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Year : 2019  |  Volume : 2  |  Issue : 2  |  Page : 128-133

A clinical and radiological study of nontraumatic coccygodynia in Indian population

Department of Spine, Stavya Spine Hospital and Research Institute, Ahmedabad, Gujarat, India

Date of Web Publication23-Jul-2019

Correspondence Address:
Bharat R Dave
Stavya Spine Hospital and Research Institute, Ahmedabad, Gujarat
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/isj.isj_15_18

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Background: Nontraumatic coccygodynia is poorly understood. Dynamic radiographs help to identify a radiological lesion. This study was performed to evaluate these parameters and define a line of management. Materials and Methods: A total of 46 cases with nontraumatic coccygodynia and 46 controls who met the inclusion criteria were evaluated using dynamic radiographs between June 2015 and May 2017. Radiological parameters, such as sagittal movement of coccyx, intercoccygeal angle (ICA), base angle (BA), and angle of pelvic rotation (APR), were calculated and compared between cases and controls to identify the radiological lesion in cases. On the basis of clinico-radiological findings, a treatment algorithm for these patients was proposed. Results: A total of 46 cases and 46 controls were studied. The mean age was 41.8 years in cases and 40.6 years in controls. Body mass index (BMI) ranged from 19 to 33. Twenty-nine cases had BMI >25. Average visual analog scale score at initial presentation (6.9), at 6 weeks (4.7), and final follow-up (3.9) was noted. ICA ranged from 1° to 21° (mean 11.12°). BA ranged from 0° to 83° (mean 41.41°). APR ranged from 2° to 33° (mean 14.74°). Twenty-seven patients had a good relief with local hydrocortisone injection and manipulation, whereas nine cases needed coccygectomy. Conclusion: Dynamic radiographs help in defining the radiological parameters and planning treatment. The sagittal movement of extension, posterior subluxation, higher BA, and low APR are the radiological findings seen in patients of nontraumatic coccygodynia. Majority of patients respond to conservative management; however, few may need surgical intervention.

Keywords: Coccygectomy, dynamic radiographs, manipulation, nontraumatic coccygodynia

How to cite this article:
Dave BR, Bang PB, Degulmadi D, Samel P, Shah D, Krishnan A. A clinical and radiological study of nontraumatic coccygodynia in Indian population. Indian Spine J 2019;2:128-33

How to cite this URL:
Dave BR, Bang PB, Degulmadi D, Samel P, Shah D, Krishnan A. A clinical and radiological study of nontraumatic coccygodynia in Indian population. Indian Spine J [serial online] 2019 [cited 2023 Apr 1];2:128-33. Available from: https://www.isjonline.com/text.asp?2019/2/2/128/263272

  Introduction Top

Coccygodynia, defined as pain in the region of coccyx, was first introduced by Simpson in the year 1859.[1] In majority of the cases, pain occurs only in the sitting position. It is more prevalent in women as compared to that in men, and the mean age of presentation is around 40 years.[2] Common causes include trauma, which can be acute or chronic, hypermobile coccyx, osteomyelitis, tumor, or intercoccygeal disc degeneration.[3] Obesity and female gender are known risk factors for the development of coccygodynia.[4],[5] Much of the literature has focused on post-traumatic coccygodynia and its management.

Nontraumatic coccygodynia is poorly understood with many proposed hypotheses without confirmation. Dynamic radiographs give information regarding the changes in the mobility of coccyx. Subluxation, immobility, and hypermobility are noted to be abnormal findings. Various treatment modalities include conservative measures, such as cushions, manipulative exercises, and injection of local hydrocortisone (LHC) into painful area, and aggressive treatment such as coccygectomy. In majority of the patients, the pain persists and leads to chronic and debilitating pain.[4] The purpose of this study was an attempt to evaluate patients with nontraumatic coccygodynia using dynamic radiographs and also to define an algorithm of various treatment modalities.

