Complication rates after hip or knee arthroplasty in morbidly obese patients

Body Mass Index as a Risk Factor for Readmission Rates in Direct Anterior Approach Total Hip Arthroplasty

Background

Multiple studies have examined the relationship between obesity and increased risk of perioperative complications in patients undergoing total hip arthroplasty (THA). The purpose of this study was to compare the rate of perioperative complications stratified by body mass index (BMI) in patients undergoing THA through a direct anterior (DA) approach.

Methods

A retrospective review at a single high-volume orthopaedic specialty hospital identified all DA THAs performed between January 2019 and August 2022. Patients were stratified by BMI into the following cohorts: underweight (BMI<18.5), normal (BMI = 18.5-25), overweight (BMI = 25-30), obese class I (BMI = 30-35), obese class II (BMI = 35-39.9), and obese class III (BMI ≥ 40). Primary outcomes collected included 30-day and 90-day readmissions, emergency department visits, intraoperative fracture, and 90-day infection requiring return to the operating room. There were 4767 patients with a mean BMI of 28 kg/m2 (15.5-54.5) and a mean age of 67 years (18-100 years).

Results

Thirty-day readmission rates in the obese class III (6.2%) were significantly higher when compared individually to all other cohorts (P < .001). Additionally, logistic regression found that underweight patients had an increased likelihood of an intraoperative fracture (odds ratio [OR]: 13.120, 95% confidence interval [CI]: 1.172-146.930, P < .001), and both obese classes I and III were more likely to have a 90-day infection that required a return to the operating room (OR: 8.508, 95% CI: 1.023-70.779, P < .001 and OR: 29.853, 95% CI: 2.683-332.187, P < .001, respectively).

Conclusions

Obese class III patients have a higher rate of 30-day readmission following DA THA than all other BMI cohorts and are at increased risk of infection requiring return to the operating room when compared to patients with normal BMI. Surgeons should counsel patients regarding the increased potential complication risks related to BMI.

The safety and efficacy of outpatient total hip arthroplasty in very obese patients

Aims

As the number of patients who undergo total joint replacement as an outpatient continues to increase, it is essential that the safety and efficacy of this form of treatment is maintained. The aim of this study was to examine the outcome in a series of very obese patients who underwent total hip arthroplasty (THA) as an outpatient.

Methods

A prospective database was used to identify 381 patients who underwent THA as an outpatient. Using case-control matching based on age, sex, and American Society of Anesthesiologists grade, 51 very obese patients with a BMI > 35 kg/m2 were matched to 51 patients with a BMI < 35 kg/m2 who underwent THA as an outpatient. In a subsequent analysis, 47 patients (41 THAs) from the same very obese cohort were matched to 47 very obese patients who underwent THA as an inpatient. For each group, readmission within 90 days, return to the emergency department (ED) within 90 days, adverse events, and reoperations were recorded.

Results

The mean BMI of the very obese outpatient group was 40 kg/m2 (35 to 55); their mean age was 61 years (38 to 78). The mean BMI of the outpatients with a BMI < 35 kg/m2 was 27 kg/m2 (17 to 34); their mean age was 61 years (33 to 78). The mean BMI of the very obese inpatient group was 40 kg/m2 (35 to 55); their mean age 62 years (34 to 77). Between the two outpatient groups, the rate of adverse events was significantly higher in the very obese group (15.69% compared with 1.96% (p = 0.015)). The reoperation rate was also significantly higher in the very obese group (five cases compared with none; p = 0.022). The rate of readmission and return to the ED within 90 days did not differ significantly between the groups (p = 0.299 and p = 0.092, respectively). There was no significant difference for all outcomes between the very obese patients who were treated as an outpatient and those who were treated as an inpatient.

Conclusion

The very obese group had significantly higher rates of adverse events and reoperations compared with those with a BMI < 35 kg/m2, but there was no difference when they were compared with a matched cohort of very obese patients who were treated as an inpatient. Caution must always be taken to identify the ideal candidates for outpatient surgery. However, BMI should not be used as a sole variable for deciding whether THA should be undertaken as an inpatient.

Advantages in orthopaedic implant infection diagnostics by additional analysis of explants

PURPOSE

Implant-associated infections are the most challenging complication in orthopaedics and trauma surgery as they often lead to long courses of illness and are a financial burden for the healthcare system. There is a need for fast, simple, and cheap identification of pathogens but the ideal detection method was not found yet. The work aims to test whether the detection of pathogens culturing the removed implant is more successful than from simultaneously taken tissue samples or punction fluid.

METHODS

Implants were removed due to infection, irritation, or loosening. Tissue samples and joint fluids were processed for bacterial growth in sterile conditions. Samples were incubated and checked for growth. Bacterial identification and antibiotic sensitivity testing were performed. Data were anonymized, and statistical analysis was done using Excel and SAS, employing tests like Shapiro-Wilk, Mann-Whitney-U, and Kruskal-Wallis. Ethical approval was obtained for this study.

RESULTS

Between February 2018 and April 2019, a total of 163 patients (175 cases) underwent orthopaedic implant removal for various reasons. 30 cases were not usable or analyzable due to missing or damaged reference material, so 145 cases could be evaluated due to study protocol. The range of detected bacteria was as expected and included low-virulent bacteria such as Micrococcus luteus and Corynebacteria. Pathogen detection by culture of the the explant´s was more sensitive (84.83%) than pathogen detection from tissue samples and punction fluid (64.14%, p<0.0001). Comorbidities did not play any role in the quality of detection but prior antibiotic treatment did influence the results of tissue diagnostics.

CONCLUSION

This study showed with a higher frequency of bacterial detection of orthopedic explant´s surface compared to tissue samples or punction fluid. This may reduce the number of samples and cost but enhances the quality of orthopaedic implant-related infection diagnostics.

Measurement of periarticular subcutaneous fat on CT images and adverse outcomes following total knee arthroplasty

Background

Obesity is associated with a higher rate of wound complications following primary total knee arthroplasty (TKA). With readily available computer tomography (CT) images from robotic-assisted TKA, we analyzed measurement of fat content on preoperative CT images as a possible predictor of wound complications following primary TKA.

Methods

Patients who underwent robotic-assisted TKA at one institution in 2018 were included in this retrospective cohort study. Two independent reviewers measured three SCF areas at different axial CT cuts and normalized them by dividing the area of the distal femur. These areas were distributed into 4 groups. Any wound complication that required clinical or surgical intervention was reviewed and analyzed. For further comparison, prepatellar SCF thickness ratio measured on CT scan and BMI were grouped and analyzed similarly for wound complications. We also analyzed any association of SCF measurement with secondary outcomes such as operative time, length of stay, readmission, and reoperation.

Results

One hundred fifty patients with diagnosis of osteoarthritis, mean age of 64 years and BMI of 34.3 kg/m2 were included in this study. Ninety-one patients (61 %) were female. Normalized SCF measurements at 2 cm above the patella, mid-patella, and tibial tubercle had excellent intraclass correlation coefficient at 0.987, 0.989, and 0.989, respectively. When SCF at 2 cm above patella was analyzed, Group 1 (smallest amount of SCF) had a significantly higher wound complication rate compared with Groups 2 and 3 combined (18.9 vs 5.3 %, p = 0.036). Group 4 (largest amount of SCF) also had a significantly higher wound complication rate compared with Groups 2 and 3 combined (18.9 vs 5.3 %, p = 0.036).

Conclusions

Accurate and consistent measurement of periarticular fat around the knee based on axial CT images demonstrated that moderate amount of fat is associated with better clinical outcomes following primary TKA. Our study did not find any clinical significance of gender difference in fat distribution. Therefore, more studies should be undertaken to evaluate for any clinical association of gender-specific fat distribution and to confirm our finding that a certain amount of fatty tissue is necessary for improved outcomes following TKA.

Higher Pulmonary Embolism Risk in Morbidly Obese Patients on Aspirin Monotherapy after Total Knee Arthroplasty: A Claims Database Analysis

BACKGROUND

Aspirin is the most common drug used for venous thromboembolism (VTE) prophylaxis after total knee arthroplasty (TKA). Morbid obesity is a potential risk factor for VTE, prompting some to use stronger anticoagulants. However, there are no established guidelines for VTE prevention in obese or morbidly obese patients undergoing primary TKA.

METHODS

Using a national administrative claims database, patients who underwent primary TKA were divided into the following three cohorts based on body mass index (BMI): < 30, 30 to 39.9, or ≥ 40. Each patient had a prescription claim for aspirin, but no other prophylaxis agents within 3 days after the index procedure. We assessed deep vein thrombosis (DVT) and pulmonary embolism (PE) incidence at 90 and 180 days postoperatively. Secondary outcomes included wound dehiscence; hematoma; periprosthetic joint infection; and debridement, antibiotics, and implant retention or explantation procedures. We included 20,097 patients, of whom 4,277 (21%), 10,663 (53%), and 5,157 (26%) had a BMI < 30, 30 to 39.9, and ≥ 40, respectively.

RESULTS

In the multivariable analysis, there was no difference in the incidence of DVT or PE within 90 or 180 days after surgery for the BMI 30 to 39.9 compared to the BMI < 30 cohort. However, the incidence of PE within 90 days after surgery was higher in the BMI ≥ 40 cohort (odds ratio: 2.74), an effect that disappeared by 180 days. There was a higher adjusted odds of debridement, antibiotics, and implant retention procedures in the BMI ≥ 40 compared to the BMI < 30 cohort; otherwise, the incidence of secondary outcomes did not differ by BMI.

