Does experience with total knee arthroplasty in morbidly obese patients effect surgical outcomes.

INTRODUCTION: Literature examining the risks, benefits, and potential complications of TKA in morbidly obese patients is conflicting. Surgeons with more experience performing TKA on morbidly obese patients may generate superior outcomes. This study sought to assess whether complication rates and implant survivorship in morbidly obese TKA patients varies between high (HV) and low (LV) volume surgeons. METHODS: A retrospective review was performed to include all morbidly obese (BMI ≥ 40) patients that underwent primary TKA between January 2016 and July 2021 at our high-volume center. Demographics and clinical outcomes were collected and compared between surgeons with a higher morbidly obese TKA volume (> 10 annual cases) and surgeons with a lower morbidly obese TKA volume. RESULTS: A total of 964 patients (HV 91 [9.4%], LV 873 [90.6%]) were identified. The HV surgeon and LV surgeons had an average annual volume of 15.3 and 5.2 cases, respectively. The average BMI for the HV and LV cohorts were 44.5 ± 3.7 and 44.0 ± 3.6, respectively (p = 0.160). The HV surgeon had significantly lower operative times (105.7 ± 17.4 vs. 110.7 ± 29.6 min, p = 0.018), and a lower 90-day minor complication rate (0.0% vs. 4.7%, p = 0.035). For patients with at least 2-year follow-up, all-cause revision (3.4% vs. 12.5%, p = 0.149) and revision due to PJI (0.0% vs. 5.8%, 0.193) rates were numerically lower in the HV cohort. Improvements in KOOS, JR and VR-12 scores were similar at 3-month and 1-year follow-up. Freedom from all-cause revision (HV: 96.6% vs. LV: 80.4%, p = 0.175) and revision due to PJI (HV: 100.0% vs. LV: 93.6%, p = 0.190, p = 0.190) at latest follow-up did not statistically differ between groups. CONCLUSION: The HV surgeon had significantly lower operative time and 90-day minor complication rates and numerically lower all-cause revision and revision due to PJI rates when performing TKA in morbidly obese patients. Surgeon's experience may affect surgical outcomes after TKA in morbidly obese patients. LEVEL OF EVIDENCE: III.

Peripheral Nerve Catheter Reduces Postoperative Opioid Consumption and Pain in Revision Total Knee Arthroplasty.

Background: Patients undergoing revision total knee arthroplasty (rTKA) have historically received high doses of opioids during the perioperative period. As awareness of opioid use has heightened, opioid administration has continuously decreased. This study aimed to evaluate if peripheral nerve catheter (PNC) use in rTKA reduces opiate consumption while maintaining similar pain control and postoperative function levels. Methods: A retrospective review of 354 patients who underwent rTKA between July 2019 and January 2022 was conducted. Fifty total patients who received an adductor canal PNC were propensity-matched 1:1 to a control group of 50 patients that did not receive a PNC. To assess the primary outcome of opiate consumption, nursing documented opiate administration events were converted into morphine milligram equivalents per 24-hour interval. Postoperative pain and functional status were assessed using the verbal rating scale for pain and the Activity Measure for Post-Acute Care scores, respectively. Results: Compared to the control group, the PNC group demonstrated significantly lower overall inpatient opiate consumption (98.68 ± 117.03 vs 176.69 ± 203.47 morphine milligram equivalents; 44.15% decrease, P = .021) and lower verbal rating scale pain scores at 60 to 72 hours postoperatively (4.85 ± 1.24 vs 5.83 ± 1.35; 16.81% decrease, P = .038). There was no significant difference in Activity Measure for Post-Acute Care scores postoperatively (raw score: 19.41 ± 3.61 vs 19.46 ± 3.18; 0.26% decrease, P = .952). Finally, the PNC cohort was significantly less likely to be readmitted within 90 days after surgery (0.0% vs 12.0%; P = .012). Conclusions: In rTKA patients, PNC can significantly reduce inpatient opioid consumption while maintaining a comparable functional recovery and superior pain control. Level III Evidence: Retrospective Cohort Study.

Ambulatory status after revision total hip arthroplasty in elective versus fracture indications.

