Coccydynia, Coccygodynia
Conditions
Keywords
Coccygodynia, Tailbone Pain, Coccygeal Pain, Extracorporeal Shock Wave Therapy, High-Intensity Laser Therapy, Coccydynia
Brief summary
This study compares shock wave therapy with high-intensity laser therapy for tailbone pain, also called coccydynia. It includes adults aged 18 to 65 years who have had tailbone pain for at least 3 months and continue to have symptoms despite previous standard treatments. The main question is whether the two treatments differ in how much they reduce tailbone pain while sitting. The main comparison will be between pain before treatment and pain 3 months after the final treatment session. The study will also examine earlier pain relief, daily activities, and sitting ability. Participants will be assigned by chance to one of two treatment groups. One group will receive 6 shock wave therapy sessions, with 2 sessions per week. The other group will receive 10 high-intensity laser therapy sessions, with 3 sessions per week. Both treatments will be applied to the tailbone area by an experienced physician. Participants will be assessed before the first treatment session and 1 and 3 months after the final treatment session. They will rate their overall tailbone pain and pain while sitting on scales from 0 to 10. They will also complete questionnaires about how pain affects daily activities. At follow-up visits, participants will report changes in their condition and satisfaction with treatment. The study will also record sitting duration, the ability to sit for 30 minutes, pain medicine use, the need for additional treatment, and any unwanted symptoms or medical problems.
Detailed description
This is a single-center, prospective, randomized, controlled, open-label, parallel-group study conducted at a private medical practice in Istanbul, Türkiye. The study compares extracorporeal shock wave therapy (ESWT) with high-intensity laser therapy (HILT) for pain, function, and clinical outcomes in adults with coccydynia. Eligible participants provide written informed consent and are randomly assigned in a 1:1 ratio to the ESWT or HILT group. Both treatments are administered to the coccygeal region by an experienced physician. Baseline demographic and clinical data include age, sex, height, weight, body mass index, occupation, symptom duration, trauma history, postpartum association, prolonged sitting at work, previous treatments, and analgesic use. Baseline assessments are performed before the first treatment session. Follow-up assessments are performed 1 and 3 months after completion of the assigned treatment course. For each participant, follow-up intervals are calculated from the date of the final treatment session, rather than from enrollment or the first treatment session. The primary outcome is the change in sitting-related coccygeal pain intensity on the 11-point Numeric Rating Scale (NRS-11) from pretreatment baseline to 3 months after the final treatment session. The primary comparison is the difference in mean change between the ESWT and HILT groups. Change is calculated as the follow-up score minus the baseline score, with negative values indicating pain reduction. Secondary assessments include the change in sitting-related pain at 1 month, changes in overall coccygeal pain at 1 and 3 months, functional limitations, patient-perceived improvement, treatment satisfaction, and sitting capacity. Assessment instruments include the Oswestry Disability Index (ODI), the Paris Functional Coccydynia Impact Questionnaire (PFCIQ), the Patient Global Impression of Change (PGIC), and a five-point Likert treatment satisfaction scale. Unsupported sitting duration and the ability to sit for 30 minutes are also recorded. Analgesic use, the need for additional treatment, and adverse events are documented during follow-up. An a priori sample size calculation was performed using G\*Power version 3.1.9 for a two-sided comparison of two independent means. The calculation used a standardized effect size of 0.8586162 derived from descriptive statistics reported in a published coccydynia trial, an alpha level of 0.05, 90% power, and an allocation ratio of 1:1. Under these assumptions, the minimum required sample size was 60 participants, with 30 participants per group. Statistical analyses will be performed using IBM SPSS Statistics version 27.0. Statistical significance will be set at p \< 0.05. The distribution of continuous variables will be assessed visually using histograms and Q-Q plots. Normally distributed continuous variables will be summarized as mean and standard deviation, non-normally distributed continuous variables as median with the first and third quartiles, and categorical variables as frequencies and percentages. Between-group comparisons of continuous variables will use Student's t-test or the Mann-Whitney U test, according to the distribution of the data. Categorical variables will be compared using the chi-square test or Fisher's exact test. Two-way repeated-measures analysis of variance will be used to evaluate within-group and between-group effects for normally distributed repeated measurements. The Friedman test will be used for non-normally distributed repeated measurements, and Cochran's Q test is planned for categorical comparisons in the repeated-measures analyses.
Interventions
DEVICEExtracorporeal Shock Wave Therapy
Extracorporeal shock wave therapy is applied to the painful area surrounding the coccyx. Approximately 2,000 pulses are delivered per session at a frequency of 8-9 Hz. Pressure is initially set at approximately 1.5 bar and is gradually increased according to the participant's tolerance, up to 2.5-3.0 bar.
High-intensity laser therapy using a 1064-nm Nd:YAG laser is applied to the coccygeal region in two phases. The analgesic phase is delivered at a frequency of 25 Hz and an energy density of 12 J/cm2 for approximately 4 minutes. This is followed by a biostimulatory phase at a frequency of 25 Hz and an energy density of 70 J/cm2 for approximately 5 minutes.
Sponsors
Ahmet Sümen
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
This is a single-center, two-arm, randomized, open-label, parallel-group study. Participants are assigned in a 1:1 ratio to receive either extracorporeal shock wave therapy (ESWT) or high-intensity laser therapy (HILT). Assessments are performed before treatment and 1 and 3 months after each participant's final treatment session.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Age 18 to 65 years. * Diagnosis of coccydynia. * Coccygeal pain persisting for at least 3 months. * Persistent symptoms despite previous standard treatments. * Voluntary agreement to participate and provision of written informed consent. * Ability to attend regular follow-up visits.