CONCLUSIONS

When aspirin was used as a standardized monotherapy for VTE prophylaxis following primary TKA, there was an increased 90-day incidence of PE in morbidly obese patients but no difference in DVT or PE incidence in obese patients.

Effect of body mass index on complications following total shoulder arthroplasty: a population-wide analysis

BACKGROUND

Evidence regarding the effect of body mass index (BMI) on complications following anatomic shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (rTSA) remains controversial. This high-powered study examines the effect of BMI on surgical and medical complications following aTSA and rTSA.

METHODS

This retrospective cohort study was conducted using the Premier Healthcare Database to query all adult patients who underwent primary, elective TSA (aTSA, rTSA) from 2016 to 2020. Patients eligible for inclusion were identified using International Classification of Diseases -10 and CPT codes for primary TSA. Patients were stratified into 3 subgroups based on BMI (BMI <30 kg/m2, BMI 30-35 kg/m2, BMI >35 kg/m2). The primary endpoints assessed were 90-day risks of postoperative complications, revisions, and readmissions among the 3 BMI groups undergoing primary TSA.

RESULTS

A total of 32,645 patients were analyzed; 10,951 patients underwent aTSA and 21,694 patients underwent rTSA. Patient populations for aTSA and rTSA differed significantly across all BMI categories in terms of age, sex, cost of care, and insurance status. After multivariate regression analysis, there was no increased risk of surgical complications in the aTSA and rTSA cohorts with BMI 30-35 kg/m2 and BMI >35 kg/m2. In the aTSA cohort, rates of acute respiratory failure (adjusted Odds Ratio [aOR] 2.65) was all significantly higher in the BMI >35 kg/m2 group. As for rTSA cohort, acute respiratory failure (aOR 1.67) and acute renal failure (aOR 1.53) were significantly higher in the BMI >35 kg/m2 group.

CONCLUSION

While we found no increased risk of immediate postoperative surgical risks, patients with a BMI >35 kg/m2 demonstrated greater risk of medical complications after rTSA. Given this trend, providers should exercise caution in patient selection for TSA and counsel obese patients as to these increased risks. Future studies should aim to provide a more comprehensive picture of the effect of BMI on functional outcomes after TSA.

Elevated body mass index and obesity are associated with pain-associated psychological distress in patients with hip pain

INTRODUCTION

Little research has investigated the relationship between musculoskeletal pain and body mass index (BMI) in the context of pain-associated psychological distress. This study aims to determine if independent associations exist between BMI, obesity, demographic variables, and psychological distress in patients presenting with hip pain.

MATERIALS AND METHODS

Using a retrospective cross-sectional study design, 428 patients completed the Optimal Screening for Prediction of Referral and Outcome Yellow Flag (OSPRO-YF) and were categorized into pain-associated psychological distress phenotypes using latent class analysis. Participants were stratified into five BMI categories outlined by the Centers for Disease Control and Prevention (CDC) using descriptive statistics. Multinomial logistic regression was employed to determine a relationship between psychological distress phenotype and BMI (first as a continuous variable, then as a categorical variable), age, gender, race, and veteran status as candidate variables.

RESULTS

Four psychological distress phenotypes were generated: high distress (n = 172, 40.2%), low distress (n = 114, 26.6%), negative pain coping (n = 98, 22.9%), and low self-efficacy and acceptance (n = 44, 10.3%). BMI analyses identified 4 participants (0.9%) as being underweight (BMI < 18.5), 146 participants (34.1%) with recommended weights (18.5 < BMI < 24.9), 133 (31.1%) as overweight (25 < BMI < 29.9), 113 (26.4%) with obesity (30 < BMI < 39.9), and 32 (7.5%) with severe obesity (BMI > 40). Additionally, 54.0% of participants with obesity and 59.4% of participants with severe obesity had high psychological distress. As a continuous and categorical variable, elevated BMI was independently associated with membership in the high distress phenotype (p < 0.001). The overweight (p = 0.043), obesity (p < 0.001), and severe obesity (p = 0.034) subgroups and Black/African American participants (p = 0.020) were also all significantly associated with high distress.

CONCLUSIONS

Elevated BMI and obesity are associated with high psychological distress in patients with hip pain. These results may inform operative, nonoperative, and behavioral health treatment pathways for patients with comorbid obesity and hip pain, as well as provide direction for prospective studies to address obesity and psychological distress among patients with musculoskeletal pain.

Relationship between soft tissue envelope thickness of the lower extremity and acute periprosthetic joint infection of the knee

BACKGROUND

The prevalence of obesity is increasing worldwide and it is known to be associated with many postoperative complications, including infection. Patients' body fat distribution may vary and body mass index (BMI) does not provide sufficient information about adipose tissue thickness of the lower extremities. The aim of this study is to investigate the relationship between thigh diameters and early postoperative prosthesis-related joint infections (PJI) in patients who underwent arthroplasty.

METHODS

The study included 76 patients and 114 knees who were operated on by a single surgeon and underwent total knee arthroplasty (TKA) due to primary knee osteoarthritis between May 2022 and September 2023 in a tertiary reference hospital. Circumference of the thickest part of the operated thigh (cm), preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels, height, weight, BMI and the presence of early postoperative prosthesis-related joint infections were evaluated.

RESULTS

The mean BMI was 32.6 ± 4.2 (kg/m2). Two (2.6%) were normal weight, 14 (18.5%) were overweight, 58 (76.3%) were obese and 2 (2.6%) were morbidly obese. The mean circumference of the thickest part of the thigh was 57.56 ± 6.38 (cm). 6 patients were diagnosed with PJI in the acute phase. The mean circumference of the thickest part of the thigh was statistically significantly greater in the group with acute PJI compared to the group without PJI (p = 0.048).

CONCLUSION

The incidence of acute PJI was found to be significantly higher in patients with larger thigh diameters, whereas no such relationship was observed for BMI. The incorporation of preoperative soft tissue envelope measurements into routine clinical examination may prove beneficial in reducing the risk of PJI.

The Use of Aspirin for Venous Thromboembolism Prophylaxis in Patients Who Have Morbid Obesity Undergoing Primary and Revision Total Joint Arthroplasty

BACKGROUND

Venous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index (BMI) > 40 undergoing primary and revision total joint arthroplasty, and second, to investigate aspirin (ASA) efficacy and safety.

METHODS

We identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision total joint arthroplasty from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any VTE event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively.

RESULTS

The total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = .669). The VTEs consisted of 6 deep venous thromboses (DVTs), 14 pulmonary embolisms, and one concomitant deep venous thrombosis and pulmonary embolism. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant (AC) 0.5% (n = 6), and AC alone 0.4% (n = 5) (P = .954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + AC, or AC alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = .351).

CONCLUSIONS

The use of aspirin 325 and 81 mg was found to have similar VTE rates as aspirin + ACs and ACs alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE.

Association Between Body Mass Index and Clinical Outcomes of Gender-Affirming Masculinizing Chest Reconstruction

INTRODUCTION

Body mass index (BMI) is often used in surgical settings to determine patients' risk of complications. In the context of gender-affirming care, BMI requirements for surgery can limit access to necessary care for larger-bodied people. There is a critical need to understand the association between BMI and postoperative outcomes for this population.

METHODS

A retrospective chart review was conducted using the first 250 consecutive gender-affirming masculinizing chest reconstructions performed between 2017 and 2021 at a large academic medical institution. The relationships between BMI, preoperative factors, and common postsurgical outcomes were assessed.

RESULTS

Average BMI at surgery was 27.5 ± 6.7 kg/m2. Increases in BMI were associated with longer drain stays, larger volume of tissue resected, higher likelihood of nipple grafts, and lower likelihood of periareolar surgery (all P < 0.0001). Simple logistic regression revealed that BMI increases were significantly related to the likelihood of experiencing dog ears in the intermediate term (P = 0.002). Multivariate logistic regression adjusted for common covariates (age, ethnicity, smoking status, asthma, autoimmune disorders, cardiovascular conditions, and mental health disorders) did not reveal any significant relationships between BMI and the likelihood of experiencing complications at any study point.

CONCLUSIONS

Masculinizing chest reconstruction is safe and satisfactory for young adult patients across the range of BMI, with significant differences in outcomes found only for esthetic complications (i.e., dog ears). Surgeons should inform patients with higher BMIs about what outcomes to expect but higher BMI should not preclude surgery access.

Severe obesity in total knee arthroplasty occurs in younger patients with a greater healthcare burden and complication rate

BACKGROUND

Knee osteoarthritis in the presence of severe obesity (BMI ≥ 40) is becoming an increasing presentation to healthcare services. When progressing to arthroplasty, this group is known to have higher complication rates.

METHOD

A retrospective cohort study at a tertiary referral centre (UK) with all sequential patients undergoing TKA between 2019 and 2020 included following identification from the UK National Joint Registry. Patients were divided by BMI < 40 and BMI ≥ 40 (86, 16.3%). Analysis of BMI with pre-operative parameters including age, ASA, and blood parameters was performed. Primary outcome was re-operation rate. Secondary outcomes included length of stay, complications, and re-admission.

