Percent Body Fat Is More Predictive of Function After Total Joint Arthroplasty Than Body Mass Index

Association between radiographic soft-tissue thickness and increased length of stay, operative time, and infection rate after reverse shoulder arthroplasty

BACKGROUND

Reverse shoulder arthroplasty (RSA) is a widely performed surgical procedure to address various shoulder pathologies. Several studies have suggested that radiographic soft-tissue thickness may play a role in predicting complications after orthopedic surgery, but there have been limited studies determining the use of radiographic soft-tissue thickness in RSA. The purpose of this study was to evaluate whether radiographic soft-tissue thickness could predict clinical outcomes after RSA and compare the predictive capabilities against body mass index (BMI). We hypothesized that increased radiographic shoulder soft-tissue thickness would be a strong predictor of operative time, length of stay (LOS), and infection in elective RSA.

MATERIAL AND METHODS

A retrospective review of patients undergoing RSA at an academic institution was conducted. Preoperative radiographic images were evaluated including measurements of the radius from the humeral head center to the skin (HS), deltoid radius-to-humeral head radius ratio (DHR), deltoid size, and subcutaneous tissue size. Different correlation coefficients were used to analyze various types of relationships, and the strength of these associations was classified based on predefined boundaries. Subsequently, multivariable linear and logistic regressions were performed to determine whether HS, DHR, deltoid size, and subcutaneous tissue size could predict LOS, operative time, or infection while controlling for patient factors.

RESULTS

HS was the most influential factor in predicting both operative time and LOS after RSA, with strong associations indicated by standardized β coefficients of 0.234 for operative time and 0.432 for LOS. Subcutaneous tissue size, deltoid size, and DHR also showed stronger predictive values than BMI for both outcomes. In terms of prosthetic joint infection, HS, deltoid size, and DHR were significant predictors, with HS demonstrating the highest predictive power (Nagelkerke R2 = 0.44), whereas BMI did not show a statistically significant association with infection. Low event counts resulted in wide confidence intervals for odds ratios in the infection analysis.

CONCLUSION

Greater shoulder soft-tissue thickness as measured with concentric circles on radiographs is a strong predictor of operative time, LOS, and postoperative infection in elective primary RSA patients.

Association of Radiographic Soft Tissue Thickness With Revision Total Ankle Arthroplasty Following Primary Total Ankle Arthroplasty: A Minimum of 5-year Follow-up

Background

The incidence of primary total ankle arthroplasty (TAA) is rising, with a corresponding increase in revision surgeries. Despite this, research on risk factors for revision TAA following primary TAA remains limited. Radiographic soft tissue thickness has been explored as a potential predictor for outcomes in hip, knee, and shoulder arthroplasty, but its role in TAA has not been assessed. This study aimed to assess the predictive value of radiographic soft tissue thickness for identifying patients at risk of requiring revision surgery following primary TAA.

Methods

A retrospective study was conducted on 323 patients who underwent primary TAA between 2003 and 2019. Radiographic measurements of soft tissue thickness were obtained from preoperative radiographs. Two novel radiographic measures of soft tissue thickness were developed and assessed (tibial tissue thickness and talus tissue thickness). Clinical variables including age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, diabetes, smoking status, primary diagnosis, and implant type were recorded. Logistic regression analysis was used to assess the predictive value of soft tissue thickness and BMI for revision TAA.

Results

The rate of revision surgery was 4.3% (14 of 323 patients). Patients requiring revision had significantly greater tibial tissue (3.54 vs 2.48 cm; P = .02) and talus tissue (2.79 vs 2.42 cm; P = .02) thickness compared with those not requiring revision. Both the tibial tissue thickness (odds ratio 1.16 [1.12-1.20]; P < .01) and the talus tissue thickness (odds ratio: 1.10 [1.05-1.15]; P < .01) measurements were significant predictors of revision TAA in multivariable logistic regression models. However, BMI was not a significant predictor of revision TAA. The two metrics demonstrated excellent interrater reliability.

Conclusion

Greater soft tissue thickness was a better predictor of revision TAA compared with BMI. These findings suggest that radiographic soft tissue thickness may be a valuable tool for assessing the risk of the need for revision TAA following primary TAA. Further research is needed to validate and explore the potential impact on clinical practice.

Level of Evidence

Level III, comparative study.

Visceral Fat as a Risk Factor for Periprosthetic Joint Infection After Total Hip and Knee Arthroplasty

BACKGROUND

Visceral obesity, a strong indicator of chronic inflammation and impaired metabolic health, has been shown to be associated with poor postoperative outcomes and complications. This study aimed to evaluate the relationship between visceral fat area (VFA) and periprosthetic joint infection (PJI) in total joint arthroplasty (TJA) patients.

