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

BackgroundWith the increasing popularity of alternative payment models, minorities who use more postacute care resources may face difficulties with access to quality total hip arthroplasty (THA) and total knee arthroplasty (TKA) care. The purpose of this study is to compare differences in perioperative complications and functional outcomes between African American and Caucasian patients undergoing THA and TKA.MethodsWe reviewed a consecutive series of all primary THA and TKA patients at our institution from 2015 to 2018. Demographics, comorbidities, 90-day complications, readmissions, Veterans Rand 12-Item Health Survey (VR-12), Hip disability Osteoarthritis Outcome Score (HOOS), and Knee injury and Osteoarthritis Outcome Scores (KOOS) were compared between African American and Caucasian patients. A multivariate analysis was performed to control for confounding variables.ResultsOf the 5284 patients included in the study, 1041 were African American (24.5%). Although African American patients had lower preoperative HOOS/KOOS (33.5 vs 45.1, P < .001) and mental VR-12 scores (37.8 vs 51.5, P < .001) compared with Caucasian patients, there was no clinical difference at 1 year in HOOS/KOOS (50.2 vs 50.4), mental VR-12 (55.0 vs 52.6), or physical VR-12 scores (39.5 vs 39.8). When controlling for demographics and medical comorbidities, African American race was associated with increased rehabilitation facility discharge (odds ratio, 1.69; P < .001) but no difference in readmissions or complications.ConclusionAlthough African American patients had lower preoperative functional scores, they made improved postoperative gains when compared with Caucasian patients. Although there was no difference in postoperative complications, further studies should assess social causes for the increase in rehabilitation utilization rates in minority patients.     

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

BackgroundConcerns exist that minorities who utilize more resources in an episode-of-care following total hip (THA) and knee arthroplasty (TKA) may face difficulties with access to quality arthroplasty care in bundled payment programs. The purpose of this study is to determine if African American patients undergoing TKA or THA have higher episode-of-care costs compared to Caucasian patients.MethodsWe queried Medicare claims data for a consecutive series of 7310 primary TKA and THA patients at our institution from 2015 to 2018. We compared patient demographics, comorbidities, readmissions, and 90-day episode-of-care costs between African American and Caucasian patients. A multivariate regression analysis was performed to identify the independent effect of race on episode-of-care costs.ResultsCompared to Caucasians, African Americans were younger, but had higher rates of pulmonary disease and diabetes. African American patients had increased rates of discharge to a rehabilitation facility (20% vs 13%, P < .001), with higher subacute rehabilitation ($1909 vs $1284, P < .001), home health ($819 vs $698, P = .022), post-acute care ($5656 vs $4961, P = .008), and overall 90-day episode-of-care costs ($19,457 vs $18,694, P = .001). When controlling for confounding comorbidities, African American race was associated with higher episode-of-care costs of $440 (P < .001).ConclusionAfrican American patients have increased episode-of-care costs following THA and TKA when compared to Caucasian patients, mainly due to increased rates of home health and rehabilitation utilization. Further study is needed to identify social variables that can help reduce post-acute care resources and prevent reduction in access to arthroplasty care in bundled payment models.     

Migration Patterns for Revision Total Knee Arthroplasty in the United States as Reported in the American Joint Replacement Registry

BackgroundRevision total knee arthroplasty (TKA) is associated with a higher complication rate and a greater cost when compared to primary TKA. Based on patient choice, referral, or patient transfers, revision TKAs are often performed in different institutions by different surgeons than the primary TKA. The aim of this study is to evaluate the effect of hospital size, teaching status, and revision indication on the migration patterns of failed primary TKA in patients 65 years of age and older.MethodsAll primary and revision TKAs reported to the American Joint Replacement Registry from January 2012 through March 2020 were included and merged with the Centers for Medicare and Medicaid Services database. Migration was defined as a patient having a primary TKA and revision TKA performed at separate institutions by different surgeons.ResultsIn total, 9167 linked primary and revision TKAs were included in the analysis. Overall migration rates were significantly higher from small (<100 beds; P = .019), non-teaching institutions (P = .002) driven primarily by patients diagnosed with infection. Infection patients had significantly higher migration rates from small (46.8%, P < .001), non-teaching (43.5%, P < .001) institutions, while migration rates for other causes of revision were statistically similar. Most patients migrated to medium or large institutions (84.7%) for revision TKA rather than small institutions (15.3%, P < .001) and to teaching (78.3%) rather than non-teaching institutions (21.7%, P < .001).ConclusionThere is a diagnosis-dependent referral bias that affects the migration rates of infected primary TKA from small non-teaching institutions leading to a flow of more medically complex patients to medium and large teaching institutions for infected revision TKA.     

