A retrospective comparison of 90-day outcomes, length of stay, and readmissions between robotic-assisted and laparoscopic colectomy.

Investigations generally assess 30 days of perioperative outcomes with robotic-assisted and laparoscopic colectomy. Outcomes beyond 30 days serve as a quality metric of surgical services and an assessment of 90 days of outcomes may have greater clinical utility. The purpose of this study was to assess 90 days of outcomes, length of stay (LOS), and readmissions among patients who underwent a robotic-assisted versus laparoscopic colectomy using a national database. Patients undergoing either robotic-assisted or laparoscopic colectomy were identified using Current Procedural Terminology (CPT) codes within PearlDiver, a national, inpatient records database from 2010 to 2019. Outcomes were defined using the National Surgical Quality Improvement Program (NSQIP) risk calculator and identified using International Classification of Disease (ICD) diagnosis codes. Categorical variables were compared using chi-square tests, and continuous variables were compared using paired t tests. Covariate-adjusted regression models were also constructed to evaluate these associations while accounting for potential confounders. A total of 82,495 patients were assessed in this study. At 90 days, patients of the laparoscopic colectomy cohort experienced a higher rate of complications than patients who underwent robotic-assisted colectomy (9.5 vs. 6.6%, p < 0.001). There were no significant differences in LOS (6 vs. 6.5 days, p = 0.08) and readmissions (6.1 vs. 6.7%, p = 0.851) at 90 days. Patients undergoing robotic-assisted colectomy have a lower risk for morbidity at 90 days. Neither approach is superior for LOS nor 90 days of readmissions. Both techniques are effective minimally invasive procedures, yet patients may gain a greater risk benefit from robotic colectomy.

Primary total hip arthroplasty complications and costs in liver transplant recipients: a matched analysis using a national database.

BACKGROUND: The number of liver transplant recipients (LTR) is worldwide increasing and, as the survival is improving as well, there is an increasing number of patients needing total hip arthroplasty (THA). There might be increased risks for this specific group of patients and due to their comorbidities costs might be higher too. Using a big national database outcome and cost of THA should be compared between liver transplant recipients and the general population. METHODS: The study was performed using a collection of Medicare, Medicaid, and private insurance claims. Length of stay (LOS), 30-day readmissions, complications rates up to 5 years, and 90-day total cost of care between liver transplant recipients and matched non-transplant patients should be compared. All primary THAs from 2010 to 2019 were identified. 513 patients with a liver transplant before their THA were matched to 10,759 patients without a history of solid organ transplant at a 1:20 ratio based on age, sex, Charlson Comorbidity Index, obesity, and diabetes status. RESULTS: LTR had a longer average LOS (4.2 vs. 3.4 days, p < 0.001). There was no difference in the thirty-day readmissions (5.7% vs. 4.1%, p = 0.117) and 90-day dislocation rates (2.9% vs. 2.4%, p = 0.600). Total costs in the first ninety days after THA were not different between the LTR and controls (p = 0.756). CONCLUSIONS: These findings suggest that complications and costs are no major point of concern in patients with liver transplant that are operated with THA.

Quality and readability of online patient information on the left ventricular assist device.

BACKGROUND: As patients seek online health information to supplement their medical decision-making, the aim of this study is to assess the quality and readability of internet information on the left ventricular assist device (LVAD). METHODS: Three online search engines (Google, Bing, and Yahoo) were searched for "LVAD" and "Left ventricular assist device." Included websites were classified as academic, foundation/advocacy, hospital-affiliated, commercial, or unspecified. The quality of information was assessed using the JAMA benchmark criteria (0-4), DISCERN tool (16-80), and the presence of Health On the Net code (HONcode) accreditation. Readability was assessed using the Flesch Reading Ease score. RESULTS: A total of 38 unique websites were included. The average JAMA and DISCERN scores of all websites were 0.82 ± 1.11 and 52.45 ± 13.51, respectively. Academic sites had a significantly lower JAMA mean score than commercial (p < 0.001) and unspecified (p < 0.001) websites, as well as a significantly lower DISCERN, mean score than commercial sites (p = 0.002). HONcode certification was present in 6 (15%) websites analyzed, which had significantly higher JAMA (p < 0.001) and DISCERN (p < 0.016) mean scores than sites without HONcode certification. Readability was fairly difficult and at the level of high school students. CONCLUSIONS: The quality of online information on the LVAD is variable, and overall readability exceeds the recommended level for the public. Patients accessing online information on the LVAD should be referred to sites with HONcode accreditation. Academic institutions must provide higher quality online patient literature on LVADs.