RESULTS

Five hundred and twenty-eight sequential TKA patients were included. The BMI < 40 group (442 patients, 83.7%) were mean 5.4 years younger (p < 0.001), had a higher ASA grade (p < 0.001) lower albumin (p < 0.001) and higher HbA1c (p < 0.001) than the BMI ≥ 40 group (86 patients, 16.3%). The BMI ≥ 40 group had a higher rate of re-operation (8% vs 2%, p = 0.012), and longer length of stay (mean 1.2 days longer p < 0.001), most commonly due to wound discharge, which alongside dehiscence was significantly higher (11.6% vs 4.3% p = 0.02). Overall, re-admission rates were also higher (18.6% vs 6.1% p = 0.06) with wound dehiscence, superficial infection, and deep infection the most common causes.

CONCLUSIONS

Those patients undergoing TKA with a BMI ≥ 40 are younger and have higher reoperation rates, greater length of stay, higher re-admission rates and more postoperative complications, providing a target for the development of pre-operative optimisation programmes.

Are Patients With Morbid Obesity at Increased Risk of Pulmonary Embolism or Proximal Deep Vein Thrombosis After Lower Limb Arthroplasty? A Large-database Study

BACKGROUND

Whether increased BMI is associated with an increased risk of venous thromboembolism (VTE) is controversial. Despite this, BMI > 40 kg/m 2 remains a common cutoff for lower limb arthroplasty eligibility. Current United Kingdom national guidelines list obesity as a risk factor for VTE, but these are based on evidence that has largely failed to differentiate between potentially minor (distal deep vein thrombosis [DVT]), and more harmful (pulmonary embolism [PE] and proximal DVT) diagnoses. Determining the association between BMI and the risk of clinically important VTE is needed to improve the utility of national risk stratification tools.

QUESTIONS/PURPOSES

(1) In patients undergoing lower limb arthroplasty, is BMI 40 kg/m 2 or higher (morbid obesity) associated with an increased risk of PE or proximal DVT within 90 days of surgery, compared with patients with BMI less than 40 kg/m 2 ? (2) What proportion of investigations ordered for PE and proximal DVT were positive in patients with morbid obesity who underwent lower limb arthroplasty compared with those with BMI less than 40 kg/m 2 ?

METHODS

Data were collected retrospectively from the Northern Ireland Electronic Care Record, a national database recording patient demographics, diagnoses, encounters, and clinical correspondence. Between January 2016 and December 2020, 10,217 primary joint arthroplasties were performed. Of those, 21% (2184 joints) were excluded; 2183 were in patients with multiple arthroplasties and one had no recorded BMI. All 8033 remaining joints were eligible for inclusion, 52% of which (4184) were THAs, 44% (3494) were TKAs, and 4% (355) were unicompartmental knee arthroplasties; all patients had 90 days of follow-up. The Wells score was used to guide the investigations. Indications for CT pulmonary angiography for suspected PE included pleuritic chest pain, reduced oxygen saturations, dyspnea, or hemoptysis. Indications for ultrasound scans for suspected proximal DVT included leg swelling, pain, warmth, or erythema. Distal DVTs were recorded as negative scans because we do not treat them with modified anticoagulation. The division of categories was set at BMI 40 kg/m 2 , a common clinical cutoff used in surgical eligibility algorithms. Patients were grouped according to WHO BMI categories to assess for the following confounding variables: sex, age, American Society of Anesthesiologists grade, joint replaced, VTE prophylaxis, grade of operative surgeon, and implant cement status.

RESULTS

We found no increase in the odds of PE or proximal DVT in any WHO BMI category. When comparing patients with BMI less than 40 kg/m 2 with those with a BMI of 40 kg/m 2 or higher, there was no difference in the odds of PE (0.8% [58 of 7506] versus 0.8% [four of 527]; OR 1.0 [95% CI 0.4 to 2.8]; p > 0.99) or proximal DVT (0.4% [33 of 7506] versus 0.2% [one of 527]; OR 2.3 [95% CI 0.3 to 17.0]; p = 0.72). Of those who received diagnostic imaging, 21% (59 of 276) of CT pulmonary angiograms and 4% (34 of 718) of ultrasounds were positive for patients with BMI less than 40 kg/m 2 compared with 14% (four of 29; OR 1.6 [95% CI 0.6 to 4.5]; p = 0.47) and 2% (one of 57; OR 2.7 [95% CI 0.4 to 18.6]; p = 0.51) for patients with BMI 40 kg/m 2 or higher. There was no difference in the percentage of CT pulmonary angiograms ordered (4% [276 of 7506] versus 5% [29 of 527]; OR 0.7 [95% CI 0.5 to 1.0]; p = 0.07) or ultrasounds ordered (10% [718 of 7506] versus 11% [57 of 527]; OR 0.9 [95% CI 0.7 to 1.2]; p = 0.49) for BMI less than 40 kg/m 2 and BMI 40 kg/m 2 or higher.

CONCLUSION

Increased BMI should not preclude individuals from lower limb arthroplasty based on suspected risk of clinically important VTE. National VTE risk stratification tools should be based on evidence assessing clinically relevant VTE (specifically, proximal DVT, PE, or death of thromboembolism) only.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Trends in prescribing and outcomes in obese versus non-obese patients receiving rivaroxaban therapy: an observational study using real-world data

PURPOSE

To investigate real-world prescribing trends and clinical outcomes based on body mass index (BMI) categorization in patients who received rivaroxaban therapy.

METHODS

This was a retrospective cohort study involving all patients who received rivaroxaban therapy across all Hamad Medical Corporation (HMC) hospitals from 2015 to 2020.

RESULTS

The number of patients initiated on rivaroxaban therapy significantly increased from 152 (3.3%) in 2015 to 1342 (28.9%) in 2020 (p <0.001). Within BMI categories, a similar increasing trend was observed in underweight, normal, and overweight patients, while from 2018 to 2020, there was a decreasing trend in rivaroxaban prescribing in all obese classes. The prevalence rate of all-cause mortality differed significantly between the BMI groups, with the highest mortality being among morbidly obese patients (BMI ≥ 40 kg/m2) (p< 0.001). On the other hand, no significant differences were found between the BMI groups in terms of bleeding, pulmonary embolism, deep vein thrombosis and stroke incidences. Multivariate logistic regression analyses showed that the likelihood of all-cause mortality was significantly higher in overweight and all categories of obese patients compared to underweight patients: overweight (OR: 5.3, 95% CI: 2.3-11.9, p< 0.001); obese class 1 (OR: 5.4, 95% CI: 2.3 - 12.2, p< 0.001); obese class 2 (OR: 6.5, 95% CI: 2.7 - 15.6, p< 0.001); and obese class 3 (OR: 3.7, 95% CI: 1.6 - 8.7, p = 0.003).

CONCLUSIONS

Rivaroxaban prescribing has significantly increased over the years across general population, with a noticeable decline in obese population during the last few years (from 2018 onwards). Furthermore, an appreciable association was evident between all-cause mortality and BMI of these patients.

The Influence of Patient Sex on Outcomes Following One-Stage and Two-Stage Revision for Periprosthetic Joint Infection in Total Joint Arthroplasty

Although females have a higher rate of primary total joint arthroplasty (TJA), males have a higher rate of revision. The literature lacks studies examining the relationship between sex and outcomes following single and two-stage exchange for periprosthetic joint infection (PJI). The purpose of this study was to examine if differences exist in outcomes following revision for chronic PJI between sexes. A retrospective review was performed on all patients with an MSIS confirmed PJI who underwent a single or two-stage exchange at our institution from January 2010 to January 2021. Patient demographics, comorbidity characteristics, and outcomes were collected and compared between males and females. The primary outcome variable was disease-free survival at 1 year following definitive revision. Multivariable logistic regression analysis was performed to determine risk factors for failure. Of the 470 patients meeting final eligibility criteria, 250 were male and 226 were female (2 males and 4 females had a joint infection of either the contralateral side or a different joint and were treated as separate records). Of the patients in the cohort, 80% of the males (200/250) and 80% of the females (181/226) were found to be disease-free at 1-year follow-up (p > 0.99). Multivariable logistic regression analysis showed that nicotine use and diabetes, but not sex, were significant predictors of failure. Our study did not find a relationship between sex and outcome of revision for PJI. Further research is required to determine whether differences exist between males and females in the expression of PJI and outcomes following treatment.

Robotic-assisted technology does not influence functional outcomes among obese and morbidly obese total knee arthroplasty patients

PURPOSE

Despite benefits of total knee arthroplasty (TKA) on function and quality of life, obese patients have less improved functional outcomes following TKA compared to their normal weight counterparts. Furthermore, obesity is a risk factor for aseptic loosening and revision surgery following TKA. With known benefits of robotic-assisted TKA (RaTKA) in precision and patient satisfaction, we aimed to evaluate the differences in patient reported outcome and early complication rates for patients undergoing RaTKA versus conventional TKA among patients of varying BMI groups.