Topical Vancomycin Powder and Dilute Povidone-Iodine Lavage Reduce the Rate of Early Periprosthetic Joint Infection After Primary Total Knee Arthroplasty

BackgroundVancomycin powder and dilute povidone-iodine lavage (VIP) was introduced to reduce the incidence of periprosthetic joint infection (PJI) in high-risk total knee arthroplasty (TKA) patients. We hypothesize that VIP can reduce the incidence of early PJI in all primary TKA patients, regardless of preoperative risk.MethodsAn infection database of primary TKAs performed before a VIP protocol was implemented (January 2012-December 2013), during a time when only high-risk TKAs received VIP (January 2014-December 2015), and when all TKAs received VIP (January 2016-September 2019) at an urban, university-affiliated, not-for-profit orthopedic hospital was retrospectively reviewed to identify patients with PJI. Criteria used for diagnosis of PJI were the National Healthcare Safety Network and Musculoskeletal Infection Society guidelines.ResultsVIP reduced early primary TKA PJI incidence in both the high-risk and all-risk cohorts compared with the pre-VIP cohort by 44.6% and 56.4%, respectively (1.01% vs 0.56% vs 0.44%, P = .0088). In addition, after introducing VIP to all-risk TKA patients, compared with high-risk TKA patients, the relative risk of PJI dropped an additional 21.4%, but this finding did not reach statistical significance (0.56% vs 0.44%, P = .4212). There were no demographic differences between the 3 VIP PJI cohorts.ConclusionVIP is associated with a reduced early PJI incidence after primary TKA, regardless of preoperative risk. With the literature supporting its safety and cost-effectiveness, VIP is a value-based intervention, but given the nature of this historical cohort study, a multicenter randomized controlled trial is underway to definitively confirm its efficacy.     

Patient and Intraoperative Factors Influencing Satisfaction Two to Five Years After Primary Total Knee Arthroplasty

The purpose of this study was to compare patient demographics and factors recorded at the time of surgery between patients that were either satisfied or dissatisfied with their TKA at mid-term follow-up. From our prospective outcomes database, 989 primary TKAs with complete preoperative and intraoperative data were identified. At mean follow-up of 3.5 years, 94/989 TKAs (9.5%) were not satisfied with their TKA. African American patients were 3.0 times more likely to be dissatisfied than Caucasians (95% CI = 1.5–6.0, P = .003). Patients with less severe degenerative changes were 2.1 times more likely to be dissatisfied (95% CI = 1.3–3.2, P = .001).     

Higher Rate of Early Revision Following Primary Total Knee Arthroplasty in Patients Under Age 55: A Cautionary Tale

BackgroundThere has been an increased number of total knee arthroplasties (TKAs) performed in young and active patients. Although improved materials have decreased the likelihood of early catastrophic wear, concerns remain with the performance and survivorship of TKA implants in this patient population. The purpose this study is to evaluate perioperative complications, patient-reported outcomes, and implant survivorship of TKAs performed in patients under age 55.MethodsWe retrospectively reviewed 4259 primary TKAs performed over a 4-year period. There were 741 TKAs in patients under age 55. The primary outcome of interest was rate of revision at 30 days, 1, 2, and 5-year time points. Secondary outcomes included postoperative transfusion rate, length of stay, rate of deep vein thrombosis/pulmonary embolism, need for manipulation under anesthesia, readmission and reoperation within 30 days, as well as patient-reported outcomes.ResultsThere were 3518 patients over 55 years and 741 patients under 55 years. Overall, 175 patients required revision (4.1%). Patients under 55 years had significantly higher cumulative revision rate at 1 (3.4% vs 1.8%, P < .001), 2 (5.0% vs 2.4%, P < .001), and 5 years (7.3% vs 3.7%, P < .001). Patients under 55 years had a higher rate of early reoperation. Patients over 55 years required more transfusions and suffered a higher rate of early deep vein thrombosis. Patients over 55 years had significantly greater improvements in Patient Reported Outcome Measurement Information System Global 10 Physical scores at 6 months postoperatively compared to patients under 55 years.ConclusionsDespite improvements in TKA implants, young and active patients remained at higher risk of early revision compared to older patients. The data should be used to counsel young prospective TKA patients about the early risk of reoperation and non–wear-related complications.     

