Obesity, knee osteoarthritis and knee arthroplasty: a review

Super-Obesity is Associated With an Increased Risk of Complications Following Primary Total Knee Arthroplasty

BACKGROUND

Obesity, defined as a body mass index (BMI) ≥ 30, is an ever-growing epidemic, with > 35% of adults in the United States currently classified as obese. Super-obese individuals, defined as those who have a BMI ≥ 50, are the fastest-growing portion of this group. This study sought to quantify the infection risk as well as the incidence of surgical, medical, and thromboembolic complications among super-obese patients undergoing total knee arthroplasty (TKA).

METHODS

An all-payer claims database was used to identify patients who underwent elective, primary TKA between 2016 and 2021. Patients who had a BMI ≥ 50 were compared to those who had a normal BMI of 18 to 25. Demographics and the incidence of 90-days postoperative complications were compared between the 2 groups. Univariate analysis and multivariable regression were used to assess differences between groups.

RESULTS

In total, 3,376 super-obese TKA patients were identified and compared to 17,659 patients who had a normal BMI. Multivariable analysis indicated that the super-obese cohort was at an increased postoperative risk of periprosthetic joint infection (adjusted odds ratio [aOR] 3.7, 95% confidence interval [CI]: 2.1 to 6.4, P < .001), pulmonary embolism (aOR 2.2, 95%-CI: 1.0 to 5.0, P = .047), acute respiratory failure (aOR 4.1, 95%-CI: 2.7 to 6.1, P < .001), myocardial infarction (aOR 2.5, 95%-CI: 1.1 to 5.8, P = .026), wound dehiscence (aOR 2.3, 95%-CI: 1.4 to 3.8, P = .001), and acute renal failure (aOR 3.2, 95%-CI: 2.4 to 4.2, P < .001) relative to patients who have normal BMI.

CONCLUSIONS

Super-obese TKA patients are at an elevated risk of postoperative infectious, surgical, medical, and thromboembolic complications. As such, risk stratification, as well as appropriate medical management and optimization, is of utmost importance for this high-risk group.

Glucagon-Like Peptide Receptor-1 Agonists Used for Medically-Supervised Weight Loss in Patients With Hip and Knee Osteoarthritis: Critical Considerations for the Arthroplasty Surgeon

Patients with morbid obesity and concomitant hip or knee osteoarthritis represent a challenging patient demographic to treat as these patients often present earlier in life, have more severe symptoms, and have worse surgical outcomes following total hip and total knee arthroplasty. Previously, bariatric and metabolic surgeries represented one of the few weight loss interventions that morbidly obese patients could undergo prior to total joint arthroplasty. However, data regarding the reduction in complications with preoperative bariatric surgery remain mixed. Glucagon-like peptide receptor-1 (GLP-1) agonists have emerged as an effective treatment option for obesity in patients with and without diabetes mellitus. Furthermore, recent data suggest these medications may serve as potential anti-inflammatory and disease-modifying agents for numerous chronic conditions, including osteoarthritis. This review will discuss the GLP-1 agonists and GLP-1/glucose-dependent insulinotropic polypeptide dual agonists currently available, along with GLP-1/glucose-dependent insulinotropic polypeptide/glucagon triple agonists presently being developed to address the obesity epidemic. Furthermore, this review will address the potential problem of GLP-1-related delayed gastric emptying and its impact on the timing of elective total joint arthroplasty. The review aims to provide arthroplasty surgeons with a primer for implementing this class of medication in their current and future practice, including perioperative instructions and perioperative safety considerations when treating patients taking these medications.

Differences Between Patients With Diabetes Mellitus and Obese Patients in Occurrence of Peri-Prosthetic Joint Infection: A Systemic Review and Meta-Analysis

Background: To understand the differences between patients with diabetes mellitus and obese patients with respect to the occurrence of peri-prosthetic joint infection (PJI) after lower-extremity joint arthroplasty as well as to identify differences in PJI occurrence at different time periods. Patients and Methods: The Cochrane Library, CINAHL, MEDLINE, and PubMed were searched for literature published between January 2000 and July 2022. Our targets were studies involving patients with PJI who had already been diagnosed as having diabetes mellitus or being obese before receiving lower-extremity joint arthroplasty. Analysis was performed using Comprehensive Meta-Analysis Software (CMA) Version 3 (Biostat, Inc., Englewood, NJ, USA). Results: A total of 53,522 patients with diabetes mellitus and 360,018 obese patients were included. The forest plot for patients with and without diabetes mellitus indicated that patients with diabetes mellitus were more likely to contract PJIs than were patients without diabetes mellitus (odds ratio, 1.84; 95% confidence interval [CI], 1.56-2.16) and that no differences existed among early, delayed, and late PJI occurrence in patients with diabetes mellitus. The forest plot for obese and non-obese patients indicated that obese patients were more likely to contract PJIs than were non-obese patients (odds ratio, 1.86; 95% CI, 1.53-2.14) and that among obese patients, early PJI occurrence was higher than was late PJI occurrence. In addition, the mixed model indicated that obese patients were more likely to develop early PJIs than were patients with diabetes mellitus. Conclusions: Patients with diabetes mellitus and obese patients were more likely to develop PJIs than were patients without diabetes mellitus and non-obese patients, and that obese patients were more likely to develop early PJIs than late PJIs. Also, obese patients were more likely to develop early PJIs than patients with diabetes mellitus.