METHODS

This study was a retrospective cohort study of patients who underwent conventional versus RaTKA. Patients were grouped by BMI range (< 30 kg/m2, 30-40 kg/m2, and > 40 kg/m2). Patient-reported outcomes were measured by Oxford Knee Scores and 12-Item Short Form Survey scores preoperatively, 6-month, 1-year, and 2-year postoperatively. Mixed-effects linear models were built for each patient-reported outcome to assess the interaction between type of surgery and BMI while adjusting for known confounders such as demographic variables.

RESULTS

A total of 350 patients (n = 186 RaTKA, n = 164 conventional TKA) met inclusion criteria. SF-12 physical scores were significantly higher at 2-year follow-up among non-obese patients compared to obese and morbidly obese patients (p = 0.047). There was no statistically significant interaction between the type of surgery performed (RaTKA versus conventional TKA) and obesity regarding their effects on patient reported outcomes.

CONCLUSIONS

This study demonstrates no differences in functional outcomes among patients undergoing RaTKA compared to conventional TKA. Furthermore, obesity had no significant effect on this association.

LEVEL OF EVIDENCE

III.

Understanding Medical Optimization for Patients Undergoing Shoulder Arthroplasty

Many surgeons seek to optimize their patients' comorbid conditions preoperatively to reduce postoperative complications. To effectively optimize patients before total shoulder arthroplasty, the surgeon should be familiar with recognizing and treating common medical comorbidities found in an orthopedic patient including anemia, diabetes, malnutrition, cardiovascular conditions, and history of deep venous thrombosis. Screening for depression or other mental illness should also be conducted preoperatively and managed accordingly before surgery. Preoperative opioid use and smoking have significant effects on postoperative outcomes and should be addressed before surgery.

Minimum 2 Year Outcomes of All-Polyethylene Tibial Components in Patients who have Body Mass Index of 35 or Greater

BACKGROUND

Several studies have reported negative results after total knee arthroplasty (TKA) in obese patients. This study aims to analyze the minimum 2 year outcomes in patients who have a body mass index (BMI) ˃35 undergoing cemented TKA using an all-polyethylene tibial component (APTC) at a minimum of two years of follow-up.

METHODS

We retrospectively studied 163 obese patients (192 TKAs) who underwent a primary cemented TKA using an APTC comparing the outcomes of 96 TKA patients who had a BMI ˃35 to 39.9 (group A) with 96 patients who a TKA and a BMI ≥ 40 (group B). Median follow-up of groups A and B was 3.8 years and 3.5 years respectively (P=0.02). Multiple regression analyses were performed to evaluate independent risk factors associated with complications. Kaplan-Meier survival curves were estimated, defining failure as the need for any further femoral or tibial revision surgery with implant removal, irrespective of the reason.

RESULTS

There was no significant difference at the latest follow-up patient reported outcomes between both groups. Survivorship, as defined by revision for any reason, was 99% for group A and 99% for group B (P=1.00). There was one aseptic tibial failure in group A, and one septic failure in group B. Multiple regression analyses showed no significant associations between age (Odds Ratio [OR]= 1.00; P=0.98; 95% Confidence Interval (CI)= 0.93 to 1.08), sex (OR=1.38; P=0.70; 95% CI=0.26 to 7.25), BMI (OR=1.00; P=0.95; 95% CI=0.87 to 1.16), and complication rate.

CONCLUSIONS

At a median 3.7-year follow-up, the use of an APTC provided excellent outcomes and survivorship in patients who had Class 2 and Class 3 obesity.

The Safety and Efficacy of the Anterior Approach Total Hip Arthroplasty as per Body Mass Index

BACKGROUND

Obesity is associated with component malpositioning and increased revision risk after total hip arthroplasty (THA). With anterior approaches (AAs) becoming increasingly popular, the goal of this study was to assess whether clinical outcome post-AA-THA is affected by body mass index (BMI).

METHODS

This multicenter, multisurgeon, consecutive case series used a prospective database of 1,784 AA-THAs (1,597 patients) through bikini (n = 1,172) or standard (n = 612) incisions. Mean age was 63 years (range, 20-94 years) and there were 57.5% women, who had a mean follow-up of 2.7 years (range, 2.0-4.1 years). Patients were classified into the following BMI groups: normal (BMI < 25.0; n = 572); overweight (BMI: 25.0-29.9; n = 739); obese (BMI: 30.0-34.9; n = 330); and severely obese (BMI ≥ 35.0; n = 143). Outcomes evaluated included hip reconstruction (inclination/anteversion and leg-length, complications, and revision rates) and patient-reported outcomes including Oxford Hip Scores (OHS).

RESULTS

Mean postoperative leg-length difference was 2.0 mm (range: -17.5 to 39.0) with a mean cup inclination of 34.8° (range, 14.0-58.0°) and anteversion of 20.3° (range, 8.0-38.6°). Radiographic measurements were similar between BMI groups (P = .1-.7). Complication and revision rates were 2.5% and 1.7%, respectively. The most common complications were fracture (0.7%), periprosthetic joint infection (PJI) (0.5%), and dislocation (0.5%). There was no difference in dislocation (P = .885) or fracture rates (P = .588) between BMI groups. There was a higher rate of wound complications (1.8%; P = .053) and PJIs (2.1%; P = .029) among obese and severely obese patients. Wound complications were less common among obese patients with the 'bikini' incision (odds ratio 2.7). Preoperative OHS was worse among the severely obese (P < .001), which showed similar improvements (Change in OHS; P = .144).

CONCLUSION

AA-THA is a credible option for obese patients, with low dislocation or fracture risk and excellent ability to reconstruct the hip, leading to comparable functional improvements among BMI groups. Obese patients have a higher risk of PJIs. Bikini incision for AA-THA can help minimize the risk of wound complications.

Could Short Stems THA Be a Good Bone-Saving Option Even in Obese Patients?

Short femoral stems, with preservation of the femoral bone stock, are commonly used in recent years for hip replacement in younger and more active patients. Obesity is increasingly spreading even in the younger population. The aim of this case-series study is to evaluate short stems compared to traditional hip prostheses in the obese population. A total of 77 consecutive patients with a BMI greater than or equal to 30 Kg/m2 were enrolled in this prospective study and were divided into two groups: 49 patients have been implanted with short stems while 28 patients were implanted with traditional stems. All the patients were treated for primary osteoarthritis or avascular necrosis and all the stems were implanted by the same surgeon using a posterior approach. Clinical (Harris Hip Score—HHS, Western Ontario and McMaster Universities Osteoarthritis Index—WOMAC, visual analogue scale—VAS, 12-item Short Form Health Survey—SF-12) and radiographic outcomes were recorded. Radiological evaluations were carried out by three different blinded surgeons. A statistical analysis was performed (chi-square, t-test, Wilcoxon Rank Sum Test, 2-factor ANOVA). At a mean follow-up of 42.6 months both groups showed a marked improvement in pain and in the clinical scores between pre- and post-surgical procedures (p < 0.05) with no significant differences between the two groups at last follow-up (p > 0.05). The radiological evaluations, with high concordance correlation between the three blinded surgeons (ICC consistently >0.80), showed good positioning and osseointegration in all cases, with no significant differences in the restoration of the joint geometry and complications. No revisions were recorded during the follow-up period. In conclusion, short stems appear to be a good option for bone preservation even in obese patients, showing comparable results to traditional implants.

Effect of body mass index on symptomatic venous thromboembolism and prosthesis revision risk after total knee arthroplasty: a long-term study from China

OBJECTIVE

To investigate the effect of body mass index (BMI) on the risk of symptomatic VTE and prosthesis revision after total knee arthroplasty (TKA).

METHODS

Seven thousand one hundred eighty-two patients with primary unilateral TKA treated in our hospital from 2011 to 2020 were divided into four groups according to BMI: BMI < 25 kg/m², BMI 25 kg/m²-29.9 kg/m², BMI 30 kg/m²-34.9 kg/m² and BMI ≥ 35 kg/m². Incidence, Odds ratio and Kaplan-Meier survival analysis were used to evaluate the effects of BMI on symptomatic VTE and prosthesis revision risk after TKA.

RESULTS

The incidence of VTE after TKA was 8.9‰(64/7182). There was no significant difference in the incidence of VTE among different BMI groups(P = 0.452). Deep vein thrombosis mainly occurred in the distal lower extremities, especially in intermuscular veins. Revision rate of prosthesis after TKA was 6.4‰(46/7182). There was no significant difference in revision rate among different BMI groups(P = 0.718). In the univariate analysis of TKA, compared with patients with normal BMI, the risk of postoperative VTE and prosthesis revision in patients with overweight, obesity class I and obesity class II did not increase. Higher prosthesis revision rate and lower prosthesis survival rate were observed in BMI ≥ 35 kg/m² group, although the difference was not statistically significant.

CONCLUSIONS

Through such a retrospective large sample data of long-term follow-up, we believe that the higher BMI was not associated with the increased risk of symptomatic VTE and prosthesis revision after TKA. When TKA was used for appropriate indications, high BMI should not be considered as a contraindication.

Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty May Experience Higher Rates of Venous Thromboembolism When Prescribed Direct Oral Anticoagulants vs Aspirin

BACKGROUND

Morbidly obese (body mass index [BMI] >40 kg/m²) patients undergoing total joint arthroplasty (TJA) are at high risk for postoperative venous thromboembolism (VTE); however, there is debate surrounding the optimal pharmacologic agent for prevention of VTE after TJA in this patient subset. Current guidelines recommend against direct-acting oral anticoagulants (DOACs) in patients of BMI >40 kg/m² due to low quality evidence justifying their use. We evaluated whether patients of BMI >40 kg/m² undergoing primary unilateral TJA would have increased risk of postoperative VTE if prescribed DOACs compared to non-DOAC agents such as aspirin.