INTRODUCTION: To improve revision total hip arthroplasty (rTHA) prognosis and postoperative management, a better understanding of how non-elective and elective indications influence clinical outcomes is needed. We sought to compare ambulatory status, complication rates, and implant survival rates in patients who underwent aseptic rTHA for periprosthetic fracture or elective indications. MATERIALS AND METHODS: This retrospective study examined all aseptic rTHA patients with a minimum follow-up of two years at a single tertiary referral center. Patients were divided into two groups: fracture rTHA (F-rTHA) if the patient had a periprosthetic femoral or acetabular fracture, and elective rTHA (E-rTHA) if the patient underwent rTHA for other aseptic indications. Multivariate regression was performed for clinical outcomes to adjust for baseline characteristics, and Kaplan-Meier analysis was performed to assess implant survival. RESULTS: A total of 324 patients (F-rTHA: 67, E-rTHA: 257) were included. In the F-rTHA cohort, 57 (85.0%) and 10 (15.0%) had femoral and acetabular periprosthetic fractures, respectively. F-rTHA patients were more likely to be discharged to skilled nursing (40.3% vs. 22.2%, p = 0.049) and acute rehabilitation facilities (19.4% vs. 7.8%, p = 0.004). F-rTHA patients had higher 90-day readmission rates (26.9% vs. 16.0%, p = 0.033). Ambulatory status at three months postoperatively significantly differed (p = 0.004); F-rTHA patients were more likely to use a walker (44.6% vs. 18.8%) and less likely to ambulate independently (19.6% vs. 28.6%) or with a cane (28.6% vs. 41.1%). These differences did not persist at one and two years postoperatively. Freedom from all-cause re-revision (77.6% vs. 74.7%, p = 0.912) and re-revision due to PJI (88.1% vs. 91.9%, p = 0.206) were similar at five-year follow-up. CONCLUSIONS: Compared to rTHA performed for elective aseptic indications, fracture rTHA patients had poorer early functional outcomes, with greater need for ambulatory aids and non-home discharge. However, these differences did not persist long term and did not portend increased infection or re-revision rates.

Does the geriatric nutritional risk index predict complication rates and implant survivorship in revision total joint arthroplasty?

INTRODUCTION: Malnutrition is associated with poorer outcomes after revision total joint arthroplasty (rTJA), though no universal metric for assessing malnutrition in rTJA patients has been reported. This study sought to determine if malnutrition as defined by the Geriatric Nutritional Risk Index (GNRI) can independently predict short-term complication rates and re-revision risk in patients undergoing rTJA. METHODS: All patients ≥ 65 years old undergoing rTJA from 2011 to 2021 at a single orthopaedic specialty hospital were identified. Preoperative albumin, height, and weight were used to calculate GNRI. Based on the calculated GNRI value, patients were stratified into three groups: normal nutrition (GNRI > 98), moderate malnutrition (GNRI 92-98), and severe malnutrition (GNRI < 92). Chi-squared and independent samples t-tests were used to compare groups. RESULTS: A total of 531 rTJA patients were included. Patients with normal nutrition were younger (p < 0.001), had higher BMI (p < 0.001). After adjusting for baseline characteristics, patients with severe and moderate malnutrition had longer length of stay (p < 0.001), were less likely to be discharged home (p = 0.049), and had higher 90-day major complication (p = 0.02) and readmission (p = 0.005) rates than those with normal nutrition. 90-day revision rates were similar. In Kaplan-Meier analyses, patients with severe and moderate malnutrition had worse survivorship free of all-cause re-revision at 1-year (p = 0.001) and 2-year (p = 0.002) follow-up compared to those with normal nutrition. CONCLUSION: Moderate and severe malnutrition, as defined by GNRI, independently predicted higher complication and revision rates in rTJA patients. This suggests that the GNRI may serve as an effective screening tool for nutritional status in patients undergoing rTJA.

Comparison of Aseptic Partial- and Full-Component Revision Total Knee Arthroplasty.

BACKGROUND: Revision total knee arthroplasty (rTKA) can be performed with isolated tibial, isolated femoral, and combined tibial and femoral component exchange for different indications. Replacement of only 1 fixed component in rTKA leads to shorter operative times and decreased complexity. We sought to compare functional outcomes and rates of rerevision in patients undergoing partial and full rTKA. METHODS: This retrospective study examined all aseptic rTKA patients with a minimum follow-up of 2 years in a single center between September 2011 and December 2019. Patients were divided into two groups: full rTKA (F-rTKA) if both components (femoral and tibial) were revised and partial rTKA (P-rTKA) if only 1 component was revised. A total of 293 patients (P-rTKA = 76, F-rTKA = 217) were included. RESULTS: P-rTKA patients had significantly shorter surgical time (109 ± 37 Versus. 141 ± 44 minutes, P < .001). At mean follow-up of 4.2 (range 2.2-6.2) years, rerevision rates did not significantly differ between groups (11.8 Versus. 16.1%, P = .358). Improvements in postoperative Visual Analogue Scale (VAS) pain and Knee Injury and Osteoarthritis Scale (KOOS), Joint Replacement scores were similar as well (P = .100 and P = .140, respectively). For patients undergoing rTKA due to aseptic loosening, freedom from rerevision due to aseptic loosening was similar between groups (100 Versus. 97.8%, P = .321). For patients undergoing rTKA due to instability, freedom from rerevision due to instability did not significantly differ as well (100 Versus. 98.1%, P = .683). In the P-rTKA cohort, freedom from all-cause and aseptic revision of preserved components was 96.1% and 98.7% at the 2-year follow-up. CONCLUSION: Compared to F-rTKA, P-rTKA yielded similar functional outcomes and implant survivorship with shorter surgical time. When indications and component compatibility allow for such a procedure, surgeons can expect good outcomes when performing P-rTKA.

