Concurrent Hardware Removal is Associated With Increased Odds of Infection Following Conversion Total Knee Arthroplasty

BackgroundThe optimal timing of removal of periarticular implants prior to conversion total knee arthroplasty (TKA) remains to be determined. The purpose of this study was to compare infection rates in conversion TKA when hardware removal was performed in either a staged or concurrent manner.MethodsWe performed a retrospective study using a national insurance claims database of patients who underwent removal of hardware on the same day or within 1 year before their TKA. A total of 16,099 patients met the criteria. After matching, both final cohorts consisted of 4,502 patients. The 90-day and 1-year rates of prosthetic joint infection were calculated.ResultsThe rates of infection were 1.64% and 3.00% in the staged group and 2.62% and 3.95% in the concurrent group at 90 days and 1 year postoperatively, respectively (P = .001, P = .01). Logistic regression analyses demonstrated that patients who had hardware removal greater than 3 months prior to TKA had significantly lower odds of infection at 1-year postop (Odds Ratio 0.61 95% Confidence Interval 0.45-0.84; P = .003).ConclusionRemoval of hardware performed concurrently or within 3 months of a TKA is associated with increased odds of prosthetic joint infection at 1 year postoperatively. Surgeons should consider removing periarticular hardware prior to TKA when possible.     

Increased Revisions in Conversion Total Knee Arthroplasty After Periarticular Open Reduction Internal Fixation Compared With Primary Total Knee Arthroplasty: A Matched Cohort Analysis

BackgroundPrior studies on conversion total knee arthroplasty (cTKA) have reported increased technical challenges and risk of complications compared with primary knee arthroplasty. The purpose of this study was to compare two-year postoperative complication/revision rates between patients undergoing cTKA after prior periarticular open reduction and internal fixation (ORIF) and those undergoing primary TKA.MethodsPatients who underwent cTKA after prior periarticular ORIF of the ipsilateral knee were identified in a national all-payer claims database from 2010 to 2018. This ORIF-cTKA cohort was propensity matched to participants undergoing primary TKA based on age, gender, Charlson comorbidity index, and obesity status. Univariate analysis was performed to analyze differences in two-year complication and revision rates.ResultsAfter propensity matching, 823 patients were included in the ORIF-cTKA cohort and 1640 patients in the primary TKA cohort. No differences in demographics or comorbidities existed between cohorts. Relative to the primary TKA cohort, the ORIF-cTKA cohort had significantly higher incidences of all-cause revision (5.47% vs 2.47%, P = .001), periprosthetic joint infection (PJI; 4.74% vs 1.34%, P < .001), and intraoperative or postoperative periprosthetic fracture (1.58% vs 0.55%, P = .01) at two years postoperatively. There was also a nonsignificant trend toward increased rates of aseptic loosening (1.82% vs 0.91%, P = .052) in the ORIF-cTKA.ConclusionRelative to primary TKA, cTKA after periarticular ORIF is associated with significantly increased rates of all-cause revision, PJI, and periprosthetic fracture at two years postoperatively. Surgeons should counsel these patients about the increased risks of these postoperative complications and consider treating them as high risk for PJI in the perioperative period.     

Increased Medical Complications,Revisions, In-Hospital Lengths of Stay,and Cost in Patients With Hypogonadism Undergoing Primary Total Knee Arthroplasty

