Why does my knee stay sore, and what may help?

Why does my knee hurt after walking or sitting?

Arthritis can leave a knee stiff after rest and sore after use. An old injury may change the way you step. Weak leg muscles can make daily movement harder. A doctor needs to examine the knee before naming the cause.

Mark the exact spot where the ache starts. Also note swelling, catching, or a knee that gives way. I'd take old X-rays or visit notes if they're easy to find. Those details can make the exam more useful.

What happens when someone checks my knee?

The visit starts with walking, stairs, sleep, and the care you've already tried. A doctor examines tender areas, swelling, strength, and how far the knee bends. Old X-rays may help if they show why movement is hard. Ask which exam finding best explains your daily limits.

QC Kinetix offers regenerative treatments, which are non-surgical choices its medical providers give in the clinic after checking your knee and hearing what daily movement now costs you. Medical providers are the trained clinic staff who handle that exam and discuss your choices. PRP, or platelet-rich plasma, is prepared by concentrating platelets from your own blood. The clinic may also discuss concentrated PRP and knee surgery alternatives.

When can't my knee wait for a regular visit?

A hot knee with fever or heavy swelling needs medical care now. Get quick help if the knee changed shape after a fall. The same goes when it can't hold your weight. Calf swelling, redness, or soreness after care also needs a prompt call.

Steady soreness without those signs can usually wait for an office exam. Ask what activity is safe until then. You can also ask how you'll judge whether care helped. Don't pay until the cost and time are clear.

Sources

1. In a 480-patient, four-arm, multicenter randomized phase 2/3 trial, none of three orthobiologic cell injections - autologous bone marrow aspirate concentrate, autologous adipose stromal vascular fraction, or allogeneic umbilical cord tissue-derived mesenchymal stromal cells - was superior to any other, or to a corticosteroid injection control, on pain at 12 months.

   Mautner K, et al. — Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial. Nat Med, 2023. DOI: 10.1038/s41591-023-02632-w.

2. A 2024 systematic review of 8 Level I randomized trials in 937 patients found bone marrow aspirate concentrate improved pain and function versus baseline from one month, but the comparative advantage over other injections was inconsistent across timepoints.

   Han JH, et al. — Bone Marrow Aspirate Concentrate Injections for the Treatment of Knee Osteoarthritis: A Systematic Review of Randomized Controlled Trials. Orthop J Sports Med, 2024. DOI: 10.1177/23259671241296555.

3. In a randomized trial of 118 knee osteoarthritis patients followed for 2 years with serial MRI, a single microfragmented adipose tissue injection and a single PRP injection produced statistically and clinically similar improvement - and the imaging showed no structural advantage for either.

   Zaffagnini S, et al. — Microfragmented Adipose Tissue Versus Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Prospective Randomized Controlled Trial at 2-Year Follow-up. Am J Sports Med, 2022. DOI: 10.1177/03635465221115821.

4. A phase III double-blind placebo-controlled trial in 261 patients with Kellgren-Lawrence grade 3 knee osteoarthritis tested a single injection of autologous culture-expanded adipose-derived mesenchymal stem cells - a product that cannot legally be sold outside a clinical trial in the United States because culture expansion is more than minimal manipulation.

   Kim KI, et al. — Clinical Efficacy and Safety of the Intra-articular Injection of Autologous Adipose-Derived Mesenchymal Stem Cells for Knee Osteoarthritis: A Phase III, Randomized, Double-Blind, Placebo-Controlled Trial. Am J Sports Med, 2023. DOI: 10.1177/03635465231179223.

5. A controlled randomized phase I/II trial in 26 patients found repeated dosing of culture-expanded umbilical cord-derived MSCs at baseline and 6 months produced lower WOMAC pain at 12 months (1.1 +/- 1.3) than hyaluronic acid (4.3 +/- 3.5), while a single MSC dose did not separate from hyaluronic acid.

   Matas J, et al. — Umbilical Cord-Derived Mesenchymal Stromal Cells (MSCs) for Knee Osteoarthritis: Repeated MSC Dosing Is Superior to a Single MSC Dose and to Hyaluronic Acid in a Controlled Randomized Phase I/II Trial. Stem Cells Transl Med, 2019. DOI: 10.1002/sctm.18-0053.

6. A meta-analysis of 14 placebo cohorts across 13 Level I trials in 1,076 knee osteoarthritis patients found that intra-articular saline - the placebo - produced pain and function improvements exceeding the minimal clinically important difference at 3 and 6 months.

   Saltzman BM, et al. — The Therapeutic Effect of Intra-articular Normal Saline Injections for Knee Osteoarthritis: A Meta-analysis of Evidence Level 1 Studies. Am J Sports Med, 2017. DOI: 10.1177/0363546516680607.

7. FDA states in its consumer alert that the only FDA-approved stem cell products in the United States are blood-forming stem cells derived from umbilical cord blood, approved for disorders of the blood-forming system, and that NONE of these products - stem cells, stromal vascular fraction, umbilical cord blood, Wharton's jelly or amniotic fluid - has been approved for the treatment of any orthopedic condition, including osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain or shoulder pain.

   US Food and Drug Administration, Center for Biologics Evaluation and Research — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. , 2020.

8. 21 CFR 1271.10(a) sets the four criteria a human cell or tissue product must meet to be regulated SOLELY under section 361 of the Public Health Service Act: it must be minimally manipulated; intended for homologous use only, as reflected by labeling and advertising; not combined with another article beyond water, crystalloids or a preserving agent; and either have no systemic effect and not depend on the metabolic activity of living cells, or else be for autologous use, use in a close blood relative, or reproductive use.

   US Code of Federal Regulations, Title 21 — 21 CFR 1271.10 - Are my HCT/P's regulated solely under section 361 of the PHS Act. , 2004.

9. A double-blind randomized trial testing whether adding bone marrow aspirate concentrate to arthroscopic partial meniscectomy improves outcomes in patients with early knee osteoarthritis used the IKDC score at one year as its primary endpoint, with Kellgren-Lawrence grade as a radiographic secondary.

   Yanke AB, et al. — A Prospective, Randomized, Double-Blind Clinical Trial to Investigate the Efficacy of Autologous Bone Marrow Aspirate Concentrate During Arthroscopic Meniscectomy in Patients With Early Knee Osteoarthritis. Am J Sports Med, 2024. DOI: 10.1177/03635465241275647.