Abstract

Purpose: The purpose of this study was to assess change and correlation of median nerve circumference, abductor pollicis brevis muscle thickness, and hand grip strength post carpal tunnel release.

Subject: A 47-years-old woman post open carpal tunnel release was immobilized in a neutral wrist splint for six weeks then began a progressive two-month rehabilitation program supervised by a physical therapist.

Methods: Both transverse median nerve circumference and transverse abductor pollicis brevis muscle thickness were assessed using rehabilitative ultrasound imaging and grip strength was measured utilizing a hand-held dynamometer preoperatively and every four weeks postoperatively for nine months.

Data analysis: Repeated measures analysis of variance evaluated median nerve circumference, abductor pollicis brevis muscle thickness, and grip while Pearson correlation coefficient measured their relationships.

Results: Median nerve circumference showed significant reduction preoperative to month 9 (1 mm to 0.64 mm, p = 0.018), month 2 to 5 (1.02 mm to 0.92mm; p = 0.034), and month 3 to 6 (1.1 mm to 0.92 mm; p = 0.037). Abductor pollicis brevis muscle thickness significantly increased every month (1.29 cm to 1.43 cm, p = 0.001) except month 1 and 4. Grip significantly decreased preoperative to month 1 (20.87 kg to 16.33 kg, p = 0.044) but significantly increased through month 8 (20.87 kg to 25.40 kg, p = 0.031). Large immediate postoperative median nerve largely correlated with low grip strength (r(3)= -0.866). At month 8, small median nerve largely correlated with high grip strength (r(3)= -0.5) and the large correlation between small median nerve and large abductor pollicis brevis muscle thickness was significant (r(3)= -0.952, p = 0.012).

Conclusions: Slightly increased postoperative median nerve circumference and healing influenced grip and abductor pollicis brevis muscle thickness initially but progressively improved over nine months. Gradual muscle muscle thickness hypertrophy and recovery of grip strength post carpal tunnel release appears directly related to progressive decrease median nerve circumference.

Clinical Relevance: The patient returned to full activity and work function at 8 weeks post carpal tunnel release but continued to exhibit strength and thenar muscle deficits that correlated to postoperative median nerve inflammation and recovery that persisted into the eighth month.

Keywords: Carpal Tunnel Release; Median Nerve; Thenar Muscle Thickness; Grip Strength; Ultrasound Imaging

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Citation

Citation: Tony Boucher. “Ultrasonographic Median Nerve Circumference, Thenar Muscle Thickness, and Grip Strength Change and Correlation After Carpal Tunnel Release: Single Case Design".Acta Scientific Orthopaedics 4.12 (2021): 04-08.

Copyright

Copyright: © 2021 Tony Boucher. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.