High Yield Overview
Coccyx Fractures
Tailbone Injury | Coccydynia
FallCommon Mechanism
ConservativeMost Treatment
5FFemale Preponderance
MonthsRecovery Time
Coccyx Injury Types
Acute Fracture
PatternDirect trauma. Displaced or non-displaced.
TreatmentConservative
Dislocation
PatternSacrococcygeal hypermobility/dislocation.
TreatmentConservative +/- Injection
Chronic Coccydynia
PatternPersistent pain after injury.
TreatmentInjections / Surgery
Critical Must-Knows
- Mechanism: Direct fall onto buttocks (sitting position). Childbirth. Repetitive trauma.
- Diagnosis: Clinical history and examination. X-ray confirms fracture/dislocation.
- Treatment: Conservative in vast majority. Cushion, NSAIDs, PT.
- Coccydynia: Persistent coccygeal pain. May require injections or, rarely, coccygectomy.
- Prognosis: Most resolve in 4-12 weeks. Small subset develop chronic pain.
Examiner's Pearls
- "Most coccyx fractures are managed conservatively.
- "5F: Female, Fat, Forty, Fall, Fracture (risk factors for coccyx injury/coccydynia).
- "Dynamic lateral X-ray (Sitting vs Standing) can assess mobility.
- "Coccygectomy is reserved for refractory coccydynia.
Clinical Imaging
Imaging Gallery
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Coccyx Fracture Pitfalls
Missed Other Injuries
Fall Assessment. A fall onto buttocks can also cause sacral fractures, vertebral compression fractures. Complete assessment.
Chronic Pain
Coccydynia. 10-20% develop chronic pain. Warn patients. May need injections or surgery.
Don't Order Routine X-ray
Limited Utility. X-ray often not needed if history is clear. Clinical diagnosis.
Surgery is Rare
Coccygectomy. Reserved for truly refractory cases after 6-12 months of failed conservative treatment.
At a Glance: Coccyx Injury
| Feature | Details |
|---|---|
| Mechanism | Direct fall onto buttocks, Childbirth |
| Pain Location | Tailbone (Sacrococcygeal junction) |
| Diagnosis | Clinical +/- X-ray |
| Treatment | Cushion, NSAIDs, Time |
| Chronic Pain | Coccydynia (10-20%) |
Mnemonic
5F5 F's of Coccydynia
F
Female
5x more common in women
F
Fat
Obesity is a risk factor
F
Forty
Peak age 40-50
F
Fall
Direct trauma mechanism
F
Fracture/Dislocation
Injury pattern
Memory Hook:Risk factors for coccyx problems.
Mnemonic
CRANKConservative Treatment
C
Cushion
Donut or wedge cushion for sitting
R
Rest
Avoid prolonged sitting
A
Analgesia
NSAIDs, Paracetamol
N
No Constipation
Stool softeners to reduce straining
K
Keep Moving
Gentle activity. Avoid bed rest.
Memory Hook:Conservative coccyx care.
Mnemonic
Sit vs StandDynamic X-ray
S
Sitting
Lateral X-ray in sitting position
V
Versus
Compare to...
S
Standing
Lateral X-ray in standing position
Memory Hook:Assess coccygeal mobility.
Overview and Epidemiology
Definition: Coccyx fractures and coccydynia (coccyx pain) result from trauma to the tailbone (coccyx). The coccyx is the terminal segment of the spine, formed by 3-5 fused vertebrae.
Epidemiology:
- Sex: 5x more common in females (shorter, more curved coccyx).
- Age: Peak 40-50 years.
- Risk Factors: Obesity, Female, Direct trauma, Childbirth.
Mechanisms:
- Direct Fall: Sitting position. Most common.
- Childbirth: Traumatic delivery. Coccyx can sublux or fracture.
- Repetitive Trauma: Cycling, Rowing.
- Idiopathic Coccydynia: Pain without clear trauma (often postural/degenerative).
Anatomy and Pathophysiology
Anatomy:
- Coccyx: 3-5 fused vertebral segments. Articulates with sacrum at Sacrococcygeal Joint.
- Attachments: Gluteus Maximus, Coccygeus, Levator Ani, Anococcygeal Ligament.
- Mobility: Normally has some flexion/extension at sacrococcygeal joint.
Pathophysiology:
- Acute Injury: Direct impact causes fracture or dislocation of coccyx.
- Inflammation: Local swelling and pain.
- Healing: Most heal with fibrous union over weeks to months.
- Chronic Coccydynia: Persistent pain due to:
- Malunion with abnormal angulation.
- Hypermobility or instability at sacrococcygeal joint.
- Degenerative changes.
- Referred pain (L5/S1, Sacroiliac).
Classification
Injury Types
- Fracture: Break in coccygeal segment.
- Dislocation: Displacement at sacrococcygeal or intercoccygeal joint.
- Fracture-Dislocation: Combined.
Distinction rarely changes management.
