Simultaneous versus Staged Bilateral Total Hip Arthroplasty - A Matched Cohort Analysis of Revenue and Contribution Margin.

INTRODUCTION: Though previous studies have demonstrated improved cost benefits associated with simultaneous versus staged bilateral total hip arthroplasty (simBTHA and staBTHA), further investigation is needed regarding the revenues and contribution margins (CM) of these procedures. In this study, we compared revenue, CM, and surgical outcomes between simBTHA and staBTHA. METHODS: All patients who underwent simBTHA (both procedures completed the same day) and staBTHA (procedures completed on different days within one year) between 2011 and 2021 at a single high-volume orthopaedic specialty hospital were identified. Of the 1,517 identified patients (n = 139 simBTHA, n = 1,378 staBTHA), 232 were included in a 1:1 propensity match based on baseline demographics (116 per cohort). Revenue, costs, CM, and surgical outcomes were compared between cohorts. RESULTS: Compared to staBTHA, simBTHA procedures had significantly lower total costs (P < 0.001), direct costs (P < 0.001), and patient revenue. There was no significant difference in CM between groups (P = 0.361). Additionally, there were no significant differences in length of stay (P = 0.173), operative time (P = 0.438), 90-day readmissions (P = 0.701), 90-day revisions (P = 0.313), or all-cause revisions (P = 0.701) between cohorts. CONCLUSIONS: Though simBTHA procedures have lower revenues than staBTHA, they also have lower costs, resulting in similar CM between procedures. As both procedures have similar postoperative complication rates, further research is required to evaluate specifically which patients may benefit from simBTHA versus staBTHA regarding clinical and patient-reported outcomes.

Total hip arthroplasty outcomes in Ehlers-Danlos patients: data from the Statewide Planning and Research Cooperative System.

INTRODUCTION: Ehlers-Danlos syndromes (EDS) are genetic connective tissue disorders affecting multiple organ systems that frequently result in connective tissue hyperlaxity and early osteoarthritis. Short- and long-term outcomes after primary total hip arthroplasty (THA) in this patient population remain poorly characterised. The primary purpose of this study is to compare postoperative outcomes and survivorship after primary THA in patients with and without EDS. METHODS: The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried for all patients undergoing primary elective THA between September 2009 and December 2020. Patients with EDS were identified using ICD9 and ICD10 diagnosis codes. Given the relatively low incidence of EDS in this patient population, the cohort was propensity-matched 1:10 to patients without diagnosis of EDS based on demographics characteristics and medical comorbidities as measured by the Elixhauser Comorbidity Index. RESULTS: A total of 66 THA patients with and 660 without EDS were included in each group after 1:10 propensity-matching. There were no significant differences in baseline characteristics or THA indications. Early postoperative outcomes such as length of hospital stay and discharge disposition were similar. Emergency Room visits and inpatient readmission rates at 3 months postoperatively did not significantly differ between groups. Patients with EDS had a higher overall revision rate compared to those without (15.0% vs. 3.2%, p < 0.001). Revision free survival after primary THA in patients with EDS was significantly lower than those without EDS at 9-year follow-up. Cox proportional hazard regression demonstrated EDS patients had 7-times higher risk of revision (hazard ratio [HR] 7.43; 95% CI, 3.46-16.00; p < 0.001). Lastly, revision due to instability insignificantly trended higher in the EDS cohort (HR 2.29; 95% CI, 0.95-5.49; p = 0.063). CONCLUSIONS: EDS patients undergoing primary THA have increased rate of all cause revision and demonstrate decreased revision free survival compared to non-EDS THA patients.

Patient-reported outcome differences for navigated and robot-assisted total hip arthroplasty frequently do not achieve clinically important differences: a systematic review.

INTRODUCTION: Total hip arthroplasty (THA) using computer-assisted navigation (N-THA) and robot-assisted surgery (RA-THA) has been increasingly adopted to improve implant positioning and offset/leg-length restoration. Whether clinically meaningful differences in patient-reported outcomes (PROMs) compared to conventional THA (C-THA) are achieved with intraoperative technology has not been established. This systematic review aimed to assess whether published relative PROM improvements with technology use in THA achieved minimal clinically important differences (MCIDs). METHODS: PubMed/MEDLINE/Cochrane Library were systematically reviewed for studies comparing PROMs for primary N-THA or RA-THA with C-THA as the control group. Relative improvement differences between groups were compared to established MCID values. Reported clinical and radiographic differences were assessed. Review of N-THA and RA-THA literature yielded 6 (n = 2580) and 10 (n = 2786) studies, respectively, for analyses. RESULTS: Statistically significant improvements in postoperative PROM scores were reported in 2/6 (33.3%) studies comparing N-THA with C-THA, though only 1 (16.7%) reported clinically significant relative improvements. Statistically significant improvements in postoperative PROMs were reported in 6/10 (60.0%) studies comparing RA-THA and C-THA, though none reported clinically significant relative improvements. Improved radiographic outcomes for N-THA and RA-THA were reported in 83.3% and 70.0% of studies, respectively. Only 1 study reported a significant improvement in revision rates with RA-THA as compared to C-THA. CONCLUSIONS: Reported PROM scores in studies comparing N-THA or RA-THA to C-THA often do not achieve clinically significant relative improvements. Future studies reporting PROMs should be interpreted in the context of validated MCID values to accurately establish the clinical impact of intraoperative technology.