METHODS

A retrospective study of 484 patients who had undergone a total hip or knee arthroplasty was performed. All patients had a computed tomography scan of the abdomen/pelvis within two years of their TJA. Body composition data (ie, VFA, subcutaneous fat area, and skeletal muscle area) were calculated at the Lumbar-3 vertebral level via two fully automated and externally validated machine learning algorithms. A multivariable logistic model was created to determine the relationship between VFA and PJI, while accounting for other PJI risk factors. Of the 484 patients, 31 (6.4%) had a PJI complication.

RESULTS

The rate of PJI among patients with VFA in the top quartile (> 264.1 cm2) versus bottom quartile (< 82.6 cm2) was 5.6% versus 10.6% and 18.8% versus 2.7% in the total hip arthroplasty and total knee arthroplasty cohorts, respectively. In the multivariate model, total knee arthroplasty patients with a VFA in the top quartile had a 30.5 times greater risk of PJI than those in the bottom quartile of VFA (P = .0154).

CONCLUSION

VFA may have a strong association with PJI in TJA patients. Using a standardized imaging modality like computed tomography scans to calculate VFA can be a valuable tool for surgeons when assessing risk of PJI.

Super-obese patients are associated with significant infection burden after total hip arthroplasty

INTRODUCTION

Over ⅓ of the population in the United State is obese (body mass index [BMI] >30 kg/m2), with an increasing proportion being morbidly obese (BMI >40 kg/m2). As the obesity rate climbs, an increasing number have entered the super-obese category (BMI >50 kg/m2), theoretically increasing risk for complications after total hip arthroplasty (THA). This study compared complications in non-obese, obese, morbidly obese, and super-obese patients undergoing THA. We specifically assessed: (1) 1- and 2-year peri-prosthetic joint infection (PJI) rates; (2) complication rates; as well as (3) 1- and 2-year revision rates.

METHODS

A database review identified patients undergoing primary THA from 01 January 2010 to 31 December 2019. Patients were stratified based on the presence of International Classification of Diseases, 9th and 10th revision diagnosis codes of non-obese (BMI <30 kg/m2) (n = 8680), obese (BMI <40 kg/m2) (n = 12,443), morbidly obese (BMI <50 kg/m2) (n = 5250), and super-obese (BMI >50 kg/m2) (n = 814) prior to THA. Complication rates at 90 days, 1 year, and 2 years were compared across groups.

RESULTS

At all time points, super-obese patients were associated with higher rates of PJI, even when compared to morbidly obese patients. Complications such as sepsis, venous thrombo-embolism, and revision surgeries were found in higher numbers in super-obese as well as morbidly obese patients, compared to obese and non-obese patients.

CONCLUSIONS

This study provides large-scale analyses demonstrating the association between super-obese and morbidly obese patients and higher infection rates, as well as complications, following THA. Importantly, the association of PJI is highest among super-obese patients, even when compared to morbidly obese patients. Attaining a BMI <40 kg/m2 prior to surgery may be an important goal discussed with patients to lower the chance of postoperative infections.

[Nutritional, bone and body composition assessment of patients with knee and hip arthroplasty]

INTRODUCTION

malnutrition, both due to deficiency and excess of nutrients, is related to the morbidity of the surgical patient.

OBJECTIVES

to analyze the nutritional status, body composition and bone health of patients undergoing elective knee and hip arthroplasty.

METHODS

an observational cross-sectional study was carried out evaluating patients undergoing hip and knee replacement surgery from February to September 2019. The Malnutrition Universal Screening Tool (MUST), anthropometry, hand-grip dynamometry, bone densitometry, lumbar spine X-ray and bioimpedance analysis were performed.

RESULTS

eighty-six patients (61.6 % women) were evaluated, with a mean age of 69.5 ± 9.5 years. The mean body mass index (BMI) was 31.3 ± 4.5. According to MUST, 21.3 % were at risk of malnutrition; 16.9 % had decreased triceps skinfold with respect to p50 and 20 % had a pathological hand-grip dynamometry. In 91.4 %, vitamin D was < 30 pg/ml. In the bioimpedanciometry, the women presented significantly decreased muscle mass values. Age was correlated with a lower presence of fat-free mass, total and appendicular muscle mass. In those over 65 years of age, 52.6 % of men vs 14.3 % of women had a decreased muscle mass index; 58.5 % had low bone mineral density. We observed vertebral bone collapses in 13.9 %.

