nSTRIDE® knee injection is an alternative treatment to knee replacement surgery

The nSTRIDE® APS Kit is a cell-concentration system that reduces pain and inflammation in the knee through a knee injection. It functions by isolating anti-inflammatory cytokines and anabolic growth factors from whole blood so that they can be reintroduced to the body at the site of inflammation and pain. There is evidence that it can provide sustained pain relief for more than 18 months. The system was developed in response to the treatment gap.

What is it like having an nSTRIDE® knee injection?

Unlike surgery, nSTRIDE® is a rapid procedure from which there is little recovery time. Blood is taken from your arm and then processed through multiple steps during the following hour. The final product of the processing is introduced to the knee by injection. You can go home within an hour.

illustration showing the nstride knee injection Autologous Protein Solution Kit

“A single intraarticular nSTRIDE® APS injection is safe (similar to saline injection) and continues to provide pain improvement at 1 year”.

Kon E, Engebretsen L, Peter Verdonk P, Nehrer S and Filardo G. “Two-year Clinical Outcomes of An Autologous Protein Solution Injection For Knee Osteoarthritis.” ICRS 14th World Congress, presented 2018.

The Treatment Gap

15% of people over 45 years of age suffer from symptomatic knee arthritis. Despite participating in non-operative management programmes, one-quarter of this group find walking difficult. A significant number of arthritic knee sufferers will have difficulty walking. Family doctors (GPs), physiotherapists and surgeons can advise patients in the treatment gap. A broad spectrum of options beginning with non-surgical treatments and through to surgical procedures are available, before ultimately resorting to a knee replacement.

What is the treatment gap? Am I in the treatment gap?

If you have a disability due to knee pain despite treatment and have been told “your knee is not ready for knee replacement,” then you are in the treatment gap. The treatment gap is defined as the time spent between when the non-surgical treatment stops working and when your knee is suitable for joint replacement.


On average, the treatment gap straddles a period of 10 years, although, if arthritis onset is present at a younger age, then, it may stretch over most of a person’s adult life. 1% of the entire population is thought to be in the treatment gap. Consequently, in the Bristol area alone there are over 5,000 individuals for whom non-operative treatment has or will not deliver a satisfactory result and for whom surgery will not be an option.

Why has my doctor not booked me in for surgery?

Doctors are frequently asked “my knee seems to be heading for a total replacement. Why can’t we just get on and do it?” When the medical professional opts to first try a less invasive solution, patients are left with the impression that a lower-cost treatment is being sought or that the doctor is not convinced as to the severity of the ailment.


Why are surgeons reluctant to immediately recommend a knee replacement? The answer lies in the outcomes. Surgeons know that if a knee replacement is performed before bone on bone arthritis is present then fewer patients will be satisfied with the final result.


Historically, in these cases, partial knee replacements present a satisfaction rating of 95% whereas, total knee replacements come in at 70%. When performed on young patients with mild arthritis, this score drops to less than 50%. Surgeons will always seek to maximise patient satisfaction and for this reason, they may be reluctant to immediately suggest more radical procedures.

Managing my arthritic knee

Arthritic knees result in pain and stiffness. As the disease progresses, the joint gradually becomes stiffer and pain more intense. This may lead to night pain, joint swelling or leg deformity as the stiffness becomes ever more severe.


Until such time as a satisfactory knee replacement is possible, how can pain and discomfort be managed?


Despite claims to the contrary, frequently from dubious internet sources, modern medicine has yet to come up with a solution to reverse the arthritic condition. However, several effective treatments are available to control or eliminate pain.

How can arthritic pain be controlled or eliminated?

Subjecting younger patients to surgical procedures has proven not to be the best path. Effective non-operative treatments are the better option, though some of the more advanced treatments may not be offered by the family doctor. Addressing inflammation is a key element of treatment—symptoms of arthritis arise from a combination of mechanical irregularities and inflammation.

What are the treatments available to me?

Pain killers

This is usually the first port of call. Most patients benefit from using appropriate doses of paracetamol, anti-inflammatory drugs (such as ibuprofen, naproxen, celebrex and aspirin) and opioid drugs (such as codeine, oramorph, tramadol and certain patches) over limited periods. These medications are not benign as some can have potentially serious side-effects, some are addictive and they may only be effective over short periods. Creams applied directly to the knee may also temporarily alleviate pain.