[Impact of surgical treatment of morbid obesity on joint diseases]

The prevalence of obesity in the modern world is increasing. Obesity is an independent risk factor for some rheumatic diseases and also worsens their course. The presence of chronic joint disease can make it difficult for obesity to reduce activity, creating a vicious circle where joint pain makes exercise difficult and being overweight exacerbates joint pain. At the same time, there is a conditionally radical method of treating obesity - bariatric surgery (BS), which is currently used when conservative methods are ineffective. The purpose of this review is to analyze the data presented in the world literature on the impact of BS on the course of the most common rheumatic diseases. The available data show the possibility of a positive effect of BS not only on weight loss, but also on the course of a number of rheumatic diseases.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

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

The impact of body mass index on the accuracy of the physical examination of the knee

PURPOSE

Obesity is a worldwide pandemic; however, no adaptations were made to the physical examination of obese patient's knees. The accuracy of the physical examination is critical for correct assessment and selection of treatment. We aimed to assess whether body mass index (BMI) affects the sensitivity and specificity of common provocative knee tests.

METHODS

We studied 210 patients who underwent knee arthroscopy to treat anterior cruciate ligament (ACL) and meniscal pathologies. BMI and the knee's physical examination were documented pre-operatively. Sensitivity, specificity, and accuracy of ACL and meniscal provocative tests in relation to BMI were evaluated using arthroscopy as a gold standard.

RESULTS

The Anterior Drawer, Lachman, and Pivot-Shift tests for ACL tears were significantly less accurate and sensitive, yet more specific, in obese patients when compared to normal and overweight patients. The McMurray, Apley Grind, and Thessaly tests for medial meniscus tears showed greater sensitivity, but lower specificity, in patients with increased BMI. Above normal BMIs, independently of age and gender, were significantly associated with higher odds for positive ACL tests.

CONCLUSION

Tests for ACL tears are less sensitive in obese patients and alternatives to the classic tests should be considered. Medial meniscus tests tend to be more sensitive and less specific in patients with greater BMIs. Their results should be carefully interpreted due to possible false positives. The physician should take into consideration the impact of patient BMI on the accuracy of their physical examination of the knee to optimize treatment decision-making.

Association of Weight Change and Physical Activity with Knee Pain and Health-Related Quality of Life in East Asian Women Aged 50 Years and Older with Knee Osteoarthritis: A Population-Based Study

bjectives: This study aimed to investigate the association of self-reported weight change and physical activity with the level of knee pain and health-related quality of life in East Asian women with knee osteoarthritis using population-based data.Methods: A total of 564 women (mean age, 68.2 years, standard deviation, 8.9 years) aged 50 years or older with knee osteoarthritis (Kellgren-Lawrence (K-L) grade ≥ 2) were included in the data analyses from the fifth Korea National Health and Nutrition Examination Survey. Data regarding the radiographic grade, self-reported weight change during the past year, physical activity, level of knee pain, and health-related quality of life (EuroQOL five- dimension (EQ-5D) index) were collected. Multiple regression analysis was performed to identify factors significantly associated with the level of knee pain and health-related quality of life in subgroups according to the body mass index (BMI) range (≤ 22.5, between 22.6 and 27.5, and > 27.5 kg/m ² ).Results: In the whole group, the level of knee pain was significantly associated with K-L grade (P < 0.001), and EQ-5D was negatively associated with age (P < 0.001), the level of knee pain (P < 0.001), and weekly hours of vigorous-intensity activity (P = 0.026). In the subgroup analysis, weight gain showed significant association with the level of knee pain only in women with 22.5 kg/m² < BMI ≤ 27.5 kg/m² (P = 0.006). Weight gain showed significant association with EQ-5D in women with BMI ≤ 22.5 kg/m²(P = 0.047) whereas weekly hours of moderate-intensity activity was negatively associated with EQ-5D in women with BMI > 27.5 kg/m² .Conclusions: The association of weight change and physical activity with knee pain and health-related quality of life might be different according to BMI ranges. Well-designed interventions to improve both knee pain and health-related quality of life need to be investigated in future studies that would strictly control physical activity, diet, and weight changes.

Effects of Diet Control and Telemedicine-Based Resistance Exercise Intervention on Patients with Obesity and Knee Osteoarthritis: A Randomized Control Trial

This study investigated the effects of home-based nutritional and telemedicine-based resistance exercise interventions on improving body composition, blood biochemistry, and lower-limb functional performance. In total, 66 obese patients with mild-to-moderate knee osteoarthritis were randomly divided into a diet control group (D), elastic band resistance exercise group (E), and diet control plus elastic band exercise group (D + E). Each group was supervised by a clinical dietitian and follow-up was conducted via telephone calls or a communication application to track the participants’ progress. After 12 weeks of intervention, the D (p < 0.001) and D + E (p < 0.001) groups achieved significant weight loss. The D + E group exhibited a significant reduction in body fat relative to the D (p = 0.019) and E (p = 0.012) groups. Compared with the D (p = 0.002) and E (p = 0.019) groups, the D + E group achieved significant improvements in the timed up-and-go test and Western Ontario and McMaster Universities Osteoarthritis total scale. The D + E group experienced significant improvements in total cholesterol (p = 0.001), low-density lipoprotein cholesterol (p = 0.01), and triglyceride levels (p = 0.007) relative to other groups. In conclusion, individual diet control intervention combined with telemedicine-based resistance exercise intervention significantly improved the body composition, blood biochemistry, and lower-limb functional performance of the investigated population with comorbid conditions.

The gut microbiome as non-invasive biomarkers for identifying overweight people at risk for osteoarthritis

OBJECTIVE

To evaluate the potential for identifying overweight people at risk for osteoarthritis from a gut microbiome biomarker.

BACKGROUND

Osteoarthritis (OA) is the most common form of arthritis, affecting millions of people worldwide. Being overweight increases the load placed on the joints such as the knee, which increases stress and could hasten the breakdown of cartilage. Identifying overweight people at risk for osteoarthritis remains a challenge. However, emerging evidence indicates that microbial dysbiosis in the human gut might play an important role in many inflammatory diseases. Considering the role of inflammation in OA development, analysis of the gut microbiome might be a potential non-invasive tool for overweight individuals to evaluate their risk for OA.