Calibration of magnification in two-dimensional low-dose full-body imaging for preoperative planning of total hip arthroplasty.

INTRODUCTION: Preoperative planning of total hip arthroplasty (THA) using two-dimensional low-dose (2DLD) full-body imaging has gained popularity in recent years. The low-dose imaging system is said to produce a calibrated image with constant 1:1 magnification. However, the planning software used in conjunction with those images may introduce variations in the degree of magnification in 2DLD imaging, and this has not yet been investigated. The purpose of the present study was to quantify any variation in 2DLD image to assess the need for image calibration when using conventional planning software. METHODS: Postoperative 2DLD images from 137 patients were retrospectively evaluated. Only patients who underwent THA for primary osteoarthritis were included in the study cohort. The femoral head diameter was measured by two independent observers using both Orthoview™ and TraumaCad™ planning software programs. Actual sizes of the femoral head implants were extracted from surgical reports to calculate image magnification. Magnification measurement reliability was calculated with the intra-class correlation coefficient (ICC) index. RESULTS: Image magnification varied among cases (mean 133%, range 129-135%). There was no statistical difference in mean image magnification among the various implant sizes (p = 0.8). Mean observer and inter-observer reliability was rated excellent. CONCLUSION: THA planning with 2DLD imaging is subject to variation in magnification as analyzed with conventional planning software in this series. This finding is of paramount importance for surgeons using 2DLD imaging in preparation for THA since errors in magnification could affect the accuracy of preoperative planning and ultimately the clinical outcome.

Trends in Revision Total Hip Arthroplasty Cost, Revenue, and Contribution Margin 2011 to 2021.

BACKGROUND: Revision total hip arthroplasty (rTHA) is a costly procedure, and its prevalence has been steadily increasing over time. This study aimed to examine trends in hospital cost, revenue, and contribution margin (CM) in patients undergoing rTHA. METHODS: We retrospectively reviewed all patients who underwent rTHA from June 2011 to May 2021 at our institution. Patients were stratified into groups based on insurance coverage: Medicare, government-managed Medicaid, or commercial insurance. Patient demographics, revenue (any payment the hospital received), direct cost (any cost associated with the surgery and hospitalization), total cost (the sum of direct and indirect costs), and CM (the difference between revenue and direct cost) were collected. Changes over time as a percentage of 2011 numbers were analyzed. Linear regression analyses were used to determine the overall trend's significance. Of the 1,613 patients identified, 661 were covered by Medicare, 449 by government-managed Medicaid, and 503 by commercial insurance plans. RESULTS: Medicare patients exhibited a significant upward trend in revenue (P < .001), total cost (P = .004), direct cost (P < .001), and an overall downward trend in CM (P = .037), with CM for these patients falling to 72.1% of 2011 values by 2021. CONCLUSION: In the Medicare population, reimbursement for rTHA has not matched increases in cost, leading to considerable reductions in CM. These trends affect the ability of hospitals to cover indirect costs, threatening access to care for patients who require this necessary procedure. Reimbursement models for rTHA should be reconsidered to ensure the financial feasibility of these procedures for all patient populations.

Effects of Dexamethasone on Postoperative Glycemic Control in Diabetic Patients Following Primary Total Joint Arthroplasty: A Retrospective Cohort Study.

