Knee cartilage repair: which choices may help me?

What can ease soreness without surgery?

Changing how much the joint carries is often a useful first step. Shorten a walk, avoid a deep bend, or divide a heavy job. Exercise builds the muscles that hold the joint steady. It doesn't replace worn cartilage, but stronger muscles may make daily movement easier. Cold can help when activity leaves swelling. A doctor can also review medicine and other ways to ease soreness. Home care isn't enough when the joint is hot, badly swollen, or unable to hold your weight.

A careful exam can show whether the soreness needs more than rest and exercise.

When does surgery enter the discussion?

Surgery may come up when one damaged patch matches the soreness and simpler care hasn't helped. Some operations trim loose tissue. Others form repair tissue or move cartilage and bone into the worn patch. Cartilage restoration may fit a deep, clearly outlined patch with healthier cartilage around it. It usually doesn't fit wear spread across most of the joint. An exam and X-ray help tell those problems apart. Ask how each choice may change walking, recovery time, and later surgery. Until then, keep movement easy enough that swelling doesn't rise by morning.

Before choosing surgery, QC Kinetix offers regenerative options, a name for care without surgery such as PRP: staff take and spin your blood to keep a platelet-rich portion, and a medical provider puts it into the joint as a shot intended to ease soreness.

Sources

1. A JBJS evidence-based review of chondral lesions of the knee sets management by lesion size, location, limb alignment and rotation, and patient demand rather than by product: osteochondral autograft transfer is described as durable and predictable for smaller lesions (under 2 cm2) in young active patients, while lesions of 2 cm2 or more are typically treated with osteochondral allograft transplantation, particulated juvenile articular cartilage, or matrix-associated chondrocyte implantation, with favourable mid- and long-term results reported for allograft or MACI in large lesions of 3 cm2 or more.

   Dekker TJ, et al. — Chondral Lesions of the Knee: An Evidence-Based Approach.. J Bone Joint Surg Am, 2021. DOI: 10.2106/JBJS.20.01161.

2. The Cochrane review of surgical interventions for isolated cartilage defects of the knee in adults found only three randomised trials, all comparing mosaicplasty with microfracture, reporting 133 participants in total with a mean defect area of 2.8 cm2. It found NO randomised trials of allograft transplantation or drilling at all, judged every trial at high or unclear risk of bias, and rated the quality of evidence very low for every outcome.

   Gracitelli GC, et al. — Surgical interventions (microfracture, drilling, mosaicplasty, and allograft transplantation) for treating isolated cartilage defects of the knee in adults.. Cochrane Database Syst Rev, 2016. DOI: 10.1002/14651858.CD010675.pub2.

3. FDA biologics licence BL 125603 (Vericel) describes MACI verbatim as "an autologous cellularized scaffold product indicated for the repair of symptomatic, single or multiple full-thickness cartilage defects of the knee with or without bone involvement in adults." The licensed indication is a two-stage surgical implantation for full-thickness DEFECTS of the knee in adults. It is not an injection, it is not licensed for osteoarthritis, and it is not licensed for any joint other than the knee.

   U.S. Food and Drug Administration — MACI (autologous cultured chondrocytes on porcine collagen membrane). FDA, Center for Biologics Evaluation and Research, 2024.

4. In the RESTORE randomised trial, 288 people aged 50 or over with symptomatic mild-to-moderate medial knee osteoarthritis received three weekly injections of leukocyte-poor PRP or saline placebo. At 12 months there was no significant difference in knee pain (-2.1 versus -1.8 points) and none in medial tibial cartilage VOLUME (-1.4% versus -1.2%). Twenty-nine of 31 prespecified secondary outcomes also showed no difference.

   Bennell KL, 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.. JAMA, 2021. DOI: 10.1001/jama.2021.19415.

5. A four-arm phase 2/3 randomised trial assigned 480 patients with knee osteoarthritis to autologous bone marrow aspirate concentrate, allogeneic umbilical cord tissue mesenchymal stromal cells, autologous adipose stromal vascular fraction or a corticosteroid injection. At one year, no cell injection was superior to another or to the corticosteroid control, and NONE of the four groups showed a significant change in the MRI osteoarthritis score from baseline.

   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.

6. FDA's consumer alert states verbatim of stem cell products, exosome products, adipose-derived stromal vascular fraction, umbilical cord blood, Wharton's Jelly and amniotic fluid 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 stem cell products carrying FDA licensure are blood-forming cells derived from umbilical cord blood, licensed only for disorders of blood production, and there are currently no licensed exosome products.

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

7. Forty-five people who had had a partial medial meniscectomy 3-5 years earlier were randomised to four months of supervised exercise three times weekly or to no intervention. The exercise group improved cartilage glycosaminoglycan content measured by dGEMRIC relative to controls (+15 ms versus -15 ms; P = 0.036), with a strong dose-response to reported activity. Adult cartilage can adapt its composition to loading - which is not the same as filling a hole in it.

   Roos EM, et al. — Positive effects of moderate exercise on glycosaminoglycan content in knee cartilage: a four-month, randomized, controlled trial in patients at risk of osteoarthritis.. Arthritis Rheum, 2005. DOI: 10.1002/art.21415.

8. Among 321 consecutive patients treated with autologous chondrocyte implantation (522 defects), defects previously treated with a marrow stimulation technique failed at 26% versus 8% in defects with no prior penetration of the subchondral bone - a threefold higher failure rate. The order in which procedures are done changes what the later ones can achieve.

   Minas T, et al. — Increased failure rate of autologous chondrocyte implantation after previous treatment with marrow stimulation techniques.. Am J Sports Med, 2009. DOI: 10.1177/0363546508330137.

9. A prospective cohort of 110 patients treated with microfracture for a focal chondral defect was evaluated at a median of 12 years. Scores improved significantly from baseline and did not differ from the 5-year results, but 43 patients had needed further knee surgery including seven knee replacements, 50 had a poor long-term outcome, and normal knee function was generally not achieved. The authors called for caution in recommending microfracture.

   Solheim E, et al. — Results at 10-14 years after microfracture treatment of articular cartilage defects in the knee.. Knee Surg Sports Traumatol Arthrosc, 2016. DOI: 10.1007/s00167-014-3443-1.

10. At 14 to 15 years, the Norwegian multicentre randomised trial of 80 patients with a single symptomatic femoral condyle cartilage defect found no significant difference between autologous chondrocyte implantation and microfracture on any clinical scoring system. There were 17 failures in the ACI group versus 13 after microfracture, and more total knee replacements had been needed after ACI (6 versus 3).

    Knutsen G, et al. — A Randomized Multicenter Trial Comparing Autologous Chondrocyte Implantation with Microfracture: Long-Term Follow-up at 14 to 15 Years.. J Bone Joint Surg Am, 2016. DOI: 10.2106/JBJS.15.01208.