Intermittent tourniquet compared to throughout tourniquet use during Total Knee Arthroplasty in patients with Body Mass Index of 30 or more: A retrospective cohort study.

Background: Tourniquet use during total knee arthroplasty (TKA) reduces bleeding which optimises bone-cement interface for prosthesis stability and improves surgical field visualisation. However, prolonged usage can lead to complications and poorer outcomes. Some surgeons advocate for intermittent tourniquet application. Limited literature exists for patients with high body mass index (BMI). This study aims to compare the outcomes of intermittent tourniquet (IT) to throughout tourniquet (TT) use among obese patients undergoing primary TKA for knee osteoarthritis. Methods: This was a retrospective cohort study. In the TT group, tourniquet was inflated from the beginning and released once the bone cement has hardened. In the IT group, tourniquet was inflated at the beginning, released after initial incision and haemostasis, then inflated again during cementation. Tourniquet was released once the bone cement had set. Categorical outcome measures were analysed using Chi-squared or Fisher's exact test. T-test or Kruskal-Wallis test were used for continuous data. Results: When comparing IT to TT among patients with BMI≥30 (IT n = 48, TT n = 47), the mean duration of surgery was shorter in the TT group (p < 0.05). The difference in haemoglobin drop between the two groups was not statistically significant from post-operative day three onwards. There was no difference in transfusion rate (p > 0.05). ROM was greater in the IT group up to three weeks post-operatively (p < 0.05). When comparing patients with BMI <30 (n = 71) and BMI≥30 (n = 48) with IT use, there was no statistically significant difference in ROM and LOS. Conclusion: Patients with BMI≥30 in the IT group had greater ROM in the initial post-operative period. Although operative time and blood loss were greater among the IT group, there was no difference in transfusion rate. Outcomes of TKA performed with IT were similar for patients with BMI≥30 and BMI <30. The authors recommend intermittent tourniquet use during TKA for patients with BMI≥30. Level of evidence: 3.

The Orthopedic Injury Burden of Personal Mobility Devices in Singapore - Our Experience in the East Coast.

PURPOSE: Personal mobility devices (PMDs) have become increasingly popular as a modality of transport worldwide. Starting out as novelty toys, PMDs are gradually being adopted as the mainstream mode of travel. There is an increasing number of accidents involving both PMD riders and other road users since its introduction, leading to a concomitant increase in demand for healthcare resources to manage the injuries. The main objective of this study was to evaluate the inpatient cost and the orthopedic injury pattern due to PMD accidents. METHODS: All patients admitted to the Department of Orthopedic Surgery between December 2016 to February 2018 with injuries due to PMD accidents were recruited. Data collection was performed retrospectively on the demographic profiles, injury patterns, admission related outcomes and expenditures of these patients. RESULTS: 43 patients were included in this study. The mean duration of admission was 7.81 days and the median cost of admission was S$7835.01 (approximately US$5620). These were comparable to accidents arising from other modes of transport, such as motorcycles and bicycles. In addition, more than 80% of patients were not wearing protective gear at time of accident. These patients had a slightly higher median cost payable per patient as compared to those who donned protective gear, with a difference of S$1669.78 (approximately US$1221). CONCLUSION: There is a significant health and financial cost to the individual and society from PMD injuries and admission. This can be reduced with strict regulations on PMD use, advocating protective gear use, and promoting awareness on safety measures and the consequences of PMD accidents. The most common injury mechanism and orthopedic injury type for PMD accidents are different from motorcycle accidents.

A reproducible reference point for the common peroneal nerve during surgery at the posterolateral corner of the knee: a cadaveric study.

BACKGROUND: This is an experimental study conducted to assess whether the fibular head is a reliable reference point to identify the position of the common peroneal nerve at the posterolateral corner of the knee. MATERIALS AND METHODS: Twelve cadaveric knees were dissected through the lateral approach. The common peroneal nerve was identified and traced. The location where the common peroneal nerve crossed the posterior border of the biceps femoris and the posterior border of the fibular neck were designated as points B and N, respectively. The tip of the fibular head was designated F. Distances FB and FN were measured and the triangular area FBN was calculated at various degrees of knee flexion. RESULTS: During knee motion, distance FN showed minimal change and was not affected by variation in degrees of knee flexion (p = 0.131). Distance FB and distance BN were affected by variation in degrees of knee flexion (p < 0.001). Triangular area FBN increased in size up to 60° of knee flexion measuring 621.22 mm2 and subsequently decreased with further knee flexion. CONCLUSION: The common peroneal nerve can consistently be found at approximately 20.7 ± 1 mm on the fibular neck with respect to the tip of the fibular head. The tip of the fibular head is a consistent landmark that can be used to predict the position of the exit point of the common peroneal nerve at the posterolateral corner of the knee.

QSAR classification of metabolic activation of chemicals into covalently reactive species.

Metabolic activation of chemicals into covalently reactive species might lead to toxicological consequences such as tissue necrosis, carcinogenicity, teratogenicity, or immune-mediated toxicities. Early prediction of this undesirable outcome can help in selecting candidates with increased chance of success, thus, reducing attrition at all stages of drug development. The ensemble modelling of mixed features was used for the development of a model to classify the metabolic activation of chemicals into covalently reactive species. The effects of the quality of base classifiers and performance measure for sorting were examined. An ensemble model of 13 naive Bayes classifiers was built from a diverse set of 1,479 compounds. The ensemble model was validated internally with five-fold cross validation and it has achieved sensitivity of 67.4% and specificity of 93.4% when tested on the training set. The final ensemble model was made available for public use.