“Bone on bone” describes a finding on an image. It does not, by itself, tell us how much pain you have, where all of that pain comes from, or when you should have surgery.
At the same time, an injection should not be presented as a reliable way to rebuild a severely arthritic hip. Some people can continue with nonsurgical care. Others have persistent pain, substantial loss of motion, and disability for which replacement becomes the more realistic option.
We see people who want to understand that distinction before making a decision. They may be worried about recovery, caring for a spouse, returning to work, or continuing an active life. My role is to examine the problem and explain what each option can reasonably offer.
What does “bone-on-bone hip” actually mean?
The hip is a ball-and-socket joint. Cartilage covers the joint surfaces and helps them move smoothly. On an X-ray, marked narrowing or loss of the joint space can indicate substantial cartilage loss. Associated findings may include bone spurs, changes in the bone beneath the cartilage, and deformity.
Hip osteoarthritis can cause groin pain, stiffness, reduced motion, and difficulty walking or putting on shoes. The severity of the symptoms and their effect on daily life matter alongside imaging. The AAOS hip-osteoarthritis guideline addresses both nonsurgical care and replacement for symptomatic disease. (1)
It is also possible to have more than one pain source. The lumbar spine, sacroiliac region, gluteal tendons, and tissues around the hip can contribute to symptoms. For the diagnostic discussion, see Before Hip Replacement: Is Your Pain Really Coming from the Hip Joint?
Why patients ask for another option
The concerns we hear include:
- “I want to know whether I can return to the activities I enjoy.”
- “I run a business and am concerned about recovery time.”
- “My other hip was replaced, and I do not want to go through that again.”
- “I am caring for someone and need to understand my choices.”
These concerns deserve a thoughtful discussion. They are reasons to clarify the decision, rather than evidence that an injection will succeed.
The original article emphasized patient education and decision aids. Research has evaluated decision aids for people considering hip or knee arthroplasty. The goal should be an informed choice aligned with the patient’s needs and preferences. Declining surgery is not, on its own, evidence of a better health outcome. (2)
Can useful hip motion predict whether stem cell treatment will work?
I pay attention to range of motion, walking ability, the location of tenderness, and the movements that reproduce pain. Remaining motion and function help frame the discussion. They do not constitute a validated test showing that bone marrow injections will work.
Someone who ran a marathon last year may still have a serious new hip problem. Someone who is stiff or inactive may have several treatable contributors to pain. Neither activity level nor an X-ray label should become a promise of success.
A more useful question is: What is limiting this person now, and what evidence supports treating that particular problem?
What nonsurgical treatments are supported by guidelines?
Depending on disease severity and individual health, care may include appropriately adapted exercise, physical therapy, a walking aid, weight management when relevant, and medication after reviewing its risks. AAOS supports oral anti-inflammatory medication when appropriate and physical therapy for mild-to-moderate symptomatic hip arthritis. Corticosteroid injections may provide short-term relief; hyaluronic acid injections are not recommended for hip arthritis because they have not performed better than placebo. (1)
These options can help symptoms without restoring normal joint anatomy. They also should not become an endless sequence of treatments when the hip joint is clearly responsible for major, persistent disability.
When should hip replacement remain a serious consideration?
Replacement deserves consideration when advanced joint disease is consistent with the symptoms, pain and loss of function remain substantial, and appropriate nonsurgical care has been ineffective. The decision includes medical risks, expected recovery, goals, and what continuing to wait is likely to mean.
The 2023 ACR/AAHKS timing guideline addresses patients with symptomatic and radiographic moderate-to-severe osteoarthritis or advanced osteonecrosis who have already tried ineffective nonsurgical treatment and chosen replacement. For that population, it conditionally recommends proceeding without delaying surgery solely to try additional physical therapy, medication, walking aids, or injections. These recommendations were based on low- or very-low-quality evidence and require individual judgment. (3)
This does not mean every person with joint-space loss needs immediate surgery. It means that someone who has reached an appropriate surgical decision should not be told that another biologic injection is a necessary step.
What is bone marrow concentrate, and what might it do?
Bone marrow aspirate concentrate—BMAC or BMC—is a preparation from the patient’s bone marrow containing a mixture of cells and signaling components, including a small population of progenitor cells. It is often described as “stem cell therapy,” but it is not a purified or culture-expanded stem-cell product.
Researchers are studying whether these preparations can influence inflammation and the local tissue environment. Possible symptom improvement is a different claim from rebuilding lost cartilage, restoring the shape of the femoral head, or reliably preventing replacement.
