Staying Ahead of the Curve: The Case for Recovery Curves in Total Knee Arthroplasty.

BACKGROUND: Sensor technology embedded within the total knee arthroplasty (TKA) implant has the potential to record data that can track recovery and provide diagnostic information. In this study, we introduce the concept of physical function recovery curve analytics, which are created from daily spatial-temporal gait metrics and step counts from a large cohort of TKA patients. METHODS: In our study population, 258 patients underwent a primary TKA with a smart implanted tibial extension between October 4, 2021, and July 15, 2022, by 33 surgeons. The average age was 63 years, with 138 (54%) women. All kinematic data was collected on a Health Insurance Portability and Accountability Act (HIPAA)-compliant cloud data management platform. RESULTS: Summaries of the gait parameters at 6 weeks are suggestive of differences between people over and under 65 years, with the older patients walking more slowly and having shorter stride lengths. The 6-week percentiles demonstrated a strong, linear correlation to the 12-week percentiles for each gait parameter, with correlation coefficients ranging from 0.87 to 0.92. CONCLUSIONS: A novel screening gait test at 6 weeks shows promising results for predicting patients who will likely have poor recovery based on at least 1 gait parameter recovery curve at 12 weeks with high sensitivity and specificity. A future study is needed to validate the screening tool with an independent set of patients.

A unique case report of a revision extensor mechanism reconstruction using Marlex mesh in the setting of proximal tibial bone deficiency: The tantalum clamshell technique.

Extensor mechanism (EM) disruption is a rare but severe complication of total knee arthroplasty (TKA) that can greatly impair function. Treatment options for chronic patella tendon ruptures include primary repair, autograft augmentation, and reconstruction with allograft or synthetic material. Despite various techniques, failures can occur, and options for reconstruction after a failed allograft or mesh are limited, especially if the tibial component is well-fixed and cannot be easily removed, and if there is proximal tibial deficiency from a previous failed EM allograft. This case report presents a novel solution for revision EM reconstruction in a 72y.o. female patient with a history of multiple EM failures using an off-label Trabecular Metal Cone-Mesh-Cone (TM CMC) clamshell construct. The surgical procedure involved the removal of a non-viable allograft from the knee joint and the creation of a custom trabecular metal (TM) clamshell construct with a Marlex mesh graft in between the two TM implants. The customized TM cone was designed to cover the deficient anterior tibia and wrap around the ingrown TM cone. The Marlex mesh was cemented between the existing implant and the customized TM cone, and the construct was secured in place with two cancellous screws. The mesh was tunneled between soft tissue to prevent contact with the implant and rotated scar tissue was interposed to prevent abrasion of the mesh on the implant surfaces. The patient tolerated the procedure well and no complications were noted postoperatively. At a follow-up 12 months after the operation the patient remains satisfied with the result.

Is Preoperative Weight Reduction in Patients Who Have Body Mass Index ≥ 40 Associated With Lower Complication Rates After Primary Total Hip Arthroplasty?

BACKGROUND: Given the heightened risk of postoperative complications associated with obesity, delaying total hip arthroplasty (THA) in patients who have a body mass index (BMI) > 40 to maximize preoperative weight loss has been advocated by professional societies and orthopaedic surgeons. While the benefits of this strategy are not well-understood, previous studies have suggested that a 5% reduction in weight or BMI may be associated with reduced complications after THA. METHODS: We identified 613 patients who underwent primary THA in a single institution during a 7-year period and who had a BMI >40 recorded from 9 to 12 months prior to surgery. Subjects were stratified into 3 cohorts based on whether their baseline BMI decreased by >5% (147 patients, 24%), was unchanged ( ± 5%) (336 patients, 55%), or increased by >5% (130 patients, 21%) on the day of surgery. The frequency of 90-days Hip Society and Centers for Medicare & Medicaid Services complications was compared between these cohorts. There were significant baseline differences between the cohorts with respect to baseline American Society of Anesthesiologists class (P < .001) and hemoglobin A1C (P = .011), which were accounted for in a multivariate regression analysis. RESULTS: In univariate analysis, there was a lower incidence of readmission (P = .025) and total complications (P = .005) in the increased BMI cohort. The overall complication rate was 18.4% in the decreased BMI cohort, 17.6% in the unchanged cohort, and 6.2% in the increased cohort. However, multivariable regression analysis controlling for potential confounders did not find that preoperative change in BMI was associated with differences in 90-days complications between cohorts (P > .05). CONCLUSIONS: Patients who have a BMI >40 and achieved a clinically significant (>5%) BMI reduction prior to THA did not have a lower risk of 90-days complications or readmissions. Thus, delaying THA in these patients to encourage weight loss may result in restricting access to a beneficial surgery without an appreciable safety benefit.

