Obesity increases the likelihood of total joint replacement surgery among younger adults

Correlation between body mass index and functional outcome of total knee replacement for osteoarthritis of knee- a prospective study on South Indian cohort

Background

Over the past 20 years, there has been an increase in demand for complete knee replacements, and this trend is predicted to continue. It has been shown that being overweight is a risk factor for knee osteoarthritis. There are only a few studies on this in India and none on South Indian patients, Therefore, our goal was to evaluate how BMI affected functional outcomes after primary total knee replacement.

Objectives

To determine the impact of body mass index (BMI) on functional outcomes after primary total knee replacement.

Method

ology: Patients who underwent total knee replacement between November 2021 and November 2023 were included in the study. Patients were divided into groups based on BMI. Group I patients have a BMI less than 25, and group II patients of BMI greater than 25. International Knee Society scoring(IKSS) is used to assess patients Preoperatively and postoperatively.

Results

Out of 185 patients, 70 were males and 115 were females. When IKSS scores were analyzed the mean Knee score before surgery in Group 1 was 24.58 and in Group 2 it was 16.64. After 1 year follow up the mean scores were 68.5 and 57.5 respectively. When analyzed with functional score the pre-op scores for groups 1 and 2 were 32.58 and 23.44 respectively and post-op scores after one-year follow-up were 71.17 and 51.7 respectively.

Conclusion

BMI does have a positive correlation with both preoperative and postoperative scores. A weight-loss programme can be discussed with the patients presenting the results of this study.

Comparison of regional vs. general anesthesia on the risk of dementia: a systematic review and meta-analysis

Background

Dementia is a gradual and ongoing cognitive decline due to damage to nerve cells in the brain. This meta-analysis aimed to assess the potential relationship between regional anesthesia (RA) and the risk of dementia.

Methods

Electronic databases including Embase, Medline, Google Scholar, and Cochrane Library were searched for studies investigating the association between RA and dementia risk from inception to March 2022. The primary outcome was the risk of dementia in patients who underwent RA (RA group) and those who received general anesthesia (GA group). Secondary outcomes included identifying other potential risk factors for dementia and comparing dementia risk between individuals receiving RA and those not receiving surgery/anesthesia (placebo group).

Results

Eight cohort studies published between 2014 and 2023 were included in this analysis. A meta-analysis of the available data demonstrated no differences in baseline characteristics and morbidities (i.e., age, male proportion, hypertension, diabetes, depression, and severe comorbidities) between the RA and GA groups (all p > 0.05). Initial analysis revealed that the risk of dementia was higher in the GA group than in the RA group (HR = 1.81, 95% CI = 1.29-2.55, p = 0.007, I 2 = 99%, five studies). However, when a study featuring a relatively younger population was excluded from the sensitivity analysis, the results showed a similar risk of dementia (HR, 1.17; p = 0.13) between the GA and RA groups. The pooled results revealed no difference in dementia risk between the RA and placebo groups (HR = 1.2, 95% CI = 0.69-2.07, p = 0.52, I 2 = 68%, three studies). Sensitivity analysis revealed that the evidence was not stable, suggesting that limited datasets precluded strong conclusions on this outcome. Anxiety, stroke history, hypertension, diabetes, hyperlipidemia, and diabetes are potential predictors of dementia.

Conclusion

Our results emphasize that, while RA could be protective against dementia risk compared to GA, the association between the type of anesthesia and dementia risk might vary among different age groups. Owing to the significant prevalence of dementia among older people and their surgical needs, further investigations are warranted to clarify the association between dementia risk and regional anesthesia.Systematic review registration: https://www.crd.york.ac.uk/prospero/, CRD42023411324.

The obesity challenge in joint replacement: a multifaceted analysis of self-reported health status and exercise capacity using NHANES data: a population-based study

BACKGROUND

Joint replacement is successful for end-stage oeteoarthritis, with obesity linked to elevated risk. But the impact of obesity on self-reported health and exercise capacity among joint replacement patients remains complex and requires investigation.

METHODS

This study utilizes data from the National Health and Nutrition Examination Survey (NHANES) to examine the relationship between obesity severity, demographic factors, medical comorbidities, and self-reported health status. The relationship between general health status and BMI was analyzed using multivariable regression, and further illustrated using a restricted cubic spline. Additionally, a bibliometric analysis and systematic review was done to frame the research within the broader context of existing knowledge and demographic specifics.

RESULTS

Analysis of NHANES data involving 327 joint replacement patients yielded intriguing insights. The difference in self-reported health between BMI groups did not achieve conventional statistical significance ( P =0.06), and multivariable analysis showed that even severely obese patients did not exhibit significantly elevated risk of poor/fair self-reported health compared to normal weight subjects. Among severely obese individuals (BMI>40), 40.63% still rated their health positively. However, stratified analyses indicated that obesity correlated with negative health reports across sex, age, and education strata. Notably, physical functioning emerged as a robust predictor of self-reported health, with those reporting no walking difficulties having significantly lower odds of poor/fair health (Odds ratio=0.37, P =0.01).

CONCLUSION

The study highlights the need for healthcare providers to consider individual physical abilities and comorbidities alongside obesity severity when discussing treatment options with joint replacement patients. It supports tailored interventions and informed shared decision-making. Future research could explore effective weight management strategies for obese individuals undergoing joint replacement.

Nanotextured titanium inhibits bacterial activity and supports cell growth on 2D and 3D substrate: A co-culture study

Medical implant-associated infections pose a significant challenge to modern medicine, with aseptic loosening and bacterial infiltration being the primary causes of implant failure. While nanostructured surfaces have demonstrated promising antibacterial properties, the translation of their efficacy from 2D to 3D substrates remains a challenge. Here, we used scalable alkaline etching to fabricate nanospike and nanonetwork topologies on 2D and laser powder-bed fusion printed 3D titanium. The fabricated surfaces were compared with regard to their antibacterial properties against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and mesenchymal stromal cell responses with and without the presence of bacteria. Finite elemental analysis assessed the mechanical properties and permeability of the 3D substrate. Our findings suggest that 3D nanostructured surfaces have potential to both prevent implant infections and allow host cell integration. This work represents a significant step towards developing effective and scalable fabrication methods on 3D substrates with consistent and reproducible antibacterial activity, with important implications for the future of medical implant technology.

Does rapid mobilisation as part of an enhanced recovery pathway improve length of stay, return to function and patient experience post primary total hip replacement? A randomised controlled trial feasibility study

PURPOSE

Day-zero ambulation may enable patients to recover and leave hospital quicker following total hip replacement (THR). The present randomised control feasibility study investigated the efficacy of day-zero ambulation as a physiotherapeutic intervention.

METHODS

Thirty-six non-blinded adults aged 44-85 (Mean 67.1; SD 9.6 years) undergoing primary, uncomplicated THR were block randomized to either a control group (n = 18) with standard post-operative physiotherapy or an intervention group (n = 18) incorporating walking on the same day as the operation. Outcomes were length of hospital stay (LOS), time to reach functional milestones and achieve all physiotherapy discharge criteria, post-operative pain scores, complications and patient experience.

RESULTS

Participants treated with day-zero ambulation had reduced median hospital LOS of 1 day (p = .096), and median reduced times to reaching functional milestones of 39.7 h quicker to transfer to a chair (p < .001), 24.5 h quicker to walk 10 m (p = .009) and 26.4 h quicker to independently ascend and descend stairs (p = .01). Participants in the intervention group were deemed physiotherapy ready to leave hospital significantly earlier than control group (1.04 days, p = .015).