METHODS

This retrospective study analyzed 897 patients of BMI >40 kg/m² undergoing primary unilateral TJA. Demographic and comorbidity-related variables were collected. The association between postoperative VTE and prophylactic pharmacologic agent prescribed was evaluated by multivariate logistic regression.

RESULTS

After controlling for comorbidities, we found that the sole use of DOACs, specifically apixaban, for VTE prophylaxis was associated with an increased risk of developing VTE compared to prophylaxis with aspirin alone in patients of BMI >40 kg/m² (odds ratio 2.962, P = .016). Regardless of VTE prophylactic agent, patients with BMI >40 kg/m² undergoing TKA had at least 4.5-fold increased odds of developing VTE compared to patients undergoing THA (OR 4.830, P = .019).

CONCLUSION

In our retrospective study of a large sample size of patients with BMI >40 kg/m², we found that the use of DOACs, specifically apixaban, for VTE prophylaxis following TJA was associated with increased odds of a VTE complication compared to the use of aspirin alone.

What Are Drivers of Readmission for Readmission-Requiring Venous Thromboembolic Events After Primary Total Hip Arthroplasty? An Analysis of 544,443 Cases

BACKGROUND

Venous thromboembolism (VTE) is a potential postoperative complication after total hip arthroplasty (THA). These events present with a range of severity, and some require readmission. The present study aimed to identify unexplored risk factors for severe VTE that lead to hospital readmission.

METHODS

The Agency of Healthcare Research and Quality's National Readmissions Database was retrospectively queried for all patients who underwent primary THA (January 2016 to December 2018). Study population included patients who were readmitted for VTE within 90 days after an elective THA. Bivariate and multivariate regression analyses were performed using patient demographics, insurance status, elective nature of the surgery, healthcare institution characteristics, and baseline comorbidities.

RESULTS

Higher risk of readmission for VTE was evident among elderly (71-80 years vs <40 years: odds ratio [OR] 1.7, 95% confidence interval [CI] 1.3-2.2, P = .0002), male patients (OR 1.2, 95% CI 1.2-1.3). Nonelective THAs were associated with markedly higher odds of readmission for VTE (OR 20.5, 95% CI 18.9-22.2), peripheral vascular disease (OR 1.2, 95% CI 1.1-1.4), lymphoma (OR 1.5, 95% CI 1.1-2.1), metastatic cancer (OR 1.8, 95% CI 1.4-2.2), obesity (OR 1.5, 95% CI 1.4-1.6), and fluid-electrolyte imbalance (OR 1.1, 95% CI 1.0-1.2). Home health care (OR 0.8, 95% CI 0.7-0.8) and discharge to skilled nursing facility (OR 0.7, 95% CI 0.7-0.8) had lower odds of readmission for VTE vs unsupervised home discharge, while insurance type was not a significant driver(P > .05).

CONCLUSION

One in 135 THA patients is likely to experience a VTE requiring readmission after THA. Male patients, age >70 years, and specific baseline comorbidities increase such risk. Furthermore, discharge to a supervised setting mitigated the risk of VTE requiring readmission compared to unsupervised discharge. As VTE prophylaxis protocols continue to evolve, these patients may require optimized perioperative care pathways to mitigate VTE complications.

Effect of Body Mass Index on the outcomes of primary Total Knee Arthroplasty up to one year - A prospective study

Background

Obesity is a significant risk factor for developing knee osteoarthritis, and these cases suffer from complications following Total Knee Arthroplasty (TKA). An association between obesity and outcome after TKA is ambiguous. Knowledge is scarce about a definite relation between the two. This study aims to establish a correlation between obesity and early outcomes of TKA.

Methods

This prospective cross-sectional study was done in cases undergoing primary knee arthroplasty between September 2019 to August 2020. Obesity was classified in all cases, and multiple variables like pain, functional status, Range of Motion, knee deformity, and Patient Response Outcome Measures were recorded. Statistical analysis was performed using SPSS Statistical Software version 22.0 and R.3.2.0. The level of statistical significance was taken as p < 0.05.

Results

We studied 100 knees (37 bilateral and 26 unilateral) in 63 cases. Pain score decreased maximally in the normal and overweight group and minimal in class III obesity (p < 0.001). KSS, FKSS, and PROMs gradually improved in all, except in morbidly obese (p < 0.001). Although the improvement in all variables was minimum in class III obesity compared to other classes of obesity, the margin of difference from the preoperative period was maximum in class III obese participants.

Conclusion

All cases, irrespective of class of obesity, experienced a comparable improvement in their knee function and improved quality of life. In addition, the TKA offered substantial benefits in terms of pain relief, knee stability, walking distance, range of movement of the knee, and stair climbing.

Does Surgical Approach for Total Hip Arthroplasty Impact Infection Risk in the Obese Patient? A Systematic Review

This systematic review evaluated the combined effects of obesity and surgical approach on periprosthetic joint infection (PJI) rates after total hip arthroplasty (THA). Wound complication and PJI rates were elevated among patients with body mass index (BMI) of 30 kg/m2 or greater and 35 kg/m2 or greater, respectively, with the direct anterior approach (DAA). A BMI of 30 kg/m2 or greater also increased the risk of PJI with the posterior approach. Patients with BMI of 30 kg/m2 or greater undergoing anterolateral approach THA did not have increased risk of PJI. Patients with elevated BMI (≥30 kg/m2) are at risk for PJI, regardless of approach. Patients undergoing DAA THA who have BMI of 35 kg/m2 or greater may have an increased risk of PJI compared with those undergoing THA with other approaches. [Orthopedics. 2022;45(2):e67-e72.].

Are Morbidly Obese Patients Equally Benefitting From Care Improvements in Total Hip Arthroplasty?

BACKGROUND

Morbidly obese patients have increased rates of complications following primary total hip arthroplasty (THA) and it is not clear whether improvements in THA care pathways are equally benefitting these patients. The purpose of this study is to assess if reductions in complications have similarly improved for both morbidly obese and non-morbidly obese patients after THA.

METHODS

Patients undergoing primary THA between 2011 and 2019 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by body mass index (BMI) <40 and ≥40 kg/m². Thirty-day rates of infectious complications, readmissions, reoperation, and any complication were assessed. Trends in complications were compared utilizing odds ratios and multivariate analyses.

RESULTS

In total, 234,334 patients underwent THA and 16,979 (7.8%) had BMI ≥40 kg/m². Patients with BMI ≥40 kg/m² were at significantly higher odds for readmission, reoperation, and infectious complications. Odds for any complication were lower for morbidly obese patients in 2011, not different from 2012 to 2014, and higher from 2015 to 2019 compared to lower BMI patients. Odds for any non-transfusion complication were higher for morbidly obese patients and there was no improvement for either group over the study period. There were improvements in rates of readmission and reoperation for patients with BMI <40 kg/m² and readmission for BMI >40 kg/m².

CONCLUSION

Odds for readmission and reoperation for non-morbidly obese patients and readmission for morbidly obese patients improved from 2011 to 2019. Reductions in transfusions are largely responsible for improvements in overall complication rates. Although morbidly obese patients remain at higher risk for complications, there does not appear to be a growing disparity in outcomes between morbidly obese and non-morbidly obese patients.

Obesity, Comorbidities, and the Associated Risk among Patients Who Underwent Total Knee Arthroplasty in Alberta

Obesity, a common risk factor for osteoarthritis (OA), accelerates joint deterioration resulting in the need for early total knee arthroplasty (TKA). The role of obesity in the management of OA remains a controversial topic. In this study, we examined whether obesity along with other comorbidities is associated with peri/postoperative complications in patients who underwent primary unilateral TKA in Alberta, Canada. A retrospective secondary analysis was performed on data extracted from data repository of patients (n = 15,151) who underwent TKA between 2012 and 2016. The sample was divided into five groups based on body mass index (BMI) classification developed by the World Health Organization. The associations between dependent variable (presence or absence of a complication or comorbidity) with the independent variables (year of surgery, age, sex, length of surgery, and BMI groups) were examined using binomial logistic regression. Results showed that obese classes I, II, and III, irrespective of other covariates, were more likely to have diabetes and pulmonary embolism (p < 0.001) compared with the normal BMI group. Patients with obese class III compared with the patients in normal BMI group were more likely to have deep wound infection (p = 0.04). Patients with comorbidities were more likely to have a blood transfusion, infection, pulmonary embolism, and readmission. Patients in higher BMI groups or with comorbidities were more likely to experience peri/postoperative complications following TKA, though the level of risk depends on the severity of obesity. These findings may be used by health care providers to educate patients in higher BMI groups about the risks of TKA and optimize comorbidities prior to the surgery.

Body Composition Changes in the Immediate Peri-operative Period Following Total Joint Arthroplasty

BACKGROUND

Bioimpedance analysis (BIA) is a readily available tool to assess body composition in a clinical setting. BIA has received little attention in orthopaedics and namely joint arthroplasty. This study aims to quantify changes in body composition in the immediate peri-operative period following total joint arthroplasty.

