Effect of Price Capitation on Implant Selection for Primary Total Hip and Knee Arthroplasty

While price capitation strategies may help to control total hip (THA) and knee arthroplasty (TKA) implant costs, its effect on premium implant selection is unclear. Primary THA and TKA cases 6 months before and after capitated pricing implementation were retrospectively identified. After exclusions, 716 THA and 981 TKA from a large academic hospital and 2 midsize private practice community hospitals were reviewed. Academic hospital surgeons increased premium THA implant usage (66.5% to 70.6%; P = 0.28), while community surgeons selected fewer premium implants (36.4%) compared to academic surgeons, with no practice change (P = 0.95). Conversely, premium TKA implant usage significantly increased (73.4% to 89.4%; P < 0.001) for academic surgeons. Community surgeons used premium TKA implants at greater rates in both periods, with all cases having ≥ 1 premium criterion.     

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.     

Drivers of the Variation in Prosthetic Implant Purchase Prices for Total Knee and Total Hip Arthroplasties

Background

Previous studies have documented wide variation in health care spending and prices; however, the causes for the variation in supply purchase prices across providers are not well understood. The purpose of this study was to determine the drivers of variation in prosthetic implant purchase prices for primary total knee and hip arthroplasties (TKA and THA, respectively) across providers.

From Winners to Losers: The Methodology of Bundled Payments for Care Improvement Advanced Disincentivizes Participation in Bundled Payment Programs

BackgroundThe Bundled Payments for Care Improvement (BPCI) initiative improved quality and reduced costs following total hip (THA) and knee arthroplasty (TKA). In October 2018, the BPCI-Advanced program was implemented. The purpose of this study is to compare the quality metrics and performance between our institution’s participation in the BPCI program with the BPCI-Advanced initiative.MethodsWe reviewed a consecutive series of Medicare primary THA and TKA patients. Demographics, medical comorbidities, discharge disposition, readmission, and complication rates were compared between BPCI and BPCI-Advanced groups. Medicare claims data were used to compare episode-of-care costs, target price, and margin per patient between the cohorts.ResultsCompared to BPCI patients (n = 9222), BPCI-Advanced patients (n = 2430) had lower rates of readmission (5.8% vs 3.8%, P = .001) and higher rate of discharge to home (72% vs 78%, P < .001) with similar rates of complications (4% vs 4%, P = .216). Medical comorbidities were similar between groups. BPCI-Advanced patients had higher episode-of-care costs ($22,044 vs $18,440, P < .001) and a higher mean target price ($21,154 vs $20,277, P < .001). BPCI-Advanced patients had a reduced per-patient margin compared to BPCI ($890 loss vs $1459 gain, P < .001), resulting in a $2,138,670 loss in the first three-quarters of program participation.ConclusionDespite marked improvements in quality metrics, our institution suffered a substantial loss through BPCI-Advanced secondary to methodological changes within the program, such as the exclusion of outpatient TKAs, facility-specific target pricing, and the elimination of different risk tracks for institutions. Medicare should consider adjustments to this program to keep surgeons participating in alternative payment models.     

Does Unicompartmental Knee Replacement Offer Improved Clinical Advantages Over Total Knee Replacement in the Treatment of Isolated Lateral Osteoarthritis? A Matched Cohort Analysis From an Independent Center

BackgroundThe purpose of this study is to compare the functional and radiographic results, perioperative complications, satisfaction rate, and mid-term survivorship after unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) for the treatment of lateral compartmental knee osteoarthritis (LCKO).MethodsBetween March 2007 and September 2017, we identified 35 patients with primary TKAs and 121 patients with lateral UKAs (LUKAs) for LCKO with a minimum follow-up of 2 years (mean 5.3 years, range 2-12.4). The matched variables were age, gender, operation side, body mass index, American Society of Anesthesiologist grade, initial diagnosis, osteoarthritis grade in lateral compartment, and follow-up time. All patients were assessed using the Oxford Knee Score, Hospital for Special Surgery score, range of motion, length of hospital stay, satisfaction, and complications. Survivorship of UKA and TKA implants was also compared.ResultsAt last follow-up, LUKA had a significantly better postoperative Oxford Knee Score, Hospital for Special Surgery score, range of motion, shorter length of hospital time, and higher satisfaction rate than matched TKA group. There were significant differences regarding patellar tendon injury (P = .043), superficial wound infection (P = .028), patellar snapping or impingement (P = .047), and stiffness (P < .001). Five-year survivorships free from revision were similar in both groups (99.2% vs 97.1%, P = .347).ConclusionLUKA for LCKO demonstrated more favorable 5-year results in comparison with TKA. Furthermore, LUKA achieved comparable mid-term survivorship and was less likely to suffer from wound infection and knee stiffness, although not overall surgical complications.     