  Materials and Methods Top

Between June 2015 and May 2017, 46 cases and 46 controls were analyzed prospectively with dynamic radiographs of coccyx. An institutional ethics committee approval was obtained. All the cases had disabling pain in coccyx with no history of significant trauma in the past. All the controls were age-matched hospital staff or healthy volunteers who had never experienced any pain in the lower back or in and around the coccyx. Patients with a history of trauma, infection, previous surgery in the back, and tumor were excluded. In each case, the following details were recorded: age, gender, body mass index (BMI), duration of pain (in months), type of seat (hard or soft) that makes the pain worse, pain on defecation, pain (transiently exacerbated or triggered) on passing from sitting to standing position, visual analog scale (VAS) score (at 0 week, 6 weeks, and final follow-up), and maximum pain-free sitting time (in minutes).

Radiological parameters

Dynamic radiographs were performed in all the cases and controls. The first radiograph was a standing lateral film. The second radiograph in cases was taken in the most painful sitting position. In controls, the second radiograph was taken after 1 min of sitting on a hard stool with back slightly extended position. The dynamic radiographs thus obtained were templated on to a transparent sheet and superimposed over a bright light source with both sacrum on top of each other to evaluate various radiological parameters. The intercoccygeal angle (ICA) was used as a measure of the sagittal movement of the coccyx on dynamic radiographs, calculated as the angle between the two intercoccygeal lines drawn that pass in the center of coccyx [Figure 1].[5] On the basis of ICA, patients were classified into neutral or immobile (ICA <5°), normal mobility (ICA between 5° and 25°), hypermobile (ICA >25°), and subluxation (either posterior or anterior) [Figure 2].[6] Cases with normal and hypermobility were further classified into flexion and extension depending on the sagittal movement of the coccyx [Figure 3]. The coccygeal angle of incidence also known as base angle (BA) is defined as the angle at which the coccyx strikes the seat when the subject is sitting down.[5] This angle is calculated between the standing intercoccygeal line and the horizontal sitting surface. The angle of pelvic rotation (APR) is used to measure the sagittal rotation of the sacrum when the subject is sitting down in the most painful position.[5] It is the angle formed between the two overlapped images as shown in figure. In cases with subluxation, ICA, APR, and BA were not calculated as the intercoccygeal line could not be drawn. All the angles were calculated on overlapped images [Figure 4] and compared between cases and controls.
Figure 1: (a) Intercoccygeal line drawn in standing. (b) Intercoccygeal line drawn in sitting

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Figure 2: (a and b) Normal radiographs of coccyx in standing and sitting. (c and e) Coccyx subluxating posteriorly. (d and f) Coccyx subluxating anteriorly

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Figure 3: (a and b) Coccyx showing the normal movement of flexion after sitting. (c and d) Coccyx showing the abnormal movement of extension after sitting

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Figure 4: Illustration of calculation of radiological parameters on overlapping standing image over sitting. Angle between “line a” and “line b” is intercoccygeal angle (ICA). Angle between “line b” and “line e” is base angle (BA). Angle between “line c” and “line d” is angle of pelvic rotation (APR)

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Treatment protocol

All cases at the first visit were given a combination of nonsteroidal anti-inflammatory drugs (NSAIDs) and pillow for a minimum of 6 weeks [Table 1]. The type of pillow was chosen based on the radiological finding of flexion or extension. All patients with flexion on sitting X-ray were given soft cushion, whereas those in extension were given high-density cushion with hole. Patients not relieved after 6–12 weeks were offered LHC injection in and around the tip of coccyx. Pillow and NSAIDs were continued in these patients and observed for another 6–12 weeks. Patients without any relief were subjected to coccygeal manipulation under general anesthesia (GA) combined with a repeat LHC injection. The last resort for unrelieved patients was coccygectomy. All the cases with minimum follow-up of 1 year were included in the study. Controls were also followed up with regard to any symptoms at the end of 1 year.
Table 1: Treatment protocol for patients of nontraumatic coccygodynia

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Statistical analysis

Descriptive statistics have been tabulated. Chi-square test has been used to find significant differences. In case of small frequencies, Fischer's Chi-square test has been used. Significance has been calculated based on P value. P < 0.05 has been taken as the cutoff value for determining significance.