CONCLUSION

there is a high prevalence of obesity in patients who are candidates for arthroplasty and this does not exclude the existence of a risk of malnutrition. They may also have decreased muscle mass and strength. Nutritional education and physical exercise recommendations are essential in order to optimize nutritional status for surgery.

The use of local adiposity as a proxy for obesity in primary total hip arthroplasty: A systematic review

Introduction

Preoperative optimization of obese patients is a critical component of risk stratification in primary total hip arthroplasty (THA). Body mass index is ubiquitously utilized as a proxy for obesity due to its ease of attainment and simplistic interpretation. The use of adiposity as a proxy for obesity is an emerging concept. Local adiposity provides insight into the magnitude of peri-incisional tissue and has demonstrated an association with postoperative complications. Our objective was to review the literature to determine if local adiposity is a reliable predictor for complications following primary total hip arthroplasty.

Methods

In keeping with the PRISMA guidelines, a database search of PubMed was conducted for articles which reported on the relationship between quantified measures of adiposity at the hip and rates of complication following primary THA. Methodological quality was assessed using GRADE and risk of bias using ROBINS-I.

Results

A total of six articles (N = 2931) met the inclusion criteria. Local adiposity at the hip was measured on anteroposterior radiograph in four articles and was measured intraoperatively in two. Across four of the six articles, adiposity was significantly associated with postoperative complications including prosthesis failure and infection.

Conclusion

The use of BMI as a predictor for postoperative complication has been fraught with inconsistency. There is momentum for adiposity to be used as a proxy for obesity in preoperative THA risk stratification. The current findings demonstrated that local adiposity may be a reliable predictor for complications following primary THA.

Fat tissue is a poor predictor of 1 year outcomes after total knee arthroplasty: A secondary analysis of a randomized clinical trial

BACKGROUND AND OBJECTIVE

Obesity may increase the risk of adverse events after total knee arthroplasty (TKA). Although body mass index (BMI) is commonly used in categorizing obesity, its accuracy is limited. Body fat percentage (BFP) might indicate adiposity status and predict arthroplasty-related outcomes better than BMI. We investigated whether BFP is predictive of TKA-related outcomes.

METHODS

In this secondary analysis, BFP was measured preoperatively from 294 participants of a randomized trial that investigated the effects of tourniquet and anesthesia methods on TKA. Data concerning in-hospital assessments and events were collected. Knee range of motion (ROM) was measured, the Brief Pain Inventory-short form and Oxford Knee Score questionnaires were used to collect data on patient-reported pain and function, and the 15-dimensional health-related questionnaire was used to assess quality of life preoperatively and 3 and 12 months postoperatively. The patients reported satisfaction to TKA 3 and 12 months postoperatively. Data concerning infectious and thromboembolic events within 90 postoperative days and revision surgery, manipulation under anesthesia, and mortality within 1 year were collected. A separate post hoc analysis was performed for 399 participants to assess the effects of BMI on the respective outcomes.

RESULTS

A 1-unit increase in BFP affected the ROM by -0.37° (95% confidence interval (CI) = -0.60 to -0.13) 12 months after surgery. BFP was not significantly associated with the operation time or adverse events. However, the number of most adverse events remained too low for adjusted analysis. A 1-unit increase in BMI increased the operation time by 0.57 min (95% CI = 0.10 to 1.04) and affected the ROM by -0.47° (95% CI = -0.74 to -0.20) 12 months postoperatively. Neither BFP nor BMI was significantly associated with acute pain, pain management, length of stay, or with pain, function, quality of life, or satisfaction to TKA at 12 months after surgery.

CONCLUSIONS

BFP seems to be a poor predictor of in-hospital results and of patient-reported outcomes 1 year after TKA.

TWITTER HANDLE

In this secondary analysis of a randomized trial, body fat percentage was poorly predictive of clinical outcomes during hospital stay and of patient-reported outcomes 1 year after TKA.

Whole-body phase angle correlates with pre-operative markers in total joint arthroplasty

Background

Bioimpedance derived whole body phase angle (ϕ), a measure of cellular integrity, has been identified as an independent marker of morbidity and mortality in many medical and surgical specialties. While similar measures of water homeostasis like extracellular edema (EE) have been associated with pre-operative risk, ϕ has not been studied in orthopaedics, despite potential to serve as a pre-operative marker. This study aims to identify relationships between ϕ, EE, and body composition metrics, laboratory values, patient reported outcomes, and comorbidities.

