Can a Chronic Coccyx Fracture Cause Hip Pain?
Yes, a chronic coccyx fracture can cause hip pain, as documented in spinal cord injury patients where coccyx fractures were associated with painful symptoms extending to the hip, gluteal, and thigh regions.
Evidence Supporting the Connection
The most direct evidence comes from a study examining 26 patients with spinal cord injuries who presented with pain in the low back, hip, gluteal, or thigh regions 1. Notably, 34.62% of these patients had coccyx fractures, and those with coccyx fractures demonstrated significantly higher pain scores (both Sensory Pain Index and total McGill scores) compared to those without fractures. This study establishes that coccyx fractures can manifest as hip pain and affect the broader pain experience in the pelvic region 1.
Clinical Reasoning and Mechanism
The anatomical proximity of the coccyx to the hip and the interconnected nature of pelvic pain referral patterns explain this phenomenon. Pain from coccygeal pathology can radiate to:
- Hip region
- Gluteal area
- Thigh
- Lower back
The pain is not isolated to the tailbone itself but creates a regional pain syndrome affecting adjacent structures.
Diagnostic Approach
When evaluating a patient with hip pain and suspected coccyx involvement:
Initial imaging should include:
- AP pelvis and lateral femoral head-neck radiographs to evaluate the hip joint itself 2
- Dedicated coccyx X-rays (lateral view is most useful) 1
If initial radiographs are negative or equivocal:
- MRI without IV contrast is the best next test to screen for both hip pathology and evaluate soft tissue structures 2
- MRI can identify coccygeal fractures that may be missed on plain films 3
Key clinical test:
- A negative FADIR (flexion-adduction-internal rotation) test helps rule out primary hip joint pathology 4
- If FADIR is negative but pain persists, focus diagnostic attention on the coccyx and surrounding structures
Important Clinical Pitfalls
Underdiagnosis is common because coccyx fractures are frequently mistaken for routine postpartum discomfort, inflammation, or nonspecific coccydynia 3. One case report documented a patient suffering for 1.5 years before proper diagnosis 3.
Do not assume hip pain equals hip pathology. The ACR guidelines specifically address scenarios where chronic hip pain coexists with low back or pelvic pathology, recommending MRI to exclude the hip as the source 2. In your case, the reverse applies—exclude the coccyx as the source of apparent hip pain.
Correlation with chronicity matters. The duration of injury correlates with pain severity scores, meaning chronic coccyx fractures may produce progressively worsening or persistent hip/pelvic pain 1.
Management Implications
Once a coccyx fracture is identified as the pain source:
- Conservative management (analgesia, activity modification, physical therapy) is first-line 5, 6
- Refractory cases may benefit from interventional options including pulsed radiofrequency, extracorporeal shockwave therapy, local injections, or caudal blocks 5, 3
- Surgical excision (coccygectomy) is reserved for persistent cases unresponsive to conservative measures 3
The critical point: imaging must always be combined with the patient's symptoms and clinical signs, never used in isolation 4. A coccyx fracture on imaging in an asymptomatic patient is an incidental finding, but in the context of hip/pelvic pain, it becomes clinically significant.