Ultrasonographic quantification of intrinsic hand muscle cross-sectional area; reliability and validity for predicting muscle strength.

OBJECTIVE: To investigate whether ultrasonographic measurement of the cross-sectional area (CSA) of the intrinsic hand muscles can be used to predict muscle strength in a valid and reliable manner, and to determine if this method can be used for follow-up of patients with peripheral nerve injury between the wrist and elbow. DESIGN: Repeated-measures cross-sectional study. SETTING: Clinical and academic hospital. PARTICIPANTS: Healthy adults (n=31) and patients with ulnar and median nerve injuries (n=16) between the wrist and elbow who were visiting the Erasmus Medical Center or Maasstad Hospital were included in the study (N=47). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Correlation between measured muscle CSA and strength and assessment of inter- and intrarater reliability. Ultrasound and strength measurements of the intrinsic hand muscles were conducted bilaterally. To establish validity, the CSA of 4 muscles (abductor digiti minimi, first dorsal interosseus, abductor pollicis brevis, opponens pollicis) was compared with strength measurements of the same muscles conducted with the Rotterdam Intrinsic Hand Myometer. Repeated measures were conducted to assess inter- and intrarater reliability. RESULTS: The assessed CSA strongly correlated with strength measurements, with correlations ranging from 0.82 to 0.93 in healthy volunteers and from 0.63 to 0.94 in patients. Test-retest reliability showed excellent intrarater reliability (intraclass correlation coefficient range, 0.99-1.00) in patients and volunteers and good interrater reliability (intraclass correlation coefficient range, 0.88-0.95) in healthy volunteers. CONCLUSIONS: We found that ultrasound is a valid and reliable method to assess the CSA of specific muscles in the hand. Therefore, this technique could be useful to monitor muscle reinnervation in patients suffering from peripheral nerve injury as a valuable addition to strength dynamometers.

The effect of stem cells in bridging peripheral nerve defects: a meta-analysis.

UNLABELLED: OBJECT.: For decades the gold standard for reconstructing a large peripheral nerve defect has been, and remains, the nerve autograft. Alternatives to the nerve autograft include biological conduits and vessels. Adding stem cells in the lumen of a nerve conduit has been the subject of multiple studies. The purpose of the present meta-analysis was to summarize animal experimental studies on the effect of stem cells as a luminal additive when reconstructing a peripheral nerve defect with a nerve graft. METHODS: A literature search of the MEDLINE and Embase databases was performed from inception to April 2012, searching for animal experiments on peripheral nerve reconstruction models in which a nerve conduit was used with and without the support of 3 different types of stem cells. Stem cells were analyzed according to their origin: bone marrow, adipose tissue, and other origins. Included studies had consistent outcome measurements: walking track analysis, muscle mass ratio, and electrophysiology. RESULTS: Forty-four studies were included in the final analysis. Forest plots of the 3 outcome measurements (walking track analysis, muscle mass ratio, and electrophysiology) showed positive effects of stem cells on the regeneration of peripheral nerves at different time points. Almost all comparisons showed significant differences for all 3 stem cells groups compared with a control group in which stem cells were not used. CONCLUSIONS: The present report systematically analyzed the different studies that used stem cells as a luminal additive when bridging a large peripheral nerve defect. All 3 different stem cell groups showed a beneficial effect when used in the reconstruction compared with control groups in which stem cells were not used.