Posterior tibial nerve blocks for the treatment of coccydynia pain: A Prospective cohort study

Coccydynia is a pain felt in the tailbone (coccyx), which is the last bone at the bottom of spine, It was originally attributed to the injury of the coccyx with inflammation of surrounding tissue by Simpson (1). The main clinical features are pain and tenderness in the area just above the buttocks, the pain may be dull and achy most of the time, with occasional sharp pains, it will be worse when sitting down, moving from sitting to standing, standing for long periods, during sex and defecation.

It is often for the patient to have difficulty in sleeping and carryout everyday activities such as driving or bending over. Some people also have back pain, shooting leg pains (sciatica) and painful buttocks and hips.

Common causes of coccydynia include; childbirth, an injury or accident such as fall, an injury or accident such as a fall, repeated or prolonged strain on the coccyx, poor posture, being overweight or underweight.  Less common causes can include a bony growth on the coccyx, the coccyx being too flexible or too rigid and arthritis. Rare but serious causes include infection and cancer.

Current guidelines strongly recommend conservative treatment and discourage surgical option due to the risk of long-term complications (2). Non-surgical options for the treatment of coccydynia include non-steroidal anti-inflammatory and analgesic medications, rest, hot baths, massage, and a ring-shaped cushion to protect the coccyx from repetitive trauma. Physical therapy modalities include shortwave diathermy to relieve pain and muscle spasms by deep tissue heating, interferential current to provide temporary relief.

 Ganglion impar block with local anaesthetic and steroids may be indicated if the conservative treatment fails. The Ganglion impar block is routinely performed in operation theatre set up in prone position with the help of fluoroscopy or ultrasound guidance.

 We hypothesize that our spinal nerves are pseudo unipolar and carry the information in bi-directional, therefore, blocking the peripheral nerves should block the pain due to coccidynia (3), the case report by Hammodi has shown prolonged relief of coccidynia pain with peripheral nerve (posterior tibial) injections (4).

The present study will examine the efficacy of peripheral nerve block (posterior tibial nerve) in treatment of coccidynia in patients attending our pain clinic.