Anatomy of tail bone (coccyx)
Table Of Content:
The tail bone is medically termed as coccyx. It is the last bone in the spinal column. The upper part is made of cervical, thoracic, lumbar and sacral vertebrae. The coccyx is situated below the sacrum. The anatomical location of coccyx coincides with the crease of the buttocks. Internally, the tip of the tail bone is located 2.5 cms above the anus with a slight forward bend.
Pain arising in the area of the tailbone is called as tailbone pain. The pain can be due to problems in the coccyx itself or the surrounding bones, muscles and ligaments. The diagnostic feature of tailbone pain is the localized tenderness of the tailbone when it is palpated from outside. The pain in the coccyx is medically termed as coccydynia, coccyalgia or coccygodynia.
Tailbone pain happens commonly after sitting for a very long time or rising from a sitting posture. The people who suffer from this kind of pain describe it as the pain coming on from sitting on marble or a very hard substance. The commonest causes of tailbone pain are stress of pregnancy, injuries to the back and falls. Other trigger factors for the pain are sleeping on the back, standing for a very long time, jumping, running, carrying heavy weights, after sexual intercourse. Simple activities like straining for a bowel movement, coughing or sneezing can aggravate this type of pain. The pain is usually better by bending forward.
Risk factors for coccyx pain
- Sedentary work pattern that involves sitting for long hours.
- Female sex
- Weight loss that is sudden or associated with an illness
- Sports that entail frequent falls like football, skating, wrestling, snowboarding, skiing etc
- Sitting posture sports like boat rowing, cycling, horse riding and car racing.
- Anatomical deformity where the tailbone protrudes out like a lump just above the anal region.
Causes of coccyx pain
Acute tailbone pain:
Acute tailbone pain is usually sudden in onset. The causes of acute pain are:
(a)Injury or Trauma Related Acute Pain:
Direct fall, childbirth especially if forceps delivery is done, car accident etc can cause injury to the spinal column and lead to pain. The diagnosis of such a pain can be done by physical examination and palpation. An x-ray is usually not needed to diagnose coccyx pain unless a fracture is suspected. The various types of injury or trauma that can occur are:
- Sitting: Sitting for long hours due to work requirements especially if the chair or surface is hard, can cause a dull pain in the coccyx region. The pain is not very disturbing and will go away with change in position or walking around.
- Bruise: Contusion or bruise caused by a blunt injury can lead to a dull aching pain. The symptoms are pain that increases on sitting. To get relief one could try cold compress and ice packs. Pain relieving medicines like analgesics may be indicated. A bluish bruise may be seen on the skin in the lowest part of the back which will get relieved in a few weeks. If it a bone bruise then it will take a few months to recover. Using a U shaped pillow for sitting will help to reduce the pain.
The only way to differentiate the cause of the bruise being skin or bony in origin is an X-ray or MRI.
- Sprain: Sprain in the tailbone area means a rupture or over stretching in the muscles or ligaments arising from the coccyx and connecting other bones in the pelvis. The commonest symptom is pain the lower back that increases on sitting. There is also tenderness on palpation of the coccyx region. The treatment modalities include steroid or anesthetic injections. Prolotherapy or sclerosant solution insertion may also be used in treating cases of severe pain.
- Fracture: Fracture in the tailbone needs to be diagnosed with the help of an X-ray. The symptoms are ac cracking or popping sound. Pain is sudden in onset and very sharp in nature. There is a numbness and bruised feeling in the area of the tailbone. The patient is unable to sit comfortably. Treatment is mainly done by analgesics. Using a U shaped pillow or tailbone guards will help to relieve the pain. In very few cases, surgical removal of the coccyx may be required. The time taken for the fracture to heal is anywhere between few months to one year. The patient may feel numbness of the affected region when sitting.
- Subluxation: When the bone moves from its anatomical location, it is called luxation or subluxation. When the slipping of the coccyx vertebrae is greater than 25%, it can present with symptoms similar to fracture of tailbone. Luxation means that the tailbone is displaced from both ends and subluxation indicates that the displacement is only from one end.
- Hairline fracture: A small crack that takes place in the bone is called a hairline fracture. It is seen commonly in women atheletes and females that have weak bones (osteoporosis). These minor fracture are detected with the help of CT scan or MRI.
(b) Non traumatic Acute Pain
- Anal abscess is an infection with localized pus collection. It can happen in Crohns disease or ulcerative colitis (inflammatory bowel disorders). Other causes are cancer of the rectum. The symptoms are pain that is throbbing in nature with or without a swelling or lump. At times there is an abnormal opening with discharge called a fistula. A discharging fistula can give rise to pain in the coccyx region.
