Morbid Obesity in Total Knee Arthroplasty: Joint-Specific Variance in Outcomes for Operative Time, Length of Stay, and Readmission

Is Operative Time Associated With Obesity-related Outcomes in TKA?

BACKGROUND

Obesity-based cutoffs in TKA are premised on higher rates of postoperative complications. However, operative time may be associated with postoperative complications, leading to an unnecessary restriction of TKA in patients with obesity. If operative time is associated with these obesity-related outcomes, it should be accounted for in order to ensure all measurable factors associated with negative outcomes are examined for patients with obesity after TKA.

QUESTIONS/PURPOSES

We asked: (1) Is operative time, controlling for BMI class, associated with readmission, reoperation, and postoperative major and minor complications? (2) Is operative time associated with a difference in the direction or strength of obesity-related adverse outcomes?

METHODS

In this comparative study, we extracted all records on elective, unilateral TKA between January 2014 and December 2020 in the American College of Surgeons National Surgical Quality Improvement Program database, resulting in an initial sample of 394,381 TKAs. Patients with emergency procedures (0.1% [270]) and simultaneous bilateral TKAs (2% [8736]), missing or null data (1% [4834]), and those with operative times less than 25 minutes (0.1% [548]) were excluded, leaving 96% (379,993) of our original sample size. The National Surgical Quality Improvement Program database was selected because of its inclusion of operative time, which is not found in any other national database. BMI was subdivided into underweight (BMI < 18.5 kg/m 2 , < 1% [719]), normal weight (BMI 18.5 to 24.9 kg/m 2 , 9% [34,513]), overweight (BMI 25.0 to 29.9 kg/m 2 , 27% [101,538]), Class I obesity (BMI 30.0 to 34.9 kg/m 2 , 29% [111,712]), Class II obesity (BMI 35.0 to 39.9 kg/m 2 , 20% [76,605]), and Class III obesity (BMI ≥ 40.0 kg/m 2 , 14% [54,906]). The mean operative time was 91 ± 36 minutes, 61% of patients were women (233,062 of 379,993), and the mean age was 67 ± 9 years. Patients with obesity tended to be younger and more likely to have preoperative comorbidities and longer operative times than patients with normal weight. Multivariable logistic regression models examined the main effects of operative time with respect to 30-day readmission, reoperation, and major and minor medical complications, while adjusting for BMI class and other covariates including age, sex, race, smoking status, and number of preoperative comorbidities. We then evaluated the potential interaction effect of BMI class and operative time. This interaction term helps determine whether the association of BMI with postoperative outcomes changes based on the duration of the surgery, and vice versa. If the interaction term is statistically significant, it implies the association of BMI with adverse postoperative outcomes is inconsistent across all patients. Instead, it varies with the operative time. Adjusted odds ratios and 95% confidence intervals were calculated, and interaction effects were plotted.

RESULTS

After controlling for obesity, longer procedure duration was independently associated with higher odds of all outcomes (30-minute estimates; adjusted ORs are per minute), including readmission (9% per half-hour of surgical duration; adjusted OR 1.003 [95% CI 1.003 to 1.004]; p < 0.001), reoperation (15% per half-hour of surgical duration; adjusted OR 1.005 [95% CI 1.004 to 1.005]; p < 0.001), postoperative major complications (9% per half-hour of surgical duration; adjusted OR 1.003 [95% CI 1.003 to 1.004]; p < 0.001), and postoperative minor complications (18% per half-hour of surgical duration; adjusted OR 1.006 [95% CI 1.006 to 1.007]; p < 0.001). The interaction effect indicates that patients with obesity had lower odds of reoperation than patients with normal weight when operative times were shorter, but higher odds of reoperation with a longer operative duration.

CONCLUSION

We found that operative time, a proxy for surgical complexity, had a moderate, differential association with obesity over a 30-minute period. Perioperative modification of surgical complexity such as surgical techniques, training, and team dynamics may make safe TKA possible for certain patients who might have otherwise been denied surgery. Decisions to refuse TKA to patients with obesity should be based on a holistic assessment of a patient's operative complexity, rather than strictly assessing a patient's weight or their ability to lose weight. Future studies should assess patient-specific characteristics that are associated with operative time, which can further push the development of techniques and strategies that reduce surgical complexity and improve TKA outcomes.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Comparison of bilateral cementless total knee arthroplasty results between patients in different BMI groups

INTRODUCTION

The aim of this study was to compare the results of cementless bilateral total knee arthroplasty (TKA) between individuals in different obesity groups.

