Comparing outcomes of medial parapatellar and subvastus approaches in total knee arthroplasty: a randomized controlled trial

The medial parapatellar (MP) approach in total knee arthroplasty is more common, but the subvastus (SV) approach is less insulting to the quadriceps. Whether the SV approach affords better outcomes was investigated using 90 participants with knee osteoarthritis, randomized to receive either SV or MP approaches and followed for 18 months. The primary outcome was the American Knee Society Score (AKSS); secondary outcomes included pain, knee range, quadriceps lag, Oxford Knee Score, 3-m timed "Up and Go" test, days to straight leg raise, surgeon perceived difficulty, operation duration, and length of stay. Analysis (n = 76) revealed no significant difference in AKSS (P = .076) or other outcomes, except the following: AKSS Functional scores at 12 and 18 months, favoring the MP (P = .032 and P = .028 respectively); surgeon's perceived difficulty, favoring the MP (P = .001); and days to straight leg raise, favoring the SV (P = .044). This study found that the SV approach offers no clinical benefit over the MP approach.     

MRI analysis of the size and shape of the oropharynx in chronic whiplash

OBJECTIVES: To quantify differences in the size/shape of the oropharynx between female subjects with whiplash and controls. DESIGN: Retrospective cohort. METHODS: A total of 113 subjects (79 whiplash, 34 controls) were included. T1-weighted MRI was used to measure 1) cross-sectional area (CSA [mm(2)]) and 2) shape ratios for the oropharynx. Reliability data were established. RESULTS: Whiplash subjects had significantly smaller oropharynx CSAs (P < 0.001) and shape ratios (P < 0.001) compared with healthy controls. Self-reported levels of pain and disability and duration of symptoms were not associated with size and shape of the oropharynx in whiplash subjects (P = 0.75 and P = 0.99, respectively). Age and BMI did influence the size (P = 0.01) and shape of the oropharynx (P < 0.001) in the whiplash subjects, but only 20 to 30 percent of the variance could be explained by these factors. CONCLUSION: Significant difference in the size and shape of the oropharynx was noted in subjects with chronic whiplash compared with controls. Future studies are required to investigate the relationships between oropharynx morphometry and symptoms in patients with chronic whiplash.     

Effect of cyclic pneumatic soft tissue compression on simulated distal radius fractures

We investigated the effect of pneumatic pressure applied to the proximal musculature of the sheep foreleg on load at the site of a transverse osteotomy of the distal radius. The distal radii of 10 fresh sheep foreleg specimens were osteotomized and a pressure sensor was inserted between the two bone fragments. An inflatable cuff, connected to a second pressure sensor, was positioned around the proximal forelimb musculature and the leg then was immobilized in a plaster cast. The inflatable cuff was inflated and deflated repeatedly to various pressures. Measurements of the cuff pressure and corresponding change in pressure at the osteotomy site were recorded. The results indicated that application of pneumatic pressure to the proximal foreleg musculature produced a corresponding increase in load at the osteotomy site. For the cuff pressures tested (109.8-238.4 mm Hg), there was a linear correlation with the load at the osteotomy site with a gradient of 12 mm Hg/N. It is conceivable, based on the results of this study, that a technique could be developed to provide dynamic loading to accelerate fracture healing in the upper limb of humans.     

Nicotinic receptor-mediated activation by the tobacco-specific nitrosamine NNK of a Raf-1/MAP kinase pathway, resulting in phosphorylation of c-myc in human small cell lung carcinoma cells and pulmonary neuroendocrine cells

