Should isolated morbid obesity influence the decision to operate in hip and knee arthroplasty?

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Global and local fat effects on bone mass and quality in obesity

Aims

The aim of this study was to investigate the global and local impact of fat on bone in obesity by using the diet-induced obese (DIO) mouse model.

Methods

In this study, we generated a diet-induced mouse model of obesity to conduct lipidomic and 3D imaging assessments of bone marrow fat, and evaluated the correlated bone adaptation indices and bone mechanical properties.

Results

Our results indicated that bone mass was reduced and bone mechanical properties were impaired in DIO mice. Lipidomic sequencing and bioinformatic analysis identified 373 differential lipids, 176 of which were upregulated and 197 downregulated. Functional enrichment analysis revealed a significant downregulation of the pathways: fat digestion and absorption (ko04975) and lipolysis regulation in adipocytes (ko04923) in DIO mice, leading to local fat accumulation. The use of 3D imaging confirmed the increase in fat accumulation within the bone marrow cavity of obese mice.

Conclusion

Our study sheds light on the intricate interplay between fat and bone, and provides a non-toxic and non-invasive method for measuring marrow adipose tissue.

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.

Effect of body mass index on symptomatic venous thromboembolism and prosthesis revision risk after total knee arthroplasty: a long-term study from China

OBJECTIVE

To investigate the effect of body mass index (BMI) on the risk of symptomatic VTE and prosthesis revision after total knee arthroplasty (TKA).

METHODS

Seven thousand one hundred eighty-two patients with primary unilateral TKA treated in our hospital from 2011 to 2020 were divided into four groups according to BMI: BMI < 25 kg/m², BMI 25 kg/m²-29.9 kg/m², BMI 30 kg/m²-34.9 kg/m² and BMI ≥ 35 kg/m². Incidence, Odds ratio and Kaplan-Meier survival analysis were used to evaluate the effects of BMI on symptomatic VTE and prosthesis revision risk after TKA.

RESULTS

The incidence of VTE after TKA was 8.9‰(64/7182). There was no significant difference in the incidence of VTE among different BMI groups(P = 0.452). Deep vein thrombosis mainly occurred in the distal lower extremities, especially in intermuscular veins. Revision rate of prosthesis after TKA was 6.4‰(46/7182). There was no significant difference in revision rate among different BMI groups(P = 0.718). In the univariate analysis of TKA, compared with patients with normal BMI, the risk of postoperative VTE and prosthesis revision in patients with overweight, obesity class I and obesity class II did not increase. Higher prosthesis revision rate and lower prosthesis survival rate were observed in BMI ≥ 35 kg/m² group, although the difference was not statistically significant.

CONCLUSIONS

Through such a retrospective large sample data of long-term follow-up, we believe that the higher BMI was not associated with the increased risk of symptomatic VTE and prosthesis revision after TKA. When TKA was used for appropriate indications, high BMI should not be considered as a contraindication.