The Impact of Arthroplasty Fellowship Training on Total Joint Arthroplasty: Comparison of Peri-Operative Metrics between Fellowship-Trained Surgeons and Non-Fellowship-Trained Surgeons

BackgroundWe sought to identify differences between total joint arthroplasties (TJAs) performed by adult reconstruction fellowship-trained surgeons (FT) than non-fellowship-trained surgeons (NFT).MethodsA single-institution database was utilized to identify patients who underwent elective TJA between 2016 and 2019.ResultsIn total, 16,882 TJAs were identified: 9111 total hip arthroplasties (THAs) and 7771 total knee arthroplasties (TKAs). Patients undergoing THA by FT surgeons were older (63.11 vs 61.84 years, P < .001), more likely to be white, insured by Medicare, and less likely to be active smokers (P < .0001). Both surgical time (90.03 vs 113.1 minutes, P < .0001) and mean length of stay (LOS) (1.85 vs 2.72 days, P < .0001) were significantly shorter for THAs performed by FT surgeons than NFT surgeons. A significantly greater percentage of patients were discharged home after THA by FT surgeons than NFT surgeons (88.7% vs 85.2%, P = .002). FT patients were quicker to mobilize with therapy and required 25% less opioids. TKAs performed by FT surgeons were associated with shorter surgical times (87.4 vs 94.92 minutes, P < .0001), LOS (2.62 vs 2.84 days, P < .0001), and nearly 19% less opioid requirement in the peri-operative period. In addition to higher Activity Measure for Post-Acute Care scores associated with FT surgeons after TKA, a significantly greater percentage of patients were discharged home after TKA by FT surgeons than NFT surgeons (83.97% vs 80.16%, P < .001).ConclusionFor both THA and TKA, patients had significantly shorter surgical times, LOS, and required less opioids when their procedure was performed by FT surgeons compared to NTF surgeons. Patients who had their TJA performed by a FT surgeon achieved higher Activity Measure for Post-Acute Care scores and were discharged home more often than NFT surgeons. In an era of value-based care, more attention should be paid to the patient outcomes and financial implications associated with arthroplasty fellowship training.Level III EvidenceRetrospective Cohort Study.     

Comparison of Modular Conventional and High-Flexion Posterior-Stabilized Total Knee Arthroplasties in the Same Patients at a Mean Follow-Up of 15 Years

BackgroundAs previous studies are limited to short-term clinical data on conventional and high-flexion total knee arthroplasties (TKAs), long-term clinical data on these TKAs remain unclear. Therefore, we evaluated long-term functional outcome, range of knee motion, revision rate, implant survival, and the prevalence of osteolysis after conventional and high-flexion TKAs in the same patients.MethodsThe authors evaluated a cohort of 1206 patients with a mean age of 65.3 ± 7 years (range: 22-70) who underwent bilateral simultaneous sequential TKAs. One knee received a conventional TKA and the other received a high-flexion TKA. The mean duration of follow-up was 15.6 years (range: 14-17).ResultsNo significant differences were found between the 2 groups at the latest follow-up with respect to Knee Society score (93 vs 92 points, P = .765), pain score (45 vs 44 points, P = .641), range of knee motion (125° vs 126°, P = .712), and radiographic and computed tomography scan results. Furthermore, no significant revision rate differences were found between the 2 groups (1.3% for conventional TKA vs 1.6% for high-flexion TKA; P = .137). There was no osteolysis recorded in either group. The rate of survivorship free of implant revision or aseptic loosening was 98.7% (95% CI = 91-100) for conventional TKA and 98.4% (95% CI = 91-100) for high-flexion TKA at 17 years.ConclusionAt the latest follow-up, we were not able to demonstrate any significant difference between conventional and high-flexion TKAs with respect to functional outcome scores, range of knee motion, revision rate, implant survival, and prevalence of osteolysis.     

What Are the Effects of Patient Point of Entry and Medicaid Status on Postoperative Opioid Consumption and Pain Following Primary Total Knee Arthroplasty?