Surgeon Reimbursement Unchanged as Hospital Charges and Reimbursements Increase for Total Joint Arthroplasty

BackgroundDespite increasing demands on physicians and hospitals to increase value and reduce unnecessary costs, reimbursement for healthcare services has been under downward pressure for several years. This study aimed to analyze the trend in hospital charges and payments relative to corresponding surgeon charges and payments in a Medicare population for total hip (THA) and knee arthroplasty (TKA).MethodsThe 5% Medicare sample database was used to capture hospital and surgeon charges and payments related to 56,228 patients who underwent primary THA and 117,698 patients who underwent primary TKA between 2005 and 2014. Two values were calculated: (1) the charge multiplier (CM), the ratio of hospital to surgeon charges and (2) the payment multiplier (PM), the ratio of hospital to surgeon payments. Year-to-year variation and regional trends in patient demographics, Charlson Comorbidity Index, length of stay (LOS), CM, and PM were evaluated.ResultsHospital charges were significantly higher than surgeon charges and increased substantially for both THA (CM increased from 8.7 to 11.5, P < .0001) and TKA (CM increased from 7.9 to 11.4, P < .0001). PM followed a similar trend, increasing for both THA and TKA (P < .0001). LOS decreased significantly for both THA and TKA (P < .0001), while Charlson Comorbidity Index remained stable. Both CM (r² = 0.84 THA, 0.90 TKA) and PM (r² = 0.75 THA, 0.84 TKA) were strongly negatively associated with LOS.ConclusionHospital charges and payments relative to surgeon charges and payments have increased substantially for THA and TKA despite stable patient complexity and decreasing LOS.     

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.     

What Factors Affect Whether Patients Return to the Same Surgeon to Replace the Contralateral Joint? A Study of Over 200,000 Patients

BackgroundPatients with hip and knee arthritis often undergo bilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) in a staged or simultaneous fashion. However, when staged, the incidence and factors associated with having both procedures performed by the same surgeon or different surgeon are not well studied.MethodsAll patients undergoing nonsimultaneous bilateral THA or TKA for osteoarthritis were abstracted from the 2010 to 2020 PearlDiver Mariner administrative database. The National Provider Identifier number was used to determine whether the same surgeon performed both surgeries. Demographics, comorbidities, and 90-day complications after the first joint replacement were assessed as possible independent predictors of utilizing a different surgeon for the contralateral joint.ResultsOf 87,593 staged bilateral THAs, the same surgeon performed 40,707 (46.5%) arthroplasties. Of 147,938 staged bilateral TKAs, the same surgeon performed 77,072 (52.1%) arthroplasties. Notably, older cohorts of patients had independent, stepwise, and significantly greater odds of changing surgeons for the contralateral THA and TKA. Those patients who were insured by Medicare and Medicaid had significantly lower odds of changing surgeons. For both THA and TKA, surgical and implant-related adverse events (surgical site infection/periprosthetic joint infection, periprosthetic fracture, dislocation, manipulation) carried the greatest odds of undergoing the contralateral replacement with a different surgeon.ConclusionPatients covered by Medicaid and sicker patients were significancy less likely to switch surgeons for their contralateral THA or TKA. Additionally, patients experiencing a surgery-related adverse event within 90 days of their first THA or TKA had significantly, increased odds of switching surgeons for their subsequent TJA.     

