The hip cannot be reached reliably by feel, and half of hip pain is not the hip.

PRP FOR THE HIP

Hip osteoarthritis is often mislocated by the people who have it. The classic presentation is groin pain and a loss of internal rotation, not pain over the outside of the hip — that is usually the gluteal tendons, a different problem with a different treatment.

Why the hip is harder than the knee

Three things make this joint less forgiving. It is deep, so accurate injection requires ultrasound or fluoroscopic guidance rather than landmarks. Its cartilage is thinner than the knee’s and carries higher contact stresses. And it progresses more predictably to end-stage disease than the knee does, so the decisions arrive sooner and with less warning.

That last point deserves emphasis rather than burial. If your hip is bone-on-bone and your life has narrowed around it, the operation is what changes the structure, and an injection series offered as an equivalent would be dishonest. Offered for what it actually does at that stage — buying time, and lowering what it takes to get through a day while you decide — it is a reasonable thing to want, and the timing of the operation is yours rather than ours. See what the operation actually costs.

What is happening in the joint

As in any osteoarthritic joint, the process is active rather than erosive. Synovial inflammation drives IL-1β and TNF-α, matrix metalloproteinases degrade the remaining matrix, subchondral bone remodels and becomes a pain source, and the capsule thickens and restricts. The stiffness people describe on rising from a chair is capsular as much as cartilaginous.

Why some hips deteriorate faster, and how the hip differs from the knee

Structural predisposition explains some of it. Femoroacetabular impingement and acetabular dysplasia both load cartilage abnormally for decades before symptoms appear, and both are worth identifying because they change what should be done.

Beyond structure the drivers are systemic, and the hip has its own numbers rather than the knee’s. In a prospective cohort of 256,364 people followed a median of eleven years, cardiovascular-kidney-metabolic disease at stage 4 carried a hazard ratio of 1.76 (95% CI 1.58 to 1.95) for developing hip osteoarthritis. In participants who also carried high genetic risk it reached 3.10.

Compare that with the knee, where the same study found a hazard ratio of 2.67 rising to 4.00. The metabolic signal is real at the hip and it is smaller than at the knee, and we would rather tell you that than quote you a knee number for a hip problem. The sex split runs the other way too: hip risk was greater in men, knee risk greater in women. It is one more reason the two joints get separate pages here rather than one page about arthritis.

A related caution about transferring evidence: the meta-analysis linking hypertension to osteoarthritis found the association at the knee and did not establish it the same way at the hip. Cited honestly, that is a knee finding. It appears on the knee page for that reason and not on this one.

The mechanism, where it does apply, is the familiar one: adipose-derived inflammatory signaling reaches the synovium through the circulation regardless of mechanical load, and insulin resistance degrades chondrocyte function while glycation stiffens collagen. The panel we run is on the metabolic health page.

The social driver here is mobility itself, and at the hip it is the dominant one. Hip pain reduces walking; reduced walking worsens metabolic health and weakens the abductors that stabilize the joint; both feed back into the pain. It is a descending spiral with several entry points, and an injection addresses exactly one of them. That is the argument for the abductor work described below rather than an argument against treatment.

What PRP can and cannot do here

It will not restore cartilage. What it may do is alter the intra-articular environment enough to reduce pain and improve function for a period — months rather than years, in most reports.

The hip literature is considerably thinner than the knee’s and less consistent. The hip literature is thinner than the knee’s and the trials that exist rarely characterize the preparation or record the metabolic state of the person receiving it, which is most of why they disagree with each other. Nobody should present hip PRP as well-established, and the reasonable framing is that it is a considered option for someone not ready for arthroplasty — aimed at function in earlier disease and at time and medication burden in advanced disease — offered with a clear statement of what the evidence does and does not support.

What else causes pain around the hip

• Greater trochanteric pain syndrome — lateral pain, tender to lie on, gluteal tendon rather than joint
• Labral tear and impingement — catching, clicking, groin pain in a younger patient
• Lumbar referral — L2–L4 pathology referring into the groin and thigh with a normal hip examination
• Sacroiliac joint pain — buttock rather than groin
• Femoral head osteonecrosis — disproportionate pain with relatively preserved joint space, and a reason for prompt imaging rather than injection

What has to line up before we treat a hip

The hip is unusual in that the first question is not whether you are a candidate. It is whether the joint is the problem at all — and as the differential above shows, often it is not. Assume that has been settled: groin pain rather than lateral pain, restricted internal rotation on examination, radiographic change that matches what the examination found. Three things then decide.

How much joint space is left. Preserved or moderately narrowed space is treatable. Advanced loss with deformity is not, and the hip is the joint where replacement results are most reliably good. Where a replacement is what you want, it is the operation that restores the structure. What we will do first is confirm the hip is actually the source, because a substantial share of pain around a hip is not the joint — and going into that consultation with the generator identified is worth more than going in with a scan.

Where you are in the timeline. Most people treated here are too young for a replacement to be a sound lifetime decision, or have a medical reason to defer one. That is the situation this treatment exists to address in the hip, and it is a legitimate place to stand.

