[Ultrasound-guided needle-knife release of transverse carpal ligament for the treatment of fibrosis in carpal tunnel syndrome].

Abstract

Objective: To explore effects of ultrasound-guided needle-knife dissection of transverse carpal ligament on morphology, function and fibrosis level of the median nerve and transverse carpal ligament in rabbits with carpal tunnel syndrome.

Methods: Forty-eight clean-grad male New Zealand rabbits aged 5 to 6 months were selected, with a body weight of (3.0±0.5) kg. They were randomly divided into blank group, model group, ultrasound group, non-ultrasound group, pseudo-needle knife group, and hormone group, with 8 rabbits in each group. All groups except blank group were underwent modeling performed by injecting 10% glucose solution into wrist canal. The modeling and intervention were conducted once every 7 days. After 4 rounds of modeling, except for control group and model group, all other groups were received intervention for 4 times. Ultrasound group was performed needle-knife dissection of wrist transverse ligament under ultrasound guidance. Non-ultrasound group was adopted the same surgical procedure as ultrasound group but without using ultrasound. The sham needle-knife group was used ultrasound guidance to reach wrist transverse ligament but did not perform dissection. The hormone group injected glucocorticoids into wrist transverse ligament and the median nerve under ultrasound guidance. At 30 days after intervention, ultrasound was used to measure the thickness of palmar ligament and median nerve;electromyography was employed to measure the conduction velocity, latency and action potential of median nerve to assess function of the median nerve;the transverse ligament of wrist and the median nerve were subjected to hematorglineosin(HE) staining to observe tissue morphology. The concentrations of transforming growth factor β1(TGF β1), connective tissue growth factor(CTGF), and collagen typeⅠ(ColⅠ) and collagen type Ⅲ(Col Ⅲ) were detected by enzyme-linked immunosorbent assay (ELISA) to observe the concentrations of fibrosis-related factors. Immunofluorescence was used to detect the relative fluorescence intensity of TGFβ1 in the tissues of the median nerve and the transverse ligament of wrist.

Results: Compared with model group, the thickness of the median nerve and palmar ligament in ultrasound group, non-ultrasound group and hormone group decreased, and the differences were statistically significant(P<0.05). In terms of electrophysiological examination, ultrasound group, non-ultrasound group and hormone group all showed improvements in the conduction velocity, latency and action potential of the median nerve, and the differences were statistically significant compared with model group(P<0.05). In terms of Elisa test, the concentrations of TGFβ1 in ultrasound group, non-ultrasound group and hormone group were lower than those in model group(P<0.05). The CTGF level in ultrasound group was decreased, and the difference was statistically significant(P<0.05). The concentrations of ColⅠand Col Ⅲ in ultrasound group and non-ultrasound group were both decreased (P<0.05). In terms of immunofluorescence observation, there was no statistically significant difference in fluorescence intensity among all groups (P>0.05). The HE staining fibers in ultrasound group were relatively neatly arranged, and the degree of nerve edema and vacuolation was lower.

Conclusion: The use of needle knife to loosen transverse ligament of wrist could reduce the thickness of transverse ligament and the median nerve, and restore function of the median nerve. The mechanism may be related to inhibition of expression of TGFβ1-CTGF pathway in the wrist canal, the reduction of collagen protein deposition of ColⅠ and Col Ⅲ, and decrease of degree of tissue fibrosis in wrist canal. The overall therapeutic effect of needle knife treatment under ultrasound guidance is superior to that of non-ultrasound guidance and hormone injection treatment.