BACKGROUND: Concerns regarding the effects of dexamethasone on diabetics' glucose control have stymied its use following total joint arthroplasty. This study aimed to evaluate the effects of 2 intravenous (IV) perioperative doses of dexamethasone on glucose levels, pain scores, and inpatient opioid consumption following total joint arthroplasty in diabetic patients. METHODS: A retrospective review of 523 diabetic patients who underwent primary elective THA and 953 diabetic patients who underwent primary elective total knee arthroplasty (TKA) between May 6, 2020, and December 17, 2021 was conducted. Patients who received 1 dose (1D) of perioperative dexamethasone 10 mg IV were compared to patients who received 2 doses (2D). Primary outcomes included postoperative glucose levels, opioid consumption as morphine milligram equivalences, postoperative pain as Verbal Rating Scale pain scores, and postoperative complications. RESULTS: The 2D TKA cohort had significantly greater average and maximum blood glucose levels from 24 to 60 hours compared to the 1D TKA cohort. The 2D THA cohort had significantly greater average blood glucose levels at 24 to 36 hours compared to the 1D THA cohort. However, the 2D TKA group had significantly reduced opioid consumption from 24 to 72 hours and reduced total consumption compared to the 1D TKA group. Verbal Rating Scale pain scores did not differ between cohorts for both TKA and THA at any interval. CONCLUSION: Administration of a second perioperative dose of dexamethasone was associated with increased postoperative blood glucose levels. However, the observed effect on glucose control may not outweigh the clinical benefits of a second perioperative dose of glucocorticoids.

Hospital Teaching Status and Patient-Reported Outcomes Following Primary Total Hip Arthroplasty: An American Joint Replacement Registry Study.

INTRODUCTION: Previous studies have shown lower morbidity and mortality rates after total hip arthroplasty (THA) at academic teaching hospitals. This study sought to determine the relationship between hospital teaching status and patient-reported outcome measures following primary THA. METHODS: Using American Joint Replacement Registry data from 2012 to 2020, 4,447 primary, elective THAs with both preoperative and one year postoperative Hip disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS, JR) scores were analyzed. The main exposure variable was hospital teaching status, with three cohorts, as follows: major teaching hospitals, minor teaching hospitals, and non-teaching hospitals. Mean preoperative and one year postoperative HOOS, JR scores were compared. RESULTS: Preoperative HOOS, JR scores (nonteaching: 49.69 ± 14.42 versus major teaching: 47.68 ± 15.10 versus minor teaching: 42.46 ± 19.19, P < .001) were significantly higher at non-teaching hospitals than major and minor teaching hospitals, and these differences persisted at one year postoperatively (87.40 ± 15.14 versus 83.87 ± 16.68 versus 80.37 ± 19.27, P < .001). Both preoperative and postoperative differences in HOOS, JR scores were less than the minimum clinically important difference (MCID) at both time points. In multivariate regressions, non-teaching and minor teaching hospitals had similar odds of MCID achievement in HOOS, JR scores compared to major teaching hospitals. CONCLUSION: Using the HOOS, JR score as a validated outcome measure, undergoing primary THA at an academic teaching hospital did not correlate with higher postoperative HOOS, JR scores or greater chances of MCID achievement in HOOS, JR scores compared to non-teaching hospitals. Further work is required to determine the most important factors that may lead to improvement in patient-reported outcomes following THA.

The AAHKS Best Podium Presentation Research Award: A Second Dose of Dexamethasone Reduces Postoperative Opioid Consumption and Pain in Total Joint Arthroplasty.

BACKGROUND: The optimal administration of dexamethasone for postoperative pain management and recovery following primary elective total joint arthroplasty (TJA) remains unclear. This study aimed to evaluate the effect of a second intravenous (IV) dose of dexamethasone on postoperative pain scores, inpatient opioid consumption, and functional recovery after total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: A retrospective review was conducted of 2,256 primary elective THAs and 1,951 primary elective TKAs between May 2020 and April 2021. Patients who received 2 perioperative doses (2D) of dexamethasone 10 mg IV were propensity-matched 1:1 to a control group who received 1 perioperative dose (1D). Primary outcomes were opiate consumption as morphine milligram equivalences (MMEs), postoperative pain as Verbal Rating Scale (VRS) pain scores, and functional status assessed by the Activity Measure for Post-Acute Care (AM-PAC) scores. RESULTS: The 2D THA and 2D TKA cohorts consumed significantly less opiates at the 24 to 48-hour and 48 to 72-hour intervals. The 2D TKA cohort had significantly lower total opiate consumption compared to the 1D TKA cohort. Compared to the 1D cohorts, the 2D THA cohort and 2D TKA cohorts had significantly lower pain scores at the 48 to 60-hour interval; additionally, the 2D TKA cohort had significantly lower pain scores in the 36 to 48-hour interval. AM-PAC scores did not differ between cohorts for both TKA and THA at any interval. CONCLUSION: The administration of a second perioperative dexamethasone dose significantly decreased opioid consumption in the immediate postoperative period. Inpatient opioid administration can be significantly reduced while maintaining comparable functional recovery and superior pain control. LEVEL III EVIDENCE: Retrospective Cohort Study.