Intra-articular Hip Injections Prior to Total Hip Arthroplasty: Infection and Cost-Related Associations.

Intra-articular injections prior to total hip arthroplasty (THA) have been associated with postoperative infections. The purpose of this study was to determine whether a temporal relationship exists between hip injections prior to THA and infection. Specifically, we asked (1) Do patients who receive hip injections within 3 months of THA have a higher incidence of prosthetic joint infections (PJIs) or surgical site infections (SSIs)? and (2) Do these patients incur higher 90-day costs? Patients with hip injections prior to THA were identified using a national database from 2010 to 2019. Three laterality-specific groups (injection 0 to 3 months, 3 to 6 months, and 6 to 12 months prior to THA)were compared with a matched cohort without prior injection (n=277,841). Primary outcomes included PJIs, SSIs, and costs. Patients who had injections within 3 months of THA had a higher incidence of PJIs at 90 days (5.1% vs 1.6%, P<.01) and 1 year (6.8% vs 2.1%, P<.01), when compared with the matched cohort. They also had a higher incidence of SSIs at 90 days (2.8% vs 1.2%, P<.01) and 1 year (3.7% vs 1.7%, P<.01). Mean costs were 13.7% higher in this injection cohort. Patients who had injections between 3 and 6 months prior to THA had higher incidence and odds of postoperative PJIs at 90 days (2.6% vs 1.6%, P<.04), whereas those with injections beyond 6 months had no differences in PJIs (P≥.46). Patients who receive hip injections within 3 months of undergoing primary THA are at increased risk for postoperative PJIs, SSIs, and higher costs. This study reaffirms guidelines for when to perform THAs in these populations. [Orthopedics. 2023;46(1):19-26.].

Phenotypic Frailty Score Predicts Perioperative Outcomes for Geriatric Total Joint Arthroplasty.

Various assessment tools are often used to predict perioperative morbidity among patients older than 75 years who undergo total joint arthroplasty. Yet, few studies describe the use of phenotypic frailty as a predictor for outcomes. The goal of this study was to assess phenotypic frailty with the Sinai Abbreviated Geriatric Evaluation (SAGE) and compare its utility with established assessment tools used in practice. We specifically asked: (1) Can SAGE predict 30-day outcomes, including postoperative delirium? (2) Can SAGE determine the risk of prolonged hospital length of stay? (3) Is SAGE predictive for 30-day readmissions? (4) Can SAGE determine the risk of discharge to a specialized facility? Patients undergoing total hip arthroplasty and total knee arthroplasty were evaluated with the American Association of Anesthesiologists Physical Status (ASA), Charlson Comorbidity Index (CCI), 5-point Modified Frailty Score (5-FS), and SAGE. Assessment scores were determined for each patient, and every incremental change in score was used to predict the likelihood of perioperative complications. A receiver operating characteristic analysis was also performed to calculate testing sensitivity for each assessment tool. The SAGE scores were more likely to predict 30-day complications (odds ratio [95 CI], 2.21 [1.32-3.70]), postoperative delirium (6.40 [1.78-23.03]), and length of stay greater than 2 days (3.90 [1.00-15.7]) compared with ASA, CCI, and 5-FS values. The SAGE scores were not predictive of readmission (1.77 [0.66-4.72]) or discharge to a specialized facility (1.48 [0.80-2.75]). The SAGE score was a more sensitive predictor (area under the curve, 0.700) for perioperative morbidity compared with ASA (0.638), CCI (0.662), and 5-FS (0.644) values. Therefore, SAGE scores can reliably assess risk of perioperative morbidity and may have better clinical utility than ASA, CCI, and 5-FS values for patients undergoing total joint arthroplasty. [Orthopedics. 2022;45(6):e315-e320.].

Timing and Type of Bariatric Surgery Preceding Total Knee Arthroplasty Leads to Similar Complications and Outcomes.