BackgroundTotal knee arthroplasty (TKA) provides excellent results across a variety of pathologies. As greater focus is placed on the opioid epidemic, we sought to determine if patients presenting for TKA via the Medicaid clinic (Medicaid) differed in terms of their opioid requirements compared to patients presenting via private office clinics (non-Medicaid).MethodsA single-institution total joint arthroplasty database was utilized to identify patients who underwent elective TKA between January 2016 and May 2019. Medicaid clinic patients were insured by some form of Medicaid, whereas private office patients had commercial or Medicare insurance. Morphine milligram equivalents (MMEs) and Activity Measure for Post-Acute Care scores were calculated.ResultsA total of 6509 patients were identified: 413 (6.35%) Medicaid and 6096 (93.65%) non-Medicaid. Medicaid patients were younger (63.32 vs 66.21 years, P < .0001), less likely to be of Caucasian race (21.31% vs 56.82%, P < .0001), and more likely to be active smokers (11.14% vs 7.73%, P < .0001). Although surgical time and home discharge rates were similar, Medicaid patients had longer length of stay (2.80 vs 2.46 days, P < .0001). Opioid requirements were higher for Medicaid patients (200.1 vs 132.2 MMEs, P < .0001), paralleling higher pain scores (3.03 vs 2.55, P < .0001). No differences were found in Activity Measure for Post-Acute Care scores (18.47 vs 18.77, P = .1824).ConclusionMedicaid patients tended to be younger, of minority race, and active smokers compared to non-Medicaid patients. Medicaid patients demonstrated worse postoperative pain scores and required 51% greater MMEs immediately following TKA, highlighting the need for preoperative counseling in traditionally at-risk socioeconomic groups.Level of EvidenceIII, Retrospective Observational Analysis.     

Utility and Prognostic Ability of a Diagnostic Injection Before Revision Total Knee Arthroplasty

BackgroundDiagnostic injections are commonly utilized in the workup of painful total knee arthroplasties (TKA), particularly when the diagnosis remains unclear. However, current literature provides limited evidence regarding the utility and prognostic capability of anesthetic injections in this scenario. This study sought to establish the role of diagnostic injections in predicting successful revision TKA.MethodsA retrospective review was conducted on 144 consecutive aseptic revision TKAs receiving diagnostic anesthetic injections. Instability (57.6%) and aseptic loosening (33.3%) comprised most revision etiologies. Patient-reported percentage pain relief after the injection was statistically correlated with KOOS JR, Knee Society Score, UCLA Activity Level, and satisfaction scores.ResultsAbout 74.3% (107/144) of revision TKAs reported >50% pain relief after injection. There were no differences in pain relief based on revision indication (P = .841). Improvement from preoperative activity level was greater in the >50% pain relief group (P = .024). Four-month patient satisfaction did not differ between patients who reported >50% and ≤50% pain relief (67% vs. 66%, P = .130). About 64% of patients who reported >50% pain relief were satisfied at minimum 1-year follow-up, compared with only 47% of those who reported ≤50% pain relief after diagnostic injection (P < .001).ConclusionStudy results show that patients reporting >50% pain relief after diagnostic injection have improvements in activity level and maintain greater satisfaction at minimum 1-year than those reporting ≤50% pain relief. Expectations for improvement after revision TKA should be tempered if diagnostic anesthetic injection yields minimal subjective pain relief.     

Differences in Pain,Opioid Use,and Function Following Unicompartmental Knee Arthroplasty compared to Total Knee Arthroplasty