BackgroundResearch regarding the impact of hypogonadism following primary total knee arthroplasty (TKA) is limited. Therefore, the purpose of this study is to investigate whether patients with hypogonadism undergoing primary TKA are at increased odds of (1) medical complications, (2) revisions, (3) in-hospital lengths of stay (LOSs), and (4) cost of care.MethodsA Humana patient population consisting of 8 million lives was retrospectively analyzed from 2007 to 2017 using International Classification of Disease, 9th Revision codes. Patients were filtered by male gender and patients with hypogonadism were matched to controls in a 1:4 ratio according to age and medical comorbidities. The query yielded 8393 patients with (n = 1681) and without (6712) hypogonadism undergoing primary TKA. Primary outcomes analyzed included medical complications, revision rates, in-hospital LOS, and cost of care. Logistic regression analysis was used to calculate odds ratios (OR) of 90-day medical complications and 2-year revisions. Welch’s t-test was used to test for significance in LOS and cost of care between cohorts. A P-value less than .05 was considered statistically significant.ResultsHypogonadal patients undergoing primary TKA were found to have increased incidence and odds (9.45% vs 4.67%; OR 2.12, P < .0001) of developing 90-day medical complications. Hypogonadal patients undergoing primary TKA were found to have a greater incidence and odds (3.99% vs 2.80%; OR 1.89, P < .0001) of 2-year revisions. Hypogonadal patients had a 6.11% longer LOS (3.47 vs 3.27 days, P = .02) compared to controls, and incurred greater 90-day costs ($15,564.31 vs $14,856.69, P = .018) compared to controls.ConclusionThis analysis of over 1600 patients demonstrates that patients with hypogonadism undergoing primary TKA have greater odds of postoperative medical complications, revisions, increased LOS, and cost of care.     

Comparison of Surgical Site Complications With Negative Pressure Wound Therapy vs Silver Impregnated Dressing in High-Risk Total Knee Arthroplasty Patients: A Matched Cohort Study

BackgroundClosed incision negative pressure wound therapy (ciNPWT) may reduce surgical site complications following total joint arthroplasty. Although unlikely necessary for all patients, the criteria for utilizing ciNPWT in primary total knee arthroplasty (TKA) remain poorly defined. This study’s purpose was to compare the incidence of incisional wound complications, non-incisional complications (ie, dressing reactions), reoperations, and periprosthetic joint infections (PJIs) among a group of high-risk primary TKA patients treated with ciNPWT vs an occlusive silver impregnated dressing.MethodsOne hundred thirty high-risk primary TKA patients treated with ciNPWT were 1:1 propensity matched and compared to a historical control group treated with an occlusive silver impregnated dressing. High-risk criteria included the following: active tobacco use, diabetes mellitus, body mass index >35 kg/m², autoimmune disease, chronic kidney disease, Staphylococcus aureus nasal colonization, and non-aspirin anticoagulation.ResultsAge, gender, and risk factor profile were comparable between cohorts. The ciNPWT cohort had significantly fewer incisional wound complications (6.9% vs 16.2%; P = .031) and significantly more non-incisional complications (16.9% vs 1.5%; P < .001). No dressing reactions required clinical intervention. There were no differences in reoperations or periprosthetic joint infections (P = 1.000). In multivariate analysis, occlusive silver impregnated dressings (odds ratio 2.9, 95% confidence interval 1.3-6.8, P = .012) and non-aspirin anticoagulation (odds ratio 2.5, 95% confidence interval 1.1-5.6, P = .028) were associated with the development of incisional wound complications.ConclusionAmong high-risk patients undergoing primary TKA, ciNPWT decreased incisional wound complications when compared to occlusive silver impregnated dressings, particularly among those receiving non-aspirin anticoagulation. Although an increase in dressing reactions was observed, the clinical impact was minimal.     

How to Develop a Fair Revision Arthroplasty Bundle? Using Perioperative Complications and Readmissions to Investigate

BackgroundThe next frontier for value-based health care in total joint arthroplasty is revision surgery. Although the disparity in health care utilization between revision procedures compared with primary total hip and total knee arthroplasty (THA/TKA) procedures is recognized, no agreement regarding the risk adjustment necessary to make revision bundles fair to both payors and providers exists. The purpose of this study is to use the risk of perioperative complications and readmissions of patients undergoing revision THA/TKA to establish the foundations of a fair revision arthroplasty bundle.MethodsWe retrospectively evaluated a consecutive series of 484 aseptic THA/TKA revisions performed at our institution over a 12-month period and compared complications, length of stay, reoperations, and 90-day readmissions to a group of 802 consecutive patients undergoing primary THA/TKA.Results169 (34.9%) patients experienced major complications after revision THA/TKA compared with 176 (21.9%) patients undergoing primary THA/TKA (P < .001), (OR 1.91 CI 1.49-2.45, P < .001). Patients undergoing revision TKA were 3.64 times more likely to require hospitalization greater than 3 days (OR 2.59-5.12, CI 95%, P < .001), whereas patients undergoing revision THA were 4.46 times more likely to require hospitalization greater than 3 days (OR 2.89-6.87, CI 95%, P < .001). Revision patients were 3X more likely to have a 90-day readmission and 4X more likely to have a reoperation.ConclusionFor a revision bundle to be fair and widely adopted, either significant financial incentive must be instituted or the latitude given to exclude outliers from the final reconciliation. This must be adjusted to not disincentivize institutions from providing care for failed hip and knee arthroplasties.     

