Revision Rates and Functional Outcome Scores for Severely, Morbidly, and Super-Obese Patients Undergoing Primary Total Hip Arthroplasty

Surgical site soft tissue thickness as a predictor of complications following arthroplasty

Appreciation of soft-tissue thickness (STT) at surgical sites is an increasingly recognized aspect of arthroplasty procedures as it may potentially impacting postoperative outcomes. Recent research has focused on the predictive value of preoperative STT measurements for complications following various forms of arthroplasty, particularly infections, across procedures such as total knee, hip, shoulder, and ankle replacements. Several studies have indicated that increased STT is associated with a higher risk of complications, including infection and wound healing issues. The assessment of STT before surgery could play a crucial role in identifying patients at a higher risk of complications and may be instrumental in guiding preoperative planning to optimize outcomes in arthroplasty procedures. Standardized measurement techniques and further research are essential to enhance the reliability and clinical utility of STT assessment for arthroplasty surgery.

A survey of Scottish Committee for Orthopaedics and Trauma members on lower limb joint replacement practices in morbidly obese patients

Background

Scotland has one of the highest rates of obesity in the developed world which increases risk of lower limb osteoarthritis resulting in total joint arthroplasty (TJA). This paper aimed to investigate (1) current practice of orthopaedic consultants in Scotland in managing end-stage hip and knee osteoarthritis in obese patients, (2) adherence to National guidelines, and (3) understanding of complication risks in lower limb TJA for BMI≥40.

Methods

A 15-question online survey was sent to all active members of Scottish Committee for Orthopaedics and Trauma (SCOT) between February and March 2023 to understand the current practices for managing obese patients with lower limb arthritis requiring joint replacement surgery.

Results

The survey received 62 responses from members of SCOT. The experience ranges from 1 to 44 years (mean 15 years) at consultant level. 61 % of respondents were aware of the SCOT National Guidelines for lower limb TJA in obese patients. 72 % would offer TJA to patients with a BMI>40.35 % would get a second opinion and 22 % discuss these cases in a multidisciplinary team meeting. 71 % were aware of the local weight management guidelines. 77 % quoted risk of deep infection to be between 1 and 30 %, and 40 % quoted risk of amputation between .002 % and 10 % in morbidly obese patients.

Conclusion

Surgical management of obese patients with lower limb osteoarthritis in Scotland is variable. A standardised approach would be beneficial in obtaining informed consent.

[Perioperative management of obese patients undergoing elective hip and knee arthroplasty]

INTRODUCTION

Obesity is a worldwide growing health crisis, affecting younger and younger age groups and posing new challenges for arthroplasty. Due to increased complication rates in this population, many authors are of the opinion that in patients with a body mass index (BMI) of over 40, the problems outweigh the benefits of surgery and that surgery should be postponed until significant weight reduction has been achieved.

MATERIALS AND METHODS

A systematic review of electronic databases (PubMed, Embase, Web of Science and the Cochrane Library) was performed. 49 relevant articles were analyzed. Pre-defined questions were answered based on the literature. The level of evidence for the recommendation was defined in a consensus meeting.

RESULTS

Obese patients with a BMI ≥ 30 have an up to threefold increased perioperative risk, particularly for infections and mechanical complications. In addition, surgery in obese patients is technically demanding, which results in a higher risk of implant malpositioning. Despite these risks, obese patients benefit from surgery in a similar way compared to normal-weight patients, showing comparable improvements in function and quality of life. Preoperative weight loss can reduce the risk but should be long-term to avoid negative metabolic effects. Bariatric surgery and drug therapies can help, but their effects on perioperative risk are unclear. Besides the BMI, careful diagnosis and treatment of comorbidities is crucial.

CONCLUSION

Obese patients benefit from arthroplasty in a similar way to normal-weight patients but have a higher risk of complications, particularly infection. Prior to joint replacement, patients with a BMI of 40 or more should undergo dietary counselling and weight reduction; their metabolic status should be checked, as malnutrition can increase the risk. If weight reduction is not achieved despite these measures, the operation can be performed with increased risks, whereby the patient should be fully informed and involved in the decision-making process.

Should Body Mass Index Be Considered a Hard Stop for Total Joint Replacement?: An Ethical Dilemma

Total joint arthroplasty (TJA) is one of the most common surgeries performed in the United States and is a durable and effective option in managing osteoarthritis of the hip and knee. Recent research regarding the procedure has focused on preoperative optimization and weight loss in particular. Obesity has been shown in prior studies to increase risks associated with TJA, and, as a result, debate has focused on whether a body mass index (BMI) cutoff is a prudent tool for preoperative optimization. This article discusses the ethical dilemma of instituting a BMI cutoff and reviews current literature regarding the topic.

Is Preoperative Weight Reduction in Patients Who Have Body Mass Index ≥ 40 Associated With Lower Complication Rates After Primary Total Hip Arthroplasty?

BACKGROUND

Given the heightened risk of postoperative complications associated with obesity, delaying total hip arthroplasty (THA) in patients who have a body mass index (BMI) > 40 to maximize preoperative weight loss has been advocated by professional societies and orthopaedic surgeons. While the benefits of this strategy are not well-understood, previous studies have suggested that a 5% reduction in weight or BMI may be associated with reduced complications after THA.

METHODS

We identified 613 patients who underwent primary THA in a single institution during a 7-year period and who had a BMI >40 recorded from 9 to 12 months prior to surgery. Subjects were stratified into 3 cohorts based on whether their baseline BMI decreased by >5% (147 patients, 24%), was unchanged ( ± 5%) (336 patients, 55%), or increased by >5% (130 patients, 21%) on the day of surgery. The frequency of 90-days Hip Society and Centers for Medicare & Medicaid Services complications was compared between these cohorts. There were significant baseline differences between the cohorts with respect to baseline American Society of Anesthesiologists class (P < .001) and hemoglobin A1C (P = .011), which were accounted for in a multivariate regression analysis.