CONCLUSIONS

Day-zero ambulation appears safe and may have clinically relevant effects in speeding patient functional recovery and facilitating earlier discharge from hospital. Implications for RehabilitationDay-zero ambulation following total hip replacement (THR) appears safe.Preliminary data suggest that day-zero mobilisation following THR could be efficacious and support the need for a fully powered randomised controlled trial.There may be a clinically relevant effect in speeding patient functional recovery and facilitating an earlier discharge from hospital.

The burden of osteoarthritis: Is it a rising problem?

The objective of this review is to provide an overview of the current status of osteoarthritis (OA) as one of the most common joint disorders worldwide. Despite being the 11th cause of disability globally, there has been an increase in the prevalence, annual incidence, and years lived with disability of OA, particularly in developed and developing countries. Erosive hand OA, which affects approximately 10% of the general population, has been associated with a higher clinical burden compared to non-erosive hand OA. Patients with knee and hip OA, but not hand OA, are also at an increased risk of cardiovascular disease and all-cause mortality. Furthermore, OA has a significant contribution to healthcare costs in most countries. The recent COVID-19 pandemic has further exacerbated the disease burden of OA patients due to limited access to medical and surgical treatment. With increasing life expectancy and the aging of the global population, the burden of OA is expected to worsen. Therefore, this review highlights the importance of improving population and policymaker awareness of risk factors, such as obesity and injury, as well as early intervention and management of OA to control the future burden of the disease.

Outcomes of morbidly obese patients undergoing total hip arthroplasty with the anterior-based muscle-sparing approach

Obesity is associated with an increased risk of hip osteoarthritis, resulting in an increased number of total hip arthroplasties (THAs) performed annually. This study examines the peri- and postoperative outcomes of morbidly obese (MO) patients (BMI ≥ 40 kg/m²) compared to healthy weight (HW) patients (BMI 18.5 to < 25 kg/m²) who underwent a THA using the anterior-based muscle-sparing (ABMS) approach. This retrospective cohort study observes peri- and postoperative outcomes of MO and HW patients who underwent a primary, unilateral THA with the ABMS approach. Data from surgeries performed by three surgeons at a single institution was collected from January 2013 to August 2020 and analyzed using Microsoft Excel and Stata 17.0. This study compares 341 MO to 1,140 HW patients. Anaesthesia, surgery duration, and length of hospital stay was significantly lower in HW patients compared to MO. There was no difference in incidence of pulmonary embolism, periprosthetic fracture, or dislocation between the two groups. The rate of infection in MO patients (1.47%) was significantly higher than HW patients (0.14%). Preoperative patient-reported outcome measures (PROMs) show a significantly higher pain level in MO patients and a significantly lower score in functional abilities. Overall, six-week and one-year postoperative data show higher levels of pain, lower levels of functional improvement, and lower satisfaction scores in the MO group. The comorbidities of obesity are well studied; however, the implications of THA using the ABMS approach have not been studied. Our peri- and postoperative results demonstrate significant improvements in PROMs in MO patients undergoing THA. However, the incidence of deep infection was significantly higher in this group compared with HW patients.

Total Hip and Knee Arthroplasty Surgery in the Morbidly Obese Patient: A Critical Analysis Review

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Obesity, defined as body mass index (BMI) ≥30, is a serious public health concern associated with an increased incidence of stroke, diabetes, mental illness, and cardiovascular disease resulting in numerous preventable deaths yearly.

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From 1999 through 2018, the age-adjusted prevalence of morbid obesity (BMI ≥40) in US adults aged 20 years and older has risen steadily from 4.7% to 9.2%, with other estimates showing that most of the patients undergoing hip and knee replacement by 2029 will be obese (BMI ≥30) or morbidly obese (BMI ≥40).

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In patients undergoing total joint arthroplasty (TJA), morbid obesity (BMI ≥40) is associated with an increased risk of perioperative complications, including prosthetic joint infection and mechanical failure necessitating aseptic revision.

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The current literature on the role that bariatric weight loss surgery before TJA has on improving surgical outcomes is split and referral to a bariatric surgeon should be a shared-decision between patient and surgeon on a case-by-case basis.

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Despite the increased risk profile of TJA in the morbidly obese cohort, these patients consistently show improvement in pain and physical function postoperatively that should be considered when deciding for or against surgery.

Enhanced and Stem-Cell-Compatible Effects of Nature-Inspired Antimicrobial Nanotopography and Antimicrobial Peptides to Combat Implant-Associated Infection

Nature-inspired antimicrobial surfaces and antimicrobial peptides (AMPs) have emerged as promising strategies to combat implant-associated infections. In this study, a bioinspired antimicrobial peptide was functionalized onto a nanospike (NS) surface by physical adsorption with the aim that its gradual release into the local environment would enhance inhibition of bacterial growth. Peptide adsorbed on a control flat surface exhibited different release kinetics compared to the nanotopography, but both surfaces showed excellent antibacterial properties. Functionalization with peptide at micromolar concentrations inhibited Escherichia coli growth on the flat surface, Staphylococcus aureus growth on the NS surface, and Staphylococcus epidermidis growth on both the flat and NS surfaces. Based on these data, we propose an enhanced antibacterial mechanism whereby AMPs can render bacterial cell membranes more susceptible to nanospikes, and the membrane deformation induced by nanospikes can increase the surface area for AMPs membrane insertion. Combined, these effects enhance bactericidal activity. Since functionalized nanostructures are highly biocompatible with stem cells, they make promising candidates for next generation antibacterial implant surfaces.

Association of hormone replacement therapy and the risk of knee osteoarthritis: A meta-analysis

BACKGROUND

The relationship between hormone replacement therapy (HRT) and osteoarthritis is controversial in epidemiological studies. With the aim of better understanding the effect of HRT use, this first meta-analysis was implemented to explore the association of HRT and knee OA.

METHODS

A series of data is retrieved from Web of Science, PubMed, and Embase databases to observe the association of HRT and knee osteoarthritis up to December 2021. Two separated reviewers chose the research, extracted the data, and evaluated the study quality. Pooled estimates of 95% CI and HRs were acquired through a random-effects model.

RESULTS

Finally, there existed 13 pieces of research, containing one case-control research, four cross-sectional pieces of research, as well as eight cohort pieces of research, involving 2573,164 participants. The overall results showed that the use of HRT was related to a raised risk of knee OA (HR = 1.24, 95% CI 1.07-1.45). And the pooled analysis showed a statistically significant raised risk of knee joint replacement (HR = 1.30, 95% CI 1.09-1.54) when using HRT. In addition, the outcome exhibits the raised knee OA risk for the present users of HRT (HR = 1.40, 95% CI 1.16-1.68) according to HRT status. In the past users of HRT, the augment of knee OA risk was not statistically evident (HR = 1.16, 95% CI 0.94-1.42).

CONCLUSION

We observed that HRT use was related to a raised knee OA risk. Furthermore, future studies might focus on relevant mechanistic to verify our observed associations.

Optimización preoperatoria del paciente antes de una artroplastia de cadera o rodilla: parte 1

Las artroplastias de cadera y rodilla son estrategias que han demostrado ser efectivas en el tratamiento de la patología degenerativa articular. El reemplazo articular mejora la calidad de vida de la mayoría de los pacientes cuando el tratamiento conservador falla. Sin embargo, estas son cirugías mayores que conllevan un riesgo significativo de complicaciones, incluyendo la necesidad de una revisión. El propósito de este artículo es analizar los factores de riesgo modificables del paciente antes de la cirugía, a finde disminuir el riesgo de complicaciones posoperatorias. Estudios recientes han descripto ciertos factores de riesgo modificables, inherentes al paciente y que incrementan la posibilidad de complicaciones posoperatorias luego de un reemplazo articular de cadera o rodilla. Estos incluyen obesidad, malnutrición, tabaquismo, diabetes, anemia, deficiencia de vitamina D, consumo de opioides, artropatías inflamatorias, insuficiencia renal crónica y colonización por estafilococco meticilino-resistente. Si conseguimos optimizar estas condiciones durante el preoperatorio, reduciremos el riesgo de complicaciones posoperatorias.

