The coccyx is the terminal end of the spine, just inferior to the sacrum. The base of the coccyx articulates with the sacral apex via the sacrococcygeal junction.
The coccyx serves somewhat as a weight-bearing structure when a person is seated, thus completing the tripod of weight bearing composed of the coccyx and the bilateral ischium. The ischial weight-bearing surfaces are, more specifically, at the ischial tuberosities and inferior rami of the ischium. The coccyx bears more weight when the seated person is leaning backward; therefore, many patients with coccydynia sit leaning forward (flexing at the lumbosacral and hip regions), which shifts more of the weight to the bilateral ischium rather than the coccyx (see the images below). Alternatively, patients with coccydynia may sit leaning toward one side so that the body weight is exerted mainly on one ischial tuberosity or the other, with less pressure on the coccyx.
Once the coccyx pain has become chronic (persisting for more than 3-6 months), it may be less likely to resolve by natural recovery alone.
Patients with coccydynia often report severe and persistent pain that compromises functional activities requiring sitting and diminishes their quality of life.
The options of treatment include use of analgesics and adjustment of posture and sitting. If this line of management fails then further management is often more intrusive.
Manipulation of the coccyx has also been advocated. A randomized study in patients with chronic coccydynia found that 51 patients treated with intrarectal manipulation had good results almost twice as frequently as did the control group, as determined at 1 month (36% vs 20%, P = .075) and at 6 months (22% vs 12%, P = .18). The main predictors of a good outcome were a stable coccyx, shorter symptom duration, and traumatic origin. The authors concluded that intrarectal manipulation had “mild effectiveness” for chronic coccydynia.
One possible mechanism for persistent coccydynia is excessive activity or sensitivity of the ganglion impar which is usually located anterior to the sacrococcygeal junction. This can then create sympathetically maintained coccyx pain. Local injection of an anesthetic can effectively block the ganglion impar and thereby relieve coccyx pain. In a published report by Foye and colleagues, nerve blocks using local anesthetics with a fast onset (eg, lidocaine) were shown to provide substantial relief even by the time a patient sat up on the procedure table.
Surgical treatment for coccydynia includes coccygectomy, in the form of partial or complete surgical removal of the coccyx
Coccygectomy has been associated with relatively high rates of postoperative infection. A case series of 20 patients treated with total coccygectomy reported that 90% of the patients eventually felt improvement, but overall postoperative complications included 7 wound problems (thus more than one third of the patients)—4 patients with superficial infections and 3 patients with persistent drainage.