Hip Osteoarthritis: Joint Damage, Therapy, and Surgery

Hip osteoarthritis is a progressive condition in which the cartilage lining the hip joint gradually breaks down, eventually exposing the underlying bone and causing pain, stiffness, and loss of mobility. It affects roughly 1 in 10 adults over age 60 in Western populations, though the actual experience of the disease varies enormously from person to person. What makes hip osteoarthritis especially tricky is that the relationship between what shows up on an X-ray and what a person actually feels is surprisingly weak, and the path from early cartilage wear to a hip replacement is far from inevitable.

How the Joint Breaks Down

The hip is a ball-and-socket joint built to handle enormous loads, and the cartilage capping both surfaces is only a few millimeters thick. In osteoarthritis, the process starts with changes in the cells that maintain that cartilage. These cells begin producing enzymes that chew up the surrounding matrix faster than it can be repaired. Early on, the damage is driven mostly by this biochemical disruption. But once the cartilage loses its smooth, elastic surface, it becomes increasingly vulnerable to raw mechanical wear. Research on hip cartilage suggests that somewhere in the middle stages of the disease, mechanical destruction begins to outpace the biological breakdown, grinding through deeper layers faster than the cells themselves can shift into a degradative state.¹ By the final stage, erosion of the last sliver of cartilage down to bare bone may be largely mechanical rather than biological.

The bone beneath the cartilage plays a role too. Subchondral bone normally acts as a shock absorber, distributing the loads that cartilage transmits. When that bone remodels abnormally, its microstructure weakens and its mechanical properties deteriorate, which can accelerate cartilage loss from below.² This is one reason researchers have looked at whether medications that improve bone metabolism might slow osteoarthritis progression in certain patients.

Who Gets It and Why

Hip osteoarthritis is not simply a consequence of getting older. Age raises the risk, but genetics, body weight, joint shape, and the physical demands of your working life all feed into whether your hip cartilage wears down and how quickly.

A large twin study from Denmark estimated that about 47% of the variation in who ultimately needs a hip replacement can be attributed to genetic factors, with shared environment accounting for roughly another 21%.³ Genetic influence appears to grow stronger after age 60. Part of what’s inherited may be the shape of the hip joint itself. Siblings of people who’ve had severe hip osteoarthritis are more likely to have subtle structural abnormalities in their hips, even before symptoms appear.⁴

Body weight matters, though its influence on the hip is more modest than on the knee. A meta-analysis found that every five-unit increase in BMI raised hip osteoarthritis risk by about 11%.⁵ A Mendelian randomization study, which uses genetic variants to simulate the effect of higher BMI, confirmed the link: genetically predicted higher BMI was associated with increased hip osteoarthritis risk.⁶ A large population-based cohort showed that incidence rates for hip osteoarthritis roughly doubled when comparing people of normal weight to those with grade II obesity.⁷ Still, the weight effect on the hip is substantially smaller than on the knee, where rates jumped roughly fivefold across the same weight categories.

Occupational loading is another well-established risk factor. Reviews have found moderate-to-strong evidence that heavy lifting, when sustained over 10 to 20 years at loads of at least 10 to 20 kilograms, is associated with a clearly increased risk of hip osteoarthritis.⁸ Farmers face particularly high relative risks, and in the UK, hip osteoarthritis is a prescribed occupational disease for long-term agricultural workers.⁹ Even exposure to heavy lifting in young adulthood, between ages 18 and 30, has been linked to early structural changes in the hip visible on MRI years later.¹⁰

Joint Shape and Femoroacetabular Impingement

One of the most significant developments in understanding hip osteoarthritis over the past two decades is the recognition that subtle abnormalities in the shape of the hip joint can set the stage for cartilage damage. Femoroacetabular impingement syndrome (FAIS) occurs when a bump on the femoral head, an overly deep or angled socket, or both cause the bones to collide abnormally during movement. This has been increasingly recognized as a contributor to hip pain in younger adults and as a precursor to osteoarthritis later in life.¹¹

A recent prospective study put numbers to the risk: middle-aged individuals with FAIS had dramatically higher odds of developing radiographic hip osteoarthritis within 10 years. After adjusting for confounding factors, the odds ratio for developing any hip osteoarthritis was nearly 7, and for end-stage disease requiring a replacement, it was close to 48.¹² Those are striking numbers, and they have fueled debate about whether surgically correcting impingement in younger patients might prevent or delay osteoarthritis. The evidence on that question remains incomplete, but the association between abnormal joint shape and future cartilage destruction is well established.

Developmental hip dysplasia, a condition where the socket is too shallow to fully cover the femoral head, is another structural pathway. When dysplasia from childhood or adolescence goes untreated, it concentrates load on a smaller area of cartilage and can lead to early osteoarthritis in young adults.¹³

The Disconnect Between X-rays and Pain

Perhaps the most frustrating aspect of hip osteoarthritis, for patients and clinicians alike, is that imaging findings and symptoms often do not match. You can have a hip that looks terrible on an X-ray but causes little pain, or a hip that looks fairly normal on film but aches constantly.

