Coccygeal area pain has numerous causes. Many of these causes involve disorders of anatomic structures near the coccyx rather than the coccyx itself.
The exact incidence of coccygeal area pain is unknown, but it is far less common than low back pain.
Etiology of Coccygeal Area Pain
Coccygeal area pain may originate from disorders of
The coccyx itself
Nearby anatomic structures
Coccygeal disorders that cause coccydynia (coccyx pain) are most commonly
Traumatic or non-traumatic musculoskeletal disorders: Hypermobility, bone spurs, dislocations, fractures and other injuries, and osteoarthritis
Coccygeal cancers are rarer causes of coccygeal pain. The cancers can be primary (ie, originating in the coccyx) or secondary. Primary coccygeal cancers include chordoma, which is often fatal. Secondary coccygeal cancers may result from direct invasion from adjacent structures (eg, from rectal cancer) or be metastatic from malignancies elsewhere in the body.
Disorders of nearby anatomic structures that cause coccygeal area pain include
Anal fissures
Crohn disease
Hemorrhoids
Ischial bursitis
Levator syndrome (spasm of the levator ani muscle)
Perianal or perirectal abscess
Perineural cysts of the sacrum (Tarlov cysts)
Pilonidal cysts
Piriformis muscle pain
Pudendal nerve pain
Retrorectal tumors (ie, tumors located in the space posterior to the rectum and anterior to the sacrum/coccyx, such as retrorectal hamartoma)
Sacroiliac joint pain
Colorectal cancers rarely manifest with coccygeal area pain unless they have invaded nearby bony structures.
Pathophysiology of Coccygeal Area Pain
The coccyx is comprised of 3 to 5 coccygeal vertebral bodies, at the most inferior end of the spine. The coccyx is located at the midline, just below the sacrum, posterior to the rectum, and 2 finger breadths superior/posterior to the anus.
Pain caused by a disorder at one anatomic site may be referred to adjacent regions. Further, symptoms from one region may cause or exacerbate symptoms in another region. For example, coccyx pain may cause reactive muscle spasm/guarding throughout the pelvic floor muscles, resulting in pelvic floor myofascial pain. Conversely, pain, spasm, and tightness within the pelvic floor muscles that attach to the coccyx may cause coccygeal pain.
A common complication of untreated coccydynia is that patients may develop a chronic pain syndrome.
Evaluation of Coccygeal Area Pain
Evaluation of coccygeal area pain is challenging because its causes may involve one of several organ systems that are typically treated by different medical specialists (eg, orthopedists, gastroenterologists, gynecologists). Referral to the wrong specialist may delay diagnosis.
History
History of present illness should identify the onset (including whether traumatic or non-traumatic) and duration of pain and whether the symptoms have changed over time. The specific location of the symptoms should be determined as accurately as possible. Because many patients have poor body awareness of their coccygeal region and have difficulty identifying the specific site of their pain, it may help to ask the patient to point with a single finger to the specific site of the worst pain.
Ask the patient about exacerbating or alleviating factors, particularly sitting, movement, and defecation.
Other symptoms to note include warmth, swelling, and pus/discharge at the area.
Patients are asked whether they have noted blood in the toilet bowl or on toilet paper after wiping. Obtaining a sexual history to inquire about recent anoreceptive activities may also be relevant.
Neurologic symptoms in the perineum or lower extremities should be sought, including numbness, weakness, paresthesias, and difficulty controlling bladder or bowels.
Review of systems can help the clinician assess which organ systems are most likely to be involved. Particular attention should be paid to symptoms related to the skin, musculoskeletal system, colorectal, and gynecological systems.
Past medical history focuses on whether there is any history of prior pelvic musculoskeletal pain conditions, pilonidal cysts, anorectal disorders, sexually transmitted infections, or malignancies (especially any pelvic malignancies).
Physical examination
Physical examination of the coccygeal region starts with inspection and light palpation of the skin for any lumps/masses, redness, warmth, fistula tracks, or discharge.
Careful, systematic, deeper palpation is done to identify the specific area of tenderness and distinguish pain from the coccyx itself, versus pain from nearby structures. Thus, palpation includes areas over the paracoccygeal muscles, piriformis muscles, lumbosacral facet joints, sacroiliac joints, ischial tuberosities, and anal region. Additional provocative maneuvers can be done for many of these sites, depending on clinical suspicion.
In cases where coccygeal palpation does not reveal tenderness that reproduces the patient's symptoms, further internal physical examination may be appropriate. For example, digital rectal examination should be done to detect thrombosed or bleeding hemorrhoids, tenderness with or without a mass, and the presence of blood. Rectal tone should be noted. The coccyx itself may be palpated during rectal examination.
Neurologic examination of the perineum (particularly sensation and anal wink reflex) and lower extremities (including motor, sensory, and reflex function) is done.