MATERIALS AND METHODS

This was a retrospective cohort study. Patients with a body mass index (BMI) greater than 25 who underwent bilateral TKA for gonarthrosis between 2014 and 2020 and completed a minimum follow-up of 24 months were included. Age, sex, height, weight, BMI, operation time, length of stay, patient satisfaction, knee scores and complications were compared. Patients with missing data, who were followed for less than 24 months or had postoperative fractures around the knee were excluded.

RESULTS

There was a significant difference between the groups in terms of operation time (Class III > overweight > Class II > Class I p < 0.001). There was a significant difference in complications between the groups (Class III > Class I > Class II > overweight p = 0.010). According to our pairwise comparison, complications were more common in the class III group than in the overweight group. Knee score (KS) and function score (FS) increased significantly after surgery in all groups (p < 0.001), with no difference in FS (p = 0.448). Knee score changes were greater in the overweight and class I groups (p < 0.001). There was a significant interaction between both KS and FS and person satisfaction (p < 0.001).

CONCLUSION

Cementless TKA improved KS and FS in all obesity groups, yielded high patient satisfaction. Although the incidence of complications was higher in the morbidly obese patients than in the overweight patients, the difference was not significant. Patients with morbid obesity should be informed about related risks before planning cementless TKA.

The Effect of Obesity on Hemiarthroplasty and Total Hip Arthroplasty for Femoral Neck Fractures

Obesity is a well-recognized global epidemic that can lead to longer operative times as well as a greater technical demand. Despite this, the available literature evaluating the impact of obesity on hip hemiarthroplasty (HA) and total hip arthroplasty (THA) when treating fractures about the femoral neck is scarce. Between 2015 and 2018, we retrospectively reviewed all patients that had a HA or THA performed as treatment for an isolated fracture of the femoral neck. Patients were classified as obese and nonobese depending on current body mass index (BMI) when the index procedure was performed. Preoperative and postoperative variable were obtained from the electronic medical record. A total of 157 patients underwent hip HA or THA for an isolated fracture of the femoral neck. In those patients undergoing HA, obesity was associated with an increase in operative times (P = 0.021) and was associated with a nonsignificant increase in total operating room time (P = 0.088) and duration of anesthesia (P = 0.14). In those patients undergoing THA, obesity was associated with longer operative times (P = 0.043), total operating room time (P = 0.032), and duration of anesthesia (P = 0.045). There were no significant differences in complication rates postoperatively between obese and non-obese patients undergoing either procedure. The treatment of isolated fractures of the femoral neck with HA or THA leads to an increase in operative time without an increase in postoperative complications in obese patients.

Leveraging large, real-world data through machine-learning to increase efficiency in robotic-assisted total knee arthroplasty

PURPOSE

Increased operative time can be due to patient, surgeon and surgical factors, and may be predicted by machine learning (ML) modeling to potentially improve staff utilization and operating room efficiency. The purposes of our study were to: (1) determine how demographic, surgeon, and surgical factors affected operative times, and (2) train a ML model to estimate operative time for robotic-assisted primary total knee arthroplasty (TKA).

METHODS

A retrospective study from 2007 to 2020 was conducted including 300,000 unilateral primary TKA cases. Demographic and surgical variables were evaluated using Wilcoxon/Kruskal-Wallis tests to determine significant factors of operative time as predictors in the ML models. For the ML analysis of robotic-assisted TKAs (> 18,000), two algorithms were used to learn the relationship between selected predictors and operative time. Predictive model performance was subsequently assessed on a test data set comparing predicted and actual operative time. Root mean square error (RMSE), R² and percentage of predictions with an error < 5/10/15 min were computed.

RESULTS

Males, BMI > 40 kg/m² and cemented implants were associated with increased operative time, while age > 65yo, cementless, and high surgeon case volume had reduced operative time. Robotic-assisted TKA increased operative time for low-volume surgeons and decreased operative time for high-volume surgeons. Both ML models provided more accurate operative time predictions than standard time estimates based on surgeon historical averages.