Methods

Multi-frequency bioimpedance analysis (BIA) records, laboratory values, and patient reported outcomes of adult patients presenting to an academic arthroplasty clinic were retrospectively reviewed. Correlation coefficients between ϕ, EE, and reviewed information were conducted.

Results

ϕ was significantly correlated (p<0.001) most positively with measures of lean tissue such as skeletal muscle mass (r=0.48), appendicular skeletal muscle index (r=0.39), lean body mass (r=0.43), and dry lean mass (r=0.47), while it held negative correlations (p<0.001) with age (r= -0.55), and body fat mass (r= -0.11). ϕ was not correlated with body mass index (BMI, p = 0.204). In contrast, EE demonstrated its strongest positive correlations (p<0.001) with body fat mass (r=0.32), age (r=0.50), and BMI (r=0.26), and its strongest negative correlations (p<0.001) with serum albumin (r= -0.37) and total protein (r= -0.23).

Conclusions

Based on their associations with markers of health and fitness, BIA determined ϕ and EE demonstrate relationships to markers currently implemented in orthopaedic practice. This likely indicates that ϕ has potential as a comprehensive surrogate for several commonly used markers to quantify pre-operative risk. In the future, ϕ may aid in developing risk-stratifications for intervention and prevention of complications.

Association Between Nonsurgical Weight Loss From Body Mass Index >40 to Body Mass Index <40 and Complications and Readmissions Following Total Hip Arthroplasty

BACKGROUND

Elevated body mass index (BMI) is a risk factor for adverse outcomes following total hip arthroplasty (THA). It is unknown if preoperative weight loss to a BMI <40 kg/m² is associated with reduced risk of adverse outcomes.

METHODS

We retrospectively reviewed elective, primary THA performed at an academic center from 2015 to 2019. Patients were split into groups based on their BMI trajectory prior to THA: BMI consistently <40 ("BMI <40"); BMI >40 at the time of surgery ("BMI >40"); and BMI >40 within 2 years preoperatively, but <40 at the time of surgery ("Weight Loss"). Length of stay (LOS), 30-day readmissions, and complications as defined by Centers for Medicare and Medicaid Services were compared between groups using parsimonious regression models and Fisher's exact testing. Adjusted analyses controlled for sex, age, and American Society of Anesthesiologists class.

RESULTS

In total, 1589 patients were included (BMI <40: 1387, BMI >40: 96, Weight Loss: 106). The rate of complications in each group was 3.5%, 6.3%, and 8.5% and the rate of 30-day readmissions was 3.0%, 4.2%, and 7.5%, respectively. Compared to the BMI <40 group, the weight loss group had a significantly higher risk of 30-day readmission (odds ratio [OR] 2.70, 95% confidence interval [CI] 1.19-6.17, P = .02), higher risk of any complication (OR 2.47, 95% CI 1.09-5.59, P = .03), higher risk of mechanical complications (OR 3.07, 95% CI 1.14-8.25, P = .03), and longer median LOS (16% increase, P = .002). The BMI >40 group had increased median LOS (10% increase, P = .03), but no difference in readmission or complications (P > .05) compared to BMI <40.

CONCLUSION

Weight loss from BMI >40 to BMI <40 prior to THA was associated with increased risk of readmission and complications compared to BMI <40, whereas BMI >40 was not.

LEVEL OF EVIDENCE

Level III - Retrospective Cohort Study.

Thickness of the Subcutaneous Fat as a Risk Factor for Surgical Site Infection Following Fragility Hip Fracture Surgery

INTRODUCTION

Surgical site infection (SSI) following fragility hip fracture (FHF) surgery is associated with increased morbidity and mortality.

SIGNIFICANCE

Prediction of patients at risk for SSI is fundamental. We aimed to determine whether subcutaneous radiographic fat measurement (SRM) is associated with increased SSI risk.

METHODS

A retrospective case-control comparison of SRMs at 3 locations around the hip. Patients diagnosed with SSI in the first post-operative year were matched with age, gender, surgical year, Charlsons' co-morbidity index score, and surgical type controls, not diagnosed with SSI, at a 1:2 ratio. Measurements included the distance between (1) the sourcil to skin surface (SS), (2) the tip of the greater trochanter to skin surface (TGTS), and (3) the most prominent lateral aspect of the greater trochanter to skin surface.