The Use of Aspirin for Venous Thromboembolism Prophylaxis in Patients Who Have Morbid Obesity Undergoing Primary and Revision Total Joint Arthroplasty.

BACKGROUND: Venous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index (BMI) > 40 undergoing primary and revision total joint arthroplasty, and second, to investigate aspirin (ASA) efficacy and safety. METHODS: We identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision total joint arthroplasty from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any VTE event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively. RESULTS: The total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = .669). The VTEs consisted of 6 deep venous thromboses (DVTs), 14 pulmonary embolisms, and one concomitant deep venous thrombosis and pulmonary embolism. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant (AC) 0.5% (n = 6), and AC alone 0.4% (n = 5) (P = .954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + AC, or AC alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = .351). CONCLUSIONS: The use of aspirin 325 and 81 mg was found to have similar VTE rates as aspirin + ACs and ACs alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE.

Substantial Weight Loss May Not Improve Early Outcomes of Total Knee Arthroplasty in the Morbidly Obese.

BACKGROUND: Body mass index (BMI) cutoffs for morbidly obese patients otherwise indicated for total knee arthroplasty (TKA) have been widely proposed and implemented, though they remain controversial. Previous studies suggested that a 5% reduction in BMI may be associated with fewer postoperative complications. Thus, the purpose of this study was to determine whether a substantial reduction in preoperative BMI in morbidly obese patients improved 90-day outcomes after TKA. METHODS: There were 1,270 patients who underwent primary TKA at a single institution and had a BMI > 40 recorded during the year prior to surgery. Patients were stratified into three cohorts based on whether their BMI within 3 months to 1 year preoperatively had decreased by ≥ 5% (228 patients [18%]); increased by ≥ 5% (310 [24%]); or remained unchanged (within 5%) (732 [58%]) on the day of surgery. There were several baseline differences between the cohorts with respect to medical comorbidities. The rate of 90-day complications and six-week patient-reported outcome measures were compared via univariate and multivariable analyses. RESULTS: On univariate analysis, individual and total complication rates were similar between the cohorts (P > .05). On multivariable logistic regression, the risk of complications was similar in patients who had decreased versus unchanged BMI (OR [odds ratio] 1.0; P = .898). However, there was a higher risk of complications in the increased BMI cohort compared to those patients who had an unchanged BMI (OR 1.5; P = .039). The six-week patient-reported outcome measures were similar between the cohorts. CONCLUSIONS: Patients who have a BMI > 40 who achieved a meaningful reduction in BMI prior to TKA did not have a lower rate of 90-day complications than those whose BMI remained unchanged. Furthermore, considering that nearly one in four patients experienced a significant increase in BMI while awaiting surgery, postponing TKA may actually be detrimental.

How Active Are Our Patients in the First 6 Weeks Following Total Knee Arthroplasty?

BACKGROUND: Patient activity after total knee arthroplasty (TKA) surgery has been estimated through patient-reported outcome measures. The use of data from an implanted sensor that transmits daily gait activity provides a more objective, complete recovery trajectory. METHODS: In this retrospective analysis of 794 patients who received a TKA with sensors in the tibial extension between October 4, 2021, and January 13, 2023, the average age of the patients was 64 years, and the cohort was 54.9% women. During the 6-week postoperative period, 90.3% of patients transmitted data. Patient activity in terms of qualified step count, cadence, walking speed, stride length, functional tibial range of motion (ROM), and functional knee ROM were compared at 1 week, 3 weeks, and 6 weeks postoperatively. RESULTS: All gait parameters increased in the first 6 weeks postsurgery: qualified step count increased 733%, cadence increased 22%, walking speed increased 50%, stride length increased 17%, tibial ROM increased 19%, and functional knee ROM increased 14%. There were statistically significant differences at both postoperative periods (P = .029, P < .001, and P < .001 at 3 and 6 weeks, respectively) in step counts for different body mass index (BMI) categories, with qualified step counts decreasing with increasing BMI. Patients under 65 years tended to have a higher qualified step count than those 65 and older at all time points, but these differences were not statistically significant. Men had significantly higher step counts than women (P < .001 at 1, 3, and 6 weeks). CONCLUSIONS: Initial results with an implanted sensor that collects data during activities of daily living confirm that 90% of patients transmit objective gait metrics daily after TKA surgery. Those results differ by sex and BMI. LEVEL OF EVIDENCE: III Retrospective Cohort Study.

