Introduction
Coccydynia is a common pain syndrome affecting the tailbone or coccyx. It often radiates to the lower sacrum and perineum and is seen more often in females than in males. Patients often give a history of a direct fall on the coccyx, although coccydynia can also be caused by trauma due to poor sitting mechanics or injury during a difficult childbirth. Pain can also arise from degeneration or abnormal mobility of the coccygeal discs and joints. Pain may be referred from the lumbar region or may be due to injury to the sacral nerve roots, spasm of the pelvic floor muscles, or inflammation of the soft tissues surrounding the coccyx (Montero-Cruz, 2018). The coccygeal area is not well vascularized, and the anatomy consists of bones, tendons, and ligaments. The cause of the pain is usually due to a strain of the sacrococcygeal ligament or fracture of the coccyx; less often, it is due to arthritis.
Symptoms are usually localized to the coccyx and worsen with prolonged sitting or standing, leaning back while sitting, or rising to a standing position. Pain can become debilitating (Montero-Cruz, 2018). Treatment initially involves analgesics, use of ergonomic devices such as foam donuts to relieve pressure from sitting on the coccyx, pelvic therapy, and manipulation therapy. Injections of corticosteroids are used by many doctors; however, steroids can inhibit healing in some patients. Surgical removal of the coccyx has been performed, but there is no evidence to support the use of coccygectomy. This procedure also carries a high risk of infection (14.75–16.6%) because of its proximity to the rectum and anal canal (Montero-Cruz, 2018; Hazazi, 2021).
Montero-Cruz (2018) states that PRP may be beneficial, but there are no published reports for the use of PRP for refractory coccydynia. It is reasonable to consider that PRP may be successful in coccydynia because PRP has been documented to reduce inflammation and heal damaged bone, ligaments, and tendons, all of which are part of the pathology of coccydynia. PRP has also been effective in treating chronic injuries.
Case 1
A 17-year-old obese girl (BMI of 42.2) with coccygeal pain was seen in a clinic. The pain was not due to injury but was exacerbated by sitting. She was initially treated with a steroid injection, but pain returned in one week. At the second visit, PRP was injected into the sacrococcygeal ligament. The patient reported a 70% improvement in pain and sitting tolerance at six weeks. By six months, she was pain-free and remained pain-free at the one-year follow-up visit (Sussman, 2020).
Case 2
A 40-year-old with coccyx pain for more than six months, who failed to respond to multiple steroid injections and radiofrequency treatments, presented to the clinic. The patient received three PRP injections. The patient reported about 30% pain reduction after the first injection, 70% pain reduction after the second injection, and 85% pain reduction after the third injection. At six months, the patient’s pain control was maintained without the use of regular pain medication.
Cases 3, 4, and 5
Three patients with coccygeal pain for greater than six months presented to this same clinic. Each failed conservative treatment, including steroid injections. PRP was offered as a single treatment with the option to repeat it at six to eight weeks if needed. The injections were given under ultrasound guidance. 3 mL of PRP were injected along the posterior aspect of the coccyx, and an additional 3 mL of PRP were injected along the anterior aspect of the coccyx. No contrast or anesthetic was used. No NSAID medications were used 10 days prior to or six weeks after the procedures.
The first case in this series is a 50-year-old female who presented with three years of coccygeal pain after a slip and fall on ice. She had transient improvement after a steroid injection. After a single PRP injection, the patient had initial soreness for two weeks and symptom resolution at eight weeks. Her baseline pain rating was ten, and pain was completely resolved after PRP at the 8, 12, and 24-month follow-ups.
The second case is a 64-year-old female with chronic tailbone pain following a fall downstairs. She had symptoms for 1 year. The pain was worse with sitting on firm surfaces. There were no radiographic abnormalities. Two ganglion blocks gave her 50–60% improvement for three weeks. Her pain rating prior to receiving PRP was 10/10. The pain rating improved to 2–3/10 at six weeks following PRP, which was about a 75% improvement from baseline. She received a second PRP injection at eight weeks and noted a 50% reduction in pain at six weeks that lasted for six months when pain level returned to baseline.
The third case is a 45-year-old female with chronic tailbone pain of five years duration following a motor vehicle accident. Radiology showed no fracture or displacement, but edema was seen on the anterior coccyx. Physical therapy, manipulation therapy, therapeutic injections of the coccyx, and ganglion impar region provided transient improvement. Prior to receiving PRP, her pain rating was 9/10 and improved to 2/20 at the eight-week follow-up. This improvement was maintained at the 12- and 24-month follow-ups.
The three patients experienced significant reduction in pain. There was an average of 75% improvement in pain at the six-to-eight-week follow-up. At six months, one patient had no change while two patients maintained the same reduction in pain for two years (Montero-Cruz, 2018).
Case Study 6
A 17-year-old female with six months of non-traumatic coccyx pain, aggravated by sitting, presented to the clinic. She received a single PRP injection and reported 70% improvement in pain and an increased tolerance for sitting after 70 weeks. Six months after the injection, she reported 100% improvement in pain and remained pain-free at the 12-month follow-up (PRP Med, 2023).
Conclusion
Some people with coccydynia respond to conservative treatment, but for those who do not, the pain can be debilitating. The available literature is supportive of PRP’s regenerative effect on chronic tendon injuries, ligaments, and bone. PRP is believed to improve coccydynia by assisting in the repair and healing of the underlying tendon, ligament, and/or bone injury to provide longer-lasting pain relief than is obtained from traditional therapies.
References
Sussman, W., Jerome, M., & Foster, L. (2021). Platelet-rich plasma for the treatment of coccydynia: A case report and review of regenerative medicine for coccydynia. Regenerative Medicine, 14(12). https://doi.org/10.2217/rme-2019-0102
Hazazi, A. (2021). Platelet-rich plasma for refractory coccydynia: A case report. Journal of Spine Practice, 1(1), 44-44.
Montero-Cruz, F., & Aydin, S. (2018). Platelet-rich plasma injection therapy for refractory coccydynia: A case series. Interventional Pain Management. https://www.ipmreportsjournal.com/current/pdf?article=MjE0&journal=11
PRP Med. PRP (Platelet Rich Plasma) treatment for coccygodynia. Retrieved 8/12/23 from https://prpmed.de/en/blog/news/prp-platelet-rich-plasma-treatment-for-coccygodynia.
