Ultrasound‑Guided Release for Carpal Tunnel & Trigger Finger – Now at Lecheng

I still remember the first time a patient showed me her hands. She was a 52-year-old seamstress who had spent three decades behind a sewing machine in a Guangdong factory. Her right hand was almost frozen – the middle finger curled inward like a claw, refusing to straighten unless she pried it open with her other hand. And her wrist? She described it as “a vise tightening” every night at 2 a.m., with numbness radiating into her thumb and index finger, waking her from sleep. She had tried splints, steroid injections, and anti‑inflammatory drugs. Nothing worked. “Doctor,” she asked, “do I have to live with this for the rest of my life?”

I did not have a good answer then. But I have one now.

On March 14, 2025, the Ruijin Hospital Hainan Hospital (Rui Jin Hainan Hospital) – located in the Boao Lecheng International Medical Tourism Pilot Zone – became the first hospital in China to introduce two advanced minimally invasive devices: the **Ultrasound‑Guided Release Knife Kit (Carpal Tunnel)** and the **Ultrasound‑Guided Release Knife Kit (Trigger Finger)**. These are not just incremental improvements. They represent a genuine paradigm shift in how we treat two of the most common – and most disabling – hand conditions in the world.

Let me explain these conditions the way I explain them to my patients, because the names alone can be intimidating.

Carpal tunnel syndrome (CTS) occurs when the median nerve – which runs from your forearm into your hand through a narrow passageway in the wrist called the carpal tunnel – becomes compressed. The classic symptoms are numbness and tingling in the thumb, index, middle, and ring fingers (sparing the little finger), especially at night. Over time, grip strength weakens, and the muscles at the base of the thumb may shrink. In severe cases, patients drop objects, struggle to button shirts, and lose fine motor control. The cause is often repetitive wrist motion, but it can also be associated with pregnancy, diabetes, hypothyroidism, rheumatoid arthritis, and obesity.

Trigger finger (stenosing tenosynovitis) affects the flexor tendons that bend your fingers. Normally, each tendon glides smoothly through a tunnel of ligament and bone called the pulley system. When the tendon becomes inflamed or develops a nodule, it gets caught on the pulley – like a rope with a knot trying to pass through a small ring. The finger locks in a bent position and then snaps straight with a painful “pop.” Many of my patients describe it as the feeling of pulling a trigger – hence the name. The ring finger and thumb are most commonly involved, and the condition is often seen in people with diabetes, rheumatoid arthritis, or jobs that require repetitive gripping.

Now, why is China a hotbed for both? There is no single answer, but the data are striking. A 2022 systematic review and meta‑analysis estimated the prevalence of carpal tunnel syndrome in China at approximately 7.8% of the general population – with rates exceeding 15% in workers in manufacturing, assembly lines, and textile industries. Trigger finger, while less systematically studied, is thought to affect nearly 3–5% of the adult population, and its incidence rises sharply after age 50 – exactly when many Chinese workers are still in the labor force.

Why so high? First, China has a massive manufacturing workforce. Millions of people work in electronics assembly, garment production, and packaging – jobs that involve hours of repetitive wrist flexion and grip. Second, the widespread use of smartphones and computers has shifted the epidemiology. I now see teenagers and young adults with “texting thumb” and early CTS – a phenomenon that barely existed a decade ago. Third, diabetes and obesity are rising in China, and both are powerful risk factors for nerve compression and tendon inflammation. Add to that an aging population – more than 260 million Chinese citizens are over age 60 – and you have a perfect storm of hand disability.

For decades, the standard treatments have been either conservative (splinting, steroid injections, activity modification) or surgical (open carpal tunnel release, open trigger finger release). But both have significant drawbacks. Steroid injections provide only temporary relief. Open surgery requires a scalpel incision, often leaves a tender scar, carries risks of nerve injury and infection, and demands weeks of recovery during which patients cannot work. For the seamstress I mentioned earlier, losing three weeks of income was simply not an option – so she lived with the pain instead.

That is where the new devices come in.

Both devices are manufactured by **Sonex Health**, a US‑based medical technology company focused on minimally invasive hand and upper extremity procedures. The principle is elegantly simple: instead of a long open incision, the surgeon uses real‑time ultrasound imaging to visualize the compressed nerve (in CTS) or the thickened tendon pulley (in trigger finger) through the skin. Then, a purpose‑designed, single‑use knife is inserted through a tiny puncture – typically less than 3 millimeters – and the release is performed under direct ultrasound guidance. The entire procedure takes less than 10 minutes and is done in an office‑based procedure room under local anesthesia. There is no tourniquet, no operating room, no overnight stay, and no visible scar.