METHODS

Adults scheduled for elective total joint arthroplasty were recruited to participate. Patients underwent BIA scans in the immediate peri-operative period: pre-operative on their day of surgery, post-operative day 0, and post-operative day 1.

RESULTS

67 patients were enrolled to undergo BIA scans. Mean age was 62.64 ± 10.28 years old, and 49.2% were females. The all-supine cohort exhibited a 0.36 ± 0.61 kg increase in dry lean mass (p < 0.001) and 1.30 ± 2.14 kg increase in lean body mass on postoperative day 0 (p < 0.001). Patients received to 1.16 ± 0.58 kg of fluid mass, on average.

CONCLUSION

BIA is a rapid, portable tool that allows for body composition analysis of an inpatient surgical population. This study demonstrated that BIA can detect net fluid changes and may approximate implant mass following total joint arthroplasty. This may aid surgeons in interpreting post-operative body composition changes.

Weight-Based Aspirin Dosing May Further Reduce the Incidence of Venous Thromboembolism Following Primary Total Joint Arthroplasty

BACKGROUND

Obesity poses a challenge to thromboembolic prophylaxis following total joint arthroplasty (TJA). The purpose of this study is to evaluate a weight-based aspirin dosing regimen for prevention of venous thromboembolism (VTE) following TJA.

METHODS

This is a retrospective observational study of 2403 patients who underwent primary total hip or knee arthroplasty at one institution. A weight-based aspirin dosing regimen for VTE prophylaxis was administered to 1247 patients: patients weighing ≥120 kg received 325 mg aspirin twice daily (BID) and those weighing <120 kg received 81 mg aspirin BID for 4 weeks. In total, 1156 patients in the comparison cohort received 81 mg aspirin BID. VTE and gastrointestinal bleeding events were identified through chart review at 42 days and 6 months postoperatively. A multivariable logistic regression was performed to adjust for covariates.

RESULTS

The weight-based aspirin cohort had a significantly lesser incidence of VTE at 42 days (P = .03, relative risk [RR] 0.31, 95% confidence interval 0.12-0.82) and 6 months (P = .03, RR 0.38, 95% confidence interval 0.18-0.80). There was no difference in VTE incidence between total hip arthroplasty and total knee arthroplasty cases (P = .8). There was no difference in gastrointestinal bleeding events between the cohorts at 42 days (P = .69) or 6 months (P = .92). Subanalysis of patients weighing ≥120 kg demonstrated a significant difference between the cohorts with a VTE incidence of 3.48% and 0% in the 81 mg and weight-based cohorts, respectively (P = .02).

CONCLUSION

Patients prescribed a weight-based aspirin regimen had significantly fewer VTEs after TJA compared to historical controls with an RR reduction of 69% at 6 weeks and 62% at 6 months postoperatively. This suggests the need to factor patient weight when determining postoperative VTE prophylaxis with aspirin.

The Association of Body Mass Index with Surgical Time Is Mediated by Comorbidity in Patients Undergoing Total Hip Arthroplasty

Overweight represents a major issue in contemporary orthopaedic practice. A higher body mass index (BMI) is associated with an increase of perioperative complications following several orthopaedic procedures, in particular total hip arthroplasty (THA). However, the influence of overweight on THA surgical time is controversial. In this study, we investigated the association between BMI and surgical time analyzing the role of patients’ comorbidities. We conducted a retrospective study on 748 patients undergoing THA at our institutions between 2017 and 2018. Information regarding medical diseases was investigated and the burden of comorbidity was quantified using the Charlson score (CCI). Surgical time and blood loss were also recorded. Median surgical time was 76.5 min. Patients with surgical time above the median had both a higher BMI (28.3 vs. 27.1 kg/m²; p = 0.002); and CCI (1 vs. 0; p = 0.016). According to linear regression, surgical time was associated with BMI in the unadjusted model (p < 0.0001), after adjusting for age and sex (p < 0.0001), and in the multivariable model (p = 0.005). Furthermore, BMI was associated with increased surgical time only in patients with a Charlson score above the median, but not in others. Obesity is associated with increased surgical time during THA, especially in pluricomorbid patients, with a higher risk of perioperative complications.

Morbid obesity is not a contraindication to lower limb arthroplasty

There are concerns that increased BMI is associated with a greater length of stay (LOS) and perioperative complications following total knee (TKR) and total hip replacements (THR). We analysed data from a six-month period to see if there was a correlation between BMI and LOS. We performed a subgroup analysis for patients with morbid obesity (BMI >40) looking at perioperative complications. 285 TKRs and 195 THRs were analysed. For TKRs, the average length of stay was 2.7 days. The average BMI was 32.4. There was no significant correlation between BMI and LOS (r=-0.0447, p=0.2267). The morbidly obese category (n=33) had the shortest LOS (2.5 days) compared to other BMI categories. 30- day readmission rate was 6%. 90-day re-admission rate was 12%. Six patients had minor wound issues requiring no intervention or antibiotics only. The was one prosthetic joint infection, one stitch abscess, one DVT and one patellar tendon injury. For THRs, the average LOS was 2.9 days. The average BMI was 29.9. There was no significant correlation between BMI and LOS (r=0.007, p=0.4613). The morbid obese category (n=9) had the shortest LOS (1.9 days) compared to other BMI categories. No patients were readmitted within 90 days or had documented complications. We have shown that for TKRs and THRs, increased BMI is not associated with increased LOS. The morbidly obese were found to have the shortest LOS. Re-admission rates and complications were commendable for patients with morbid obesity. BMI >40 is not a contraindication to TKR or THR.

Spine Surgery HCAHPS Patient Satisfaction Survey Results Inversely Correlate with Survey Response Time

STUDY DESIGN

Retrospective review.

OBJECTIVE

The aim of this study was to understand the potential correlation of the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey response time on reported satisfaction following spine surgery hospitalization.

SUMMARY OF BACKGROUND DATA

With increasing emphasis on patient satisfaction metrics, such as HCAHPS, hospital reputations, and reimbursements are being affected by the results of such surveys. HCAHPS is a 32-question survey about patient experience in the hospital and after discharge.

METHODS

HCAHPS surveys were routinely sent to all patients admitted after spine surgery at an academic medical center between January 2013 and August 2017. Survey data, survey return time, patient demographics, and 30-day postoperative outcomes were gathered for all spine surgery patients who returned the survey. Multivariate regression analysis controlling for age, sex, BMI, functional status, American Society of Anesthesiologists class, education, and race was used to determine whether there were differences in rates of "Top Box" response between different time ranges of survey return.

RESULTS

In total, 1495 consecutive spinal surgery patients who returned their HCAHPS survey were identified. Of these, 31.51% returned their surveys within 21 days, 48.09% returned them between 22 to 42 days, 13.58% returned them between 43 to 64 days, and 6.82% returned them ≥65 days after distribution. Multivariate regression demonstrated no statistical differences in reported satisfaction between surveys returned between days 0 to 21 and days 22 to 42. However, there were significantly lower scores reported by surveys returned on days 43 to 64 and 65 plus days.

CONCLUSION

Centers for Medicare and Medicaid Services only considers HCAHPS surveys returned within the first 42 days. It appears that the survey responses are similar over this time period. Beyond this time, lower scores are reported. Further attention to this less satisfied, later HCAHPS survey returning group seems warranted.Level of Evidence: 2.

Failure to Medically Optimize Before Total Hip Arthroplasty: Which Modifiable Risk Factor Is the Most Dangerous?

Background

There is mounting evidence that smoking, abnormal body mass index (BMI), uncontrolled diabetes, and poor nutritional status are associated with complications after total hip arthroplasty (THA). The goal of the present study was to evaluate the consequences of failure to medically optimize Medicare-eligible patients with respect to these key modifiable health targets by assessing complications in the early postoperative period after THA.

Methods

The National Surgical Quality Improvement Program database was queried for all primary THAs performed in 2018. Data were collected on preoperative serum albumin, BMI, diabetes, and tobacco use as well as postoperative infections, readmissions, complications, and mortality. We identified 47,924 THA patients with a median BMI of 29 kg/m² and age of 72 years, and 60% of whom were female.

Results

We found that preoperative albumin <3.5 g/dL, BMI ≥40 kg/m², tobacco use, and diabetes were all individually associated with increased risk of postoperative complications. Serum albumin <3.5 g/dL was the greatest overall risk factor for infection (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 2.3-4.4, P < .0001), readmission (OR: 2.2, 95% CI: 1.9-2.5, P < .0001), any complication (OR: 4.2, 95% CI: 3.8-4.6, P < .0001), and mortality (OR: 7.5, 95% CI: 5.3-10.6, P < .0001).

Conclusions

Low albumin, elevated BMI, tobacco use, and diabetes are associated with increased risk of postoperative infection, readmission, any complication, and mortality after primary THA. Low albumin poses the greatest risk of these. Preoperative optimization should be obtained in all patients before elective surgery, and the final decision for surgery should be individually made between a surgeon and patient.

Level of Evidence

IV.

Obesity in short stem total hip arthroplasty using a minimally invasive supine anterolateral approach-a risk factor for short-term complications?

