Michael Bret Anderson

Introduction: Step counts are increasingly used to assess mobility and track recovery following total knee arthroplasty (TKA). The purpose of this study was to assess the convergent validity of step count data captured by a smart implantable device (SID) in comparison with step counts derived from established, validated sensor-based technology. Methods: A secondary analysis of an anonymized commercial database (N = 7861, median age: 68, female: 59%, median BMI: 31.7) of patients who received an SID and used a digital care management application (App) with or without a smart watch. The SID recorded “qualified steps”, defined as periods of walking for at least seven steps that met predefined acceleration and cadence thresholds between 7 am and 10 pm. The App collected total daily step counts via smartwatch and/or smartphone. Pearson correlations were calculated between SID and App data at 30, 90, and 180 days post-operative. Step counts at 30, 90, and 180 days post-operative were compared between groups with the Mann–Whitney U test. Statistical significance was assessed at p < 0.001. Results: Step counts increased throughout the recovery period as measured by all three devices. SID-captured fewer qualified steps than App-captured step counts from watch-wearers throughout the post-operative period (p ≤ 0.001). SID step counts were similar to App step counts at 30 days post-operative and greater than App step counts at 90 and 180 days post-operative (p < 0.001). There were significant (p < 0.001), moderate correlations (r = 0.62 to r = 0.74) between step counts collected by the SID and App for both watch-wearers and smartphone-carriers at 30, 90, and 180 days post-operative. Conclusions: The SID’s qualified step metric demonstrated consistent, moderate, correlations with app-based step counts across 30, 90, and 180 days. While smartwatch-based tools recorded higher absolute step counts, both technologies reflected similar recovery trajectories.

Introduction: The purpose of this study was to evaluate the relationship between 1-month pain scores and 3-month postoperative satisfaction and investigate whether an immediate postoperative pain score cutoff exists between satisfied and dissatisfied patients. Methods: This was a secondary analysis of a multicenter, longitudinal, cohort study comprised total knee arthroplasty (TKA) patients (n = 1763) using a digital care management platform. Pain was assessed at 1 month postoperatively through an 11-point numeric rating scale (NRS). Satisfaction was assessed at 3 months postoperative through the Knee Society composite satisfaction score (KSS). Patients were stratified into satisfied (KSS >30) and dissatisfied (KSS P < 0.001). Based on the best-fit line, the cutoff for dissatisfaction occurs with an NRS for pain of >4.0. The model achieves an area under curve (AUC) of 0.73 (SD = 0.02), with a maximum f1-score of 0.65, corresponding to sensitivity = 0.87 and specificity = 0.44. Conclusion: One-month postoperative pain scores greater than 4.0 were associated with patient dissatisfaction at 3 months postoperatively. Assessing pain in the immediate postoperative period can provide clinicians with diagnostic data that may help detect patients at risk for a poor prognosis 3 months following TKA.

Background: After unilateral total knee arthroplasty (TKA), patients place more weight on the nonsurgical limb than the surgical limb. The objective of this study was to determine the possibility of providing live biofeedback during early recovery of patients undergoing unilateral TKA and to determine the necessary sample size for future trials. Methods: Twenty patients with unilateral TKA were randomized into two groups: a feedback group and a control group. Inclusion criteria included no contralateral knee pain and aid-free walking before surgery. There were 8 patients in the feedback group and 10 in the control group. Compliance with the recommended training was 91%. The feedback group trained with an insole device for 15 min a day for 4 weeks, along with normal physiotherapy. The control group received normal physiotherapy only. Gait parameters were recorded on level ground at two and six weeks. The primary outcome was the percent loading rate. The secondary outcomes included gait speed, cadence, percent peak force, and pain. Results: Patients within the feedback group showed a small, non-significant trend toward a higher precent load rate at 6 weeks compared to the control group in level walking (p = 0.92). Conclusions: Our findings indicate that live biofeedback on a gait parameter, like percent load rate, can be provided by the mentioned system and may support immediate changes in gait parameters. The compliance of 91% with training and no reported adverse events indicates that the system was easy to use. Following TKA, there may be a potential exploratory use of mobile, real-time biofeedback to help address gait abnormalities and accelerate rehabilitation. This clinical trial was registered at clinicaltrials.gov (Identifier: NCT03673293) on 14 September 2018. This study was conducted in accordance with the Declaration of Helsinki and approved by the institutional review board of the University of Utah (IRB_00110935) on 10 September 2018.

