Intermittent Hip Pain: Differential Diagnosis
Intermittent hip pain in adults most commonly arises from osteoarthritis, soft tissue injuries (trochanteric bursitis, tendinopathy), labral tears with femoroacetabular impingement, or referred pain from the lumbar spine, sacroiliac joints, or knee. 1
Algorithmic Approach to Diagnosis
Step 1: Localize the Pain Pattern
The anatomic location of pain narrows the differential significantly:
Anterior hip/groin pain suggests:
- Intra-articular pathology: Labral tears, femoroacetabular impingement (FAI), osteoarthritis, or ligamentum teres injuries 1, 2
- Extra-articular causes: Hip flexor injuries, iliopsoas bursitis, athletic pubalgia 1, 3
- Referred pain: Intra-abdominal or intrapelvic pathology 2
Lateral hip pain indicates:
- Greater trochanteric pain syndrome (most common cause) including gluteus medius tendinopathy/tears, trochanteric bursitis, or iliotibial band friction 2, 3
Posterior hip pain suggests:
- Lumbar spine pathology (referred pain)
- Deep gluteal syndrome with sciatic nerve entrapment
- Ischiofemoral impingement
- Hamstring tendinopathy 2, 3
Step 2: Identify Key Clinical Features
For FAI and labral tears (younger adults <50 years):
- Pain triggered by hip flexion activities (sitting in low seats, squatting, sporting activities requiring repeated flexion) 4
- Pain with internal rotation at 70-110° of flexion on examination 4
- Intermittent mechanical symptoms (clicking, catching, locking) 3
For osteoarthritis (older adults):
- Gradual onset, worse with weight-bearing
- Morning stiffness <30 minutes
- Reduced range of motion 1
For soft tissue injuries:
- Pain localized to specific tendons or bursae
- Reproducible with palpation or specific movements 1
Step 3: Initial Imaging Strategy
Radiographs of the pelvis and hip are mandatory as the first imaging test 1. This includes:
- Anteroposterior (AP) pelvis view
- Lateral femoral head-neck view (Dunn, frog-leg, or cross-table view) 5
These radiographs screen for osteoarthritis, bone tumors, dysplasia, and FAI morphology.
Step 4: Advanced Imaging When Radiographs Are Negative/Equivocal
If soft tissue pathology is suspected (tendonitis, bursitis):
- MRI hip without IV contrast or ultrasound are appropriate 1
- MRI evaluates iliopsoas bursitis, trochanteric bursitis, abductor tendinosis/tears, hamstring injuries 1
- Ultrasound is useful for superficial structures and can guide diagnostic/therapeutic injections 1
If labral tear or FAI is suspected:
- MRI without contrast, MR arthrography, or CT arthrography 1
- MR arthrography provides superior visualization of labral tears 1
If infection is considered with suspected arthritis:
- MRI with or without IV contrast or hip aspiration 1
Step 5: Diagnostic Injections
Image-guided anesthetic injections (with or without corticosteroids) help confirm the pain source 1:
- Intra-articular injection relieving pain confirms joint pathology
- Trochanteric injection confirms trochanteric pain syndrome
- Iliopsoas injection confirms iliopsoas-related pain
Common Pitfalls to Avoid
Never diagnose based on imaging alone - Incidental findings are common in asymptomatic individuals 5. Always correlate imaging with symptoms and clinical examination.
Don't overlook referred pain - Always examine the lumbar spine, sacroiliac joints, and knee as potential pain sources 1
Recognize that imaging has limited diagnostic utility - Even advanced imaging shows only small to moderate shifts in post-test probability for most hip conditions 5
Don't skip radiographs - Despite being basic, radiographs may be the only imaging needed for osteoarthritis or advanced osteonecrosis and guide selection of additional tests 1
Most Likely Diagnoses by Age and Activity
Young, active adults (<50 years): FAI with labral tears, athletic pubalgia, stress fractures 2, 4
Middle-aged adults: Early osteoarthritis, tendinopathy, greater trochanteric pain syndrome 2
Older adults (>50 years): Osteoarthritis (most common), gluteus medius tears, referred lumbar spine pain 1, 2