RESULTS

In this prospective study, we collected 182 stool samples from overweight OA patients (n = 86) and overweight normal people (n = 96) (25 kg/m²<BMI<30 kg/m²). 16S ribosomal RNA gene sequencing for V3 and V4 regions on the Illumina MiSeq platform was used to identify bacteria at different levels and it showed that both the diversity and richness of the gut microbiome decreased in overweight OA patients. Correspondingly, 9 phyla and 87 genera had significantly differences between overweight OA patients and overweight normal people. Finally, we identified 7 optimal microbial biomarkers in genus levels as a panel, including Gemmiger, Klebsiella, Akkermansia, Bacteroides, Prevotella, Alistipes and Parabacteroides, to build the random forest model, and achieved a 83.36% area under the curve (AUC) of receiver operating characteristic (ROC).

CONCLUSION

We present the first 16S rRNA gene sequencing profiling study of stool microbiomes in overweight people to discover and validate microbial biomarkers indicating risk for OA. Our study successfully established a 7 biomarkers prediction panel, moving towards affordable non-invasive early diagnostic biomarkers for OA in stool samples from overweight individuals.

Does weight loss reduce the incidence of total knee and hip replacement for osteoarthritis?-A prospective cohort study among middle-aged and older adults with overweight or obesity

Objective

This study aims to investigate the association between weight change and total knee or hip replacement (TKR or THR) for OA among middle-aged and older adults with overweight or obesity.

Method

Weight data were collected in 2006–2009 and in 2010 from the 45 and Up Study—a population-based cohort aged ≥45 years in New South Wales, Australia. Participants were included if they had a baseline body mass index (BMI) ≥ 25 kg/m² and no history of TKR or THR. Weight change was categorised into four groups: >7.5% loss; >5–7.5% loss; stable (≤5% change) and >5% gain. Hospital admission data were linked to identify TKR and THR for OA, and multivariable Cox regression was used to assess risk of TKR and THR.

Results

Of 23,916 participants, 2139 lost >7.5% weight, 1655 lost 5–7.5% weight, and 4430 gained >5% weight. Over 5.2 years, 1009 (4.2%) underwent TKR and 483 (2.0%) THR. Compared to weight-stable, weight loss of >7.5% was associated with reduced risk of TKR after adjusting for age, sex, BMI, socioeconomic and lifestyle factors (hazard ratio 0.69, 95%CI 0.54–0.87), but had no association with THR. Weight loss of 5–7.5% was not associated with altered risk of either TKR or THR. Weight gain was associated with increased risk of THR after adjusting for confounders, but not TKR.

Conclusion

This study suggests that a weight loss target >7.5% is required to reduce the risk of TKR in adults with overweight or obesity. Weight gain should be avoided as it increases the risk of THR.

Nationwide Cross-Sectional Study of the Association between Knee Pain and Weight Change: Analysis of the Korea National Health and Nutrition Examination Survey (KNHANES 2013-2015)

The knee is a hinge joint that provides stability and control, which are essential in daily life. Obesity is a major cause of knee pain and its incidence continues to increase worldwide. In this study, we analyzed Korea National Health and Nutrition Examination Survey data on the general population, and showed an association between weight change and knee pain. A total of 22,948 participants were enrolled; those under the age of 50 and those who did not answer the questions about knee pain or weight change were excluded. In all, 8480 patients were analyzed, 7001 (82.56%) of whom indicated that they did not have knee pain, versus 1479 (17.44%) who did experience knee pain. Multivariate regression analysis was performed to analyze the association between knee pain and weight change. With full adjustment for covariates, weight gain per se (OR 1.37; p = 0.002), and gains of 3–6 kg (OR 1.28; p = 0.029) and ≥6 kg (OR 1.62; p = 0.012), showed significant associations with knee pain. This cross-sectional study confirmed a significant association between knee pain and weight change. Therefore, when evaluating patients with knee pain, it is necessary to evaluate weight gain.

Obesity, Bariatric Surgery, and Hip/Knee Arthroplasty Outcomes

Obesity is an independent risk factor for osteoarthritis due to mechanical and inflammatory factors. The gold-standard treatment of end-stage knee and hip osteoarthritis is total joint arthroplasty (TJA). Weight loss decreases progression of osteoarthritis and complications following TJA in patients with obesity. Bariatric surgery allows significant, sustained weight loss and comorbidity resolution in patients with morbid obesity. Existing data describing bariatric surgery on TJA outcomes are limited but suggest a benefit to bariatric surgery prior to TJA. Further studies are needed to determine optimal risk stratification, bariatric procedure selection, and timing of bariatric surgery relative to TJA.

Acute High-Intensity Interval Exercise Improves Inhibitory Control Among Young Adult Males With Obesity

Objective

The aim of the present study was to examine the influence of acute high-intensity interval exercise (HIIE) on neural and behavioral measures of inhibitory control in young male adults with obesity.

Design

The present study employed a within-subjects design.

Methods

Sixteen male adults with obesity [body mass index (BMI) > 28 kg/m²] were recruited. Reaction time and response accuracy of the Flanker task as well as P3 and late positive potential (LPP) components of the event-related potential (ERP) were measured following HIIE and a sedentary control, in counterbalanced order. The HIIE session consisted of 30 min of stationary cycle exercise (5-min warm-up, 20-min HIIE, and a 5-min cool-down), whereas the control condition consisted of a time and attention-matched sedentary resting session.

Results

Faster response times were observed following HIIE regardless of Flanker task condition. Faster and more accurate responses were also observed for congruent relative to incongruent conditions across both sessions. Relative to the neuroelectric data, acute HIIE resulted in increased LPP amplitude but did not affect P3 amplitude.

Conclusion

Collectively, a single bout of HIIE has a general beneficial effect on basic information processing and inhibitory control among young adult males with obesity. Acute HIIE was found to impact LPP amplitude, but not the P3, which may suggest a modulation in the ability to successfully maintain attention and filter irrelevant information to achieve successful cognitive inhibition. Future research is warranted to extend these findings to a larger sample size that includes both genders, other cognitive functions, and a comparison of different modes of exercise.