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.     

Is Bilateral Total Knee Arthroplasty Staged at a One-Week Interval Safe? A Matched Case Control Study

Controversy surrounds the safety of bilateral total knee arthroplasty (TKA) and whether staging the procedures one week apart represents a safer option. A consecutive series of 234 patients underwent either a simultaneous (103 patients) or staged bilateral TKA (131 patients) from 2007 to 2012 and were compared to a matched control group of unilateral TKA (131 patients). Staged patients had no difference in one-year complication rate when compared to simultaneous bilateral TKA and the matched unilateral TKA control group (15% vs. 19% vs. 15%, P = 0.512). There was also no difference in perioperative complications (10% vs. 14% vs. 7%, P = 0.231) or 90-day readmissions (8% vs. 4% vs. 4%, P = 0.295). In selected patients with bilateral knee OA, TKA staged at a one-week interval is a safe alternative.     

Conversion Total Knee Arthroplasty: Prior Fracture or Osteotomy Around the Knee Leads to Increased Resource Utilization

BackgroundPrior knee surgery before total knee arthroplasty (TKA) puts patients at higher risk of inferior outcomes and increased care cost. This study compares intraoperative and postoperative variables including procedure duration, components, length of stay, readmission, complications, and reoperations among patients undergoing conversion TKA.MethodsPrimary TKA from a single-surgeon database identified 130 patients with prior knee surgery to form a “conversion” cohort. One-to-one matching identified 130 patients of similar age, American Society of Anesthesiologists score, body mass index, and gender without prior knee surgery for comparison. Perioperative and 90-day postoperative variables were compared between patients with and without prior surgery, within the conversion group based on the type of prior surgery, and whether the prior surgery was bony or soft tissue.ResultsThe conversion group had longer mean operative time (96.1 vs 90.0 minutes, P = .01), higher revision component utilization (8.5% vs 0.8%, P = .005), and higher calculated blood loss (1440 vs 1249 mL, P = .004). Thirty-eight patients with prior fracture or osteotomy were compared to the remaining 92 patients in the conversion group and showed longer operative time (107.1 vs 91.3 minutes, P < .001), higher 90-day readmissions (18.4% vs 3.3%, P = .003), more complications (23.7% vs 8.7%, P = .021), and greater utilization of revision components (26.3% vs 1.1%, P < .001).ConclusionPatients undergoing conversion TKA required increased resource utilization, particularly patients with a prior osteotomy or fracture. Policymakers should consider these variables, as they did in conversion THA, in adding a code to account for increased case complexity and resource utilization.     

Interval Time of at Least 6 Weeks Between Bilateral Total Knee Arthroplasties is Associated With Decreased Postoperative Complications