CONCLUSIONS

This study demonstrated that greater surgeon case volume, cementless fixation, manual TKA, female, older and non-obese patients reduced operative time. ML prediction of operative time can be more accurate than historical averages, which may lead to optimized operating room utilization.

LEVEL OF EVIDENCE

III.

Comparison of Operative Times in Primary Bilateral Total Knee Arthroplasty Performed by a Single Surgeon

Purpose: Prolonged operative time (OT) is associated with adverse complications after total knee arthroplasty (TKA). The purpose of this study was to determine whether preoperative factors, such as sex, age, body mass index, body weight (BW), body height, American Society of Anesthesiologists grade, tibiofemoral angle, hospital for special surgery scores, surgical side, surgical order, and calendar year of surgery, affect OT. Methods: One hundred and nineteen patients (238 knees) with osteoarthritis who underwent staged bilateral primary TKA performed by a single surgeon were evaluated. The medical records of 15 males and 104 females were retrospectively reviewed. All variables were expressed as median (interquartile range). Results: The OT for all TKAs was 57 min (51, 65). The OT on the left side (59 min (52−67)) was longer than that on the right side (55 min (50−62)) (p = 0.015). Multiple regression analysis revealed that longer OT was related to BW (β = 0.488, p < 0.001), calendar year of surgery (β = −0.218, p< 0.001), and operative side (β = −0.151, p = 0.007). The Jonckheere−Terpstra test showed a trend toward decreasing OT with calendar year on the left side (p = 0.037) (surgeon’s non-dominant side), but not on the right (p = 0.795). Body height, BW, and body mass index showed weak correlations (r = 0.212, p = 0.001; r = 0.352, p < 0.001; r = 0.290, p < 0.001, respectively) with OT. Conclusion: Patients with a large physique, and especially obesity, with an affected knee on the surgeon’s non-dominant side may require a longer OT; OT decreased over time.

Predicting robotic-assisted total knee arthroplasty operating time

Aims

No predictive model has been published to forecast operating time for total knee arthroplasty (TKA). The aims of this study were to design and validate a predictive model to estimate operating time for robotic-assisted TKA based on demographic data, and evaluate the added predictive power of CT scan-based predictors and their impact on the accuracy of the predictive model.

Methods

A retrospective study was conducted on 1,061 TKAs performed from January 2016 to December 2019 with an image-based robotic-assisted system. Demographic data included age, sex, height, and weight. The femoral and tibial mechanical axis and the osteophyte volume were calculated from CT scans. These inputs were used to develop a predictive model aimed to predict operating time based on demographic data only, and demographic and 3D patient anatomy data.

Results

The key factors for predicting operating time were the surgeon and patient weight, followed by 12 anatomical parameters derived from CT scans. The predictive model based only on demographic data showed that 90% of predictions were within 15 minutes of actual operating time, with 73% within ten minutes. The predictive model including demographic data and CT scans showed that 94% of predictions were within 15 minutes of actual operating time and 88% within ten minutes.

Conclusion

The primary factors for predicting robotic-assisted TKA operating time were surgeon, patient weight, and osteophyte volume. This study demonstrates that incorporating 3D patient-specific data can improve operating time predictions models, which may lead to improved operating room planning and efficiency.

Cite this article: Bone Jt Open 2022;3(5):383–389.

Failure Analysis in Multiple TKA Revisions-Periprosthetic Infections Remain Surgeons' Nemesis

BACKGROUND

The aim of this study was to categorize reasons for failure and to analyze the survivorship of multiple total knee arthroplasty (TKA) revisions.

METHODS

The study retrospectively evaluated all multiple TKA revisions performed between 2005 and 2015 at the authors' institutions. Sixty-three patients (35 female, 28 male, age 64 ± 10 years, follow-up 55 ± 36 months) underwent a total of 157 re-revision TKA surgeries (range 2-5). The revision indications were divided up into main diagnoses. Survivorship was evaluated by mixed model analysis.