Background: The purpose of this study was to clinically characterize neutrally satisfied patients and compare outcomes between satisfied, dissatisfied, and neutral patients. Methods: This was a secondary analysis from data collected in a multicenter longitudinal cohort study comprising total knee arthroplasty (TKA) patients using a digital care management platform. The Knee Society Score (KSS) satisfaction survey was administered at post-operative 90 days, and dissatisfaction was defined as a composite score of less than 20, satisfied as a score equal to or greater than 30, and neutral as a score of 20 up to 29. Patient-reported outcome measures (PROMs) were assessed pre-operatively and at post-operative one, three, six, and twelve months. Results: Approximately 58% of patients were satisfied (n = 1486), 29.4% neutral (n = 747), and 12.2% dissatisfied (n = 311). Neutral and dissatisfied patients were younger and more likely to be female and had lower pre-operative KSS scores compared to satisfied patients, though statistical differences were found between all groups. Pre-operative pain was significantly less in satisfied compared to neutral or dissatisfied patients. Changes in the pre-operative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) displayed significant differences between all groups at all time points, with greater improvements in satisfied versus neutral patients and neutral versus dissatisfied patients. Similarly, satisfied patients experienced significantly greater improvements in pain and KSS scores at post-operative three months, and neutral patients improved more than dissatisfied patients. Conclusions: Neutral patients present with distinctively different clinical outcomes compared to satisfied or dissatisfied patients and should be classified separately as neutral.

Cost savings were achieved with the use of a smartphone-based care management platform, considering several health care resources following knee arthroplasty procedures without negatively impacting clinical outcomes.

Background/Objectives: Patient acceptable symptom state (PASS) thresholds have been used as a marker of good functional outcome following total knee arthroplasty (TKA) but have not been applied to pre-operative subjective function. This study aimed to compare the outcomes of patients above and below PASS thresholds prior to TKA. Methods: A secondary analysis of a multicenter prospective observational study was used, including 1182 patients prescribed a smartphone-based care management platform following TKA with pre-operative and 1-year KOOS JR scores available. Patient demographics, pain, satisfaction, and KOOS JR were compared between those above and below PASS pre-operatively by student t-test. Logistic regression was used to quantify the odds of decline or no improvement at 1 year. Results: In this cohort, 191 (16.2%) KOOS JR scores were above PASS thresholds prior to TKA. Those above PASS reported lower pain pre-operatively (3.7 ± 1.9 vs. 6.0 ± 1.9, p < 0.0001) and less pain reduction at 90 days (−1.4 ± 2.5 vs. −3.2 ± 2.6, p < 0.0001). Patients above PASS also demonstrated higher KSS satisfaction scores pre-operatively (20.7 ± 7.9 vs. 12.1 ± 6.7, p < 0.0001) with less improvement (9.9 ± 10.6 vs. 16.5 ± 11.2, p < 0.0001) at 90 days. In logistic regression, those above PASS pre-operatively were 5.1 times more likely to report a decline or no improvement in KOOS JR at 1 year (5.10 95% CI 2.73–9.53, p < 0.0001). Conclusions: Patients above previously defined PASS thresholds who presented for TKA appreciated less improvement in pain and satisfaction and were more likely to experience functional decline or no improvement in KOOS JR post-operatively. The application of PASS thresholds pre-operatively may be useful for patient selection or guidance of patient expectations.

