Near infrared spectroscopy for monitoring flap viability following breast reconstruction

Free flap monitoring is essential to the early detection of compromise thereby increasing the chance of successful salvage surgery. Many alternatives to classical clinical monitoring have been proposed. This study seeks to investigate a relatively new monitoring technology: near infrared spectroscopy (NIRS). Patients were recruited prospectively to the study from a single center. During the research period, 10 patients underwent reconstruction with a free deep inferior epigastric perforator flap (DIEP). Measurements of flap perfusion were taken using NIRS in the preoperative and intraoperative phases and postoperatively for 72 hours. NIRS showed characteristic changes in all cases which returned to theater for pedicle compromise. In these cases, NIRS identified pedicle compromise prior to clinical identification. There were no false-positives. NIRS accurately identified all compromised flaps in our study. In most cases, there was an evidence of changes in oxygen saturation on NIRS prior to clinical observation. Further research, ideally double blind randomized control trials with large sample groups would be required to definitively establish NIRS as an ideal flap monitoring modality.     

Open‐MRI measures of cam intrusion for hips in an anterior impingement position relate to acetabular contact force

Open MRI in functional positions has potential to directly and non‐invasively assess cam femoroacetabular impingement (FAI). Our objective was to investigate whether open MRI can depict intrusion of the cam deformity into the intra‐articular joint space, and whether intrusion is associated with elevated acetabular contact force. Cadaver hips (9 cam; 3 controls) were positioned in an anterior impingement posture and imaged using open MRI with multi‐planar reformatting. The β‐angle (describing clearance between the femoral neck and acetabulum) was measured around the entire circumference of the femoral neck. We defined a binary “MRI cam‐intrusion sign” (positive if β < 0°). We then instrumented each hip with a piezoresistive sensor and conducted six repeated positioning trials, measuring acetabular contact force (F). We defined a binary “contact‐force sign” (positive if F > 20N). Cam hips were more likely than controls to have both a positive MRI cam‐intrusion sign (p = 0.0182, Fisher's exact test) and positive contact‐force sign (p = 0.0083), which represents direct experimental evidence for cam intrusion. There was also a relationship between the MRI cam‐intrusion sign and contact‐force sign (p = 0.033), representing a link between imaging and mechanics. Our findings indicate that open MRI has significant potential for in vivo investigation of the cam FAI mechanism. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:205–216, 2016.     

Magnetic resonance imaging of bone destruction in rheumatoid arthritis: comparison with radiography

Bony changes in forty-four knees of patients with clinically established rheumatoid arthritis (RA) were examined using magnetic resonance imaging (MRI) and plain film radiography. In all cases MRI was clearly superior to radiographs, demonstrating 25 marginal erosions and 42 subchondral cysts, while the number seen on radiographs was 3 and 8, respectively. These results emphasize the problems in visualizing bone erosions in large joints using plain films. MRI is the method of choice for detecting early changes in RA, not only because of its high sensitivity, but also because of the ability of contrast-enhanced MRI to provide physiological characterization of these lesions.     

Interventional radiology: a web review

There is a wealth of information available on the World Wide Web relating to interventional radiology. The authors reviewed resources that may be pertinent to trainees at all stages, interventional radiology specialists, physicians in other specialties, and patients.     

Trained men display increased basal heat shock protein content of skeletal muscle

PURPOSE: 1) To compare the baseline levels of heat shock and antioxidant protein content in the skeletal muscle of trained and untrained humans and 2) to characterize the exercise-induced stress response of aerobically trained human skeletal muscle to an acute exercise challenge. METHODS: Resting muscle biopsies were obtained from the vastus lateralis muscle of six untrained and six aerobically trained young males. To characterize the stress response of a trained population, the trained subjects also performed a 45-min nondamaging running exercise protocol at an intensity corresponding to 75% of V O2max. Muscle biopsies were obtained from the vastus lateralis muscle at 48 h and 7 d after exercise. RESULTS: Trained subjects displayed significantly higher (P<0.05) resting levels of heat shock protein 60 (HSP60, 25%), alphaB-crystallin (43%), and manganese superoxide (MnSOD, 45%) protein content compared with untrained subjects. Trained subjects also exhibited no significant change (P > 0.05) in resting levels of HSP70 (16%), HSC70 (13%), and total superoxide dismutase (SOD) activity (46%) compared with untrained subjects. Resting HSP27 levels were unaffected by exercise training (P > 0.05). In the trained subjects, exercise failed to induce significant increases (P>0.05)in muscle content of HSP70, HSC70, HSP60, HSP27, alphaB-crystallin, and MnSOD protein content or in the activity of SOD at any time point after exercise. CONCLUSION: This study demonstrates for the first time that trained men display a selective up-regulation of basal heat shock and antioxidant protein content and do not exhibit a stress response to customary running exercise. It is suggested that an increase in these protective systems functions to maintain homeostasis during the stress of exercise by protecting against disruptions to the cytoskeleton/contractile machinery, by maintaining redox balance, and by facilitating mitochondrial biogenesis.     