- Shingles is a viral skin infection caused by Herpes Zoster. It is diagnosed by presence of an itchy rash with crust formation on either sides of the coccyx.
- Infection of the coccyx is called osteomyelitis
- . The symptoms are pain over the coccyx which may be dull or sharp in nature. There will be redness and swelling on the tailbone region.
- Medical procedures can also cause tailbone pain. Some of these procedures are epidural anesthesia, colonoscopy, cystoscopy, spinal tapping, IUD insertion, surgery of the spine, hysterectomy or other pelvic surgeries.
Chronic tailbone pain
Pain that lasts for more than three months is categorized as chronic tailbone pain. It can occur due to tailbone hypo or hypermobility. The causes are:
(a) Idiopathic pain: If there is no known cause of the tailbone pain it is labeled as idiopathic. The possible causes are structural deformity of the spine called as scoliosis or an abnormal mobility of the coccyx which could be because of abnormal fussion between the sacral and coccyx vertebrae.
(b)Injury: Injury can lead to abnormal mobility of the tailbone. This increased mobility can lead to pain. Chronic pain is mainly due to prolonged inflammation and subsequent degeneration of the small joints in the lower vertebral column.
(c) Levator Ani Syndrome: Pain in the coccyx or coccydynia can occur due to prolonged sitting on a soft surface like a sofa or a car seat. The symptoms are pain and tenderness in the tailbone area, vulva, buttocks and perineum. It can be prevented by using a wedge pillow while sitting. If long sitting is anticipated, take breaks and walk around to prevent the muscles from becoming stiff.
(d) Myofascial pain: This type of pain is mainly a result of repeated stress or injury to the lower back. The common causes are cycling, horse riding, sit ups, driving etc. The symptoms are pain and tightness in the muscles of the lower back. Treatment involves massage techniques that are called myofascial release. The manipulation of the affected muscles, injection of local anesthetics in the muscle knots are some methods used for pain relief.
(e)Ankylosing spondylitis: This is a form of spinal arthritis wherein there is an abnormal fusion of the vertebrae. This leads to long standing back pain with sever stiffness. The pain aggravates by bending forward and gets better by moving around.
(f) Calcium deposits in the tendons surrounding the joints.
(g) Pilonidal cyst
(i) Mal alignment of the coccyx
Tailbone pain in pregnancy
Tailbone pain is very common during pregnancy because the muscles and ligaments of the pelvic floor are under constant stress of the growing uterus. The hormone relaxin makes the pelvic floor muscles relaxed and causes increase in the movement of the tailbone. In the last few weeks of pregnancy, the pain gets worse. Another reason is pubic symphysis dysfunction where the gap between the bones in the pubis increases and leads to pain in the lower back, sacrum and inner thighs. The treatment is mainly analgesics, physiotherapy and epidural anesthesia.
Tailbone pain during pregnancy can be prevented by using a donut or wedge shaped pillow. Kegels exercises are very effective in improving the strength of the pelvic floor muscles and muscles around the urethra. They also reduce the mobility of the coccyx and tailbone pain.a support belt can be used if advised by the doctor.
Psychological tailbone pain
The major causes of tailbone pain are physical in nature and those related to injury. However there can be some psychological reasons for pain in the tailbone area like:
- Coccyx pain that is not increased or relieved by sitting, walking or other postural changes. This pain is related to symptoms like depression and mood changes.
- Anorectal neuralgia is a pain occurring in the anal region which is commonly seen associated along with neurosis.
Referred pain in tailbone
Referred pain means that the pain is felt in the tailbone but the origin of the pain is somewhere else. If the pain is referred pain then there will be no local tenderness of the coccyx bone. The causes of referred tailbone pain are:
- Benign tumour growths that occur near the coccyx like epidermal cyst, lipoma, dermoid cyst, haemangioma etc can be seen like a small lump in the lower back. They can cause tailbone pain which is mostly chronic.
- Hemorrhoids or piles are the swellings in the veins of the rectum that occur due to chronic constipation or during pregnancy. The symptoms are burning, fullness in the rectum, painless bleeding from anus, itching around the anal opening and low back pain.
- Tarlov cyst
- Reflex sympathetic dystrophy
Some other causes of low back pain
There are some cases where the pain arises in the lower part of the back but the cause of the pain is not the coccyx. The diagnostic feature of tailbone pain is that is gets reduced after giving injections directly into the bone. Other causes of low back pain or stiffness of the back are:
- Spondylosis: Spondylosis is a degenerative disease of the lumbar disc. There is herniation or abnormal protrusion of the lumbar vertebrae. This is commonly seen in the L4-L5 or L5-S1 segments. The pain is felt in the lower back and it radiates to the thighs and legs. This kind of pain is called as sciatica. It is associated with tingling and numbness of the extremities. The pain is usually aggravated by long continued rest like sitting and is better when the patient begins to walk around. The pain is felt in the coccyx region but it radiates to the legs and so it can be diagnosed and differentiated from tailbone pain.