BackgroundWe sought to determine if immediate postsurgical pain, opioid use, and clinical function differed between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA).MethodsA single-institution database was utilized to identify patients who underwent elective total joint arthroplasty between 2016 and 2019.ResultsIn total, 6616 patients were identified: 98.20% TKA (6497) and 1.80% (119) UKA. UKA patients were younger, had lower body mass index, and more often male than the TKA cohort. Aggregate opioid consumption (75.94 morphine milligram equivalents vs 136.5 morphine milligram equivalents; P < .001) along with the first 24-hour and 48-hour usage was significantly less for UKA as compared to TKA. Similarly, pain scores (1.98 vs 2.58; P < .001) were lower for UKA while Activity Measure for Post-Acute Care mobilization scores were higher (21.02 vs 18.76; P < .001). UKA patients were able to be discharged home on the day of surgery 37% of the time as compared to 2.45% of TKA patients (P < .0001). Notably, when comparing UKA and TKA patients who were discharged home on the day of surgery, no differences regarding pain scores, opioid utilization, or mobilization were observed.ConclusionUKA patients are younger, have lower body mass index and American Society of Anesthesiologists scores, and more often male than TKA patients. UKA patients had significantly shorter length of stay than TKA patients and were discharged home more often than TKA patients, on both the day of surgery and following hospital admission. Most notably, UKA patients reported lower pain scores and were found to require 45% lower opioid medication in the immediate postsurgical period than TKA patients. Surprisingly, UKA and TKA patients discharged on the day of surgery did not differ in terms of pain scores, opioid utilization, or mobilization, suggesting that our rapid rehabilitation UKA protocols can be successfully translated to outpatient TKAs with similar outcomes.Level III EvidenceRetrospective Cohort Study.     

Surgeons Experience Greater Cardiorespiratory Strain and Stress During Total Hip Arthroplasty Than Total Knee Arthroplasty

BackgroundTotal hip arthroplasty (THA) and total knee arthroplasty (TKA) are physically demanding, with a high prevalence of work-related injuries among arthroplasty surgeons. It is unknown whether there are differences in cardiorespiratory output for surgeons while performing THA and TKA. The objective of this study is to characterize whether differences in surgeon physiological response exist while performing primary THA vs TKA.MethodsThis is a prospective cohort study including 3 high-volume, fellowship-trained arthroplasty surgeons who wore a smart garment that recorded cardiorespiratory data on operative days during which they were performing primary conventional TKA and THA. Variables collected included patient body mass index (BMI), operative time (minutes), heart rate, heart rate variability, respiratory rate, minute ventilation, and energy expenditure (calories).ResultsSeventy-six consecutive cases (49 THAs and 27 TKAs) were studied. Patient BMI was similar between the 2 cohorts (P > .05), while operative time was significantly longer in TKAs (60.4 ± 12.0 vs 53.6 ± 11.8; P = .029). During THA, surgeons had a significantly higher heart rate (95.7 ± 9.1 vs 90.2 ± 8.9; P = .012), energy expenditure per minute (4.6 ± 1.23 vs 3.8 ± 1.2; P = .007), and minute ventilation (19.0 ± 3.0 vs 15.5 ± 3.3; P < .001) compared to TKA.ConclusionSurgeons experience significantly higher physiological strain and stress while performing THA. While scheduling THAs and TKAs, surgeons should consider the higher physical demand associated with THAs and ensure adequate personal preparation and sequence of cases.     

A Current Prosthesis With a 1-mm Thickness Increment for Polyethylene Insert Could Result in Fewer Adjustments of Posterior Tibial Slope in Cruciate-Retaining Total Knee Arthroplasty

BackgroundTo compare posterior tibial slope (PTS) and incidence of excessive PTS between cruciate-retaining (CR) total knee arthroplasties (TKAs) with the current prosthesis, providing a 1-mm increment of polyethylene insert thickness, and its predecessor, providing a 2-mm increment.MethodsEach of 154 CR TKAs with Persona (current group) and NexGen (predecessor group) prostheses with a minimum follow-up period of 2 years were retrospectively reviewed. Preoperative demographics, including age, sex, and body mass index, were similar. Factors affecting the flexion gap were matched in terms of preoperative range of motion, mechanical axis, PTS, preoperative and postoperative posterior femoral offset (PFO), and PFO ratio. The PTS was evaluated radiographically. The incidence of excessive PTS (PTS > 10°) and the frequency of intraoperative PTS-increasing procedures were investigated.ResultsThere were no significant differences in preoperative and postoperative range of motion, mechanical axis, PFO, and PFO ratios between the 2 groups. The preoperative PTS was not significantly different, but the postoperative PTS was significantly lower in the current group (4.6° vs 6.2°, P < .001). There was no case of excessive PTS in the current group, but there were 9 cases (5.8%) in the predecessor group (P = .030). The intraoperative PTS-increasing procedure was performed more frequently in the predecessor group (12.3% vs 21.4%, P = .047).ConclusionThe current prosthesis providing a 1-mm increment of polyethylene insert thickness could decrease the PTS and the occurrence of excessive PTS in CR TKA. The target angle for PTS can be decreased in TKA using the current prosthesis in comparison with its predecessor.Level of EvidenceIII.     

