Radiology glossary

What does "hip osteoarthritis" mean on your scan?

Part of: Hip findings, explained

Full explainer: Hip Osteoarthritis — What It Means on Your Report

The hip joint's cartilage has worn down — the ball-and-socket joint is showing the classic changes of osteoarthritis. The hip is a deep, stable joint where the thigh bone's ball sits in the pelvis's socket, cushioned by smooth cartilage; with age, injury, or certain hip shapes, that cartilage thins, the joint space narrows, small bone spurs form around the socket's rim, and the bone beneath can harden or develop small cysts. Radiologists often grade the severity from mild joint space narrowing to advanced bone-on-bone wear. Hip arthritis is a leading cause of groin pain in older adults — the pain is typically felt deep in the groin or front of the thigh rather than on the side of the hip, and it often starts as stiffness or aching with activity that eases with rest. But the X-ray grade and the symptoms do not always agree: some people with advanced wear function reasonably, while others with mild changes hurt significantly. The images stage the wear; your pain, stiffness, and daily limitations stage the problem.

What it means on CT

CT shows the bony changes of hip arthritis in fine detail — the exact pattern of joint space narrowing, osteophyte size and location, subchondral cysts, and bone density — and it is the preferred test for precise measurements when joint replacement is being considered. It shows the bone's architecture better than any other test. What it adds less is the soft-tissue picture: cartilage quality, marrow irritation, and labral condition are MRI's domain.

What radiologists look at next

For hip osteoarthritis, the radiologist grades the classic X-ray features: the degree of joint space narrowing and whether it is uniform or worst in one zone, the size and location of osteophytes, subchondral sclerosis, and any cysts in the bone. They check for deformities that accelerate wear — such as impingement shapes or old injuries — and note the alignment of the joint. On MRI they add the cartilage's condition, marrow edema indicating active irritation, labral tears, and effusion size. The complete wear profile lets your doctor match the anatomy to your symptoms and function.

Where it commonly shows up

• hip
• right hip
• left hip
• groin
• acetabulum

Questions to ask your doctor

• How advanced is the arthritis — mild, moderate, or severe?
• Could my groin pain be coming from the hip joint itself?
• Is there anything besides arthritis contributing — labrum, tendons, bursitis?
• What can I do to keep the joint working well?
• At what point would joint replacement be discussed?

Common questions

What does hip arthritis feel like?

Typically a deep ache in the groin or front of the thigh — not the side of the hip, which more often points to tendon or bursa problems. It often starts as stiffness after sitting, aching with walking or stairs, and reduced range of motion, like difficulty putting on shoes. Your doctor can test whether your pain pattern fits the joint.

Will hip arthritis keep getting worse?

Osteoarthritis tends to progress slowly over years, but the pace varies enormously — many people stay stable for long periods, and symptoms can wax and wane. Staying active, maintaining a healthy weight, and strengthening the surrounding muscles are the standard advice for keeping the joint functional. Your doctor tracks it with periodic X-rays and your own report of how you are doing.

Does everyone with hip arthritis need a hip replacement?

No — many people never do. Replacement is considered when pain and stiffness substantially limit daily life despite simpler measures, not at a particular X-ray grade. Plenty of people with advanced-looking X-rays function acceptably, and plenty with mild X-rays struggle. The decision is about your life, made with your doctor.

Related conditions

• Osteoarthritis — What It Means on Your Report
• Labral Tear — What It Means on Your Report
• Joint Effusion — What It Means on Your Report