RESULTS

The main overall reason for re-revision was periprosthetic joint infection (PJI) (48%), followed by instability (12%), polyethylene wear (11%), malpositioning (8%), and aseptic loosening (8%). Survivorship shortened with an increasing number of revision surgeries (p = 0.003). While PJI was in 38% of all cases, the reason for the first revision, incidence increased constantly with the number of revisions (48% at second revision, 55% at third revision, 86% at fourth revision, and 100% at fifth revision, p = 0.022). If periprosthetic infection caused the first revision, patients showed an average of two more septic revisions at follow-up than patients with an aseptic first revision indication (p < 0.001). In 36% of cases, the reason for follow-up surgery in case of periprosthetic infection was again PJI.

CONCLUSION

The probability of survival of the implanted knee arthroplasty is significantly reduced with each subsequent revision. Periprosthetic infection is the main cause of multiple revisions.

Obesity, preoperative weight loss, and telemedicine before total joint arthroplasty: a review

The preoperative period prior to elective total joint arthroplasty (TJA) is a critical time for lifestyle interventions since a scheduled surgery may help motivate patients to lose weight. Weight loss may reduce complications associated with obesity following TJA and enable patients with severe obesity (body mass index [BMI] > 40 kg/m²) to become eligible for TJA, as many institutions use a 40 kg/m² cut-off for offering surgery. A comprehensive review was conducted to (1) provide background on complications associated with obesity following TJA, (2) synthesize prior research on the success rate of patients losing weight after being denied TJA for severe obesity, (3) discuss bariatric surgery before TJA, and (4) propose mobile health telemedicine weight loss interventions as potential weight loss methods for patients preoperatively. It is well established that obesity increases complications associated with TJA. In total knee arthroplasty (TKA), obesity increases operative time, length of stay, and hospitalization costs as well as the risk of deep infection, revision, and component malpositioning. Obesity may have an even larger impact on complications associated with total hip arthroplasty (THA), including wound complications and deep infection. Obesity also increases the risk of hip dislocation, aseptic loosening, and venous thromboembolism after THA. Synthesis of the only two studies (n = 417), to our knowledge, that followed patients denied TJA for severe obesity demonstrated that only 7% successfully reduced their BMI below 40 kg/m² via lifestyle modifications and ultimately underwent TJA. Unfortunately, bariatric surgery may only increase certain post-TKA complications including death, pneumonia, and implant failure, and there is limited research on preoperative weight loss via lifestyle modification. A review of short-term mobile health weight loss interventions that combined personalized counseling with self-monitoring via a smartphone app found about 5 kg of weight loss over 3-6 months. Patients with severe obesity have more weight to lose and may have additional motivation to do so before TJA, so weight loss results may differ by patient population. Research is needed to determine whether preoperative mobile health interventions can help patients become eligible for TJA and produce clinically significant weight loss sufficient to improve postoperative outcomes.

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.

Preoperative Nonsurgical Weight Loss Interventions Before Total Hip and Knee Arthroplasty: A Systematic Review

BACKGROUND

An upcoming total joint arthroplasty (TJA) may motivate patients with severe obesity (body mass index [BMI] > 40 kg/m²) to lose weight. Weight loss can optimize outcomes following TJA, and many surgeons use a 40 kg/m² cut-off for undergoing TJA to reduce the risk of complications. However, few patients who are denied TJA for severe obesity successfully lose weight. This is the first systematic review of nonsurgical weight loss interventions before TJA.

METHODS

Five electronic databases were searched for articles on January 11, 2021. Studies that utilized preoperative nonsurgical weight loss interventions for patients with obesity (BMI ≥ 30 kg/m²) scheduled for or awaiting TJA of the hip or knee were included. Two reviewers independently screened articles, assessed methodological quality, and extracted data.

RESULTS

We retrieved 1943 unique records, of which 7 met inclusion criteria including 2 randomized clinical trials and 5 single-arm case series. Overall, weight loss ranged from 5.0 to 32.5 kg. Four interventions reduced BMI by 3 kg/m² at 3-5 months, while 1 reduced BMI by 12.7 kg/m². Other weight outcomes and those related to pain, function, complications, and adverse events were inconsistently reported.

CONCLUSION

Although larger trials are needed, particularly randomized controlled trials that measure preoperative weight loss in a control group, nutritional status, and postoperative complications, the available evidence indicates that short-term, nonsurgical, preoperative weight loss interventions before TJA produce both statistically significant weight loss and reduced BMI before surgery. It remains unknown if the amount of weight loss from these interventions is clinically significant and sufficient to improve outcomes after TJA.