BACKGROUND: No consensus exists regarding the appropriate timing of bariatric surgery (BS) or the complication profiles between Roux-en-Y Gastric Bypass (RYGB) and sleeve gastrectomy (SG) prior to total knee arthroplasty (TKA). We sought to compare 90-day medical and up to two-year surgical complications and revisions among (1) BS performed 6 months and 1 year prior to TKA; (2) between BS types (RYGB and SG) prior to TKA; and (3) with comparison to 2 non-BS cohorts of morbidly and nonmorbidly obese patients. METHODS: We queried a national database to identify patients undergoing BS (RYGB and SG) prior to TKA from 2010 to 2020. Timing (six-month and one-year intervals) and type of BS (RYGB and SG) were identified. Cohorts without prior BS served as comparators: BMI, kg/m2 > 40 and 20-35. Ninety-day to two-year medical/surgical complications and revisions were assessed. Multivariate regression analyses examined the risk factors for prosthetic joint infections (PJIs) and revisions. RESULTS: The timing of BS (6 months and 1 year) had similar incidences of medical/surgical complications and revisions, with both lower than the BMI > 40 cohort (P < .001). Differences between types of BS were also lower than the BMI > 40 cohort (P < .001). The BMI 20-35 had lower complications and revisions among all cohorts. No differences were observed between BS timing or type as risk-factors for PJIs and revisions. CONCLUSION: Timing (6 months or 1 year prior to TKA) and type of BS shared similar complication profiles, lower than BMI > 40 and higher than BMI 20-35. These findings support a surgeon's decision to proceed with TKA at six months post-BS if indicated.

Outcomes of Total Knee Arthroplasty in Patients With a Prior Contralateral Above-Knee Amputation: A Retrospective Review of a Nationwide Database.

BACKGROUND: Total knee arthroplasty (TKA) in patients with a prior contralateral above-knee amputation (AKA) is uncommon, with limited literature describing the outcomes. We used a national database to compare the outcomes of primary TKA in above-knee amputees and nonamputees. METHODS: A retrospective review of TKA recipients with prior contralateral AKA was performed using the PearlDiver database from 2010 to Q2 of 2019. Subjects and outcomes were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revisions (ICD-9 and ICD-10). Patients were identified and matched at a 1-to-3 ratio with nonamputee (AKA group = 931; nonamputee group = 2792 patients). Perioperative outcomes and length of stay (LOS) were compared at 90 days, 6 months, 1 year, 3 years, and 5 years after TKA. RESULTS: The AKA group had a longer LOS (5.19 vs 3.00, P < .001) and higher overall complications rate (33.8% vs 11.8%). At all studied time intervals, the AKA group had higher periprosthetic infections, revisions, mechanical complications, and respiratory failure (P < .001), as well as surgical site infection, pneumonia, and blood transfusion (P < .05). CONCLUSION: Our study revealed higher overall complications and longer LOS among TKAs in prior contralateral above-knee amputees. Surgeons should evaluate the risks and benefits of performing a TKA on patients with prior contralateral AKA.

Sequentially Irradiated and Annealed Highly Cross-Linked Polyethylene: Linear Vector and Volumetric Wear in Total Hip Arthroplasty at 10 Years.

BACKGROUND: There is a paucity of data on the long-term performance of highly cross-linked polyethylene (HXLPE). Therefore, this study evaluated 10-year 1) functional, 2) radiographic, and 3) surgical outcomes in patients who underwent total hip arthroplasty with sequentially irradiated and annealed HXLPE. METHODS: A retrospective, multicenter study was conducted on patients who underwent primary total hip arthroplasty and received HXLPE polymer (n = 151). Two-dimensional radiographic linear and volumetric wear analyses were quantified using the Martell Hip Analysis software, while functional outcomes were assessed by analyzing postoperative Short-Form-12 (SF-12) Physical and Mental Health Surveys and Harris Hip Scores. Radiographic outcomes included yearly linear (mm/y) and volumetric (mm3/y) wear rates. Surgical outcomes included additional operations and survivorship. RESULTS: SF-12 scores were within 1 standard deviation (SD) of the normal population (SF-12 Physical: 47.0; SF-12 Mental: 52.0), while the Harris Hip Scores of 89.5 was borderline between "good" and "excellent." Total and annual linear wear rates were 0.164 mm (SD: 0.199 mm) and 0.015 mm/y (SD: 0.018 mm/y), respectively. The mean total volumetric wear rate was 141.4 mm3 (SD: 165.0) and 12.6 mm3/y (SD: 14.9 mm3/y) when broken down into a yearly rate. Eleven patients required revisions, resulting in an all-cause polyethylene survivorship of 92.7%, with a polyethylene wear survivorship of 100.0%. CONCLUSIONS: Our results demonstrate clinically undetectable linear and volumetric wear rates after 10 years in those who received the unique sequentially irradiated and annealed HXLPE. Furthermore, high rates of survivorship coupled with low all-cause revision rates illustrate the polymers' capability to potentially increase implant longevity.