Does obesity lead to lower rates of clinically meaningful improvement or satisfaction after total hip arthroplasty? A propensity score-matched study

BACKGROUND

Current literature lacks consensus regarding the impact of obesity on clinical outcomes of total hip arthroplasty (THA). The variability of results may reflect the lack of minimal clinically important difference (MCID) analysis, which helps to standardise the interpretation of patient-reported outcome measures (PROMs). We compared the PROMs, patient satisfaction and survivorship between obese and non-obese patients after THA.

METHODS

Prospectively collected registry data of 192 obese patients and 192 propensity score-matched controls who underwent primary THA at a single institution were reviewed. Clinical outcomes and satisfaction rates were assessed at 6 months and 2 years. Reoperations for surgical complications and revision rates were analysed.

RESULTS

Obese patients had a significantly poorer Oxford Hip Score (OHS) at 6 months and WOMAC-Function at 2 years. However, there was no difference in overall WOMAC, WOMAC-Pain, WOMAC-stiffness, SF-36 mental and physical component summary (PCS). A similar proportion of patients in each group achieved the MCID for OHS, WOMAC and SF-36 PCS. At 2 years, 90.3% of obese patients and 91.7% of controls were satisfied (p = 0.755). At a mean follow-up of 9 years, there were 5 reoperations (2.6%) for surgical complications in the obese group and 1 (0.5%) in the control group; whereas 12 revisions (6.3%) were recorded in the obese group and 3 (1.6%) in the control group (p = 0.021).

CONCLUSIONS

Despite a higher revision rate, obese patients undergoing THA may experience a similar level of clinical meaningful improvement and satisfaction as their non-obese counterparts. This study provides valuable prognostic information for obese patients and guides preoperative counselling.

Obesity paradox in joint replacement for osteoarthritis - truth or paradox?

Obesity is associated with an increased risk of cardiovascular disease (CVD) and other adverse health outcomes. In patients with pre-existing heart failure or coronary heart disease, obese individuals have a more favourable prognosis compared to individuals who are of normal weight. This paradoxical relationship between obesity and CVD has been termed the 'obesity paradox'. This phenomenon has also been observed in patients with other cardiovascular conditions and diseases of the respiratory and renal systems. Taking into consideration the well-established relationship between osteoarthritis (OA) and CVD, emerging evidence shows that overweight and obese individuals undergoing total hip or knee replacement for OA have lower mortality risk compared with normal weight individuals, suggesting an obesity paradox. Factors proposed to explain the obesity paradox include the role of cardiorespiratory fitness ("fat but fit"), the increased amount of lean mass in obese people, additional adipose tissue serving as a metabolic reserve, biases such as reverse causation and confounding by smoking, and the co-existence of older age and specific comorbidities such as CVD. A wealth of evidence suggests that higher levels of fitness are accompanied by prolonged life expectancy across all levels of adiposity and that the increased mortality risk attributed to obesity can be attenuated with increased fitness. For patients about to have joint replacement, improving fitness levels through physical activities or exercises that are attractive and feasible, should be a priority if intentional weight loss is unlikely to be achieved.

Malpractice litigation following orthopaedic surgery of the hip: Frequency, reasons for lawsuit, and outcomes

Medical malpractice litigation in the United States has resulted in the widespread adoption of defensive medicine practices. Orthopaedic surgery is among the specialties most likely to face a malpractice lawsuit, and hip-related surgeries are commonly involved. This study aimed to analyse malpractice litigation as it relates to hip surgery in the United States. The purpose of this study was to seek answers to the following questions: Has there been an increase or a decrease in the number of hip surgery malpractice cases in recent years? What are the most common reasons for a patient to pursue litigation? Which surgical complications are most likely to result in a lawsuit? What trends do we see in terms of outcomes? The Westlaw legal database was queried for all relevant cases from 2008 to 2018. A retrospective review of cases was conducted and descriptive analyses were performed in order to identify factors associated with hip surgery malpractice litigation. A total of 82 cases were analysed. There was a downtrend in the number of cases per year. Total hip arthroplasty (47 cases, 57.3%) was the procedure most often involved. Procedural error was noted as a reason for litigation in 71 (86.6%) cases. Neurological injury (22 cases, 26.8%), malpositioned hardware (15 cases, 18.3%) and leg length discrepancy (8 cases, 9.8%) were the most common complications listed. The majority of cases resulted in a verdict in favour of the defendant orthopaedic surgeon (48 cases, 58.5%). The mean payout for a plaintiff verdict (20 cases, 24.4%) was $1,647,981 (range, $1,852-$7,000,000) and the mean payout for a settlement (13 cases, 15.9%) was $657,823 (range, $49,000-$3,000,000) (p = 0.063). The study concluded that, within the 10-year period, there was a significant downtrend in hip surgery malpractice cases filed per year. Orthopaedic surgeons were found liable in the minority of cases. As expected, verdicts in favour of plaintiffs resulted in seemingly higher payouts than settlements.

Retention Stitches: A Concept of Wound Closure of Knee Arthroplasty in Obese Patients

BACKGROUND

Knee joint arthroplasty is a commonly performed procedure. However, number of obese patients undergoing total knee arthroplasty is on a rise. In such cases, post closure using routine techniques, there have been an increasing number of cases of wound dehiscence and complications like persistent discharge and delayed healing. To overcome this problem, the author has come up with an innovative technique in closure.

MATERIALS AND METHODS

27 patients, who were obese, were included in the study and operated at Orthopaedic Arthroscopic Knee and Shoulder clinic. The patients were evaluated pre operatively clinically and planned for retention stitches for closure. Same technique was followed for closure in all the patients. Suture removal was done at 2 weeks and patients were followed up for a period of 6 months for any complications.

RESULTS

In 27 patients undergoing retention stitches post total knee arthroplasty, patients were followed up for a mean period of 14 months, with minimum being 6 months and maximum being 5 years. Patients showed no complications such as wound dehiscence, discharge, localised skin necrosis or cut-through of stitches.

CONCLUSION

Retention stitches in knee arthroplasty is an innovative, ideal, yet easily replicable method of wound closure in obese patients, especially with BMI > 30 (Obesity grade 1 or more). Patients undergo better and uneventful wound healing, which is of paramount importance in a surgery like this. In all these patients, the rehabilitation post surgery is also similar to the other patients, hence not affecting the outcome.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00596-y.

The burden of OA-health services and economics

Osteoarthritis (OA) is a highly prevalent and disabling condition that affects over 7% of people globally (528 million people). Prevalence levels are even higher in countries with established market economies, which have older demographic profiles and a higher prevalence of obesity, such as the US (14%). As the 15th highest cause of years lived with disability (YLDs) worldwide, the burden OA poses to individuals is substantial, characterized by pain, activity limitations, and reduced quality of life. The economic impact of OA, which includes direct and indirect (time) costs, is also substantial, ranging from 1 to 2.5% of gross national product (GNP) in countries with established market economies. In regions around the world, the average annual cost of OA for an individual is estimated between $700-$15,600 (2019 USD). Though trends in OA prevalence vary by geography, the prevalence of OA is projected to rise in regions with established market economies such as North America and Europe, where populations are aging and the prevalence of obesity is rising.

Novel radiographic hip fat thickness ratio correlates with early re-operation following total hip arthroplasty

INTRODUCTION

Obesity is thought to lead to increased failure rates following total hip arthroplasty (THA). Site-specific fat distribution has been suggested to be a better indicator of risk, compared to body mass index. Fat thickness measurement methods were developed for total knee arthroplasty, however, there is limited data on the methods for THA. The aim of this study was to assess the interobserver and intraobserver reliability of a newly defined radiographic subcutaneous fat thickness ratio and investigate the correlation of this ratio with early failure following THA.