Cartilage Quality (dGEMRIC Index) Following Knee Joint Distraction or High Tibial Osteotomy

OBJECTIVE

High tibial osteotomy (HTO) and knee joint distraction (KJD) are treatments to unload the osteoarthritic (OA) joint with proven success in postponing a total knee arthroplasty (TKA). While both treatments demonstrate joint repair, there is limited information about the quality of the regenerated tissue. Therefore, the change in quality of the repaired cartilaginous tissue after KJD and HTO was studied using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC).

DESIGN

Forty patients (20 KJD and 20 HTO), treated for medial tibiofemoral OA, were included in this study. Radiographic outcomes, clinical characteristics, and cartilage quality were evaluated at baseline, and at 1- and 2-year follow-up.

RESULTS

Two years after KJD treatment, clear clinical improvement was observed. Moreover, a statistically significant increased medial (Δ 0.99 mm), minimal (Δ 1.04 mm), and mean (Δ 0.68 mm) radiographic joint space width (JSW) was demonstrated. Likewise, medial (Δ 1.03 mm), minimal (Δ 0.72 mm), and mean (Δ 0.46 mm) JSW were statistically significantly increased on radiographs after HTO. There was on average no statistically significant change in dGEMRIC indices over two years and no difference between treatments. Yet there seemed to be a clinically relevant, positive relation between increase in cartilage quality and patients' experienced clinical benefit.

CONCLUSIONS

Treatment of knee OA by either HTO or KJD leads to clinical benefit, and an increase in cartilage thickness on weightbearing radiographs for over 2 years posttreatment. This cartilaginous tissue was on average not different from baseline, as determined by dGEMRIC, whereas changes in quality at the individual level correlated with clinical benefit.

The Pressing Need to Raise Awareness about Osteoarthritis Care among Elderly Females in Pakistan: A Cross-sectional Study

Introduction

Osteoarthritis (OA) is the single-most common cause of physical disability among adults. In view of its promising management modalities, an analysis of the level of awareness among the suspected individuals and their attitudes is crucial to assess the level of their implementation. This study aimed to do that among the female population in Karachi, Pakistan.

Methods

This cross-sectional study was conducted among 316 elderly females (≥60 years) in Karachi in 2018. Data were collected via a structured questionnaire, which included sections titled: demographics, knowledge, attitudes, and practices. Data were analyzed using the Statistical Package for Social Sciences (version 20.20, IBM, Armonk, New York, US), and chi-square tests were used to assess the connection between OA care and socioeconomic statuses. Mean and standard deviation were calculated for quantitative variables.

Results

A considerable portion (48%, n = 152) of the participants were from a lower socioeconomic background, and 51% of them had a history of joint pain. Significantly, 63% of the participants (n = 199) attributed their joint pain to age, while nearly half attributed it to their diet and exercise habits. A major segment (73%, n = 230) of the participants, irrespective of their socioeconomic backgrounds, had visited a doctor for their joint complaints. Around 65% of the participants said they would never undergo a knee-joint replacement, regardless of how worse their symptoms might get. Additionally, 36% of the participants were unsatisfied with their current treatment, while more than half of the participants said that medication would improve their condition.

Conclusions

Our results demonstrate a connection between the lack of awareness about OA and the factors negatively affecting its management. They also point towards areas that require focused efforts for better awareness.

The Effect of Bariatric Surgery Prior to Lower-Extremity Total Joint Arthroplasty: A Systematic Review

BACKGROUND

Obesity is an independent risk factor for osteoarthritis and has been associated with increased rate of complications following lower-extremity total joint arthroplasty (TJA). Bariatric surgery (BS) is a surgical option for weight loss and for reducing obesity-related comorbidities in morbidly obese patients.

PURPOSE/QUESTIONS

The goal of this systematic review was to answer the following questions: (1) Does BS prior to TJA correlate with lower post-operative complication rates in morbidly obese patients undergoing TJA? (2) Does BS have an impact on revision rates following TJA?

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and checklist, a systematic review of medical databases (PubMed/ MEDLINE, Cochrane Library, Web of Science, and Clinicaltrials.gov) was undertaken for articles published in English from January 1990 to September 2018. Inclusion criteria were studies that included at least ten patients who underwent BS prior to TJA, collected data on complications or other outcomes, and followed patients for at least 90 days after TJA. A descriptive and critical analysis of the results was performed.

RESULTS

From 799 studies, 13 met inclusion criteria. A total of 11,770 patients who had undergone bariatric surgery prior to TJA were analyzed. The quality of the evidence ranged between moderate and high. There was no consensus on the effect of previous BS on early- to short-term outcomes reported after TJA.

CONCLUSION

The literature remains conflicted on the impact of BS prior to TJA on early, short-term, and long-term complications after TJA. Additional well-matched, observational studies may further our understanding of the impact of BS prior to TJA on outcomes. In particular the effect of various types of BS prior to TJA on outcomes has yet to be elucidated. Ideally, prospective studies with higher level of evidence will be more definitive on the effects of BS prior to TJA.Prospero Registration Number: CRD42016043025.

The Impact of Medical Comorbidities on Primary Total Knee Arthroplasty Reimbursements

Medical comorbidities have been shown to cause an increase in peri-and postoperative complications following total knee arthroplasty (TKA). However, the increase in cost associated with these complications has yet to be determined. Factors that influence cost have been of great interest particularly after the initiation of bundled payment initiatives. In this study, we present and quantify the influence of common medical comorbidities on the cost of care in patients undergoing primary TKA. A retrospective level of evidence III study was performed using the PearlDiver supercomputer to identify patients who underwent primary TKA between 2007 and 2015. Patients were stratified by medical comorbidities and compared using analysis of variance for reimbursements for the day of surgery and over 90 days postoperatively. A cohort of 137,073 US patients was identified as having undergone primary TKA between 2007 and 2015. The mean entire episode-of-care reimbursement was $23,701 (range: $21,294-26,299; standard deviation [SD] $2,611). The highest reimbursements were seen in patients with chronic obstructive pulmonary disease (mean $26,299; SD $3,030), hepatitis C (mean $25,662; SD $2,766), morbid obesity (mean $25,450; SD $2,154), chronic kidney disease (mean $25,131, $3,361), and cirrhosis (mean $24,890; SD $2,547). Medical comorbidities significantly impact reimbursements, and therefore cost, after primary TKA. Comprehensive preoperative optimization for patients with medical comorbidities undergoing TKA is highly recommended and may reduce perioperative complications, improve patient outcome, and ultimately reduce cost.