Clinical and Radiographic Outcomes of a Monoblock Fluted Titanium-Tapered Stem for Paprosky IIIa, IIIb, and IV Femoral Bone Defects.

BACKGROUND: Modern fluted titanium-tapered stems (FTTS) have been increasingly utilized to achieve primary stability in conversion and revision total hip arthroplasty with major femoral bone loss. This study sought to determine the radiographic and clinical outcomes of a monoblock FTTS in patients who had major femoral bone loss. METHODS: A multicenter retrospective observational study of all total hip arthroplasty patients who received a monoblock FTTS who had up to 5-year radiographic follow-up was conducted. Only patients with femoral Paprosky classifications of IIIa, IIIb, and IV were included. Eighty-one monoblock FTTS were examined. Median clinical follow-up was 29 months (range, 18 to 58). Stem subsidence and loosening were assessed on most recent radiographs. All-cause revisions and stem survivals were assessed. RESULTS: Median subsidence was 1.4 millimeters (mm) (range, 0 to 15.0). Sixteen (23.9%) and 3 (4.5%) stems had subsidence greater than 5 and 10 mm, respectively. All stems not acutely revised appeared stable, without evidence of loosening, at latest follow-up. Ten hips (12.3%) required reoperations. Of these, only 5 (6.2%) stems were removed; 4 due to periprosthetic joint infection and 1 for surgical exposure during acetabular revision. Kaplan-Meier analyses yielded an all-cause stem survivorship of 95.1% at 2-years and 87.1% at 4-years. Stem survivorships excluding septic causes was 98.8% at both 2 and 4 years. CONCLUSION: Monoblock FTTS in complex femoral reconstruction cases showed encouraging clinical and radiographic results in patients who had severe femoral bone loss at median 29 months follow-up.

Comparison of traditional PS versus kinematically designs in primary total knee arthroplasty.

PURPOSE: Kinematically designed total knee arthroplasty (TKA) aims to restore normal kinematics by replicating the function of both cruciate ligaments. Traditional posterior-stabilized (PS) TKA designs, on the other hand, simplify knee kinematics and may improve TKA cost-effectiveness. The purpose of this study was to compare outcomes of patients who underwent primary TKA using either a traditional PS or kinematically designed TKA. METHODS: This retrospective study examined all patients who underwent primary TKA using either a kinematically or a traditional PS designed TKA implant, with a minimum follow-up of 2 years. Patient demographics, complications, readmissions, revision rates and causes, range of motion (ROM) and patient reported outcomes (KOOS, JR) were compared between groups. Kaplan-Meier survivorship analysis was performed to estimate freedom from revision, and multivariate regression was performed to control for confounding variables. RESULTS: A total of 396 TKAs [173 (43.7%) with a kinematic design, 223 (56.3%) with a traditional design] with a mean follow-up of 3.48 ± 1.51 years underwent analysis. Revision rates did not differ between groups (9.8% vs. 6.7%, p = 0.418). In Kaplan-Meier analysis at 2-year follow-up, freedom from all-cause revision (96.4% vs. 93.1%, p = 0.139) were similar between groups. The two cohorts had no significant difference in aseptic loosening at 2 years (99.6% vs. 97.1, p = 0.050) and at latest follow up (92.7% vs. 96.4%, p = 0.279). KOOS, JR scores and post-operative ROM were similar between groups. CONCLUSION: This study demonstrated similar mid-term outcomes following the use of both a kinematically designed and a traditionally designed implant in primary TKA patients. LEVEL OF EVIDENCE: Retrospective study-III.

Are we getting better at cementing femoral stems in total hip arthroplasty? A 5-year institutional trend.

INTRODUCTION: Femoral stem cementation provides excellent implant longevity with a low periprosthetic fracture rate among patients with compromised bone quality or abnormal anatomy. We radiologically evaluated the quality of the femoral cement mantle in patients undergoing THA to examine whether cementation quality improved with increased institutional experience. METHODS: A retrospective study of 542 primary elective THAs performed using cemented stems from 2016 to 2021 at a high-volume orthopedic specialty center was conducted. Immediate post-operative anterior-posterior (AP) and lateral radiographs were evaluated to assess cement mantle quality based on the Barrack classification. Cement mantles were deemed satisfactory (Barrack A and B) or unsatisfactory (Barrack C and D). Regression was performed to identify predictors of unsatisfactory cementation quality. RESULTS: The annual cemented primary THA volume increased throughout the study period from 14 cases in 2016 to 201 cases in 2021. Overall, the majority of cement mantles were deemed satisfactory; 91.7% on AP radiographs and 91.0% on lateral radiographs. Satisfactory cementation on AP radiograph achievement rates improved during the study period, which coincided with greater annual volume (p < 0.001). No association was found between posterior and direct anterior surgical approaches and satisfactory cementation quality on both AP and lateral radiographs. CONCLUSION: Majority of femoral stems had satisfactory cementation quality. Higher institutional annual cemented THA volume was associated with improved cementation quality. Residency and fellowship training programs should place greater emphasis on the importance of femoral stem cementation for appropriately indicated patients. LEVEL OF EVIDENCE: III, retrospective cohort study.