Intraosseous Regional Administration of Vancomycin in Primary Total Knee Arthroplasty Does Not Increase the Risk of Vancomycin-Associated Complications

BackgroundPeriprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is a rare but major complication. Owing to an increasing antibiotic resistance in bacteria causing PJI, vancomycin has been investigated as a prophylactic agent. Intraosseous regional administration (IORA) of vancomycin achieves significantly higher local tissue concentrations than systemic administration. There are limited data on IORA of vancomycin with respect to vancomycin-associated complications.MethodsSingle-surgeon retrospective review of primary TKA was performed between January 2015 and May 2019. All patients received 500 mg of IORA of vancomycin after tourniquet inflation and 3 × 1 g intravenous cefazolin in 24 hrs. Preoperative data collected included age, gender, body mass index, American Society of Anesthesiologists (ASA) score, diabetes, and chronic kidney disease (CKD). We documented in-hospital complications and complications requiring readmission within 12 months. Primary outcome measures were the incidence of acute kidney injury (AKI), ‘red man syndrome’ (RMS), and neutropenia. The secondary outcome measure was PJI incidence.ResultsWe identified 631 primary TKAs in 556 patients, of which 331 received IORA. The mean age was 67.7 ± 8.7 years, and 57.8% were women. CKD was prevalent in 17.2% of the cohort. AKI occurred in 25 (3.9%) cases. After controlling for covariates, CKD was the only significant predictor of AKI (odds ratio = 3.035, P = .023). RMS and neutropenia were not observed in this cohort. The 90-day PJI rate was 0%, and the 1-year PJI rate was 0.2%.ConclusionsLow-dose IORA of vancomycin in addition to standard intravenous systemic cefazolin prophylaxis in TKA is safe without significant adverse effects of vancomycin such as AKI, RMS, or neutropenia.     

Comparison of Cruciate-Sacrificing vs Posterior-Stabilized Total Knee Replacement Using a Contemporary Total Knee System

BackgroundThe use of highly conforming polyethylene tibial inserts in cruciate-retaining total knee arthroplasty (TKA) often requires posterior cruciate ligament (PCL) release/sacrifice for balancing (CS TKA). The CS TKA relies on the posterior capsule, collateral ligaments, and articular conformity without a cam or post to achieve stability. Using prospectively collected data we compared clinical outcomes of CS TKA to posterior-stabilized (PS) TKA utilizing a contemporary TKA system.MethodsSixty-nine consecutive CS TKAs were compared to 45 consecutive PS TKAs at 2-year minimum follow-up. CS knees were balanced with the PCL released. Preoperative/postoperative range of motion (ROM), Knee Society Scores (KSS), stair function, and squatting ROM were analyzed.ResultsAt minimum 2-year follow up, CS and PS TKA demonstrated significant improvement in ROM (P < .001), KSS (Pain, P < .001; Function, P < .001), and KSS stair function (P < .001), with no revisions. There was no difference in preoperative to postoperative improvements for passive knee ROM (10° (0°-20°) vs 13° (5°-25°); P = .16), KSS Pain (34 (21-42) vs 38 (24-46); P = .22), KSS Function (35 (30-50) vs 35 (18-50); P = .34), and KSS stair function (10 (10-20) vs 10 (0-20); P = .37) for CS and PS TKA, respectively. CS TKA had higher squatting ROM (P = .02) at minimum 2-year follow-up compared to PS TKA.ConclusionBoth PS and CS TKA provided significant improvement in clinical outcomes, with no differences in passive ROM, KSS, or stair function postoperatively. Our data support that with proper articular conformity and balancing, cruciate-retaining TKA in a PCL-deficient knee (CS TKA) is appropriate. This may be design specific and further prospective randomized studies are needed to corroborate these findings.     

