Coccyx Pain – Causes, Symptoms, Diagnosis, Treatment

Coccyx Pain means the disabling pain in the coccyx that is usually provoked by sitting or changing from a sitting to a standing position. This tail bone pain may radiate rostrally to the sacrum or lumbar spine or laterally to the buttocks. Patients may rarely present with associated rectal pain and radiating pain or radicular symptoms.  One-third of patients have associated back pain, contributing to misdiagnosis with misguiding [rx,rx,rx,rx]. According to the compounding the problem, most neurosurgeons and spine specialists, and orthopedic spine surgeons are uncomfortable treating coccygodynia due to a lack of surgical training with coccygectomy.

Anatomy

The coccyx is the terminal region of the spinal column. Although the singular term “tailbone” implies that this is a single bone, it actually consists of 3 to 5 separate vertebral bodies, with substantial variability regarding whether they are fused together or not. The coccyx articulates with the sacrum through a sacrococcygeal joint (including a fibrocartilaginous intervertebral disc and bilateral zygapophysial [facet] joints). The sacrococcygeal and intra-coccygeal joints allow for a modest amount of coccygeal movement, which is typically forward flexion while weight-bearing (sitting).[rx] The coccyx is a Greek word that means the beak of a cuckoo bird as the side view of the tailbone resembles the side view of a cuckoo bird’s beak.[rx]

On the anterior surface of the coccyx, the following muscles gain attachment – levator ani, iliococcygeus, coccygeus, and pubococcygeus. On the posterior coccygeal surface, the gluteus maximus is attached. Also attached to the coccyx are the anterior and posterior sacrococcygeal ligaments, which are a continuation of the anterior and posterior longitudinal ligaments. Bilateral attachments to the coccyx include the sacrotuberous and sacrospinous ligaments.[rx] Besides being an insertion site for these muscles and ligaments, the coccyx is also attached to the anococcygeal raphe (which extends from the anus to the distal coccyx, holding the anus in its position within the pelvic floor).

[stextbox id=’grey’]Functionally, a tripod is formed by the bilateral ischial tuberosities (at the right and left inferior buttock) and the coccyx (in the midline). This tripod supports weight-bearing in the seated position.[rx] Nerves of the coccyx include somatic nerve fibers as well as the ganglion impar, which is the terminal end of the paravertebral chain of the sympathetic nervous system.[rx] The plural of the coccyx is coccyges or coccyxes.[/stextbox]

Causes of Coccyx Pain

There are many causes of coccyx pain or coccygeal pain that are

• Ranging from musculoskeletal injuries (such as contusions, fractures, dislocations, and ligamentous instability) to infections (osteomyelitis) and may have fatal malignancies (such as chordoma).[rx]
• The causes also include direct vertical trauma, repetitive microtrauma, and childbirth are common causes of coccyx pain.
• More serious underlying causes must be excluded, such as infections (including both soft tissue abscess and osteomyelitis) or malignancy (including chordoma, which has a high fatality rate).[rx]
• Coccyx pain or coccydynia can be a referred pain due to as lower gastrointestinal or urogenital disorders.[rx]
• Neurological causes that lumbar disc prolapse has been reported as a possible etiology in a limited number of cases.
• The outcome of direct vertical trauma to the coccyx can vary from contusion to fracture-dislocation of the coccyx.
• Traumatic or non-traumatic compromised of the coccygeal ligaments can result in coccygeal dynamic instability (excessive movement of the coccyx during weight-bearing, while sitting). The abnormal mobility of the coccyx can result in coccygeal pain.
• Abnormally mobile coccyges can be either hypermobile (due to lax ligaments injury) or hypermobile (rigid). The coccyx may be subluxated or dislocated anteriorly or posteriorly, unstable, or even dislocated.[rx]
• Coccyxes of certain abnormal shapes are more leading to coccydynia than others.[rx] Abnormal coccygeal morphology or position also predisposing to coccyx pain include abnormal lumber curvature deformity (lateral deviation) or a coccyx that is excessively flexed or bend and excessively extended.[rx]
• A distal coccyx bone spur (spicule) or small particle from broken may cause pain when the skin is pinched beneath the spur during sitting.[rx]
• Idiopathic coccydynia is a ‘diagnosis of exclusion’ after careful screening for identifiable causes.