Whether the muscle around it will be addressed. A hip injected and then left to the same weak abductors returns to the same mechanics. The section below on why the abductors matter is not an afterthought to the injection; it is the half of the treatment that lasts.

Three things rule it out. Suspected osteonecrosis needs an MRI and a different workup, not an injection into a joint whose bone is failing. Lateral hip pain is usually tendon, and is treated as gluteal tendinopathy rather than as arthritis. And imaging that has not been read against a physical examination is not a diagnosis — it is a picture of a hip that belongs to somebody your age.

How the injection is done

Image-guided, always. A blind hip injection is unreliable and there is no defensible reason to attempt one. Fluoroscopy or ultrasound places the needle intra-articularly; contrast or direct visualization confirms it before the preparation goes in.

Some soreness for a few days is normal, and a hip flare can be more limiting than a knee flare simply because you cannot easily offload it. Plan for two or three quiet days.

The work that follows

• Weeks 0–2 Walking as tolerated, no loaded end-range flexion or rotation.
• Weeks 2–8 Abductor strengthening — gluteus medius and minimus — which reduces joint contact force and is one of the few things that reliably changes hip symptoms.
• Weeks 8–16 Progressive loading, hip hinge mechanics, and gait retraining where a compensatory pattern has developed.
• Ongoing Weight and glycemic management, because both act on the cartilage environment rather than the symptom.

What a hip replacement actually costs

The hip is the joint where replacement results are genuinely good, and nothing below is an argument for avoiding one. It is an argument for knowing the ledger before you pick a date.

What is counted	Reported figure
Any in-hospital complication	27.3%
— of which postoperative anemia	25.2%
Still taking opioids at 12 months	16%
Dislocation within 2 years	3.5%
Venous thromboembolism at 30 days	0.6%
Death within 30 days	0.06–0.23%
Lifetime revision risk if replaced at age 46–50	27.6%
Implant surviving at 10 years	~94%

The headline number needs its caveat stated rather than buried: 27.3% is a broad in-hospital definition and postoperative anemia accounts for most of it. Serious complications are genuinely uncommon. But “complications are rare” and “the total burden is small” are different claims, and only the first one is true.

The number that changes decisions is the last one. A hip replaced in your forties carries a 27.6% lifetime risk of revision — higher than the knee at the same age. That is what sits underneath being told you are too young, and it is a real constraint rather than a brush-off. It is also a reason to own the timing rather than hand it over. The full comparison.

What we tell people honestly

If you are deferring a hip replacement out of fear rather than for a clinical reason, that is worth examining directly. Fear of an operation is a reason to talk the operation through, not a reason to buy injections instead, and the practice does not benefit from keeping you in a chair. What the fear should be weighed against is the actual ledger rather than the brochure — the recovery measured in months, the one-in-four lifetime revision risk for a hip replaced in your forties, the quarter of patients still in pain a year on. Those numbers argue for making the decision deliberately. They do not argue for making it never, and they do not argue for making it now.

Where PRP fits is earlier, and in a narrower window than the marketing around it suggests.

Why the abductors matter more than people expect

The gluteus medius and minimus hold the pelvis level when you stand on one leg, which is what walking is. When they weaken, the pelvis drops on the swing side and the body compensates by leaning over the stance hip — the Trendelenburg pattern. That lean increases the compressive force through the joint you are trying to protect.

So abductor weakness is not a consequence of hip arthritis that can be dealt with later. It is a mechanism by which hip arthritis accelerates itself, and it is one of the few modifiable inputs available. A hip that has been painful for two years has almost always lost abductor capacity, and restoring it changes joint loading in a way no injection does.

This is the practical reason the rehabilitation is not optional here. The injection may reduce pain enough to make the strengthening possible; the strengthening is what alters the trajectory. Reversing that order — injection as the treatment, exercise as the afterthought — produces a good six weeks and an unchanged hip.

Where this sits against pain medication

Hip pain is one of the more common routes onto long-term opioids, because it hurts at rest and at night and because people wait years for surgery they have been told they are too young for. The stewardship position is not to withhold anything from someone in that position. It is to notice that immobility is doing as much damage as the pain — muscle loss, glycemic drift, sleep disruption, isolation — and to aim treatment at restoring movement rather than only at covering the sensation.

What people ask before treating a hip

Is PRP as effective in the hip as the knee?

No. The evidence is thinner and less consistent, and we say so. PRP for knee osteoarthritis.

My pain is on the outside of my hip. Is this the right page?

Probably not — that is usually gluteal tendinopathy. Gluteal tendinopathy.

Will this let me avoid a hip replacement?

It may defer one in earlier disease. It does not replace one in advanced disease. PRP compared with surgery.

Does it have to be image-guided?

Yes. The hip is too deep for reliable landmark injection. What to expect.

Related reading

• Hip, SI joint or lumbar spine?
• Spine and the sacroiliac joint
• Gluteal tendinopathy
• PRP for knee osteoarthritis
• PRP compared with surgery
• Am I a candidate?