In 1859 Simpson, an Edinburgh surgeon, discussed the causes and treatment of coccyx pain, including an operation that he had devised to separate the coccyx from all the surrounding muscles, tendons, and ligaments. His reasoning was that coccyx pain was often caused by the coccyx being pulled out of position by the muscles attached to it.
He did not state the number of cases he had treated this way, but said that it was successful in almost every case, and in only one or two cases had he had to remove the coccyx.
He described the procedure as follows: "To effect this, you must introduce a tenotomy knife underneath the skin, at a short distance from the tip of the coccyx, pass it along the posterior aspect of the bone, and then divide the muscular and tendinous attachments, first on one side and then on the other, and finally all round the tip of it. It is not in every case necessary to make such a free division as I have indicated. In some instances division of the fibres of the gluteus maximus of one or the other side will suffice, or detachment from the coccyx of the sphincter and levator ani may be all that is requisite for a cure. This simple operation is easy and rapid of performance, like other examples of subcutaneous surgery is not attended with bleeding, and is attended with no great degree of suffering; and the result is in almost every case instant relief of the pain, and in most cases a perfect and permanent cure of the disease."
On one occasion, Simpson's knife broke inside the patient: "I was dividing the last fibres of the coccygeal attachments, when the slender knife gave way, and broke among the dense structures. I told the patient of it, and she at once raised herself up in alarm to hear of the calamity; but before I had done telling her of what had happened, she had had time in sitting up to discover that she had been cured of her disease, and rejoiced at the discovery. She quickly replied, "Oh! never mind; my pain is gone - let the knife remain." And there, for aught I know, it remains to this day." Presumably this operation had been performed without anesthetic.
The operation was also used later by Thomas, a New York surgeon. He described it thus: "The first operation is performed subcutaneously by an ordinary tenotomy knife. This is passed under the skin at the lowest point of the coccyx, turned flat, and carried up between the skin and cellular tissue until its point reaches the sacro-coccygeal junction. Then it is turned so that in withdrawing it an incision may be made which entirely frees the coccyx from muscular attachments. The knife is then introduced on the other side so as to repeat the section there. As is usually the case in subcutaneous operations, no hemorrhage occurs unless some large vessel be injured. Complete convalescence is rapid."
However, in 1886, Whitehead, reported that he had carried out 7 coccygectomies, with immediate and complete cure of the disease in all cases. He claimed that coccygectomy was simple, without danger and more easily performed than separation of the muscles, and should be performed in all cases where non-operative had failed.
Despite later evidence of problems and failures of coccygectomy in some cases, this advice seems to have been followed, and the subcutaneous operation fell out of fashion.