- Fibromyalgia: Fibromyalgia is a disorder of the muscles where the tenderness is symmetrical and can be felt on both the sides just above the buttocks. There is no local pain or tenderness over the coccyx. Pain in shoulders and muscles of the upper back is also common. The patients who suffer from fibromyalgia have a psychosomatic etiology in the background.
- Proctalgia fugax: This is another condition where there is a sharp pain that is sudden and violent in onset. It last only for a few seconds and is felt mainly over the anal region. It happens more ar night and has no relation to any disease of the rectum or the bowel.
- Piriformis syndrome: This disorder occurs due to a fall directly on the back. The piriformis muscle that goes from the sacrum to femur is affected; it gets swollen and inflamed causing pain and discomfort. The pain originates in the buttock and tailbone region. In females the pain is felt in the labia and in the scrotum in males. The aggravating factors of the pain are running, sitting, squatting and during bowel movements.
- Pudendal Neuralgia: This is basically a damage to the nerve in the pelvic floor. The pudendal nerve can be affected in diabetes or as a result of pelvic floor injury. The symptoms are sharp stabbing type of pain with numbness and tingling that is felt around the genital regions, anus and the coccyx. The pain increases by sitting and is better by using a cushioned seat or wedge pillow.
- Pelvic Floor Dysfunction: This is an increase in the tension within the muscles that are located between the coccyx and the genitalia. The main causes are forceful holding of the urine and stool, abnormalities of the posture, sexual abuse, labour and childbirth injuries, IBS, endometriosis etc. The symptoms are frequency of urination, constipation, pain during sexual intercourse and low back pain. The best way to strengthen the pelvic floor muscles is to do squats and kegels exercises because these exercises help to make the buttock muscles strong by pulling the tailbone inwards. This helps to relieve the pain in the tailbone region (lower back pain)
Diagnosis of coccyx pain
The steps to diagnose the exact cause of the coccyx pain are as follows:
- Inspection of the tailbone area for any visible bruises or lumps
- External palpation to check for tailbone tenderness or crackling sound
- Internal palpation is done through the rectum. The examiner inserts a gloved and lubricated finger into the anal opening and checks for any internal growths or tumors. The mobility of the tailbone can also be assessed in this way.
- X-ray: The specific x-ray that is required to diagnose pathology of the tailbone is X-ray of the spine in sitting or standing position. Any abnormality of the sacral spine, problems in the spinal curvature, fractures, disc herniations, bony growths, spurs or spicules and fractures can be easily diagnosed on a digital x-ray.
- CT Scan: Computerized tomography is effective in diagnosing problems of bony origin. It can also effectively pick up hairline fractures.
- MRI: Magnetic resonance imaging is a useful imaging technique to view soft tissues and so it can diagnose tumors, dislocations, fractures, disc degeneration, inflammations, joint cavity reductions, bone growths etc.
- Stool test: If rectal cancer is suspected, the stool should be tested for presence of blood.
- Complete blood count to check for infections.
Management and prevention of coccyx pain
The treatment of tailbone pain is mainly medication along with lifestyle modifications and change in sitting habits. The following methods are effective in reducing the pain.
- Sitting Posture: For a person with tailbone pain, it is important to sit by leaning forward so that the weight of the upper body does not go onto the lower part of the spine. Another thing that can be tried is sitting on one check of the buttock at a time and alternating sides. If one has to sit for long hours, then getting up and moving around after every half an hour can also help to reduce the pain.
- Sitting Cushions: Using a U shaped pillow or cushion on the seat can reduce the pressure of the hard surface of the coccyx and reduce the pain. A complete ring pillow or a wedge shaped pillow can be used depending on what is convenient to you. There are also specialized chairs that have a padding on the lower part so that the pressure on the tailbone can be reduced. If none of the above options are available you can simply use another chair to put your legs up while you sit and relieve your lower back. Sitting on very soft sofas or chairs can actually increase the coccyx pain rather that relieve it.
- Bowel Movements: Patients with tailbone pain should maintain their diet to avoid constipation. Straining at a bowel movement due to a large hard stool can increase the pain in the tailbone further.