METHODS

321 patients who underwent primary THA at a single institution between 2014 and 2017, with at least 1-year of follow-up and a preoperative pelvis anteroposterior x-ray radiograph were included in this study. A high hip fat thickness ratio (HFTR) was arbitrarily defined as ⩾2. Early failure was defined as revision or re-operation for any reason and death related to operation first year following THA.

RESULTS

The HFTR was shown to have excellent intraobserver and interobserver reliability. High HFTR was associated with higher risk of early failure following THA (odds ratio 3.8, [95% confidence interval, 1.2-12.1], p < 0.05). The same association persisted when HFTR was analysed as a continuous variable (p < 0.01) and in multivariate analysis (p < 0.05).

CONCLUSIONS

HFTR can be used to assess periarticular soft tissue distribution and may be regarded as a useful and reproducible tool for assessing risk of early failure following THA.

The Influence of Obesity on Unicompartmental Knee Arthroplasty Outcomes: A Systematic Review And Meta-Analysis

Obesity is associated with a greater prevalence of symptomatic knee osteoarthritis. Obese patients are thought to have worse outcomes following unicompartmental knee arthroplasty (UKA).The aim is to compare clinical and functional outcomes of UKA in obese to non-obese patients. A systematic review on six databases (PubMed, MEDLINE, Embase, Web of Science, Scopus, and CENTRAL) from inception through July 2020 was performed. We extracted data to determine revision risk (all-cause, septic, and aseptic), complication risk, and infection risk, functional outcome scores (Knee Society Score [KSS], Oxford Knee Score [OKS], and range of movement [ROM]) in patients with obesity (BMI >30kg/m2) to non-obese patients (BMI <30kg/m2). Meta-analysis was performed using a random effects model. The MINORS criteria was used for quality assessment. Twelve of 715 studies were eligible. Compared with non-obese patients, obese patients had a higher risk ratio for all-cause revision (RR 1.49; 95% CI 1.04 to 2.13; p = 0.03); aseptic revision (RR 1.36; 95% CI 1.01 to 1.81; p=0.04) and complications (RR 2.12; 95% CI 1.17 to 3.85; p=0.01). No significant differences were found in risk of septic revision and overall infection. Obese patients also had lower KSS scores (MD -3.21; 95% CI -5.52 to -0.89; p<0.01), OKS scores (MD -2.21; 95% CI -3.94 to -0.48; p=0.01), and ROM (MD -7.17; 95% CI -12.31 to -2.03; p<0.01). The average MINORS score was 14.2, indicating a moderate quality of evidence. In conclusion, the risk of revision, aseptic revision, and complications are higher in obese patients. The clinical significance of a lower functional score in obese may not be appreciable. Despite the greater risks, there is no conclusive evidence that obesity should be a contraindication to UKA. Further studies are required to corroborate the current conclusions with higher-quality study designs.

Google trends as a tool for evaluating public interest in total knee arthroplasty and total hip arthroplasty

BACKGROUND AND AIMS

There are approximately 1 million total knee arthroplasty (TKA) and total hip arthroplasty (THA) procedures performed annually in the United States. With this number projected to increase, it is vital for orthopedic surgeons and health-care systems to properly anticipate healthcare utilization related to TKA and THA. Google Trends (GT) is a free, open source tool that provides customizable analysis of search terms entered into the Google search engine. We aim to explore the relationship between public interest in TKA and THA as determined by GT data and volume of TKA and THA procedures.

METHODS

GT data were compiled for ten search terms related to TKA and ten search terms related to THA from January 2009 to December 2017. Annual case volumes for TKA/THA procedures were obtained from the Healthcare Cost and Utilization Project National Inpatient Sample from 2009 to 2017. Trend analysis was performed using univariate linear regression of GT data and TKA/THA case volumes.

RESULTS

There was a statistically significant positive correlation between GT data and procedure volume for 14 of the 20 search terms studied. Seven TKA-related search terms with a positive correlation to procedure volumes include "total knee replacement," "knee replacement," "knee osteoarthritis," "knee ache," "knee swelling," "knee stiffness," and "chronic knee pain." Seven THA-related search terms with a positive correlation to procedure volumes include "hip arthroplasty," "total hip replacement," "hip replacement," "hip osteoarthritis," "hip ache," "hip swelling," and "chronic hip pain."

CONCLUSION

GT may provide a high utility as a convenient and informative data set for orthopedic surgeons to analyze public interest in TKA and THA procedures. The data provided by GT have the potential to provide real-time, actionable information that may help surgeons and health systems to characterize public interest in TKA and THA and to best identify and address patient needs.

RELEVANCE FOR PATIENTS

The GT tool can be used to measure public interest in TKA/THA, which can inform physician expectations for the patient encounter and lead to the creation of decision aids that better inform the public about the risks and benefits of TKA/THA.

Early Postoperative Pain After Total Knee Arthroplasty Is Associated With Subsequent Poorer Functional Outcomes and Lower Satisfaction

BACKGROUND

There are few studies investigating the effects of acute postoperative pain on functional outcomes after total knee arthroplasty (TKA). The aims of this study are to identify perioperative factors associated with increased early postoperative pain and investigate the effects of acute postoperative day 1 and 2 pain on outcomes at 6 months and 2 years post-TKA.

METHODS

1041 unilateral TKA patients were included in this retrospective cohort study. Patients were categorized into minor (visual analog scale: VAS <5) and major (VAS ≥5) pain groups based on postoperative day 1/2 VAS scores. Patients were assessed preoperatively, at 6 months and 2 years using Knee Society Knee Score and Function Scores (KSFS), Oxford Knee Score (OKS), SF-36 physical and mental component score (SF-36 PCS), expectation and satisfaction scores. Perioperative variables including age, gender, race, body mass index, American Society of Anesthesiologist status, type of anesthesia, and presence of caregiver were analyzed as predictors of postoperative acute pain. Wilcoxon two-sample test was used to analyze outcomes significantly associated with "major pain." Multiple logistic regression was used to identify predictors of "major pain."

RESULTS

Patients with "minor pain" had significantly better KSFS, Knee Society Knee Score, OKS, and SF-36 PCS scores at 6 months and significantly better KSFS, OKS, SF-36 PCS, and satisfaction at 2 years (P < .05). A significantly higher percentage of patients with "minor pain" met the minimal clinically important difference for SF-36 PCS at 6 months and KSFS at 2 years (P < .05). Women, Indian/Malay race, higher BMI, and use of general over regional anesthesia were independent predictors of getting "major pain" (P < .05).

CONCLUSION

Patients should be counseled about risk factors of postoperative pain to manage preoperative expectations of surgery. Patients should be managed adequately using multimodal pain protocols to improve subsequent functional outcomes while avoiding unnecessary opioid use.

Influence of HRGO Nanoplatelets on Behaviour and Processing of PMMA Bone Cement for Surgery

Bone cement, frequently based on poly (methyl methacrylate), is commonly used in different arthroplasty surgical procedures and its use is essential for prosthesis fixation. However, its manufacturing process reaches high temperatures (up to 120 °C), producing necrosis in the patients’ surrounding tissues. To help avoid this problem, the addition of graphene could delay the polymerisation of the methyl methacrylate as it could, simultaneously, favour the optimisation of the composite material’s properties. In this work, we address the effect of different percentages of highly reduced graphene oxide with different wt.% (0.10, 0.50, and 1.00) and surface densities (150, 300, 500, and 750 m²/g) on the physical, mechanical, and thermal properties of commercial poly (methyl methacrylate)-based bone cement and its processing. It was noted that a lower sintering temperature was achieved with this addition, making it less harmful to use in surgery and reducing its adverse effects. In contrast, the variation of the density of the materials did not introduce significant changes, which indicates that the addition of highly reduced graphene oxide would not significantly increase bone porosity. Lastly, the mechanical properties (strength, elastic modulus, and fracture toughness) were reduced by almost 20%. Nevertheless, their typical values are high enough that these new materials could still fulfil their structural function. In conclusion, this paper presents a way to control the sintering temperature, without significant degradation of the mechanical performance, by adding highly reduced graphene oxide so that local necrosis of bone cement based on poly (methyl methacrylate) used in surgery is avoided.