RESULTS

1430 patients were operated during the study period, of whom 45 patients presented with a diagnosis of SSI and compared to 90 controls. Infections occurred 27.4 ( ± 24.8) days following surgery. SRM significantly differed between groups, and all were higher in the study group; SS, 86.8 ± 25.5 cm vs 74.2 ± 15.3 cm; TGTS, 59.8 ± 26.3 cm vs 47.0 ± 15.8 cm; and LGTS, 45.4 ± 25.1 cm vs 33.2 ± 15.1 cm (P = .003, .004, and .004, respectively). Intraclass correlation coefficients (intra-rater) were high for all measurements (.999 for all). Intraclass correlation coefficients (inter-rater) for SS, TGTS and LGTS were high, .749 (.663.815), .792 (.719.847) and .817 (.751.866), respectively.

CONCLUSIONS

SRMs were found to be a valid and reproducible tool for predicting high risk of SSI in geriatric patients sustaining FHFs.

LEVEL OF EVIDENCE

III.

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.

Body Mass Index, American Society of Anesthesiologists Score, and Elixhauser Comorbidity Index Predict Cost and Delay of Care During Total Knee Arthroplasty

BACKGROUND

Body mass index (BMI), American Society of Anesthesiologists (ASA) score, and Elixhauser Comorbidity Index are measures that are utilized to predict perioperative outcomes, though little is known about their comparative predictive effects. We analyzed the effects of these indices on costs, operating room (OR) time, and length of stay (LOS) with the hypothesis that they would have a differential influence on each outcome variable.

METHODS

A retrospective review of the institutional database was completed on primary TKA patients from 2015 to 2018. Univariable and multivariable models were constructed to evaluate the strength of BMI, ASA, and Elixhauser comorbidities for predicting changes to total hospital and surgical costs, OR time, and LOS.

RESULTS

In total, 1313 patients were included. ASA score was independently predictive of all outcome variables (OR time, LOS, total hospital and surgical costs). BMI, however, was associated with intraoperative resource utilization through time and cost, but only remained predictive of OR time in an adjusted model. Total Elixhauser comorbidities were independently predictive of LOS and total hospital cost incurred outside of the operative theater, though they were not predictive of intraoperative resource consumption.

CONCLUSION

Although ASA, BMI, and Elixhauser comorbidities have the potential to impact outcomes and cost, there are important differences in their predictive nature. Although BMI is independently predictive of intraoperative resource utilization, other measures like Elixhauser and ASA score were more indicative of cost outside of the OR and LOS. These data highlight the differing impact of BMI, ASA, and patient comorbidities in impacting cost and time consumption throughout perioperative care.

Predictors of Readmission and Prolonged Length of Stay After Cervical Disc Arthroplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of the study was to assess which factors increase risk of readmission within 30 days of surgery or prolonged length of stay (LOS) (≥2 days) after cervical disc arthroplasty (CDA).

SUMMARY OF BACKGROUND DATA

Several studies have shown noninferiority at mid- and long-term outcomes after cervical disc arthroplasty (CDA) compared to anterior cervical discectomy and fusion ACDF, but few have evaluated short-term outcomes regarding risk of readmission or prolonged LOS after surgery.

METHODS

Demographics, comorbidities, operative details, postoperative complications, and perioperative outcomes were collected for patients undergoing single level CDA in the National Surgical Quality Improvement Program (NSQIP) database. Patients with prolonged LOS, defined as >2 days, and readmission within 30 days following CDA were identified. Univariable and multivariable logistic regression models were used to identify risk factors for prolonged LOS and readmission.

RESULTS

A total of 3221 patients underwent single level CDA. Average age was 45.6 years (range 19-82) and 53% of patients were male. A total of 472 (14.7%) experienced a prolonged LOS and 36 (1.1%) patients were readmitted within 30 days following surgery. Predictors of readmission were postoperative superficial wound infection (odds ratio [OR] = 73.83, P < 0.001), American Society of Anesthesiologists (ASA) classification (OR = 1.98, P = 0.048), and body mass index (BMI) (OR = 1.06, P = 0.02). Female sex (OR = 1.76, P < 0.001), diabetes (OR = 1.50, P = 0.024), postoperative wound dehiscence (OR = 13.11, P = 0.042), ASA class (OR = 1.43, P < 0.01), and operative time (OR = 1.01, P < 0.001) were significantly associated with prolonged LOS.

CONCLUSION

From a nationwide database analysis of 3221 patients, wound complications are predictors of both prolonged LOS and readmission. Patient comorbidities, including diabetes, higher ASA classification, female sex, and higher BMI also increased risk of prolonged LOS or readmission.Level of Evidence: 3.