Clinical Assessment
History:
- Mechanism: Fall? Childbirth? Gradual onset?
- Pain: Worse with sitting (especially on hard surfaces), Leaning back, Defecation.
- Duration: Acute vs Chronic.
Physical Examination:
- Inspection: Bruising over sacrococcygeal area.
- Palpation: Point tenderness over coccyx (external). Tenderness on bimanual palpation (PR/PV combined with external).
- Coccygeal Mobility: Assess with PR exam. Pain with manipulation?
- Neurological Exam: Usually normal (coccyx does not contain cord).
- Rectal Exam: Exclude rectal pathology.
Investigations
Imaging (Often Not Needed):
- Clinical Diagnosis: If history is clear (fall, tailbone pain), imaging may not change management.
If Imaging Performed:
- Lateral X-ray (Coccyx): Shows fracture, dislocation, angulation.
- Dynamic Lateral X-rays: Sitting vs Standing. Assess mobility (greater than 25 degrees = Hypermobility).
- MRI: Rarely needed. For persistent pain (exclude tumor, infection).
Rule Out:
- Sacral fracture (if significant trauma).
- Pilonidal disease.
- Rectal pathology.
Management Algorithm
📊 Management Algorithm
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Conservative (Standard)
- Cushion: Donut or wedge cushion. Reduces pressure on coccyx when sitting.
- Analgesia: NSAIDs (first line). Paracetamol. Opioids rarely needed.
- Stool Softeners: Reduce straining during bowel movements.
- Activity Modification: Avoid prolonged sitting on hard surfaces.
- Physiotherapy: Pelvic floor exercises. Manual therapy.
- Time: Most resolve in 4-12 weeks.
90% resolve with conservative care.
Surgical Technique
Coccygectomy Technique
- Position: Prone (jack-knife or flat).
- Prophylaxis: Antibiotics. Bowel prep not usually needed.
- Incision: Midline longitudinal over coccyx.
- Dissection: Incise periosteum. Dissect subperiosteally. Identify sacrococcygeal joint.
- Excision: Divide at sacrococcygeal joint (or leave most proximal segment). Remove coccyx.
- Closure: Close periosteum if possible. Layered closure. Avoid dead space.
- Post-op: Wound care. Avoid sitting directly on wound.
Standard midline approach with careful subperiosteal dissection.
Complications
Complications
| Complication | Risk Factor | Management |
|---|---|---|
| Chronic Coccydynia | Severe injury / Malunion | Injections / Coccygectomy |
| Wound Infection (Post-op) | Proximity to anus | Antibiotics / Washout |
| Rectal Injury (Surgery) | Dissection error | Primary repair |
| Hematoma/Seroma | Inadequate hemostasis | Drainage |
| Persistent Pain (Post-op) | Nerve irritation | Reassurance / Injections |
Postoperative Care
After Coccygectomy:
- Wound care (close to anus - risk of infection).
- Avoid direct sitting on wound for 2-4 weeks (cushion).
- Antibiotics if infection concern.
- Stool softeners.
- Return to normal activity: 4-6 weeks.
Outcomes
- Conservative: 90% resolve in weeks to months.
- Coccygectomy: 70-90% significant improvement in refractory cases.
- Chronic Coccydynia: Minority have persistent issues.
Evidence Base
Coccydynia Natural History
Key Findings:
- Most coccydynia resolves spontaneously.
- 10-20% develop chronic pain.
- Dynamic X-ray can identify hypermobility.
Clinical Implication: Conservative is first-line. Most improve.
Limitation: Prospective observational
Ganglion Impar Block
Key Findings:
- Ganglion Impar block provides relief in coccydynia.
- Variable duration of relief.
- Consider before surgery.
Clinical Implication: Injections can be effective for refractory cases.
Limitation: Case series
Coccygectomy Outcomes
Key Findings:
- Coccygectomy successful in 70-90% of refractory cases.
- Complications include infection, wound issues.
- Select patients carefully.
Clinical Implication: Coccygectomy is effective for carefully selected patients.
Limitation: Retrospective
Dynamic X-ray
Key Findings:
- Dynamic (sitting/standing) X-ray assesses coccygeal mobility.
- Greater than 25 degrees movement = Hypermobility.
- Helps classify and guide treatment.
Clinical Implication: Use dynamic X-ray for chronic coccydynia workup.
Limitation: Descriptive
Conservative Management
Key Findings:
- Reviewed conservative management of coccydynia.
- Cushion, NSAIDs, PT effective in most.
- Surgery rarely needed.
Clinical Implication: Start conservative. Reserve surgery for failures.
Limitation: Retrospective
Viva Scenarios
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
VIVA SCENARIOStandard
The Fall on Ice
EXAMINER
"What is your diagnosis and management?"
EXCEPTIONAL ANSWER
**Likely Coccyx Fracture/Contusion.**
1. **History**: Direct fall onto buttocks. Tailbone pain.
2. **Examination**:
- Point tenderness over coccyx.