Effectiveness of Cucumis sativus extract versus glucosamine-chondroitin in the management of moderate osteoarthritis: a randomized controlled trial

Purpose

Osteoarthritis (OA) is an age-related disease caused by the wear and tear of the joints. Presently, there is no known cure for OA, but its management involves the use of high doses of pain killers and antiinflammatory agents with different side and dependency effects. Alternative management strategies involve the use of high doses of glucosamine-chondroitin (GC). This study was carried out to evaluate the efficacy of Q-Actin™, an aqueous extract of Cucumis sativus (cucumber; CSE) against GC in the management of moderate knee OA.

Patients and methods

Overall, 122 patients (56 males and 66 females) aged between 40 and 75 years and diagnosed with moderate knee OA were included in this randomized double-blind, parallel-group clinical trial that took place in three different centers. The 180 day intervention involved two groups of 61 participants in each: the GC group, which received orally the generally prescribed dose of 1,350 mg of GC twice daily and the CSE group, which received orally10 mg twice daily of CSE. The Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog scale, and Lequesne's Functional Index were used to evaluate pain, stiffness, and physical function of knee OA in participants at baseline (Day 0) and on Days 30, 60, 90, 120, 150, and 180.

Results

In the CSE group, the WOMAC score was decreased by 22.44% and 70.29% on Days 30 and 180, respectively, compared to a 14.80% and 32.81% decrease in the GC group. Similar trends were observed for all the other pain scores. No adverse effect was reported during the trial period.

Conclusion

The use of 10 mg CSE, twice daily, was effective in reducing pain related to moderate knee OA and can be potentially used in the management of knee pain, stiffness, and physical functions related to OA.

Females, younger patients and patients with high BMI have the highest pre-operative knee awareness measured using the Forgotten Joint Score

PURPOSE

The Forgotten Joint Score (FJS) is a novel measurement for patients' awareness of their knee in daily life. By identifying factors that could explain pre-operative FJS levels, the clinician could better prioritize and single out patients who would benefit most from TKA. The aim of this study was to identify possible factors that may explain the variance of pre-operative FJS levels and evaluate the relationship between pre-operative FJS and pre-operative Oxford Knee Score (OKS).

METHODS

Four-hundred and six individual knees undergoing primary TKA between 2014 and 2016 were included in the study. Age, gender, body mass index (BMI), pre-operative FJS and pre-operative OKS were obtained maximum 2 weeks prior to surgery. Kellgren-Lawrence (K-L) grade, alignment and joint space width (JSW) were evaluated on pre-operative radiographs.

RESULTS

Mean FJS was 21.1 ± 15.6. Females, younger patients and patients with high BMI had significantly the worst pre-operative FJS (p < 0.005). Females scored 6.5 FJS points lower than males. A 0.2-point increase in FJS for every added year indicated improvement in knee awareness with age. A 0.4-point decrease in FJS points for every added BMI point indicated worse knee awareness with higher BMI. There was a strong positive correlation between pre-operative FJS and pre-operative OKS according to the Spearman's rank order test (p < 0.005).

CONCLUSIONS

Females, younger patients and patients with high BMI had significantly the worst pre-operative joint awareness. FJS had a strong positive correlation to OKS in pre-operative patients for primary TKA. This information can be used for improved patient selection; clinically continuous low FJS despite weight loss and/or the passing of time may be indication for TKA.

LEVEL OF EVIDENCE

Prospective cohort study, Level II.

Preferences and motivation for weight loss among knee replacement patients: implications for a patient-centered weight loss intervention

BACKGROUND

Most knee replacement patients are overweight/obese, yet are commonly excluded from evidence-based weight loss programs due to mobility limitations and barriers faced around the time of surgery. The purpose of this study was to identify knee replacement patient preferences for weight loss programs and qualitatively understand previous motives for weight loss attempts as well as strategies used to facilitate behavior changes.

METHODS

Patients who were either scheduled to have knee replacement or had one recently completed within the last 3 months were recruited to participate. Patients completed a brief weight loss program preference questionnaire assessing preferred components of a weight loss program (i.e. self-monitoring, educational topics, program duration). Qualitative interviews were completed to identify motives for and strategies used during past weight loss attempts. All interviews were transcribed, de-identified, and analyzed using constant comparative analysis.

RESULTS

Twenty patients (11 pre-operative and 9 post-operative) between 47 and 79 years completed the study (55% male, 90% White, and 85% with a BMI ≥25 kg/m²). Patients reported a preference for a weight loss program that starts before surgery, is at least 6 months in duration, and focuses both on diet and exercise. The majority of patients preferred to have a telephone-based program and wanted to track diet and physical activity on a smartphone application. The most common motive for weight loss mentioned by patients related to physical appearance (including how clothing fit), followed by wanting to lose weight to improve knee symptoms or to prevent or delay knee replacement. Strategies that patients identified as helpful during weight loss attempts included joining a formal weight loss program, watching portion sizes, and self-monitoring their dietary intake, physical activity, or weight.

CONCLUSIONS

This study provides a preliminary examination into the motives for weight loss, strategies utilized during past weight loss attempts, and preferences for future weight loss programs as described by knee replacement patients. These results will help guide the development and adaptation of future patient-centered weight loss programs as well as help clinicians recommend targeted weight programs based on the specific preferences of the knee replacement population.