Preoperatively elevated HbA1c levels can meaningfully improve following total joint arthroplasty.

BACKGROUND: Prior literature has demonstrated that diabetic (DM) patients undergoing total joint arthroplasty (TJA) with elevated preoperative HbA1c scores have poorer clinical outcomes. However, no literature has reported the effect of undergoing TJA on laboratory markers of glycemic control. This study sought to evaluate effect of undergoing TJA on postoperative glycemic control and outcomes. METHODS: This retrospective study reviewed all patients with DM who underwent primary, elective TJA at our high volume orthopedic institution. Included patients had at least one HbA1c value 3 months to 2 weeks pre-surgery and 3-6 months after surgery. Changes in HbA1c from before to after surgery were calculated. Change in HbA1c greater than 1.0% was considered clinically meaningful. Change in HbA1c was analyzed and stratified into subgroups. RESULTS: In total, 770 primary TJA patients were included. Patients with preoperative HbA1c > 7% vs. ≤ 7% were significantly more likely to have clinically meaningful post-TJA decrease in HbA1c (24.5 vs. 2.9%, p < 0.001). Patients with preoperative HbA1c > 8 were significantly more likely to have decrease of > 2.0 compared to those with HbA1c < 8 (p < 0.001). Multivariate regression revealed that preop HbA1c > 7.0, former and current smokers, males, and African-Americans were significantly more likely to achieve clinically meaningful decrease in HbA1c. Additionally, postoperative increase in HbA1c > 1% was associated with significantly higher 90-day ED visits. DISCUSSION: Patients with higher preoperative HbA1c were more likely to have clinically meaningful decreases in HbA1c postoperatively. A combination of preoperative medical optimization and improvements in mobility after TJA may play a role in these changes. Those with elevated HbA1c can have meaningful improvement in HbA1c after TJA.

The Association of Metabolic Syndrome on Complications and Implant Survivorship in Primary Total Knee Arthroplasty in Morbidly Obese Patients.

BACKGROUND: Metabolic syndrome (MetS) includes interrelated conditions such as insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study sought to determine the association of MetS in morbidly obese patients (body mass index >40) on complications and clinical outcomes after primary total knee arthroplasty (TKA). METHODS: A retrospective review was performed to include all morbidly obese patients who underwent primary elective TKA for osteoarthritis at a single academic institution. Patients who did and did not have MetS were propensity-matched 1:1 based on baseline characteristics. A total of 391 patients who did and 935 who did not have MetS were included having a mean body mass index of 44.2 (range, 40.0 to 68.9). RESULTS: The MetS patients had longer lengths of stay (LOS) (3.5 ± 2.4 versus 3.0 ± 1.5 days, P = .001) and were more likely to be discharged to skilled nursing facilities (23.8 versus 15.3%, P = .007). At 90 days postoperatively, major (P = .756) and minor (P = .652) complication rates and readmissions (P = .359) were similar. Revision rates as well as improvements in KOOS-JR, and VR-12 mental and physical component scores from preoperative to 1 year (P = .856, P = .524, and P = .727, respectively) postoperatively did not significantly differ between groups. MetS and non-MetS patients had similar 5-year freedom from all-cause revision (90.2 versus 94.2%, P = .791). CONCLUSION: Morbidly obese patients who have MetS had longer LOS and higher discharges to skilled nursing facilities. The 90-day complications, readmissions, revision rates, and patient-reported outcomes were similar, suggesting that resource allocation should be focused on perioperative protocols that can help optimize LOS and discharge dispositions in morbidly obese MetS patients undergoing TKA. LEVEL OF EVIDENCE: III.

The Effect of Surgeon and Hospital Volume on Total Hip Arthroplasty Patient-Reported Outcome Measures: An American Joint Replacement Registry Study.

