Why Your Hip Might Need Replacement
Hip replacement becomes necessary when the cartilage inside your hip joint wears down or breaks, causing bone to rub against bone. This damage creates pain, stiffness, and loss of movement that conservative treatments—physical therapy, anti-inflammatory medication, injections—can no longer control. The most common cause is osteoarthritis, a degenerative condition where the smooth cartilage lining your hip joint gradually thins over years or decades. Other conditions, injuries, and diseases can also damage the hip joint enough to require surgical replacement.
Your hip is a ball-and-socket joint: the rounded head of your thighbone (femur) sits inside a cup-shaped socket in your pelvis. Cartilage covers both surfaces, allowing smooth, nearly frictionless movement. When that cartilage erodes, the bone underneath becomes exposed and damaged. Once the damage reaches a certain point, your surgeon may recommend replacing the worn surfaces with artificial components made of metal, ceramic, or plastic.
Key Takeaways
- Osteoarthritis—the gradual wearing of cartilage over time—is the leading reason people need hip replacement, accounting for the majority of cases.
- Rheumatoid arthritis, avascular necrosis, and hip fractures can all damage the joint severely enough to require replacement even in younger people.
- Bone dysplasia (abnormal hip development) and previous hip surgery can increase your risk of needing replacement later in life.
- Your doctor will use X-rays and sometimes MRI to confirm joint damage and rule out conditions that might improve with other treatments first.
Osteoarthritis: The Most Common Cause
Osteoarthritis accounts for roughly 80 percent of hip replacements performed in the United States. It develops when the cartilage protecting your hip joint wears down over time. This can happen because of age, repetitive stress on the joint, excess body weight, or a previous hip injury that never fully healed. The cartilage loss is often gradual—you may have mild pain and stiffness for years before it becomes severe enough to interfere with daily life.
Risk factors for hip osteoarthritis include being over 50, having a family history of arthritis, previous hip surgery, and jobs or sports that put repeated stress on the hip. Women are slightly more likely to develop it than men. Once osteoarthritis reaches an advanced stage—where the cartilage is nearly gone and bone damage is visible on X-ray—hip replacement is often the most effective way to restore function and relieve pain.
Rheumatoid Arthritis and Other Inflammatory Conditions
Rheumatoid arthritis (RA) is an autoimmune disease where your immune system attacks the lining of your joints. Unlike osteoarthritis, which develops slowly, RA can damage cartilage and bone relatively quickly. It often affects both hips at the same time and tends to strike people in their 40s and 50s, sometimes younger. Even with modern medications that slow the disease, some people with RA still develop joint damage severe enough to require replacement.
Other inflammatory conditions that can lead to hip replacement include lupus, ankylosing spondylitis, and psoriatic arthritis. These diseases cause the body to attack joint tissue, leading to cartilage loss and bone erosion. Your rheumatologist and orthopedic surgeon work together to determine whether medication adjustments might slow further damage or whether replacement is the best option to restore mobility and reduce pain.
Avascular Necrosis: When Bone Dies
Avascular necrosis (also called osteonecrosis) occurs when the blood supply to the femoral head—the ball part of your hip joint—is cut off. Without blood flow, the bone tissue dies. The bone can collapse, destroying the hip joint surface. This condition can develop after a hip fracture, long-term corticosteroid use (for conditions like lupus or COPD), heavy alcohol use, or sickle cell disease. It can also happen without a clear cause.
Avascular necrosis often affects people younger than those with osteoarthritis—sometimes in their 30s or 40s. Early detection through MRI can sometimes allow surgeons to save the hip with a bone-grafting procedure, but once the bone has collapsed, hip replacement is usually necessary. The condition can progress rapidly, so imaging and close follow-up are important if you have risk factors.
Hip Fractures and Previous Injuries
A severe hip fracture—particularly a fracture of the femoral neck (the narrow section between the ball and the shaft of the thighbone)—can damage the blood supply to the femoral head or create joint damage that leads to arthritis years later. Some fractures are repaired with screws or plates rather than replacement, but if the fracture is complex or the blood supply is compromised, when ready replacement may be recommended.
