TY - JOUR
T1 - Median nerve deformation and displacement in the carpal tunnel during index finger and thumb motion
AU - Van Doesburg, Margriet H.M.
AU - Yoshii, Yuichi
AU - Villarraga, Hector R.
AU - Henderson, Jacqueline
AU - Cha, Stephen S.
AU - An, Kai Nan
AU - Amadio, Peter C.
PY - 2010/10
Y1 - 2010/10
N2 - The purpose of this study was to investigate the deformation and displacement of the normal median nerve in the carpal tunnel during index finger and thumb motion, using ultrasound. Thirty wrists from 15 asymptomatic volunteers were evaluated. Cross-sectional images during motion from full extension to flexion of the index finger and thumb were recorded. On the initial and final frames, the median nerve, flexor pollicis longus (FPL), and index finger flexor digitorum superficialis (FDS) tendons were outlined. Coordinate data were recorded and median nerve cross-sectional area, perimeter, aspect ratio of the minimal-enclosing rectangle, and circularity in extension and flexion positions were calculated. During index finger flexion, the tendon moves volarly while the nerve moves radially. With thumb flexion, the tendon moves volarly, but the median nerve moves toward the ulnar side. In both motions, the area and perimeter of the median nerve in flexion were smaller than in extension. Thus, during index finger or thumb flexion, the median nerve in a healthy human subject shifts away from the index finger FDS and FPL tendons while being compressed between the tendons and the flexor retinaculumin the carpal tunnel. We are planning to compare these data with measurements in patients with carpal tunnel syndrome (CTS) and believe that these parameters may be useful tools for the assessment of CTS and carpal tunnel mechanics with ultrasound in the future.
AB - The purpose of this study was to investigate the deformation and displacement of the normal median nerve in the carpal tunnel during index finger and thumb motion, using ultrasound. Thirty wrists from 15 asymptomatic volunteers were evaluated. Cross-sectional images during motion from full extension to flexion of the index finger and thumb were recorded. On the initial and final frames, the median nerve, flexor pollicis longus (FPL), and index finger flexor digitorum superficialis (FDS) tendons were outlined. Coordinate data were recorded and median nerve cross-sectional area, perimeter, aspect ratio of the minimal-enclosing rectangle, and circularity in extension and flexion positions were calculated. During index finger flexion, the tendon moves volarly while the nerve moves radially. With thumb flexion, the tendon moves volarly, but the median nerve moves toward the ulnar side. In both motions, the area and perimeter of the median nerve in flexion were smaller than in extension. Thus, during index finger or thumb flexion, the median nerve in a healthy human subject shifts away from the index finger FDS and FPL tendons while being compressed between the tendons and the flexor retinaculumin the carpal tunnel. We are planning to compare these data with measurements in patients with carpal tunnel syndrome (CTS) and believe that these parameters may be useful tools for the assessment of CTS and carpal tunnel mechanics with ultrasound in the future.
KW - Carpal tunnel
KW - Deformation
KW - Median nerve
KW - Motion
KW - Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=77957202561&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77957202561&partnerID=8YFLogxK
U2 - 10.1002/jor.21131
DO - 10.1002/jor.21131
M3 - Article
C2 - 20225286
AN - SCOPUS:77957202561
SN - 0736-0266
VL - 28
SP - 1387
EP - 1390
JO - Journal of Orthopaedic Research
JF - Journal of Orthopaedic Research
IS - 10
ER -