BACKGROUND: Some studies have shown lower morbidity and mortality rates with increased surgeon and hospital volumes after total hip arthroplasty (THA). This study sought to determine the relationship between surgeon and hospital volumes and patient-reported outcome measures after THA using American Joint Replacement Registry data. METHODS: Using American Joint Replacement Registry data from 2012 to 2020, 4,447 primary, elective THAs with both preoperative and 1-year postoperative Hip Dysfunction and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR) scores were analyzed. This study was powered to detect the minimum clinically important difference (MCID). The main exposure variables were median annual surgeon and hospital volumes. Tertiles were formed based on the median annual number of THAs conducted: low-volume (1 to 42), medium-volume (42 to 96), and high-volume (≥96) surgeons and low-volume (1 to 201), medium-volume (201 to 392), and high-volume (≥392) hospitals. Mean preoperative and 1-year postoperative HOOS-JR scores were compared. RESULTS: Preoperative HOOS-JR scores were significantly higher at high-volume hospitals than low-volume and medium-volume hospitals (49.66 ± 15.19 vs. 47.68 ± 15.09 and 48.34 ± 15.22, P < 0.001), although these differences were less than the MCID. At the 1-year follow-up, no difference was noted with no resultant MCID. Preoperative and 1-year HOOS-JR scores did not markedly vary with surgeon volume. In multivariate regression, low-volume and medium-volume surgeons and hospitals had similar odds of MCID achievement in HOOS-JR scores compared with high-volume surgeons and hospitals, respectively. CONCLUSION: Using the HOOS-JR score as a validated patient-reported outcome measure, higher surgeon or hospital THA volume did not correlate with higher postoperative HOOS-JR scores or greater chances of MCID achievement in HOOS-JR scores compared with medium and lower volume surgeons and hospitals.

Novel metaphyseal porous titanium cones allow favorable outcomes in revision total knee arthroplasty.

INTRODUCTION: Loosening and migration are common modes of aseptic failure following complex revision total knee arthroplasty (rTKA). Metaphyseal cones allow surgeons to negotiate the loss of femoral and tibial bone stock while obtaining stable bony fixation. This study examines the mid-term functional and radiographic outcomes in patients undergoing rTKA utilizing a novel metaphyseal cone system with stems of variable length and fixation methods. METHODS: This two-center retrospective study examined all patients who underwent rTKA with a novel porous, titanium tibial or femoral cone in combination with a stem of variable length and fixation who had a minimum follow-up of 2-years. Outcome analysis was separated into tibial and femoral cones as well as the stem fixation method (hybrid vs. fully cemented). RESULTS: Overall, 123 patients who received 156 cone implants were included (74 [60.2%] tibial only, 16 [13.0%] femoral only, and 33 [26.8%] simultaneous tibial and femoral) with a mean follow-up of 2.76 ± 0.66 years. At 2-years of follow-up the total cohort demonstrated 94.3% freedom from all-cause re-revisions, 97.6% freedom from aseptic re-revisions, and 99.4% of radiographic cone osteointegration. All-cause revision rates did not differ between stem fixation techniques in both the tibial and femoral cone groups. CONCLUSION: The use of a novel porous titanium femoral and tibial metaphyseal cones combined with stems in patients with moderate to severe bone defects undergoing complex revision total knee arthroplasty confers excellent results independent of stem fixation technique. LEVEL OF EVIDENCE: IV, case series.

Primary total hip arthroplasty in patients older than 90 years of age: a retrospective matched cohort study.

INTRODUCTION: Advanced age is considered a major risk factor for postoperative complications in total hip arthroplasty (THA). Consequently, older patients undergoing THA may require more detailed pre-procedural examinations and more healthcare resources postoperatively than younger patients. The purpose of this study was to compare discharge parameters and complication rates of THA in patients ⩾90 years old to those <90 years old. METHODS: A retrospective review of 14,824 THA patients from 2011 to 2021 at a high-volume, urban academic centre was conducted. Patients ⩾90 years old were propensity-matched to a control group of patients aged <90 years old. Patient demographics, surgical time, hospital length of stay (LOS), discharge disposition, and 90-day revision, readmission, and mortality rates were collected. Demographic differences and outcomes were assessed using chi-square and independent sample t-tests. RESULTS: After propensity matching, the average age in the younger cohort (YC, n = 54) was 75.81 ± 7.89, and 91.61 ± 1.73 for the older cohort (OC, n = 54). The OC had a longer LOS than the YC (mean 3.90 vs. 3.06 days; p = 0.031). Discharge disposition significantly differed (p = 0.007); older patients were more likely to be discharged to skilled nursing facilities (33.3% vs. 14.8%) or acute rehabilitation centres (14.8% vs. 3.7%) and less likely to be discharged to prior place of residence (home self-managed/home with services, 51.9% vs. 79.6%). There was no significant difference in surgical time (93.87 ± 29.75 vs. 96.09 ± 26.31 min; p = 0.682), 90-day revision rate (3.7% vs. 0%; p = 0.153), 90-day readmission rate (9.4% vs. 3.7%; p = 0.543), and 90-day mortality rate (1.9% vs. 1.9%; p = 1.000). CONCLUSIONS: Although THA patients over 90 years of age had a longer LOS and differing discharge disposition, these patients had similar complications compared to their younger counterparts. Thus, our study supports similar efficacy of THA in patients 90 years and older relative to younger THA candidates.