Greater Knee Soft Tissue Thickness Predisposes Patients to Subsequent Periprosthetic Joint Infection After Total Knee Arthroplasty

BACKGROUND

Although obesity is a risk factor for periprosthetic joint infection (PJI) after total knee arthroplasty (TKA), the role of soft tissue thickness (STT) at the surgical site has not been well studied. This study examined if increased STT in the medial and anterior aspects of the knee are independent risk factors for PJI.

METHODS

A retrospective study was conducted on 206 patients who underwent 2-stage exchange arthroplasty for PJI from 2000 to 2015. They were matched 1:3 to a control group of primary, noninfected TKA patients with minimum 2 years infection-free survival by age, gender, age-adjusted Charlson Comorbidity Index, date of surgery, and body mass index (BMI). Two blinded orthopedic surgeons measured the medial STT from the medial aspect of the knee at the level of the joint line on an anteroposterior radiograph, and anterior STT 8 cm above the joint line on a lateral radiograph from the skin to the quadriceps tendon.

RESULTS

Increased STT was significantly associated with a higher risk for PJI. The mean anterior STT was 29.74 ± 13.76 mm in the PJI group and 24.88 ± 9.76 mm in the control group. The mean medial STT was 42.42 ± 14.66 mm for PJI and 37.27 ± 12.51 mm for control. Both STT measurements were significantly higher in PJI cases with BMI <30 kg/m² vs control patients with BMI <30 kg/m².

CONCLUSION

Anterior and medial knee STT was an independent risk factor for PJI after primary TKA and represents a simple radiographic method to assess postoperative infection risk. Excess adipose tissue around the surgical site can predispose patients to PJI after TKA regardless of BMI.

Effect of morbid obesity on patient-reported outcomes in total joint arthroplasty: a minimum of 1-year follow-up

The objective of this study is to explore the effect of morbid obesity on patient-reported outcomes in primary total joint arthroplasty. We retrospectively reviewed 755 primary total joint arthroplasty cases with a minimum of 1-year follow-up. Two groups were compared: (1) patients with BMI < 40 and (2) those with BMI ≥ 40. The primary outcome was the difference in Short Form-12 physical component summary, Short Form-12 mental component summary, Western Ontario and McMaster Universities Osteoarthritis Index, and patient satisfaction. Multivariate analyses were performed to control for potential confounding factors. 37 patients (5%) were morbidly obese. Morbidly obese patients undergoing total knee arthroplasty had significantly lower net gains in their Short Form-12 physical component summary (P = .008), Short Form-12 mental component summary (P = .049), and Western Ontario and McMaster Universities Osteoarthritis Index (P = .009) in the first 6 months only. For total hip arthroplasty, morbid obesity did not affect any of the outcomes measured (P > .05). There was also no difference in patient satisfaction rates between the two groups (P = .401 and .143 for total hip arthroplasty and total knee arthroplasty, respectively). The impact of morbid obesity on patient-reported outcomes appears to be limited to total knee arthroplasty only in the initial 6 months after surgery.

Influence of body mass index on health-related quality of life after surgical treatment of intra-articular distal radius fractures. A retrospective 7-year follow-up study

Morbid obesity is associated with reduced health-related quality of life (HRQOL), increased morbidity and mortality. Little is known about the correlation between obesity and complex distal radius fractures (DRF). The purpose of this study was to examine the effect of being overweight on postoperative HRQOL after surgically treated intra-articular DRF. Fifty-three patients were included in this retrospective study with 7 years' mean follow-up (mean 7.2±0.4, range 6.4-7.9 years) after volar plating of an intra-articular DRF (AO-type C). All patients were categorized by their body mass index (BMI) into two study groups: group 1 (normal weight) with a BMI<25 (n=24); group 2 (obese) with a BMI≥25 (n=29). HRQOL and functional outcomes were assessed through range of motion (ROM) and four different scores - the 36-item short form health survey (SF-36), the disability of arm and shoulder score (DASH), the Gartland and Werley score and the Castaing score - along with X-rays to measure volar tilt, radial inclination, radial length and articular congruity. All HRQOL assessments and clinical outcomes were correlated to BMI by comparing group 1 versus group 2. There was no difference in terms of postoperative ROM. The group of normal weight patients achieved slightly better but non-significant results for the Gartland and Werley score. No differences were seen in the DASH score or SF-36. There were also no differences regarding the Castaing score. Overall, normal and obese patients had no significant differences their HRQOL and functionality after volar plating of DRF.