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

BACKGROUND

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

AIM

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

METHODS

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

FINDINGS

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

CONCLUSION

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

Functional Evaluation and Pain Symptomatology of the Foot and Ankle in Individuals with Severe Obesity - Controlled Transversal Study

Objective  The present study aims to evaluate the prevalence of foot and ankle pain complaints, radiographic parameters, and functional performance in subjects with severe obesity (body mass index [BMI] > 40) who are candidates to bariatric surgery.

Methods  Forty severely obese patients were evaluated at a bariatric surgery outpatient facility. These severely obese subjects (BMI > 40) were divided into two subgroups: those with BMI < 50 (n = 24) and BMI > 50 (n = 16). These patients were compared with a control group of 42 volunteers with a mean BMI value of 24. The following parameters were assessed: foot pain (according to the visual analog scale [VAS]), functional performance (according to the American Orthopeadic Foot and Ankle Society [AOFAS] scale, including forefoot, midfoot and hindfoot domains), age, gender, hallux metatarsal-phalangeal angle, hallux intermetatarsal angle, talocalcaneal angle, calcanean pitch angle and Meary angle.

Results  Incidence of foot pain was higher in the severely obese group compared with the control group ( p  < 0.0001; odds ratio [OR]: 4.2). Functional performance according to the AOFAS scale was lower in obese subjects compared with the control group ( p  < 0.0001; OR for hindfoot, 4.81; OR for midfoot, 3.33).

Conclusion  The incidence of foot pain was higher in the group of severely obese patients compared with the control group. According to the AOFAS scale, functional forefoot, midfoot and hindfoot performance was worse in severely obese individuals.

Medications Available for Weight Reduction in Elective Total Joint Arthroplasty

Arthroplasty in patients with elevated body mass index results in increased rates of reoperation, instability, revision, and infection. Preoperative weight loss may reduce the complication rate associated with orthopaedic surgery. In addition to lifestyle modification, anti-obesity medications are available to help patients to reduce their preoperative weight. Currently, there are 6 U.S. Food and Drug Administration (FDA)-approved anti-obesity medications in the United States: phentermine, orlistat, phentermine with topiramate extended release (ER), lorcaserin, sustained release (SR) naltrexone with bupropion, and liraglutide. Anti-obesity medications potentially provide a new way to optimize patients before surgery and to ensure successful recovery postoperatively.

Preoperative communication between anaesthetists and patients with obesity regarding perioperative risks and weight management: a structured narrative review

BACKGROUND

Individuals with obesity frequently present for anaesthesia and surgery. Good communication during the preoperative consultation can optimise the provision of relevant health information and guide improvement of health status preoperatively.

METHODS

We planned a systematic literature review to assess existing guidelines and evidence of effectiveness for how anaesthetists should communicate with patients who have obesity in the preoperative period about perioperative risks and weight management. Database searches used keywords related to perioperative weight loss conversations. We found no papers that directly addressed our aim. The literature identified as most relevant was analysed in the form of a narrative review.

RESULTS

The majority of suggestions for weight loss conversations came from primary care. Four primary themes potentially relevant to anaesthetists were identified: barriers to such conversations, communication tools, language and communication and specific recommendations. Identified barriers included lack of skills, training, poor remuneration, pessimism and time constraints for clinicians. Established discussion tools including the '5A's' approach (Assess, Advise, Agree, Assist, Arrange) and motivational interviewing may hold promise to improve preoperative conversations. The papers highlighted a need for empathetic language, including use of patient-specific language where possible.

CONCLUSIONS

There are currently no published guidelines for how anaesthetists could most effectively discuss weight in the perioperative period with patients who have obesity. Much of the literature for obesity communication is based on the primary care setting. The perioperative period may represent an increased time of receptiveness for patients. Guidelines for discussions about weight management and associated perioperative risk are suggested.

Increase in Tryptase and Its Role in the Synovial Membrane of Overweight and Obese Patients with Osteoarthritis of the Knee

PURPOSE

The mechanisms governing evidence that obesity is a risk factor for osteoarthritis (OA) are not well understood. We previously reported an increase in mast cell (MC) marker expression in the osteoarthritic synovial membrane (SM) of patients with obesity. We hypothesized that an enzyme produced by MC, β-tryptase, may be increased in the SM of obese patients with knee OA and contribute to synovial inflammation. This study investigated the expression of the β-tryptase encoding gene, TPSB2, in the SM of obese patients with knee OA and β-tryptase-mediated regulation of IL-1β in synovial cells.

PATIENTS AND METHODS

A total of 216 patients radiographically diagnosed with knee OA were grouped according to the World Health Organization's body mass index classifications: normal weight (NW; <25 kg/m²), overweight (OW; 25-29.99 kg/m²) and obese (OB; ≥30 kg/m²). Quantitative polymerase chain reaction was conducted to examine TPSB2 expression in the SM among the three groups. We also examined TPSB2 and IL1B expression in MC-rich (CD3-CD14-CD19-CD90-) and MC-poor (CD3+, CD14+, CD19+, or CD90+) fractions freshly isolated from synovial tissue. Further, the effect of β-tryptase on IL1B expression was investigated in cultured CD14-positive (macrophage-rich fraction) and CD14-negative (fibroblast-rich fraction) cells.

RESULTS

There was significantly elevated TPSB2 expression in the OW and OB groups compared to the NW group. The MC-rich fraction had significantly higher levels of TPSB2, CD117 and CD203c than the MC-poor fraction. Recombinant human β-tryptase stimulated IL1B expression in both the synovial fibroblast and macrophage fractions.

CONCLUSION

Obese patients with knee OA showed elevated TPSB2 expression in the SM. Tryptase may play a role in synovial inflammation in obese patients with OA.

Twenty-year survivorship of a cemented mobile bearing Total Knee Arthroplasty

BACKGROUND

Increasing numbers of Total Knee Arthroplasty (TKA) operations are carried out worldwide each year. This brings with it an ever-increasing revision burden and it is therefore important to appreciate both the functional outcome and survivorship of established arthroplasties when considering new designs. We aim to evaluate the long-term survivorship of a fully cemented mobile bearing Total Knee Arthroplasty.

METHODS

This study prospectively analyses the 20-year survivorship of a cohort of 487 consecutive patients who underwent cemented TKA under the care of a single surgeon using the Low Contact Stress (LCS) rotating platform (RP) implant. These patients were followed up prospectively with patient reported and functional outcomes recorded at regular intervals postoperatively.

RESULTS

Five hundred and forty-two consecutive primary TKAs were carried out in 487 patients. A total of 139 knees (25.6%) were reviewed at 20 years post-operation. Overall cumulative survivorship, using revision for any reason as primary endpoint, was 98.0%. Mean Knee Society Scores for the patient cohort were 87.3 (Clinical score) and 52.5 (Functional score). Eleven (2.0%) were revised within 20 years - two for aseptic loosening, two for unexplained pain, five secondary patellar resurfacings for anterior knee pain, one for late infection and one liner exchange following spin-out.

CONCLUSION

This series demonstrates excellent survivorship and satisfactory outcome of a cemented mobile bearing TKA at 20 years.

