Patellofemoral osteoarthritis (PF OA) is a common and often frustrating knee condition that affects about one in five adults over age 45 in the UK. This form of arthritis targets the joint where the kneecap ( patella ) meets the thigh bone (femur), leading to pain with everyday movements like climbing stairs, walking up slopes, or squatting. For many people, these persistent symptoms limit mobility and take a toll on quality of life—sending them in search of better, longer-lasting treatments. One exciting option gaining attention is Arthrosamid , a gel injection designed to cushion the knee and relieve pain right where it's needed most. In this article, we’ll explain what patellofemoral osteoarthritis is, how Arthrosamid works, the clinical evidence behind it, the expert approach at MSK Doctors, and what to know before trying this treatment.

What Is Patellofemoral Osteoarthritis?

Patellofemoral osteoarthritis is a type of “wear and tear” arthritis affecting the front of the knee, where the kneecap glides over the femur. Over time, the smooth cartilage that protects this joint can break down, causing bone surfaces to rub against one another. This leads to stiffness, swelling, and aching pain—most often felt when going up or down stairs, cycling, squatting, or simply standing up from a chair.

Knee osteoarthritis overall is very common, but having patellofemoral involvement makes simple movements much more painful and frustrating for many people. Because traditional treatments like painkillers , physiotherapy , or steroid injections often provide only short-term relief, patients and clinicians increasingly look to new solutions such as Arthrosamid .

How Does Arthrosamid Work?

Arthrosamid is an injectable gel made from polyacrylamide hydrogel —comprised of 2.5% gel suspended in water. Once injected into the knee joint , Arthrosamid binds to the lining (synovial membrane), forming a soft, lubricating cushion that increases the joint’s natural thickness and slipperiness. This reduces friction and pressure, directly easing pain in the patellofemoral compartment.

Unlike steroid or hyaluronic acid injections , which may wear off in weeks or months, Arthrosamid is specially formulated not to break down quickly inside the body. That means it can provide longer-lasting relief. Studies have shown this gel injection can help reduce knee pain and improve mobility for up to two years—without significant safety concerns or severe side effects.

What Does the Clinical Evidence Say?

Clinical research shows Arthrosamid is effective as a targeted treatment for PF OA pain. Trials comparing Arthrosamid to traditional hyaluronic acid injections have found that it works as well as, or better than, established therapies—especially over the course of a year. Patients with a healthy weight, under age 70, and with mild to moderate osteoarthritis seem to experience the greatest benefit.

Long-term studies report that people treated with Arthrosamid typically have less knee pain and improved movement, based on widely-used outcome measures like the Visual Analogue Scale (VAS), Oxford Knee Score (OKS), and Lysholm score. Most side effects are mild and short-lived, usually consisting of injection site tenderness .

Still, experts acknowledge there is no single gold- standard treatment for isolated patellofemoral osteoarthritis . While physiotherapy and taping are often recommended, their benefits may be temporary. Injection therapies like Arthrosamid represent an innovative new avenue, but further large studies will help refine patient selection and long-term outcomes.

Expert Care from Professor Paul Lee and MSK Doctors

Getting the best results from Arthrosamid isn’t just about the injection—it’s also about receiving expert care. At MSK Doctors , Professor Paul Lee and his skilled team specialise in diagnosing and treating musculoskeletal conditions . They use ultrasound guidance to place the injection exactly where it’s needed, maximise its effectiveness, and minimise discomfort.

Patients at MSK Doctors also benefit from careful assessments, clear explanations of the procedure, and thoughtful aftercare advice. This supportive approach helps build confidence and ensures the best possible results from each treatment.

What Should Patients Know Before Treatment?

Arthrosamid can be an option for adults diagnosed with patellofemoral osteoarthritis whose knee pain impacts daily activities and hasn’t responded to standard treatments. However, it isn’t suitable for everyone. People with active infections , certain skin problems at the injection site, previous permanent knee implants, or recent knee surgery (within 6 months) should avoid the treatment. It’s also not advised for those with bleeding disorders or those on specific blood thinners, and special caution is needed during pregnancy, breastfeeding, or in cases of autoimmune diseases .

The treatment is minimally invasive, usually done with local anaesthetic. After the procedure, it’s best to rest the knee for 24 hours and avoid strenuous or high-impact activities for about three days. Mild discomfort—if it occurs—usually responds well to paracetamol and ice packs. Most patients are able to return to low-impact activities like cycling soon after, often with less pain and greater ease. For some, Arthrosamid may help delay or avoid the need for surgery such as total knee replacement .

Research continues to evolve, and while more robust studies are needed, individual assessment and a personalised approach remain key.

Conclusion

Arthrosamid represents a promising new approach for people living with patellofemoral osteoarthritis . By cushioning and lubricating the knee, it offers targeted, long-lasting relief right where it’s needed. When administered by experienced clinicians like Professor Paul Lee and the MSK Doctors team, Arthrosamid can help reduce pain and get people moving more comfortably again. As always, consulting a qualified healthcare professional will help ensure this treatment is right for your unique needs.