  Results Top

A total of 46 cases (23 males and 23 females) and 46 controls (16 males and 30 females) were studied. The mean age was 41.8 years (19–76 years) in cases and 40.6 years (21–66 years) in controls. BMI ranged from 19 to 33 (average, 25.86). Twenty-nine cases (63.04%) had BMI >25. Clinical symptoms are tabulated in [Table 2]. Average VAS at initial presentation (6.9), at 6 weeks (4.7), and at final follow-up (3.9) was noted.
Table 2: Clinical profile of cases

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Cases and controls were classified into four groups based on ICA [Table 3]. ICA ranged from 1° to 21° (mean, 11.12°). Sagittal movement of extension (in normal and hypermobile group) was noted to be statistically significant (P < 0.05) in cases when compared to that in controls. Posterior subluxation was seen to be more common in both cases (n = 9/10) and controls (n = 3/3). BA ranged from 0° to 83° (mean, 41.41°). A total of 16 of 36 cases had BA more than average with 75% of them going into extension. APR ranged from 2° to 33° (mean, 14.74°). A total of 19 of 36 cases had APR less than average (14.74°), with 79% of them going into extension. Relationship of APR with BA with the sagittal movement of coccyx was noted [Table 4] and [[Table 5]. Nine patients had good relief with NSAIDs and pillow, one had relief with LHC alone. A total of 27 patients had a good relief with LHC and manipulation, whereas nine cases needed coccygectomy [Table 1].
Table 3: Classification based on intercoccygeal angle

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Table 4: Comparison of cases and controls based on base angle

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Table 5: Comparison of cases and controls based on angle of pelvic rotation

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  Discussion Top

Coccygodynia was initially described by Simpson as pain or discomfort localized around the bottom end of the spine and usually triggered by prolonged sitting.[1] Various factors have been proposed as the etiological factors for such pain, which include significant trauma, repetitive injury, after childbirth, local tumors, infection, disk degeneration, arachnoiditis of the lower sacral nerve roots, tumors of pilonidal cysts and sinuses, and perirectal abscesses of idiopathic nature.[3] The exact cause of nontraumatic coccygodynia is still not known, although female gender and obesity are considered as predisposing factors. Furthermore, it has been reported that psychological depression, neurosis, or hysteria magnifies the clinical symptoms.[7] Trauma has been identified as the most common cause of pain in and around coccyx and has been studied in detail by many authors.[3],[8],[9],[10],[11],[12] There is scanty extent of literature on nontraumatic coccygodynia. This study has been confined to assess the clinico-radiological findings and management in patients with nontraumatic coccygodynia.

Coccygodynia is more common in women with an average age of presentation at 40 years. The dissimilarity in the female and male pelvis anatomy was proposed by Duncan[13] to be the main reason behind this. Because of wider greater sciatic notch in women, the sacrum and coccyx are inclined more backward, making them more liable to injury. On the contrary, greater sciatic notch is narrower in men, leading to a forward inclination of the sacrum and coccyx. The greater inter-ischial tuberosity distance causing more pressure on the coccyx is another explanation for female preponderance.[13] Our study had equal number of male and female patients. Obesity has been identified as a contributory risk factor. It is postulated that lesser pelvic rotation and steeper angle between the tip of coccyx and seat while sitting down is the cause of pain in this group of patients.[5] Coccyx in these patients angulates more posteriorly while sitting, which makes it prone to injury. On the contrary, patient with thin built have a better pelvic rotation, and coccyx tends to be in optimal flexion while sitting, which protects it from the repeated trauma. Our study had 29 patients (63.04%) with BMI greater than 25. The most common clinical finding in patients with coccygodynia has been pain while standing from sitting position.[5] It most likely corresponds with the movement of coccyx going back to its neutral position. This finding has been observed in our study as 23 patients (50%) had pain during this movement. Majority of patients (70%) had sit to stand pain for less than 6 months, whereas this was not observed in patients with chronic coccygodynia.