The COVID-19 pandemic has triggered the adoption of new technologies to reduce the need for in-person physical therapy (PT). This study evaluated the impact of the COVID-19 pandemic on PT utilization and outcomes of patients prescribed a smartphone-based care management platform (sbCMP) for self-directed rehabilitation (SDR). A secondary analysis of data collected in a multicenter, prospective cohort trial investigating a mobile platform to deliver SDR after arthroplasty was performed. Patients who used the sbCMP for 2 weeks prior to undergoing partial knee arthroplasty (PKA), total knee arthroplasty (TKA), or total hip arthroplasty (THA) and provided 3 months of post-operative data were included. Use of adjunct PT at 3 months, step counts, and KOOS JR and HOOS JR scores were compared during the early versus late pandemic period. The cohort data was available for 1665 patients. Use of SDR without adjunct PT was higher in the early period of the COVID-19 pandemic in TKA (35.3% vs. 27.6%, p = 0.03) and THA (72.5% vs. 59.3%, p < 0.001), but not in the PKA cohort (58.9% vs. 53.3%, p = 0.53). Post-operative step counts improved at 3 months compared to pre-operative levels in all procedure types. Change in HOOS JR and KOOS JR scores from pre-operative to post-operative levels were similar by pandemic period in all cohorts. Use of SDR increased early during the COVID-19 pandemic, corresponding to pandemic restrictions, without negatively impacting patient outcomes. SDR facilitated via a sbCMP may be beneficial for patients unable or unwilling to participate in traditional PT visits.

Patients with end-stage osteoarthritis are recommended to engage in physical activity (PA) to reduce pain and improve function but may avoid PA due to joint pain. Our goal was to investigate patient-reported outcomes and objective mobility metrics (step counts) in total hip arthroplasty (THA) patients as a function of pre-operative PA levels. In total, 1647 patients enrolled in a multicenter prospective cohort study investigating a smartphone-based care management platform for self-directed rehabilitation that underwent THA and were included in analysis. The entire cohort’s step count was divided into quartiles to categorize patients with low, moderate, and high baseline PA. Outcomes including pain, EQ-5D-5L, HOOS JR, and step counts were compared according to activity group by ANOVA. Pre-operative pain scores were lowest, with smallest improvements, in the high-baseline PA group. Low-PA patients demonstrated the greatest improvements in EQ-5D-5L, while changes in EQ-VAS, HOOS JR, and satisfaction were similar between groups. Low- and moderate-PA patients increased physical activity by six weeks, reaching 180% and 114% of pre-operative steps; high-PA patients did not return to full step counts until one-year post-operation. Patients who perform high levels of PA undergoing THA report lower levels of pain and higher function pre-operatively but may appreciate less improvement in PA up to one year post-operatively. These results may be helpful in appropriate counseling of patient expectations prior to surgery.

Purpose: Obesity has been identified as a risk factor for postoperative complications in patients undergoing total hip arthroplasty (THA). This study aimed to investigate patient-reported outcomes, pain, and satisfaction as a function of body mass index (BMI) class in patients undergoing THA. Methods: 1736 patients within a prospective observational study were categorized into BMI classes. Pre- and postoperative Hip disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR), satisfaction, and pain scores were compared by BMI class using one-way ANOVA. Results: Healthy weight patients reported the highest preoperative HOOS JR (56.66 ± 13.35) compared to 45.51 ± 14.45 in Class III subjects. Healthy weight and Class III patients reported the lowest (5.65 ± 2.01) and highest (7.06 ± 1.98, p < 0.0001) preoperative pain, respectively. Changes in HOOS JR scores from baseline suggest larger improvements with increasing BMI class, where Class III patients reported an increase of 33.7 ± 15.6 points at 90 days compared to 26.1 ± 17.1 in healthy weight individuals (p = 0.002). Fewer healthy weight patients achieved the minimal clinically important difference (87.4%) for HOOS JR compared to Class II (96.5%) and III (94.7%) obesity groups at 90 days postoperatively. Changes in satisfaction and pain scores were largest in the Class III patients. Overall, no functional outcomes varied by BMI class postoperatively. Conclusion: Patients of higher BMI class reported greater improvements following THA. While risk/benefit shared decision-making remains a personalized requirement of THA, this study highlights that utilization of BMI cutoff may not be warranted based on pain and functional improvement.