- No neurological deficit.
- Rule out sacral/lumbar injury if high-energy.
3. **Imaging**: Often not needed if history is clear. Lateral coccyx X-ray if diagnostic doubt.
4. **Management (Conservative)**:
- Cushion (donut or wedge) for sitting.
- NSAIDs for pain.
- Stool softeners.
- Activity modification (avoid hard chairs).
5. **Prognosis**: Most resolve in 4-12 weeks.
6. **Follow-up**: If pain persists past 3 months, consider dynamic X-ray and injections.
KEY POINTS TO SCORE
Clinical diagnosis
Conservative treatment standard
Cushion, NSAIDs
Most resolve in weeks
COMMON TRAPS
✗Ordering routine X-ray (not always needed)
✗Missing sacral fracture if high-energy
LIKELY FOLLOW-UPS
"What if pain persists at 6 months?"
"What is a Ganglion Impar block?"
VIVA SCENARIOStandard
The Chronic Tailbone Pain
EXAMINER
"What are your next steps?"
EXCEPTIONAL ANSWER
**Refractory Coccydynia. Consider Injections then Surgery.**
1. **Review History**: Confirm mechanism, duration, failed treatments.
2. **Examination**: Tenderness. Assess coccygeal mobility.
3. **Imaging**:
- Dynamic X-rays (Sitting/Standing): Hypermobility? Spur?
- MRI: Rule out other pathology.
4. **Next Steps**:
- *Injections*: Ganglion Impar block or Coccygeal steroid injection. May provide relief.
- *If Injections Fail*: Consider Coccygectomy.
5. **Coccygectomy**:
- Reserved for true failures.
- 70-90% success rate.
- Counsel about risks (infection, wound issues).
KEY POINTS TO SCORE
Dynamic X-ray for chronic cases
Injections before surgery
Coccygectomy for failures
70-90% success
COMMON TRAPS
✗Operating too early
✗Not trying injections first
LIKELY FOLLOW-UPS
"What is coccygectomy technique?"
"What are the risks of coccygectomy?"
VIVA SCENARIOStandard
The 5 F's
EXAMINER
"Describe the 5 F's."
EXCEPTIONAL ANSWER
**5 F's of Coccydynia.**
1. **Female**: 5 times more common in women. Shorter, more posteriorly curved coccyx.
2. **Fat (Obesity)**: Higher BMI increases risk.
- Paradox: Very lean patients also at risk (less cushioning).
3. **Forty (Age)**: Peak incidence 40-50 years.
4. **Fall**: Direct trauma is the most common mechanism.
5. **Fracture/Dislocation**: The injury pattern.
**Note**: Childbirth is also a significant risk factor in women.
KEY POINTS TO SCORE
Female: 5x more common
Obesity
Age 40-50
Direct trauma
Childbirth
COMMON TRAPS
✗Forgetting childbirth as a cause
✗Not knowing the 5 F's
LIKELY FOLLOW-UPS
"How is coccyx anatomy different in women?"
"What is the mechanism in childbirth?"
MCQ Practice Points
Mechanism
Q: What is the most common mechanism for coccyx fractures? A: Direct fall onto buttocks (sitting position).
Treatment
Q: What is the first-line treatment for acute coccyx fractures? A: Conservative - Cushion (donut or wedge), NSAIDs, Activity modification, Stool softeners.
Chronic Pain
Q: What percentage of coccyx injuries develop chronic coccydynia? A: 10-20%.
Dynamic X-ray
Q: What does dynamic lateral X-ray assess? A: Coccygeal mobility. Greater than 25 degrees movement between sitting and standing indicates hypermobility.
Surgery
Q: What is the surgical treatment for refractory coccydynia? A: Coccygectomy - Excision of the coccyx. Reserved for failures of 6-12 months of conservative treatment and injections.
Australian Context
- Common Presentation: ED and GP clinics. Most managed without specialist input.
- Specialist Referral: For refractory coccydynia (Spine surgeon, Pain specialist).
- Coccygectomy: Rarely performed. Select centers.
High-Yield Exam Summary
5 F's
- •Female (5x more common)
- •Fat (obesity is risk factor)
- •Forty (peak age 40-50)
- •Fall (direct trauma mechanism)
- •Fracture/Dislocation pattern
Treatment
- •Cushion (Donut/Wedge) for sitting
- •NSAIDs for pain control
- •Stool Softeners to reduce straining
- •Activity modification (avoid hard chairs)
- •Time heals most (4-12 weeks)
Chronic Coccydynia
- •Dynamic X-ray (sitting vs standing)
- •Hypermobility: greater than 25° movement
- •Ganglion Impar block first-line
- •Coccygectomy for failures after 6-12 months
- •70-90% success with coccygectomy
Key Numbers
- •90% conservative success rate
- •70-90% surgery success rate
- •10-20% develop chronic coccydynia
- •10-15% wound infection post-op
- •4-12 weeks typical recovery