Body mass index is associated with risk of reoperation and revision after primary total hip arthroplasty: a study of the Swedish Hip Arthroplasty Register including 83,146 patients

Background and purpose - The prevalence of obesity is on the rise, becoming a worldwide epidemic. The main purpose of this register-based observational study was to investigate whether different BMI classes are associated with increased risk of reoperation within 2 years, risk of revision within 5 years, and the risk of dying within 90 days after primary total hip arthroplasty (THA). We hypothesized that increasing BMI would increase these risks. Patients and methods - We analyzed a cohort of 83,146 patients who had undergone an elective THA for primary osteoarthritis between 2008 and 2015 from the Swedish Hip Arthroplasty Register (SHAR). BMI was classified according to the World Health Organization (WHO) into 6 classes: < 18.5 as underweight, 18.5-24.9 as normal weight, 25-29.9 as overweight, 30-34.9 as class I obesity, 35-39.9 as class II obesity, and ≥ 40 as class III obesity. Results - Both unadjusted and adjusted parameter estimates showed increasing risk of reoperation at 2 years and revision at 5 years with each overweight and obesity class, mainly due to increased risk of infection. Uncemented and reversed hybrid fixations and surgical approaches other than the posterior were all associated with increased risk. Obesity class III (≥ 40), male sex, and increasing ASA class were associated with increased 90-day mortality. Interpretation - Increasing BMI was associated with 2-year reoperation and 5-year revision risks after primary THA where obese patients have a higher risk than overweight or normal weight patients. As infection seems to be the main cause, customizing preoperative optimization and prophylactic measures for obese patients may help reduce risk.

Impact of body mass index on utilization of selected hospital resources for four common surgical procedures

BACKGROUND

Evidence about the impact of obesity on surgical resource consumption in the Australian setting is equivocal. Our objectives were to quantify the prevalence of obesity in four frequently performed surgical procedures and explore the association between body mass index (BMI) and hospital resource utilization including procedural duration, length of stay (LOS) and costs.

METHODS

A retrospective cohort study of patients undergoing four surgical procedures at a tertiary referral centre in New South Wales, between 1 January 2016 and 31 December 2016, was conducted. The four surgical procedures were total hip replacement, laparoscopic appendectomy, laparoscopic cholecystectomy and hysteroscopy with dilatation and curettage. Surgical groups were stratified according to BMI category.

RESULTS

A total of 699 patients were included in the study. The prevalence of obesity was significantly higher than local and national population estimates for all procedures except appendectomy. BMI was not associated with increased hospital resource utilization (procedural, anaesthetic or intensive care stay duration) in any of the four surgical procedures examined after controlling for age, gender and complexity. For other outcomes of hospital resource utilization (LOS and cost), the relationship was inconsistent across the four procedures examined. A high BMI was positively associated with higher LOS, medical costs and allied health costs in those who underwent an appendectomy, and critical care costs in those who underwent laparoscopic cholecystectomy.

CONCLUSION

Obesity was common in patients undergoing four frequently performed surgical procedures. The relationship between BMI and hospital resource utilization appears to be complex and varies across the four procedures examined.

Redesign of a continuous passive motion machine for total knee replacement therapy

Purpose

After knee replacement surgery, rehabilitation is needed to recover to normal levels of mobility. A continuous passive motion (CPM) machine is usually introduced at this stage to aid rehabilitation. However, the redundant structure and complex mechanism of the existing machine has resulted in irregular use. The purpose of this paper is to redesign the current machine.

Design/methodology/approach

The mechanical and electrical systems of the current machine were studied alongside interviews with stakeholders. Problems with the existing machine were identified. Related information was gathered in both the engineering and medical aspects. The redesign concept of the equipment was specified following engineering analyses to develop the final model. Finite element analysis was performed to ensure the appropriate size and dimension of the equipment. The prototype of the redesigned CPM was manufactured in-house. Product testing was conducted with 40 volunteers including experienced therapists, nurses, university students and working-age people.

Findings

Compared to the previous machine, the newly designed model was improved in both functioning and manufacturing costs. The redesigned machine is more durable and consists of a less complex structure.

Originality/value

The redesigned machine introduces some new features and removes unnecessary functions. As a result, the model costs less and hence, is considered beneficial to the general public. More utilization is expected which could eventually reduce the therapists’ workload at the hospital. This research provides well-defined processes of the product development starting from the users’ requirement analysis to the prototype testing stage.

Leptin Increases Particle-Induced Osteolysis in Female ob/ob Mice

Particles generated from wear of prosthesis joint bearing surfaces induce inflammation-mediated periprosthetic bone resorption (osteolysis). Morbidly obese leptin-deficient ob/ob mice are resistant to polyethylene particle-induced bone loss, suggesting that leptin, a hormone produced by adipocytes that circulates in concentrations proportional to total body adiposity, increases osteolysis. To confirm that particles induce less osteolysis in leptin-deficient mice after controlling for cold stress (room temperature)-induced bone loss, ob/ob mice on a C57BL/6 (B6) background and colony B6 wildtype (WT) mice housed at thermoneutral temperature were randomized to control or particle treatment groups (N = 5/group). Polyethylene particles were implanted over calvaria and mice sacrificed 2 weeks later. Compared to particle-treated WT mice, particle-treated ob/ob mice had lower osteolysis score, less infiltration of immune cells, and less woven bone formation. To determine the role of leptin in particle-induced osteolysis, ob/ob mice were randomized into one of 4 groups (n = 6-8/group): (1) control, (2) particles, (3) particles + continuous leptin (osmotic pump, 6 μg/d), or (4) particles + intermittent leptin (daily injection, 40 μg/d). Leptin treatment increased particle-induced osteolysis in ob/ob mice, providing evidence that the adpiokine may play a role in inflammation-driven bone loss. Additional research is required to determine whether altering leptin levels within the physiological range results in corresponding changes in polyethylene-particle-induced osteolysis.

Total hip arthroplasty outcomes in morbidly obese patients: A systematic review

The increasing prevalence of obesity has resulted in a marked increase in the number of total hip arthroplasties (THAs) carried out in patients with a high body mass index (BMI).

THA in morbidly obese patients is often technically challenging owing to the associated co-morbidities and anatomical factors. Furthermore, the long-term clinical and functional outcomes of the procedure in these patients are not clear.

The aim of this systematic review was to compare the long-term failure rate and functional outcomes of THA in morbidly obese versus non-obese patients.

A literature search of PubMed, EMBASE and PubMed Central was conducted to identify studies that compared the outcomes of THA in patients defined as morbidly obese (BMI ≥ 35) to a control group (BMI < 30). The primary and secondary outcome measures were rate of revision and functional outcome, respectively, in the long term.

Eight studies were included in this review. There were 66,238 THAs in morbidly obese patients and 705,619 THAs in patients with a BMI < 30. The overall revision rate was 7.99% in the morbidly obese patients versus 2.75% in the non-obese controls. The functional outcome was at least comparable to non-obese patients.

This review suggests that morbidly obese patients have a slightly increased revision rate following THA. Importantly, these patients have a functional recovery at least comparable to those with a BMI < 30. Morbidly obese patients should be fully informed of these issues prior to undergoing surgery.

Cite this article: EFORT Open Rev 2018;3:507-512. DOI: 10.1302/2058-5241.3.180011

Radiographic evaluation and pain symptomatology of the knee in severely obese individuals - controlled transversal study

Objective

To evaluate the prevalence of pain and radiographic degenerative arthritis in a group of severe obese patients (body mass index [BMI] > 35).

Methods

41 patients with an indication of bariatric surgery were studied. The group of severely obese patients was subdivided into two subgroups: those with BMI < 50 and those with BMI > 50 (n = 14). They were compared to control group (n = 39). The following parameters were analyzed and correlated: radiographic arthritis by Kellgren-Lawrence's classification, tibiofemoral axis, gender, age, and knee pain (visual analog scale [VAS]). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to evaluate in 21 severe obese patients and IN 19 controls.

