Carpal Tunnel Syndrome (CTS)

Background

Carpal tunnel syndrome (CTS) is a common compressive neuropathy of the upper extremity. The median nerve travels through the carpal tunnel in the wrist and is protected by the transverse carpal ligament. If there is an increase in pressure within the carpal tunnel, the median nerve can get compressed. The median nerve has both sensory and motor functions, it provides feeling to the thumb, index, long, and half of the ring finger, and innervates one of the short muscles of the thumb. CTS can result in pain, numbness, and tingling in the hand but it can also lead to weakness and atrophy of the thumb musculature.

Causes

The median nerve runs in the carpal tunnel along with 9 other tendons. There is a limited amount of room in the tunnel. If the tissues around the tendons (called tenosynovium) become inflamed or thickened, this results in pressure on the median nerve. Pressure on a nerve that provides sensation and motor function can lead to numbness, tingling but also weakness. This condition is usually caused by a combination of factors. Genetics play a role in leading to anatomical variations of the carpal tunnel’s size. Also, certain inflammatory and metabolic conditions can predispose patients to CTS, e.g. autoimmune inflammatory joint conditions such as rheumatoid arthritis.

Symptoms

CTS is a progressive condition that often worsens over time. The initial symptoms include numbness and tingling in the fingertips of the thumb, index, middle and ring finger. Nighttime symptoms (tingling and/or pain) are particularly common, and can wake patients up. As the condition progresses, atrophy (“thinning”) of the thumb muscles may occur. The numbness and weakness can become constant. Dropping objects is also commonly reported by patients as a result. Not infrequently, the pain radiates up the patient’s arm.

Diagnosis & Treatment

The patient's history is critical in making the diagnosis, followed by a physical exam that includes a number of maneuvers such as the Tinel and Phalen tests. Electromyography (EMG, also called “nerve test”) aids in further confirming the condition and locating the site of nerve compression. Dr. Sammy also routinely uses the ultrasound to diagnose the condition. CTS can be treated with a variety of options, depending on its severity.

Nonoperative measures include night splinting, hand therapy, as well as antiinflammatories. The next step in treatment can involve a corticosteroid injection into the carpal tunnel. Surgical release is often considered, depending on the severity of the compression. The procedure involves dividing the transverse carpal ligament to increase room in the carpal canal and relieve pressure on the median nerve. Dr. Sammy performs both open and endoscopic releases, depending on the patient and their individual needs.

Open Carpal Tunnel Release

The open release requires making a short incision in the palm over the carpal tunnel. Through this approach, the median nerve is released with direct visualization of the nerve. The incision is closed with dissolvable stitches. The hand is bandaged leaving the thumb and fingers free. The bandage stays on for 7 days. Immediate movement of the fingers is encouraged to help minimize swelling. Light use of the hand is allowed at 2 weeks. Heavier use at 4 weeks.

Endoscopic Carpal Tunnel Release

This is a minimally-invasive procedure that involves making a small incision along the forearm at the wrist level and advancing a camera into the carpal tunnel. The ligament is released using a special camera-mounted device. The recovery is shorter than that of the traditional open carpal tunnel release. Dissolvable sutures are used. The hand can be used immediately for light activities. Heavier activities after 2 weeks.

This illustration reveals the open versus the endoscopic approach. Although it may appear as though the endoscopic release is the best solution, this is something that Dr. Dowlatshahi will go over with you during the consultation.

This is what it looks like in the operating room when performing the endoscopic release. The camera is inserted through a 1 cm incision at the wrist.

This image shows the view of the transverse carpal ligament from underneath, as the blade is being deployed.