RESULTS

In univariate analysis, there was a lower incidence of readmission (P = .025) and total complications (P = .005) in the increased BMI cohort. The overall complication rate was 18.4% in the decreased BMI cohort, 17.6% in the unchanged cohort, and 6.2% in the increased cohort. However, multivariable regression analysis controlling for potential confounders did not find that preoperative change in BMI was associated with differences in 90-days complications between cohorts (P > .05).

CONCLUSIONS

Patients who have a BMI >40 and achieved a clinically significant (>5%) BMI reduction prior to THA did not have a lower risk of 90-days complications or readmissions. Thus, delaying THA in these patients to encourage weight loss may result in restricting access to a beneficial surgery without an appreciable safety benefit.

Obesity Severity Does Not Associate With Rate, Timing, or Invasiveness of Early Reinterventions After Total Knee Arthroplasty

BACKGROUND

The use of body mass index (BMI) cutoff values has been suggested for proceeding with total knee arthroplasty (TKA) in obese patients. However, the relationship between obesity severity and early reoperations after TKA is poorly defined. This study evaluated whether increased World Health Organization (WHO) obesity class was associated with risk, severity, and timing of reintervention within one year after TKA.

METHODS

There were 8,674 patients from our institution who had a BMI ≥ 30 and underwent unilateral TKA for primary osteoarthritis between 2016 and 2021. Patients were grouped by WHO obesity class: 4,456 class I (51.5%), 2,527 class II (29.2%), and 1,677 class III (19.4%). A chart review was performed to determine patient characteristics and identify patients who underwent any closed or open reintervention requiring anesthesia within the first postoperative year. Regression analyses were performed to identify variables associated with increased odds ratios (ORs) for requiring a reintervention, its timing, and invasiveness.

RESULTS

There were 158 patients (1.8%) who required at least one reintervention, and 15 patients (0.2%) required at least 2 reinterventions. Reintervention rates for obesity classes I, II, and III were 1.8% (n = 81), 2.0% (n = 51), and 1.4% (n = 23), respectively. There were 65 closed procedures (41.1%), 47 minor procedures (29.7%), 34 open with or without liner exchange (21.5%), and 12 revisions with component exchange (7.6%). Obesity class was not associated with reintervention rate (P = .3), timing (P = .36), or invasiveness (P = .93). Diabetes (odds ratio [OR] = 2.47; P = .008) was associated with a need for reintervention. Non-Caucasian race (OR = 1.7; P = .01) and Charlson comorbidity index (OR = 2.1; P = .008) were associated with earlier reintervention. No factors were associated with the invasiveness of reintervention.

CONCLUSIONS

The WHO obesity class did not associate with rate, timing, or invasiveness of reintervention after TKA in obese patients. These findings suggest that policies that restrict the indication for elective TKA based only on a BMI limit have limited efficacy in reducing early reintervention after TKA in obese patients.

LEVEL OF EVIDENCE

III.

Preoperative Laboratory Values Predicting Periprosthetic Joint Infection in Morbidly Obese Patients Undergoing Total Hip or Knee Arthroplasty

BACKGROUND

Morbidly obese patients are an ever-growing high-risk population undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) for end-stage osteoarthritis. This study sought to identify preoperative laboratory values that may serve as predictors of periprosthetic joint infection (PJI) in morbidly obese patients undergoing THA or TKA.

METHODS

All morbidly obese patients with preoperative laboratory data before undergoing primary elective TKA or THA were identified using the Premier Healthcare Database. Patients who developed PJI within 90 days after surgery were compared with patients without PJI. Laboratory value thresholds were defined by clinical guidelines or primary literature. Univariate and multivariable regression analyses were utilized to assess the association between PJI and preoperative laboratory values, including total lymphocyte count, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), albumin level, platelet count, albumin-globulin ratio, hemoglobin level, and hemoglobin A1c.

RESULTS

Of the 6,780 patients identified (TKA: 76.67%; THA: 23.33%), 47 (0.69%) developed PJI within 90 days after surgery. The rate of PJI was 1.69% for patients with a hemoglobin level of <12 g/dL (for females) or <13 g/dL (for males), 2.14% for those with a platelet count of <142,000/µL or >417,000/µL, 1.11% for those with an NLR of >3.31, 1.69% for those with a PLR of >182.3, and 1.05% for those with an SII of >776.2. After accounting for potential confounding factors, we observed an association between PJI and an abnormal preoperative NLR (adjusted odds ratio [aOR]: 2.38, 95% confidence interval [CI]: 1.04 to 5.44, p = 0.039), PLR (aOR: 4.86, 95% CI: 2.15 to 10.95, p < 0.001), SII (aOR: 2.44, 95% CI: 1.09 to 5.44, p = 0.029), platelet count (aOR: 3.50, 95% CI: 1.11 to 10.99, p = 0.032), and hemoglobin level (aOR: 2.62, 95% CI: 1.06 to 6.50, p = 0.038).

CONCLUSIONS

This study identified preoperative anemia, abnormal platelet count, and elevated NLR, PLR, and SII to be associated with an increased risk of PJI among patients with a body mass index of ≥40 kg/m 2 . These findings may help surgeons risk-stratify this high-risk patient population.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Short stem hip arthroplasty with the optimys prosthesis is a safe and effective option for obese patients: a mid-term follow-up multicenter study

INTRODUCTION

Short stems are a valuable option in young patients undergoing total hip arthroplasty (THA) because of their bone stock preserving properties facilitating revision hip arthroplasty. Although the effect of obesity on conventional THA is well studied, data about short stem THA in obese patients are lacking. Therefore, this study aimed to investigate the influence of obesity on complications, revisions, and outcome after short stem THA.

MATERIALS AND METHODS

This multicenter, observational cohort study included patients undergoing short stem THA with the optimys prosthesis. Follow-up examinations were performed at specific intervals up to 7 years postoperatively. Operation characteristics, general and specific complications, revisions, VAS rest pain, VAS load pain, VAS patient satisfaction, and Harris Hip Score (HHS) were recorded and statistically compared between obese (BMI ≥ 30 kg/m2) and non-obese (BMI < 30 kg/m2) patients.

