Living with Knee Pain and When to Consider Regenerative Treatment
Knee pain doesn't announce itself dramatically. It starts as a subtle ache after a long walk, a stiffness when you stand up from sitting, or a grinding sensation when you climb stairs. Over months or years, these small irritations compound into something that genuinely limits your life.
If you're dealing with persistent knee discomfort, you're navigating a confusing landscape of conflicting advice, from rest and ice to surgery and injections. This guide explains what's actually happening inside your knee, which treatments have robust evidence behind them, and how to make informed decisions about your care.
Why Knee Pain Develops and What's Really Going On
Your knee is a marvel of engineering but also a vulnerable joint that bears enormous forces with every step. When pain develops, it's usually because one or more structures inside the joint have degraded beyond their natural capacity to repair.
Osteoarthritis is the most common cause of chronic knee pain in adults over 40. The cartilage that cushions your knee joint gradually wears away, leading to bone-on-bone contact, inflammation, and pain. Early-stage osteoarthritis might cause occasional discomfort, whilst advanced stages produce constant pain, swelling, and severely restricted movement.
Osteoarthritis isn't purely mechanical wear and tear. It's an active disease process involving chronic inflammation, changes in the synovial fluid (the lubricant inside your joint), and alterations in the subchondral bone beneath the cartilage. This understanding has opened up new treatment approaches that target the inflammatory environment rather than just managing symptoms.
Tendinopathy affects the tendons surrounding the knee, particularly the patellar tendon (jumper's knee) and the quadriceps tendon. Overuse, repetitive strain, or sudden increases in activity level cause micro-tears in the tendon fibres. Instead of healing properly, the tendon develops disorganised scar tissue, which is weaker and more pain-sensitive than healthy tendon.
Meniscus tears are another frequent culprit. The menisci are crescent-shaped cartilage discs that act as shock absorbers. They can tear from acute trauma (a sudden twist or pivot) or gradual degeneration. Small tears often cause intermittent catching or locking sensations, whilst larger tears produce persistent pain and swelling.
Why Standard Treatments Often Fall Short
Most people with knee pain follow a predictable treatment pathway. Pain starts, they take over-the-counter anti-inflammatories, perhaps try physiotherapy, and if that doesn't work, they receive a cortisone injection. When cortisone stops helping, surgery becomes the next option.
This approach has significant limitations. Anti-inflammatories reduce pain temporarily but don't address the underlying tissue damage. Long-term use carries risks, including gastrointestinal bleeding and cardiovascular events.
Cortisone injections provide short-term relief by suppressing inflammation, but they don't promote healing. Research shows that whilst cortisone reduces pain for a few weeks or months, it may actually accelerate cartilage breakdown with repeated use. A study in JAMA found that patients receiving cortisone injections experienced greater cartilage loss over two years compared to those who received saline injections.
Physiotherapy helps when the problem is primarily muscular weakness or poor biomechanics. Strengthening the quadriceps and improving knee alignment can reduce stress on damaged structures. However, if the underlying tissue (cartilage, tendon, meniscus) is significantly degraded, exercise alone won't regenerate it.
Surgery is sometimes necessary, particularly for severe structural damage. However, procedures like arthroscopic debridement (cleaning out damaged tissue) have fallen out of favour for osteoarthritis after multiple studies showed they offer no meaningful benefit over sham surgery. Total knee replacement is highly effective for end-stage arthritis but comes with significant recovery time, risks, and a finite lifespan for the prosthetic joint.
How Platelet-Rich Plasma Works for Knee Pain
Platelet-rich plasma (PRP) therapy represents a fundamentally different approach. Rather than suppressing inflammation or replacing damaged structures, PRP aims to stimulate your body's natural repair mechanisms.
The process involves drawing a small amount of blood and concentrating the platelets using a centrifuge. Platelets contain powerful growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-β), and vascular endothelial growth factor (VEGF). These proteins trigger cellular repair, stimulate collagen production, modulate inflammation, and attract stem cells to the injured area.
When PRP is injected directly into the knee joint or surrounding tissues, it changes the local chemical environment. Inflammatory cytokines that perpetuate pain and tissue breakdown are downregulated, whilst regenerative signals are amplified. Damaged cartilage begins producing new matrix, tendons rebuild organised collagen fibres, and blood supply to the area improves.
The evidence supporting PRP for knee osteoarthritis is substantial. A comprehensive meta-analysis published in the American Journal of Sports Medicine analysed multiple randomised controlled trials comparing PRP to placebo, hyaluronic acid, and corticosteroids. PRP injections led to significant improvements in pain relief and functional outcomes compared to all control treatments. The effects typically lasted 6 to 12 months, with some studies showing benefits extending to 24 months.