Dynamic radiographs (sitting vs. standing) help in defining the radiological parameters and management of these patients. On the basis of ICA, 26 patients (56.52%) in our study belonged to the normal mobility group, whereas the rest were either immobile, hypermobile, or subluxated. Although majority of the cases and controls had normal mobility, the sagittal movement of coccyx in both these groups was reverse. It was observed that majority of cases had extension on sitting, whereas controls had flexion as shown in [Table 3]. Similar finding was observed in individuals with hypermobile coccyx. Maigne et al.[5] have reported that cases with hypermobility always go into flexion but our study had all the cases with hypermobility going into extension. This observation was further strengthened as all the controls with hypermobility had flexion. Coccyx going into extension while sitting makes it more liable for repetitive trauma. In subluxation group, posterior subluxation was more common than anterior as observed in many other studies.[5],[6],[14] APR and BA are other important parameters to look for. APR is directly proportional to tendency of coccyx to go in flexion. Lesser the APR more will be the tendency for extension, making patients more prone to develop coccygodynia. A total of 19 of 36 cases had APR less than average (14.74°), with 79% of them going into extension. BA, on the contrary, is inversely proportional to the tendency of coccyx to go in flexion. Lesser the BA more will be the flexion. Patients with higher BA are thus more prone to develop coccygodynia. Sixteen cases had BA more than average (41.41°) with 75% of them going into extension. Similar observation of relationship of BA and APR with sagittal movements of coccyx has been described by Maigne et al.[5]

On the basis of clinical and radiological findings, we followed a treatment protocol for our cases. All cases with nontraumatic coccygodynia underwent dynamic radiographs at first visit to classify them into one of the four groups as shown in [Table 3]. All patients were given NSAIDs and pillow for 6 weeks. Patients with coccyx going in extension and subluxation were offered a firm cushion with hole (high-density U foam), whereas those with flexion were given a soft cushion. The hole within the firm cushion accommodates the coccyx going into extension, thus protecting it from the repetitive trauma as extension of coccyx creates a painful point. Patients not responding to cushion and NSAIDs were then offered LHC injection in and around the tip of coccyx. NSAIDs and pillow were continued for another 6 weeks in these patients. Ganglion impar block technique is a known method of treatment; however, this technique has been reported to be associated with significant discomfort, tissue damage, high risk of rectal perforation, the risk of discitis, incidence of needle breakage, neuritis, and inadvertent injection of the neurolytic agent into the rectum.[15] In our institute, we have not postulated this technique as a treatment protocol.

Patients resistant to both the aforementioned modalities of treatment were considered for coccygeal manipulation under GA combined with injecting LHC in and around the tip of coccyx. Although the success rate with only LHC was poor, its combination with manipulation had good results in 70% cases. Similar results have been proposed by Wray et al.[16] where the combination of manipulation with LHC has shown to have better outcomes as compared to LHC alone. Three main techniques have been described for intrarectal manipulation: Thiele did levator ani, coccygeus, and piriformis massage; Mennell used repeated joint mobilization with circumduction of the coccyx; whereas, Maigne followed mobilization of the coccyx in extension with energetic levator ani stretching.[17],[18],[19] We followed the second technique with repeated flexion, extension, and circumduction for 5–10 times under GA. The purpose of manipulation is to relax the muscles around coccyx, which are in a painful tension.[14] It also helps in making coccyx more mobile so that the direct pressure while sitting on the coccyx is reduced significantly. Coccygectomy was the last resort for patients who did not show any improvement on conservative line of treatment. Duncan[13] and Wray et al.[16] reported 90% and 74% success rates, respectively, following surgery. Patients who underwent coccygectomy at our center had a significant relief as well. Wound dehiscence was a problem in three cases but was managed with regular dressings.