External Validity of a New Prediction Model for Patient Satisfaction After Total Knee Arthroplasty

BACKGROUND

The ability to identify patients at risk of dissatisfaction after total knee arthroplasty (TKA) remains elusive. This study's purpose was to determine the external validity of a recently published prediction model for patient satisfaction (PMPS) with the hypothesis that it would achieve similar predictive success in our study sample.

METHODS

A 10-question PMPS statistically derived from 5 patient-reported outcome questionnaires was tested for external validity in this prospective cohort investigation. The PMPS incorporates gender, age, stiffness, noise, and pain catastrophizing, with a score of 20 or greater predictive of satisfaction. As in the original study, to determine satisfaction the 2011 Knee Society Score (KSS) satisfaction subscale was collected at 3 months postoperatively. Two hundred seventy-four patients were administered the PMPS preoperatively, and 145 patients completed the KSS at 3 months postoperatively (53.0% response rate; 59% female; age, 64.9; body mass index, 32.5). A Bland-Altman analysis to assess agreement was performed.

RESULTS

One hundred thirty-three patients (91.7%) were satisfied and 12 (8.3%) were dissatisfied based on their postoperative KSS. The mean difference between the PMPS and KSS was 3.6 ± 8, but with a 95% prediction interval of -15.3 to 22.1 signifying almost no correlation. The PMPS did not predict any of the 12 dissatisfied patients postoperatively, and falsely predicted 5 patients to be dissatisfied of which 4 actually had a maximum postoperative KSS of 40.

CONCLUSION

A previously published, internally validated 10-question PMPS was unable to predict satisfaction after TKA in our external study sample. This study emphasizes the difficulty of developing a simple, but robust questionnaire that consistently predicts patient satisfaction after TKA.

The Effect of Body Mass Index on 30-day Complications After Revision Total Hip and Knee Arthroplasty

BACKGROUND

We aimed to explore the effect of body mass index (BMI) on 30-day complications after aseptic revision total knee arthroplasty (rTKA) and aseptic revision total hip arthroplasty (rTHA), considering BMI as both a categorical and continuous variable.

METHODS

A total of 18,866 patients (9093 rTHA and 9773 rTKA) patients were included for analysis using the American College of Surgeons National Surgical Quality Improvement Project database. Thirty-day rates of readmissions, reoperations, and major and minor complications were compared between different weight categories (overweight: BMI >25 and ≤30 kg/m²; obese: BMI >30 and ≤40 kg/m²; morbidly obese: BMI >40 kg/m²) and the normal weight category (BMI >18.5 and ≤25 kg/m²) using multivariate regression models. Spline regression models were created to study BMI as a continuous variable.

RESULTS

Both readmission rates and reoperation rates increased for rTKA as BMI increased (P < .005). There was a linear relationship between BMI and readmission rates for rTKA. Morbid obesity was associated with an increased reoperation rate for rTHA on univariate analysis (P = .022); however, multivariate analysis showed no statistically significant increase in readmission or reoperation rates as BMI increased for rTHA.

CONCLUSIONS

The relationship between BMI and complications after revision total joint arthroplasty is a J-shaped curve with the lowest rates of complications occurring around a BMI of 30 kg/m². The relationship between BMI and perioperative complications is stronger for revision TKA as opposed to revision THA.

Modifiable and Nonmodifiable Predictive Factors Associated with the Outcomes of Total Knee Arthroplasty

Total knee arthroplasty (TKA) is a valuable treatment option for advanced osteoarthritis in patients unresponsive to conservative treatments. Despite overall satisfactory results, the rate of unsatisfied patients after TKA remains high, ranging from 5 to 40%. Different modifiable and nonmodifiable prognostic factors associated with TKA outcomes have been described. The correction, whenever possible, of modifiable factors is fundamental in preoperative patients' optimization protocols. Nonmodifiable factors can help in predicting the outcomes and creating the right expectations in the patients undergoing TKA. The goal of this review is to summarize the modifiable and nonmodifiable prognostic factors associated with TKA outcomes.

Prospective Study of Central versus Peripheral Obesity in Total Knee Arthroplasty

PURPOSE

Body mass index (BMI) is often used to predict surgical difficulty in patients receiving total knee arthroplasty (TKA); however, BMI neglects variation in the central versus peripheral distribution of adipose tissue. We sought to examine whether anthropometric factors, rather than BMI alone, may serve as a more effective indication of surgical difficulty in TKA.

MATERIALS AND METHODS

We prospectively enrolled 67 patients undergoing primary TKA. Correlation coefficients were used to evaluate the associations of tourniquet time, a surrogate of surgical difficulty, with BMI, pre- and intraoperative anthropometric measurements, and radiographic knee alignment. Similarly, Knee Injury and Osteoarthritis Outcome Score (KOOS) was compared to BMI.