Preoperative Weight Loss and Postoperative Weight Gain Independently Increase Risk for Revision After Primary Total Knee Arthroplasty

BackgroundThe current American Association of Hip and Knee Surgeons (AAHKS) guidelines recommend preoperative weight loss before total knee arthroplasty (TKA) in patients with body mass index (BMI) ≥40 kg/m². However, there is a paucity of evidence on TKA outcomes after preoperative weight loss. This study therefore evaluated predictors of preoperative and postoperative BMI changes and their impact on outcomes after TKA.MethodsThis is a retrospective review of 3058 primary TKAs at an academic institution from 2015 to 2019. BMI was collected on the day of surgery. Preoperative and postoperative BMI at 6 months and 1 year were also obtained. BMI change of ≥5% was considered clinically significant. Mean follow-up was 3.2 years. Patient demographics, acute postoperative outcomes, and all-cause revisions were compared between patients who gained, lost, or maintained weight using univariate and multivariable analyses.ResultsPreoperative weight loss was predictive of postoperative weight gain (P < .001), and preoperative weight gain was predictive of postoperative weight loss (P < .001). Cox regression analysis revealed that ≥5% BMI loss preoperatively increased risk for all-cause revisions (P = .030), while ≥5% BMI gain postoperatively increased risk for prosthetic joint infections (P = .016). Patients who lost significant weight both before and after surgery had the highest risk for all-cause revisions (P = .022).ConclusionWeight gain postoperatively was associated with inferior outcomes. Significant weight loss before surgery led to a “rebound” in weight gain, and independently increased risk for all-cause revision. Therefore, current recommendations for weight loss before TKA in morbidly obese patients should be re-evaluated.     

Central Sensitization Is a Risk Factor for Persistent Postoperative Pain and Dissatisfaction in Patients Undergoing Revision Total Knee Arthroplasty

BackgroundThe objective of this study is to investigate whether central sensitization (CS) was associated with patient dissatisfaction after revision total knee arthroplasty (TKA).MethodsBetween 2012 and 2016, 68 cases (68 patients) of revision TKA performed by a single surgeon were included in this study with a minimum follow-up of 2 years. Patients were categorized into 2 groups by 40-point preoperative Central Sensitization Inventory (CSI) scores. The control group consisted of 48 patients (48 knees) with CSI scores of less than 40 points, while the CS group consisted of 20 patients (20 knees) with CSI scores of 40 points or more. Clinical outcomes were evaluated using an 11-point visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index scores. Patient satisfaction was evaluated using the satisfaction items of the new Knee Society Scores, where scores ≥20 indicated satisfaction.ResultsHigher preoperative pain VAS scores in the CS group were maintained 3, 6, 12, and 24 months postoperatively (all P < .05). The CS group showed significantly worse pain, function subscores, and total scores of the Western Ontario and McMaster Universities Osteoarthritis Index preoperatively and at 2 years postoperatively. Forty-four (91.7%) patients in the control group and 3 (15.0%) patients in the CS group were satisfied with their revision TKAs (P < .001). Multivariate logistic regression analysis demonstrated that the odds of dissatisfaction after revision TKAs were increased 39.081 times (95% confidence interval 6.926-220.504, P < .001) in patients with CSI scores ≥40. Higher VAS intensity 2 years postoperatively also predicted dissatisfaction following revision TKA (odds ratio 1.864, 95% confidence interval 1.086-3.199, P = .024).ConclusionCS is a risk factor for persistent postoperative pain and dissatisfaction in patients undergoing revision TKAs.Level of EvidenceIII.     

Major National Shifts to Outpatient Total Knee Arthroplasties in the United States: A 10-Year Trends Analysis of Procedure Volumes,Complications, and Healthcare Utilizations (2010 to 2020)

BackgroundThe removal of total knee arthroplasty (TKA) from inpatient-only lists accelerated changes in orthopaedic surgical practices across the United States. This study aimed to (1) quantify the annual volume of inpatient/outpatient primary TKAs; (2) compare patient characteristics before/after the year 2018; and (3) compare annual trends in 30-day readmissions, 30-day complications, and healthcare utilization parameters for inpatient/outpatient TKAs.MethodsThe National Surgical Quality Improvement Program was reviewed (January 2010 to December 2020) for patients who underwent primary TKA (n = 470,456). The primary outcome was annual volumes of inpatient/outpatient TKA. Secondary outcomes included 30-day readmissions, 30-day reoperations, and 30-day major/minor complications. Demographic characteristics and healthcare utilization parameters (hospital lengths of stay and discharge dispositions) were compared between cohorts via Chi-square goodness-of-fit tests.ResultsOverall, 89% had inpatient TKA (n = 416,972) and 11% had outpatient TKA (n = 53,854). Between 2017 and 2020, annual volumes of outpatient TKA increased by 1,925 (1,019 to 20,633), while inpatient TKA decreased by 53% (61,874 to 29,280). Patients who had outpatient TKA after 2018 were older (P < .001), predominantly males (P < .001), more commonly White (P < .001), and had a greater proportion of American Society of Anesthesiologists class III (P < .001). The inpatient cohort had higher rates of 30-day readmissions, reoperations, and complications. Average length of stay and nonhome discharges decreased for both cohorts.ConclusionOutpatient TKA increased 20-fold at NSQIP hospitals. The changes in comorbidity profiles and the increase in volumes of outpatient TKA were not associated with a rise in cumulative 30-day readmissions and complications. Further research and policy endeavors should focus on identifying patients who still require or benefit from inpatient TKA.     