The Fate of Morbidly Obese Patients With Joint Pain: A Retrospective Study of Patient Outcomes

BACKGROUND

The number of obese patients seeking a total joint arthroplasty (TJA) continues to increase. Weight loss is often recommended to treat joint pain and reduce risks associated with TJA. We sought to determine the effectiveness of an orthopedic surgeon's recommendation to lose weight.

METHODS

We identified morbidly obese (body mass index (BMI) 40-49.9 kg/m²) and super obese (BMI ≥50 kg/m²) patients with hip or knee osteoarthritis. Patients with less than 3-month follow-up were excluded. Patient characteristics (age, gender, BMI, comorbidities), disease characteristics (joint affected, radiographic osteoarthritis grading), and treatments were recorded. Clinically meaningful weight loss was defined as weight loss greater than 5%.

RESULTS

Two hundred thirty morbid and 50 super obese patients were identified. Super obese patients were more likely to be referred to weight management (52.0% vs 21.7%, P < .001) and were less likely to receive TJA (20.0% vs 41.7%, P = .004). Each 1 kg/m² increase in BMI decreased the odds of TJA by 10.9% (odds ratio = 0.891, 95% confidence interval: 0.833-0.953, P = .001). Forty (23.0%) of the nonoperatively treated patients achieved clinically meaningful weight loss, and 19 (17.9%) patients who underwent TJA lost weight before surgery. After surgery, the number of patients who achieved a clinically meaningful weight loss grew to 32 (30.2%).

CONCLUSION

In morbid and super obese patients, increasing BMI reduces the likelihood that a patient will receive TJA, and when counseled by their orthopedic surgeon, few patients participate in weight-loss programs or are otherwise able to lose weight. Weight loss is an inconsistently modifiable risk factor for joint replacement surgery.

Greater risk of all-cause revisions and complications for obese patients in 3 106 381 total knee arthroplasties: a meta-analysis and systematic review

BACKGROUND

Obesity is a major public health issue and has considerable implications on outcomes of total knee arthroplasty (TKA). However, there has been conflicting evidence and conclusions on the effects of obesity on TKA. This meta-analysis compares the outcomes, complications, and peri-operative parameters of TKA in the obese (body mass index [BMI] ≥ 30 kg/m² ) versus non-obese (BMI < 30 kg/m² ) population as well as subgroup analysis of morbidly obese (BMI ≥ 40 kg/m² ) versus non-obese population.

METHODS

A meta-analysis was conducted with a multi-database search according to PRISMA guidelines on 12 September 2019. Data from all published literature meeting inclusion criteria were extracted and analysed.

RESULTS

Ninety-one studies were included, consisting of 917 447 obese and 2 188 834 non-obese TKA. Obese patients had higher risk of all-cause revisions (odds ratio [OR] = 1.15, 95% CI: 1.08-1.24, p < 0.0001), all complications (OR = 1.21, 95% CI: 1.06-1.38, p = 0.004), deep infections (OR = 1.47, 95% CI: 1.27-1.69, p < 0.0001), superficial infections (OR = 1.59, 95% CI: 1.32-1.91, p < 0.0001), wound dehiscence (OR = 1.46, 95% CI: 1.24-1.72, p < 0.0001) and readmissions (OR = 1.21, 95% CI: 1.05-1.40, p = 0.009). Subgroup analysis of morbidly obese patients revealed greater risks of all-cause revisions (OR = 1.25, 95% CI: 1.10-1.43, p = 0.0009), deep infections (OR = 1.98, 95% CI: 1.05-3.75, p = 0.04), superficial infections (OR = 2.44, 95% CI: 2.08-2.88, p < 0.0001) and readmissions (OR = 1.33, 95% CI: 1.20-1.47, p < 0.0001). No analysis was performed on patient reported outcome measures due to heterogeneous reporting methods.

CONCLUSION

Obese and morbidly obese patients have higher risks of revisions and infections post TKA. Surgeons should counsel patients of these risks during the informed consenting process and adopt preventative strategies into clinical practice to reduce risks where possible. In conclusion, obesity is a significant, modifiable risk factor for increased complications following TKA.

