The Practice of Medicine, Lindsay and Blakiston, Philadelphia.
1898 Pages 840-842
The coccyx is formed of four small segments of bone, which may be regarded as rudimentary vertebrae. None of the segments have any spinal canal or intervertebral foramina. The first and largest division of the coccyx articulates with the lowest sacral vertebra: the last three coccygeal segments are usually anchylosed into a single bone.
The coccyx, or the tendinous expansions of the muscles and the fibrous tissue of the ligaments, will now and then be found the seat of severe pain of a neuralgic character; this affection being technically known as coccyalgia, or coccygodynia, or coccyodynia [from the cuckoo - because the coccyx is said to resemble the beak of this bird - and pain].
The causes of coccyodynia are usually blows, falls (especially tumbles down three or four stairs, when the bottom of the back strikes the edge of each stair), bruises produced by violent or prolonged horse-exercise, injuries inflicted during parturition, and so on. Moreover, whatever is capable of exciting inflammation in the muscular attachments to, and the fibrous tissues around the coccyx, may lead to this disease. Hence, we find it attributed to sitting on damp grass or cold stones, to the application of ice which has been used for checking uterine hemorrhage, as well as to mischief set up by unnecessarily severe operations about the rectum.
The symptoms are characteristic. They consist chiefly of great pain on sitting down or on rising from a chair; as well as on walking, and on defecation, &c. Indeed, whatever stretches the exceedingly tender structures attached to the coccyx, proves to be the source of considerable suffering. Many of the patients can only sit on one hip. They get from the sitting to the erect posture in a slow and deliberate manner; so as to avoid any strain on the coccygeal ligaments, and to prevent any play of the sacro-coccygeal articulation.
The tenderness on pressure is usually well-marked; while sometimes the slightest touch of the tip of the bone causes agony. The tenderness is also aggravated by sexual intercourse, and frequently by the menstrual flow. Occasionally, coccyodynia is accompanied by some chronic uterine or ovarian disease. Frequently the general health is depressed; while there is also no little anxiety, especially where advice has been had without any relief following.
The treatment ought to be prompt. It is merely a waste of time to try the effect of warm baths, sedative applications, opiate plasters, iodine liniments, or small blisters over the seat of pain. India-rubber cushions, to keep off pressure, are useless. Leeches do harm. Even the subcutaneous injection of morphia, or of atropine, will only give temporary relief. The only hope of effecting a radical cure is by operation.
Now the most simple proceeding, but, unfortunately, the least certain, consists in the subcutaneous division of the muscular fibres and ligaments and fasciae connected with the coccyx, so as to set the bone at rest. The operation, as suggested by Sir James Simpson, is performed with a tenotomy knife, which must be strong enough to bear manipulation without breaking. The blade of this introduced through the skin over the middle of the bone, is to be deliberately passed all round, and close to its surface and edges, as well as over its tip. The disengagement of the coccyx from the surrounding soft textures thus effected, is usually at once attended with complete relief to the pain. But this apparent cure does not always prove real. Either because the tissues again become adherent to the bone, or in consequence of there being some mischief in the osseous structure itself, the pain returns. Under such circumstances the only plan is to amputate the whole, or simply the last two segments of the bone itself.
The coccyx was first extirpated for the relief of neuralgia by Dr. I. C. Nott, of Mobile, Alabama (1). Subsequently, in June, 1859, this operation was had recourse to by Sir James Y. Simpson, after he had failed to effect a cure by the subcutaneous division of the muscles and tendons and ligaments attached to the coccyx (2). Following in the steps of these gentlemen, I have removed the coccyx in a few instances with complete success. The operation is in no way difficult; it being merely necessary to make an incision about two inches long over the bone, and then having fairly exposed this structure to sever the soft attachments all round it, dividing it between its segments with the bone pliers. One or two vessels may need a ligature; and then the edges of the wound are to be brought together by a couple of sutures. With rest and water-dressing, union will be found complete in a few days. The relief which is thus afforded is sometimes surprising. The general health improves, and all mental anxiety ceases as the feeling is experienced that a most troublesome source of suffering has been removed.
In close proximity to the tip of the coccyx, and attached to it by a fine pedicle, is a minute body which has been the subject of some discussion. It is found as a roundish body about the size of a small shot, or as four or five or more isolated corpuscles connected by fine vessels. This body, discovered by Professor Luschka, of Tubingen, has been regarded by different observers as a gland; as a kind of heart, to strengthen the circulation in the superjacent skin; as the vestige of an organ, only of use during foetal life; and as the homologue of some structure in the lower animals. This last theory is held by Dr. W. M. Banks, after a thorough investigation of the subject, to be the only rational explanation; while this gentleman believes with Julius Arnold that the body is a vascular appendage of the middle sacral artery, and not a gland as supposed by Luschka. Dr. Banks says (3) that this coccygeal body hangs from the very end of the middle sacral artery, and is formed by the union into a glomerulus of from two to six clumps of arterial twigs, with saccular dilatations upon them; the whole being bound into one mass by a sort of capsule of connective tissue, which sends in processes between them. The body has no physiological functions; and nothing is known with regard to its pathology. Perhaps, however, it may act as a starting-point for those cysto-sarcomatous tumors now and then found in the perineum. There is probably no connection between this arterial appendage and coccyodynia; notwithstanding Luschka's opinion, that this affection consisted essentially of an inflammation of the little coccygeal body.
There are other congenital coccygeal tumors occasionally met with, which on dissection have been found to contain rudimentary bones and muscles and teeth. Such growths have sometimes been formed by the inclusion of one foetus within another: that is to say, two ovules having been impregnated, after a time the development of one has become arrested. Either before or just as this has happened, however, the blighted foetus has become attached to the healthy body; and thus has got included in its structure (4).
1. Quoted from the "New Orleans Medical Journal," May, 1844, by the American Journal of the Medical Sciences, New Series, vol. viii, p. 644. Philadelphia, 1844.
2. The Medical Times and Gazette, p. 1. London, July 2d, 1869.
3. The Glasgow Medical Journal, p. 14. New Series, No. 13. May, 1867.
4. Compare with the Author's Signs and Diseases of Pregnancy. Second edition, p. 170. London, 1867.