Obesity Severity Does Not Associate With Rate, Timing, or Invasiveness of Early Reinterventions After Total Knee Arthroplasty.

BACKGROUND: The use of body mass index (BMI) cutoff values has been suggested for proceeding with total knee arthroplasty (TKA) in obese patients. However, the relationship between obesity severity and early reoperations after TKA is poorly defined. This study evaluated whether increased World Health Organization (WHO) obesity class was associated with risk, severity, and timing of reintervention within one year after TKA. METHODS: There were 8,674 patients from our institution who had a BMI ≥ 30 and underwent unilateral TKA for primary osteoarthritis between 2016 and 2021. Patients were grouped by WHO obesity class: 4,456 class I (51.5%), 2,527 class II (29.2%), and 1,677 class III (19.4%). A chart review was performed to determine patient characteristics and identify patients who underwent any closed or open reintervention requiring anesthesia within the first postoperative year. Regression analyses were performed to identify variables associated with increased odds ratios (ORs) for requiring a reintervention, its timing, and invasiveness. RESULTS: There were 158 patients (1.8%) who required at least one reintervention, and 15 patients (0.2%) required at least 2 reinterventions. Reintervention rates for obesity classes I, II, and III were 1.8% (n = 81), 2.0% (n = 51), and 1.4% (n = 23), respectively. There were 65 closed procedures (41.1%), 47 minor procedures (29.7%), 34 open with or without liner exchange (21.5%), and 12 revisions with component exchange (7.6%). Obesity class was not associated with reintervention rate (P = .3), timing (P = .36), or invasiveness (P = .93). Diabetes (odds ratio [OR] = 2.47; P = .008) was associated with a need for reintervention. Non-Caucasian race (OR = 1.7; P = .01) and Charlson comorbidity index (OR = 2.1; P = .008) were associated with earlier reintervention. No factors were associated with the invasiveness of reintervention. CONCLUSIONS: The WHO obesity class did not associate with rate, timing, or invasiveness of reintervention after TKA in obese patients. These findings suggest that policies that restrict the indication for elective TKA based only on a BMI limit have limited efficacy in reducing early reintervention after TKA in obese patients. LEVEL OF EVIDENCE: III.

What Is the Role of a Periarticular Injection for Knee Arthroplasty Patients Receiving a Multimodal Analgesia Regimen Incorporating Adductor Canal and Infiltration Between the Popliteal Artery and Capsule of the Knee Blocks? A Randomized Blinded Placebo-Controlled Noninferiority Trial.

BACKGROUND: Optimal analgesic protocols for total knee arthroplasty (TKA) patients remain controversial. Multimodal analgesia is advocated, often including peripheral nerve blocks and/or periarticular injections (PAIs). If 2 blocks (adductor canal block [ACB] plus infiltration between the popliteal artery and capsule of the knee [IPACK]) are used, also performing PAI may not be necessary. This noninferiority trial hypothesized that TKA patients with ACB + IPACK + saline PAI (sham infiltration) would have pain scores that were no worse than those of patients with ACB + IPACK + active PAI with local anesthetic. METHODS: A multimodal analgesic protocol of spinal anesthesia, ACB and IPACK blocks, intraoperative ketamine and ketorolac, postoperative ketorolac followed by meloxicam, acetaminophen, duloxetine, and oral opioids was used. Patients undergoing primary unilateral TKA were randomized to receive either active PAI or control PAI. The active PAI included a deep injection, performed before cementation, of bupivacaine 0.25% with epinephrine, 30 mL; morphine; methylprednisolone; cefazolin; with normal saline to bring total volume to 64 mL. A superficial injection of 20 mL bupivacaine, 0.25%, was administered before closure. Control injections were normal saline injected with the same injection technique and volumes. The primary outcome was numeric rating scale pain with ambulation on postoperative day 1. A noninferiority margin of 1.0 was used. RESULTS: Ninety-four patients were randomized. NRS pain with ambulation at POD1 in the ACB + IPACK + saline PAI group was not found to be noninferior to that of the ACB + IPACK + active PAI group (difference = 0.3, 95% confidence interval [CI], [-0.9 to 1.5], P = .120). Pain scores at rest did not differ significantly among groups. No significant difference was observed in opioid consumption between groups. Cumulative oral morphine equivalents through postoperative day 2 were 89 ± 40 mg (mean ± standard deviation), saline PAI, vs 73 ± 52, active PAI, P = .1. No significant differences were observed for worst pain, fraction of time in severe pain, pain interference, side-effects (nausea, drowsiness, itching, dizziness), quality of recovery, satisfaction, length of stay, chronic pain, and orthopedic outcomes. CONCLUSIONS: For TKA patients given a comprehensive analgesic protocol, use of saline PAI did not demonstrate noninferiority compared to active PAI. Neither the primary nor any secondary outcomes demonstrated superiority for active PAI, however. As we cannot claim either technique to be better or worse, there remains flexibility for use of either technique.