Risk Factors for Readmissions After Total Joint Replacement: A Meta-Analysis

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We performed a systematic review and meta-analysis of predictive modeling studies examining the risk of readmission after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in order to synthesize key risk factors and evaluate their pooled effects. Our analysis entailed 15 compliant studies for qualitative review and 17 compliant studies for quantitative meta-analysis.

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A qualitative review of 15 predictive modeling studies highlighted 5 key risk factors for risk of readmission after THA and/or TKA: age, length of stay, readmission reduction policy, use of peripheral nerve block, and type of joint replacement procedure.

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A meta-analysis of 17 studies unveiled 3 significant risk factors: discharge to a skilled nursing facility rather than to home (approximately 61% higher risk), surgery at a low- or medium-procedure-volume hospital (approximately 26% higher risk), and the presence of patient obesity (approximately 34% higher risk). We demonstrated clinically meaningful relationships between these factors and moderator variables of procedure type, source of data used for model-building, and the proportion of male patients in the cohort.

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We found that many studies did not adhere to gold-standard criteria for reporting and study construction based on the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) and NOS (Newcastle-Ottawa Scale) methodologies.

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We recommend that these risk factors be considered in clinical practice and future work alike as they relate to surgical, discharge, and care decision-making. Future work should also prioritize greater observance of gold-standard reporting criteria for predictive models.

Preoperative optimization to prevent periprosthetic joint infection in at-risk patients

Periprosthetic joint infection (PJI) remains an important complication with devastating consequences after total joint arthroplasties. With the increasing number of arthroplasties worldwide, the number of PJI will increase correspondingly with a significant economic burden to our healthcare system. It is likely impossible to completely eradicate PJI; hence, assessment and optimization of its risk factors to preventing such a disastrous complication will be the key. There are many strategies to prevent PJI in the preoperative, intraoperative, or postoperative phases. The preoperative assessment provides a unique opportunity to screen and diagnose underlying comorbidities and optimize modifiable risk factors before elective surgeries. In this review, we will focus on current literature in preoperative assessment of various modifiable risk factors and share the experience and practical approach in our institution in preoperative optimization to reduce PJI in total joint arthroplasties.

The relationship between obesity and primary Total Knee Replacement: A scoping review of the literature

BACKGROUND

Primary Total Knee Replacement (TKR) is one of the most commonly performed elective orthopaedic procedures globally. Many patients undergoing this type of surgery are overweight or obese. In the UK, clinical commissioning groups have imposed arbitrary Body Mass Index (BMI) thresholds for TKR surgery. Many obese patients undergoing TKR believe they will lose weight following the procedure because of increased mobility.

AIM

This paper aims to present the findings of a scoping literature review about the relationship between obesity and primary TKR and to make recommendations for clinical practice, education and policy.

METHODS

A scoping literature review investigated the impact of BMI/body weight on the need for TKR, the impact of body weight and or BMI on patient outcomes following TKR, weight loss/gain following TKR and the implications of obesity on cost of TKR.

FINDINGS

Seventy-one papers were included in the review. Seven studies reported statistically significant associations between increased BMI/obesity with the need for TKR. Thirty of the studies reported worse outcomes for obese patients compared to non-obese comparisons. Forty of the studies reported no difference between obese and non-obese participants, including some where outcomes of obese patients were better than non-obese comparisons. Eight studies reported on changes to weight before and after TKR, three of the studies reporting a higher percentage losing weight than gaining weight and four studies reporting that obese patients gained weight. The 8th study reported that morbidly obese patients largely returned to their baseline BMI postoperatively.

CONCLUSION

The findings of the review challenge the legitimacy of setting BMI thresholds to control access to TKR surgery. There is an urgent need to develop evidence based approaches to support weight loss and weight management for this group of patients. Obese patients undergoing TKR should receive specific information regarding potential additional risks of complications and poorer outcomes. There is a need for health promotion regarding the association of being overweight/obese in young adulthood and developing osteoarthritis of the knee joints requiring TKR in middle and older age.

