Carpal canal syndrome
Carpal canal syndrome is the compression of the median nerve at the level of the wrist, which causes:
- Numbness in the thumb, index, middle and half of the ring finger
- Prurit (itching) and atrophy of the thenar eminence (base of the thumb) in more advanced stages,
- Low strength in grasping objects between the thumb and another finger.
It is the most commonly diagnosed nerve compression in the upper limb.
The most common causes that cause carpal canal syndrome are:
- Repetitive tasks, force, posture, and vibration that overuse the wrist
- Anatomical – narrow carpal canal / presence of muscle fibers at this level, increasing the pressure and the sensation of numbness in the fingers
- The presence of a synovial cyst, which compresses the nerve
- Idiopathic synovitis of the flexor tendons
- Fracture or dislocation of the wrist
- Chronic pathologies: diabetes, rheumatoid arthritis, renal failure, hypothyroidism
- obesity
- Water retention from menopause or pregnancy
The diagnosis is most often made clinically, and electrodiagnostic tests help the surgeon in assessing the severity of the compression and estimating the recovery time.
Non-surgical treatment:
- Immobilization with a splint in a neutral position, to reduce the pressure inside the carpal canal (30 degree wrist extension and wearing the splint only at night);
- Exercises as instructed by a doctor during physical therapy. Only mild or moderate cases.
- Anti-inflammatory medication
- Corticosteroid injections, in selected cases. It is not routine because of the risks associated with injecting this product.
The surgical treatment is performed with regional block with / without sedation.
Decompression of the carpal canal can be done by incision in the wrist or endoscopically.
The surgery consists of an incision at the level of the wrist and extended to the palm, to section the transverse carpal ligament (its roles: it prevents the tendons in the canal from being pushed up, increases flexion by 2%, holds the carpal bones together). Its sectioning does not pose problems, and the changes made by this sectioning cannot be considered complications. The benefits of nerve release are well balanced, far superior to any changes produced by the sectioning of this ligament.
During the intervention, the flexor tendons and floor of the carpal canal are inspected to exclude other causes.
If the use of the cauter is contraindicated, a drainage tube will be fitted; alternatively, the incision will be closed.
Postoperative steps
You will have a bulky bandage to prevent wrist movements (if necessary a cast will be used), which can cause pain and postoperative bleeding. This dressing is kept for 2 days.
The dressing will be removed 48 hours postoperatively for incision inspection.
Movement of the hand will start early, after the inflammatory phase (day 0-4) passes and you will be able to tolerate the movements. The wires are removed after 14 days, followed by the application of silicone gels. The painful discomfort will be managed with the prescribed drugs.
You will wear a splint in a neutral position during the night for 3 weeks, for your comfort.
Sensory recovery should occur within the first 2 weeks postoperatively for mild and moderate forms; whereas for the severe ones sensory recovery happens only after 1 year. One month after surgery, patients can lift a maximum of 1 kg in one hand, and at 6-8 weeks there are no weight restrictions.
Without surgery, the progression follows these phases:
- Aggravation: hypoesthesia until anesthesia in the region of the medial nerve, atrophy of the tender eminence with the decrease of the clamping mechanism (forceps).
- Anesthesia leads to failure to feel burns or stings and which lead to complications such as soft tissue infections, osteoporosis, arthritis and then amputation of the fingers.