The learning curve associated with imageless navigation in total knee arthroplasty.

INTRODUCTION: Computer-assisted navigation systems (CAS) are increasingly being integrated into total knee arthroplasty (TKA) procedures, but perceptions of associated learning curve and increased operative time continue to curtail uptake. Newer-generation navigational systems aim to streamline integration into surgical workflow to mitigate increases in operative time. Here, we assess the impact of a novel imageless CAS on operative time for TKA. METHODS: A retrospective analysis of prospectively collected data of a cohort of patients undergoing primary unilateral TKA with one of three surgeons between October 2019 and March 2020 was conducted. Consecutive cases using a novel imageless CAS were included in analysis. For each surgeon, average operative time was recorded and compared in sequential five-case cohorts to average operative time for the same procedure performed conventionally using a two-tailed t test. RESULTS: Average conventional operative times were 95.9 ± 15.0, 86.6 ± 13.7, and 116.9 ± 25.1 min for the three surgeons. Initial CAS-assisted operative times increased to 107.0 ± 9.8 (p = 0.07) and 102.4 ± 13.2 (p = 0.06) min for Surgeons 1 and 2 and decreased to 113.2 ± 9.8 min (p = 0.52) for Surgeon 3. Most recent CAS-assisted operative times were 94.8 ± 13.9 (p = 0.88), 88.7 ± 15.3 (p = 0.84), and 104.8 ± 13.2 (p = 0.12) min as compared to pre-CAS. Absolute differences for the most recent navigated procedures ranged from 12.1 min faster to 2.0 min slower. CONCLUSION: The learning curve for TKA navigation may be as few as 10 cases, and any associated increases in operative time may be transient and non-significant. Moreover, navigation may ultimately speed operative time, perhaps as the result of enhanced intraoperative assessment of alignment.

Effect of documented and undocumented psychiatric conditions on length of stay and discharge destination after total knee arthroplasty.

INTRODUCTION: Length of stay (LOS) and readmissions are quality metrics linked to physician payments and substantially impact the cost of care. This study aims to evaluate the effect of documented and undocumented psychiatric conditions on LOS, discharge location, and readmission following total knee arthroplasty (TKA). METHODS: Retrospective review of all primary, unilateral TKA from 2015 to 2020 at a high-volume, academic orthopedic hospital was conducted. Patients were separated into three cohorts: patients with a documented psychiatric diagnosis (+Dx), patients without a documented psychiatric diagnosis but with an actively prescribed psychiatric medication (-Dx), and patients without a psychiatric diagnosis or medication (control). Patient demographics, LOS, discharge location, and 90 days readmissions were assessed. RESULTS: A total of 2935 patients were included; 1051 patients had no recorded psychiatric medications (control); 1884 patients took at least one psychiatric medication, of which 1161 (61.6%) were in the-Dx and 723 (38.4%) were in the +Dx cohort. Operative time (+Dx, 103.4 ± 29.1 and -Dx, 103.1 ± 28.5 vs. 93.6 ± 26.2 min, p < 0.001 for both comparisons) and hospital LOS stay (+ Dx, 3.00 ± 1.70 and -Dx, 3.01 ± 1.83 vs. 2.82 ± 1.40 days, p = 0.021 and p = 0.006, respectively) were greater for patients taking psychiatric medications when compared to the control group. Patients taking psychiatric medication with or without associated diagnosis were significantly more likely to be discharged to a secondary facility-22.8% and 20.9%, respectively-compared to controls, at 12.5% (p < 0.001). Ninety-day readmission rates did not differ between the control and both psychiatric groups (p = 0.693 and p = 0.432, respectively). CONCLUSION: TKA patients taking psychiatric medications with or without a documented psychiatric diagnosis have increased hospital LOS and higher chances of discharge to a secondary facility. Most patients taking psychiatric medication also had no associated diagnosis. Payment models should consider the presence of undocumented psychiatric diagnoses when constructing metrics. Surgeons and institutions should also direct their attention to identifying, recording, and managing these patients to improve outcomes. LEVEL III EVIDENCE: Retrospective Cohort Study.