Red flags
The following findings are of particular concern:
Neurologic symptoms or signs
Constitutional symptoms, such as unexplained weight loss, fatigue, fever, and lymphadenopathy
Constant, chronic, atraumatic pain
Purulent drainage
Rectal mass
Rectal bleeding or pain with defecation
Interpretation of findings
Direct, external, focal palpation of the coccyx is often the most important and revealing part of the physical examination. In the vast majority of patients with a coccyx disorder, this palpation will reproduce the pain that they have been experiencing while sitting. If external coccyx palpation fails to reproduce such tenderness, then internal examination and searching for alternative explanations for the patient's pain become all the more important.
Pain and tenderness from a coccyx disorder is typically located in the midline, 2 finger breadths posterior/superior to the anus. Pain lateralized to one side or the other suggests a non-coccygeal disorder. Pain that is worse while sitting suggests a coccyx disorder (if the pain is at the midline) or ischial bursitis (if the pain is at the right or left lower buttock). Coccygeal pain is especially worse while sitting leaning partway backward. Pain that initially worsens during the transition from sitting to standing suggests probable coccygeal hypermobility. Pain that is worse during defecation suggests anal fissure or proctitis, although this symptom is sometimes due to coccyx pathology.
A tender external swelling suggests a perianal abscess or pilonidal cyst. Tender swelling on rectal examination suggests a perirectal abscess. Nontender swelling or mass on rectal examination suggests a tumor.
Purulent drainage suggests a pilonidal cyst, perianal abscess, or fistula (eg, from Crohn disease).
Blood only on the toilet paper after bowel movements is typical of hemorrhoids. Blood in the toilet bowl may result from hemorrhoids or from gastrointestinal bleeding from other anorectal disorders, such as ulcerative colitis or colorectal cancer. Blood mixed in the stool suggests a bleeding source above the anus.
Patients with focal coccyx disorders typically have no neurologic deficits on physical examination. Thus, the presence of neurologic symptoms or physical examination findings suggest non-coccygeal sources, such as cauda equina syndrome, lumbosacral radiculopathy, or sciatic nerve irritation at the piriformis muscle.
Testing
Testing is done depending on what diagnoses are suspected.
If findings are localized to the coccyx, then imaging studies are not required, particularly for acute pain of less than 2 weeks duration following minor trauma. However, if symptoms persist beyond 2 weeks, or if there is more substantial trauma, then radiographs should be done. Lateral views with collimation (to cone-down to the area of interest, decreasing patient radiation exposure and improving image quality) are preferred in both the sitting and standing positions, to assess for excessive/abnormal movement (dynamic instability) while sitting (1).
Patients with persistent symptoms who have no obvious cause on history and physical examination may benefit from pelvic magnetic resonance imaging (MRI), which can assess both bones and soft tissues, thus screening for malignancies and masses. Computerized tomography (CT) scanning is an alternative, but MRI gives better definition of soft tissue structures and does not expose the patient to ionizing radiation.
Anorectal masses, ulcers, and/or bleeding can be assessed by colonoscopy, sigmoidoscopy, or proctoscopy.
Blood tests are generally not helpful unless there is suspicion of underlying infection, in which case testing could include a complete blood count, erythrocyte sedimentation rate, C-reactive protein, and diagnostic tests for sexually transmitted infections. A urinalysis is typically not needed for posterior pelvic pain, but is helpful for symptoms in the anterior (bladder) region.
Evaluation reference
1. Maigne JY, Guedj S, Straus C: Idiopathic coccygodynia. Lateral roentgenograms in the sitting position and coccygeal discography. Spine (Phila Pa 1976) 19(8):930-934, 1994. doi:10.1097/00007632-199404150-00011
Treatment of Coccygeal Area Pain
Treatment of cause
Treatment is directed at the causative disorder (1).
Treatment of coccyx disorders often begins with oral analgesics and use of cushions to relieve coccygeal pressure during sitting. Further treatment may include injections of local anesthetics and corticosteroids, and in rare instances surgical amputation of the coccyx (coccygectomy).
Pelvic musculoskeletal pain syndromes (such as sacroiliac joint pain, piriformis myofascial pain, pelvic floor pain, ischial bursitis) often respond well to a combination of physical therapy and injections of local anesthetics and corticosteroids.
Subspecialty consultation and treatment may be necessary with a colorectal surgeon, gastroenterologist, or gynecologist, depending on the organ system involved. Timely diagnostic work-up and treatment are warranted to avoid the complication of a chronic pain syndrome.
Treatment reference
1. Foye PM. Coccydynia: Tailbone Pain. Phys Med Rehabil Clin N Am 28(3):539-549, 2017. doi:10.1016/j.pmr.2017.03.006
Key Points
Patients often have difficulty localizing coccygeal area pain, so it can be caused by disorders of many different organ systems.
Symptoms and signs of coccygeal disorders are typically in the midline.
Lateralized manifestations are more likely to represent extra-coccygeal disorders, and testing should be guided by specific findings.
Evaluation and treatment may require collaboration among specialists in musculoskeletal medicine, pain management, colorectal disorders, and pelvic floor physical therapy.
A common complication of coccygeal area pain is a chronic pain syndrome, which may be avoided by timely evaluation and treatment.
