What to expect after a joint procedure

What soreness to expect from collection

PRP starts when staff draw blood and spin it to gather more platelets. Those small blood parts help clotting, and the concentrated blood goes into the joint by needle.

For marrow, staff use a needle to draw soft tissue from inside the pelvis. The pelvis and treated joint may both ache, making sitting or sleep harder.

When to call about swelling or redness

Ask the office to write down how much swelling and redness are expected. The note should say when growing warmth, leaking fluid or pain needs a call.

Tell the office about blood thinners, easy bleeding and past procedure trouble. Don't stop prescribed medicine unless the clinician who manages it agrees.

When to get urgent medical care

A hot, swollen joint with fever may mean an infection. Chills, leaking fluid or feeling very ill also need prompt medical care.

New weakness, numbness or lost bladder or bowel control can't wait. Get urgent help, especially when these changes come with back soreness.

What to get in writing before leaving

The note should cover walking, driving, bathing and safe sleep positions. It should also explain what to do when the office is closed.

Read the note while staff can still answer questions. Ask where any bandage belongs and when it may come off.

Sources

1. FDA states verbatim of stem cell products, stromal vascular fraction (adipose-derived cells), umbilical cord blood, Wharton's jelly, amniotic fluid and exosome products: 'None of these products have been approved for the treatment of any orthopedic condition, such as osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain, or shoulder pain.' The only FDA-approved stem cell products in the United States are blood-forming (hematopoietic progenitor) cells derived from umbilical cord blood, approved only for disorders of blood production, and there are currently NO FDA-approved exosome products.

   U.S. Food and Drug Administration — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. FDA (Center for Biologics Evaluation and Research), 2020.

2. FDA's patient and consumer notice on regenerative medicine states that it has received reports of BLINDNESS, TUMOUR FORMATION, neurological events, bacterial infections including life-threatening blood infections, unwanted immune reactions, and cells migrating and forming unintended tissue, following the use of unapproved regenerative medicine products - a list that explicitly includes stromal vascular fraction, amniotic fluid, Wharton's jelly, ortho-biologics and exosomes. It also warns that a product's presence on clinicaltrials.gov, or a firm's registration with FDA, does NOT mean the product is legally marketed.

   U.S. Food and Drug Administration — Important Patient and Consumer Information About Regenerative Medicine Therapies. FDA (Center for Biologics Evaluation and Research), 2021.

3. A systematic review of 32 studies comparing leukocyte-poor and leukocyte-rich PRP in knee OA found both formulations improved pain and function above the MCID with no significant difference between them at 3, 6 or 12 months - but leukocyte-RICH PRP carried significantly higher odds of post-injection pain (OR 1.64; 95% CI 1.29-2.10) and swelling (OR 1.56; 95% CI 1.22-1.99).

   Kim JH, et al. — Adverse Reactions and Clinical Outcomes for Leukocyte-Poor Versus Leukocyte-Rich Platelet-Rich Plasma in Knee Osteoarthritis: A Systematic Review and Meta-analysis.. Orthopaedic Journal of Sports Medicine, 2021. DOI: 10.1177/23259671211011948.

4. A double-blind randomized trial allocated 192 patients with KL 1-3 knee OA to three weekly injections of leukocyte-RICH or leukocyte-POOR PRP (mean leukocyte concentration 7,991 x10^6/L vs 0.1 x10^6/L). No difference was found in any clinical score at 2, 6 or 12 months (IKDC improved 45.6 to 60.7 vs 46.8 to 62.9; P=.626). Mild adverse events were numerically more frequent with leukocyte-rich PRP (12.2% vs 4.7%) but not significantly so.

   Di Martino A, et al. — Leukocyte-Rich versus Leukocyte-Poor Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Double-Blind Randomized Trial.. American Journal of Sports Medicine, 2022. DOI: 10.1177/03635465211064303.

5. A meta-analysis of 6 RCTs (860 patients, 334 receiving BMAC) found overall complication rates of 41.91% for BMAC versus 41.25% for comparator injectables (P=0.85), with knee effusion the commonest BMAC complication at 18.26%. Early and late complication rates did not differ significantly from HA, steroids, PRP, SVF, MSC or saline. The number needed to harm for BMAC relative to other injections was 152.

   Fucaloro S, et al. — Complication rates of bone marrow aspirate concentrate injections versus other injectable therapies for knee osteoarthritis: A systematic review and meta-analysis.. Journal of Orthopaedics, 2025. DOI: 10.1016/j.jor.2024.10.005.

6. The BMJ meta-analysis of viscosupplementation pooled 169 trials (21,163 participants) and found clear evidence of small-study effects and publication bias. In the prespecified main analysis of 24 LARGE placebo-controlled trials (8,997 participants) hyaluronic acid reduced pain by SMD -0.08 (95% CI -0.15 to -0.02), equivalent to 2.0 mm on a 100 mm scale - far below the -0.37 minimal important difference - and trial sequential analysis showed there has been CONCLUSIVE evidence of clinical equivalence to placebo since 2009. Fifteen large trials showed a significantly higher risk of serious adverse events (RR 1.49).

   Pereira TV, et al. — Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis.. BMJ, 2022. DOI: 10.1136/bmj-2022-069722.

7. The 2025 Cochrane review of stem cell injections for knee osteoarthritis pooled 25 randomised trials (1,341 participants) and found that, compared with placebo injection, stem cell injection MAY slightly improve pain (1.2 points better on a 0-10 scale, 7 studies, 445 participants) and function (14.2 points better on a 0-100 scale, 7 studies, 432 participants) up to six months - both rated LOW-certainty evidence, downgraded for indirectness (cell source, preparation and dose varied across studies) and suspected publication bias, since up to three larger RCTs were conducted and withdrawn before reporting results. Radiographic progression was not assessed in any included study.

   Whittle SL, et al. — Stem cell injections for osteoarthritis of the knee.. Cochrane Database of Systematic Reviews, 2025. DOI: 10.1002/14651858.CD013342.pub2.

8. A 2026 systematic review of leukocyte-rich versus leukocyte-poor PRP for osteoarthritis concluded the current evidence is insufficient to determine whether adding leukocytes provides any clinical benefit, that results generally show no significant difference between the two, and that there is no conclusive evidence local reactions are caused by leukocytes specifically.

   Martin-Vega M, et al. — Leukocyte-rich versus leukocyte-poor platelet-rich plasma for Osteoarthritis: A systematic review.. Regenerative Therapy, 2026. DOI: 10.1016/j.reth.2026.101078.

9. A multicenter prospective crossover randomized trial randomised 40 patients with discogenic chronic low back pain to a saline trigger-point control, intradiscal PRP, or intradiscal bone marrow concentrate, with crossover permitted for non-responders. Both PRP and BMC produced statistically significant improvement in pain and function with no adverse events, hospitalisations or surgery at 12 months - but ALL placebo patients reported under 50% relief and crossed over, and the trial was small and open-label.

   Navani A, et al. — The Safety and Effectiveness of Orthobiologic Injections for Discogenic Chronic Low Back Pain: A Multicenter Prospective, Crossover, Randomized Controlled Trial with 12 Months Follow-up.. Pain Physician, 2024.