RESULTS

Of the 224 patients included with a mean follow-up of 87.2 months (range 81.9-104.0), 69 were assigned to the OB group and 155 to the non-OB group. A minimally invasive approach was significantly less often selected in obese patients (p = 0.049), whereas operating time and length of hospital stay were not significantly different. The rate of general and specific complications did not significantly differ between both groups. Survival of the optimys prosthesis was 99.1% at 7-year follow-up and one patient per group had to undergo revision surgery. VAS rest pain, load pain, and satisfaction improved from preoperatively to postoperatively in both groups without a significant difference between both groups. While the HHS was improved from preoperatively to postoperatively, obese patients showed a significantly lower HHS at the 7-year follow-up (p = 0.01) but still exhibited an excellent scoring above the PASS threshold.

CONCLUSION

Short stem THA with the optimys prosthesis is a safe and effective option also in obese patients with an excellent clinical outcome and a low complication rate.

The Impact of Obesity on Total Hip Arthroplasty Outcomes When Performed by High-Volume Surgeons-A Propensity Matched Analysis From a High-Volume Urban Center

BACKGROUND

Previous data suggest that obesity does not impact surgical outcomes following total knee arthroplasty performed by high-volume (HV) surgeons. However, this effect has yet to be studied in total hip arthroplasty (THA) patients. This study aimed to evaluate the impact of patient obesity on THA outcomes when surgery is performed by HV surgeons.

METHODS

A retrospective analysis of patients who underwent primary, elective THA between January 2012 and December 2022 with a HV surgeon (top 25% of surgeons by number of annual primary THA) was performed. Patients were stratified by their body mass index (BMI) into 3 cohorts: BMI ≥ 40 (morbidly obese [MO]), 30 ≤ BMI < 40 (obese), and BMI < 30 (nonobese); and 1:1:1 propensity matched based on baseline characteristics. A total of 13,223 patients were evaluated, of which 669 patients were included in the final matched analysis (223 patients per group). The average number of annual THAs performed for HV surgeons was 171 cases.

RESULTS

The MO patients had significantly longer surgical times (P < .001) and hospital lengths of stay (P < .001). Rates of 90-day readmissions (P = .211) and all-cause, septic, and aseptic revisions at the latest follow-up (P = .268, P = .903, and P = .168, respectively) were comparable between groups. In a subanalysis for non-HV surgeons, MO patients had a significantly greater risk of revision (P = .021) and trended toward significantly greater readmissions (P = .056).

CONCLUSIONS

Clinical outcomes and complication rates after THA performed by a HV surgeon are similar regardless of patient obesity status. Patients who have MO may experience improved outcomes and reduced procedural risks if they are referred to HV surgeons.

LEVEL OF EVIDENCE

III.

Sex-specific differences in 30-day outcomes following primary total hip replacement in 86,684 patients

INTRODUCTION

Although differential outcomes based on sex are widespread in medicine and surgery, evaluation of sex-specific differences in the field of orthopaedic surgery in general - and arthroplasty in particular - are lacking. We hypothesised that morbidly obese male and female patients would have differing risks of surgical complications following primary total hip replacement.

METHODS

We reviewed data contained within the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database from 2015 through 2018, inclusive. A multivariable binary logistic regression model was used to determine the adjusted odds ratios (OR) of relevant variables on primary and secondary outcomes.

RESULTS

A total of 86,684 patients undergoing THR were identified, of whom 9972 patients (4095 male and 5877 female) were morbidly obese. Among morbidly obese patients, odds of surgical site infection were higher in females than males within 30 days of surgery (adjusted OR 1.40; 95% CI, 1.10-1.79; p = 0.007). This comprised the odds of both superficial infection (1.8% vs. 1.1%, adjusted OR 1.67; 95% CI, 1.16-2.40; p = 0.006) and deep infection (1.9% vs. 1.4%, adjusted OR 1.22; 95% CI, 0.88-1.68; p = 0.24). Unexpected return to the operating room (i.e., reoperation) within 30 days of the surgical procedure was also higher among females than males (4.2% vs. 3.1%, adjusted OR 1.38, 95% CI, 1.10-1.71, p = 0.005). There were no differences between male and female patients in the non-obese cohort.

CONCLUSIONS

Among patients with morbid obesity, the risk of surgical site infection and reoperation within the first 30 days is greater in women as compared to men. Future research must address whether this early increased risk among morbidly obese women persists in the longer term, and whether it results in compromised function or quality of life.

Outcomes of total hip and knee arthroplasty in special populations: a synopsis and critical appraisal of systematic reviews

INTRODUCTION

This study aimed to present and critically appraise the best available evidence investigating associations between some pre-defined patient-related characteristics and perioperative complications or other outcomes in THA and TKA.

METHODS

Electronic databases were searched (Medline, EMBASE, Scopus, CENTRAL) for systematic reviews assessing the following pre-defined patient-related characteristics as possible risk factors for worse peri-operative outcomes in THA and TKA: smoking, alcohol excess, rheumatoid arthritis, human immunodeficiency virus infection, hepatitis C virus infection, mental health conditions, and solid organ transplantation. Our primary outcome was periprosthetic joint infection. Results were analysed separately for THA, TKA and THA/TKA (mixed data).

RESULTS

Based on at least two systematic reviews being in agreement, the following patient-related characteristics were associated with increased incidence of complications as follows: a) Smoking for all-cause revision in THA, for periprosthetic joint infection in TKA and THA/TKA; b) alcohol excess for periprosthetic joint infection in THA/TKA; c) human immunodeficiency virus for periprosthetic joint infection in THA/TKA; d) hepatitis C virus for overall complications, periprosthetic joint infection and all-cause revision in THA and THA/TKA, and for overall complications in TKA. Our study found conflicting evidence for a) smoking as a risk factor for periprosthetic joint infection and aseptic loosening in THA; b) human immunodeficiency virus as a risk factor for all-cause revision for THA/TKA; c) hepatitis C virus as a risk factor for periprosthetic joint infection and all-cause revision in TKA. No certainty of evidence was assigned to these results as this was not assessed by the authors of the majority of the included systematic reviews.

CONCLUSION

We found that smoking, excess alcohol consumption, RA, and infection with HIV and HCV were associated with a higher incidence of periprosthetic joint infection in one or both of THA and TKA or mixed THA/TKA data. All our results should be interpreted and communicated to patients with caution as the quality of the included systematic reviews was generally poor.