Purpose

Obesity is associated with increased risk for surgical complications in total hip arthroplasty (THA). The impact of obesity on short-term complication in minimally invasive (MIS) anterolateral approach is not well known. Therefore, this study was conducted to evaluate the early complications within the first 90 days after THA using a MIS anterolateral approach with a short-curved stem stratified by Body Mass Index (BMI).

Patients and methods

A single centre consecutive series of 1052 hips in 982 patients (index surgery 2014–2019) with a short-curved stem and press fit cup implanted using a MIS anterolateral approach in supine position were screened for inclusion. Inclusion criteria were defined as end-stage primary osteoarthritis of the hip. Eventually, 878 implantations in 808 patients were included and stratified by body mass index (BMI). Peri-operative complications, within the first 90 days after surgery, were retrospectively evaluated.

Results

Severely obese patients (BMI ≥ 35 kg/m²) and morbidly obese patients (BMI ≥ 40 kg/m²) demonstrated a significantly increased operation time (p < 0.001) and a higher risk for general surgical complications (p = 0.015) (odds ratio (OR) = 4.365; OR = 4.985), periprosthetic joint infection (PJI) (p = 0.001) (OR = 21.687; OR = 57.653), and revision (OR = 8.793; OR = 20.708).

Conclusion

The risk for early PJI and overall surgical complications in MIS anterolateral approach is significantly increased in severely and morbidly obese patients. This leads to a significantly higher risk for revision surgery after index surgery within the first 90 days. A BMI above 35 kg/m² is the clear threshold for increased risk of PJI in MIS anterolateral THA with a short curved stem. As the surgical complications are comparable to other approaches, MIS anterolateral short stem THA is also feasible with increasing BMI.

Pediatric obesity and perioperative medicine

PURPOSE OF REVIEW

Childhood obesity is a public health emergency that has reached a pandemic level and imposed a massive economic burden on healthcare systems. Our objective was to provide an update on (1) challenges of obesity definition and classification in the perioperative setting, (2) challenges of perioperative patient positioning and vascular access, (3) perioperative implications of childhood obesity, (3) anesthetic medication dosing and opioid-sparing techniques in obese children, and (4) research gaps in perioperative childhood obesity research including a call to action.

RECENT FINDINGS

Despite the near axiomatic observation that obesity is a pervasive clinical problem with considerable impact on perioperative health, there have only been a handful of research into the many ramifications of childhood obesity in the perioperative setting. A nuanced understanding of the surgical and anesthetic risks associated with obesity is essential to inform patients' perioperative consultation and their parents' counseling, improve preoperative risk mitigation, and improve patients' rescue process when complications occur.

SUMMARY

Anesthesiologists and surgeons will continue to be confronted with an unprecedented number of obese or overweight children with a high risk of perioperative complications.

The Pharmacology, Efficacy, and Safety of Rivaroxaban in Obese Patient Populations

Cardiovascular disease (CVD) remains the leading cause of death in the USA. Several risk factors have been identified, and obesity has become one of prominent concern. Excessive weight is considered a risk factor for CVD based on evidence linking it to a hypercoagulable state. Considering the prevalence of CVD and obesity in the USA, along with the increased risk for thrombus-related events, anticoagulation plays a significant role in prevention and treatment. Direct oral anticoagulants have taken the place of many traditional anticoagulants. Considering the recently approved indications and continued postmarketing studies conducted with rivaroxaban, this updated review provides data on the overall impact of obesity on this compound. This includes data obtained from both healthy obese volunteers and obese patients with various CVD conditions enrolled in rivaroxaban clinical trials, along with data obtained from postmarketing real-world evidence studies. Assessment of the clinical pharmacology and population pharmacokinetics in obese individuals revealed no clinically relevant effects of increased weight. Additionally, subgroup analyses from each of the pivotal phase III trials supporting the current approved labeling also demonstrated consistent efficacy and safety results in obese patients. Lastly, these findings are further supported by several recent real-world evidence studies assessing the continued effectiveness and safety of rivaroxaban. In conclusion, rivaroxaban's overall pharmacological and clinical profile remained consistent in obese adults when assessed in both drug development and postmarketing studies, supporting the premise that higher weight does not necessitate adjustment in either dose strength or regimen.

Risk factors for ecchymosis in patients receiving rivaroxaban for thromboprophylaxis after total knee arthroplasty: a retrospective cohort study

WHAT IS KNOWN AND OBJECTIVE

Ecchymosis of the limb is commonly seen after total knee arthroplasty (TKA) when using anticoagulants for thromboprophylaxis, but it is unknown which factors may predispose patients to an increased risk. The aim of this study was to evaluate risk factors for ecchymosis in patients receiving rivaroxaban after TKA.

METHODS

A retrospective, single-centre cohort analysis was conducted. The electronic medical records of patients admitted to the Department of Orthopedics during January 2018 to December 2019 and who received rivaroxaban 10 mg daily after TKA were reviewed for documentation of ecchymosis. Baseline demographics, laboratory values and surgical information were included for analysing their relationship with ecchymosis.

RESULTS AND DISCUSSION

A total of 227 patients were included in the study. Among them, 54 patients (23.8%) developed ecchymosis, and 173 did not. The ecchymosis group had a higher proportion of patients with a body weight >60 kg [83.33% vs. 50.00%, p = 0.0004] and hypertension [61.11% vs 41.46%, p = 0.0304]. The ecchymosis group also had a higher BMI [26.04 ± 2.71 kg/m² vs 24.52 ± 3.18 kg/m² , p = 0.0066] mean arterial pressure (MAP) recorded from post-operation day 1 to day 3 [105.21 mmHg vs 91.52 mmHg, p = 0.0003]. However, serum albumin concentrations before surgery [3.85 g/dL vs. 4.20 g/dL, p = 0.0225] and on post-operation day 3 [3.50 g/dL vs. 3.91 g/dL, p = 0.0370] were lower in the ecchymosis group. Serum haemoglobin on post-operation day 3 was also lower [10.07 g/dL vs. 11.57 g/dL, p = 0.0459]. Five risk factors for ecchymosis were identified by binary logistic regression: mean MAP (from POD1 to POD3) (OR=2.901, 95% CI: 2.522-3.293, p < 0.001), BMI (OR=2.513, 95% CI: 1.929-3.011, p < 0.001), history of hypertension (OR=2.661, 95% CI: 1.272-4.535, p = 0.032), post-surgery serum albumin level (OR=0.848, 95% CI: 0.735-0.977, p = 0.023) and post-surgery serum haemoglobin level (OR=0.943; 95% CI: 0.898-0.990, p = 0.018).

WHAT IS NEW AND CONCLUSION

The present analyses identified that BMI, history of hypertension, mean MAP (POD1 to POD3), post-surgery serum albumin level and post-surgery serum haemoglobin level were independent risk factors for rivaroxaban-related ecchymosis in patients who underwent TKA. These factors should be considered and optimized before starting rivaroxaban therapy.

Complication rates and resource utilization after total hip and knee arthroplasty stratified by body mass index

Over 295,000 patients from 2016 to 2018 in a national database were grouped into normal weight (BMI 18.5 to <25 kg/m²), overweight (25 to <30), type-1 obese (30 to <35), type-2 obese (35 to <40), and type-3 obese (40 or higher). Differences in resource utilization and complication rates across BMI categories were compared. In comparison to normal weight patients, overweight and obese patients undergoing TJA were at risk for increased resource utilization and various early complications. Patients undergoing TKA with a BMI up to 45 kg/m² are at similar risk for 30-day postoperative complications when compared to type-1 obese patients.

Early Outcomes After Surgical Management of Geriatric Patella Fractures

Objectives:

To report the incidence and risk factors for prolonged hospitalization, discharge to a facility, and postoperative complications in geriatric patients who underwent surgery for patella fracture.

Design:

Retrospective database review.

Setting:

The American College of Surgeons—National Surgical Quality Improvement Program (NSQIP) collects data from 600 hospitals across the United States.

Patients/Participants:

NSQIP patients over 65 years of age with patella fractures.

Intervention:

Surgical fixation of patella fracture including extensor mechanism repair.

Main Outcome Measurements:

Prolonged hospitalization, discharge to a facility, and 30-day post-operative complications.

Results:

1721 patients were included in the study. The average age was 74.9 years. 358 (20.8%) patients were male. 122 (7.1%) patients had a length of stay greater than 7 days. Factors associated with prolonged length of stay include pre-existing renal failure, need for emergent surgery, and time to surgery greater than 24 hours from admission. 640 patients (37.2%) of patients were discharged to a facility after surgery. Discharge to facility was associated with age >77 years, obesity, anemia, thrombocytopenia, pre-operative SIRS, and CCI > 0.5. Admission from home decreased the odds of discharge to a facility. The most common postoperative complications in this population were unplanned readmission (3.4%), unplanned reoperation (2.7%), surgical site infection (1.1%), mortality (1.0%), venous thromboembolism (0.8%), and wound dehiscence (0.2%). Complication rates increased with anemia and ASA class IV-V.

Conclusions:

Geriatric patients undergoing operative intervention for patella fractures are at high risk for prolonged hospitalization, discharge to facility, unplanned readmission or reoperation, and surgical site complications in the first 30 days following surgery. This study highlights modifiable and non-modifiable risk factors associated with adverse events. Early recognition of these factors can allow for close monitoring and multidisciplinary intervention in the perioperative period to improve outcomes.