Comparing Primary Total Hip Arthroplasty in Renal Transplant Recipients to Patients on Dialysis for End-Stage Renal Disease: A Nationally Matched Analysis.

BACKGROUND: Renal transplants are the most commonly performed solid-organ transplants worldwide. It is unclear whether a kidney transplant is associated with reduced postoperative complications in comparison with patients on dialysis for end-stage renal disease (ESRD). The purpose of this study was to utilize a national database to compare readmissions, complications, and costs associated with primary total hip arthroplasty (THA) between matched renal transplant recipients (RTRs) and patients on dialysis for ESRD. METHODS: Patients with a renal transplant (N = 1,401) and those on dialysis for ESRD (without a transplant) (N = 1,463) prior to being treated with a THA from 2010 to 2019 were identified within the PearlDiver database. RTRs and patients on renal dialysis were frequency-matched 1:1 on the basis of 9 patient characteristics, resulting in 582 patients in each group. Length of hospital stay, readmissions, complication rates up to 2 years, and total costs up to 1 year were compared between the groups using chi-square and multivariable logistic regression analyses to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Patients on renal dialysis had an increased mean length of stay (6.3 days) compared with RTRs (4.6 days, p < 0.01). After adjusting for age, tobacco use, and diabetes, patients on renal dialysis were more likely to be readmitted by 90 days (OR = 1.59; CI = 1.11 to 2.29, p < 0.01) and have mechanical complications (OR = 2.13; CI = 1.08 to 4.45, p = 0.03) and revisions (OR = 2.14; CI = 1.14 to 4.01, p = 0.01) by 2 years. Patients on renal dialysis were also more likely to have periprosthetic joint infections at 1 year (OR = 1.91; CI = 1.02 to 3.71, p = 0.04). Patients on dialysis incurred 14% higher costs at 1 year (p = 0.11). CONCLUSIONS: Patients on renal dialysis had more readmissions, complications, and costs after THA when compared with RTRs. Specifically, patients on renal dialysis were more likely to have longer index lengths of stay, more readmissions by 90 days, and more mechanical complications and revision surgery by 2 years. Patients on dialysis also incurred higher costs and had greater odds of PJI. These results suggest that joint surgeons may consider delaying THA in suitable patients until after renal transplantation to reduce postoperative complications and costs. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

THAs Performed Within 6 Months of Clostridioides difficile Infection Are Associated with Increased Risk of 90-Day Complications.