Risk Factors for Failure of Total Ankle Replacements: A Data Linkage Study Using the National Joint Registry and NHS Digital

BACKGROUND

Despite the increasing numbers of ankle replacements, there remains debate about which patients should undergo an ankle replacement, and there are limited studies analyzing risk factors for failure of an ankle replacement. The primary aim of this study is to analyze the risk factors for failure of total ankle replacements.

METHODS

A data linkage study combining the National Joint Registry (NJR) Data and NHS (National Health Service) Digital data was performed. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device. Kaplan-Meier survival charts were used to illustrate survivorship. Multivariable Cox proportional hazards regression models were fitted to analyze potential risk factors for failures or ankle replacements.

RESULTS

The overall 5-year survival was 90.2% (95% CI 89.2%-91.1%). In multivariable (adjusted) Cox regression models, only age (hazard ratio [HR] 0.96, 95% CI 0.94-0.97), body mass index (BMI; HR 1.03, 95% CI 1.01-1.06), and underlying etiology (HR 0.88, 95% CI 0.80-0.97) were associated with an increased risk of failure.

CONCLUSION

This study demonstrates that younger patients and those with an increased BMI have an increased risk of failure of a primary ankle replacement. We also show that rheumatoid patients have higher survivorship than those with osteoarthritis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Function and employment after total hip replacement in older adults: A narrative review

The burden of osteoarthritis (OA) has increased steadily due to an aging population, increasing life expectancy, obesity and lifestyle factors. Total hip replacement has become one of the most prevalent and successful operations globally and it is projected that demand will continue to grow as the incidence of OA continues to increase. Patients undergoing the operation expect much-improved function and pain relief but also increasingly need to return to work postoperatively, especially given the growing demand for the procedure and the encouragement of older people to continue working by most governments in the developed world. This review provides an overview of function and employment outcomes after hip arthroplasty. Despite the generally good success rate, some patients do not attain good functional outcomes and it is important that we develop ways to identify these patients preoperatively. We describe the effect of demographic, clinical and other factors on functional outcomes, as well as trajectories of physical function and pain recovery beyond the first few weeks after total hip replacement. Regarding employment outcomes, many people in work preoperatively are likely to resume to work after recovery; however, patients feel that they lack guidance from clinicians about returning to work postoperatively. Our review encompasses factors associated with return to work, timing of return to work, and potential temporary or permanent limitations that people might experience at work depending on type of employment.

Does body mass index influence long-term outcomes after anatomic total shoulder arthroplasty?

BACKGROUND

As of 2018, upwards of 42% of the US adult population was considered obese based on body mass index (BMI) scales. With the annual number of total joint replacements increasing, this study aimed to evaluate the impact BMI has on anatomic total shoulder arthroplasty (aTSA) outcomes.

METHODS

This was a retrospective analysis of 128 shoulders requiring primary aTSA. Patients were stratified into 3 cohorts based on their BMI at surgery: underweight/normal weight (U/NW; BMI ≤25.0), overweight (25.0 < BMI ≤ 30.0), and obese (BMI >30.0). BMI was separately analyzed as a continuous variable. Clinical endpoints were range of motion scores, including forward elevation, external rotation, and internal rotation, and patient-reported outcomes, including visual analog scale (VAS) scores, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores, and the Simple Shoulder Test (SST). Survivorship curves were calculated using Kaplan-Meier analysis.

RESULTS

Forty-four, 50, and 34 patient shoulders were in the U/NW, overweight, and obese cohorts, respectively. The mean follow-up time was 11.4 years. The U/NW cohort had more females (73%) compared with the overweight (34%; P = .0030) and obese (35%; P = .0015) groups; no differences were seen in revision rates. BMI was negatively correlated with age at surgery (r = -0.19, P = .014); it was not correlated with any of the 6 postoperative clinical endpoints. All 3 cohorts saw significant improvements in forward elevation, external rotation, internal rotation and VAS, ASES, and SST scores when compared preoperatively to postoperatively (P < .001). There were no significant differences between the 3 cohorts with respect to postoperative range of motion. Postoperative ASES scores were higher for the overweight cohort (82.6 ± 18.6) compared with both the U/NW (63.0 ± 25.1) and obese cohorts (70.5 ± 26.8) (P < .001). The overweight cohort also had higher SST (P = .0012) postoperative scores compared with the U/NW and obese cohorts; VAS scores were comparable between groups (P = .12). The nonobese (BMI <30) group (n = 94) showed 5-, 10-, and 15-year implant survival of 98.9%, 94.9%, and 83.9%, respectively compared to 97.1%, 93.7%, and 87.0% in the obese (BMI ≥30) group (n = 34). The log rank test revealed no significant difference in survival curves (P = .82).

CONCLUSION

To our knowledge, this is the longest follow-up study analyzing clinical endpoints stratified by BMI for aTSA. We saw that patients with a higher BMI required shoulder replacement at a significantly younger age. However, we also report that regardless of BMI, all patients saw significant improvements in patient-reported outcomes and range of motion scores postoperatively.

The Impact of Obesity on Total Hip Arthroplasty Outcomes: A Retrospective Matched Cohort Study

Aim

Previous research has shown that obesity is associated with worse postoperative outcomes. We aim to determine how rates of specific complications after total hip arthroplasty (THA) align with obesity status. We hypothesize that obese patients would have higher rates of complications and cost and thus have worse outcomes than non-obese patients.

Methods

Data were collected from a large commercial insurance database between 2011 and 2020. Patients underwent a hip replacement under current procedural terminology (CPT) and International Statistical Classification of Diseases (ICD-9/ICD-10) codes. Obese (defined as having a BMI of 30 kg/m² or higher) and non-obese patients were matched on age, gender, Charlson Comorbidity Index (CCI), and Elixhauser Comorbidity Index (ECI). Standardized complications and costs in one year were compared using unequal variance t-tests.

