Sonographic Changes After Ultrasound‐Guided Release of the Transverse Carpal Ligament: A Case Report

Abstract

Carpal tunnel syndrome is the most common entrapment neuropathy, resulting in 500,000 carpal tunnel release (CTR) surgeries and a total cost of more than 2 billion dollars annually in the United States. Although initially performed via a large (3-5 cm) palmar incision, CTR techniques have continually evolved to reduce incision size, recovery times, postoperative pain, and improve cosmesis and clinical outcomes. More recently, multiple authors have reported excellent results after ultrasound-guided carpal tunnel release (USCTR) using a variety of techniques, and one prospective randomized trial reported faster recovery after USCTR compared with traditional mini-open CTR. However, there is a paucity of data with respect to changes in the median nerve after USCTR. This case report presents the functional outcomes and pre- and postprocedure ultrasound images of a patient after USCTR with 3-month follow-up. LEVEL OF EVIDENCE: V.

Clinical Results of Ultrasound‐Guided Carpal Tunnel Release Performed by a Primary Care Sports Medicine Physician

“…In general, all procedures were performed as previously described . After completing informed consent and a procedural time out, the patient was placed in a supine position with the shoulder abducted, the elbow flexed, and the forearm supinated on an arm board in the direct line of sight of the US machine (Figure ).…”

“…In June 2017, he started using the SX‐One MicroKnife (Sonex Health, Inc., Rochester, MN) to perform USCTR. Unlike the MANOS device, the SX‐One MicroKnife uses inflatable balloons to displace sensitive anatomic structures away from the centrally located, retractable hook knife (Figure ) . Once the balloons are activated, the cutting knife is deployed to cut the TCL distal to proximal.…”

Ultrasound (US) Changes in the Median Nerve Cross‐Sectional Area After Microinvasive US‐Guided Carpal Tunnel Release

“…All microinvasive US‐guided CTR procedures were performed by the primary author in the office using local anesthesia (WALANT [wide‐awake, local anesthesia, no tourniquet] technique), an HS60 US machine and a 4–18‐MHz linear transducer (Samsung, Seoul, Korea), and an SX‐One MicroKnife (Sonex Health, Inc, Rochester, MN) . The technique has been detailed elsewhere . In brief, after identification of relevant anatomic landmarks, US visualization was used to hydrodissect the median nerve with 7 to 8 mL of 5% dextrose and to administer local anesthesia by injecting approximately 7 mL of 1% lidocaine into the subcutaneous tissues and carpal tunnel.…”

“…Although most CTRs in the United States have been traditionally performed by using open or endoscopic approaches, advances in US technology have promoted the development of US‐guided techniques to transect the TCL (ie, US‐guided CTR). To date, more than 640 cases of US‐guided CTR have been reported in the peer‐reviewed literature, with a clinical success rate of greater than 95%, no major complications, and in some studies, superior early outcomes compared to traditional open CTR . However, only 3 previous publications evaluated the median nerve after US‐guided CTR.…”

“…Petrover et al used magnetic resonance imaging to evaluate the CSA of the median nerve in the distal tunnel (ie, at the hamate) in 129 patients 1 month after US‐guided CTR but did not measure the proximal median nerve CSA. More recently, Latzka et al reported a reduction in the US‐determined proximal median nerve CSA from 24 to 16 mm 2 at 1 month and 14 mm 2 at 3 months in a single patient after US‐guided CTR. In summary, to date, only a single case report has described the use of US to examine the proximal median nerve CSA before and after US‐guided CTR in which the TCL was transected similar to open and endoscopic CTR.…”