OBJECTIVE: Small cell lung carcinoma (SCLC) expresses phenotypic features of pulmonary neuroendocrine cells and demonstrates a strong etiologic association with smoking. SCLC cell lines express a Raf-1-dependent mitogenic signal transduction pathway, which is thought to transduce the mitogenic signals initiated by neuropeptide autocrine growth factors. Recent studies have identified the tobacco-specific carcinogenic nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) as a site-selective high-affinity agonist for the alpha7 nicotinic acetylcholine receptor (alpha7 nAChR), which regulates the growth of a significant subset of SCLC in vitro by stimulating the release of the autocrine growth factor serotonin. The purpose of this study was to identify signaling events initiated by binding of NNK to the alpha7 nAChR. DESIGN: We have used a human SCLC cell line and fetal hamster pulmonary neuroendocrine cells with in vitro kinase activation assays and western blots to assess the levels of expression and activation of Raf-1, MAPK and c-myc to address this issue. RESULTS: Our data show that NNK activates the Raf-1, MAP kinase pathway, resulting in phosphorylation of c-myc. The activation of this signal transduction pathway by NNK was inhibited by the site-selective antagonist for the alpha7 nAChR alpha-bungarotoxin (alpha-BTX) or by the serotonin reuptake inhibitor imipramine, suggesting that the responses to NNK were mediated by nicotinic receptor-initiated release of serotonin. Accordingly, NNK-induced 5-HT release was blocked by alpha-BTX while NNK-induced DNA synthesis was inhibited by alpha-BTX, imipramine, the PKC inhibitor sphingosine or the MEK inhibitor PD98059. SCLC cells demonstrated high basal levels of 5-HT release, DNA synthesis, and over-expressed Raf-1 and MAPK protein suggesting the constitutive activation of an upstream regulator such as the alpha7 nAChR. CONCLUSION: Our findings link, for the first time, the stimulation of a nicotinic acetylcholine receptor by a cancer-causing agent with the activation of a Raf-1/MAPK/c-myc signaling pathway. Furthermore, our data suggest that serotonin uptake inhibitors may protect against the development or be useful in the clinical management of SCLC.     

Energy expended playing video console games: an opportunity to increase children's physical activity?

This study sought to quantify the energy expenditure and physical activity associated with playing the "new generation" active and nonactive console-based video games in 21 children ages 10-14 years. Energy expenditure (kcal) derived from oxygen consumption (VO2) was continuously assessed while children played nonactive and active console video games. Physical activity was assessed continuously using the Actigraph accelerometer. Significant (p < .001) increases from baseline were found for energy expenditure (129-400%), heart rate (43-84%), and activity counts (122-1288 versus 0-23) when playing the active console video games. Playing active console video games over short periods of time is similar in intensity to light to moderate traditional physical activities such as walking, skipping, and jogging.     

Does the presence of sensory hypersensitivity influence outcomes of physical rehabilitation for chronic whiplash?--A preliminary RCT

Patients with chronic whiplash associated disorders present with varied sensory, motor and psychological features. In this first instance it was questioned whether a multimodal program of physical therapies was an appropriate management to be broadly prescribed for these patients when it was known that some would have sensory features suggestive of a notable pain syndrome. A randomised controlled trial was conducted with 71 participants with persistent neck pain following a motor vehicle crash to explore this question. Participants were randomly allocated to receive either a multimodal physiotherapy program (MPT) or a self-management program (SMP) (advice and exercise). In the randomisation process, participants were stratified according to the presence or not of widespread mechanical or cold hyperalgesia. The intervention period was 10 weeks and outcomes were assessed immediately following treatment. Even with the presence of sensory hypersensitivity in 72.5% of subjects, both groups reported some relief of neck pain and disability (Neck Disability Index) and it was superior in the group receiving multimodal physiotherapy (p=0.04). Post-hoc observations however suggested that relief was marginal in the subgroup with both widespread mechanical and cold hyperalgesia. Further research is required to test the validity of this sub-group observation and to test the effect of the intervention in the long term.     

The effect of a scapular postural correction strategy on trapezius activity in patients with neck pain

Extensive computer use amongst office workers has lead to an increase in work-related neck pain. Aberrant activity within the three portions of the trapezius muscle and associated changes in scapular posture have been identified as potential contributing factors. This study compared the activity (surface electromyography) of the three portions of the trapezius in healthy controls (n = 20) to a neck pain group with poor scapular posture (n = 18) during the performance of a functional typing task. A scapular postural correction strategy was used to correct scapular orientation in the neck pain group and electromyographic recordings were repeated. During the typing task, the neck pain group generated greater activity in the middle trapezius (MT) (p = 0.02) and less activity in the lower trapezius (LT) (p = 0.03) than the control group. Following correction of the scapula, activity recorded by the neck pain group was similar to the control group for the middle and lower portions (p = 0.09; p = 0.91). These findings indicate that a scapular postural correction exercise may be effective in altering the distribution of activity in the trapezius to better reflect that displayed by healthy individuals.