Groin pain — pain in the crease where the thigh meets the lower abdomen — is one of the most misattributed symptoms in orthopedics. The hip joint sits directly behind the groin, and diseased hips send their pain there, not to the 'hip' area people point to on their side. But the groin is a crowded neighborhood: hernias, muscle strains, and referred spine pain all present there too. Here's how specialists actually sort them out.
The C-sign: the hip's calling card
Ask someone with true hip joint pain to show you where it hurts, and they often can't point with one finger — instead they cup a hand around the hip in a 'C' shape, thumb in the groin and fingers over the outer hip, saying the pain is 'deep inside.' This C-sign is so characteristic that experienced hip surgeons treat it as a strong pointer to intra-articular (inside-the-joint) pathology before any imaging.
The two big hip-joint causes of groin pain
1. Hip osteoarthritis
The classic in patients over 50: deep groin ache with walking and standing, stiffness after sitting, trouble with socks and shoes, and gradually shrinking walking distance. A standing pelvis X-ray usually confirms it.
2. Labral tears and femoroacetabular impingement (FAI)
The classic in patients between 20 and 45: sharp groin pain with deep squats, getting out of a car, prolonged sitting, or pivoting sports — sometimes with catching or clicking. The labrum (the socket's cartilage rim) tears when an abnormally shaped ball and socket pinch it repeatedly. X-rays can look near-normal; MRI is often needed to see the tear.
The FADIR test
In clinic, the examiner bends the hip to 90 degrees, then adds adduction and internal rotation (Flexion-ADduction-Internal Rotation). Reproducing the patient's deep groin pain suggests impingement or a labral tear. It's a sensitive screening test — a negative FADIR makes joint pathology less likely, while a positive one directs the next steps of the workup.
What else lives in the groin: the differential
Inguinal hernia
A bulge that appears with standing, coughing, or straining and may ache toward the end of the day. Key difference: hernia pain worsens with abdominal pressure (coughing, lifting), not with hip rotation. Sock test is normal. Hernias need a general surgeon, not an orthopedist.
Adductor (groin muscle) strain
Common in footballers and gym-goers after a sprint, kick, or wide lunge. Pain sits on the inner thigh near its origin and is reproduced by squeezing the knees together against resistance — a movement that leaves a true hip joint quiet. Tender to direct touch, unlike joint pain.
Referred lumbar spine pain
Upper lumbar nerve roots (L1-L3) can refer pain to the groin and front thigh. Clues: coexisting back pain, pain influenced by bending or sitting posture rather than hip movement, numbness or tingling, and a normal hip examination. This is the trap that catches patients from both directions — hips blamed on backs, and backs blamed on hips.
Other causes worth knowing
Hip stress fractures in runners and low bone density (groin pain with every step, needs urgent attention), avascular necrosis in patients with cortisone exposure, and — rarely — non-orthopedic causes like urinary stones or gynecological conditions when the pattern doesn't fit movement at all.
Why side and buttock pain usually ISN'T the hip joint
Pain directly over the outer hip bone that hurts when lying on that side is usually trochanteric bursitis or gluteal tendinopathy — soft-tissue problems around the joint, treated completely differently. Buttock pain most often traces to the lumbar spine, sacroiliac joint, or piriformis region. As a rule of thumb: the hip joint speaks through the groin; the tissues around it speak through the side; the spine speaks through the buttock. Exceptions exist, which is what the examination is for.
When to see a specialist
Book an assessment if groin pain has lasted more than 4-6 weeks, limits walking or sport, clicks or catches, or wakes you at night. Seek urgent care for groin pain with fever, inability to bear weight, or pain after a fall. The workup is usually simple: examination plus X-ray first, MRI only when the story suggests a labral tear, stress fracture, or early avascular necrosis.
Groin pain in a 35-year-old footballer and groin pain in a 65-year-old are usually two different diseases — a labral tear in one, arthritis in the other. What they share is the C-sign and a limited internal rotation on my couch. The examination still tells us more than any single scan. — Prof. Dr. Mohamed Kamal, Bone Art Clinic
Frequently Asked Questions
What is the C-sign for hip pain?
When asked where it hurts, patients with true hip joint pain often cup a hand around the hip in a 'C' shape — thumb in the groin, fingers on the outer hip — describing deep internal pain. It strongly suggests the pain source is inside the joint itself.
How do I know if my groin pain is a hernia or my hip?
Hernia pain worsens with coughing, straining, and lifting, and often comes with a visible or palpable bulge — hip rotation doesn't bother it. Hip joint pain worsens with rotation, deep flexion (squatting, car seats), and walking, with no bulge. When in doubt, an examination sorts it out quickly.
What is a hip labral tear and how is it diagnosed?
The labrum is the cartilage rim deepening the hip socket; it tears with repetitive impingement or twisting injuries, causing sharp groin pain, catching, and pain with deep squats or prolonged sitting. Diagnosis: positive FADIR test plus MRI (often with contrast). In Egypt in 2026, hip MRI typically costs EGP 3,000-6,000.
Is pain on the side of my hip a hip joint problem?
Usually not. Pain directly over the outer hip that hurts when lying on that side is typically trochanteric bursitis or gluteal tendinopathy — soft-tissue conditions around the joint. True hip joint problems announce themselves in the groin.
When is groin pain an emergency?
Seek urgent care for groin pain with fever, inability to put weight on the leg, pain after a significant fall, a hernia bulge that becomes hard and irreconcilably painful (possible strangulation), or sudden severe pain in a patient on long-term cortisone.
What does a hip assessment cost in Egypt in 2026?
A specialist consultation typically costs EGP 700-1,500, a pelvis/hip X-ray EGP 300-800, and MRI — needed only in selected cases — EGP 3,000-6,000. Most groin pain is diagnosed with the first two alone.