A study using data from the Osteoarthritis Initiative found that among people with definite radiographic hip osteoarthritis, only about 24% reported frequent hip pain.¹⁴ A larger diagnostic study confirmed the same pattern across two major cohorts: most people with frequent hip pain did not have radiographic osteoarthritis, and most people with radiographic osteoarthritis did not have frequent hip pain.¹⁵ Korean population data showed an even more extreme split, with radiographic hip osteoarthritis prevalence at only about 1.1% and painful hip osteoarthritis at just 0.2%.¹⁶

This discordance means that diagnosis should not rely on X-rays alone. A systematic review in JAMA found that physical examination is often more informative than imaging. Decreased hip adduction and decreased internal rotation on examination were among the most useful findings for identifying osteoarthritis, while normal passive hip motion made the diagnosis less likely.¹⁷ Another study found that provocative internal rotation testing was more accurate than X-rays for diagnosing clinically meaningful hip osteoarthritis, as determined by response to a diagnostic injection.¹⁸ If your doctor orders an X-ray and tells you the arthritis is mild, that does not necessarily mean your pain is not real or not coming from the hip. And if the X-ray looks severe but you feel fine, there is no urgency to intervene.

How the Body Compensates During Walking

People with hip osteoarthritis instinctively change the way they walk to reduce load on the affected joint. Research shows that patients walk with less hip adduction (the thigh moving inward) and reduced abduction and rotation forces, which shifts the hip contact force to a more vertical direction and decreases overall loading.¹⁹ A meta-analysis confirmed that people with end-stage hip osteoarthritis walk with substantially lower forces in both the front-to-back and side-to-side planes compared to healthy controls, while those with milder disease walk more normally.²⁰

These compensations are protective in the short term but come at a cost. A weakened, underused hip abductor muscle and an altered gait can put extra stress on the lower back and opposite knee. Higher abnormal loading patterns during walking have been correlated with worse pain scores and more cartilage damage on MRI.²¹ This is one practical reason that guided exercise to maintain hip strength and movement quality is considered important even when the joint is deteriorating.

Exercise and Physical Therapy

Exercise is consistently recommended as a first-line treatment for hip osteoarthritis, and the evidence supports it, with some caveats worth understanding. A randomized controlled trial comparing supervised exercise therapy to both a control and a placebo group found that the exercise group achieved significantly greater pain reduction and functional improvement on standardized outcome measures than either comparison group.²² A pilot study reported a 30% decline in pain, a 20% gain in leg strength, and a 30% improvement in hip extension range of motion after 12 weeks of training.²³

However, one well-designed trial injected a note of humility. It compared a multimodal physical therapy program (manual therapy, exercise, education) to a convincing sham treatment and found that both groups improved substantially in pain and function, with no meaningful difference between them.²⁴ Both groups saw clinically relevant pain improvements. This does not mean exercise is useless; it may mean that the specific manual therapy techniques tested did not add value beyond the structured attention, movement, and expectation of improvement that both groups received. The consistent message across trials is that staying active and keeping the hip muscles strong helps, even if the precise recipe of exercises matters less than simply doing them.

Medications and Injections

For pain management, nonsteroidal anti-inflammatory drugs (NSAIDs) are the most effective oral option. A large network meta-analysis found that several NSAIDs at adequate doses reliably beat placebo for hip and knee osteoarthritis pain, with diclofenac and etoricoxib among the most effective.²⁵ NSAIDs outperform acetaminophen (paracetamol) for both resting and walking pain, though the advantage is modest, roughly 6 mm on a 100 mm pain scale.²⁶ Opioids, by contrast, showed a much worse safety profile: almost 90% of opioid interventions in that network meta-analysis were associated with increased adverse events compared to placebo, and over 80% showed higher dropout rates due to side effects.²⁷

Injections directly into the hip joint are another option. Corticosteroid injections can produce significant short-term pain relief, with the peak effect appearing at about two weeks, though the benefit tends to fade.²⁸ Hyaluronic acid injections also improve pain and function scores, and a systematic review found that high-molecular-weight preparations performed better than placebo or no treatment at the four-to-six-month mark.²⁹ Combining hyaluronic acid with a corticosteroid may give better results than hyaluronic acid alone, though the evidence base for that combination is still developing.³⁰

When the Hip Needs Replacing

Total hip replacement is one of the most successful operations in modern medicine. For people whose pain and disability have not responded adequately to conservative measures, the surgery reliably restores function and eliminates pain. And the implants are lasting longer than ever. A 2025 systematic review pooling data from nearly 1.9 million total hip replacements across eight national joint registries estimated survivorship at about 94% at 20 years and projected roughly 92% at 30 years.³¹ A separate long-term follow-up of ceramic-on-ceramic bearings reported 93% survival at 25 years.³² For someone in their early 60s, there is a very good chance the implant will outlast them.