Influence of Body Mass Index on Sagittal Knee Range of Motion and Gait Speed Recovery 1-Year After Total Knee Arthroplasty

BACKGROUND

The purpose of this prospective study was to investigate the influence of body mass index (BMI) on gait parameters preoperatively and 1 year after total knee arthroplasty (TKA).

METHODS

Seventy-nine patients were evaluated before and 1 year after TKA using clinical gait analysis. The gait velocity, the knee range of motion (ROM) during gait, their gains (difference between baseline and 1 year after TKA), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quality of life, and patient satisfaction were assessed. Nonobese (BMI <30 kg/m²) and obese patients (BMI ≥30 kg/m²) were compared. Healthy controls were also assessed. Univariate and multivariate linear regression analyses were used to assess the association between gait speed and ROM gains. Adjustment was performed for gender, age, and WOMAC pain improvement.

RESULTS

At baseline, gait velocity and knee ROM were significantly lower in obese compared with those in the nonobese patients (0.99 ± 0.27 m/s vs 1.11 ± 0.18 m/s; effect size, 0.53; P = .021; and ROM, 41.33° ± 9.6° vs 46.05° ± 8.39°; effect size, 0.52; P = .022). Univariate and multivariate linear regressions did not show any significant relation between gait speed gain or knee ROM gain and BMI. At baseline, obese patients were more symptomatic than nonobese (WOMAC pain: 36.1 ± 14.0 vs 50.4 ± 16.9; effect size, 0.9; P < .001), and their improvement was significantly higher (WOMAC pain gain, 44.5 vs 32.3; effect size, 0.59; P = .011).

CONCLUSION

These findings show that all patients improved biomechanically and clinically, regardless of their BMI.

Long-Term Safety and Efficacy of Fulranumab in Patients With Moderate-to-Severe Osteoarthritis Pain: A Phase II Randomized, Double-Blind, Placebo-Controlled Extension Study

OBJECTIVE

To evaluate the long-term safety and efficacy of fulranumab in patients with knee or hip pain caused by moderate-to-severe chronic osteoarthritis (OA).

METHODS

In this phase II double-blind, placebo-controlled extension study, patients who were randomized in equal proportions to receive subcutaneous doses of either placebo or fulranumab (1 mg every 4 weeks, 3 mg every 8 weeks, 3 mg every 4 weeks, 6 mg every 8 weeks, or 10 mg every 8 weeks) in the 12-week double-blind efficacy phase and who completed this double-blind efficacy phase were eligible to continue the dosage throughout a 92-week double-blind extension phase, followed by a 24-week posttreatment follow-up period. Safety assessments included evaluation of treatment-emergent adverse events (TEAEs), pre-identified AEs of interest, and joint replacements. Efficacy assessments included changes from baseline to the end of the double-blind extension phase in scores on the patient's global assessment and the pain and physical function subscales of the Western Ontario and McMaster Universities Osteoarthritis Index.

RESULTS

Overall, 401 of the 423 patients who completed the 12-week double-blind efficacy phase entered the extension study. Long-term sustained improvements were observed in all efficacy parameters following fulranumab treatment (1 mg every 4 weeks, 3 mg every 4 weeks, and 10 mg every 8 weeks) as compared with placebo. Similar percentages of patients in both groups experienced TEAEs (88% taking placebo and 91% taking fulranumab; all phases). Across all fulranumab groups, arthralgia (21%) and OA (18%) (e.g., exacerbation of OA pain) were the most common TEAEs. The most common serious TEAEs were the requirement for knee (10%) and hip (7%) arthroplasty, with 80% occurring during the posttreatment follow-up period. Neurologic-related TEAEs (28%; all phases) were generally mild-to-moderate. Overall, 81 joint replacements were performed in 71 patients (8 [11%] receiving placebo and 63 [89%] receiving fulranumab); 15 patients (21%) had rapid progression of OA (RPOA). All cases of RPOA occurred in fulranumab-treated patients who were concurrently receiving nonsteroidal antiinflammatory drugs and occurred in joints with preexisting OA.

CONCLUSION

Long-term treatment with fulranumab was generally well-tolerated and efficacious. RPOA was observed as a safety signal. Future studies are warranted to demonstrate whether the risk of RPOA can be reduced in patients taking fulranumab.

A new treatment for knee osteoarthritis: Clinical evidence for the efficacy of Arthrokinex™ autologous conditioned serum

OBJECTIVE

The desired therapeutic effect of Arthrokinex™ autologous conditioned serum (ACS) is facilitated by the ability of IL-1-Ra to limit the destructive inflammatory intra-articular (IA) actions of IL-1β. Previous studies have proven the capacity of Arthrokinex™ (ACS) to induce the anti-inflammatory cytokine, IL-1-Ra. The primary purpose of this retrospective study was to investigate the effect of Arthrokinex™ (ACS) to reduce pain, improve joint function and enhance quality of life in patients with knee osteoarthritis.

METHODS

Venous blood from 100 patients with symptomatic knee osteoarthritis (KOA) was conditioned and injected into the affected joint in this treatment protocol. Each patient received a total of six ultrasound-guided IA injections at day 0, 7, 14, 90, 180, and 270 and followed for up to one year. Treatment outcome measures were assessed by three different patient-administered surveys at each visit. Using the Visual Analog Pain Scale (VAS), participants were asked to classify pain in the previous 24 h. The Extra Short Musculoskeletal Functional Assessment (XSMFA-D) survey is a series of 16 questions designed to determine the functionality of the OA-affected joint. Finally, the patient completed a patient global impression of change (PGIC) survey to assess their individual level of satisfaction with the treatment regimen.

