Computed tomographic analysis of the quality of trunk muscles in asymptomatic and symptomatic lumbar discectomy patients

Background: No consensus exists on how rehabilitation programs for lumbar discectomy patients with persistent complaints after surgery should be composed. A better understanding of normal and abnormal postoperative trunk muscle condition might help direct the treatment goals. Methods: A three-dimensional CT scan of the lumbar spine was obtained in 18 symptomatic and 18 asymptomatic patients who had undergone a lumbar discectomy 42 months to 83 months (median 63 months) previously. The psoas muscle (PS), the paraspinal muscle mass (PA) and the multifidus muscle (MF) were outlined at the L3, L4 and L5 level. Of these muscles, fat free Cross Sectional Area (CSA) and fat CSA were determined. CSA of the lumbar erector spinae (LES = longissimus thoracis + iliocostalis lumborum) was calculated by subtracting MF CSA from PA CSA. Mean muscle CSA of the left and right sides was calculated at each level. To normalize the data for interpersonal comparison, the mean CSA was divided by the CSA of the L3 vertebral body (mCSA = normalized fat-free muscle CSA; fCSA = normalized fat CSA). Differences in CSA between the pain group and the pain free group were examined using a General Linear Model (GLM). Three levels were examined to investigate the possible role of the level of operation. Results: In lumbar discectomy patients with pain, the mCSA of the MF was significantly smaller than in pain-free subjects (p = 0.009) independently of the level. The mCSA of the LES was significantly smaller in pain patients, but only on the L3 slice (p = 0.018). No significant difference in mCSA of the PS was found between pain patients and pain-free patients (p = 0.462). The fCSA of the MF (p = 0.186) and of the LES (p = 0.256) were not significantly different between both populations. However, the fCSA of the PS was significantly larger in pain patients than in pain-free patients. (p = 0.012). The level of operation was never a significant factor. Conclusions: CT comparison of MF, LES and PS muscle condition between lumbar discectomy patients without pain and patients with protracted postoperative pain showed a smaller fat-free muscle CSA of the MF at all levels examined, a smaller fat-free muscle CSA of the LES at the L3 level, and more fat in the PS in patients with pain. The level of operation was not found to be of importance. The present results suggest a general lumbar muscle dysfunction in the pain group, in particular of the deep stabilizing muscle system

Delayed vastus medialis obliquus to vastus lateralis onset timing contributes to the development of patellofemoral pain in previously healthy men : a prospective study

Background: Delayed onset of vastus medialis obliquus activity has been described in patellofemoral pain patients. No prospective study investigating the development of patellofemoral pain has tested the onset timing of electromyographic activity of the vastus medialis obliquus and vastus lateralis muscles during a functional task. Hypothesis: Before the development of patellofemoral pain, subjects demonstrate an altered firing order of the vastus medialis obliquus and vastus lateralis muscles compared with healthy subjects during a functional task. Study Design: Cohort study; Level of evidence, 2. Methods: The onset of vastus medialis obliquus and vastus lateralis activity was measured with surface electromyography during a functional task (rocking back on the heels) in 79 healthy subjects subsequently submitted to a 6-week strenuous basic military training. Afterward, these subjects were reassessed. Results: Thirty-two percent of the recruits developed patellofemoral pain during training. Patellofemoral pain subjects demonstrated a significant delay of onset of vastus medialis obliquus electromyographic activity compared with the healthy controls (P = .023), even before basic military training. In healthy subjects, no significant differences in electromyographic activity onset of the vastus medialis obliquus compared with the vastus lateralis could be identified before and after basic military training. A significant (P < .001) delay could be demonstrated in the patellofemoral pain group after basic military training. A binary logistic regression could be constructed wherein the onset of the electromyographic activity of the vastus medialis obliquus and vastus lateralis was withheld in the model. The most optimal cutoff value, which is based on the receiver operating characteristic curve, is a timing difference of -0.67 milliseconds (vastus medialis obliquus - vastus lateralis). The area under the receiver operating characteristic curve is considered as fair (0.68). Conclusion: Delayed onset of electromyographic activity of the vastus medialis obliquus - vastus lateralis is one of the contributing risk factors to the development of patellofemoral pain