Symptoms of Coccyx Pain

The pain symptoms may be triggers by particularly acute when an external force acts directly on the tailbone; this typically occurs during every-day activities such as sitting. Along with the bilateral ischial tuberosities, the coccyx bears the brunt of body weight during sitting.

Diagnosis of Coccyx Pain

• The typical presentation of coccydynia – is pain localized to the coccyx. In traumatic coccydynia, there will be a preceding history of trauma followed by acute onset of pain. In idiopathic coccydynia, the pain will often have an insidious onset without any obvious or specific precipitant. In coccydynia, due to other causes, a careful and thorough history will often suggest the possible etiology.
• Aggravating pain when or not typically worse – while sitting and especially while sitting in a partly reclined (backward leaning) position.[rx] The pain is usually exacerbated by prolonged sitting and cycling.[rx] Standing up from the seated position may cause a temporary but severe increase in coccyx pain.[rx] Other exacerbating factors may include standing for a long time, sexual intercourse, and defecation.[rx]
• Physical examination – includes inspection of the overlying skin for any signs suggestive of infection or other differential diagnoses such as pilonidal sinus and hemorrhoids.
• These coccygeal movements – are measured as changes in the coccygeal angle (amount of flexion) and luxation (amount of listhesis at each of the coccygeal joints). These studies allow the classification of patients with coccydynia into groups based on coccygeal luxation and mobility (hypermobile, hypermobile, and normal mobility). The normal range of coccygeal mobility is between 5 and 20 degrees.[rx][rx] Thus, if sitting causes a change in the coccygeal angle of fewer than 5 degrees, then this is hypomobility. Conversely, if sitting changes the coccygeal angle by 20 degrees or more, then this is hypermobility.[rx]
• Foye’s finger test for coccydynia – This is comparable to “Fortin’s finger, which is published on the usefulness of having patients with sacroiliac joint pain point to their site of pain, that help to find out this from lumbar pain generators.[rx]
• External palpation – usually reveals localized swelling and tenderness focally over the coccyx.
• Per rectal examination – may be useful in some patients to evaluate position the degree of coccygeal mobility and will typically explain pain by manipulating the coccyx.[rx]
• Beyond the evaluation of the coccyx itself – it is often helpful to also assess for other sources of musculoskeletal pain by performing a physical examination of the sacroiliac joints, ischial bursae, and piriformis muscles.

Stage – AP radiographs can reveal coccyx scoliotic (lateral deviation) deformity. Lateral views are always indicated as coccyx curvature can be classified into four different types:[rx]

• Type I: coccyx is slightly curved forward.
• Type II: coccyx is pointed straight forward.
• Type III: coccyx has a sharp forward angulation.
• Type IV: coccyx shows subluxation and deformity at the sacrococcygeal or the intercoccygeal joint.

Imaging

• From the lateral radiographs – the examiner can assess the intercoccygeal angle, or angulation which is the measured angle between the first and last segment of the coccyx, It is used to assess the anterior angulation or curvature deformity of the coccyx. An increased intercoccygeal angle or it position (increased forward angulation) has been reported as a possible cause of coccydynia.[rx]
• Dynamic radiographs (sitting and standing) – It is done by seating X-rays of the coccyx as a way to see the coccyx position while the coccydynia patient was most symptomatic, which typically occurs while sitting or moving in a sitting. By comparing the coccyx position while sitting versus standing, the clinician can objectively measure the amount of change that have occurred.
• Computed tomography scan (CT) – of a normal adult coccyx shows variability in the fusion of the sacrococcygeal and intercoccygeal joints. The female coccyges are more often shorter in size, straighter, and more retroverted in nature.[rx].
• Magnetic resonance imaging (MRI) – can be used to identify or examine the anterior and posterior curvature of the coccyx, the fusion deformity of the sacrococcygeal and intercoccygeal joints, tendon cartilage ligament, Flava as well as the presence of a distal coccyx bone small particle or (spur).[rx] MRI can also assist in the screening test for local malignant and non-malignant tumors and associates’ condition.[rx]
• Coccygeal discogram – This involves injecting contrast and local anesthetic into the sacrococcygeal region in an attempt to determine the specific site of pain.[rx] It can serve as a diagnostic and therapeutic procedure.
• Nuclear medicine bone scan – This is typically only used in patients with coccydynia in whom a search for malignancy or infection (e.g., osteomyelitis) is warranted.[rx]
• Routine blood tests – These studies may help in finding rare cases, that include such as infection, malignancy, gastrointestinal or urogenital problems.