For carpal tunnel syndrome, the ultrasound‑guided release knife kit allows the surgeon to precisely cut the transverse carpal ligament – the roof of the tunnel – while continuously visualizing the median nerve on the ultrasound screen. This real‑time visualization is the game‑changer: the surgeon can see exactly where the blade is, how deep it is cutting, and – crucially – ensure the blade stays millimeters away from the nerve. Traditional open release requires a 2–3 cm incision in the palm, which cuts through skin, subcutaneous tissue, and palmar fascia, leaving many patients with pillar pain (tenderness on the sides of the palm) for months.

For trigger finger, the ultrasound‑guided release knife kit targets the A1 pulley – the ligament that forms the first “ring” around the flexor tendon at the base of the finger. Under ultrasound guidance, the knife is advanced to the pulley and the blade is deployed to cut it longitudinally. The locked tendon is immediately freed. Again, the incision is less than 3 mm, and because the surrounding tissues are preserved, recovery is dramatically faster than traditional open surgery, which involves a 1–2 cm incision in the palm and often requires sutures.

The advantages over traditional therapy are not marginal; they are transformative. Let me list them as I would to a patient:

• Same‑day procedure: In and out of the clinic in under an hour. No hospital admission.
• No sutures, no scar: The puncture site heals with a barely visible mark.
• Local anesthesia only: No sedation, no general anesthesia risks.
• Immediate return to activities: Most patients can drive, type, and perform light tasks the next day. Heavy gripping is typically allowed within two weeks, compared to six weeks after open surgery.
• Reduced complication profile: Because the incision is tiny, the risks of infection, nerve injury, and painful scarring are significantly lower than in open surgery.
• Ultrasound guidance ensures precision: The surgeon is not operating “blind.” The nerve is visible throughout the procedure, which is a major safety upgrade from even the best‑performed blind or semi‑blind percutaneous techniques.

Multiple clinical studies have validated this approach. For CTS, a prospective multi‑center trial comparing ultrasound‑guided release with traditional open release showed equivalent efficacy in symptom relief and nerve function improvement, but with significantly less postoperative pain, faster return to work, and higher patient satisfaction scores. For trigger finger, large case series have reported success rates above 95% with essentially zero major complications.

As a clinician, I do not recommend a device simply because it is novel. I recommend it because the evidence and regulatory oversight support its safety. The Sonex Health ultrasound‑guided release knife kits have received regulatory clearances from the world’s most stringent health authorities:

• FDA (USA): Both the carpal tunnel release kit and the trigger finger release kit have received 510(k) clearance from the U.S. Food and Drug Administration, which means they have been shown to be substantially equivalent to legally marketed predicate devices with a strong safety record.
• CE Mark (European Union): The devices carry the CE mark, indicating conformity with the health, safety, and environmental protection standards for products sold within the European Economic Area. The CE certification process for Class IIa medical devices involves rigorous assessment of clinical performance and risk management.
• Health Canada License: The devices are also licensed by Health Canada, another reference regulator.

In addition, the manufacturer follows ISO 13485:2016 standards for quality management systems – the gold standard for medical device manufacturing. Each kit is single‑use, sterile, and individually packaged, eliminating any risk of cross‑contamination.

For my practice at Ruijin Hainan Hospital, this regulatory pedigree provides the assurance I need. But equally important is the clinical experience: as of 2025, more than 50,000 patients worldwide have been treated with these ultrasound‑guided release devices, with published outcomes showing high efficacy and an extremely low complication rate. The devices are now standard of care in many leading hand surgery centers across North America, Europe, and Australia.

And now, they are available in China – right here, in Lecheng.

China’s National Medical Products Administration (NMPA) has not yet fully approved these devices for nationwide use. The traditional approval process for a novel Class III medical device can take three to five years or more. But the Boao Lecheng Pilot Zone operates under a special policy: “first‑pilot, first‑use.” If a medical device or drug has already been approved by a major international regulatory body (FDA, CE, PMDA, etc.), and if it addresses an unmet clinical need in China, Lecheng can authorize its limited clinical application at designated hospitals within the zone – years before it becomes available in the rest of the country.

Ruijin Hospital Hainan Hospital – the Hainan branch of Shanghai’s prestigious Ruijin Hospital affiliated with Shanghai Jiao Tong University School of Medicine – is one of Lecheng’s flagship institutions. The hospital has a dedicated hand surgery and ultrasound‑guided intervention team, trained directly by Sonex Health proctors. The facility also meets all the requirements for ultrasound‑guided procedures: high‑resolution musculoskeletal ultrasound machines, procedure rooms with full resuscitation equipment, and an experienced postoperative follow‑up system.

For patients living outside Hainan, the process is straightforward: you send your medical records (including clinical history, physical examination findings, and electrodiagnostic studies if available) to the hospital. The hand surgery team reviews your case and determines if you are a candidate. If you are, you travel to Lecheng for a one‑day procedure and a brief follow‑up before returning home. In most cases, you do not even need to take time off work beyond the procedure day.