# What do fair studies say about each choice? *What We Know About Knee Care — Knee Pain Treatment Glendale* > What is known and still unsure when knee pain treatment Glendale includes cortisone, gel, PRP, or marrow concentrate. ## Which claims deserve a second look? Glendale trails can make a knee ache most on the downhill stretch. The sore part of the walk matters when you compare your knee with people in a study. A fair test compares a treatment with salt water or another choice. It’ll also check whether people could walk, use stairs, or sleep better afterward. Some people improve after cortisone, gel, or platelet-rich plasma, called PRP. For PRP, blood from the arm is spun, and the platelet-heavy part goes into the knee. I’d want both the good and bad findings before paying. No honest study can tell you exactly what your knee will do. ## What did the better studies find? Cortisone can ease soreness for a few weeks, but the effect often fades. Regular repeats can harm cartilage without giving better long-term relief. In large fair studies, gel beat salt water by about 2 points on a 100-point soreness line. Most people wouldn’t notice a change that small. The largest strong PRP test found no better soreness relief than salt water at 12 months. Other studies found better walking and stair use with PRP than with gel. Both findings are real, which is why certainty would be false. PRP made with different platelet amounts or white blood cell amounts may also give different results. ## How can I tell whether care helped me? Bone marrow concentrate is liquid marrow drawn from the pelvis, with a smaller portion separated out for the knee. It hasn’t been shown to work better than PRP, and much less research has been done. Here’s what the uncertainty means for you: nobody can name your result beforehand. An exam can’t promise an outcome, though it can show whether a choice is worth discussing. Choose one ordinary task and write down your limit before treatment. Check the same walk, stairs, or sleep again later, including on a harder day. Keep doing the strength work and light movement that help. QC Kinetix offers regenerative treatments, its name for clinic choices made with a sample of your own blood or liquid marrow; after checking the knee, its medical providers—the people who examine you and carry out care—can explain the non-surgical choices and their limits, but the name doesn’t settle whether you’ll improve. ## Sources 1. The RESTORE trial randomized 288 adults aged 50+ with symptomatic mild-to-moderate medial knee OA to three weekly leukocyte-poor PRP injections or saline placebo. At 12 months, pain change was -2.1 vs -1.8 points (difference -0.4; 95% CI -0.9 to 0.2; P=.17) and medial tibial cartilage volume change was -1.4% vs -1.2% (P=.81). 29 of 31 prespecified secondary outcomes showed no significant between-group difference. The authors concluded the findings 'do not support use of PRP for the management of knee OA.' Bennell KL, Paterson KL, Metcalf BR, et al. — [Effect of Intra-articular Platelet-Rich Plasma vs Placebo Injection on Pain and Medial Tibial Cartilage Volume in Patients With Knee Osteoarthritis: The RESTORE Randomized Clinical Trial.](https://pubmed.ncbi.nlm.nih.gov/34812863/). *JAMA*, 2021. DOI: 10.1001/jama.2021.19415. 2. A 2026 network meta-analysis of 21 RCTs (2,254 patients) found both leukocyte-poor and leukocyte-rich PRP significantly improved 6-12 month WOMAC function versus placebo (MD -10.54 and -13.20 respectively) and both were superior to hyaluronic acid, with leukocyte-poor PRP ranked first (P-score 0.96) — a materially more favourable read of PRP than the RESTORE trial, which is why this corpus presents both. Journal of Orthopaedic Surgery and Research authors — [Leukocyte-rich versus leukocyte-poor platelet-rich plasma and hyaluronic acid for knee osteoarthritis: a systematic review and network meta-analysis.](https://pubmed.ncbi.nlm.nih.gov/41629990/). *Journal of Orthopaedic Surgery and Research*, 2026. DOI: 10.1186/s13018-026-06689-4. 3. A meta-analysis of 28 RCTs (3,246 knee OA patients) reported PRP gave pain relief comparable to hyaluronic acid with better functional improvement, no significant difference versus corticosteroid as monotherapy, and better pain and function than physical or exercise therapy; the authors also reported better outcomes in KL grade I-II knees, i.e. earlier disease. European Journal of Medical Research authors — [Efficacy and safety of platelet-rich plasma injections for the treatment of knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials.](https://pubmed.ncbi.nlm.nih.gov/41107915/). *European Journal of Medical Research*, 2025. DOI: 10.1186/s40001-025-03253-4. 