Patient-Related Risk Factors for Unplanned 30-Day Hospital Readmission Following Primary and Revision Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Total knee arthroplasty (TKA) is a highly effective procedure for advanced osteoarthritis of the knee. Thirty-day hospital readmission is an adverse outcome related to complications, which can be mitigated by identifying associated risk factors. We aimed to identify patient-related characteristics associated with unplanned 30-day readmission following TKA, and to determine the effect size of the association between these risk factors and unplanned 30-day readmission. We searched MEDLINE and EMBASE from inception to 8 September 2020 for English language articles. Reference lists of included articles were searched for additional literature. Patients of interest were TKA recipients (primary and revision) compared for 30-day readmission to any institution, due to any cause, based on patient risk factors; case series were excluded. Two reviewers independently extracted data and carried out critical appraisal. In-hospital complications during the index admission were the strongest risk factors for 30-day readmission in both primary and revision TKA patients, suggesting discharge planning to include closer post-discharge monitoring to prevent avoidable readmission may be warranted. Further research could determine whether closer monitoring post-discharge would prevent unplanned but avoidable readmissions. Increased comorbidity burden correlated with increased risk, as did specific comorbidities. Body mass index was not strongly correlated with readmission risk. Demographic risk factors included low socioeconomic status, but the impact of age on readmission risk was less clear. These risk factors can also be included in predictive models for 30-day readmission in TKA patients to identify high-risk patients as part of risk reduction programs.

Trends and risk factors for 30-day readmissions in patients with acute cholangitis: analysis from the national readmission database

INTRODUCTION

Acute cholangitis (AC) can be associated with significant mortality and high risk of readmissions, if not managed promptly. We used national readmission database (NRD) to identify trends and risk factors associated with 30-day readmissions in patients with AC.

METHODS

We conducted a retrospective cohort study of adult patients admitted with AC from 2010-2014 and Q1-Q3 of 2015 by extracting data from NRD. Initial admission with a primary diagnosis of acute cholangitis (ICD-9 code: 576.1) was considered as the index admission and any admission after index admission was considered a readmission regardless of the primary diagnosis. Multivariable regression analyses were performed to assess the association.

RESULTS

From 52,906 AC index admissions, overall 30-day readmission rate was 21.48% without significant differences in the readmission rates across the study period. There was significant increase in the overall hospital charges for readmissions, while a significant reduction in the death rate was observed during the first readmission. Recurrent cholangitis (14%), septicemia (6.4%), and mechanical complication of bile duct prosthesis (3%) were the most common reasons for readmissions. The risk of readmission was significantly higher in patients with pancreatic neoplasm (OR 1.6, 95% CI 1.4-1.8), those who underwent percutaneous biliary procedures (OR 1.4, 95% CI 1.2-1.6), and who had an acute respiratory failure (OR 1.2, 95% CI 1.0-1.15). Other factors contributing to increased risk of readmissions included patients with Charleston comorbidity index > 3, diabetes, and length of stay > 3 days. Readmission risk was significantly lower in patients who underwent ERCP (OR 0.80, 95% CI 0.73-0.88) or cholecystectomy (OR 0.54, 95% CI 0.43-0.69).

CONCLUSIONS

AC is associated with a high 30-day readmission rate of over 21%. Patients with malignant biliary obstruction, increased comorbidities, and those who undergo percutaneous drainage rather than ERCP seem to be at the highest risk.

Choices, Compromises, and Controversies in Total Knee and Total Hip Arthroplasty Modifiable Risk Factors: What You Need to Know

BACKGROUND

Total joint arthroplasty has historically been very successful for most patients, yet some still incur a complication. In an era of value-based care, certain efforts need to be taken to optimize patients' risk profile before surgery to decrease the chances of readmission or surgical complication.

METHODS

We reviewed 10 key medical conditions and lifestyle factors that surgeons should improve before pursuing total joint arthroplasty and provide a summary of the available literature to guide certain optimization thresholds.

RESULTS

With careful attention to and the creation of a preoperative checklist, surgeons can identify key domains, including morbid obesity, malnutrition, diabetes, smoking, opioid use, poor dentition, cardiovascular disease, preoperative anemia, staphylococcus colonization, and psychological disorders and intervene based on an individual's areas of deficiencies.

CONCLUSION

By following stringent protocols and rescheduling surgery until optimization has occurred, we can work to provide patients the best chance for a successful outcome with an elective hip or knee arthroplasty.