BackgroundStaged, bilateral total knee arthroplasty (TKA) has an increased risk of complications if the second procedure is performed before physiologic recovery from the first. The aims of this study were to 1) determine whether there is a time-dependent relationship between TKA staging and rates of revisions and complications and 2) identify data-driven time intervals that reduce risk of revisions and complications.MethodsData were collected from a national insurance database from 2015 to 2018. Staged intervals were initially assessed using fixed 6-week intervals. Stratum-specific likelihood ratio analyses were subsequently conducted to observe data-driven staging thresholds. Bivariate and multivariable regression analyses were conducted to determine the associations between the time intervals and 2-year rates of revision surgery and 90-day major complications. We included 25,527 patients undergoing staged bilateral TKA.ResultsIn comparison to the shortest fixed time interval (1-6 weeks), as the staging interval increased the odds of 2-year all-cause revision and 90-day major complications significantly decreased (P < .05 for all). Stratum-specific likelihood ratio analysis identified 3 data-driven staging categories 1-5, 6-17, and 18-24 weeks that maximized the difference in both 2-year rates of revision and 90-day major complications.ConclusionOur data showed a time-dependent relationship between the timing of TKA stages and complications. If staging is considered, a delayed interval of at least 6 weeks between procedures may significantly reduce revision and major complications.Level of EvidenceLevel III Therapeutic Study.     

Has Removal From the Inpatient-Only List Increased Complications After Outpatient Total Knee Arthroplasty?

BackgroundOn 1/1/2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the Inpatient-Only (IPO) list. This change allowed expansion of outpatient TKA, potentially to include older, more frail patients at greater risk for perioperative complications. The purpose of this study was to evaluate the impact of removing TKA from the IPO list on early complications.MethodsPatients undergoing TKA in the National Surgical Quality Improvement Program database were identified using CPT code 27447. Only cases with length of stay of zero days were included. Rates of 30-day complications, readmissions, and reoperation were compared before and after TKA was removed from the IPO list (2015-2017 vs 2018). The analysis was performed both with and without propensity score matching.Results212,313 patients underwent TKA during the study period. 2466 (1.5%) were outpatient TKA in 2015-2017 and 3189 (5.6%) in 2018. After propensity matching, there were 2458 patients in each cohort. Rates of total 30-day complications were significantly lower in 2018 (3.7%) than the years TKA remained on the IPO (4.5%, P = .04). Similarly, rates of any reoperation decreased from 1.2% during 2015-2017 to 0.6% in 2018 (P = .03). There were no significant changes in rates of readmission (2.5% vs 2.2%, P = .5) or wound complications (0.8% vs 0.8%, P = 1.0).ConclusionRemoval of TKA from the IPO list did not result in an increase in complications or readmissions. These data suggest, despite the regulatory change, surgeons have continued to exercise sound judgment as to what patients can safely undergo outpatient TKA.     

Referral Bias in Primary Total Knee Arthroplasty: Retrospective Analysis of 22,614 Surgeries in a Tertiary Referral Center

Background

Patients who travel a significant distance to obtain surgical treatment typically experience better outcomes. This is called the referral bias and can limit the generalizability of studies performed at large tertiary care centers. We explored the influence of referral bias by comparing the clinical characteristics and outcomes of total knee arthroplasty (TKA) at a large tertiary care hospital in the United States.

Orthopedic Specialty Hospital Reasons for Transfer and Subsequent Outcomes

BackgroundSurgical specialty hospitals provide patients, surgeons, and staff with a streamlined approach to elective surgery but may not be equipped to handle all complications arising postoperatively. The purpose of this study is to evaluate the immediate postoperative and 90-day outcomes of patients who were transferred from a high-volume specialty hospital following primary total hip arthroplasty (THA) or total knee arthroplasty (TKA).MethodsAll patients who were admitted to one orthopedic specialty hospital for primary THA or TKA between January 2015 and December 2019, and subsequently transferred to a tertiary care hospital, were identified and propensity matched to nontransferred patients. Emergency department visits, complications, readmissions, mortality, and revisions within 90 days of surgery were identified for each group.ResultsThere were 26 TKAs (0.78%) and 20 THAs (0.48%) transferred, representing 0.62% of all primary THAs and TKAs performed over the study duration. Arrhythmia and chest pain were the most common reasons for transfer. Ninety-day readmissions were significantly higher in the transfer group (15.2% vs 4.3%, P = .020) with an odds ratio for readmission after transfer of 3.9 (95% confidence interval 1.3-12.4). Overall complications and orthopedic complications did not differ significantly, although transferred patients had a higher rate of medical complications (13.0% vs 2.2%, P = .008) with an odds ratio of 6.7 (95% confidence interval 1.6-28.2).ConclusionTransfer from a specialty hospital is rarely required following primary TKA and THA. Although not at increased risk for orthopedic complications, these transferred patients are at increased risk for readmissions and medical complications within the first 90 days of their care, necessitating increased vigilance.     