This is an umbrella term for numerous dietary supplements including glucosamine, chondroitin, turmeric, cumin, grapes soaked in gin and any number of other treatments. CBD oil is also rapidly becoming a popular choice. Despite the abundance of studies, there is little scientific evidence to support these treatments as comprehensive solutions. However, on occasion, successful results have been reported and, as long as these do not create a financial or health burden, some doctors will not object to supporting patients in experimenting with these alternative medications.


Activity modification

Whereas some may find this helpful, others find they do not benefit greatly from the added exertion. There is no doubt that some exercises (squats, lunges, impact activities, rotation, tackling) are punishing on the knees. Other exercises may be kinder, such as swimming, cycling and rowing, among others. Building up from the less strenuous exercises to more adventurous levels may be the best solution.


Weight loss

Being overweight puts a huge amount of pressure on the knee cartilage. Some studies suggest that a 5% loss of body mass can result in a 50% reduction in knee pain. However, doctors acknowledge that exercise and increased physical activity can be difficult when experiencing knee pain and that unsupervised diets may only achieve temporary weight loss. Consulting nutritionists and bariatric surgeons is a path to a weight loss programme that will provide a sustained result. Exercises should be tailored to minimise knee pain whilst maintaining active.


Physiotherapy and exercise

It may seem very counterintuitive but increased physical activity, in this case, can be very helpful for certain patients. Physiotherapy can be hugely beneficial in treating stiffness and restoring a normal walking pattern. Exercises should be tailored to minimise knee pain whilst maintaining active, there are specific classes aimed at supporting people with arthritis stay active.



This is a form of surgery that can be helpful where just one part of the knee is affected by arthritis, the pressure is transferred from the arthritic part of the knee through the unaffected area. This form of surgery can delay the ultimate date for a knee replacement. Correcting lifelong cases of bow leg or knock knee, can release the pressure on overworked joints.



Various injected therapies are available, as described below. Rarely they can cause complications such as infections or allergic reaction. They differ greatly in their duration of efficacy and price.

  • Steroid (a.k.a., Cortisone) injections: These have proven helpful for a limited period by triggering a powerful anti-inflammatory effect. A first time application can provide a huge relief for up to three months. A second dose is less effective and subsequent injections provide diminishing relief. The effects on the joint of the knee are not well understood and may be detrimental.
  • Hyaluronic acid injections: This viscous fluid is similar to the natural lubricant in the joints and was initially proposed as a shock absorber or lubricant. Current thinking is that it works more as an anti-inflammatory, it is usually effective for a 6-12 month period. The latest NICE guidelines do not support its use as an approved treatment for arthritis as it has yet to meet the NHS’s value for money criteria. Admittedly, several recent systematic reviews support its use. Patients should investigate the potential cost-benefit.
  • Stem cell injections: This treatment has received much media attention. Hopes were high that it would regenerate cartilage. Unfortunately, this is currently a very expensive option and outcomes are patchy. Science fiction or a miracle cure? Only time will tell but currently, this is not a treatment with a sound evidence base.
  • nSTRIDE® biologic PrP injections: nSTRIDE® differ from standard PrP injections. This new neutrophil depleted PrP (platelet-rich plasma) product is in the market at a price point well below the stem cell injection solutions and has progressed well through rigorous testing. Laboratory studies, veterinary studies, safety testing and human clinical trials have been performed by Zimmer-Biomet (a leading global biotech company). Efficacy data looks promising, with good results for pain relief beyond 18 months.

People suffering from painful knee arthritis fit into one of three categories.

  • Conservative Treatments

  • Treatment Gap

  • Knee Replacement

Conservative Treatments

Symptoms controlled by conventional care management.


Treatment Gap

Patients where conservative treatment has failed but they’re not ready for knee replacement.


Knee Replacement

Symptoms only controlled by partial or total knee replacement surgery.


Clinical and economic consequences of the treatment gap in knee osteoarthritis management. London et al.  March 2011. Medical Hypotheses 76(6):887-92

Are you looking for non-operative treatments for your knee pain?