  Conclusion Top

Dynamic radiographs help in defining the radiological parameters and planning treatment. The sagittal movement of extension (ICA), posterior subluxation, higher BA, and low APR are the radiological findings seen in patients of nontraumatic coccygodynia. Patients of nontraumatic coccygodynia with normal dynamic radiographs represent the true idiopathic cases. These patients need stringent follow-up with manipulation giving the best results in patients with chronic persistent pain. Majority of patients respond to conservative management; however, few may need surgical intervention.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Simpson J. Coccygodynia and diseases and deformities of the coccyx. Medical Times Gazette 1859;40:1-7.  Back to cited text no. 1
Fogel GR, Cunningham PY 3rd, Esses SI. Coccygodynia: Evaluation and management. J Am Acad Orthop Surg 2004;12:49-54.  Back to cited text no. 2
Postacchini F, Massobrio M. Idiopathic coccygodynia. Analysis of fifty-one operative cases and a radiographic study of the normal coccyx. J Bone Joint Surg Am 1983;65:1116-24.  Back to cited text no. 3
Lirette LS, Chaiban G, Tolba R, Eissa H. Coccydynia: An overview of the anatomy, etiology, and treatment of coccyx pain. Ochsner J 2014;14:84-7.  Back to cited text no. 4
Maigne JY, Doursounian L, Chatellier G. Causes and mechanisms of common coccydynia: Role of body mass index and coccygeal trauma. Spine (Phila Pa 1976) 2000;25:3072-9.  Back to cited text no. 5
Maigne JY, Guedj S, Straus C. Idiopathic coccygodynia. Lateral roentgenograms in the sitting position and coccygeal discography. Spine (Phila Pa 1976) 1994;19:930-4.  Back to cited text no. 6
Nathan ST, Fisher BE, Roberts CS. Coccydynia: A review of pathoanatomy, aetiology, treatment and outcome. j Bone Joint Surg Br 2010;92:1622-7.  Back to cited text no. 7
Wood KB, Mehbod AA. Operative treatment for coccygodynia. j Spinal Disord Tech 2004;17:511-5.  Back to cited text no. 8
Key JA. Operative treatment of coccygodynia. J Bone Joint Surg Am 1937;19:759-64.  Back to cited text no. 9
Bayne O, Bateman JE, Cameron HU. The influence of etiology on the results of coccygectomy. Clin Orthop 1984;190:266-72.  Back to cited text no. 10
Edwards M. Trauma of the coccyx and coccygodynia. Am J Surg 1938;42:591-4.  Back to cited text no. 11
Grosso NP, van Dam BE. Total coccygectomy for the relief of coccygodynia: A retrospective review. J Spinal Disord 1995;8:328-30.  Back to cited text no. 12
Duncan GA. Painful coccyx. Arch Surg 1937;37:1088-104.  Back to cited text no. 13
Maigne JY, Chatellier G. Comparison of three manual coccydynia treatments: A pilot study. Spine (Phila Pa 1976) 2001;26:E479-83; discussion E484.  Back to cited text no. 14
Gonnade N, Mehta N, Khera PS, Kumar D, Rajagopal R, Sharma PK. Ganglion impar block in patients with chronic coccydynia. Indian J Radiol Imaging 2017;27:324-8.  Back to cited text no. 15
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Wray CC, Easom S, Hoskinson J. Coccydynia. Aetiology and treatment. j Bone Joint Surg Br 1991;73:335-8.  Back to cited text no. 16
Maigne JY, Chatellier G, Faou ML, Archambeau M. The treatment of chronic coccydynia with intrarectal manipulation: A randomized controlled study. Spine (Phila Pa 1976) 2006;31:E621-7.  Back to cited text no. 17
Thiele GH. Coccydynia and pain in the superior gluteal region and down the back of the thigh: Causation by tonic spasm of the levator ani, coccygeus and piriformis muscles and relief by massage of these muscles. JAMA 1937;109:1271-5.  Back to cited text no. 18
Mennell JB. The Science and Art of Joint Manipulation. London, UK: Churchill; 1949.  Back to cited text no. 19


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]

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