4. A systematic review and meta-analysis of 32 trials classified PRP by total deliverable platelets and found all dose bands beat hyaluronic acid, with the moderate-dose band (5-10 billion platelets) showing the largest effect (SMD 1.48) and the low (1-5 billion) and high (>10 billion) bands moderate effects (SMD 0.47 and 0.68) — evidence that dose, not brand, drives reported differences. PM&R authors — [Platelet-rich plasma outcomes in knee osteoarthritis are associated with the amount of total deliverable platelets: A systematic review and meta-analysis.](https://pubmed.ncbi.nlm.nih.gov/40980837/). *PM&R*, 2026. DOI: 10.1002/pmrj.13455. 5. A 150-patient randomized trial reported that an absolute count of 10 billion platelets was needed for a PRP formulation to sustain benefit to one year versus hyaluronic acid (WOMAC and IKDC differences p<0.001; +120 m vs +4 m in 6-minute pain-free walking distance). Because clinic PRP systems vary widely in platelet yield, 'PRP' is not one intervention and results are not transferable between preparations. Bansal H, Leon J, Pont JL, et al. — [Platelet-rich plasma (PRP) in osteoarthritis (OA) knee: Correct dose critical for long term clinical efficacy.](https://pubmed.ncbi.nlm.nih.gov/33597586/). *Scientific Reports*, 2021. DOI: 10.1038/s41598-021-83025-2. 6. A double-blind RCT of 192 patients followed to a mean of 64 months found PRP did NOT provide superior clinical improvement over hyaluronic acid on any score at any follow-up point. Median duration of subjective symptomatic relief was 12 months for PRP and 9 months for HA (not significant). The only significant difference was a lower 24-month reintervention rate with PRP (22.6% vs 37.1%, P=.036). Di Martino A, Di Matteo B, Papio T, et al. — [Platelet-Rich Plasma Versus Hyaluronic Acid Injections for the Treatment of Knee Osteoarthritis: Results at 5 Years of a Double-Blind, Randomized Controlled Trial.](https://pubmed.ncbi.nlm.nih.gov/30545242/). *American Journal of Sports Medicine*, 2019. DOI: 10.1177/0363546518814532. 7. In the 12-month randomized trial from the same cohort, both PRP and HA improved IKDC scores significantly from baseline with no significant intergroup difference at any follow-up; PRP caused significantly MORE post-injection swelling and pain. The authors concluded PRP 'should not be preferred to viscosupplementation'. Filardo G, Di Matteo B, Di Martino A, et al. — [Platelet-Rich Plasma Intra-articular Knee Injections Show No Superiority Versus Viscosupplementation: A Randomized Controlled Trial.](https://pubmed.ncbi.nlm.nih.gov/25952818/). *American Journal of Sports Medicine*, 2015. DOI: 10.1177/0363546515582027. 8. A safety review of intra-articular PRP in knee OA found significantly higher rates of mild knee pain and swelling than hyaluronic acid (p<0.001), driven specifically by leukocyte-RICH formulations; leukocyte-poor PRP showed a safety profile similar to HA. No severe adverse events were reported in any group. PM&R authors — [Assessment of adverse events and safety associated with intra-articular platelet-rich plasma injections compared with hyaluronic acid and saline in knee osteoarthritis.](https://pubmed.ncbi.nlm.nih.gov/42101047/). *PM&R*, 2026. DOI: 10.1002/pmrj.70141. 9. FDA states verbatim: '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. 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](https://www.fda.gov/vaccines-blood-biologics/consumers-biologics/consumer-alert-regenerative-medicine-products-including-stem-cells-and-exosomes). *FDA (Center for Biologics Evaluation and Research)*, 2020. ## Want someone to look at your knee? Take notes about the ache, your medicines, and earlier care. The clinician examining your knee can explain the choices and say when other care makes more sense. Schedule a free consultation: --- Straight talk about a sore knee. Straight answers about knee soreness, simple home care, danger signs, treatment choices, and nearby clinics. Plain help for understanding a sore knee and deciding what to ask next. This site is operated by the owners of the QC Kinetix Phoenix-area clinics, including the locations serving Glendale, and those owners benefit when readers book a consultation. © 2026 Glendale Knee Field Notes. General education only; it does not replace diagnosis or advice from a qualified medical professional.