Level of Evidence:

Prognostic level III.

Diabetes Status Affects Odds of Body Mass Index-dependent Adverse Outcomes After Total Hip Arthroplasty

INTRODUCTION

Obesity and diabetes have independently been shown to predispose to adverse outcomes after total hip arthroplasty (THA). These may have a coupled effect on perioperative risks. The purpose of this study was to evaluate the effect of body mass index (BMI) on adverse outcomes in nondiabetic (ND), non-insulin-dependent diabetes mellitus (NIDDM), and insulin-dependent diabetes mellitus (IDDM) patients.

METHODS

Patients undergoing primary THA were selected from the National Surgical Quality Improvement Program Database from 2012 to 2016 and categorized as ND, NIDDM, and IDDM. BMI, demographics, and 30-day perioperative outcomes were assessed for each group. Multivariate logistic regressions controlling for demographics, functional status, and American Society of Anesthesiologists were used to determine the odds ratio of serious adverse event (SAE) in each diabetes group for patients with BMI ≥ 40 kg/m compared with a control group of ND patients with a normal BMI (18.5 to 24.9 kg/m).

RESULTS

A total of 108,177 patients were included. The results demonstrate that ND (odds ratio 1.65; P < 0.001) and NIDDM (odds ratio 1.75; P = 0.007) patients have similar risks of SAE, whereas IDDM (odds ratio 2.79; P < 0.001) patients have a greater risk of adverse events, particularly at BMIs greater than 40 kg/m.

DISCUSSION

Consistent with previous reports, ND (odds ratio 1.65; P < 0.001) and NIDDM (odds ratio 1.75; P = 0.007) morbidly obese patients (BMI > 40 kg/m) had an increased odds of SAEs after THA, but for IDDM (odds ratio 2.79; P < 0.001) patients this increased odds was notably higher. Although patients with IDDM have increased rates of adverse events compared with ND and NIDDM patients, these findings should not be used to establish strict BMI cutoffs in patients with IDDM. Nonetheless, the results suggest additional factors, such as patient medical history and diabetes control, should be considered when evaluating patients with IDDM for THA.

LEVEL OF SIGNIFICANCE

Level III.

How I treat obese patients with oral anticoagulants

Obesity has become a major threat to health worldwide. The prevalence of obesity is rapidly increasing, so much so that the World Health Organization has declared obesity as a global epidemic. Obesity is associated with multiple health problems, including venous thromboembolism and atrial fibrillation, both of which are treated with anticoagulation. However, obesity and treatments for obesity such as bariatric surgery can influence absorption, excretion, pharmacokinetics, and pharmacodynamics of various anticoagulants. This results in uncertainty regarding the best antithrombotic strategies in this population, particularly in the morbidly obese. In the recent years, several studies have attempted to investigate anticoagulation use in this population and provided more insight. Herein, we present 4 cases of anticoagulant use in the obese to illustrate the common challenges faced by clinicians and discuss our approach. Whenever possible, we provide a review of the literature and base our recommendations on the best available evidence.

Potential Risk Factors Contributing to Development of Venous Thromboembolism for Total Knee Replacements Patients Prophylaxed With Rivaroxaban: A Retrospective Case-Control Study

Rivaroxaban after total knee arthroplasty (TKA) is used to prevent postoperative venous thromboembolism (VTE); however, despite thromboprophylaxis, some patients still develop postoperative VTE. To determine whether tourniquet time, time to initiate rivaroxaban (TTI_RIV), or Body Mass Index (BMI) was associated with postoperative VTE. A retrospective case-control study was conducted. Those patients that developed VTE despite prophylaxis (cases) were compared to controls (no VTE). A univariate analysis was conducted (p < 0.05 statistically significant). Seven VTE cases were identified from 234 TKA-patients. Patients with and without VTE had BMI of 40.1 ± 9.1 and 32.8 ± 7.5, respectively (p = 0.064). TTI_RIV in VTE and control group was 28.2 ± 4.7 hours and 26.4 ± 4.2 hours, respectively (p = 0.39). Mean tourniquet time in VTE and control group was 65.0 ± 8.7 minutes and 49 ± 8.8 minutes, respectively (p = 0.0007). Statistically significant differences in tourniquet times were noted between VTE and non-VTE group but not for TTI_RIV and BMI. Prolonged tourniquet use could pose a potential risk factor for postoperative VTE. Thromboprophylaxis management may need to be adjusted, based on patient-specific factors that could include increasing doses of oral anticoagulants and/or mechanical prophylaxis. However, further large-scale studies are required to establish pathophysiology.

Perioperative Complications Stratified by Body Mass Index for the Direct Anterior Approach to Total Hip Arthroplasty

BACKGROUND

Previous studies have addressed the increased risk of perioperative complications in the obese and morbidly obese populations undergoing total hip arthroplasty. Over the last 15 years, the direct anterior approach has increased in popularity. The purpose of this study is to compare the 90-day perioperative complication rate of total hip arthroplasty performed through the direct anterior approach stratified by body mass index (BMI).

METHODS

Perioperative complications both intraoperative and up to 90 days postoperative were identified in a case series of 1808 primary total hip arthroplasties performed through a direct anterior approach. The patients were stratified according to BMI. Demographics of age, side, sex, and American Society of Anesthesiologists score were recorded. Medical and surgical complications including National Surgical Quality Improvement Program complications, length of stay, reoperation rate, readmission rate, and length of operation were recorded. Bivariate analysis and analysis of variance were performed.

RESULTS

Morbidly obese patients (BMI > 40) demonstrated increased American Society of Anesthesiologists scores, increased surgical times with statistically significant increase in number of patients with surgical complications, National Surgical Quality Improvement Program complications, deep infection, and wound breakdown. Grading the severity of complications also demonstrated the morbidly obese had a higher risk of experiencing more severe complications. Underweight patients (BMI < 18.5) demonstrated a statistically significant readmission rate.

CONCLUSION

In stratifying patients undergoing the direct anterior approach for total hip arthroplasty by BMI, a greater rate of surgical complications both in number and in severity occurs with the morbidly obese undergoing total hip arthroplasty through a direct anterior approach.

The Obesity Paradox: Body Mass Index Complication Rates Vary by Gender and Age Among Primary Total Hip Arthroplasty Patients

BACKGROUND

High body mass index (BMI) has long been recognized as a risk factor for postoperative complication among total hip arthroplasty (THA) patients. However, recent studies showed mixed results in the effect of high BMI on surgical outcomes. Our study is to examine the association of preoperative BMI with complication incidence, stratified by age and gender.

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Project database to identify patients who underwent elective primary THA between 2012 and 2016. We examined the associations between BMI as a continuous and a categorical variable and risk of 30-day postoperative complication, using 2 multiple polynomial logistic regression models. We also created predictive plots to graphically assess the relationship between BMI and complication by gender and age.

RESULTS

In total, 117,567 eligible patients were included in the analyses. The predictive probability of all-type postoperative complications showed a U-shaped relationship with continuous BMI values (range 10-65 kg/m²). The lowest complication risks occurred in patients with BMI between 35 and 40. Females had higher complication rate than males across all BMI values. This U-shaped relationship was only observed among patients younger than 60 years old, while the associations appear to be inversely linear among patients aged greater than 60 years.

CONCLUSION

Our results suggest that the current theory of a linear association between BMI and complication risk may not apply to elective primary THA. Strict BMI cutoffs may not minimize risk, especially among patients over 60 years old. Orthopedic surgeons should factor in patient-specific variables of age and gender when determining acceptable surgical risk given a particular BMI value.

Results of Cemented Posterior-Stabilized Total Knee Arthroplasty in Obese Patients With an Average 10-Year Follow-Up

BACKGROUND

Obese and morbidly obese patients undergoing primary total knee arthroplasty (TKA) place significant stress at the bone-cement-implant interface over the life of the patient. The purpose of this study is to evaluate results of cemented, posterior-stabilized TKA in obese and morbidly obese patients at an average follow-up of 10 years.

METHODS

Retrospective study of 181 patients who had a cemented, posterior-stabilized TKA between 2000 and 2013 with body mass index >35 at the time of surgery was conducted. Clinical data and radiographs were evaluated along with survivorship, complications, and revisions. Minimum follow-up was 5 years with an average follow-up of 10 years.

RESULTS

There were 135 women and 46 men in the study, with mean age of 60.2 years (range 43-80), mean body mass index of 42.0 (range 35.1-66.1), and an average follow-up of 10 years (range 5-18). There were a total of 39 failures (22%) that underwent revision TKA surgery with mean time to revision of 8 years. Failures included 25 (14%) cases of aseptic loosening; 9 (5%) polyethylene wear; 2 (1%) prosthetic joint infection; and 3 additional revisions for instability, pain, and stiffness. There were a total of 11 cases of isolated tibial component loosening and 13 for both tibial and femoral loosening. Survivorship at 15 years with aseptic loosening as the endpoint was 86.7%, and for all causes 79.6% at 15 years.

CONCLUSION

Aseptic loosening is the leading cause of failure following TKA in obese and morbidly obese patients with decreasing survivorship from 96.1% to 91.2% and 86.7% at 5, 10, and 15 years, respectively.