Computed tomographic analysis of the quality of trunk muscles in asymptomatic and symptomatic lumbar discectomy patients

Abstract Background No consensus exists on how rehabilitation programs for lumbar discectomy patients with persistent complaints after surgery should be composed. A better understanding of normal and abnormal postoperative trunk muscle condition might help direct the treatment goals. Methods A three-dimensional CT scan of the lumbar spine was obtained in 18 symptomatic and 18 asymptomatic patients who had undergone a lumbar discectomy 42 months to 83 months (median 63 months) previously. The psoas muscle (PS), the paraspinal muscle mass (PA) and the multifidus muscle (MF) were outlined at the L3, L4 and L5 level. Of these muscles, fat free Cross Sectional Area (CSA) and fat CSA were determined. CSA of the lumbar erector spinae (LES = longissimus thoracis + iliocostalis lumborum) was calculated by subtracting MF CSA from PA CSA. Mean muscle CSA of the left and right sides was calculated at each level. To normalize the data for interpersonal comparison, the mean CSA was divided by the CSA of the L3 vertebral body (mCSA = normalized fat-free muscle CSA; fCSA = normalized fat CSA). Differences in CSA between the pain group and the pain free group were examined using a General Linear Model (GLM). Three levels were examined to investigate the possible role of the level of operation. Results In lumbar discectomy patients with pain, the mCSA of the MF was significantly smaller than in pain-free subjects (p = 0.009) independently of the level. The mCSA of the LES was significantly smaller in pain patients, but only on the L3 slice (p = 0.018). No significant difference in mCSA of the PS was found between pain patients and pain-free patients (p = 0.462). The fCSA of the MF (p = 0.186) and of the LES (p = 0.256) were not significantly different between both populations. However, the fCSA of the PS was significantly larger in pain patients than in pain-free patients. (p = 0.012). The level of operation was never a significant factor. Conclusions CT comparison of MF, LES and PS muscle condition between lumbar discectomy patients without pain and patients with protracted postoperative pain showed a smaller fat-free muscle CSA of the MF at all levels examined, a smaller fat- free muscle CSA of the LES at the L3 level, and more fat in the PS in patients with pain. The level of operation was not found to be of importance. The present results suggest a general lumbar muscle dysfunction in the pain group, in particular of the deep stabilizing muscle system.</p

Toilet drain water as a potential source of hospital room-to-room transmission of carbapenemase-producing Klebsiella pneumoniae

Background: Carbapenemase-producing Enterobacterales (CPE) have rapidly emerged in Europe, being responsible for nosocomial outbreaks. Aim: Following an outbreak in the burn unit of Ghent University Hospital, we investigated whether CPE can spread between toilets through drain water and therefrom be transmitted to patients. Methods: In 2017, the burn centre of our hospital experienced an outbreak of OXA-48-producing Klebsiella pneumoniae that affected five patients staying in three different rooms. Environmental samples were collected from the sink, shower, shower stretcher, hand rail of the bed, nursing carts, toilets, and drain water to explore a common source. Whole-genome sequencing and phylogenetic analysis was performed on K. pneumoniae outbreak isolates and two random K. pneumoniae isolates. Findings: OXA-48-producing K. pneumoniae was detected in toilet water in four out of six rooms and drain water between two rooms. The strain persisted in two out of six rooms after two months of daily disinfection with bleach. All outbreak isolates belonged to sequence type (ST) 15 and showed isogenicity (<15 allele differences). This suggests that the strain may have spread between rooms by drain water. Unexpectedly, one random isolate obtained from a patient who became colonized while residing at the geriatric ward clustered with the outbreak isolates, suggesting the outbreak to be larger than expected. Daily application of bleach tended to be superior to acetic acid to disinfect toilet water; however, disinfection did not completely prevent the presence of carbapenemase-producing K. pneumoniae in toilet water. Conclusion: Toilet drain water may be a potential source of hospital room-to-room transmission of carbapenemase-producing K. pneumoniae