The John N. Insall Award: Does Melatonin Improve Subjective Sleep Quality After Total Knee Arthroplasty? A Randomized, Placebo-Controlled Trial.

BACKGROUND: Sleep disturbance is a common problem following total knee arthroplasty (TKA). The objective of this study was to determine if exogenous melatonin improves sleep quality following primary TKA. METHODS: A randomized, double-blind, placebo-controlled trial was conducted. A total of 172 patients undergoing unilateral TKA for primary knee osteoarthritis were randomized to receive either 5 mg melatonin (n = 86) or 125 mg vitamin C placebo (n = 86) nightly for 6 weeks. The primary outcome was the Pittsburgh Sleep Quality Index (PSQI) at 6 weeks and 90 days postoperatively. Secondary outcomes included 6-week and 90-day patient-reported outcome measures (PROMs), morphine milligram equivalents prescribed, medication compliance, adverse events, and 90-day readmissions. RESULTS: Mean PSQI scores worsened at 6 weeks before returning to the preoperative baseline at 90 days in both groups. There were no differences in PSQI scores between melatonin and placebo groups at 6 weeks (10.2 ± 4.2 versus 10.5 ± 4.4, P = .66) or 90 days (8.1 ± 4.1 versus 7.5 ± 4.0, P = .43). Melatonin did not improve the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Lower Extremity Activity Scale, Visual Analog Scale for pain, or Veterans Rand 12 Physical Component Score or Mental Component Score at 6 weeks or 90 days. Poor sleep quality was associated with worse PROMs at 6 weeks and 90 days on univariate and multivariable analyses, but melatonin did not modify these associations. There were no differences in morphine milligram equivalents prescribed, medication compliances, adverse events, or 90-day readmissions between both groups. CONCLUSIONS: Exogenous melatonin did not improve subjective sleep quality or PROMs at 6 weeks or 90 days following TKA. Poor sleep quality was associated with worse patient-reported function and pain. Our results do not support the routine use of melatonin after TKA.

COVID-19 disruptions to elective postoperative care did not adversely affect early complications or patient reported outcomes of primary TKA.

INTRODUCTION: Elective orthopedic care, including in-person office visits and physical therapy (PT), was halted on March 16, 2020, at a large, urban hospital at the onset of the local COVID-19 surge. Post-discharge care was provided predominantly through a virtual format. The purpose of this study was to assess the impact of postoperative care disruptions on early total knee arthroplasty (TKA) outcomes, specifically 90-day complications, 120-day rate of manipulation under anesthesia (MUA) and 1-year patient-reported outcome measures (PROMs). MATERIALS AND METHODS: Institutional records were queried to identify 624 patients who underwent primary, unilateral TKA for osteoarthritis and who were discharged home between 1/1/20 and 3/15/20. These patients were compared to 558 controls discharged between 1/1/19 and 3/15/2019. Cohort demographics and in-hospital characteristics were equivalent apart from inpatient morphine milligram equivalent (MME) consumption. Patient-reported access to PT (p < 0.001) and post-discharge care (p < 0.001) were worse among study patients. Study patients were prescribed fewer post-discharge PT sessions (19.8 vs. 23.5; p < 0.001) and utilized telehealth more frequently (p < 0.001). Mann-Whitney U, T, Fisher's Exact, and chi-squared tests were used to compare outcomes. RESULTS: Ninety-day CMS complications were lower among study patients (3.5% vs. 5.9%; p = 0.05). Rates of MUA were similar between groups. Study patients reported similar PROMs and marginally inferior VR-12 mental and LEAS functional outcomes at 1 year. CONCLUSION: Disruptions to elective orthopedic care in March 2020 seemed to have had no major consequences on clinical outcomes for TKA patients. Our findings question the usefulness of pre-pandemic post-discharge protocols, which may over-emphasize in-person visits and PT.

Is there a difference in mobility and inpatient physical therapy need after primary total hip and knee arthroplasty? A decade-by-decade analysis from 60 to 99 years.