Staging Total Hip and Knee Arthroplasty Procedures Within 90 Days Increases Costs in Bundled Payment Programs

BackgroundUnder current Medicare bundled payment programs, when a patient undergoes a subsequent elective procedure within the 90-day episode-of-care, the first procedure is excluded from the bundle and a new episode-of-care initiated. The purpose of this study was to determine if staging bilateral total hip (THA) and total knee arthroplasty (TKA) procedures within 90 days have an effect on bundled episode-of-care costs.MethodsWe reviewed a consecutive series of Medicare patients undergoing staged primary THA and TKA from 2015-2019. Patients who underwent a prior procedure within 90 days were compared to those who had undergone a procedure 90-120 days prior. We then performed a multivariate analysis to identify the independent effect of staging timeframe on costs and outcomes.ResultsOf the 136 patients undergoing a staged bilateral THA or TKA, 48 patients underwent staged procedures within 90 days (35%) and 88 patients between 91-120 days (65%). There were no significant differences observed for demographics, comorbidities, complications, readmissions, or discharge disposition (all P > .05). Patients undergoing a staged procedure within 90 days had increased episode-of-care costs by $2021 (95% CI $11-$4032, P = .049), increased postacute care costs by $2019 (95% CI $66-$3971, P < .001), and reduced per-patient margin by $2868 (95% CI-$866-$4869, P = .005).DiscussionPatients undergoing staged bilateral THA or TKA within 90 days have increased episode-of-care costs compared to those undergoing a staged procedure from 91-120 days. Since patients may still not be fully recovered from the first procedure, CMS should address the inappropriate allocation of costs to ensure institutions are not penalized.     

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.     

Is early operative treatment for wound complications beneficial for preventing major component revision after TKA? A systematic review

BackgroundWound complications following TKA can progress to deep infection and compromise implant survivorship and clinical outcomes. However, it remains unclear whether early wound complications must undergo immediate surgical debridement or whether a trial of conservative treatment provides comparable outcomes. This study evaluates the rates of subsequent return to the operating room, deep infection, major reoperations and implant survivorship for early versus delayed operative management of superficial wound complications following TKA.Materials and methodsWe performed a systematic review of the literature indexed on PubMed and Embase and identified 14 studies which reported implant survivorship and deep infection rates following TKA wound complications. The data were aggregated to compare rates of secondary return to the OR, deep infection, and explants in patients with superficial wound complications following TKA managed with either early operative intervention versus conservative treatment.ResultsThe mean time to operative intervention was 17.7 days in the early operative group, compared to 12.8 days in the conservative management group. Rates of subsequent deep prosthetic joint infection were similar between the 2 groups (9.2% vs 5.2%, RR = 1.79, p = 0.098). However, there was a significant decrease in subsequent return to the OR for patients undergoing early surgical debridement compared to delayed surgical intervention (12.1% vs. 19.9%, RR = 0.609, p = 0.049). There were no significant differences between groups in terms of major revision rate (9.2% vs 4.6%, RR = 2.01 p = 0.053) or implant survivorship (95.7% vs. 95.4%, RR = 1.00, p = 0.869).ConclusionsIn wound complications following TKA, short delays in surgical management did not affect the overall rates of deep infection, major revision surgery, or implant survivorship. However, initial conservative treatment was associated with higher failure rates requiring subsequent return to the OR. We recommend that surgeons have a low threshold to return to the OR for early aggressive management of wound complications following TKA.     