The debate over surgical approach has quieted somewhat but remains relevant. A meta-analysis of randomized trials comparing the direct anterior approach (entering from the front of the hip) to the posterior approach (from behind) found that the anterior approach offered a slightly shorter hospital stay, about eight hours less, and somewhat better early functional scores in the first six months.³³ The posterior approach was consistently faster to perform, by about 16 minutes on average. Another meta-analysis found less pain in the first 72 hours with the anterior approach and a smaller incision, but no difference in complications or functional scores beyond 12 weeks.³⁴ The practical takeaway: the anterior approach may give a faster early recovery, but by a year out, outcomes even out regardless of which way the surgeon goes in. The surgeon’s experience with their chosen approach matters more than which approach they choose.

When Pain Persists After Surgery

About 1 in 10 people who receive a hip replacement continue to experience significant pain afterward, and a growing body of research points to the nervous system itself as a culprit. In some patients, prolonged pain before surgery leads to central sensitization, a state in which the spinal cord and brain amplify pain signals so that even normal inputs are perceived as painful. Studies have found that hip osteoarthritis patients with more widespread pain show signs of central sensitization, including heightened sensitivity at sites far from the hip, increased scores on questionnaires designed to detect nerve-type pain, and elevated pain catastrophizing.³⁵ Central sensitization inventory scores correlated with resting pain in hip osteoarthritis patients, even when controlling for other factors.³⁶

A study of over 300 hip replacement patients found that central sensitization and pain catastrophizing before surgery were independent risk factors for persistent postoperative pain, with about 12% of patients experiencing it.³⁷ This is clinically meaningful because it suggests that identifying and addressing these pain-processing patterns before surgery, through psychological support, pain education, or targeted medications, could improve outcomes. If you’ve been in pain for years and you notice it spreading beyond just the hip, or that the pain feels burning or electric rather than the familiar deep ache, it’s worth raising with your clinician before scheduling an operation.

Rapidly Progressive Hip Osteoarthritis

Most hip osteoarthritis unfolds over years or decades. But a rare and severe subtype, called rapidly progressive osteoarthritis of the hip (RPOH), can destroy the femoral head within months. It primarily affects older women, with a typical age around 77, and its cause remains unclear, though subchondral fractures and immune responses have been proposed as contributors.³⁸ Known risk factors include advanced age, obesity, intra-articular corticosteroid use, and long-term hemodialysis.

One distinguishing feature is the pattern of pain: patients with RPOH have severe pain during weight-bearing and active movement but may show a surprisingly normal range of motion on passive examination in the early stages. The diagnosis is usually made when repeat X-rays weeks or months apart show dramatic joint-space loss. Because the bone quality in these patients is often poor, surgery requires careful implant selection, but functional recovery after hip replacement is generally good.³⁹

Stem Cells and Platelet-Rich Plasma

Regenerative therapies are heavily marketed for hip osteoarthritis, but the evidence is still catching up to the enthusiasm. A scoping review of stem cell-based therapies for hip osteoarthritis found that all included studies reported significant improvements in pain and function, with pain reduction averaging somewhere between 30% and 50% on visual analog scales. Radiological results were mixed: one study found cartilage repair on MRI in about 60% of participants, while another found no evidence of structural change despite symptom improvement.⁴⁰ No severe adverse events were reported, which is reassuring, but the studies were generally small and lacked robust controls.

Platelet-rich plasma (PRP) injections have also attracted attention. A meta-analysis found that PRP significantly reduced pain compared to baseline, with the greatest effect at one to two months, but the improvement in function was limited to that same early window.⁴¹ When compared head-to-head against hyaluronic acid, PRP did not show a significant advantage.⁴² The authors of that systematic review concluded they could not recommend PRP for hip osteoarthritis based on available data. If a clinic is charging thousands of dollars for PRP or stem cell injections and promising to regrow your cartilage, the science does not yet support those claims.

Disparities in Who Gets Treatment

Access to hip replacement is not equal. A study of over 142,000 hip osteoarthritis diagnoses in the United States found that less than half proceeded to total hip replacement. After adjusting for other factors, Black patients had about half the odds of undergoing surgery compared to non-Hispanic white patients, and Hispanic patients had similarly reduced odds. Insurance type mattered as well: Medicaid patients had roughly half the odds of receiving a hip replacement compared to those with commercial insurance.⁴³ Greater social deprivation and having more medical comorbidities were also associated with lower odds of surgery. These gaps are not easily explained by differences in disease severity and likely reflect systemic barriers in healthcare access, referral patterns, and patient-provider communication. For a condition where surgery is highly effective, these disparities translate directly into preventable disability.