultsOf the 1960 cases identified, 896 used navigation, 135 used robotics, and 929 used no technology. There were significant statistical differences in one-year Hip disability and Osteoarthritis Outcome Score, Joint Replacement scores (85.23 vs 85.95 vs 86.76, respectively; P = .014) and two-year Forgotten Joint Score-12 scores (64.72 vs 73.35 vs 74.63, respectively; P = .004) between the 3 groups. However, these differences did not exceed the mean clinically important differences. Length of stay was statistically longest for patients who underwent conventionally performed THA versus navigation and robotics (2.22 vs 1.46 vs 1.91, respectively; P < .001). Surgical time was significantly longer for cases performed using robotics versus navigation and conventionally (119.61 vs 90.35 vs 95.35, respectively; P < .001).ConclusionStatistical differences observed between all modalities are not likely to be clinically meaningful with regard to early patient-reported outcomes. Although intraoperative use of technology may improve the accuracy of implant placement, these modalities have not yet translated into improved early reported functional outcomes.Level III EvidenceRetrospective cohort.     

What Are the Benefits of Hip Resurfacing in Appropriate Patients? A Retrospective,Propensity Score-Matched Analysis

Background

Hip arthritis is one of the major causes of disability worldwide. Hip resurfacing arthroplasty (HRA) has emerged in recent years as an alternative to total hip arthroplasty (THA), but complications of HRA have limited the patient population to younger male patients with primary osteoarthritis and large hip anatomy. How the functional benefits of HRA in this population compare with those of THA is not entirely clear.

Questions/Purposes

The primary aim of this study was to determine whether there were differences in hip disability and patient satisfaction with surgery between these two groups at 2 years after surgery, using patient-reported outcome measures (PROMs) and subjective measures of patient satisfaction. Additionally, we sought to determine whether there were differences in post-operative discharge disposition, revision rates, or adverse events.

Methods

We searched an institutional database to identify patients undergoing unilateral HRA or THA between January 2007 and July 2011 who met today’s recommended criteria for HRA: younger male patients with large-enough hip anatomy to make surgery viable (a femoral head of at least 48 mm in HRA patients and, in THA patients, an acetabular shell size of 54 mm, the minimum outer shell size that could accommodate a femoral head component of 48 mm; for matching purposes, acetabular shell size in THA was used as a surrogate for the femoral head size used in HRA). We used propensity score matching to control for potentially confounding pre-operative variables and administered the Hip Disability and Osteoarthritis Outcome Score (HOOS) survey, including its subdomains, at the 2-year mark. We also assessed differences between groups in Lower Extremity Activity Scale scores, 12-item Short Form Health Survey results, and answers regarding satisfaction with surgery. We calculated minimal detectable change, minimum clinically important change, and substantial clinical benefit using anchor-based techniques for multiple outcome measures.

Results

There were 251 patients in each group. HRA patients scored significantly higher than THA patients on the 2-year HOOS sports and recreation (92 versus 87, respectively) and on rates of overall satisfaction (94% versus 89%, respectively). The HRA group also had a greater chance of achieving minimum clinically important change (18.75 points) in the HOOS sports and recreation subdomains than the THA group (97% versus 91%). No significant difference was found in 6-month adverse event rates. HRA patients also had a significantly shorter mean hospital stay, a higher rate of discharge to home, and a lower incidence of a “significant” limp after surgery.

Conclusion

HRA may provide a functional benefit in sports and recreation and greater satisfaction in patients who meet the current criteria for HRA. Because these benefits may be small, pre-operative counseling should focus on balancing the possible functional benefits against the longer-term risks associated with metal-on-metal bearings.

     

Navigated and Robot-Assisted Technology in Total Knee Arthroplasty: Do Outcome Differences Achieve Minimal Clinically Important Difference?

BackgroundIn total knee arthroplasty (TKA), computer-assisted navigation (N-TKA) and robotic-assisted methods (RA-TKA) are intended to increase precision of mechanical and component alignment. However, the clinical significance of published patient-reported outcome measure (PROM) differences in comparison to conventional TKA (C-TKA) is unknown.MethodsA systematic review was performed to identify all studies reporting perioperative PROMs for either primary N-TKA or RA-TKA with a C-TKA comparison cohort with a minimum 1-year follow-up. Relative improvements in PROMs for the two cohorts were compared to published minimal clinically important difference (MCID) values.ResultsAfter systematic review, 21 studies (N = 3,214) reporting on N-TKA and eight studies (N = 1,529) reporting on RA-TKA met inclusion criteria. Eighteen of 20 studies (90%) reported improved radiographic outcomes with N-TKA relative to C-TKA; five of five studies reported improved radiographic outcomes with RA-TKA relative to C-TKA. Five of 21 studies (24%) reported statistically significant greater improvements in clinical PROMs for N-TKA relative to C-TKA, whereas only two (10%) achieved clinical significance relative to MCID on a secondary analysis. One of 8 studies (13%) reported statistically significant greater improvements in PROMs for RA-TKA relative to C-TKA, whereas none achieved clinical significance relative to MCID on a secondary analysis. No studies reported a significant difference in revision rates.ConclusionWhile most studies comparing RA-TKA and N-TKA with C-TKA demonstrate improved radiographic alignment outcomes, a minority of studies reported PROM differences that achieve clinical significance. Future studies should report data and be interpreted in the context of clinical significance to establish patient and surgeon expectations for emerging technologies.     

Machine Learning Algorithms Can Use Wearable Sensor Data to Accurately Predict Six-Week Patient-Reported Outcome Scores Following Joint Replacement in a Prospective Trial

BackgroundTracking patient-generated health data (PGHD) following total joint arthroplasty (TJA) may enable data-driven early intervention to improve clinical results. We aim to demonstrate the feasibility of combining machine learning (ML) with PGHD in TJA to predict patient-reported outcome measures (PROMs).MethodsTwenty-two TJA patients were recruited for this pilot study. Three activity trackers collected 35 features from 4 weeks before to 6 weeks following surgery. PROMs were collected at both endpoints (Hip and Knee Disability and Osteoarthritis Outcome Score, Knee Osteoarthritis Outcome Score, and Veterans RAND 12-Item Health Survey Physical Component Score). We used ML to identify features with the highest correlation with PROMs. The algorithm trained on a subset of patients and used 3 feature sets (A, B, and C) to group the rest into one of the 3 PROM clusters.ResultsFifteen patients completed the study and collected 3 million data points. Three sets of features with the highest R² values relative to PROMs were selected (A, B and C). Data collected through the 11th day had the highest predictive value. The ML algorithm grouped patients into 3 clusters predictive of 6-week PROM results, yielding total sum of squares values ranging from 3.86 (A) to 1.86 (C).ConclusionThis small but critical proof-of-concept study demonstrates that ML can be used in combination with PGHD to predict 6-week PROM data as early as 11 days following TJA surgery. Further study is needed to confirm these findings and their clinical value.