Red Light Therapy After Knee Replacement: Easing Pain, Swelling and Stiffness
Your new knee is in, and now the real work begins. The swelling, the stiffness, the aches that seem to come and go, and the question on everyone's lips: "how can I speed this up?"
If you want to actively support your healing, red light therapy is one of the most effective and relaxing ways to do it. It takes just 10 minutes, all you feel is a gentle warmth, and it gets to work right where your body is repairing.
What is red light therapy?
Red light therapy (also called photobiomodulation) uses specific wavelengths of red and near-infrared light that travel into your skin and the tissues beneath.
Inside your cells, this light gives a boost to the mitochondria, the tiny powerhouses that produce energy. With more energy available, cells can get on with what they do best: repairing, renewing and calming inflammation.
What does the research say about red light after knee replacement?
This is where it gets really exciting. Red and near-infrared light has been studied specifically in people recovering from knee replacement surgery.
A 2026 systematic review of randomised controlled trials found that light therapy after knee and hip replacement reduced pain and swelling and improved function.[1] A 2025 review reached a similar conclusion, reporting less pain, less swelling and better knee bend in the early weeks after surgery.[2]
Looking at individual trials:
People who had light therapy after their knee replacement had less swelling at three months and needed fewer strong painkillers in the first month.[3]
Another trial found less swelling and better walking distance within the first week after surgery.[4]
Adding red light around the knee led to better knee bend and function over six weeks.[5]
Can red light therapy help with swelling after a knee replacement?
Swelling is one of the biggest frustrations after knee surgery, and it can hang around for months. Because red light helps calm inflammation and supports circulation, it's a brilliant way to help your body clear that puffiness, as the trials above show.[3][4]
Our clients tell us they notice:
Less puffiness around the joint
More comfortable movement, especially first thing in the morning
Less soreness, so they can get back to doing more of what they love
A lovely sense of calm, as the sessions are warm and relaxing
Can red light therapy help with knee pain and stiffness?
Many people had years of arthritis pain before their operation, and the muscles and tissues around the knee often stay tight and sore while they adjust to the new joint. Research in knee osteoarthritis has shown light therapy can reduce pain and stiffness and improve function,[7] and the knee replacement trials found better movement and function too.[1][5]
A bonus for your scar
Red light has one more trick up its sleeve. A large network meta-analysis comparing laser and light-based treatments for surgical scars found low-level light therapy was one of the most effective options for minimising scar formation.[6] Many clients start once their wound has fully closed, and alongside moisturising, gentle massage and sun protection, it's a lovely way to help the scar soften and fade.
Is red light therapy safe with a metal knee replacement?
Yes, absolutely. Red light therapy uses light, not magnetism or electrical current, so your metal and plastic implant is no concern at all. Joint replacement patients are very welcome on our red light bed.
Before your first session, we'll take you through a quick health questionnaire. We'll check things like medications that make your skin more sensitive to light, so everything is right for you.
Red light therapy and PEMF: the perfect recovery pairing
If you really want to support your knee, red light and PEMF make a brilliant team. Red light works on the skin and the tissues closer to the surface, while our high-intensity PEMF bed reaches deep into the joint and the rest of your body.
If you'd like to give your knee replacement the very best support, we recommend combining red light with PEMF. Read here about how PEMF can further benefit your recovery. Lots of our joint replacement clients book both, and our Recovery Pairing and memberships make that easy.
What does a red light session look like?
Each red light session lasts just 10 minutes. You relax on the bed, the light does its thing, and you're back to your day in no time. Many people like to come regularly while they're recovering, as consistency is where red light really shines.
Tell us when you had your operation and how your knee is feeling, and we'll help you find a routine that suits your recovery.
Frequently asked questions
Is there research on red light therapy after knee replacement?
Yes. Systematic reviews of clinical trials have found that light therapy after knee replacement can reduce pain and swelling and improve function.[1][2]
Can red light therapy reduce swelling after knee surgery?
Yes. Clinical trials have found less swelling in people who had light therapy after knee replacement, both in the first week and at three months.[3][4]
Can red light therapy help knee pain?
Research in knee osteoarthritis and after knee replacement has shown reduced pain and stiffness and better function.[1][7]
When can I start red light therapy after a knee replacement?
Let us know your surgery date and how you're healing, and we'll help you plan from there.
Is red light therapy safe with metal implants?
Yes. Red light doesn't interact with metal or plastic implants, so joint replacements are no problem at all.
Can red light therapy help my knee replacement scar?
Yes, it's a lovely bonus. Research found low-level light therapy to be one of the most effective options for minimising surgical scars.[6]
Does red light therapy hurt?
Not at all. Most people feel a gentle warmth and find the sessions really relaxing.
Can I have red light and PEMF together?
Yes, and it's one of our most popular combinations for recovery.
Book red light therapy in Cockermouth
Whether you're in Cockermouth, Workington, Keswick, Maryport or anywhere across West Cumbria, we'd love to help you and your new knee feel your best. Visit us at 39 Station Street, Cockermouth, book your first red light session online, or send us a DM with RED LIGHT and we'll be in touch.
Ten minutes of warm, glowing light. Your knee will thank you.
References
Eladl HM, et al. Systematic review on the effectiveness of photobiomodulation therapy on enhancing musculoskeletal rehabilitation outcomes after total knee and hip arthroplasty. Photobiomodulation, Photomedicine, and Laser Surgery. 2026;44(10):597-605. https://doi.org/10.1177/25785478261475529
Shetty S, et al. Effect of photobiomodulation on pain and clinical outcomes after total knee arthroplasty in individuals with knee osteoarthritis: a scoping review. Journal of Orthopaedics. 2025;72:133-142. https://doi.org/10.1016/j.jor.2025.11.009
Bahrami H, et al. Low-level laser and light therapy after total knee arthroplasty improves postoperative pain and functional outcomes: a three-arm randomized clinical trial. Arthroplasty Today. 2022;19:101066. https://doi.org/10.1016/j.artd.2022.10.016
Chia WT, et al. The impact of photobiomodulation therapy on swelling reduction and recovery enhancement in total knee arthroplasty: a randomized clinical trial. Photobiomodulation, Photomedicine, and Laser Surgery. 2025;43(2):65-72. https://doi.org/10.1089/photob.2024.0120
Alghamdi BA, et al. Effect of low-level laser therapy on knee range of motion and functional abilities after total knee arthroplasty. Cureus. 2023;15(12):e50893. https://doi.org/10.7759/cureus.50893
Yenyuwadee S, et al. Effect of laser and energy-based device therapies to minimize surgical scar formation: a systematic review and network meta-analysis. Acta Dermato-Venereologica. 2024;104:adv18477. https://doi.org/10.2340/actadv.v104.18477
Ahmad MA, et al. Effects of low-level and high-intensity laser therapy as adjunctive to rehabilitation exercise on pain, stiffness and function in knee osteoarthritis: a systematic review and meta-analysis. Physiotherapy. 2021;114:85-95. https://doi.org/10.1016/j.physio.2021.03.011
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