Results

Under CPT codes, 61,462 obese (45% male) and 61,462 non-obese patients (45% male) underwent a hip replacement. Obese patients had significantly higher rates of surgical site infection (SSI) (OR=1.193, p=0.0001), deep vein thrombosis (DVT) (OR=1.275, p=0.001), wound complication (OR=1.736, p<0.0001), hematoma (OR=1.242, p=0.0001), pulmonary embolism (OR=1.141, p=0.0355), UTI (OR=1.065, p=0.0016), and opioid prescriptions (OR=1.17, p<0.0001), and significantly lower rates of arrhythmia (OR=0.907, p<0.0001), congestive heart failure (CHF) (OR=0.863, p<0.0001), cardiac arrest (OR=0.637 p<0.0001), pneumonia (OR=0.795, p<0.0001), and transfusion (OR=0.777, p<0.0001). Furthermore, obese patients were significantly more likely to undergo revision within 10 years (OR=1.172, p<0.0001). Under ICD codes, 31,922 obese (45% male) and 31,922 non-obese patients (45% male) were included. Obese patients did not have a significant difference in total cost or drug cost.

Conclusions

Obese patients had significantly higher rates of infection, venous thromboembolic event, wound complication, hematoma, and opioid prescriptions but significantly lower rates of cardiac issues, pneumonia, and transfusion, after hip replacement. Additionally, there was no significant difference in total or drug cost. Therefore, this study did not support our hypothesis that obese patients have worse outcomes than non-obese patients, as there neither was a clear significant increase in complication rates nor a significant increase in costs. However, further research should be done to better understand the complex relationship between obesity and postoperative outcomes.

Patterns and Predictors of Weight Change Before and After Total Hip Arthroplasty in Class 2 and 3 Obese Patients

BACKGROUND

This study aimed to better understand body mass index (BMI) change patterns and factors associated with BMI change before and after total hip arthroplasty (THA) in Class 2 and 3 obese patients, and assess if preoperative or postoperative BMI change affects postoperative clinical outcomes.

METHODS

We retrospectively reviewed World Health Organization Class 2 and 3 obese patients (BMI > 35.0 at surgery) who underwent THA at a tertiary medical center from 2010 to 2020. BMI was recorded at 1 year preoperatively (mean 11.6 months), and at most recent postoperative visit (mean 29.0 months). Baseline demographics and postoperative clinical outcomes were recorded.

RESULTS

We reviewed 436 THAs with a mean age of 59.9 (11.5) years. Leading up to surgery 55.5% had unchanged BMI, and postoperatively 48.2% had unchanged BMI. Multivariate logistic regression revealed that those who lost BMI preoperatively were more likely to gain BMI postoperatively (odds ratio [OR] 3.28, confidence interval [CI] 1.83-5.97, P = .005), but those who gained >5% BMI preoperatively had no association with BMI change postoperatively. Those in a higher BMI class preoperatively were less likely to gain BMI preoperatively (Class 3 obese patients: OR 0.001, CI 0.0002-0.004, P < .001). African American patients were more likely to gain BMI preoperatively (OR 2.32, CI 1.16-4.66, P = .017). We did not detect an association between BMI change and postoperative clinical outcomes.

CONCLUSION

In World Health Organization Class 2 or 3 obese patients, most maintained BMI between their first preoperative and final postoperative visit. Preoperatively, Class 3 obese patients were less likely to gain weight than Class 2 obese patients. The primary predictor of postoperative weight gain was preoperative weight loss. Weight change preoperatively and postoperatively were not associated with worse clinical outcomes.

Obesity, Comorbidities, and Prior Operations Additively Increase Failure in 2-Stage Revision Total Knee Arthroplasty for Prosthetic Joint Infection

BACKGROUND

Prosthetic joint infection (PJI) of the knee carries significant morbidity, mortality, and economic cost. We hypothesize that obese and poor medical hosts will have a significant and additive increase in failure rate undergoing 2-stage revision total knee arthroplasty for PJI.

METHODS

All 2-stage revision total knee arthroplasty procedures for PJI performed at one institution were identified between 2005 and 2020. In total, 144 patients were included and defined as success or failure based on published criteria regarding infection eradication, further intervention, or mortality. The American Society of Anesthesiologists score and the Charlson Comorbidity Index were utilized to assess host grade. Patient, surgical, and microbiologic variables were investigated with univariable and multivariable analysis to explore association with risk of failure.

RESULTS

In the cohort, 32.4% of patients failed with mean follow-up of 5.1 years. In multivariable analysis, the number of major operations requiring arthrotomy and implantation of new material between the primary and first stage, host grade, and elevated body mass index were the major contributors to failure. Combining these factors, with body mass index >30 and 2 or more major operations, the failure rate increased to 76.5% and 71.4% respectively for American Society of Anesthesiologists score 3 (P ≤ .001) and Charlson Comorbidity Index ≥2 (P ≤ .001).

CONCLUSION

In this cohort, multiple major operations between the primary and first stage, host grade, and obesity were the major contributors to failure. When combining these factors, patients had an additive increase in failure rate. Treatments such as amputation or less invasive options and suppression should be discussed and considered in these patients.

EFORT recommendations for off-label use, mix & match and mismatch in hip and knee arthroplasty

Off-label use is frequently practiced in primary and revision arthroplasty, as there may be indications for the application of implants for purposes outside the one the manufacturers intended.

Under certain circumstances, patients may benefit from selective application of mix & match. This can refer to primary hip arthroplasty (if evidence suggests that the combination of devices from different manufacturers has superior results) and revision hip or knee arthroplasty (when the exchange of one component only is necessary and the invasiveness of surgery can be reduced).

Within the EFORT ‘Implant and Patient Safety Initiative’, evidence- and consensus-based recommendations have been developed for the safe application of off-label use and mix & match in primary as well as revision hip and knee arthroplasty.

Prior to the application of a medical device for hip or knee arthroplasty off-label and within a mix & match situation, surgeons should balance the risks and benefits to the patient, obtain informed consent, and document the decision process appropriately.

Nevertheless, it is crucial for surgeons to only combine implants that are compatible. Mismatch of components, where their sizes or connections do not fit, may have catastrophic effects and is a surgical mistake.

Surgeons must be fully aware of the features of the components that they use in off-label indications or during mix & match applications, must be appropriately trained and must audit their results.