Even fractures that heal well can set the stage for early osteoarthritis. The joint surface may not line up perfectly after healing, or cartilage damage at the time of injury may accelerate wear. Previous hip surgery—whether for fracture repair, arthroscopy, or other reasons—can also increase your risk of needing replacement later. Your surgeon will review your injury history and imaging to determine whether your current pain and loss of function are related to old damage.
Hip Dysplasia and Developmental Abnormalities
Hip dysplasia is an abnormality in how the hip joint develops, present from birth. In dysplasia, the socket is too shallow or positioned at an unusual angle, so it does not fully cover and support the femoral head. This misalignment puts extra stress on the cartilage, causing it to wear out faster than normal. People with hip dysplasia often develop arthritis in their 30s, 40s, or 50s—much earlier than those without the condition.
Hip dysplasia can be mild and go undiagnosed for years, or it can be caught in childhood and managed with bracing or corrective surgery. If you were treated for hip problems as a child, or if you have a family history of hip dysplasia, mention this to your doctor if you develop hip pain. Early diagnosis of dysplasia-related arthritis sometimes allows for joint-preserving surgery, but advanced cases do require replacement.
Other Conditions Leading to Hip Replacement
Several less common conditions can damage the hip joint enough to require replacement. Slipped capital femoral epiphysis (SCFE) occurs in adolescents when the ball of the hip slips out of position; if not treated promptly, it can lead to early arthritis. Legg-Calvé-Perthes disease, another childhood condition, causes the femoral head to lose blood supply temporarily, and can result in joint damage later in life.
Severe infections in the hip joint (septic arthritis), pigmented villonodular synovitis (a rare joint tumor), and severe muscle or ligament injuries can also destroy cartilage. Additionally, some people develop hip problems after spinal fusion surgery, because the fusion changes how forces are distributed through the pelvis and hip. Your doctor will review your complete medical history and imaging to identify the underlying cause of your hip damage.
How Doctors Confirm Hip Damage
Your doctor will start with a physical exam—checking your range of motion, listening for grinding or clicking, and observing how you walk. X-rays are the standard first imaging test; they show bone structure, cartilage loss, and bone spurs that form as arthritis progresses. If the diagnosis is unclear, your doctor may order an MRI, which shows cartilage, ligaments, and early bone damage that X-rays might miss.
Blood tests can help identify inflammatory conditions like rheumatoid arthritis or lupus. Your doctor may also ask about your pain pattern (worse in the morning, after activity, or constant), what activities make it better or worse, and how it affects your sleep and daily life. This information helps determine whether you have tried all non-surgical options and whether replacement is likely to improve your function. The decision to proceed with surgery is based on imaging findings combined with your symptoms and how much conservative treatments have helped.
Frequently Asked Questions
Can hip replacement be prevented if I have osteoarthritis?
You cannot reverse cartilage loss, but you may slow its progression with weight management, low-impact exercise, anti-inflammatory medication, and joint injections. Not everyone with osteoarthritis needs replacement—many people manage pain and maintain function with these approaches for years. Your doctor can help you understand your individual risk based on imaging and symptoms.
At what age do most people get hip replacement?
The average age is around 65 to 70, but it varies widely. People with osteoarthritis typically need replacement in their 60s or later, while those with rheumatoid arthritis, avascular necrosis, or hip dysplasia may need it in their 40s or 50s. Age alone does not determine whether you need replacement—your symptoms and imaging do.
If one hip needs replacement, will the other one eventually need it too?
Not necessarily. If you have osteoarthritis in both hips, they may progress at different rates. Inflammatory conditions like rheumatoid arthritis are more likely to affect both sides similarly. Your doctor will monitor both hips and discuss timing if both eventually need surgery.
Can I delay hip replacement if my doctor recommends it?
Yes, you can delay surgery if your pain is manageable and you can still do the activities that matter to you. However, waiting too long can sometimes make surgery more difficult if severe bone damage develops. Discuss the risks and benefits of waiting versus proceeding with your surgeon.
What happens if I don't get hip replacement when it's recommended?
You may experience worsening pain, increasing stiffness, and loss of mobility. Some people adapt by limiting activities, using a cane, or taking stronger pain medication. However, bone damage does not improve on its own, and waiting may eventually limit your options or make surgery more complex.