BACKGROUND: Clostridioides difficile infection (CDI) may be a surrogate for poor patient health. As such, a history of CDI before THA may be used to identify patients at higher risk for postoperative CDI and complications after THA. Investigations into the associations between CDI before THA and postoperative CDI and complications are lacking. QUESTIONS/PURPOSES: We compared the (1) frequency and potential risk factors for CDI after THA, (2) the frequency of 90-day complications after THA in patients with and without a history of CDI, and (3) the length of stay and frequency of readmissions in patients experiencing CDIs more than 6 months before THA, patients experiencing CDIs in the 6 months before THA, and patients without a history of CDI. METHODS: Patients undergoing primary THA from 2010 to 2019 were identified in the PearlDiver database using ICD and Current Procedural Terminology codes (n = 714,185). This analysis included Medicare, Medicaid, and private insurance claims across the United States with the ability to perform longitudinal and costs analysis using large patient samples to improve generalizability and reduce error rates. Patients with a history of CDI before THA (n = 5196) were stratified into two groups: those with CDIs that occurred more than 6 months before THA (n = 4003, median 2.2 years [interquartile range 1.2 to 3.6]) and those experiencing CDIs within the 6 months before THA (n = 1193). These patients were compared with the remaining 708,989 patients without a history of CDI before THA. Multivariable logistic regression was used to evaluate the association of risk factors and incidence of 90-day postoperative CDI in patients with a history of CDI. Variables such as antibiotic use, proton pump inhibitor use, chemotherapy, and inflammatory bowel disease were included in the models. Chi-square and unadjusted odds ratios with 95% confidence intervals were used to compare complication frequencies. A Bonferroni correction adjusted the p value significance threshold to < 0.003. RESULTS: Prior CDI during either timespan was associated with higher unadjusted odds for postoperative CDI (CDI > 6 months before THA: OR 8.44 [95% CI 6.95 to 10.14]; p < 0.001; CDI ≤ 6 months before THA: OR 49.92 [95% CI 42.26 to 58.54]; p < 0.001). None of the risk factors included in the regression were associated with increased odds for postoperative CDI in patients with preoperative history of CDI. Patients with a history of CDI before THA were associated with higher unadjusted odds for every 90-day complication compared with patients without a history of CDI before THA. CDI during either timespan was associated with longer lengths of stay (no CDI before THA: 3.8 days; CDI > 6 months before THA: 4.5 days; CDI ≤ 6 months before THA: 5.3 days; p < 0.001) and 90-day readmissions (CDI > 6 months before THA: OR 2.21 [95% CI 1.98 to 2.47]; p < 0.001; CDI ≤ 6 months before THA: OR 3.39 [95% CI 2.85 to 4.02]; p < 0.001). CONCLUSION: Having CDI before THA was associated with higher odds of postoperative CDI compared with patients without a history of CDI. A history of CDI within the 6 months before THA was associated with the greatest odds for postoperative complications and readmissions. Providers should strongly consider delaying THA until 6 months after CDI, if possible, to provide adequate time for patient recovery and eradication of infection. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Effect of Modern Antiretroviral Therapy on Complication Rates After Total Hip Arthroplasty.

BACKGROUND: Antiretroviral therapy (ART) remains the cornerstone of decreasing morbidity and mortality in patients with human immunodeficiency virus (HIV), but additional information on its impact on total hip arthroplasty (THA) complication rates is needed to mitigate risks postoperatively. Therefore, we sought to examine patients with HIV who were and were not taking ART compared with a cohort without HIV in the setting of primary THA with respect to the following outcomes: length of stay, readmissions, and postoperative infection. METHODS: A retrospective database review was performed with PearlDiver for patients who underwent THA from 2010 to 2019 (n = 729,101). Patients with HIV who were and were not taking ART were then identified and were matched with patients without HIV at a 1:1:1 ratio based on age, sex, Charlson Comorbidity Index, diabetes, obesity, and tobacco use, resulting in 601 patients in each cohort. Length of stay, 30-day readmissions, and complications at 90 days and 1 year were analyzed. Continuous outcomes were measured via Student t tests, and categorical outcomes were measured via chi-square analyses. RESULTS: Patients with HIV who were and were not taking ART were found to have similar lengths of stay compared with patients without HIV (range, 4.1 to 4.3 days). Readmission rates were slightly higher in patients with HIV who were taking ART at 4.2% (odds ratio [OR], 1.96 [95% confidence interval (CI), 0.99 to 3.87]) and patients with HIV who were not taking ART at 3.5% (OR, 1.63 [95% CI, 0.81 to 3.30]) compared with patients without HIV at 2.1%. Periprosthetic joint infection rates at 1 year were slightly higher among patients with HIV who were not taking ART at 5.3% (OR, 1.41 [95% CI, 0.82 to 2.45]) compared with patients with HIV who were taking ART at 4.2% (OR, 1.09 [95% CI, 0.61 to 1.94]) and patients without HIV at 3.8%. CONCLUSIONS: Patients with HIV who are and are not taking ART are approaching normalization to the general population in the setting of THA. It is important to note that, although complications may have been mitigated by modern therapy, extreme care should be taken while clinically evaluating these patients prior to the surgical procedure given the complexity of their clinical status. The findings of this study underscore the utility of ART and patient optimization to reduce risk in this patient population. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Impact of Robotic Assisted Surgery on Outcomes in Total Hip Arthroplasty.

