Determining the Short- to Medium-term Outcome After Minimally Invasive Sonography Guided Release of the Carpal Tunnel Compared to Standard-of-care Open and Endoscopic Techniques: a Randomized Controlled Superiority Trial With an Internal Pilot-phase

Carpal tunnel syndrome (CTS) is the most common peripheral nerve compression disorder encountered in hand surgery. It affects a broad demographic, from young women (often linked to pregnancy and breastfeeding) and young men involved in manual labor, to elderly individuals. The condition causes pain, numbness, and functional impairment in the hand, which can progress to permanent disability if untreated. Typically, conservative treatment (e.g., night splints, corticosteroid injections) is the first step. However, when symptoms persist, surgical decompression of the median nerve becomes necessary.

The current gold standard for surgical treatment of CTS is open carpal tunnel release (OCTR). This involves making a 2-5 cm incision in the palm and cutting the transverse carpal ligament under direct vision. While effective in relieving nerve compression, this approach creates a scar in the load-bearing area of the palm, which can lead to prolonged post-operative pain, delayed wound healing, reduced grip strength, extended rehabilitation time and limitations in early hand use.

To address some of these drawbacks, endoscopic carpal tunnel release (ECTR) was developed. This technique uses a smaller incision at the wrist and a camera system to visualize and divide the ligament. While less invasive than OCTR, ECTR still involves an incision, and significant scar tissue may still develop, especially internally.

Both techniques require postoperative wound care, stitch removal, and carry risks of complications such as nerve or tendon injury, infection, or incomplete release. Additionally, these methods often result in delays in returning to work and daily activities, particularly burdensome for patients in physically demanding jobs.

In recent years, a novel percutaneous ultrasound-guided technique, known as thread carpal tunnel release (TCTR), has been introduced. This method uses two small puncture sites instead of incisions. Under real-time ultrasound guidance, a suture loop is passed around the transverse carpal ligament, which is then divided using a sawing motion. This technique bears several advantages including absence of external scar, reduced postoperative pain, no requirement for stitch removal, potential faster recovery allowing earlier return to normal function, daily activities and work.