Comparing direct anterior approach versus posterior approach or lateral approach in total hip arthroplasty: a systematic review and meta-analysis.

BACKGROUND: There are several approaches to THA, and each has their respective advantages and disadvantages. Previous meta-analysis included non-randomised studies that introduce further heterogeneity and bias to the evidence presented. This meta-analysis aims to present level I evidence by comparing functional outcomes, peri-operative parameters and complications of direct anterior approach (DAA) versus posterior approach (PA) or lateral approach (LA) in THA. PATIENTS AND METHODS: A comprehensive multi-database search (PubMed, OVID Medline, EMBASE) was conducted from date of database inception to 1st December 2020. Data from randomised controlled trials comparing outcomes of DAA versus PA or LA in THA were extracted and analysed. RESULTS: Twenty-four studies comprising 2010 patients were included in this meta-analysis. DAA has a longer operative time (MD = 17.38 min, 95%CI: 12.28, 22.47 min, P < 0.001) but a shorter length of stay compared to PA (MD = - 0.33 days, 95%CI: - 0.55, - 0.11 days, P = 0.003). There was no difference in operative time or length of stay when comparing DAA versus LA. DAA also had significantly better HHS than PA at 6 weeks (MD = 8.00, 95%CI: 5.85, 10.15, P < 0.001) and LA at 12 weeks (MD = 2.23, 95%CI: 0.31, 4.15, P = 0.02). There was no significant difference in risk of neurapraxia for DAA versus LA or in risk of dislocations, periprosthetic fractures or VTE between DAA and PA or DAA and LA. CONCLUSION: The DAA has better early functional outcomes with shorter mean length of stay but was associated with a longer operative time than PA. There was no difference in risk of dislocations, neurapraxias, periprosthetic fractures or VTE between approaches. Based on our results, choice of THA approach should ultimately be guided by surgeon experience, surgeon preference and patient factors. LEVEL OF EVIDENCE I: Meta-analysis of randomised controlled trials.

Greater risk of all-cause revisions and complications for obese patients in 3 106 381 total knee arthroplasties: a meta-analysis and systematic review.

BACKGROUND: Obesity is a major public health issue and has considerable implications on outcomes of total knee arthroplasty (TKA). However, there has been conflicting evidence and conclusions on the effects of obesity on TKA. This meta-analysis compares the outcomes, complications, and peri-operative parameters of TKA in the obese (body mass index [BMI] ≥ 30 kg/m2 ) versus non-obese (BMI < 30 kg/m2 ) population as well as subgroup analysis of morbidly obese (BMI ≥ 40 kg/m2 ) versus non-obese population. METHODS: A meta-analysis was conducted with a multi-database search according to PRISMA guidelines on 12 September 2019. Data from all published literature meeting inclusion criteria were extracted and analysed. RESULTS: Ninety-one studies were included, consisting of 917 447 obese and 2 188 834 non-obese TKA. Obese patients had higher risk of all-cause revisions (odds ratio [OR] = 1.15, 95% CI: 1.08-1.24, p < 0.0001), all complications (OR = 1.21, 95% CI: 1.06-1.38, p = 0.004), deep infections (OR = 1.47, 95% CI: 1.27-1.69, p < 0.0001), superficial infections (OR = 1.59, 95% CI: 1.32-1.91, p < 0.0001), wound dehiscence (OR = 1.46, 95% CI: 1.24-1.72, p < 0.0001) and readmissions (OR = 1.21, 95% CI: 1.05-1.40, p = 0.009). Subgroup analysis of morbidly obese patients revealed greater risks of all-cause revisions (OR = 1.25, 95% CI: 1.10-1.43, p = 0.0009), deep infections (OR = 1.98, 95% CI: 1.05-3.75, p = 0.04), superficial infections (OR = 2.44, 95% CI: 2.08-2.88, p < 0.0001) and readmissions (OR = 1.33, 95% CI: 1.20-1.47, p < 0.0001). No analysis was performed on patient reported outcome measures due to heterogeneous reporting methods. CONCLUSION: Obese and morbidly obese patients have higher risks of revisions and infections post TKA. Surgeons should counsel patients of these risks during the informed consenting process and adopt preventative strategies into clinical practice to reduce risks where possible. In conclusion, obesity is a significant, modifiable risk factor for increased complications following TKA.

Neurons in ventral tegmental area tonically inhibit sympathetic outflow to brown adipose tissue: possible mediation of thermogenic signals from lateral habenula.

The lateral habenula (LHb), a nucleus involved in the response to salient, especially adverse, environmental events, is implicated in brown adipose tissue (BAT) thermogenesis caused by these events. LHb-elicited thermogenesis involves a neural pathway to the lower brain stem sympathetic control center in the medullary raphé. There are no direct connections from the LHb to the medullary raphé. LHb-mediated behavioral responses involve inhibitory control over the dopamine neurons in the ventral tegmental area (VTA), mediated via an excitatory drive from the LHb to GABAergic neurons in the tail of the VTA. We hypothesized that inhibition of the VTA is also involved in LHb-mediated BAT thermogenesis. To test this hypothesis, inhibition of neurons in the VTA with muscimol increased BAT sympathetic nerve discharge by 22.0 ± 9.2 dBµV ( n = 24, P < 0.0001) and BAT temperature by 1.2 ± 0.1°C ( P < 0.001). This response was abolished by inhibition of the medullary raphé neurons with muscimol. BAT thermogenesis initiated with focal injections of bicuculline in the LHb was reversed by subsequent blockade of GABAA receptors in the VTA with bicuculline. These results suggest that, at least in anesthetized rats, neurons in the VTA tonically inhibit BAT thermogenesis via a link, presently unknown, to the medullary raphé. Removal of this VTA-initiated inhibition is an important mechanism whereby LHb neurons activate BAT thermogenesis.