Posterior-Stabilized TKA in Patients With Severe Genu Recurvatum Achieves Good Clinical and Radiological Results at 5-year Minimum Follow-Up: A Case-Controlled Study

BackgroundGenu recurvatum is a rare knee deformity. Total knee arthroplasty (TKA) in severe preoperative recurvatum requires surgical adjustments. Few studies have assessed the clinical and radiological results of TKA in recurvatum. The aim was to compare the clinical and radiological outcomes, complications, and revision rates after posterior-stabilized TKA in severe recurvatum with those without recurvatum.MethodsBetween 1987 and 2015, 32 primary posterior-stabilized TKA were performed with a preoperative genu recurvatum greater than 10° and minimum follow-up of 60 months. In severe genu recurvatum, the extension gap needs to be decreased compared with flexion gap. To achieve this, the distal femoral cut is distalized, whereas the posterior femoral and tibial cuts are performed as usual. They were compared with 64 matched posterior-stabilized TKAs without recurvatum. The demographic data were similar between groups. The clinical and radiological outcomes, complications, and revision rates were assessed at the last follow-up.ResultsAt a mean follow-up of 7.4 years ± 1.9, there was no significant difference in International Knee Score functional score (77.5 vs. 73.4; P = .50) and knee score (86.6 vs. 89.5; P = .37) between the recurvatum group and the control group, respectively. 6 patients had a postoperative recurvatum equal or superior to 10° in the recurvatum group (18.8%). There was no difference between both groups in radiological outcomes, complication, or revision rates. No instability was found in the recurvatum group.ConclusionPosterior-stabilized TKA with controlled distalization of the femoral component in the setting of severe preoperative genu recurvatum achieves good clinical and radiological outcomes at a minimum follow-up of 5 years and similar to TKA without preoperative recurvatum.Level of EvidenceIII.     

The Effect of Polyethylene Liner Thickness on Patient Outcomes and Failure After Primary Total Knee Arthroplasty

BackgroundThe effect of using thicker liners in primary total knee arthroplasty (TKA) on functional outcomes and aseptic failure rates remains largely unknown. As such, we devised a multicenter study to assess both the clinical outcomes and survivorship of thick vs thin liners after primary TKA.MethodsA search of our institutional databases was performed for patients having undergone bilateral (simultaneous or staged) primary TKA with similar preoperative and surgical characteristics between both sides. Two cohorts were created: thick liners and thin liners. Outcomes collected were as follows: change in Knee Society Score (ΔKSS), change in range of motion, and aseptic revision. Ad hoc power analysis was performed for ΔKSS (⍺ = 0.05; power = 80%). Differences between cohorts were assessed.ResultsAbout 195 TKAs were identified for each cohort. ΔKSS and change in range of motion in the thin vs thick cohorts were similar: 51.4 vs 51.6 (P = .86) and 11.1° vs 10.0° (P = .66), respectively. No difference in aseptic revision rates were observed between thin and thick cohorts: all cause (4.1%, 3.1%; P = .59), aseptic loosening (0.5%, 0.5%; P = 1.0), instability (0.5%, 0.5%; P = 1.0), all-cause revision for stiffness (3.1%, 2.1%; P = .52), manipulation under anesthesia (2.1%, 2.1%; P = 1.0), and liner exchange (0.5%, 0%; P = .32).ConclusionThe results of this study suggest that both rates of revision surgery and clinical outcomes are similar for TKAs performed with thick and thin liners. Preoperative factors are likely to play an important role in liner thickness selection, and emphasis should be placed on ensuring sound surgical technique.