Results

A higher incidence of knee pain was observed in the severely obese group when compared with the control group (p < 0.0001, odds ratio: 2.96). In the severely obese group, increasing levels of pain with aging were observed (p = 0.047). A positive correlation was observed between the incidence of radiographic arthritis and increasing age in the severely obese (p = 0.001) and control (p = 0.037) groups. The WOMAC index results were worse in the severely obese group when compared with the control group (p = 0.001, odds ratio: 18.2).

Conclusion

A higher incidence of knee pain was observed in the severely obese group when compared with the control group. In the severely obese group, there increasing levels of pain with aging. A positive relation between the incidence of arthritis and increasing age was observed in the severely obese and control groups. The WOMAC index results were worse in the severely obese group.

Body Mass Index Class Is Independently Associated With Health-Related Quality of Life After Primary Total Hip Arthroplasty: An Institutional Registry-Based Study

BACKGROUND

The purpose of this study was to compare the health-related quality of life (HRQoL) of patients across World Health Organization (WHO) body mass index (BMI) classes before and after total hip arthroplasty (THA).

METHODS

Patients with end-stage hip osteoarthritis who received elective primary unilateral THA were identified through an institutional registry and categorized based on the World Health Organization BMI classification. Age, sex, laterality, year of surgery, and Charlson-Deyo comorbidity index were recorded. The primary outcome was the EQ-5D-3L index and visual analog scale (EQ-VAS) scores at 2 years postoperatively. Inferential statistics and regression analyses were performed to determine associations between BMI classes and HRQoL.

RESULTS

EQ-5D-3L scores at baseline and at 2 years were statistically different across BMI classes, with higher EQ-VAS and index scores in patients with lower BMI. There was no difference observed for the 2-year change in EQ-VAS scores, but there was a statistically greater increase in index scores for more obese patients. In the regression analyses, there were statistically significant negative effect estimates for EQ-VAS and index scores associated with increasing BMI class.

CONCLUSION

BMI class is independently associated with lower HRQoL scores 2 years after primary THA. While absolute scores in obese patients were lower than in nonobese patients, obese patients enjoyed more positive changes in EQ-5D index scores after THA. These results may provide the most detailed information on how BMI influences HRQoL before and after THA, and they are relevant to future economic decision analyses on the topic.

The Effect of Medical Marijuana Laws on Body Weight

This study is the first to examine the effects of medical marijuana laws (MMLs) on body weight, physical wellness, and exercise. Using data from the 1990 to 2012 Behavioral Risk Factor Surveillance System and a difference-in-difference approach, we find that the enforcement of MMLs is associated with a 2% to 6% decline in the probability of obesity. We find some evidence of age-specific heterogeneity in mechanisms. For older individuals, MML-induced increases in physical mobility may be a relatively important channel, while for younger individuals, a reduction in consumption of alcohol, a substitute for marijuana, appears more important. These findings are consistent with the hypothesis that MMLs may be more likely to induce marijuana use for health-related reasons among older individuals, and cause substitution toward lower-calorie recreational 'highs' among younger individuals. Our estimates suggest that MMLs induce a $58 to $115 per-person annual reduction in obesity-related medical costs. Copyright © 2015 John Wiley & Sons, Ltd.

Does obesity influence early outcome of fixed-bearing unicompartmental knee arthroplasty?

Obesity is a known major contributing risk factor for knee osteoarthritis (OA). It is also believed that obese unicompartmental knee arthroplasty (UKA) patients tend to have poorer outcome and possible early failure. The purpose of this study is to investigate the early outcome of obese UKA patients in a single institution. Patients who underwent fixed bearing medial UKA in between year 2005 and 2010 were included in this study. They were divided into four groups based on Body Mass Index (BMI): 25 kg/m² (Control); 25-29.9 kg/m² (Overweight); 30-34.9 kg/m² (Obese); >35 kg/m² (Severely Obese). Functional outcome was assessed using Knee Society Score (KSS), Oxford Knee Score (OKS) and Short-form 36 (SF-36). One-way ANOVA with Bonferroni post-hoc test was used to compare the four groups for quantitative variables. There were 673 patients in this study, no significant difference between the four BMI groups for gender and side of operated knee ( p > 0.05). The functional outcome of all four groups at 2 years were comparable (all p > 0.05). At a mean follow up of 5.4 (range 2.5, 8.5) years, 9 revision surgeries (1.3%) were identified. The mean duration from initial surgery to revision surgery was 49 months (Range 6, 90). Patients' pre-operative BMI did not influence the early outcome of UKA patients. However, patients with higher BMI had relatively lower functional score prior to the surgery and tended to be younger. This did not translate to early failure and the functional improvement was similar among all four groups.

Is Total Knee Replacement Justified in the Morbidly Obese? A Systematic Review

Total knee replacement (TKR) comprises a significant, growing aspect in the management of patients with advanced arthritis of the knee for which conservative medical therapy has failed. Obesity, a rising epidemic, is considered an important independent risk factor in the development of osteoarthritis (OA). An aging population and increasing incidence of obesity contribute to a higher prevalence of OA and a subsequent greater need for TKR. The numbers of morbidly obese (MO) people undergoing TKR has consistently been rising. However, there have been concerns among patients and surgeons about the outcomes and complications of TKR in MO patients, especially given the morbidities associated with obesity. The goal of this systematic review was to assess relevant, up-to-date data on the safety, outcomes, and complications associated with TKR in MO patients.

A single-centre study of haemostatic outcomes of joint replacement in von Willebrand disease and control patients and an analysis of the literature

INTRODUCTION

Haemostatic assessments of patients with von Willebrand disease (VWD) who undergo total knee arthroplasty (TKA) and total hip arthroplasty (THA) have mainly relied on subjective parameters.

AIMS

To compare objective haemostatic outcomes of TKA/THA in VWD patients and controls without bleeding disorders.

METHODS

We retrospectively analysed haemostatic outcomes in VWD patients undergoing TKA/THA from 1993 to 2011 and compared them with two matched controls per operation. Using one-way analysis of variance, we tested the effect of VWD on bleeding risk after TKA and THA.

RESULTS

Twelve VWD patients (6 type 1, 3 type 2M, 1 each of types 2A/2B/3) undergoing 19 operations (12 TKA, 7 THA) were matched to 38 controls. One (5%) of 19 operations in VWD patients and none of the control operations met clinical criteria for major bleeding. Baseline and postoperative day 1 haemoglobin levels, postoperative blood loss, transfused red blood cells (RBCs) and mean hospitalization days were not significantly different. More VWD patients than controls received RBC transfusions [12 (63%) vs. 12 (32%)]. Only 9 (47%) VWD patients vs. 38 (100%) controls received pharmacologic VTE prophylaxis. No postoperative symptomatic VTE occurred in either group.

CONCLUSION

In this largest, single-institutional study, von Willebrand factor replacement based on daily levels resulted in low frequency of major bleeding in VWD patients after TKA/THA. RBC transfusion was more frequent compared with matched controls, but other objective measures of haemostasis were similar. Lack of sufficient details in published reports precluded comparison of haemostatic outcomes.

[Total hip arthroplasty in overweight osteoarthritis patients]

BACKGROUND

An increasing number of patients scheduled for total hip arthroplasty (THA) are obese and exhibit a different risk profile from that of patients of normal weight.

OBJECTIVES

To provide an overview of the impact of obesity on the outcome of primary THA.

MATERIALS AND METHODS

Literature review and discussion of own epidemiological data.