Considering the frequent practice of off-label and mix & match as well as the potential medico-legal issues, further research is necessary to obtain more data about the appropriate indications and outcomes for those procedures.

Cite this article: EFORT Open Rev 2021;6:982-1005. DOI: 10.1302/2058-5241.6.210080

Clinical Practice Guideline: Total Hip Replacement for Osteoarthritis–Evidence-Based and Patient-Oriented Indications

BACKGROUND

Total Hip Replacement (THR) belongs to the most common inpatient operations in Germany, with over 240 000 procedures performed per year. 90% of the artificial joints are still functional at 15 years, and up to 60% at 20 years after surgery. It is essential that the indications for such procedures should be uniform, appropriate, and patient-oriented.

METHODS

This review is based on publications retrieved by a systematic literature search for national and international guidelines and systematic reviews on the topic of hip osteoarthritis and THR.

RESULTS

THR should be performed solely with radiologically demonstrated advanced osteoarthritis of the hip (Kellgren and Lawrence grade 3 or 4), after at least three months of conservative treatment, and in the presence of high subjective distress due to symptoms arising from the affected hip joint. Contraindications include refractory infection, acute or chronic accompanying illnesses, and BMI ≥ 40 kg/m2. Patients should stop smoking at least one month before surgery. In patients with diabetes mellitus, preoperative glycemic control to an HbA1c value below 8% is advisable. It is recommended that patients should lower their weight below a BMI of 30 kg/m2.

CONCLUSION

The decision to perform THR should be taken together by both the physician and the patient when the expected treatment benefit outweighs the risks. Evidence suggests that a worse preoperative condition is associated with a poorer surgical outcome.

Lower Extremity Girth Does Not Predict Complications in TKA

BACKGROUND

Obese patients have increased complications after total knee arthroplasty (TKA). A body mass index (BMI) cutoff of 40 is frequently used to determine eligibility for TKA. Patients with a BMI <40 and extremely large legs which may predispose them to complications are approved for surgery because they fall below this cutoff. Alternatively, patients with truncal obesity and a BMI >40 are accepted because they have thin legs. We sought to determine whether BMI or girth should be used to determine eligibility.

METHODS

453 patients who underwent TKA were included. A lower extremity girth (LEG) ratio was calculated dividing the width of the soft tissue envelope by bone width on lateral radiographs. Receiver operator curves were generated to predict 90-day complications.

RESULTS

There was no difference in median LEG ratio between patients with or without a complication (P = .08). Receiver operator curves indicated that size of the soft tissue envelope had no utility in predicting complications. There was no correlation between LEG ratio and specific complications such as infection, malalignment, or wound complications. Using a LEG ratio threshold of 4.834, the sensitivity and specificity for predicting complications were 48% and 64%, respectively. The median BMI for patients with no complication was 32.3 and 35 for patients with a complication (P = .07).

CONCLUSION

Complications are not necessarily associated with size of the soft tissue envelope in TKA.Decisions concerning TKA should not be made solely on the size of a patient's leg.

LEVEL OF EVIDENCE

Level III (retrospective comparative study).

Complications and 30-Day Mortality Rate After Hip Fracture Surgery in Superobese Patients

OBJECTIVE

Paradoxically, overweight and obesity are associated with lower odds of complications and death after hip fracture surgery. Our objective was to determine whether this "obesity paradox" extends to patients with "superobesity." In this study, we compared rates of complications and death among superobese patients with those of patients in other body mass index (BMI) categories.

METHODS

Using the National Surgical Quality Improvement Program database, we identified >100,000 hip fracture surgeries performed from 2012 to 2018. Patients were categorized as underweight (BMI <18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9), obese (BMI 30-39.9), morbidly obese (BMI 40-49.9), or superobese (BMI ≥50). We analyzed patient characteristics, surgical characteristics, and 30-day outcomes. Using multivariate regression with normal-weight patients as the referent, we determined odds of major complications, minor complications, and death within 30 days by BMI category.

RESULTS

Of 440 superobese patients, 20% had major complications, 33% had minor complications, and 5.2% died within 30 days after surgery. When comparing patients in other BMI categories with normal-weight patients, superobese patients had the highest odds of major complications [odds ratio (OR): 1.6, 95% confidence interval (CI), 1.2-2.0] but did not have significantly different odds of death (OR: 0.91, 95% CI, 0.59-1.4) or minor complications (OR: 1.2, 95% CI, 0.94-1.4).

CONCLUSION

Superobese patients had significantly higher odds of major complications within 30 days after hip fracture surgery compared with all other patients. This "obesity paradox" did not apply to superobese patients.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a Complete Description of Levels of Evidence.

[Decision for total hip arthroplasty-the surgeons' view]

BACKGROUND

The decision for total hip arthroplasty (THA) is based on pain, loss of function, radiological changes and failed conservative therapy. These criteria are rarely based on systematic research and have not been integrated in generally accepted treatment guidelines. Aim of our study was, therefore, to analyse which decision criteria German orthopaedic and trauma surgeons use in order to recommend THA for patients with hip osteoarthritis.

MATERIALS AND METHODS

From 10/2019 to 07/2020 we conducted a nation-wide survey among 218 orthopaedic and trauma surgeons about their criteria for and against THA surgery, as well as their treatment objectives.

RESULTS

147 fully completed questionnaires were analysed. Pain (99%), limitation of movement (99%), as well as impairment of walking distance (97%), and the subjective burden (97%) were the most frequent criteria. 97% and 96% of surgeons consider prescription of analgesics and physical therapy, as well as a lack of their effectiveness, as criteria for THA. 87% see radiological changes grade Kellgren & Lawrence III as threshold. A recommendation against surgery is triggered by obesity (BMI ≥ 40 kg/m²) in 48% and by the presence of an active infection in 96%.

CONCLUSIONS

Current surgeons' practice criteria of recommendations for THA in Germany seem to reflect widely nationally and internationally discussed recommendations. Particular attention is given to patient factors like pain, loss of function and subjective burden, as well as previous conservative treatment and contraindications, like poorly controlled diabetes or an active infection, whereas morbid obesity is not seen as contraindication by all surgeons.

