Steroid injection in carpal tunnel syndrome

Commonly used for treatment and as a diagnostic tool in CTS.

• used for patients with mild to moderate disease, specially for pain
• a randomised control trial compared three groups (37 patients in each group)which received 80 mg methylprednisolone steroid injection, 40 mg methylprednisolone steroid injection, and placebo
  • improved symptom scores at 10 weeks were observed with steroid injection while there was no difference in the placebo group at one year
  • overall, surgery was carried out in 75% of the patients
• worse results after steroid injection are reported in patients with more clinically severe disease, diabetes, older people, and where symptoms are permanent or unremitting (1)

Procedure:

• explain the procedure and get consent from patient
• make certain that there are no contraindications to a local steroid injection
• localise injection site
  • actively flex wrist with the thumb and little finger opposed to localise the palmaris longus tendon
  • plan to inject at level of distal wrist crease medial (on ulnar side) of palmaris tendon n.b. inject in the same position in the 15% of patients with no palmaris tendon
  • alternatively injection site can be lateral to the palmaris longus tendon
• sterilise the skin with alcohol or iodine
• use 10mg(0.25ml of 40mg/ml)Depomedrone
• get patient to rest affected hand extended on the table
• injection
  • avoid any veins
  • use orange needle which is inserted to the hilt at 60 degrees
  • check that cannot withdraw blood before injection and that the median nerve hasn't been inadvertently touched when the patient would experience pain and paraesthesia
    • if the nerve is hit, withdraw slightly and move the needle slightly radially/medially The injection should require minimal pressure on the syringe
• withdraw needle and apply pressure for two minutes
• warn the patient that if they develop severe pain and their symptoms become acutely worse they must inform the doctor as an emergency as they may have developed an acute haematoma
• provide patient with leaflet regarding the carpal tunnel steroid injection (2,3,4).

There is no good evidence to support repeat steroid injection in patients who relapse after carpal tunnel injection (1)

Reference:

• (1) Middleton SD, Anakwe RE Carpal tunnel syndrome. BMJ. 2014;349:g6437
• (2) Wadsworth T.C. Injecting soft tissue lesions of the hand and wrist. Practitioner 1996; 240: 482
• (3) Burton C, Chesterton LS, Davenport G. Diagnosing and managing carpal tunnel syndrome in primary care. Br J Gen Pract. 2014;64(622):262-3.
• (4) LeBlanc KE, Cestia W .Carpal tunnel syndrome. Am Fam Physician. 2011;83(8):952-8.