RESULTS

Obese patients can expect as much functional improvement as non-obese patients after THA. However, peri- and postoperative complication (e.g., periprosthetic infection and dislocation) rates are reported to be increased in obese THA patients.

CONCLUSIONS

The knowledge of obesity-associated risks is the prerequiste for successful THA in obese patients.

The obese patient

Obesity is a worldwide epidemic that has both economic and health implications of enormous consequence. The obese patients tend to have earlier symptoms related to osteoarthritis, more peri-operative medical problems, higher rates of infection and more technical difficulties intra-operatively following hip and knee arthroplasty. Nevertheless, these patients have good long-term clinical outcomes and implant survival rates and are often some of the most satisfied patients after joint arthroplasty. Therefore, obese patients should not be denied surgery based on their weight alone.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):3–5.

Characterisation of osteoarthritis in a small animal model of type 2 diabetes mellitus

Objectives

Our objective in this article is to test the hypothesis that type 2 diabetes mellitus (T2DM) is a factor in the onset and progression of osteoarthritis, and to characterise the quality of the articular cartilage in an appropriate rat model.

Methods

T2DM rats were obtained from the UC Davis group and compared with control Lewis rats. The diabetic rats were sacrificed at ages from six to 12 months, while control rats were sacrificed at six months only. Osteoarthritis severity was determined via histology in four knee quadrants using the OARSI scoring guide. Immunohistochemical staining was also performed as a secondary form of osteoarthritic analysis.

Results

T2DM rats had higher mean osteoarthritis scores than the control rats in each of the four areas that were analysed. However, only the results at the medial and lateral femur and medial tibia were significant. Cysts were also found in T2DM rats at the junction of the articular cartilage and subchondral bone. Immunohistochemical analysis does not show an increase in collagen II between control and T2DM rats. Mass comparisons also showed a significant relationship between mass and osteoarthritis score.

Conclusions

T2DM was found to cause global degeneration in the UCD rat knee joints, suggesting that diabetes itself is a factor in the onset and progression of osteoarthritis. The immunohistochemistry stains showed little to no change in collagen II degeneration between T2DM and control rats. Overall, it seems that the animal model used is pertinent to future studies of T2DM in the development and progression of osteoarthritis.

Cite this article: Bone Joint Res 2014;3:203–11

Changes in bone mineral density of the distal femur after total knee arthroplasty: a 7-year DEXA follow-up comparing results between obese and nonobese patients

BACKGROUND AND PURPOSE

Periprosthetic femoral bone mineral density (BMD, g/cm2) decreases after total knee arthroplasty (TKA) as a result of the stress-shielding phenomenon. It is not known whether obesity has an effect on this phenomenon or not. The aim of this study was to assess long-term periprosthetic BMD changes after TKA and compare whether there is a difference between obese and nonobese patients.

METHODS

A total of 69 TKAs in 61 patients were performed, and BMD measurements of the distal femur were followed up to 7 years postoperatively. The patients were divided into two study groups according to their body mass index, and the groups were compared in relation to BMD and functional outcome.

RESULTS

The mean of periprosthetic bone loss during the 7-year follow-up varied from 10.3% to 30.6% depending on the region of interest (p<0.0005). The highest bone-loss rates were detected during the first three postoperative months. A total of 26 patients were categorized as obese with a body mass index value of ≥30 kg/m2. The obese patients' total periprosthetic BMD was higher at both baseline (8.6%) and 7 years after operation (p=0.05) (15.2%).

CONCLUSION

Periprosthetic bone loss around the femoral component continued for up to 7 years postoperatively. The loss of bone density was not associated with any negative clinical outcome in this study, but periprosthetic bone loss was of a smaller quantity in the obese which is probably due to higher weight induced stresses on bone.

Rhabdomyolysis is a Potential Complication of Total Hip Arthroplasty in the Morbidly Obese

Rhabdomyolysis (RML) can complicate prolonged surgery and may lead to renal failure and death. Obese patients are at high risk for this complication. This complication has been recently described in bariatric surgery and prolonged spine surgery, but it is not well recognized in patients undergoing THA. We present an obese patient (BMI = 50) who developed RML and acute kidney injury after a total hip arthroplasty.

Musculoskeletal function following bariatric surgery

OBJECTIVE

Bariatric surgery is an effective method for acute weight loss. While the impact of bariatric surgery on general medical conditions (e.g., type 2 diabetes) is well documented, few studies focus on physical functional outcomes following weight-loss induced by bariatric surgery.

DESIGN AND METHODS

We report on 50 women aged 20-74 scheduled for Roux-en-Y gastric bypass (RYGB) procedure who were enrolled for a prospective 1-year study. Height, weight, and waist circumference were recorded preoperatively and at 6 and 12 months, postoperatively. To track musculoskeletal/physical function changes, the timed-get-up-and-go (TGUG) and short-form health survey-36 (SF-36) and short musculoskeletal function assessment (SFMA) questionnaires were administered.

RESULTS

Patients had significant weight loss and functional improvement. At 1 year mean weight loss was 48.5 kg and mean TGUG improvement was 3.1 s. SMFA and SF-36 also showed improvement in functional components with weight loss at 6 months and 1-year post surgery. Significant associations were observed between TGUG and SMFA measures at all time points. Final weight at 1 year post bariatric surgery was also significantly correlated with most functional outcomes and changes in these outcomes. Partial correlations controlling for age revealed additional associations between body weight and functional outcomes, especially at the 6-month visit.

CONCLUSION

Our results suggest that significant rapid weight loss, such as that attained by bariatric surgery, acutely improves musculoskeletal function in morbidly obese patients. Additionally, for patients with musculoskeletal disease or injury, weight loss resulting from bariatric surgery may serve as an adjunct for improving global functional outcome, and enhancing the rehabilitation potential.

Knee laxity after staircase exercise predicts radiographic disease progression in medial compartment knee osteoarthritis

OBJECTIVE

To evaluate whether increased laxity of the knee during daily physical activities such as stair climbing is associated with progression of knee joint osteoarthritis (OA).

METHODS

During the years 2001-2003, 136 patients with bilateral primary medial compartment knee joint OA were enrolled in this prospective study. Baseline data collected were body mass index (BMI), muscle power, radiographic joint space width, mechanical axis on standing radiography, and anteroposterior (AP) knee laxity before and after physical exercise. After 8 years of followup, 84 patients were reexamined to assess radiographic changes. Radiographic disease progression was defined as progression of >1 grade on the Kellgren/Lawrence scale.

RESULTS

AP knee laxity increased significantly after stair climbing. Patients with OA progression and those without progression did not differ significantly in age, sex, baseline quadriceps muscle strength, mechanical axis, joint space width, and AP knee laxity before exercise. The 2 groups of patients did, however, differ significantly in baseline BMI and change in AP knee laxity due to exercise. The risk of progression of knee OA increased 4.15-fold with each millimeter of increase in the change in AP knee laxity due to exercise and 1.24-fold with each point increase in the BMI.

CONCLUSION

Our results indicate that patients with OA progression have significantly greater changes in knee joint laxity during physical activities and a higher BMI than patients without OA progression. These findings suggest that larger changes in knee laxity during repetitive physical activities and a higher BMI play significant roles in the progression of knee OA.

The influence of obesity on total joint arthroplasty

Obesity is an epidemic across both the developed and developing nations that is possibly the most important current public health factor affecting the morbidity and mortality of the global population. Obese patients have the potential to pose several challenges for arthroplasty surgeons from the standpoint of the influence obesity has on osteoarthritic symptoms, their peri-operative medical management, the increased intra-operative technical demands on the surgeon, the intra- and post-operative complications, the long term outcomes of total hip and knee arthroplasty. Also, there is no consensus on the role the arthroplasty surgeon should have in facilitating weight loss for these patients, nor whether obesity should affect the access to arthroplasty procedures.