Coccygodynia

Introduction

• Triggered by or occurs while sitting & is sometimes aggravated by arising from a seated position
• 5x more common in women compared with men
• Mean age onset 40 years

Aetiology

• Associated factors include:
  • Obesity
  • Antecedent trauma
  • Vaginal childbirth
• Above factors may lead to post-traumatic arthritis of sacrococcygeal joint & ununited fractures or dislocations of coccyx
• Differential diagnosis:
  • Lesions of lumbar disks
  • Arachnoiditis of lower sacral nerve roots
  • Tumors of coccyx or sacrum
  • Pilonidal cysts & sinuses
  • Peri-rectal abscesses

Clinical Evaluation

• Symptoms:
  • Onset of pain may be insidious
  • Localised in & around coccyx without significant low back pain or radiating or referred pain
  • May be relieved by sitting on legs or on either buttock
  • May feel a frequent need to defaecate or pain with defaecation
• Physical examination:
  • Coccyx palpated externally, & distal segment manipulated rectally to detect pain generated by motion of coccygeal segments.

Imaging

• Plain radiographs:
  • AP & lateral
• Dynamic radiographs:
  • Comparison standing & sitting lateral radiographic views
  • Normal coccyx pivots slightly (5 to 25°) either posterior or anterior with sitting & returns to its original position with standing
  • Abnormalities of coccygeal segments in seated views have anterior hypermobility >25°
  • Subluxation or posterior displacement of mobile segment of coccyx is seen when patient is seated
  • A spicule of distal tip is seen most commonly with an immobile coccyx (<5° of motion with sitting)

• Other investigations:
  • CT of sacrococcygeal region
  • MRI  can show inflammation or subluxxation
  • Technetium 99m bone scan
  • Relief with injection of local anaesthetic

 Management

• Non-operative:
  • NSAIDs
  • Analgesics
  • Rest
  • Hot baths
  • Cushion to protect coccygeal region from repetitive trauma
  • Injection methylprednisolone (40 mg) & bupivacaine (10 mL 0.25%) around side & tip of coccyx (60% cure rate), or into an inflamed sacrococcygeal joint, as shown by MRI
• Operative:
  • Indications
    • Significant disabling coccydynia with radiographic subluxation
    • Instability
    • Coccygeal spicule, particularly on the tip of an immobile coccyx
    • After non-operative management has failed
  • Technique
    • Bowel preparation day prior
    • Prophylactic antibiotics
    • Prone position with hips & knees flexed
    • Vertical incision over coccyx, extending from just above sacro-coccygeal joint into buttock crease without extending into perianal skin, through fascia & gluteus maximus, dissecting directly to bone
    • All segments removed & end of sacrum smoothed by rasp, rongeur, or burr

• • Results
    • 90% good to excellent results at 8 years
  • Complications
  • • Perineal contamination of wound resulting in infection (10%)

Summary