Outcomes of outpatient total hip arthroplasty: a systematic review

INTRODUCTION

Similar to other total joint arthroplasty procedures, total hip arthroplasty (THA) is shifting to an outpatient setting. The purpose of this study was to analyse outcomes following outpatient THA.

METHODS

A comprehensive literature search was performed in April 2019 according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines using the PubMed, Embase, and Cochrane databases to identify articles that reported functional outcomes following outpatient total hip arthroplasty (THA).

RESULTS

9 articles, with 683 hips and a collective study period of 1988 to 2016, were included in this analysis. The mean age across all studies was 58.9 years and the follow-up period ranged from 4 weeks to 10 years. 4 studies reported Harris Hip Scores (HHSs) for their patient populations and in 3 studies, the average HHSs were excellent (>90) by 6 weeks postoperatively. The fourth study reported fair HHS scores for the outpatient and inpatient THA groups (75 ± 18, 75 ± 14, p = 0.77, respectively) at 4 weeks postoperatively. VAS scores improved significantly in two studies and NRS at rest and during activity improved significantly (p < 0.001) in a separate study. Overall, 88.1% of the enrolled patients were discharged the same day of surgery, as expected. Out of the 6 studies reporting on readmissions rate, there were two (0.34%) readmissions within 3 months of surgery.

CONCLUSION

In patients with no significant comorbidities, outpatient THA leads to favourable outcomes as well as low readmission rates in the short term.

Revision Rates and Functional Outcomes Among Severely, Morbidly, and Super-Obese Patients Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity has been associated with a greater burden of symptomatic knee osteoarthritis. There is some evidence that patients with a very high body mass index (BMI) may have a higher risk of complications and poor outcomes following total knee replacement compared with non-obese patients or obese patients with a lower BMI. We hypothesized that increasing degrees of obesity would be associated with deteriorating outcomes for patients following total knee replacement.

METHODS

We performed a comprehensive systematic review of 4 medical databases (MEDLINE, AMED, Ovid Healthstar, and Embase) from inception to August 2016. We extracted data to determine revision risk (all-cause, septic, and aseptic) and functional outcome scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Knee Society Score, Oxford Knee Score, EuroQol-5D, and Short Form [SF]-12 Physical Component Summary) in patients with severe obesity (BMI ≥35 kg/m), morbid obesity (BMI ≥40 kg/m), and super-obesity (BMI ≥50 kg/m) in comparison with patients with a normal BMI (<25 kg/m). Meta-analysis was performed using a random effects model.

RESULTS

We screened 3,142 titles and abstracts and 454 full-text articles to identify 40 eligible studies, of which 37 were included in the meta-analysis. Compared with patients with a normal BMI, the risk ratio for an all-cause revision surgical procedure was 1.19 (95% confidence interval [CI], 1.03 to 1.37; p = 0.02) in patients with severe obesity, 1.93 (95% CI, 1.27 to 2.95; p < 0.001) in patients with morbid obesity, and 4.75 (95% CI, 2.12 to 10.66; p < 0.001) in patients with super-obesity. The risk ratio for septic revision was 1.49 (95% CI, 1.28 to 1.72; p < 0.001) in patients with severe obesity, 3.69 (95% CI, 1.90 to 7.17; p < 0.001) in patients with morbid obesity, and 4.58 (95% CI, 1.11 to 18.91; p = 0.04) in patients with super-obesity. There were no significant differences (p > 0.05) in risk of aseptic revision. Based on the Knee Society Scores reported in a single study, patients with super-obesity had outcome scores, expressed as the standardized mean difference, that were 0.52 lower (95% CI, 0.80 lower to 0.24 lower; p < 0.001) than non-obese controls; however, no difference was observed for severe or morbidly obese patients.

CONCLUSIONS

The risk of septic revision is greater in patients with severe obesity, morbid obesity, and super-obesity, with progressively higher BMI categories associated with a higher risk. However, the risk of aseptic revision was similar between all obese and non-obese patients. Functional outcome improvements are also similar, except for super-obese patients, in whom data from a single study suggested slightly lower scores. These findings may serve to better inform evidence-based clinical, research, and policy decision-making.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Early Surgical Complications of Total Hip Arthroplasty in Patients With Morbid Obesity: Propensity-Matched Cohort Study of 3683 Patients

BACKGROUND

The aim of this study is to determine whether the high risk of surgical complications within 1 year of total hip arthroplasty (THA) is due to associated comorbidities or morbid obesity alone as measured by body mass index (BMI ≥ 40 kg/m²).

METHODS

Population-based retrospective cohort study was conducted of all adults in Ontario undergoing primary THA for osteoarthritis (2012-2018). All patients were followed for 1 year. Outcomes were compared among matched groups (hypertension, diabetes, chronic obstructive pulmonary disease, frailty, congestive heart failure, coronary artery disease, asthma, and Charlson score). Primary outcome measure was major surgical complications within 1 year (composite of deep infection requiring surgery, dislocation requiring closed or open reduction, and revision surgery).

RESULTS

A total of 3683 patients with morbid obesity were matched and had a significantly greater risk of major complications within 1-year (132 [3.6%] vs 54 [1.5%]; hazard ratio [HR] 2.54, 95% confidence interval [CI]; 1.98-3.25). This included greater risk for deep infection requiring surgery (100 [2.8%] vs 26 [0.7%]; HR 3.85, 95% CI; 2.70-45.48) and revision arthroplasty (86 [2.4%] vs 34 [0.9%]; HR 2.61, 95% CI; 1.92-3.55). Operative time was also longer with a median 116 (99-138) vs 102 (87-121) minutes. There were no significant differences in hospital stay, cost of acute care episode, or medical complications.

CONCLUSION

Patients' large body habitus seems to contribute to the increased risk of surgical complications within 1-year of THA. Future research is needed to identify ways of mitigating surgical complications such as centralizing care for this complex group of patients in specialist centers.

Fate of the Morbidly Obese Patient Who Is Denied Total Joint Arthroplasty

BACKGROUND

The purpose of this study is to investigate outcomes of patients denied total hip (THA) or knee arthroplasty (TKA) due to morbid obesity.