INTRODUCTION: Extended inpatient rehabilitation (PT) after total hip (THA) and knee arthroplasty (TKA) has a significant impact on total care costs. As patients age, extended PT might be required following THA and TKA. This study examined the relationship between patient age, functional mobility, inpatient PT need, and discharge disposition in THA and TKA patients. MATERIALS AND METHODS: This retrospective study included patients aged 60 + undergoing primary THA or TKA between 2018 and 2020 at an orthopedic hospital. Comparing by age-decade, 7374 (3600 THA, 3774 TKA) sexagenarians, 5350 (2367 THA, 2983 TKA) septuagenarians, 1356 (652 THA, 704 TKA) octogenarians, and 78 (52 THA, 26 TKA) nonagenarians were analyzed. We compared the number of PT sessions needed for discharge clearance and the postoperative functional mobility using the Activity Measure for Post-Acute Care (AM-PAC) tool. Statistical analyses included ANOVA with post-hoc Tukey's HSD for continuous data and Chi-squared test for categorical variables. RESULTS: The number of PT sessions required for discharge clearance increased with age after THA (3.3 ± 1.9 sessions vs 3.8 ± 2.1 vs 5.0 ± 2.7 vs 6.2 ± 3.0; p < 0.01) and TKA (4.0 ± 2.1 vs 4.7 ± 3.1 vs 5.2 ± 2.8 vs 5.0 ± 1.6; p < 0.01). The functional mobility improvement as measured by AM-PAC was significantly lower for nonagenarians after THA (4.9 ± 2.8 vs 5.1 ± 2.8 vs 4.6 ± 3.3 vs 3.3 ± 3.9; p < 0.01) and TKA (5.0 ± 2.9 vs 4.7 ± 3.2 vs 3.9 ± 3.4 vs 3.2 ± 2.6; p < 0.01). CONCLUSION: Patients in their eighth and ninth decade had less improvement in functional mobility during in-hospital rehabilitation and utilized more PT services. However, clinical results in the elderly are still satisfying and the data may be helpful for resource utilization planning and risk-adjustment in value-based payment models.

Nonagenarians and Octogenarians Undergoing THA and TKA: A 10-Year Age Difference Increases Rates of In-Hospital Complications But Does Not Affect 90-Day Outcomes.

Background: The population of nonagenarians undergoing total joint arthroplasty (TJA) of the hip or knee is expected to increase, but this population may be reluctant to consider elective surgery because of their advanced age. Purpose: We sought to compare TJA outcomes between nonagenarians and octogenarians with an exact 10-year age difference. Methods: We performed a retrospective chart review, including 129 nonagenarians who underwent primary unilateral TJA for osteoarthritis in a 4-year period at a single institution and who were matched with 381 octogenarians based on sex, body mass index, Charlson Comorbidity Index, replaced joint (hip or knee), and a 10-year age difference. Ninety-day outcomes included Centers for Medicare and Medicaid Services (CMS) defined complications, unscheduled outpatient clinic visits, emergency room (ER) visits, and readmissions. No patients were lost to follow-up. Results: Nonagenarians and octogenarians had comparable rates of CMS complications (10% vs 6.3%, respectively), but nonagenarians had higher rates of CMS mechanical complications (6.2% vs 1.6%). There was 1 death in each group. Nonagenarians had longer hospital stays than octogenarians (4.1 vs 3.0 days, respectively), and a greater risk of in-hospital events and complications (60.5% vs 37.3%, respectively). The groups showed similar rates of unscheduled outpatient visits (14.7% vs 13.9%, respectively), ER visits (12.4 vs 6.6%, respectively), and readmissions (6.2% vs 7.1%, respectively). Conclusions: This retrospective study found higher rates of in-hospital complications in nonagenarians than in matched octogenarians following elective TJA, although the 2 groups showed similar rates of postdischarge complications. Further research in a larger cohort is needed.

Do obese patients benefit from a kinematic, appropriately designed total knee prosthesis?

Introduction: Modern total knee arthroplasty (TKA) using the Journey 2 implant utilizes a bicruciate stabilized (BCS) technique. However, whether bicruciate stabilized TKA is equally effective across weight classes is unknown. Methods: We identified patients who underwent primary bicruciate stabilized TKA during 2016 and 2017, at a single institution. All included patients had, at minimum, 2-year follow-up. Patients were categorized into body-mass index (BMI) groups as follows: underweight, normal, or overweight (<30 kg/m2), obese (≥30 to <35 kg/m2), and severely obese (≥35 kg/m2). Patient reported outcome measures (PROMs) were measured at baseline. Both KSS and KOOS JR, along with the Visual Analogue Scale (VAS), were also recorded at follow-up. Pre-operative, post-operative, and pre-to post-operative changes in PROMs were analyzed using analysis of variance (ANOVA) and linear regression. Results: The 292 patients had a mean age of 64.8 years and mean BMI of 32.3 kg/m2. There were 116 (39.7%) patients in the underweight, normal, or overweight group, 88 (30.1%) in the obese category, and 88 (30.1%) in the severely obese group. There were no differences between PROMs at baseline or at follow-up (p > 0.10 for all comparisons). There were also no differences in the improvement from pre-to post-operative KSS (p = 0.21) and KOOS JR (p = 0.62). Conclusions: Bicruciate stabilized TKA has similar effects on PROMs across BMI groups. These results suggest that bicruciate stabilized TKA is a viable treatment option both for low-weight and high-weight patients.