Exclusion criteria
* Recent coccygeal fracture or severe coccygeal dislocation. * An injection, interventional procedure, or similar treatment to the coccygeal region within the preceding 3 months. * Previous extracorporeal shock wave therapy (ESWT) or high-intensity laser therapy (HILT) for coccydynia. * Another significant condition that could explain the pain, such as lumbar disc herniation, nerve compression, or significant hip or lumbar disease. * Suspicion that the pain originates from a non-coccygeal source, including gastrointestinal, urinary, gynecological, infectious, or tumor-related causes. * History of spinal or pelvic surgery. * Severe neurological disease, active infection, cancer, a severe bleeding disorder, or pregnancy. * Another condition causing widespread pain, such as fibromyalgia. * Inability to attend regular follow-up visits.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Sitting-Related Coccygeal Pain on the Numeric Rating Scale at 3 Months After Treatment Completion | Baseline (before the first treatment session) and 3 months after the final treatment session | Sitting-related coccygeal pain is assessed using the 11-point Numeric Rating Scale (NRS-11), ranging from 0 to 10, with higher scores indicating more severe pain. Change is calculated as the score 3 months after the final treatment session minus the pretreatment baseline score. Negative change scores indicate pain reduction. The primary comparison is the difference in mean change between the extracorporeal shock wave therapy and high-intensity laser therapy groups. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Sitting-Related Coccygeal Pain on the Numeric Rating Scale at 1 Month After Treatment Completion | Baseline (before the first treatment session) and 1 month after the final treatment session | Sitting-related coccygeal pain is assessed using the 11-point Numeric Rating Scale (NRS-11), ranging from 0 to 10, with higher scores indicating more severe pain. Change is calculated as the score 1 month after the final treatment session minus the pretreatment baseline score. Negative change scores indicate pain reduction. |
| Change From Baseline in Overall Coccygeal Pain on the Numeric Rating Scale | Baseline (before the first treatment session), and 1 and 3 months after the final treatment session | Overall coccygeal pain is assessed separately from sitting-related pain using the 11-point Numeric Rating Scale (NRS-11), ranging from 0 to 10. Higher scores indicate more severe pain. Change is calculated separately at each follow-up as the follow-up score minus the pretreatment baseline score. Negative change scores indicate pain reduction. |
| Change From Baseline in Oswestry Disability Index Percentage Score | Baseline (before the first treatment session), and 1 and 3 months after the final treatment session | The Oswestry Disability Index (ODI) assesses pain-related disability across 10 sections, each scored from 0 to 5. The percentage score is calculated as the sum of section scores divided by five times the number of answered sections, multiplied by 100. Scores range from 0 to 100%, with higher scores indicating greater disability. Change is calculated separately at each follow-up as the follow-up percentage score minus the baseline percentage score. Changes are expressed in percentage points, with negative values indicating reduced disability. |
| Change From Baseline in Paris Functional Coccydynia Impact Questionnaire Score | Baseline (before the first treatment session), and 1 and 3 months after the final treatment session | The Paris Functional Coccydynia Impact Questionnaire (PFCIQ) assesses the impact of coccydynia during sitting, rising from sitting, standing or walking, traveling, and nighttime. In the five-item study form, item scores are summed and multiplied by 10 to obtain a total score from 0 to 100. Higher scores indicate greater symptom impact. Change is calculated separately at each follow-up as the follow-up score minus the baseline score. Negative changes indicate improvement. |
| Patient Global Impression of Change Score | 1 and 3 months after the final treatment session | The Patient Global Impression of Change (PGIC) is a single-item assessment of the participant's overall change in condition since treatment began. The study form uses seven response categories scored from -3 (very much worse) to +3 (very much improved), with 0 indicating no change. Higher scores indicate greater perceived improvement. The score is assessed at each follow-up; no pretreatment PGIC score is subtracted. |
| Treatment Satisfaction on a Five-Point Likert Scale | 1 and 3 months after the final treatment session | Participants rate their satisfaction with the assigned treatment using a five-point Likert scale: 1, not at all satisfied; 2, not satisfied; 3, undecided; 4, satisfied; and 5, very satisfied. Higher scores indicate greater treatment satisfaction. Satisfaction is assessed separately at each follow-up visit. |
| Change From Baseline in Unsupported Sitting Duration | Baseline (before the first treatment session), and 1 and 3 months after the final treatment session | Unsupported sitting duration is recorded in minutes. Change is calculated separately at each follow-up as the recorded follow-up duration minus the pretreatment baseline duration. Positive changes indicate an increase in sitting duration. |
| Percentage of Participants Able to Sit for 30 Minutes | Baseline (before the first treatment session), and 1 and 3 months after the final treatment session | The ability to sit for 30 minutes is recorded as yes or no at each assessment. The outcome is the percentage of participants with a yes response at each time point. |
| Percentage of Participants Using Analgesics | Baseline (before the first treatment session), and 1 and 3 months after the final treatment session | Analgesic use for coccygeal pain is recorded as yes or no at baseline and follow-up assessments. The outcome is the percentage of participants with analgesic use recorded as yes at each assessment. This is a binary measure, not a measure of dose or tablet count. |
| Percentage of Participants Requiring Additional Treatment | 1 and 3 months after the final treatment session | The need for additional treatment for coccydynia is recorded as yes or no at each follow-up assessment. The outcome is the percentage of participants with a documented need for additional treatment at each follow-up. This measure concerns treatment need rather than confirmation that an additional treatment was received. |
| Percentage of Participants With Adverse Events or Complications | From the first treatment session through 3 months after the final treatment session | The outcome is the percentage of participants with at least one adverse event or complication recorded during the observation period. The case report form records the presence or absence of an adverse event or complication. Each affected participant is counted once for this outcome, regardless of the number of events. |
Countries
Turkey (Türkiye)
Contacts
CONTACTAhmet Sümen, MD
Outcome results
None listed