METHODS

We performed an observational study of patients denied arthroplasty due to morbid obesity. A survey including the Harris Hip Score or pain and function components of the original Knee Society Score (KSS) was conducted with minimum 2-year follow-up. Statistical analysis was performed with parametric testing with significance at P < .05.

RESULTS

In total, 125 (4.4%) of 2819 patients were denied THA or TKA due to morbid obesity. Twenty-four (19.2%) met target weight and underwent arthroplasty at our institution. Of the remaining 101 (80.8%) patients, 33 (32.7%) agreed to participate in the survey. None received THA and 6 received TKA elsewhere above target body mass index. Harris Hip Score was significantly higher in the successful weight loss cohort at our institution (70.5 ± 13.4 vs 34.6 ± 13.1). KSS Pain (maximum score of 50) and Function (maximum score of 100) were significantly higher in the successful weight loss cohort at our institution (32.9 ± 16.5; 51.1 ± 19.5) compared to the denied nonoperative cohort (7.2 ± 11.5; 33.0 ± 23.1); however, only KSS Pain was higher when compared to the TKA elsewhere cohort (14.2 ± 18.0; 29.2 ± 38.7). KSS Pain and Function were similar for both denial cohorts regardless of undergoing arthroplasty.

CONCLUSION

Nearly 80% of patients denied never met target weight for arthroplasty. Those who met target weight prior to arthroplasty often reported better outcomes. Outcomes were similar when target weight was not met regardless of undergoing arthroplasty.

Estrogen Receptor beta (ERβ) Regulation of Lipid Homeostasis-Does Sex Matter?

In this communication, we aim to summarize the role of estrogen receptor beta (ERβ) in lipid metabolism in the main metabolic organs with a special focus on sex differences. The action of ERβ is tissue-specific and acts in a sex-dependent manner, emphasizing the necessity of developing sex- and tissue-selective targeting drugs in the future.

Greater risks of complications, infections, and revisions in the obese versus non-obese total hip arthroplasty population of 2,190,824 patients: a meta-analysis and systematic review

BACKGROUND

Obesity is an epidemic, especially in developed countries. This affects the general health of these patients, especially when they are having a major surgical procedure such as total hip arthroplasty (THA). Several articles have described the effects of obesity on THA with varying conclusions. This meta-analysis aims to compare the outcomes, complications, and peri-operative parameters of THA in the obese (BMI≥30 kg/m²) vs non-obese (BMI<30 kg/m²) population as well as a subgroup analysis of morbidly obese (BMI≥40 kg/m²) vs non-obese population.

METHODS

A multi-database search was performed according to PRISMA guidelines. Data from studies assessing the outcomes and complications of THA in the obese and non-obese population were extracted and analyzed.

RESULTS

Sixty-seven studies were included in this meta-analysis, consisting of 581,012 obese and 1,609,812 non-obese patients. Meta-analysis could not be performed on patient reported outcome measures due to heterogeneous reporting methods. Obese patients had a higher risk of all complications (OR = 1.53, 95%CI: 1.30-1.80, P < 0.001), deep infections (OR = 2.71, 95%CI: 2.08-3.53, P < 0.001), superficial infections (OR = 1.99, 95%CI: 1.55-2.55, P < 0.001), dislocations (OR = 1.72, 95%CI: 1.66-1.79, P < 0.001), reoperations (OR = 1.61, 95%CI: 1.40-1.85, P < 0.001), revisions (OR = 1.44, 95%CI: 1.32-1.57, P < 0.001), and readmissions (OR = 1.37, 95%CI: 1.15-1.63, P < 0.001). When sub-group analysis of morbidly obese (BMI≥40 kg/m²) patients was performed, the risks of all these parameters were even greater.

CONCLUSION

Obese and morbidly obese patients are at higher risks of complications post THA than non-obese patients. Surgeons should be aware of these risks in order to counsel patients and adopt prophylactic strategies to reduce these risks where applicable.

Longitudinal changes in patient-reported outcome measures following total hip arthroplasty and predictors of deterioration during follow-up

Aims

The primary aim of this study was to quantify the improvement in patient-reported outcome measures (PROMs) following total hip arthroplasty (THA), as well as the extent of any deterioration through the seven-year follow-up. The secondary aim was to identify predictors of PROM improvement and deterioration.

Patients and Methods

A total of 976 patients were enrolled into a prospective, international, multicentre study. Patients completed a battery of PROMs prior to THA, at three months post-THA, and at one, three, five, and seven-years post-THA. The Harris Hip Score (HHS), the 36-Item Short-Form Health Survey (SF-36) Physical Component Summary (PCS), the SF-36 Mental Component Summary (MCS), and the EuroQol five-dimension three-level (EQ-5D) index were the primary outcomes. Longitudinal changes in each PROM were investigated by piece-wise linear mixed effects models. Clinically significant deterioration was defined for each patient as a decrease of one half of a standard deviation (group baseline).

Results

Improvements were noted in each PROM between the preoperative and one-year visits, with one-year values exceeding age-matched population norms. Patients with difficulty in self-care experienced less improvement in HHS (odds ratio (OR) 2.2; p = 0.003). Those with anxiety/depression experienced less improvement in PCS (OR -3.3; p = 0.002) and EQ-5D (OR -0.07; p = 0.005). Between one and seven years, obesity was associated with deterioration in HHS (1.5 points/year; p = 0.006), PCS (0.8 points/year; p < 0.001), and EQ-5D (0.02 points/year; p < 0.001). Preoperative difficulty in self-care was associated with deterioration in HHS (2.2 points/year; p < 0.001). Preoperative pain from other joints was associated with deterioration in MCS (0.8 points/year; p < 0.001). All aforementioned factors were associated with clinically significant deterioration in PROMs (p < 0.035), except anxiety/depression with regard to PCS (p = 0.060).

Conclusion

The present study finds that patient factors affect the improvement and deterioration in PROMs over the medium term following THA. Special attention should be given to patients with risk factors for decreased PROMs, both preoperatively and during follow-up. Cite this article: Bone Joint J 2019;101-B:768–778.