The Financial Feasibility of Bilateral Total Knee Arthroplasty: A Matched Cohort Analyses of Revenue and Contribution Margin Between Simultaneous and Staged Procedures.

BACKGROUND: Financial analyses of simultaneous bilateral total knee arthroplasty versus staged bilateral total knee arthroplasty (simBTKA and staBTKA, respectively) have shown improved cost-effectiveness of simBTKA, though revenue and contribution margin (CM) for these procedures have not been investigated. Our analyses compared surgical outcomes, revenues, and CMs between simBTKA and staBTKA. METHODS: We retrospectively reviewed all patients who underwent simBTKA (both procedures done on the same day) and staBTKA (procedures done on a different day within one year) between 2012 and 2021. Patients were 1:1 propensity matched based on baseline characteristics. Surgical outcomes, as well as revenue, cost, and CM of the inpatient episode were compared between groups. Of the 2,357 patients evaluated (n = 595 simBTKA, n = 1,762 staBTKA), 410 were included in final matched analyses (205 per group). RESULTS: Total (P < .001) and direct (P < .001) costs were significantly lower for simBTKA procedures compared to overall costs of both staBTKA procedures. Significantly lower revenue for simBTKA procedures (P < .001), resulted in comparable CM between groups (P = .477). Postoperative complications including 90-day readmission (P = 1.000), 90-day revision (P = 1.000) and all-cause revision at latest follow-up (P = .083) were similar between groups. CONCLUSIONS: In our propensity-matched cohort, lower costs for simBTKA compared to staBTKA were matched by lower revenues, with a resulting similar CM between procedures. Given that postoperative complication rates were similar, both procedures had comparable cost-effectiveness. Future research is needed to identify patients for whom simBTKA may represent a better surgical intervention compared to staBTKA with respect to clinical and patient reported outcomes.

Are Patient Outcomes Affected by Surgeon Experience With Total Hip Arthroplasty in Morbidly Obese Patients?

Background: Surgeons with high volume (HV) of total hip arthroplasty (THA) have seen better outcomes than low volume (LV) surgeons. However, literature regarding surgeon volume and outcomes in morbidly obese THA patients is scarce. This study examines the association between surgeon volume with THA in morbidly obese patients (body mass index ≥40) and their clinical outcomes. Methods: We retrospectively reviewed all morbidly obese patients who underwent primary THA at our institution between March 2012 and July 2020 with 2 years of follow-up. Clinical outcomes were compared between the HV (HVa, top quartile of surgeons with the highest overall yearly THA volume) and LV (LVa) surgeons. Similar analysis was run comparing HV of morbidly obese THA (HVo, top quartile of surgeons with the highest yearly morbidly obese THA volume) and LV of morbidly obese THA (LVo) surgeons. Results: Six hundred and forty-three patients and 33 surgeons were included. HVa surgeons had significantly shorter length of stay and increased home discharge. HVa and HVo surgeons had significantly shorter operative times. There were no significant differences in overall 90-day major and minor complications or clinical differences in patient-reported outcomes. Revision rates and freedom from revisions did not differ between groups at 2-year follow-up. Conclusions: HVa surgeons had significantly lower length of stay and operative times and increased discharge to home. There was no significant decrease in complications or revisions in either comparison model. Complications, revision rates, and patient satisfaction in morbidly obese patients who undergo THA may be independent of surgeon volume.

Does body mass index influence improvement in patient reported outcomes following total knee arthroplasty? A retrospective analysis of 3918 cases.

PURPOSE: The study aimed to determine whether body mass index (BMI) classification for patients undergoing total knee arthroplasty (TKA) is associated with differences in mean patient reported outcome measure (PROM) score improvements across multiple domains-including pain, functional status, mental health, and global physical health. We hypothesized that patients with larger BMIs would have worse preoperative and postoperative PROM scores, though improvements in scores would be comparable between groups. MATERIALS AND METHODS: Patients undergoing primary TKA from 2018 to 2021 were retrospectively reviewed and stratified into four groups: Normal Weight; 18.5-25 kg/m2, Overweight; 25.01-30 kg/m2, Obese; 30.01-40 kg/m2, and Morbidly Obese > 40 kg/m2. Preoperative, postoperative, and pre/post-changes (Δ) in knee injury and osteoarthritis, joint replacement (KOOS, JR) and Patient-Reported Outcome Measurement Information System (PROMIS) measures of pain intensity, pain interference, physical function, mobility, mental health, and physical health were compared. Multivariate linear regression was used to assess for confounding comorbid conditions. RESULTS: In univariate analysis, patients with larger BMIs had worse scores for KOOS, JR and all PROMIS metrics preoperatively. Postoperatively, scores for KOOS, JR and PROMIS pain interference, mobility, and physical health were statistically worse in higher BMI groups, though differences were not clinically significant. Morbidly obese patients achieved greater pre/post-Δ improvements in KOOS, JR and global physical health scores. Multivariate regression analysis showed high BMI was independently associated with greater pre/post-Δ improvements in KOOS, JR and global health scores. CONCLUSION: Obese patients report worse preoperative scores for function and health, but greater pre/post-Δ improvements in KOOS, JR and physical health scores following TKA. Quality of life benefits of TKA in obese patients should be a factor when assessing surgical candidacy.