Racial Disparities in Rates of Revision and use of Modern Features in Total Knee Arthroplasty,a National Registry Study

BackgroundThe purpose of our study was to investigate the association of race and ethnicity with rates of modern implant use and postoperative outcomes in total knee arthroplasty (TKA) using the American Academy of Orthopaedic Surgeons American Joint Replacement Registry.MethodsAdult TKAs from 2012 to 2020 were queried from the American Joint Replacement Registry. A total of 1,121,457 patients were available for analysis for surgical features and 1,068,210 patients for analysis of outcomes. Mixed-effects multivariable logistic regression models were used to examine the association of race with each individual surgical feature (unicompartmental knee arthroplasty (UKA) and robotic-assisted TKA (RA-TKA)) and 30- and 90-day readmission. A proportional subdistribution hazard model was used to model the risk of revision TKA.ResultsOn multivariate analyses, compared to White patients, Black (odds ratio (OR): 0.52 P < .0001), Hispanic (OR 0.75 P < .001), and Native American (OR: 0.69 P = .0011) patients had lower rates of UKA, while only Black patients had lower rates of RA-TKA (OR = 0.76 P < .001). White (hazard ratio (HR) = 0.8, P < .001), Asian (HR = 0.51, P < .001), and Hispanic-White (HR = 0.73, P = .001) patients had a lower risk of revision TKA than Black patients. Asian patients had a lower revision risk than White (HR = 0.64, P < .001) and Hispanic-White (HR = 0.69, P = .011) patients. No significant differences existed between groups for 30- or 90-day readmissions.ConclusionBlack, Hispanic, and Native American patients had lower rates of UKA compared to White patients, while Black patients had lower rates of RA-TKA compared to White, Asian, and Hispanic patients. Black patients also had higher rates of revision TKA than other races.     

Staging Bilateral Total Knee Arthroplasties Reduces Alignment Outliers

BackgroundPatients frequently present with bilateral symptomatic knee osteoarthritis and request simultaneous total knee arthroplasties (TKAs). Technical differences between simultaneous and staged TKAs could affect clinical and radiographic outcomes. We hypothesized that staged TKAs would have fewer mechanical alignment outliers than simultaneous TKAs.MethodsWe reviewed 87 simultaneous and 72 staged TKAs with at least 2 years of follow-up. Radiographic assessment was done using standing long leg and lateral radiographs of the knee. Coronal and sagittal measurements were performed by 4 blinded observers on 2 separate occasions with an intraobserver agreement of 0.95 and interobserver of 0.92.ResultsThe first simultaneous knee had no difference in the probability of establishing the mechanical axis outside 3° of neutral (45%) compared to the first staged knee (54%, P = .337). However, the second simultaneous knee (49%) was more likely to establish the axis outside mechanical neutral compared to the second staged knee (28%; odds ratio 2.54, confidence interval 1.31-4.94, P = .006). There was an increased risk of deep venous thrombosis with staged TKA (odds ratio 2.96, confidence interval 1.28-6.84, P = .011), but other perioperative complication rates were not significantly different. There were no clinically significant differences in range of motion or Knee Society Score.ConclusionThere is a significantly increased risk of establishing the second knee outside mechanical neutral during a simultaneous TKA compared to staged bilateral TKAs, possibly related to a number of surgeon-related and system-related factors. The impact on clinical outcomes and radiographic loosening may become significant in long-term follow-up.     

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.     

Utilization of Debridement,Antibiotics, and Implant Retention for Infection After Total Joint Arthroplasty Over a Decade in the United States

BackgroundReported clinical outcomes have varied for debridement, antibiotics, and implant retention (DAIR) and little is known regarding trends in utilization. We sought to evaluate the rate of DAIR utilization for total knee arthroplasty (TKA) and total hip arthroplasty (THA) periprosthetic joint infection (PJI) over a decade and clinical factors associated with these trends.MethodsA retrospective study of primary TKAs and THAs was performed using Medicare data from 2005 to 2014 using the PearlDiver database platform. Current Procedural Technology and International Classification of Diseases Ninth Edition codes identified patients who underwent a surgical revision for PJI, whether revision was a DAIR, as well as associated clinical factors including timing from index arthroplasty.ResultsThe proportion of revision TKAs and THAs performed using DAIR was 27% and 12% across all years, respectively. This proportion varied by year for TKAs and THAs with a linear trend toward increasing relative use of DAIR estimated at 1.4% and 0.9% per year (P < .001; P < .001). DAIR for TKA and THA performed within 90 days increased at a faster rate, 3.4% and 2.1% per year (P < .001; P < .001). Trends over time in TKA DAIRs showed an association with Elixhauser Comorbidity Index (ECI), 0-5 group increasing at 2.0% per year (P = .03) and patients >85 years (P = .04).ConclusionThe proportion of revision arthroplasty cases for PJI managed with DAIR has been increasing over time in the United States, with the most substantial increase seen <90 days from index arthroplasty. Age, gender, and ECI had a minimal association with this trend, except in the TKA population >85 years and in those with a very low ECI score.     

