OBJECTIVE A thorough understanding of anatomy is critical for successful carpal tunnel release. S... more OBJECTIVE A thorough understanding of anatomy is critical for successful carpal tunnel release. Several texts depict the median nerve (MN) as taking a course parallel to the long axis of the forearm (LAF). The authors report on their attempt to formally assess the course of the MN as it travels to the carpal tunnel in the distal wrist and discuss its potential clinical significance. METHODS The width of the wrist, the distance from the radial wrist to the MN, and the distance from the distal volar wrist crease to the point where the MN emerges between the flexor carpi radialis (FCR) tendon and the flexor digitorum superficialis (FDS) tendons were recorded during cadaveric dissection of 76 wrist specimens. The presence or absence of palmaris longus was documented. Finally, the angles between the MN and FCR tendon and between the MN and the LAF were measured using ImageJ. RESULTS The relative position of the MN at the distal wrist crease, as determined by the ratio of the distance from the MN to the radial wrist divided by wrist width, revealed a mean value of 0.48, indicating that the nerve was usually located just radial to midline. The mean distance between the distal wrist crease and the MN's emergence was 34.6 mm. The mean angle between the MN and the FCR tendon was 14.1°. The angle between the MN and the LAF had a mean value of 8.8° (range 0.0°-32.2°). The nerve was parallel to the LAF in only 10.7% of the studied wrists. Palmaris longus was absent in 14 (18.4%) of the 76 wrists. CONCLUSIONS The MN takes an angular approach to the carpal tunnel in the distal wrist in the vast majority of cases. This newly described finding will be useful to both clinicians and anatomists.
Case reports and case control studies have suggested an association between chiropractic neck man... more Case reports and case control studies have suggested an association between chiropractic neck manipulation and cervical artery dissection (CAD), but a causal relationship has not been established. We evaluated the evidence related to this topic by performing a systematic review and meta-analysis of published data on chiropractic manipulation and CAD. Search terms were entered into standard search engines in a systematic fashion. The articles were reviewed by study authors, graded independently for class of evidence, and combined in a meta-analysis. The total body of evidence was evaluated according to GRADE criteria. Our search yielded 253 articles. We identified two class II and four class III studies. There were no discrepancies among article ratings (i.e., kappa=1). The meta-analysis revealed a small association between chiropractic care and dissection (OR 1.74, 95% CI 1.26-2.41). The quality of the body of evidence according to GRADE criteria was "very low." The qualit...
Case reports, case series and case control studies have looked at the use of phrenic nerve stimul... more Case reports, case series and case control studies have looked at the use of phrenic nerve stimulators in the setting of high spinal cord injuries and central hypoventilation syndromes dating back to the 1980s. We evaluated the evidence related to this topic by performing a systematic review of the published literature. Search terms "phrenic nerve stimulation," "phrenic nerve and spinal cord injury," and "phrenic nerve and central hypoventilation" were entered into standard search engines in a systematic fashion. Articles were reviewed by two study authors and graded independently for class of evidence according to published guidelines. The published evidence was reviewed, and the overall body of evidence was evaluated using the grading of recommendations, assesment, development and evaluations (GRADE) criteria Balshem et al. (J Clin Epidemiol 64:401-406, 2011). Our initial search yielded 420 articles. There were no class I, II, or III studies. There were 18 relevant class IV articles. There were no discrepancies among article ratings (i.e., kappa = 1). A meta-analysis could not be performed due to the low quality of the available evidence. The overall quality of the body of evidence was evaluated using GRADE criteria and fell within the "very poor" category. The quality of the published literature for phrenic nerve stimulation is poor. Our review of the literature suggests that phrenic nerve stimulation is a safe and effective option for decreasing ventilator dependence in high spinal cord injuries and central hypoventilation; however, we are left with critical questions that provide crucial directions for future studies.
OBJECTIVE A thorough understanding of anatomy is critical for successful carpal tunnel release. S... more OBJECTIVE A thorough understanding of anatomy is critical for successful carpal tunnel release. Several texts depict the median nerve (MN) as taking a course parallel to the long axis of the forearm (LAF). The authors report on their attempt to formally assess the course of the MN as it travels to the carpal tunnel in the distal wrist and discuss its potential clinical significance. METHODS The width of the wrist, the distance from the radial wrist to the MN, and the distance from the distal volar wrist crease to the point where the MN emerges between the flexor carpi radialis (FCR) tendon and the flexor digitorum superficialis (FDS) tendons were recorded during cadaveric dissection of 76 wrist specimens. The presence or absence of palmaris longus was documented. Finally, the angles between the MN and FCR tendon and between the MN and the LAF were measured using ImageJ. RESULTS The relative position of the MN at the distal wrist crease, as determined by the ratio of the distance from the MN to the radial wrist divided by wrist width, revealed a mean value of 0.48, indicating that the nerve was usually located just radial to midline. The mean distance between the distal wrist crease and the MN's emergence was 34.6 mm. The mean angle between the MN and the FCR tendon was 14.1°. The angle between the MN and the LAF had a mean value of 8.8° (range 0.0°-32.2°). The nerve was parallel to the LAF in only 10.7% of the studied wrists. Palmaris longus was absent in 14 (18.4%) of the 76 wrists. CONCLUSIONS The MN takes an angular approach to the carpal tunnel in the distal wrist in the vast majority of cases. This newly described finding will be useful to both clinicians and anatomists.
Case reports and case control studies have suggested an association between chiropractic neck man... more Case reports and case control studies have suggested an association between chiropractic neck manipulation and cervical artery dissection (CAD), but a causal relationship has not been established. We evaluated the evidence related to this topic by performing a systematic review and meta-analysis of published data on chiropractic manipulation and CAD. Search terms were entered into standard search engines in a systematic fashion. The articles were reviewed by study authors, graded independently for class of evidence, and combined in a meta-analysis. The total body of evidence was evaluated according to GRADE criteria. Our search yielded 253 articles. We identified two class II and four class III studies. There were no discrepancies among article ratings (i.e., kappa=1). The meta-analysis revealed a small association between chiropractic care and dissection (OR 1.74, 95% CI 1.26-2.41). The quality of the body of evidence according to GRADE criteria was "very low." The qualit...
Case reports, case series and case control studies have looked at the use of phrenic nerve stimul... more Case reports, case series and case control studies have looked at the use of phrenic nerve stimulators in the setting of high spinal cord injuries and central hypoventilation syndromes dating back to the 1980s. We evaluated the evidence related to this topic by performing a systematic review of the published literature. Search terms "phrenic nerve stimulation," "phrenic nerve and spinal cord injury," and "phrenic nerve and central hypoventilation" were entered into standard search engines in a systematic fashion. Articles were reviewed by two study authors and graded independently for class of evidence according to published guidelines. The published evidence was reviewed, and the overall body of evidence was evaluated using the grading of recommendations, assesment, development and evaluations (GRADE) criteria Balshem et al. (J Clin Epidemiol 64:401-406, 2011). Our initial search yielded 420 articles. There were no class I, II, or III studies. There were 18 relevant class IV articles. There were no discrepancies among article ratings (i.e., kappa = 1). A meta-analysis could not be performed due to the low quality of the available evidence. The overall quality of the body of evidence was evaluated using GRADE criteria and fell within the "very poor" category. The quality of the published literature for phrenic nerve stimulation is poor. Our review of the literature suggests that phrenic nerve stimulation is a safe and effective option for decreasing ventilator dependence in high spinal cord injuries and central hypoventilation; however, we are left with critical questions that provide crucial directions for future studies.
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