Externally applied force helps reduce bowstring effect of flexors in patients with carpal tunnel release surgery. (April 2022)

• Record Type: Journal Article
• Authors: Lin, Chien-Ju; Chen, Yi-Ching; Chieh, Hsiao-Feng; Jou, I-Ming; Wu, Po-Ting; Lai, Yen-Liang; Lai, Chun-Ta; Kuo, Li-Chieh; Su, Fong-Chin
• Is Part Of: Musculoskeletal science and practice. Volume 58(2022)
• Publication Date: 2022-04
• Subjects: Carpal tunnel syndrome -- Trigger finger -- Prevention; Manipulation (Therapeutics) -- Periodicals; Physical therapy -- Periodicals; Neuromuscular diseases -- Treatment -- Periodicals; Musculoskeletal system -- Diseases -- Periodicals; Manipulation (Therapeutics); Neuromuscular diseases -- Treatment; Physical therapy; Manipulation, Orthopedic; Musculoskeletal Diseases -- therapy; Neuromuscular Diseases -- therapy; Physical Therapy Modalities; Electronic journals; Periodicals; 615.82
• DOI: 10.1016/j.msksp.2022.102517
• Languages: English
• ISSNs: 2468-8630

Abstract

Abstract: Background: Patients with severe carpal tunnel syndrome (CTS) undergo carpal tunnel release (CTR) surgery to alleviate pressure in the carpal tunnel. However, the subsequent lack of the transverse carpal ligament (TCL) causes the bowstring phenomenon of the flexor tendons and increases the potential incidence of trigger finger. Objective: This study aimed to investigate the effects of various compressive forces on the flexor tendon and identify the appropriate force needed to mitigate the bowstring effect of those flexors. Design: Cross-sectional repeated measures comparison. Method: Thirteen CTS patients who underwent CTR surgery were asked to flex the middle finger while applying different external compressive forces, just contact, 4N, and 8N force, over the carpal tunnel. Images of the flexor tendon within the carpal tunnel and at the metacarpal phalangeal (MCP) joint were recorded via ultrasound. Result: Results show that the compression force limited the volar migration of the flexor tendon under maximal voluntary contraction (MVC) conditions. Entrance angles between the flexor tendon and metacarpal bone also decreased as the external compressive force increased. Conclusions: Findings of this study may indicate that applying compression force on the carpal tunnel is useful for CTS patients and can inhibit the volar shift of the flexor digitorum superficialis (FDS) tendon after surgery, which may further prevent trigger finger. Highlights: Compression force limit the volar migration of the flexor tendon. Entrance angles between decreased as the compression force increased. Applying compression force on the carpal tunnel may prevent trigger finger.