A Cadaveric Study Addressing the Feasibility of Remote Patient Monitoring Prosthesis for Total Knee Arthroplasty.

BACKGROUND: Since the COVID-19 pandemic of 2020, there has been a marked rise in the use of telemedicine to evaluate patients after total knee arthroplasty (TKA). The purpose of our study was to assess a novel stem with an embedded sensor that can remotely and objectively monitor a patient's mobility after TKA. METHODS: A single anatomically designed knee system was implanted in concert with an interconnected tibial stem extension containing 3D accelerometers, 3D gyroscopes, a power source, and a telemetry transmission capability in 3 cadaveric pelvis to toe specimens. The legs were moved by hand to preset tibial positions at full knee extension, midflexion, flexion, and back to midflexion and extension for a total of 16 trials across 6 knees. RESULTS: Sensor data were successfully transmitted with good quality of signal to an external base station. Good correlation to the range of motion of the tibia was found (mean error 0.1 degrees; root mean square error 3.8 degrees). The signal from the heel drop tests suggests the sensor could detect heel strike during activities of daily living in vivo and the potential for additional signal processing to analyze vibratory and motion patterns detected by the sensors. A frequency domain analysis of a properly cemented and poorly cemented implant during the heel drop test suggests a difference in accelerometer signal in these implant states. CONCLUSION: The results confirm signals generated from an embedded TKA sensor can transmit through bone and cement, providing accurate range of motion data and may be capable of detecting changes in prosthesis fixation remotely.

Transfusion Avoidance in Severely Anemic Total Hip and Total Knee Arthroplasty Patients: An Analysis of Risk.

Background: Allogenic blood transfusions increase the risk of multiple complications. We evaluated the influence of restricting transfusions in adults with osteoarthritis that underwent total hip or knee arthroplasty (THA/TKA) with severe postoperative anemia. Material and methods: Patients that underwent THA/TKA for osteoarthritis with postoperative hemoglobin (Hb) ≤ 8 g/dl were retrospectively identified. We evaluated characteristics and adverse postoperative outcomes of patients not transfused and compared them to those of patients who received postoperative transfusion. Adverse outcomes were 90-day readmission, reoperation, infection, and falls, as well as inpatient cardiovascular events and deaths. Results: One thousand eighty-seven patients meeting inclusion criteria underwent THA and TKA. The 399 patients (36.7%) who did not undergo transfuion were younger (67.4 vs 69.5 years, P = .008), healthier (American Society of Anesthesiologist ≤ 2: 64.2% vs 56%, P = .006), comprised a lower proportion of cardiovascular disease patients (13.8% vs 24.7%, P < .001), a lower proportion of patients with Medicare/Medicare Managed Care (57.2% vs 65.5%, P = .05), received tranexamic acid more frequently (66.4% vs 52.9%, P < .01), had a shorter procedure time (92.7 vs 103.1, P < .01), a lower postoperative drop in Hb (4.0 vs 4.2 g/dl, P = .022), a later drop in Hb (2.6 vs 2.2 days, P = .003), and a shorter length of stay (3.5 vs 4.8, P < .01). TKA patients underwent transfusion more frequently than THA patients (67.5% vs 59%, P = .004). There were no postoperative deaths. Adverse events were similar between the 2 groups. Conclusion: Findings suggest that younger and healthier patients that have lower Hb later during their hospital stay need not undergo transfusion solely based on Hb levels. Routine transfusion triggers can be avoided even in more anemic patients.

Avoiding Femoral Canal Instrumentation in Computer-Assisted Total Knee Arthroplasty With Contemporary Blood Management Had Minimal Differences in Blood Loss and Transfusion Rates Compared to Conventional Techniques.