RESULTS

Compared to baseline, a total of 84% of patients reported better pain control at 6 months with 91% reporting improvement at 12 months. A robust and statistically significant improvement in each XSMFA-D subscale was observed in KOA patients over 12 months. The overall reduction of pain and enhanced joint function was observed within 1 week and sustained 3, 6 and even 12 months after the initial injection. In addition to symptomatic control of OA, 92% of patients reported satisfaction with the treatment regimen 12 months after the initial injection.

CONCLUSION

Given the favorable safety profile, reduction in pain and enhanced quality of life experienced by patients enrolled in this joint health program, Arthrokinex™ (ACS) has the potential to offer an alternative, chondroprotective, natural, molecular approach to treating pain and functionality in patients with mild, moderate or severe knee osteoarthritis.

Lingering Risk: Bariatric Surgery Before Total Knee Arthroplasty

BACKGROUND

Obesity continues to increase in the United States with an estimated 35% obesity and 8% bariatric (body mass index >40) rate in adults. Bariatric patients seek advice from arthroplasty surgeons regarding the temporality of bariatric surgery (BS), yet no consensus currently exists in the literature.

METHODS

A total of 39,014 patients were identified in a claim-based review of the entire Medicare database with International Classification of Diseases, Ninth Revision codes to identify patients in 3 groups. Patients who underwent BS before total knee arthroplasty (group I: 5914 experimental group) and 2 control groups that did not undergo BS but had either a body mass index >40 (group II: 6480 bariatric control) or <25 (group III: 26,616 normal weight control). International Classification of Diseases, Ninth Revision, Clinical Modification codes identified preoperative demographics or comorbidities and evaluated short-term medical (30 day) and long-term surgical (90 days and 2 years) complications.

RESULTS

Group I had the greatest female predominance, youngest age, and highest incidence of: deficiency anemia, cardiovascular disease, pulmonary disease, liver disease, ulcer disease, polysubstance abuse, psychiatric disorders, and smoking. Medical and surgical complication incidences were greatest in group I including: 4.98% deep vein thrombosis; 5.31% pneumonia; 10.09% heart failure; and 2-year infection, revision, and manipulation rates of 5.8%, 7.38%, and 3.13%, respectively. These values were significant elevation compared to III and slightly greater than II.

CONCLUSIONS

This study demonstrates that BS before total knee arthroplasty is associated with greater risk compared to both nonobese and obese patients. This is possibly due to a higher incidence of medical or psychiatric comorbidities determined in the Medicare BS patients, wound healing difficulties secondary to gastrointestinal malabsorption, malnourishment from prolonged catabolic state, rapid weight loss before surgery, and/or age.

Risk factors for periprosthetic joint infection following primary total hip or knee arthroplasty: a meta-analysis

To identify risk factors for periprosthetic joint infection following primary total joint arthroplasty, a systematic search was performed in Pubmed, Embase and Cochrane library databases. Pooled odds ratios (ORs) or standardised mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. Patient characteristics, surgical-related factors and comorbidities, as potential risk factors, were investigated. The main factors associated with infection after total joint arthroplasty (TJA) were male gender (OR, 1·48; 95% CI, 1.19-1.85), age (SMD, -0·10; 95% CI, -0.17--0.03), obesity (OR, 1·54; 95% CI, 1·25-1·90), alcohol abuse (OR, 1·88; 95% CI, 1·32-2·68), American Society of Anesthesiologists (ASA) scale > 2 (OR, 2·06; 95% CI, 1·77-2·39), operative time (SMD, 0·49; 95% CI, 0·19-0·78), drain usage (OR, 0·36; 95% CI, 0·18-0·74), diabetes mellitus (OR, 1·58; 95% CI, 1·37-1·81), urinary tract infection (OR, 1·53; 95% CI, 1.09-2.16) and rheumatoid arthritis (OR, 1·57; 95% CI, 1·30-1·88). Among these risk factors, ASA score > 2 was a high risk factor, and drain usage was a protective factor. There was positive evidence for some factors that could be used to prevent the onset of infection after TJA.

No association of the single nucleotide polymorphism rs8044769 in the fat mass and obesity-associated gene with knee osteoarthritis risk and body mass index: A population-based study in China

OBJECTIVES

Previous genome-wide association studies (GWAS) have reported significant association of the single nucleotide polymorphism (SNP) rs8044769 in the fat mass and obesity-associated gene (FTO) with osteoarthritis (OA) risk in European populations. However, these findings have not been confirmed in Chinese populations.

METHODS

We systematically genotyped rs8044769 and evaluated the association between the genetic variants and OA risk in a case-controlled study including 196 OA cases and 442 controls in a northern Chinese population. Genotyping was performed using the Sequenom MassARRAY iPLEX platform.

RESULTS

We found that the variant T allele of rs8044769 showed no significant association of OA risk (p = 0.791), or association with body mass index (BMI) (pmeta = 0.786) in an additive genetic model. However, we detected a significant interaction between rs8044769 genotypes and BMI on OA risk (p = 0.037), as well as a borderline interaction between rs8044769 genotypes and age on OA risk (p = 0.062).

CONCLUSIONS

Our findings indicate that rs8044769 in the FTO gene may not modify individual susceptibility to OA or increased BMI in the Chinese population. Further studies are warranted to validate and extend our findings.Cite this article: Prof L. Jiang. No association of the single nucleotide polymorphism rs8044769 in the fat mass and obesity-associated gene with knee osteoarthritis risk and body mass index: A population-based study in China. Bone Joint Res 2016;5:169-174. DOI: 10.1302/2046-3758.55.2000589.

The Utility of Increased Constraint in Primary Total Knee Arthroplasty for Obese Patients

Total knee arthroplasty (TKA) for obese patient entails more preoperative comorbidities and complications, and shorter longevity. This article is a retrospective review comparing longevity of the constrained implant with a standard prosthesis. Patient-specific data, Knee Society Scores, complications, and revisions were recorded and compared. No statistical differences were found. The constrained condylar knee for obese patients improves the intramedullary alignment of the prosthesis and supports the surrounding soft tissues. The clinical results are similar to a standard implant in the nonobese with similar longevity at midterm follow-up.

