Osteochondrosis of the coccyx (coccygodynia)

Coccygodynia is a syndrome whose main symptom is paroxysmal or constant pain in the coccyx. It was first described in 1859 by J. Simpson.

Due to the anatomical features of the pelvic organs, coccygodynia is 2-3 times more common in women; coccyx pain often occurs during pregnancy. The age of patients varies, but most often it is from 40 to 60 years. A pathogenetic relationship has been revealed between coccygodynia and pathology of not only the pelvic musculoskeletal system, but also diseases of its organs. Thus, paracoccygeal pain accounts for 0.8% of women, 1.5% in proctological patients; 0.6% in urological patients. Coccygodynia is combined with such disorders as pollakiuria, urinary incontinence, chronic and frequently recurring diseases of the bladder, genitals, rectum, visceroptosis, cystic formations of the pelvis. Reflex-spastic and muscular-tonic reactions occupy a special place in coccyx pain. Pain in the caudal part of the spine is caused by damage to both the bone-cartilaginous part itself and its muscular-fibrous surroundings with neurovascular elements.

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Causes of coccygodynia

Most researchers point to the polyetiological nature of coccygodynia:

1. There is no doubt that there is a violation of mobility in the coccygeal diarthrosis. As a result of the injury, subluxations and dislocations occur in the sacrococcygeal joint, hypermobility or its immobility, which change the biomechanics of the pelvic floor and small pelvis, causing myalgia.
2. Ischemia of the nervous system, primarily the coccygeal, presacral and hypogastric nerve plexuses, forms “intrapelvic sympathetic plexitis”, “reactive neuritis”, and tunnel neuropathies.
3. Complications after childbirth or childbirth of a large fetus in women with a narrow pelvis. In this case, the sacrococcygeal joint is easily injured with the development of degenerative-dystrophic processes in the cartilaginous disc.
4. Presence of orthopedic defects of the pelvis and lumbar region, including developmental anomalies of the sacral and pelvic regions. Post-traumatic deformations, lumbarization and sacralization phenomena, hypoplasia of the coccyx and pelvic bones, joints, anomalies of the axial skeleton or connective tissue, accompanied by various changes in regional homeostasis.
5. Pathological processes in the organs and tissue of the pelvis (urethritis, prostatitis, colliculitis, salpingoophoritis, spastic proctitis, neural cysts, etc.) lead to reflex muscle-tonic reactions or neural irritations.
6. Surgical interventions on the perineum, anorectal area, pelvic organs, as well as tactical errors often lead to the development of a massive adhesion process in the pelvis or ligamentous-fascial apparatus and painful transformation.
7. Formation of local muscle hypertonus, trigger points in the muscular system; pathobiomechanical changes in the muscle that lifts the anus, including the anal sphincter, and the gluteus maximus muscle, attached directly to the coccyx; in the pelvic muscles (coccygeal, obturator, piriformis); in the muscles attached to the branches of the pubic and ischial bones; the posterior group of the thigh and adductor muscles.

Thiele (1963) drew attention to the spasm of the pelvic muscles in coccygodynia - the levator ani, coccygeal, piriformis. After the research of R.Maigne, the muscular-tonic syndrome began to be considered decisive among the pathogenetic links of coccygodynia. The reflex nature of muscle reactions was repeatedly emphasized.

According to a number of researchers, functional and anatomical changes in the pelvis, sacrum and coccyx play a significant role in the genesis of coccygodynia, leading to disruption of their kinetics and progressive muscular-ligamentous dystonia. Under the influence of various factors (traumatic, neurodystrophic, vascular-dystrophic, metabolic), pathomorphological changes in the ligamentous apparatus are formed - the formation of fasciitis, ligamentitis or ligamentoses. The most significant for the development of the disease should be considered:

• Sacrococcygeal ligaments - four dorsal, two lateral, two ventral.
• The coccygeal-dura mater ligament, which is a continuation of the terminal thread of the dura mater of the spinal cord.
• The sacrotuberous and sacrospinous paired ligaments also attach with part of their fibers to the anterior walls of the coccyx.
• Sacroiliac ligaments, especially the ventral ones.
• The tendinous arch, which is the line of initial attachment of the muscle in the area of the descending branches of the pubic bones.
• Coccygeal-rectal, unpaired, which in the upper sections is a thin, soft, elastic fibrous cord, and in the lower sections is a dense anococcygeal tendon intertwined with the muscle that lifts the anus.
• In women - the ligaments of the uterus, primarily the sacrouterine ligaments, reaching the coccyx in the lower sections, the broad ligaments of the uterus, the pubo-uterine ligaments, the round ligaments of the uterus, forming a hanging dynamic framework of this organ and other formations of the small pelvis. Of certain importance is the fibrous-elastic apparatus of the recto-uterine and utero-vesical spaces.
• In men - the fibro-ligamentous apparatus of the rectovesical and, below, rectoprostatic spaces, formed by the pelvic function plate.
• The pubovesical ligaments, together with the muscles, form the vault of the urogenital diaphragm.

It is possible that the iliofemoral, pubofemoral and ischiofemoral ligaments may have an indirect role in the genesis of coccygodynia.

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Anatomy of the coccyx

The coccyx is an unpaired bone, the lower part of the spinal column. The coccyx has the appearance of a flat, arcuately curved backwards and uneven on the sides wedge. The length of the coccyx is twice its width. The coccyx consists of coccygeal vertebrae, which are the remains of the bodies of the caudal vertebrae. In 61% of cases, the coccyx contains 4 vertebrae, in 30% - 3 vertebrae and in 9% - 5 vertebrae. Synostosis of the coccygeal vertebrae begins at the age of 12-14 years and goes from the bottom up. The distal vertebrae are usually fused together after 40 years. The connection between the bodies of the 5th sacral spine and the 1st coccygeal spine occurs through the intervertebral disc, which allows the coccyx to deviate backward (for example, during labor). However, assimilation in the vertebrae of the sacrococcygeal region is not uncommon, and the last sacral vertebra can be osseously fused with the coccygeal vertebra on one or both sides. At the same time, the coccygeal vertebrae are connected to each other by means of synchondrosis.

In old age, especially in men, all coccygeal vertebrae, except the first, fuse. In women, the coccyx is located more superficially than in men, which is due to the anatomical features of the pelvis (increased forward tilt). A stable connection between the coccyx and the sacrum is also achieved through the continuation of the anterior and posterior longitudinal, as well as lateral ligaments (lig. sacrococcygeal).

Symptoms of coccygodynia

Coccygodynia is characterized by a complex of disorders, which includes: pain in the coccyx, mental disorders, syndromes of the articular and pelvic ring, ligament-fascial syndrome, syndrome of internal organs, small pelvis and abdominal cavity, disimmunoses, vegetative disorders. The first four signs are detected during the disease constantly (obligatory signs of coccygodynia), the last three - periodically (optional signs of coccygodynia).

The disease coccygodynia is characterized by persistent pain syndrome. Patients cannot accurately localize their pain sensations, indicating their mosaic nature. Most often, the pain in the coccyx is aching, bursting, pulling, sometimes burning. In some cases, the pain decreases or disappears when the patient is standing, lying down and intensifies when sitting, especially on a hard surface, when coughing and exercising. Because of the pain, patients are forced to sit on one half of the pelvis, their movements become cautious.

Mental disorders: the sleep-wake cycle is disrupted, autonomic disorders appear (headaches, sensations of heat in the abdomen, lower back, vasomotor disorders, etc.). Vague fears, anxiety, and internal restlessness appear.

Musculoskeletal disorders develop: pathological changes in the sacrococcygeal, sacroiliac and hip joints occur in most patients. In this case, kinetics suffers, the joints of the lower extremities are overloaded, a non-optimal motor stereotype arises (asymmetry of the support function when sitting is formed, biomechanical disorders of the pelvic ring, spinal deformities occur, gait changes).

Regional ligamentous-fascial pathology, displacement and dyskinesia of the pelvic organs occur.

With coccygodynia, functional disorders of the internal organs occur, primarily the pelvis, then the abdominal cavity. Among the disorders of the pelvic organs, dyskinesia of the rectum predominates, urological disorders occur in 25% of patients with coccygodynia. Often, these disorders are accompanied by vegetative disorders: shortness of breath, palpitations, dizziness, sensation of heat or cold, peripheral angiospasm, arterial dystonia.

Coccygodynia is characterized by seasonal exacerbations.