BACKGROUND: Computer-assisted surgery that does not utilize femoral canal instrumentation is theorized to have less blood loss. However, there is a paucity of data on this, particularly in the era of tranexamic acid use. We sought to analyze the association of computer navigation with total calculated blood loss and transfusion rate in patients undergoing primary total knee arthroplasty (TKA). METHODS: We identified 14,890 patients who underwent unilateral primary TKA at a single institution from 2016 to 2020. Computer-assisted surgery in the form of an accelerometer or robotics was utilized in 4,165 TKAs (28%). Drains were utilized in 4,860 TKAs (32%). We used multivariate logistic regression analysis to determine if computer navigation reduced the rate of blood transfusion and linear regression analysis to determine the impact of computer navigation on blood loss. RESULTS: In total, 542 patients (3.6%) underwent a transfusion. The average change in hemoglobin (Hgb) was 2.1 g/dL (standard deviation [SD] 0.91) and average total calculated blood loss was 310 mL (SD = 154). In a multivariate regression model, computer navigation was not protective of transfusion (odds ratio [OR] 1.04, P = .73). Preoperative Hgb <10 (OR 10.5, P < .0001) and drain use (OR 2.25, P < .0001) were the most significant risk factors for transfusion. In a linear regression model, computer navigation reduced blood loss by 19 mL (SD 2.94, P < .0001) per case. CONCLUSION: In this large retrospective cohort analysis of contemporary TKA patients, computer-assisted surgery that eliminates intramedullary femoral canal instrumentation during primary TKA was not associated with reduced transfusion rates and had minimal differences in overall blood loss.

Blood Management Following Total Joint Arthroplasty in an Aging Population: Can We Do Better?

BACKGROUND: To evaluate the transfusion rates for octogenarians and nonagenarians following total knee and hip arthroplasty (TKA, THA), we compared transfusion rates and associated risk factors among sexagenarians, septuagenarians, octogenarians, and nonagenarians. METHODS: This retrospective cohort study included 13,603 sexagenarians, 9796 septuagenarians, 2706 octogenarians, and 158 nonagenarians that received a primary, unilateral THA or TKA between 2016 and 2020 at a high-volume institution. Using multivariable logistic regression analysis, the study analyzed risk factors for postoperative transfusions including use of tranexamic acid (TXA) and compared preoperative and postoperative hemoglobin (Hgb) levels and the drop in Hgb. RESULTS: Nonagenarians had significantly higher transfusion rates (THA 25.5%, TKA 26.7%) than octogenarians (THA 9.9%, TKA 9.2%), septuagenarians (THA 3.3%, TKA 4.5%), and sexagenarians (THA 1.9%, TKA 2.9%) (P < .01). Significant risk factors for transfusion requirement following THA were American Society of Anesthesiologists level III (odds ratio [OR] 5.3, P < .01) and American Society of Anesthesiologists level IV (OR 8.0, P = .01), nonuse of TXA (intravenous: OR 0.3, P < .01; topical: OR 0.5, P < .01), lower preoperative Hgb levels (OR 0.4, P < .01), longer duration of surgery (OR 1.0, P < .01), and hepatopathy (OR 3.1, P < .01). Significant risk factors following TKA were nonuse of TXA (intravenous: OR 0.3, P < .01; topical: OR 0.5, P < .01; combined: OR 0.2, P < .01), lower preoperative Hgb levels (OR 0.4, P < .01), and longer surgery time (OR 1.0, P < .01). CONCLUSION: The strongest independent risk factors for increased transfusion rates among octogenarians and nonagenarians were lack of TXA application and lower preoperative Hgb levels. Routine TXA application and preoperative patient optimization are recommended to reduce transfusion rates in patients aged 80+.

Perspective of Attending Physicians on the Use of Telemedicine in an Outpatient Arthroplasty Setting During the COVID-19 Pandemic.

Background: During the worldwide COVID-19 pandemic, physicians had to improvise and adapt new ways to provide care to patients. Purposes: The purpose of this study was to assess physicians' sentiments regarding telemedicine and its use in orthopedic practices. Methods: We performed a cross-sectional study of attending orthopedic physicians, the majority of whom integrated telemedicine into their practices from March to October 2020. A survey was sent to 517 physicians who had registered for an orthopedics conference. The survey included questions pertaining to various factors regarding telemedicine and each physician's practice. Results: Of the 517 physicians who received the survey, 328 responded, for a 63.4% response rate. Of the 328 respondents, 84.1% did not use telemedicine in their practice prior to the COVID-19 pandemic. Even during the pandemic, the physicians most commonly responded that less than 5% of their practice was conducted by telemedicine (n = 103, 31.4%). The second most common response was that more than 20% of visits were done via telemedicine (n = 72, 22.0%); 43.0% of physicians noted that they would not use telemedicine technology in their practice after the pandemic, but 59.1% of physicians would be willing to do annual visits by telemedicine. Ability to examine the patient (2.0 ± 1.0) was rated worse, overall, than either the experience using the technology (3.2 ± 1.0) or the capacity to communicate with the patient (3.6 ± 1.0). Conclusions: Our survey of orthopedic surgeons demonstrates that while the use of telemedicine technology was minimal prior to the pandemic, its use was widely adopted during the pandemic. Nearly half of physicians said that they will continue to use telemedicine.