Our published hip study: four patient experiences
In a 2018 case series, our research team reported short-term outcomes in four patients with hip osteoarthritis who received four bone marrow concentrate injections. I want to preserve these individual accounts because they show the patients’ starting problems and reported changes. The series had no comparison group and cannot establish a success rate, cartilage regeneration, or lasting avoidance of replacement. (4)
Case 1: A 75-year-old woman with severe arthritis
She had a 10-year history of worsening right-hip pain. Two surgeons had recommended replacement, and MRI showed severe osteoarthritis with extensive bone spurs and near-complete loss of joint space. Sitting for a long time was particularly painful; resting and active pain were both 6/10.
She received four treatments over 49 days. After the second, she reported 40% improvement and greater flexibility. After the fourth, she reported 60% overall improvement, resting and active pain of 2/10, and a functionality score of 37/40. She also reported better sleep and had not undergone replacement at the final short-term follow-up.
Case 2: A 61-year-old man with pain during standing and exercise
He had two years of hip pain and severe arthritis on radiographs. Chiropractic care, cupping, and physical therapy had provided only brief relief. Baseline pain was 1/10 at rest and 7/10 with activity; his functionality score was 28/40.
He received four treatments over 42 days. After the first, he reported 80% overall improvement. At follow-up after the fourth, he reported pain of 0/10 at rest and 2/10 with activity, a functionality score of 37/40, and 94% overall improvement. He had resumed exercise.
Case 3: A 76-year-old man who had already undergone replacement on the other side
He had seven years of right-hip pain and moderate-to-severe osteoarthritis on MRI. Recovery from a previous left-hip replacement had been difficult, and he hoped to avoid another operation. Baseline resting pain was 4/10, active pain 5/10, and his functionality score 33/40.
He received four treatments over 54 days. After the second, he reported 50% improvement with greater flexibility. After the fourth, he reported 65% overall improvement, resting pain of 1/10, active pain of 2/10, and a functionality score of 37/40. He reported walking longer distances without pain.
Case 4: A 56-year-old contractor with mild arthritis
He had two years of worsening hip pain that interfered with his physically demanding work. An epidural injection had not helped. His radiograph showed mild arthritis, so this case should not be described as bone-on-bone disease. Baseline resting pain was 2/10, active pain 5/10, and his functionality score 17/40.
He received four treatments over 146 days. Improvement was incremental during the first three. Forty days after the fourth, he reported 70% overall improvement, resting and active pain of 1/10, and a functionality score of 30/40.
What these cases establish is that four people reported short-term improvement. They do not show that the injections repaired cartilage or that the same result should be expected in another person. Avoiding surgery during a brief observation period is not proof of avoiding it permanently.
What does newer hip research add?
Small clinical studies suggest possible symptom benefit
A separate 2018 cohort included 19 patients with early hip or knee osteoarthritis and reported satisfactory results in 63.2%. Two patients proceeded to hip replacement within eight months. Because the study combined joints, lacked a control group, and concerned early arthritis, it cannot establish the likelihood of success in a bone-on-bone hip. (5)
A 2024 systematic review of hip BMAC research included five studies and 182 patients. The studies reported improvements in pain and function, but the review called for stronger controlled studies and longer follow-up. The absence of reported adverse events in small studies cannot establish that a procedure is risk-free. (6)
A 2026 long-term study is promising, but used an injection into bone
A matched cohort study followed 434 hips for up to 15 years. Replacement occurred in 35 of 217 hips receiving intraosseous BMC and 87 of 217 controls. The treatment was delivered into the femoral head under imaging guidance, rather than simply into the joint space. (7)
This is an encouraging association, especially for further study before advanced disease. However, it was not randomized; selection, treatment decisions, and other differences may influence who undergoes replacement. The authors disclosed relationships with Regenexx. Remaining free of replacement also does not prove cartilage regrowth or freedom from pain. The findings cannot be assumed to apply to another injection technique or a severely deformed hip.
What about PRP for a bone-on-bone hip?
Platelet-rich plasma is prepared from blood and contains concentrated platelets. It is biologically different from bone marrow concentrate. The hip evidence is mixed, and research from knee arthritis cannot establish benefit in an advanced hip.