Another study focusing on early to moderate osteoarthritis (grades 1-3) found that 70% of patients reported good outcomes with PRP injections, with meaningful reductions in pain intensity and improvements in daily function. Patients with end-stage osteoarthritis (grade 4) showed less consistent improvement, underscoring the importance of early intervention before cartilage is completely destroyed.
For tendinopathy, PRP accelerates healing by promoting organised collagen formation within the tendon. Research on conditions like jumper's knee and Achilles tendinopathy shows that PRP injections, often combined with eccentric strengthening exercises, produce superior outcomes compared to rest, physiotherapy, or cortisone alone.
What to Expect from PRP Treatment
PRP therapy for knee pain is performed as an outpatient procedure, typically taking 30 to 45 minutes. After your blood is drawn and processed, the concentrated plasma is injected into the affected area using ultrasound guidance to ensure precise placement.
You might experience some discomfort or swelling for the first few days following injection. This is a normal part of the healing response. Most patients can resume light activities within a few days, though high-impact exercise should be avoided for two to four weeks to allow the regenerative process to take hold.
The timeline for improvement varies. Some patients notice reduced pain within two to three weeks, whilst others see gradual improvement over two to three months. The treatment doesn't produce instant results because it's stimulating actual tissue repair rather than just masking symptoms. Full benefits typically manifest between three and six months.
Most protocols recommend a series of one to three injections spaced four to six weeks apart, depending on the severity of the condition. Maintenance injections every 6 to 12 months may be needed to sustain benefits, particularly for chronic conditions like osteoarthritis.
Who Benefits Most from PRP Therapy
PRP works best for specific patient profiles and conditions. Understanding whether you're a good candidate helps set realistic expectations.
Ideal candidates include individuals with early to moderate knee osteoarthritis (grades 1-3), chronic tendinopathy that hasn't responded to conservative treatment, or partial meniscus tears that don't require surgical intervention. Younger, more active patients often see better outcomes, likely due to higher baseline cellular activity.
Less ideal candidates include those with very advanced osteoarthritis (grade 4, bone-on-bone), acute infections, blood disorders affecting platelet function, or those taking certain medications that interfere with clotting. People with significant mechanical derangement (like a completely torn ligament or large unstable meniscus tear) typically need surgical repair before regenerative treatments can be effective.
PRP is particularly valuable for patients who want to delay or avoid surgery, those who cannot tolerate anti-inflammatory medications, and athletes or active individuals who need to maintain function without the downtime associated with surgical intervention.
Complementary Strategies to Maximise Results
PRP therapy works best when combined with supportive lifestyle measures that optimise joint health and reduce ongoing stress on the knee.
Weight management is crucial. Every kilogram of excess body weight places roughly 4 kilograms of additional force on your knees during walking. Losing even 5-10% of body weight significantly reduces pain and improves function in people with knee osteoarthritis.
Targeted exercise rebuilds strength and stability around the knee joint. Focus on strengthening the quadriceps, hamstrings, and glutes, which absorb forces that would otherwise stress the joint. Low-impact activities like swimming, cycling, and elliptical training maintain cardiovascular fitness without aggravating symptoms.
Nutritional support matters more than most people realise. Omega-3 fatty acids (found in oily fish, flaxseed, and walnuts) have anti-inflammatory properties that may reduce joint pain. Vitamin D and calcium support bone health, whilst glucosamine and chondroitin supplements may provide modest benefits, though evidence is mixed.
Avoid aggravating activities during the healing phase. High-impact sports, deep squatting, and prolonged kneeling place excessive stress on damaged structures. Modify your activities temporarily to give your knee the best chance to repair.
Making an Informed Decision
Knee pain is frustrating because it limits so much of what you enjoy. Whether it's playing with your children, hiking on weekends, or simply walking without discomfort, losing mobility affects your quality of life in profound ways.
The decision to pursue regenerative treatment like PRP therapy should be based on evidence, realistic expectations, and a clear understanding of your specific condition. It's not a miracle cure, but for the right candidates, it offers meaningful pain relief, improved function, and the possibility of delaying or avoiding more invasive interventions.
If you're tired of managing symptoms without addressing the underlying problem, it's worth exploring whether PRP therapy could work for you. A consultation with a qualified practitioner can assess your specific situation, explain what outcomes you can realistically expect, and create a treatment plan tailored to your needs.