Life After BPCI: High Quality Total Knee and Hip Arthroplasty Care Can Still Exist Outside of a Bundled Payment Program

BackgroundConcerns regarding target price methodology and financial penalties have led to withdrawal from Medicare bundled payment programs for total hip (THA) and knee arthroplasty (TKA), despite its early successful results. The purpose of this study was to determine whether there was any difference in patient comorbidities and outcomes following our institution’s exit from the Bundled Payments for Care Improvement - Advanced (BPCI-A).MethodsWe reviewed consecutive 2,737 primary TKA and 2,009 primary THA patients following our withdraw from BPCI-A January 1, 2020-March 30, 2021 and compared them to 1,203 TKA and 1,088 THA patients from October 1, 2018-August 2, 2019 enrolled in BPCI-A. We compared patient demographics, comorbidities, discharge disposition, complications, and 90-day readmissions.Multivariate analysis was performed to identify if bundle participation was associated with complications or readmissions.ResultsPost-bundle TKA had shorter length of stay (1.4 vs 1.8 days, P < .001). Both TKA and THA patients were significantly less likely to be discharged to a rehabilitation facility (5.6% vs 19.2%, P < .001 and 6.0% vs 10.0%, P < .001, respectively). Controlling for confounders, post-bundle TKA had lower complications (OR = 0.66, 95% CI 0.45-0.98, P = .037) but no difference in 90-day readmission (OR = 0.80, 95% CI 0.55-1.16, P = .224).ConclusionsSince leaving BPCI-A, we have maintained high quality THA care and improved TKA care with reduced complications and length of stay under a fee-for-service model. Furthermore, we have lowered rehabilitation discharge for both TKA and THA patients. CMS should consider partnering with high performing institutions to develop new models for risk sharing.     

Same-Day Discharge Total Knee Arthroplasty in Octogenarians

BackgroundOne of the most important aspects of the transition to outpatient (OP) arthroplasty is patient selection, with guidance traditionally recommending that OP total knee arthroplasty (TKA) be reserved for patients <80 years old. However, there are limited data as to whether older age should really be considered a contraindication to OP-TKA. The purpose of this study is to assess the risk of complications and readmissions following OP-TKA in patients ≥80 years old.MethodsThis is a retrospective, propensity-matched cohort study of the National Surgical Quality Improvement Program database from 2011 to 2019. Patients ≥80 years undergoing OP (same-day discharge) TKA were propensity matched to patients ≥80 years undergoing inpatient (IP) TKA based on age, gender, race, body mass index, American Society of Anesthesiologists classification, functional status, smoking status, anesthetic type, and medical comorbidities. There were 1,418 patients (709 IPs and 709 OPs) included. All baseline factors were successfully matched between IP-TKA versus OP-TKA (P ≥ .18 for all). Thirty-day complications, readmissions, reoperations, and mortality were subsequently analyzed.ResultsThirty-day readmission rates were identical between patients undergoing IP-TKA and OP-TKA (3.5% versus 3.5%, P = 1.0). Similarly, there was no significant difference in the incidence of major complications (2.7% versus 2.0%, P = .38), reoperations (1.3% versus 0.8%, P = .44), or mortalities (0.3% versus 0.3%, P = 1.0) within 30 days.ConclusionOctogenarians undergoing OP-TKA had comparable complication rates to similar patients undergoing IP-TKA. OP-TKA can be performed safely in select octogenarians and age ≥80 years likely does not need to be a uniform contraindication to OP-TKA.     

TKA is More Durable Than UKA for Morbidly Obese Patients: A Two-Year Minimum Follow-Up Study

BackgroundUnicompartmental knee arthroplasty (UKA) indications have expanded during the past two decades to include some morbidly obese patients (body mass index (BMI) > 40 kg/m²). Few published studies have compared UKA and total knee arthroplasty (TKA) in this unique patient subgroup with conflicting observations.MethodsWe retrospectively compared 89 mobile bearing UKA (71 patients) and 201 TKA (175 patients) performed at a single institution with a minimum 2-year follow-up (mean 3.4 years). Demographic characteristics were similar for both patient cohorts. A detailed medical record review was performed to assess the frequency of component revision, revision indications, minor secondary procedures (components retained), and infections.ResultsUKA was more frequently associated with clinical failure (29.2% vs 2.5%, P < .001) and component revision (15.7% vs 2.5%, P < .001), TKA was more frequently associated with extensor mechanism complications or knee manipulation (5.5% vs 0.0%, P = .02), and there was no difference in the infection rate (3.0% vs 2.2%, P = 1.0).ConclusionEarly complications were lower following UKA but were outweighed by higher component revision rates for arthritis progression and implant failure. The study findings suggest that TKA provides a more predictable mid-term outcome for morbidly obese patients considering knee arthroplasty surgery.     

