Dr Maigne has written many papers on the subject of coccydynia and devised the dynamic x-ray method to improve diagnosis.
See Dr Maigne's website on coccydynia.
Contact details for Dr Maigne are on the List of doctors and specialists in France.
For me, the first treatment is an anti-inflammatory injection (steroid) in the affected joint, as demonstrated by the dynamic films. This can only be done under fluoroscopic control. The result occurs within one week and provides a two to four month relief in 60 to 70% of the patients and full recovery (at one year) in 30%. Despite there is a theoretical risk of local infection, I have performed more than 500 injections in 8 years without any problem. In 10% of the cases, there is a marked post-injection pain for a couple of days.
We have completed a study comparing three manual treatments (manipulation, massage of the pelvic muscles and stretching of these muscles) with a placebo. These treatments work in only 20% of the cases and are actually more efficacious than the placebo.
The last specific treatment is surgery. We have also a study published on this topic. Our success rate is 93% of good and excellent results, provided only patients with luxation or frank hypermobility are operated on. In other cases, the results are not so good. This is a difficult operation for the surgeon. The dissection of the bone has to be very careful and slow to avoid any damage which could compromise the result.
With my colleague, Pr Doursounian, a Parisian orthopaedic surgeon, we have shown that there is a " learning curve " for this surgery, the results being better when the surgeon becomes more skilled and experienced. And this is really the problem with the coccyx, a very rare operation for a basic surgeon.
The patient should not be forgotten, as it is demanding for him/her too : the first post operative month is achieved in a painful condition, and improvement is slow to come. It commonly takes 4 months (and sometimes 6 to 10) for a definitive result.
Jean-Yves Maigne, MD
I have treated more than 4000 patients suffering from coccydynia and published 18 scientific studies on that topic since 1990. Obviously, this condition is now better understood and managed than it was when I started to get interest in it, in the early '90s. Formerly a chronic and hopeless condition, regarded as a manifestation of hysteria by many clinicians, coccydynia is now treatable in more than 80% of the cases.
Such a progress can be attributed to a better diagnosis, better conservative cares and a better surgical technique.
A better diagnosis means that the causative mechanisms are now better understood. Coccydynia merely means that the pain comes from the area of the coccyx and that it is prompted by the sitting position. It cannot be considered as a sufficient diagnosis. In a recent past, the cause was still ignored, or confounded with the provoking factor which may be either a fall, a child delivery, a local traumatism or nothing, the disease beginning spontaneously. Sometimes, the pain appears after a weight loss, which is very evocative of a spicule. These factors are not a lesion. The true causative lesions can be observed on dynamic films, which were my first contribution in this field (1992). The patient must be X-rayed in the painful position (i.e. sitting) and the film compared to a standard, standing one. The basic lesions are dislocation and hypermobility, accounting for 50% of the cases. Coccygeal spicules are a deformity visible on either film, the spicule pointing downward and backward. It appears at 12-14 years of age, with the definitive ossification of the skeleton and may become symptomatic after a traumatism, a weight loss or for unknown causes. Some will never become symptomatic. They are best visualized on a CT scan or a MRI but the dynamic films point out a specific feature of a symptomatic spicule: the coccyx must be rigid, otherwise the spicule is not likely to become harmful, as a flexion of the coccyx would decrease its pressure against the subcutaneous tissues. Spicules account for 15% of the cases of coccydynia. Fractures, projected pain and calcifications are rare diagnoses. All these lesions are, for their vast majority, accompanied by an inflammation into the affected disc or around the spicule. The rest of the cases is comprised of coccyges with a normal mobility pattern and without spicule. Some respond positively to an intradiscal injection, meaning that inflammation is the causative lesion but in 15% of the cases, there is no clear diagnosis and theses cases are often very chronic.
Conservative cares are either injections or manual treatment. I described intradiscal injections in my first publication (1992) and apical injections, for spicules, in 2000. They work pretty well (60-70% of good and excellent results) but have not been studied in controlled studies. Very chronic cases do not respond as well as more recent ones. In case of failure (meaning that there is no inflammation), a manual treatment can be tried. The success rate depends on the cause of coccydynia. The best cases are coccyges with a normal mobility (0° to 25° of flexion) having failed to respond to an injection. In these cases, the success rate is between 35 and 40%. The treatment consist in stretching the muscles inserting on the coccyx, massaging the trigger points and manipulating the sacroiliac joints if necessary. A more general approach is sometimes useful, with a treatment of the whole spine and joints.
The surgical technique has been greatly improved by my colleague, Pr Doursounian, an orthopaedic surgeon working in Paris (Saint-Antoine hospital). The infection rate, which was around 10% of the cases in the medical literature, has dropped to 1% thanks to a specific perioperative protocol. The good indications remain dislocation and hypermobility. In a recent study, we added symptomatic spicules on this list. A positive response to an injection, even for a short time, increases the success rate which is around 90%.
But there is still a lot to do as far as research is cncerned. The role of the muscles levator ani is almost ignored and their functioning in coccydynia would need to be explored in depth. The anatomic favouring factors (anatomy of the pelvis and shape of the sacrum/coccyx) are not understood. They might prove important regarding coccydynia after a child delivery but also in many other cases. We are also currently evaluating a new surgical technique to improve our results.
There are not so many conditions affecting the musculoskeletal system which have benefitted of such improvements in their management in the past 20 years.