Treatment

Several nonoperative interventions are currently used for the management of coccydynia including NSAIDs, hot baths, ring-shaped cushions, intrarectal massage therapy, and manipulation (manual therapy steroid injection dextrose prolotherapy and ganglion impaire block radiofrequency that are thermocoagulation and psychotherapy treatment.

The success of conservative treatment has been reported to be 90%.[rx] The following modalities can be offered in acute and chronic cases:

Acute Coccydynia

• Oral or topical nonsteroidal anti-inflammatory drugs (NSAIDs) can be helpful in modifying the acute pain, to decrease both pain and inflammation that are causing pain.
• Cushions on the patient’s chair can make sitting more comfortable. A cushion and slipping with a wedge-shaped cut-out beneath the coccyx can may in the coccyx hovering over the empty area, thus resulting in less coccygeal weight-bearing pain and less coccygeal pain. Other cushions and slipped options include U-shaped cushions and circular (donut) cushions are very helpful for acute pain.[rx]
• Pelvic floor physical therapy also may be helpful for patients who have substantial muscular pain within the adjacent para-coccygeal muscles and it associates structure.[rx] Correct sitting posture can also be assessed and improved the pain condition.
• Modalities of cold or hot compresses may be helpful in some cases of patients. However, be cautious to avoid injury to the skin by causing skin temperatures resulting in either freezing and burning injuries.
• Fluoroscopy-guided steroid injections these anti-inflammatory injections are helpful in patients with coccydynia that has been present for less than 6 months or more.[rx]

Chronic and Refractory Coccydynia

• Manipulation under anesthesia, with or without injection of local anesthetic and corticosteroid. Manipulation may be helpful in relieving ligamentous pain or pain due to muscular spasm. Different manual treatments have been reported in the literature, including levator ani massage, levator ani stretch, and joint mobilization.[rx] The levator ani massage and stretch have been reported to yield better outcomes than the joint mobilization modality.[rx]
• Ganglion impair sympathetic nerve block with local anesthetic (even without corticosteroid) can provide some patients with complete and sustained resolution of symptoms.[rx] Some patients may require repeat injections. The addition of corticosteroids may give additional relief. There are a variety of techniques for performing ganglion impair injection.[rx][rx]
• Pelvic floor physical therapy can be helpful for coccydynia, including in patients who have persistent pain despite coccygectomy.[rx]
• Transcutaneous electrical nerve stimulation (external using 2 cutaneous probes or internal using 1 cutaneous probe and 1 intrapelvic probe) may be used.[rx]
• Spinal cord stimulation may be worth considering for some coccydynia patients.[rx]
• Psychotherapy can be helpful when non-organic etiology is suspected.[rx] However, note that the psychological profile in patients with coccydynia is similar to other groups of patients, so it is important to not assume that coccydynia is due to psychological causes.[rx][rx]
• Surgical intervention – Coccygectomy involves amputation (removal) of the coccyx. This treatment is usually reserved for the small percentage of patients who fail to get adequate relief from non-surgical care.[rx] Partial or total coccygectomy has been reported to be beneficial in cases of both traumatic and idiopathic coccydynia after all conservative measures were unsuccessful.[rx][rx][rx] Post-operative complications after coccygectomy include local infection, pelvic floor prolapse (sagging), retained coccygeal fragments, and ongoing pain despite the surgery.[rx]

References