Relationship between ultrasonographic hand muscle thickness measurements and muscle strength following median or ulnar nerve reconstruction

Introduction The aim of this study was to assess the relationship between ultrasonographic hand muscle thickness measurements and hand muscle strength in patients who underwent median or ulnar nerve reconstruction. Methods In this prospective, cross-sectional study, intrinsic hand muscle thicknesses were measured using ultrasound with a 4- to 13-MHz linear-array probe. Measurements of hand strength were performed using a dynamometer and a pinchmeter. Results In the median nerve group (n = 11), a moderate correlation (r = 0.694; P = .018) was observed between lateral pinch strength and transverse thenar thickness. In the ulnar nerve group (n = 11), longitudinal thenar thickness below the flexor pollicis longus tendon was moderate to highly correlated with pinch and handgrip strengths (r = 0.726-0.893; P < .05); whole transverse thenar thickness was moderate to highly correlated with pinch strengths (r = 0.724-0.836; P < .05). Discussion Sonographic measurements of intrinsic hand muscle thickness may be a useful tool for the assessment and follow-up of patients with median or ulnar nerve injury.