- Exercises: People with chronic tailbone pain will benefit by exercises like walking, squats, swimming especially on the back, stretching exercises and groin stretch. However if you have an injury on the coccyx bone then you should avoid any kind of strenuous movement or exercise. Always take the advise of your doctor before beginning any kind of exercise.
- Local fomentation: Application of ice packs in the form of ice cubes wrapped in a napkin, hot water bag and sitz bath are some thermal modalities that provide symptomatic relief. Use each of them for atleast 20 minutes each for two to three times a day.
- Medicines: NSAIDs or non steroidal anti inflammatory drugs like ibuprofen are commonly used to control tailbone pain. Acetaminophen can also help to reduce the swelling. If there is a nerve involvement, then gabapentin or pregabalin may be used. Diabetic neuropathy and herpes infections commonly affect the nerves. In cases of severe pain, opium derivatives like fentanyl citrate and oxycodone may be prescribed. Local application of analgesic creams will be effective in the cases where the pain is due to a muscle sprain or over stretching.
- Physiotherapy: Structured exercises and muscle stimulation can help to relieve tailbone pain. The various types of procedures that may be carried out are:
- Massage: a gentle massage will help to relieve the muscle soreness and pain
- Manipulation of the Coccyx: This is an OPD procedure where the doctor will use a local anesthetic agent and numb the coccyx region. Thereafter the manipulation, mobilization or alignment of the coccyx can be done. This procedure is performed by inserting a finger with glove and lubricant applied on it in the rectum. The other hand is kept on the tailbone from the outside to support it. Then using both the hands, the coccyx is flexed and extended repeatedly till one minute. This maneuver is most effective in those individuals who have tailbone pain that has come up after some kind of trauma or in people with a fused and immobile coccyx. The manipulation of the coccyx along with local anesthetic drug is effective in reducing the pain.
- Acupuncture: Acupuncture is a method of treatment where certain points in the body are identified and stimulating those points with the help of needles, helps to relieve the pain. There are no studies that show the efficacy of this method.
- Kinesio Tape: There are no definite studies that show the efficacy of this method of treatment for tailbone pain.
- Injections: There are four types of injection procedures that can be used to relieve tailbone pain.
- Ganglion Blocks: This method is effective in providing long term relief. A local anesthetic agent like lidocaine is injected into the coccyx. This is very effective in providing relief from the pain in those cases where the cause of the pain is ganglion over activity. The relief is felt within minutes of the injection and it lasts for a few months. If a longer pain relief is intended, then the injection of local anesthetic agent can be combined with botulinum toxin.
- Ganglion ablation: If the tailbone is chronic and long lasting, then for long term relief, the ganglion impair is destroyed by ablation. Nerve ablation that is done by means of phenol, injections of ethanol or ablation with radiofrequency provide much longer relief to the patient as compared to injections. The procedure of ablation may need to be repeated after a few years or so if the need arises.
- Prolotherapy: This method is used mainly for treating ligaments that are injured or torn post injury. A sclerosant solution is injected in the joint space just next to the coccyx. This agent leads to the proliferation and growth of the ligament and thus heals the tear and helps it grow.
- Steroid injections: Steroid injections can be given alone or combined with an anesthetic agent. The injection is given in the joint space between the sacrum and the coccyx. It is most effective in treating tailbone pain that arises out of bursitis (inflammation of the bursa in the sacrococcygeal joint)
- Nerve Stimulation Therapy: There is a procedure that involves the stimulation of the spinal cord nerve roots by a device similar to a pacemaker. The device is implanted beneath the skin in the area near the hip. The sacral neuromodulation process helps to relive tailbone pain especially after fracture of the coccyx.
- Surgery: Surgical removal of the coccyx is called as coccygectomy. The surgery could be for removal of a few parts of the coccyx that are hypermobile or the entire coccyx. The indications for surgical removal of the coccyx are-
- Long standing and chronic coccyx pain.
- Cancer of coccyx
- Bony growths in the coccyx
- Permanent displacement of the coccyx
- Subluxation or dislocation of the coccyx following a trauma or accident.
In most of the above cases, surgery is successful in removing the pain symptoms for a long time period. The recovery from the surgery may take a few months to one year.
Surgery for tailbone pain is not effective if there is absence of local tenderness or tailbone hyper mobility. If the patient has pain in the lower back or if the pain extends downwards to the hips and the legs, then removal of the coccyx will not provide pain relief. The complete removal of the tailbone has less complication as compared to partial removal. Some known complications of tailbone surgery are:
- Wound gapping
- Pain that remains even after the surgery
- Incontinence of the bowel
- Infection of the surgical wound
- Weakness of the muscles of the pelvic floor.