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

Does venous thromboembolism prophylaxis affect the risk of venous thromboembolism and adverse events following primary hip and knee replacement?:A retrospective cohort study

BACKGROUND: The optimum chemical venous thromboembolism (VTE) prophylactic agents following total hip and knee replacement (THR and TKR) remain unknown. NICE recommends multiple agents, including direct oral anticoagulants (DOACs), low-molecular weight heparin (LMWH), and aspirin. We assessed whether VTE prophylaxis affected the risk of VTE and adverse events following primary THR and TKR. MATERIALS AND METHODS: We reviewed 982 elective primary THRs (59%) and TKRs (41%) at a large tertiary centre during 2018. The primary outcome was any VTE (DVT and/or PE) within 90-days. Secondary outcomes were adverse events within 90-days (major bleeding and wound complications). The association between VTE prophylaxis and outcomes was assessed. RESULTS: The overall prevalence of VTE and adverse events were 2.7% (n = 27) and 15.2% (n = 136) respectively. The most common agents used were DOAC ± LMWH (50.7%, n = 498), followed by aspirin ± LMWH (35.5%, n = 349) and LMWH alone (4.7%, n = 46). The risk of VTE (aspirin ± LMWH = 3.7%, DOAC = 2.0%, LMWH = 2.2%) was not significantly different between agents (p = 0.294). The risk of any adverse event was significantly higher (p < 0.001) with aspirin ± LMWH (16.1%; n = 56) and LMWH (28.3%; n = 13) compared with DOACs ± LMWH (7.0%; n = 35) in TKRs only, there was no differences between agents for adverse events in THRs (p = 0.644). CONCLUSIONS: Choice of thromboprophylaxis did not influence the risk of VTE following primary THR and TKR. DOACs (+/− LMWH) were associated with the lowest risk of adverse events. Large multicentre trials are still needed to assess the efficacy and safety of these agents following THR and TKR

Estimation of blood volume and blood loss in primary total hip and knee replacement:An analysis of formulae for perioperative calculations and their ability to predict length of stay and blood transfusion requirements

INTRODUCTION: Blood loss continues to be a common surgical risk in total hip (THR) and knee replacements (TKR). Accurate prediction of blood loss permits appropriate counselling of risks to patients, target optimisation and forecasting future transfusion requirements. We compared blood volume formulae of Moore and Nadler, and blood loss formulae of Liu, Mercuriali, Bourke, Ward, Gross, Lisander and Meunier, to assess associations between calculated values with length of stay and transfusion requirements and determine which are useful in contemporary practice. METHODS: We retrospectively studied patients undergoing primary THR and TKR. We collected data on patient demographics, surgical interventions, pre- and postoperative haemoglobin and haematocrit values, length of stay and blood transfusion requirements. Spearman correlation tests and least squares multiple linear regression were performed. RESULTS: 149 THRs and 90 TKRs in 239 patients were analysed over four months. There was a very strong correlation between blood volume formulae. There were multiple very strong and strong associations between blood loss formulae. Bourke correlated significantly to length of stay, and Liu, Mercuriali, Lisander and Meunier correlated for incidence of transfusion. CONCLUSION: Accurate estimation of perioperative blood loss is increasingly important as demand for joint replacement surgery increases in an ageing population. If the primary interest is the association of blood loss and length of stay, Bourke's formula should be preferred. If the primary interest is calculating risk of transfusion, the formulae of Liu or Meunier should be preferred. The formulae of Mercuriali and Lisander are becoming redundant in contemporary practice

Surgical Versus Non-surgical Treatment of Unstable Lateral Compression Type I (LC1) Injuries of the Pelvis With Complete Sacral Fractures in Non-fragility Fracture Patients:A Systematic Review

Lateral compression type 1 (LC1) injuries comprise two-thirds of pelvic fractures. Approximately one-third of LC1 fractures are unstable and may benefit from surgical fixation to improve stability but it is not clear if this leads to better clinical or cost-effectiveness outcomes. This study explores differences in patient-reported outcomes, complications, time-to-mobilisation, cost-effectiveness, and length of hospital stay between surgically and non-surgically treated unstable LC1 non-fragility fractures. We performed a systematic review to determine whether surgical or non-surgical treatment yielded better clinical and cost-effectiveness outcomes for the treatment of unstable LC1 pelvic injuries with complete sacral fractures, excluding fragility fractures. We searched Medline, Embase and Cochrane databases from inception to June 2022, as well as clinical trial registries. A formal meta-analysis was not possible due to available study designs and heterogeneity. Therefore, a narrative review of the findings has been provided. Five observational studies met the inclusion criteria. A total of 183 patients were treated surgically, and 314 patients were treated non-surgically. Patients treated surgically had lower pain levels (Visual Analogue Scale) and fewer days to mobilisation. Quality of life (EuroQol-5 domains and 36-Item Short Form questionnaires) was better in the surgical group, but not statistically significant. No statistical differences in the length of hospital stay or complication rates were found. This review highlights the low quantity and quality of existing data on patients with unstable LC1 pelvic fractures and the need for a definitive randomised controlled trial to determine whether surgical or non-surgical care should be the preferred treatment concerning clinical and cost-effective care