[Knee dysfunction in the general population and associated factors]

BACKGROUND

Knee joint dysfunction is present in 80% of people over 50 years of age, and in women there is a 1.5 times higher risk compared to men. Another important risk factor is obesity, which leads to a 3 times increase in the risk of suffering functional limitations in the joint. The aim of this study was to determine knee joint dysfunction and the associated factors.

MATERIAL AND METHODS

An analytical and descriptive study was conducted on 218 individuals older than 50 years of age in a primary care centre. A physical examination was performed on each patient, and the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire was applied to them all. Logistic regression analysis was used to determine the association between age, gender, body mass index, and knee function. ANOVA was used to compare the means of the Western Ontario and McMaster Universities Osteoarthritis Index scores and body mass index measurements. A p<0.05 was considered statistically significant.

RESULTS

The mean age was 64.27 years (SD 10.43). An OR of 4.50 was obtained for having a disability in people over 65 years of age, 2.90 in obese people, and 2.02 in women. The mean scores in the 3 domains of Western Ontario and McMaster Universities Osteoarthritis Index were higher as the body mass index increased.

CONCLUSIONS

Women have greater disability than men, becoming more evident in older ages, and other risk of joint dysfunction increases up 3 times in obese patients.

Effect of antiresorptive and anabolic bone therapy on development of osteoarthritis in a posttraumatic rat model of OA

Introduction

Osteoarthritis (OA) is a leading cause of disability, but despite the high unmet clinical need and extensive research seeking dependable therapeutic interventions, no proven disease-modifying treatment for OA is currently available. Due to the close interaction and interplay between the articular cartilage and the subchondral bone plate, it has been hypothesized that antiresorptive drugs can also reduce cartilage degradation, inhibit excessive turnover of the subchondral bone plate, prevent osteophyte formation, and/or that bone anabolic drugs might also stimulate cartilage synthesis by chondrocytes and preserve cartilage integrity. The benefit of intensive zoledronate (Zol) and parathyroid hormone (PTH) therapy for bone and cartilage metabolism was evaluated in a rat model of OA.

Methods

Medial meniscectomy (MM) was used to induce OA in male Lewis rats. Therapy with Zol and human PTH was initiated immediately after surgery. A dynamic weight-bearing (DWB) system was deployed to evaluate the weight-bearing capacity of the front and hind legs. At the end of the 10-week study, the rats were euthanized and the cartilage pathology was evaluated by contrast (Hexabrix)-enhanced μCT imaging and traditional histology. Bone tissue was evaluated at the tibial metaphysis and epiphysis, including the subchondral bone. Histological techniques and dynamic histomorphometry were used to evaluate cartilage morphology and bone mineralization.

Results

The results of this study highlight the complex changes in bone metabolism in different bone compartments influenced by local factors, including inflammation, pain and mechanical loads. Surgery caused severe and extensive deterioration of the articular cartilage at the medial tibial plateau, as evidenced by contrast-enhanced μCT and histology. The study results showed the negative impact of MM surgery on the weight-bearing capacity of the operated limb, which was not corrected by treatment. Although both Zol and PTH improved subchondral bone mass and Zol reduced serum CTX-II level, both treatments failed to prevent or correct cartilage deterioration, osteophyte formation and mechanical incapacity.

Conclusions

The various methods utilized in this study showed that aggressive treatment with Zol and PTH did not have the capacity to prevent or correct the deterioration of the hyaline cartilage, thickening of the subchondral bone plate, osteophyte formation or the mechanical incapacity of the osteoarthritic knee.

Inflammatory biomarkers in osteoarthritis

Osteoarthritis (OA) is highly prevalent and a leading cause of disability worldwide. Despite the global burden of OA, diagnostic tests and treatments for the molecular or early subclinical stages are still not available for clinical use. In recent years, there has been a large shift in the understanding of OA as a "wear and tear" disease to an inflammatory disease. This has been demonstrated through various studies using MRI, ultrasound, histochemistry, and biomarkers. It would of great value to be able to readily identify subclinical and/or sub-acute inflammation, particularly in such a way as to be appropriate for a clinical setting. Here we review several types of biomarkers associated with OA in human studies that point to a role of inflammation in OA.

Bariatric Surgery Prior to Total Knee Arthroplasty is Associated With Fewer Postoperative Complications

This study used a national database to compare 90-day postoperative complication rates between three groups of patients who underwent total knee arthroplasty (TKA): (1) non-obese patients (n=66,523), (2) morbidly obese patients who did not have bariatric surgery (n=11,294) and (3) morbidly obese patients who underwent bariatric surgery prior to TKA (n=219). Morbidly obese patients who underwent bariatric surgery prior to TKA had reduced rates of major (OR 0.45, P=0.001) and minor (OR 0.61, P=0.01) complications compared to morbidly obese patients who did not have bariatric surgery. Bariatric surgery prior to TKA appears to be associated with less risk of postoperative complications, although not to the same level as non-obese patients.

Primary Total Knee Arthroplasty in Super-obese Patients: Dramatically Higher Postoperative Complication Rates Even Compared to Revision Surgery

This study utilized a national database to evaluate 90 day postoperative complication rates after total knee arthroplasty (TKA) in super obese (BMI > 50 kg/m(2)) patients (n = 7666) compared to non-obese patients (n = 1,212,793), obese patients (n = 291,914), morbidly obese patients (n = 169,308) and revision TKA patients (n = 28,812). Super obese patients had significantly higher rates of local and systemic complications compared to all other BMI groups as well as those undergoing revision TKA with higher rates of venous thromboembolism (VTE), infection, and medical complications. Super obesity is associated with dramatically increased rates of postoperative complications after TKA compared to non-obese, obese, and morbidly obese patients as well as those undergoing revision TKA.