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.

Clinical, Radiographic, and Patient-Reported Outcomes Associated with a Handheld Image-free Robotic-Assisted Surgical System in Total Knee Arthroplasty.

One of the primary aims of total knee arthroplasty (TKA) is restoration of the mechanical axis of the lower limb. Maintenance of the mechanical axis within 3° of neutral has been shown to result in improved clinical results and implant longevity. Handheld image-free robotic-assisted total knee arthroplasty (HI-TKA) is a novel way of performing TKA in the era of modern robotic-assisted TKA. The aim of this study is to assess the accuracy of achieving targeted alignment, component placement, clinical outcomes, as well as patient satisfaction after HI-TKA.

The Benefit in Patient-Reported Outcomes After Total Knee Arthroplasty was Comparable Across Income Quartiles.

BACKGROUND: Few studies have assessed how socioeconomic status (SES) influences patient-reported outcomes (PROMs) after total knee arthroplasty (TKA). This study evaluated the impact of patient median ZIP code income levels on PROMs after TKA. METHODS: We retrospectively reviewed patients at our institution undergoing primary, unilateral TKA from 2017 to 2020. Patients who did not have one-year postoperative PROMs were excluded. Patients were stratified based on the quartile of their home ZIP code median income from United States Census Bureau data. There were 1,267 patients included: 98 in quartile 1 (median income ≤ $46,308) (7.7%); 126 in quartile 2 (median income $46,309-$57,848) (10.0%); 194 in quartile 3 (median income $57,849-$74,011) (15.7%); and 849 in quartile 4 (median income ≥ $74,012) (66.4%). We collected baseline demographic data, 2-year outcomes, and PROMs preoperatively, as well as at 12 weeks and one year, postoperatively. RESULTS: The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was significantly higher in quartile 4 preoperatively (P < .001), 12 weeks postoperatively (P < .001), and one year postoperatively (P < .001). There were no significant differences in delta improvements of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement from preoperative to 12 weeks or one year postoperatively. There were no significant differences in lengths of stay, discharge dispositions, readmissions, or revisions. CONCLUSION: Patients from lower income areas have slightly worse knee function preoperatively and worse outcomes following TKA. However, improvements in PROMs throughout the first year postoperatively are similar across income quartiles, suggesting that patients from lower income quartiles achieve comparable therapeutic benefits from TKA. LEVEL III EVIDENCE: Retrospective Cohort Study.

Accuracy of ICD-10 Coding for Femoral Head Bearing Surfaces in Hip Arthroplasty.

BACKGROUND: The International Classification of Diseases-10 Procedure Code System (ICD-10-PCS) introduced oxidized zirconium (OxZi) and niobium procedural codes to the types of femoral head bearing surfaces in 2017. These codes aimed to increase procedural specificity in coding and improve data collection through administrative claims databases. This study aimed to assess the accuracy of ICD-10-PCS coding for femoral head bearing surfaces (cobalt chrome/metal, ceramic, and OxZi) in hip procedures. METHODS: A retrospective analysis of 6,204 procedures utilizing femoral heads performed between October 1, 2017 and August 26, 2021 at a large, urban academic hospital was conducted. Operative reports and implant logs were queried to determine the femoral head bearing surface, which was used during the total hip arthroplasty. These results were then compared to the ICD-10-PCS codes in the billing records. Coding accuracy was subsequently determined and statistical differences between the three groups were evaluated. RESULTS: The ICD-10-PCS coding was accurate for 90.8% (5,634/6,204) of cases. Coding accuracy for ceramic femoral heads (95.4%, 4,171/4,371) was significantly greater than that of both cobalt chrome/metal (73.7%, 606/822; P < .001) and OxZi (84.8%, 857/1,011; P < .001) femoral heads. CONCLUSION: While coding for ceramic femoral heads was very accurate, OxZi and cobalt chrome/metal femoral heads were miscoded at a rate of approximately 20%. These inaccuracies call for further evaluation of the ICD-10-PCS coding process to ensure that conclusions drawn from clinical research performed through administrative claims databases are not subject to error.