Interval Between Staged Bilateral Total Knee Arthroplasties Does Not Affect Early Medical or Surgical Complications

BackgroundThe purpose of this study is to evaluate early postoperative surgical and medical complications in patients undergoing staged bilateral total knee arthroplasty (TKA) and determine if the interval to the second stage influences the risk of complications.MethodsA retrospective review was performed from 2016 through 2018 of all staged bilateral primary TKA procedures, yielding a cohort of 1005 patients (2010 TKAs). Four groups were created based on the timing of the second stage: 3 to 6 weeks, 7 to 12 weeks, 13 to 24 weeks, and >24 weeks. Clinical data compared between groups included demographics, knee range of motion, University of California, Los Angeles (UCLA) activity score, Knee Society pain score, Knee Society clinical score, and Knee Society functional score. Postoperative complications within 90 days were evaluated, with complications after the second knee being the primary outcome.ResultsThe mean follow-up after second stage was 10.7 months (range, 3 to 37 months). No significant differences were found between groups in the range of motion, Knee Society pain, Knee Society clinical score, Knee Society functional score, or University of California Los Angeles activity score in either the first or second knee. After the first knee surgery, medical complications were highest in the >24-week group. After the second knee, there were no significant difference in manipulation (P = .9), wound complications (P = .7), venous thromboembolism (P = .8), or other medical complications (P = 1) based on the interval duration.ConclusionThe interval between staged TKA did not affect early medical or surgical complications after the second stage. Early clinical and function results were not different based on timing of the second surgery.     

Is Conversion TKA a Primary or Revision? Clinical Course and Complication Risks Approximating Revision TKA Rather Than Primary TKA

BackgroundConversion total knee arthroplasty (convTKA) is associated with increased resource utilization and costs compared with primary TKA. The purpose of this study is to compare 1) surgical time, 2) hospitalization length (LOS), 3) complications, 4) infection, and 5) readmissions in patients undergoing convTKA to both primary TKA and revision TKA patients.MethodsThe American College of Surgeons National Surgical Quality Improvement Project database was queried from 2008 to 2018. Patients undergoing convTKA (n = 1,665, 0.5%) were defined by selecting Current Procedural Terminology codes 27,447 and 20,680. We compared the outcomes of interest to patients undergoing primary TKA (n = 348,624) and to patients undergoing aseptic revision TKA (n = 8213). Univariate and multivariate logistic regression was performed to identify the relative risk of postoperative complications.ResultsCompared with patients undergoing primary TKA, convTKA patients were younger (P < .001), had lower body mass index (P < .001), and were less likely to be American Society of Anesthesiologist class III/IV (P < .001). These patients had significantly longer operative times (122.6 vs 90.3 min, P < .001), increased LOS (P < .001), increased risks for any complication (OR 1.94), surgical site infection (OR 1.84), reoperation (OR 2.18), and readmissions (OR 1.60) after controlling for confounders. Compared with aseptic TKA revisions, operative times were shorter (122.6 vs 148.2 min, P < .001), but LOS (2.91 vs 2.95 days, P = .698) was similar. Furthermore, relative risk for any complication (P = .350), surgical site infection (P = .964), reoperation (P = .296), and readmissions (P = .844) did not differ.ConclusionConversion TKA procedures share more similarities with revision TKA rather than primary TKA procedures. Without a distinct procedural and diagnosis-related group, there are financial disincentives to care for these complex patients.Level of EvidenceII.