RESULTS

Tourniquet time was significantly associated with preoperative inferior knee circumference (p=0.025) and ankle circumference (p=0.003) as well as the intraoperative depth of incision at the quadriceps (p=0.014). BMI was not significantly associated with tourniquet time or any of the radiographic parameters or KOOS scores.

CONCLUSIONS

Inferior knee circumference, ankle circumference, and depth of incision at the quadriceps (measures of peripheral obesity) are likely better predictors of surgical difficulty than BMI. Further study of alternative surgical indicators should investigate patients that may be deterred from TKA for high BMI, despite relatively low peripheral obesity.

Treatment satisfaction with pharmaceutical interventions in Japanese adults with osteoarthritis and chronic knee pain: an analysis of a web-based survey

Purpose

Patient satisfaction is an important outcome in successful osteoarthritis (OA) treatment. The aim of this study was to evaluate treatment satisfaction for medication (TSM) in people with knee OA (KOA), identify the factors predictive of treatment satisfaction, and describe the burden of illness.

Patients and methods

This cross-sectional, patient-reported study used an Internet-based survey and analyzed responses of respondents with KOA (N=400) on characteristics including pain sites and levels (including pain ratings using the Numerical Rating Scale and Short-Form McGill Pain Questionnaire), treatment satisfaction (Global, Effectiveness, and Convenience scores) based on the Treatment Satisfaction Questionnaire for Medication (TSQM-9), and quality of life (QoL; based on the Arthritis Impact Measurement Scale 2-Short Form). Respondents with only KOA (n=237) were compared with those having KOA and additional painful sites (KOA+; n=163). Factors predicting TSM were identified using multivariable linear regression analyses.

Results

Respondents with KOA were more likely to report intermittent pain for 3 months or more compared with those with KOA+ (58.6% vs 48.5%, respectively; P=0.044), while those with KOA+ were more likely to report consistent pain for 3 months or more (P=0.022). Respondents with KOA+ also had more difficulty due to their knee pain while sleeping (P=0.022) and resting (P=0.015). Reported TSM did not differ significantly across KOA vs KOA+ groups, with both groups reporting low satisfaction; all domains of QoL were worse for those with KOA+. Knee pain reduction by medication predicted higher satisfaction across domains, while lower pre-medication pain and post-medication pain matching expectations predicted higher TSQM-9 Global and Effectiveness scores.

Conclusion

Medication treatment satisfaction rates were low among Japanese respondents with KOA. Given that lower pain, greater pain reduction post-medication, and meeting pain management expectations were predictive of higher satisfaction, treatment strategies that can better address pain may prove beneficial for overall patient satisfaction.

Shoulder Arthroplasty Outcomes in Patients With Multiple Reported Drug Allergies: Does Number of Drug Allergies Have an Effect on Outcome?

Background:

The presence of multiple allergies has been correlated with worse outcomes for patients undergoing hip and knee arthroplasty, but the effect of allergies has not yet been elucidated with respect to shoulder arthroplasty.

Purpose/Hypothesis:

The purpose of this study is to identify any discrepancies in shoulder arthroplasty outcomes with respect to reported drug allergies. We hypothesized that patients with multiple drug allergies would have inferior outcomes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included in the analysis were a single surgeon’s cases between 2009 and 2014 of primary total shoulder arthroplasty with a minimum of 180 days of follow-up. Cases with fracture as the indication were excluded. Preoperative and postoperative metrics included visual analog scale (VAS) for pain, forward flexion range of motion, and Simple Shoulder Test (SST) results, and postoperative patient satisfaction scores were also collected. Chi-square and 1-way analysis of variance with Tukey post hoc analyses were performed when appropriate.

Results:

A total of 98 patients were included (no allergies, n = 51; single allergy, n = 21; multiple allergies, n = 26). The proportion of females was greater with increasing number of allergies (no allergies, 31%; single allergies, 47%; multiple allergies, 88%; Pearson χ² = 22.5; P < .0001). Both preoperatively and postoperatively, no difference was found between cohorts with respect to SST score, VAS score, or forward flexion. There was also no difference in postoperative satisfaction between cohorts. No difference between cohorts was identified when comparing the pre- to postoperative change in SST scores, VAS scores, or forward flexion.

Conclusion:

The presence of single or multiple allergies is not correlated with worse outcomes after primary anatomic total shoulder arthroplasty.