Manipulation Under Anesthesia is Safe After Cementless Total Knee Arthroplasty: A Multicenter Study

BackgroundCementless total knee arthroplasty (TKA) is thought to facilitate durable, biological fixation between the bone and implant. However, the 4-12 weeks required for osseointegration coincides with the optimal timeframe to perform a manipulation under anesthesia (MUA) if a patient develops postoperative stiffness. This study aims to determine the impact of early MUA on cementless fixation by comparing functional outcomes and survivorship of cementless and cemented TKAs.MethodsA consecutive series of patients who underwent MUA for postoperative stiffness within 90 days of primary, unilateral TKA at 2 academic institutions between 2014 and 2018 were identified. Cases involving extensive hardware removal were excluded. Cementless TKAs undergoing MUA (n = 100) were propensity matched 1:1 to cemented TKAs undergoing MUA (n = 100) using age, gender, body mass index, and year of surgery. Both groups had comparable baseline Knee Injury and Osteoarthritis Outcome Scores (KOOS), Short Form (SF)-12 Physical, and SF-12 Mental scores. MUA-related complications as well as postoperative KOOS and SF-12 scores were compared.ResultsMUA-related complications were equivalently low in both groups (P = .324), with only 1 patella component dissociation in the cementless group. No tibial or femoral components acutely loosened in the perioperative period. Postoperative KOOS (P = .101) and SF-12 Mental scores (P = .380) were similar between groups. Six-year survivorship free from any revision after MUA was 98.0% in both groups (P = 1.000).ConclusionEarly postoperative MUA after cementless TKA was not associated with increased MUA-related complications or worse patient-reported outcomes compared to cemented TKA. Short-term survivorship was also comparable, suggesting high durability of the bone-implant interface.     

Periprosthetic Tissue Reaction Independent of LTT Result and Implanted Materials in Total Knee Arthroplasty

BackgroundAn allergic reaction may rarely cause a painful or stiff total knee arthroplasty (TKA). However, no consensus diagnostic criteria for TKA immune failure exist. Lymphocyte transformation testing (LTT) measures immune sensitivity to various materials, but its role in diagnosing an allergic reaction to a TKA has not been established. This study compares TKA periprosthetic tissues in a) LTT-positive versus -negative patients and b) patients with conventional CoCrNi versus hypoallergenic implants.MethodsPeriprosthetic tissues from 26 revision cases of well-fixed, aseptic, but painful or stiff TKAs were analyzed. Twelve patients LTT positive for nickel (Ni) were matched as a cohort to 6 LTT-negative patients. In 4 patients LTT positive for Ni, tissue from first revision of CoCrNi implants was compared with tissue from subsequent revision of hypoallergenic implants. Histology was evaluated using the aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) score.ResultsNo correlation was found between LTT and any ALVAL score component. The mean total ALVAL score was 3.8 ± 1.5 for LTT-negative patients and 3.3 ± 1.2 for LTT-positive patients (P = .44). The mean total ALVAL score at revision of CoCrNi implants was 3.0 ± 1.8 compared with 5.8 ± 0.5 at rerevision of hypoallergenic implants (P = .053).ConclusionPeriprosthetic TKA tissue reactions were indistinguishable between LTT-positive and -negative patients. LTT does not predict the periprosthetic tissue response. ALVAL scores of hypoallergenic revision implant tissue trended higher than primary CoCrNi implant tissue. A positive LTT may not indicate that a periprosthetic immune reaction is the cause of pain and stiffness after TKA.Level of Evidence3, retrospective 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.     