Telemedicine in an Outpatient Arthroplasty Setting During the COVID-19 Pandemic: Early Lessons from New York City.

Background: The early months of the coronavirus disease 19 (COVID-19) pandemic in New York City led to a rapid transition of non-essential in-person health care, including outpatient arthroplasty visits, to a telemedicine context. Questions/Purposes: Based on our initial experiences with telemedicine in an outpatient arthroplasty setting, we sought to determine early lessons learned that may be applicable to other providers adopting or expanding telemedicine services. Methods: A cross-sectional study was performed by surveying all patients undergoing telemedicine visits with 8 arthroplasty surgeons at 1 orthopedic specialty hospital in New York City from April 8 to May 19, 2020. Descriptive statistics were used to analyze demographic data, satisfaction with the telemedicine visit, and positive and negative takeaways. Results: In all, 164 patients completed the survey. The most common reasons for the telemedicine visit were short-term (less than 6 months), postoperative appointment (n = 88; 54%), and new patient consultation (n = 32; 20%). A total of 84 patients (51%) noted a reduction in expenses versus standard outpatient care. Several positive themes emerged from patient feedback, including less anxiety and stress related to traveling (n = 82; 50%), feeling more at ease in a familiar environment (n = 54; 33%), and the ability to assess postoperative home environment (n = 13; 8%). However, patients also expressed concerns about the difficulty addressing symptoms in the absence of an in-person examination (n = 28; 17%), a decreased sense of interpersonal connection with the physician (n = 20; 12%), and technical difficulties (n = 14; 9%). Conclusions: Patients were satisfied with their telemedicine experience during the COVID-19 pandemic; however, we identified several areas amenable to improvement. Further study is warranted.

The Effectiveness of Closed-Incision Negative-Pressure Therapy Versus Silver-Impregnated Dressings in Mitigating Surgical Site Complications in High-Risk Patients After Revision Knee Arthroplasty: The PROMISES Randomized Controlled Trial.

BACKGROUND: Revision total knee arthroplasty (rTKA) is associated with significant risk of wound-related morbidity. The present study aimed to evaluate the 1) efficacy of closed-incision negative-pressure therapy (ciNPT) vs silver-impregnated antimicrobial dressing (AMD) in mitigating postoperative surgical site complications (SSCs), 2) the effect of ciNPT vs AMD on certain postoperative health utilization parameters, and on 3) patient-reported outcomes (PROs) improvement at 90-day postoperative follow-up. METHODS: This multicenter randomized controlled trial was conducted between December 2017 and August 2019. Patients ≥22 years, at high risk for SSC, and receiving rTKA with full exchange and reimplantation of new prosthetic components or open reduction and internal fixation of periprosthetic fractures were screened for inclusion. Eligible patients were randomized to receive a commercially available ciNPT system or a silver-impregnated AMD (n = 147, each) for minimum of 5-day duration. Primary outcome was the 90-day incidence of SSCs with stratification in accordance with revision type (aseptic/septic). Secondary outcomes were the 90-day health care utilization parameters (readmission, reoperation, dressing changes, and visits) and PROs. RESULTS: Of 294 patients randomized (age: 64.9 ± 9.0 years, female: 59.6%), 242 (82.0%) patients completed the study (ciNPT: n = 124; AMD: n = 118). The incidence of 90-day SSCs was lower for the ciNPT cohort (ciNPT: 3.4% vs AMD: 14.3%; odds ratio (OR): 0.22, 95% confidence interval (0.08, 0.59); P = .0013). Readmission rates (3.4% vs 10.2%, OR: 0.30(0.11, 0.86); P = .0208) and mean dressing changes (1.1 ± 0.3 vs 1.3 ± 1.0; P = .0003) were lower with ciNPT. The differences in reoperation rates, number of visits, and PRO improvement between both arms were not statistically significant (P > .05). CONCLUSION: ciNPT is effective in reducing the 90-day postoperative SSCs, readmission, and number of dressing changes after rTKA. Recommending routine implementation would require true-cost analyses.