In a 2024 double-blind trial, 60 patients with grade 2 or 3 hip arthritis received three weekly ultrasound-guided PRP or saline injections. PRP did not provide a significant advantage over saline in pain, function, or quality of life during six months of follow-up. The study did not establish effectiveness in end-stage disease. (8)
A September 2026 review of PRP and BMAC across hip disorders found heterogeneous evidence and no randomized head-to-head comparison establishing one as superior. It noted that standalone intra-articular BMAC evidence for hip arthritis remained based on small uncontrolled cohorts. This differs from research on marrow used within bone or during hip-preservation surgery. (9)
The 2019 ACR/Arthritis Foundation guideline, published in 2020, strongly recommended against PRP and stem-cell injections for hip osteoarthritis, citing problems with standardization and heterogeneous preparations. (10) The May 2026 VA/DOD guideline judged evidence insufficient to recommend for or against PRP for hip arthritis. Neither position supports promising cartilage restoration. (11)
Osteonecrosis is a different diagnosis from osteoarthritis
Osteonecrosis, or avascular necrosis, involves damage to bone associated with loss of its blood supply. The femoral head may eventually collapse. Treatment depends on the stage and extent of involvement.
The Toronto review cited in the earlier version of this article concerned early-stage osteonecrosis. It should not be presented as proof that an injection into a bone-on-bone arthritic hip regrows cartilage. (12)
Likewise, the frequently cited study of 189 hips in 116 patients involved core decompression with autologous bone marrow grafting for osteonecrosis. That is a procedure directed into bone, rather than evidence for a routine intra-articular injection treating advanced osteoarthritis. (13)
In selected precollapse cases, a hip-preservation surgeon may discuss decompression and biological augmentation. Once collapse and secondary arthritis are advanced, an injection should not be assumed to restore the femoral head’s shape. A recommendation based on osteonecrosis research must specify the disease stage and procedure studied.
Wharton’s jelly: early hip-specific research
Wharton’s jelly is connective tissue within the umbilical cord. Tissue allografts, isolated donor cells, expanded cells, and exosome preparations are different products and should not be treated as interchangeable.
A 2024 retrospective report evaluated 69 patients receiving a cryopreserved cord-tissue allograft for hip osteoarthritis. Patient-reported pain measures improved over short follow-up. The study came from a manufacturer-associated observational repository and had no randomized comparison group. Its findings justify further investigation, but do not establish cartilage replacement, lasting benefit, or avoidance of surgery in bone-on-bone arthritis. (14)
The product name and the study title should not be interpreted as proof that the material physically replaced missing cartilage or supplied living stem cells that regenerated the joint.
Exosomes: promising orthopedic biology, without established benefit for advanced hip arthritis
Exosomes are small extracellular vesicles involved in cell communication. Researchers are investigating their effects on inflammation and tissue repair.
A 2025 rat study found favorable repair characteristics after Wharton’s jelly-cell-derived exosome treatment of surgically created knee cartilage defects. This was a short-term experiment in a focal defect, rather than a trial in people with advanced hip arthritis. (15)
Clinical translation remains uncertain. A 2024 placebo-controlled trial of placental-cell-derived extracellular vesicles in knee osteoarthritis found no significant advantage in symptoms or MRI findings through six months. That trial used a different preparation and joint, so it cannot settle the hip question; it demonstrates why laboratory promise requires clinical confirmation. (16)
The FDA states that there are no FDA-approved exosome products and that the regenerative products discussed in its consumer alert, including Wharton’s jelly products, are not approved for orthopedic conditions. These research findings do not establish that any particular donor-cell or exosome preparation is offered by Dr. Darrow. (17)
How should an injection and hip replacement be compared?
I would compare them in terms of the actual diagnosis, symptom severity, remaining function, prior treatment, likely benefit, risks, and uncertainty. An injection carries risks such as infection, bleeding, and a pain flare; bone marrow collection adds its own discomfort and procedural risks. Replacement has a different risk and recovery profile that deserves a surgical discussion.
If symptoms are manageable and function remains useful, continued nonsurgical care may fit the patient’s goals. If pain is severe, walking is progressively restricted, or joint destruction is advanced, repeatedly pursuing injections may postpone more appropriate treatment. Sudden inability to bear weight, acute severe pain, fever, or a rapidly worsening condition needs prompt assessment.
The question is not simply whether you can postpone an operation. It is whether the next treatment offers a realistic chance of better function and quality of life.
References
3 Hannon CP, Goodman SM, Austin MS, et al. 2023 American College of Rheumatology and American Association of Hip and Knee Surgeons Clinical Practice Guideline for the Optimal Timing of Elective Hip or Knee Arthroplasty for Patients With Symptomatic Moderate-to-Severe Osteoarthritis or Advanced Symptomatic Osteonecrosis With Secondary Arthritis for Whom Nonoperative Therapy Is Ineffective. Arthritis & Rheumatology. 2023;75(11):1877–1888. doi:10.1002/art.42630.