Does the Use of Intraoperative Pressure Sensors for Knee Balancing in Total Knee Arthroplasty Improve Clinical Outcomes? A Comparative Study With a Minimum Two-Year Follow-Up

BackgroundIt is undetermined whether using sensors for knee balancing in total knee arthroplasty (TKA) improves patient outcomes. The purpose of this study was to compare clinical outcomes of sensor balance (SB) with manual balance (MB) TKA with a minimum two-year follow-up.MethodsA consecutive series of 207 MB TKAs was compared with 222 SB TKAs between April 2014 and April 2017. A single surgeon performed all surgeries, using the same prosthesis. The primary end point was the aggregated mean change in four subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS₄) between preoperative and two-year time points. Secondary outcomes included mean differences between groups in all five KOOS subscales, proportions of knee balancing procedures, and rates of reoperations including revisions and manipulations for stiffness.ResultsThe mean changes in the KOOS₄ aggregated means for MB TKA (42.4; standard deviation, 29.1) and SB TKA (41.5; standard deviation, 25.0) were not significantly different (mean difference, 0.9; 95% confidence interval: –2.6 to 4.4, P = .62). There were significantly more balancing procedures in the SB group (55.9% versus 16.9%; P < .01). There were no significant differences in the number of reoperations (1.4% SB versus 1.4% MB; P = .71) or manipulations for stiffness (3.7% SB versus 4.4% MB; P = .69).ConclusionThe use of sensors in TKA to achieve knee balance did not result in improved clinical outcomes, despite significantly increasing the number of surgical interventions required to achieve a balanced knee. Sensors did not alter the rates of revision surgery or requirements for manipulation. It remains to be determined whether precise soft-tissue balancing improves prosthetic survivorship and joint biomechanics.     

Residents’ Learning Curve of Total Knee Arthroplasty Based on Radiological Outcome Parameters: A Retrospective Comparative Study

BackgroundThis study aimed to plot the impact of a learning curve for a resident’s first 103 total knee arthroplasties (TKAs) based on radiological deviations and incision to closure time (ICT), and to compare it to 103 matched TKAs performed by a senior surgeon.MethodsThis is a retrospective comparative study comprising a total of 206 TKAs and evaluated the results based on radiographic outcome and ICT. Radiological evaluation was performed according to a predefined implemented radiological grading system (RGS). t-Tests compared ICT and RGS; data of mechanical axis were observed with Man-Whitey U-tests and Wilcoxon signed-rank-tests.ResultsThe study included 206 patients (mean age 73 years, mean body mass index of 30). Determining all the deviation points (DP) with the RGS, the deviation ratio for resident vs senior surgeon was 0.96:0.5 DP (P = .0002). The learning curve based on DP showed a decrease over time with statistical significance in the first (26 DP, P = .0001), second (21 DP, P = .0059), and fourth (20 DP, P = .0187) quintiles of implanted cases. The ICT of the resident showed a decrease within the quintiles from 79.45 minutes (first quintile) to 65.17 minutes (fifth quintile), for an improvement of 14.28 minutes. When the quintiles are viewed in relation to the mean operation time of the senior surgeon (mean ICT 66.04 minutes), the mean values of the first and the second quintiles remain statistically significant.ConclusionSupervised TKA showed statistical significance in the learning curves according to deviations documented with a predefined radiological outcome assessment system as well as to ICTs.Level of EvidenceLevel III, retrospective comparative study;     

Weight Gain After Primary Total Knee Arthroplasty Is Associated With Accelerated Time to Revision for Aseptic Loosening

BackgroundObesity is a major health problem worldwide and is associated with complications after total knee arthroplasty (TKA). It remains unknown whether a change in body mass index (BMI) after primary TKA affects the reasons for revision TKA or the time to revision TKA.MethodsA total of 160 primary TKAs referred to an academic tertiary center for revision TKA were retrospectively stratified according to change in BMI from the time of their primary TKA to revision TKA. The association between change in BMI and time to revision was also analyzed according to indication for revision of TKA using Pearson's chi-square test.ResultsThe mean change in BMI from primary to revision TKA was 0.82 ± 3.5 kg/m². Maintaining a stable weight after primary TKA was protective against late revision TKA for any reason (P = .004). Patients who failed to reduce their BMI were revised for aseptic loosening earlier, at less than 5 years (P = .020), whereas those who reduced their BMI were revised later, at over 10 years (P = .004).ConclusionMaintaining weight after primary TKA is protective against later revision TKA for any reason but failure to reduce weight after primary TKA is a risk factor for early revision TKA for aseptic loosening and osteolysis. Orthopedic surgeons should recommend against weight gain after primary TKA to reduce the risk of an earlier revision TKA in the event that a revision TKA is indicated.     