BACKGROUND: The introduction of robotic technologies into the field of arthroplasty ushered in promises of increased precision and superior outcomes over conventional methods. However, the effect on outcomes in total hip arthroplasty (THA) remains debatable, particularly when considering the additional financial burden created by the addition of robotics. The purpose of this study is to examine total cost of care, length of stay (LOS), and postoperative complications in robotic-assisted vs conventional THA recipients. MATERIALS AND METHODS: A retrospective review of the Mariner database was performed within PearlDiver Technologies for patients undergoing THA from 2010 to 2018 (n = 714,859). Patients with robotic-assisted procedures were matched with patients undergoing conventional THA at a 1:1 ratio based on age, sex, Charlson Comorbidity Index, smoking, and obesity status (n = 4630). LOS, total cost of care, readmission rates, and medical and surgical outcomes were examined. RESULTS: Robotic-assisted patients had shorter average LOS (3.4 vs 3.7 days, P = .001). The mean cost for robotic-assisted patients was $1684 and $1759 less at 90 days and 1 year, respectively (both P = .001). Readmission rates were higher for robotic-assisted patients at 1 year (7.8 vs 6.6%; P = .001), while surgical outcomes were not significantly different at all timepoints (all P > .498). Robotic-assisted patients demonstrated significantly higher blood transfusion rates (4.4 vs 3.2%; P = .001). CONCLUSIONS: Robotic-assisted THA was associated with minimal decreases in LOS and costs as compared to conventional methods. However, robotics was associated with slightly higher readmissions and blood transfusions.

How Does Conversion Total Hip Arthroplasty Compare to Primary?

BACKGROUND: Recent institutional evidence suggests that conversion total hip arthroplasty (THA) incurs higher complication rates and costs when compared to primary THA. These findings contrast with the current reimbursement system as conversion and primary THAs are classified under the same diagnosis-related group. Thus, a national all-payer database was utilized to compare complication rates up to 2 years, 30-day readmission rates, and 90-day costs between conversion THA and matched primary THA patients. METHODS: A retrospective review of the PearlDiver database between 2010 and second quarter of 2018 was performed using Current Procedural Terminology (CPT) codes to compare conversion THA (CPT 27132) to primary THA (CPT 27130). Patients were matched at a 1:3 ratio based on age, gender, Charlson Comorbidity Index, body mass index, tobacco use, and diabetes (conversion = 8369; primary = 25,081 patients). RESULTS: Conversion THA had higher rates of periprosthetic joint infections (conversion: 7.7% vs primary: 1.4%), hip dislocations (4.5% vs 2.0%), blood transfusions (2.0% vs 1.0%), mechanical complications (5.5% vs 1.0%), and revision surgeries (4.0% vs 1.5%) (P < .001 for all) by 90 days. The 30-day readmission rate for conversion THA was significantly higher compared to the primary group (7.3% vs 3.3%) (P < .001). Median cost at 90 days for conversion THA was significantly higher compared to primary THA ($18,800 vs $13,611, P < .001). CONCLUSION: This study revealed increased complication rates, revisions, readmissions, and costs among conversion THA patients compared to matched primary THA patients. These results support the reclassification of conversion into a diagnosis-related group separate from primary THA.

Osteoarthritis and Osteonecrosis in Total Hip Arthroplasty: 90-Day Postoperative Costs and Outcomes.

BACKGROUND: Two common diagnoses for patients undergoing total hip arthroplasty (THA) are osteoarthritis (OA) and osteonecrosis (ON), pathologically different diseases that affect postoperative complication rates. The underlying pathology of ON may predispose patients to a higher rate of certain complications. Previous research has linked ON with higher mortality and revisions, but a comparison of costs and complication rates may help elucidate further risks. This study reports 90-day costs, lengths of stay (LOS), readmission rates, and complication rates between patients undergoing THA for OA and ON. METHODS: The Nationwide Readmissions Database was retrospectively reviewed for primary THAs, with 90-day readmissions assessed from the index procedure. Patients diagnosed with OA (n = 1,577,991) and ON (n = 55,034) were identified. Costs, LOS, and any readmission within 90 days for complications were recorded and analyzed with the chi-square and t-tests. RESULTS: Patients with ON had higher 90-day costs ($20,110.80 vs. 22,462.79, P < .01) and longer average LOS (3.48 vs. 4.49 days, P < .01). Readmission rates within 90 days of index THA were significantly higher among patients with ON (7.7% vs. 13.1%, P < .01). Patients with OA had a lower incidence of 90-day overall complications (4.1 vs. 6.4%, P < .01). CONCLUSIONS: Patients undergoing THA for ON incur higher readmission-related costs and complication rates. Understanding the predisposing factors for increased complications in ON may improve patient outcomes.