Obesity and Anesthesia: Challenges in the Perioperative Period.

The obesity epidemic has significant implications for all aspects of healthcare. The physiological changes of obesity affect every area of perioperative medicine. In this article, we discuss several anesthetic concerns regarding obesity. We will specifically discuss preoperative evaluation, perioperative challenges, and postoperative pain control and monitoring.

Decreased Range of Motion After Total Knee Arthroplasty Is Predicted by the Tampa Scale of Kinesiophobia.

BACKGROUND: Range of motion (ROM) is important for functional outcome after total knee arthroplasty (TKA); however, some patients hesitate to maximize their ROM postoperatively. The Tampa Scale of Kinesiophobia (TSK) measures patients' fear of movement. The primary purpose of this investigation was to determine whether TSK scores correlated with decreased ROM after primary TKA. A secondary purpose was to determine whether biofeedback could increase ROM after TKA. METHODS: Patients were recruited from the senior author's practice between June 2011 and March 2013. A clinical photograph was taken of each patient's knee in maximum passive flexion in the operating room immediately following closure. Patients were randomized to the control or photograph group before incision. A linear mixed model was implemented to determine whether the TSK score and viewing the photo correlated to ROM. RESULTS: Seventy-nine patients were analyzed for correlation between the TSK score and the knee ROM. Sixty patients were analyzed for correlation between viewing the clinical photograph and the knee ROM. The linear mixed model demonstrated a significant negative correlation between the TSK score and both active (ß = -0.47, P < .01) and passive (ß = -0.66, P < .001) knee flexions. There was a trend toward decreased knee flexion among patients shown their clinical photograph. CONCLUSION: The TSK was developed as a tool to identify patients at risk for maladaptive responses to painful stimuli. Our data suggest that the TSK may help arthroplasty surgeons identify patients at risk for decreased ROM after TKA. Showing patients a clinical photograph failed to increase ROM after TKA.

Improved MR-based characterization of engineered cartilage using multiexponential T2 relaxation and multivariate analysis.

Noninvasive monitoring of tissue quality would be of substantial use in the development of cartilage tissue engineering strategies. Conventional MR parameters provide noninvasive measures of biophysical tissue properties and are sensitive to changes in matrix development, but do not clearly distinguish between groups with different levels of matrix development. Furthermore, MR outcomes are nonspecific, with particular changes in matrix components resulting in changes in multiple MR parameters. To address these limitations, we present two new approaches for the evaluation of tissue engineered constructs using MR, and apply them to immature and mature engineered cartilage after 1 and 5 weeks of development, respectively. First, we applied multiexponential T(2) analysis for the quantification of matrix macromolecule-associated water compartments. Second, we applied multivariate support vector machine analysis using multiple MR parameters to improve detection of degree of matrix development. Monoexponential T(2) values decreased with maturation, but without further specificity. Much more specific information was provided by multiexponential analysis. The T(2) distribution in both immature and mature constructs was qualitatively comparable to that of native cartilage. The analysis showed that proteoglycan-bound water increased significantly during maturation, from a fraction of 0.05 ± 0.01 to 0.07 ± 0.01. Classification of samples based on individual MR parameters, T(1), T(2), k(m) or apparent diffusion coefficient, showed that the best classifiers were T(1) and k(m), with classification accuracies of 85% and 84%, respectively. Support vector machine analysis improved the accuracy to 98% using the combination (k(m), apparent diffusion coefficient). These approaches were validated using biochemical and Fourier transform infrared imaging spectroscopic analyses, which showed increased proteoglycan and collagen with maturation. In summary, multiexponential T(2) and multivariate support vector machine analyses provide improved sensitivity to changes in matrix development and specificity to matrix composition in tissue engineered cartilage. These approaches show substantial potential for the evaluation of engineered cartilage tissue and for extension to other tissue engineering constructs.