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Background: We sought to utilize a noninvasive technology to assess the effects of activity on Achilles tendon stiffness and define baseline Achilles tendon stiffness in female college athletes compared with nonathletes using tendon shear wave velocity as a marker for tendon stiffness. Hypothesis: Training status and exercise may affect Achilles tendon stiffness. Study Design: Level of Evidence: Level 4. Methods: A total of 32 college-age female athletes were prospectively enrolled (n = 17 varsity athletes and n = 15 nonathletes). Demographic characteristics, activity level, and previous injuries were recorded. Sonographic shear wave elastography (SWE) was used to assess Achilles tendon shear wave velocity bilaterally for all subjects, both at baseline and after 2 minutes of exercise. Student t tests were used to compare the mean elastography measurements between participants stratified by athlete status and pre/postexercise stimulus. Analysis of variance (ANOVA) was used to compare the mean proximal, middle, and distal Achilles tendon elastography measurements. Results: As seen by a greater mean shear wave velocity (8.60 ± 1.58 m/s vs 8.25 ± 1.89 m/s; P = 0.02), athletes had stiffer tendons than nonathletes. Exercise stimulus decreased average tendon shear wave velocity (8.57 ± 1.74 m/s vs 8.28 ± 1.72 m/s; P = 0.05). Tendon shear wave velocity was greatest proximally and least distally with significant differences between each region (P < 0.001). In addition, there was a significant 2-way interaction between weekly training status and foot dominance (P = 0.01). Post hoc analysis showed that this result was due to differences in tendon shear wave velocity between the dominant and nondominant lower extremity in nonathletes (7.73 ± 2.00 m/s vs 8.76 ± 1.62 m/s; P < 0.001). Conclusion: Female varsity collegiate athletes have higher baseline Achilles tendon stiffness as measured by SWE compared with nonathletes. Mean tendon stiffness varies based on Achilles measurement location. SWE is a quick, cost-effective, and noninvasive imaging modality that can be used to evaluate tendon stiffness and elasticity. Clinical Relevance: SWE is an efficient and noninvasive imaging modality that can evaluate dynamic tendon stiffness and elasticity. SWE may be helpful to assess injuries in female college athletes and may play a role in risk stratification or clinical follow-up. In theory, SWE could be used to identify athletes with increased elasticity as a marker for potential risk for rupture in this population. [ABSTRACT FROM AUTHOR]

Background: Cigarette smoking adversely affects fracture repair, causing delayed healing or nonunion rates twice those seen in nonsmokers. Purpose: We sought to investigate if cigarette smoke differentially affects intramembranous and endochondral healing of fractures. We hypothesize that healing via endochondral ossification will be preferentially impaired compared to intramembranous ossification. Methods: We utilized a bilateral femur fracture model in Sprague Dawley rats to examine effects of cigarette smoke exposure on healing of femur fractures, treated with either locked intramedullary nail or compression plating to induce endochondral and membranous ossification, respectively. Animals were exposed to tobacco smoke 30 days before and after surgery; evaluations included radiographs, histomorphometry, and micro-CT at 10 days, 1, 3, and 6 months postoperation, and biomechanical testing at 3 and 6 months. Results: Sixty-eight animals were randomized to control or exposure (two died perioperatively); 89% of femora achieved union when harvested at 3 or 6 months. Smoke exposure delayed cartilaginous callus formation and bone maturation in nailed fractures compared to plated fractures and controls in the same animals. Plated fractures in exposed animals exhibited little cartilage callus and healed like control animals. At 3 months, plated fractures were stiffer and stronger than nailed fractures in both groups. These differences vanished by 6 months. Conclusions: Plated fractures healed more rapidly and completely than nailed fractures under both control and smoke-exposed conditions. Clinical Relevance: Using compression plating instead of IM nailing for closed long bone fractures may lead to better outcomes in patients who smoke compared to current results with nailing. [ABSTRACT FROM AUTHOR]

Chemical loading of aequorin in the ferret cardiac muscle with computer controlled low-photon counting and digital processing helps in the analysis of intracellular Ca2+ concentration. While an increase is noted in the systolic (Ca2+)i, the diastolic (Ca2+)i remains unchanged. Exposure to low Na+ containing superfusate demonstrates a beat-to-beat correspondence in the increase of diastolic (Ca2+)i. Both tension transients and beat-to-beat measurements of (Ca2+)i can be obtained in multicellular cardiac preparations with a good resolution.

Background: Infection following wrist arthroplasty (WA) or wrist fusion (WF) is an uncommon but difficult complication often resulting in explantation and prolonged courses of antibiotics. The purposes of this study are to: (1) characterize the demographic trends of individuals undergoing WA and WF; (2) determine the incidence of postoperative infection; and (3) identify risk factors for postoperative infection. Methods: The PearlDiver database was used to query 100% Medicare Standard Analytic files from 2005 to 2014. Patients undergoing WA or radiocarpal WF were identified using Current Procedural Terminology (CPT) codes. Diagnosis for infection within 1 year of operative intervention was assessed by International Classification of Diseases, Ninth Revision codes or CPT codes related to infection. Multivariable logistic regression analyses were performed to evaluate the risk factors for postoperative infection. Results: Of the 6641 patients included, 1137 (17.1%) underwent arthroplasty and 5504 (82.9%) underwent arthrodesis. Within 1 year of the index procedure, 3.5% had a diagnosis of, or procedure for, postoperative infection (WA: n = 40 of 1137; WF: n = 192 of 5504). Risk factors for infection following WA include age >85, tobacco use, depression, diabetes mellitus, and chronic kidney disease. Risk factors following radiocarpal WF include male sex, age >85, body mass index <19 kg/m2, depression, diabetes mellitus, and chronic kidney disease. Posttraumatic origin of wrist arthritis was a risk factor for infection following both WA and WF. Conclusions: Infection following WA and WF is relatively uncommon in a nationally representative Medicare database cohort. Risk factors common to both WA and WF include age >85, depression, diabetes mellitus, chronic kidney disease, and posttraumatic arthritis. [ABSTRACT FROM AUTHOR]