Does Metabolic Syndrome Impact the Risk of Reoperation,Revision, or Complication After Primary Total Knee Arthroplasty?

BackgroundMetabolic syndrome (MetS) is an increasingly frequent condition characterized by insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study evaluated implant survivorship, complications, and clinical outcomes of primary TKAs performed in patients who have MetS.MethodsUtilizing our institutional total joint registry, 2,063 primary TKAs were performed in patients with a diagnosis of MetS according to the World Health Organization criteria. MetS patients were matched 1:1 based on age, sex, and surgical year to those who did not have the condition. The World Health Organization’s body mass index (BMI) classification was utilized to evaluate the effect of obesity within MetS patients. Kaplan–Meier methods were utilized to determine implant survivorship. Clinical outcomes were assessed with Knee Society scores. The mean follow-up was 5 years.ResultsMetS and non-MetS patients did not have significant differences in 5-year implant survivorship free from any reoperation (P = .7), any revision (P = .2), and reoperation for periprosthetic joint infection (PJI; P = .2). When stratifying, patients with MetS and BMI >40 had significantly decreased 5-year survivorship free from any revision (95 versus 98%, respectively; hazard ratio = 2.1, P = .005) and reoperation for PJI (97 versus 99%, respectively; hazard ratio = 2.2, P = .02). Both MetS and non-MetS groups experienced significant improvements in Knee Society Scores (77 versus 78, respectively; P < .001) that were not significantly different (P = .3).ConclusionMetS did not significantly increase the risk of any reoperation after TKA; however, MetS patients with BMI >40 had a two-fold risk of any revision and reoperation for PJI. These results suggest that obesity is an important condition within MetS criteria and remains an independent risk factor.Level of EvidenceLevel 3, Case-control study.     

The Importance of Oral History: Does Dental Implant Placement or Caries One Year Before or After Primary Total Knee Arthroplasty Increase Medical Complications and Periprosthetic Joint Infections?

BackgroundConsensus regarding prior dental problems on the outcomes of total knee arthroplasty (TKA) patients is lacking. Therefore, our objectives were to determine the association of dental caries or dental implant placement in TKA patients on the following: (1) medical complications; (2) health care utilization (lengths of stay and readmissions); (3) implant-related complications; and (4) expenditures.MethodsA retrospective query was performed using an administrative claims database for 3 patient cohorts undergoing primary TKA from 2010 to 2020. Patients who had a history of dental caries or implant placement 1 year prior to TKA (n = 1,466) and 1 year after TKA (n = 1,127) were case-matched to patients who did not have a dental history by age and comorbidities. Outcomes included 90-day complications, health care utilization parameters, 2-year implant complications, and expenditures. Logistic regression models computed odds ratios (OR) of complications and readmissions. P values less than 0.005 were significant.ResultsPatients who had a dental implant placement prior to TKA had higher frequency of complications (20.05 versus 14.01%; OR: 1.53, P < .0001), including myocardial infarctions (2.52 versus 1.23%; OR: 2.08, P = .0002) and pneumonia (2.52 versus 1.24%; OR: 2.06, P = .0002). Lengths of stay (3.28 versus 2.98 days; P = .255), readmission rates (4.71 versus 4.28%; P = .470), and implant-related complications including periprosthetic joint infections (3.14 versus 2.63%; OR: 1.20, P = .279) were similar between patients lacking dental history. Expenditures were higher in patients who had a postoperative and preoperative dental history ($19,252 versus $19,363 versus 17,980; P < .001).ConclusionDental caries or implant placement may reflect overall worse medical condition resulting in more complications and higher costs after TKA. Dental history screening preoperatively may assist arthroplasty surgeons in minimizing complications.