Estimating the age of immature <Emphasis Type="Italic">Chrysomya albiceps</Emphasis> (Diptera: Calliphoridae), correcting for temperature and geographical latitude

Developmental curves for Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae) were established at 13 different constant temperatures using developmental landmarks and length as measures of age. The thermal summation constants (K) and developmental zeros (D (0)) were calculated for five developmental landmarks using the method described by Ikemoto and Takai (Environ Entomol 29:671-682, 2000). Comparison with the K and D (0) values of our findings to those of three previously published studies of C. albiceps suggests that K is directly proportional to geographic latitude, and D (0) is inversely proportional to both K and geographic latitude. Body size and developmental landmarks have a complex relationship because of trade-offs between mortality risk and female fecundity (as measured by body size) at non-optimal temperatures. This relationship can be summarized using superimposed isomorphen and isomegalen diagrams, which can then be used to make forensic estimates of postmortem intervals from larval body lengths. Finally, we recommend that future studies providing data for precise forensic estimates of postmortem intervals should use a relative temporal precision of about 10% of the total duration being measured. For many blowflies, this translates into a sampling interval of approximately every 2 h before hatching, 3 h before first ecdysis and 6 h before second ecdysis.     

Patient-controlled epidural analgesia (PCEA) for postoperative pain control after lumbar spine surgery

Spine surgery remains one of the most common procedures for patients with a wide variety of spine disorders. Postoperative pain after major spine surgery is moderate to severe. We retrospectively reviewed 245 medical records of adult patients undergoing major spine surgery who received either patient-controlled epidural analgesia based on local anesthetics and opioids or patient-controlled intravenous analgesia as postoperative pain management. Several outcomes were analyzed including pain intensity, opioid consumption, time to endotracheal extubation, the incidence of deep venous thrombosis, and length of stay in the hospital. We found that the use of patient-controlled epidural analgesia provided better postoperative analgesia [median (quartiles) verbal analog scale score of 4 (3, 5) vs. 5 (3, 6)] and decreased the amount of opioid consumption postoperatively [median of 0 mg (0, 3) vs. 35 mg (0, 150)] compared with patient-controlled intravenous analgesia. Also, a substantially higher number of patients in the patient-controlled intravenous group required opioids as rescue analgesia. Incidences of deep venous thrombosis, operating room extubation, and length of stay in the hospital were not associated with the analgesic technique. The results of this study suggest that the use of neuroaxial analgesia for the management of postoperative pain associated with major spine surgery may have some beneficial properties over intravenous analgesia. The use of a reduced amount of opioids by patients with epidural analgesia may be relevant because of potential fewer side effects mainly in elderly patients. Several limitations related to the retrospective nature of the study are described. Prospective randomized-controlled trials are needed to understand and elucidate the optimum regimen of postoperative pain management after major spine surgery.     

Upper limb function improvement following total elbow arthroplasty in patients with rheumatoid arthritis

Thirty-one primary total elbow replacements were implanted in 25 patients with rheumatoid arthritis between 2000 and 2004 by a surgeon. Twenty-six implants were GSB III. Seven were Coonrad–Morrey prostheses. The mean age of the patients was 70 years (40–88); 18 women, 6 men. DASH scores were recorded pre-operatively and at their latest review. Patients were also assessed according to the Mayo elbow performance score post-operatively. Mean follow-up was 29 months (8–55). The mean improvement in DASH (disabilities of the arm, shoulder and hand) was 25 (+6 to −45). The mean Mayo score (Corectly is the Mayo Elbow Score, there is also a Mayo liver score and other scores prposed in this center) was 85 (15–100). One implant was removed following deep infection (3%). One implant has been revised secondary to ulnar component fracture. Our overall major complication rate was 7%.