4 Darrow M, Shaw B, Darrow B, Wisz S. Short-Term Outcomes of Treatment of Hip Osteoarthritis With 4 Bone Marrow Concentrate Injections: A Case Series. Clinical Medicine Insights: Case Reports. 2018;11:1179547618791574. doi:10.1177/1179547618791574.
5 Rodriguez-Fontan F, Piuzzi NS, Kraeutler MJ, Pascual-Garrido C. Early Clinical Outcomes of Intra-Articular Injections of Bone Marrow Aspirate Concentrate for the Treatment of Early Osteoarthritis of the Hip and Knee: A Cohort Study. PM&R. 2018;10(12):1353–1359. doi:10.1016/j.pmrj.2018.05.016.
6 Chandrashekar S, Jeyaraman M, Mounissamy P, Jeyaraman N, Khanna M. Safety and Efficacy of Bone-Marrow Aspirate Concentrate in Hip Osteoarthritis: A Systematic Review of Current Clinical Evidence. Indian Journal of Orthopaedics. 2024;58(7):835–844. doi:10.1007/s43465-024-01183-7.
7 Hernigou P, Centeno CJ, Berger DR, Dodson E, Murphy MB. Intraosseous bone marrow concentrate delays total hip arthroplasty in osteoarthritis: A fifteen year matched cohort study with dose-response analysis. International Orthopaedics. 2026;50(7):1617–1626. doi:10.1007/s00264-026-06908-x.
8 Topaloglu M, Şen Eİ, Sarıkaya D, Dıraçoğlu D. Effect of platelet-rich plasma injections versus placebo on pain and quality of life in patients with hip osteoarthritis: A double-blind, randomized clinical trial. Turkish Journal of Physical Medicine and Rehabilitation. 2024;70(2):212–220. doi:10.5606/tftrd.2024.13855.
9 Jeon SY, Jung CH, Choi SY, Lee DH. Platelet-Rich Plasma Versus Bone Marrow Aspirate Concentrate for Hip Disorders: A Narrative Review of Biological Rationale, Clinical Evidence, and Research Priorities. Bioengineering. 2026;13(9):1018. doi:10.3390/bioengineering13091018.
10 Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee. Arthritis Care & Research. 2020;72(2):149–162. doi:10.1002/acr.24131.
11 Department of Veterans Affairs; Department of Defense. VA/DOD Clinical Practice Guideline for the Non-Surgical Management of Hip & Knee Osteoarthritis. Version 3.0. May 2026. Evidence reviewed through July 31, 2025.
12 Lau RL, Perruccio AV, Evans HMK, Mahomed SR, Mahomed NN, Gandhi R. Stem cell therapy for the treatment of early stage avascular necrosis of the femoral head: a systematic review. BMC Musculoskeletal Disorders. 2014;15:156. doi:10.1186/1471-2474-15-156.
13 Hernigou P, Beaujean F. Treatment of osteonecrosis with autologous bone marrow grafting. Clinical Orthopaedics and Related Research. 2002;(405):14–23. doi:10.1097/00003086-200212000-00003.
14 Lai A, Tamea C, Shou J, et al. Retrospective Evaluation of Cryopreserved Human Umbilical Cord Tissue Allografts in the Supplementation of Cartilage Defects Associated with Hip Osteoarthritis. Journal of Clinical Medicine. 2024;13(14):4040. doi:10.3390/jcm13144040.
15 Meriç G, Eren O, Yaba A, Aksu BÇ, Başdelioğlu K, Ateş U. Comparative analysis of the therapeutic effects of mesenchymal stem cells and exosomes on cartilage regeneration: exploring their synergistic potential with hyaluronic acid for treating articular cartilage defects. European Journal of Orthopaedic Surgery & Traumatology. 2025;35:154. doi:10.1007/s00590-025-04284-7.
16 Bolandnazar NS, Raeissadat SA, Haghighatkhah H, et al. Safety and efficacy of placental mesenchymal stromal cells-derived extracellular vesicles in knee osteoarthritis: a randomized, triple-blind, placebo-controlled clinical trial. BMC Musculoskeletal Disorders. 2024;25:856. doi:10.1186/s12891-024-07979-w.
17 U.S. Food and Drug Administration. Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. July 22, 2020. Accessed November 11, 2026.
