What Is the Calypso Knee System?

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The Calypso Knee System is an innovative shock-absorbing implant created by Moximed for individuals with osteoarthritis. By replacing the cushioning that’s been lost in a deteriorated knee joint, the Calypso Knee System intends to reduce pain and improve functionality of the knee joint.

Ultimately, this shock-absorbing implant aims to delay or avoid the need for a more invasive knee replacement surgery altogether. As an outpatient procedure, the Calypso Knee System leaves the knee joint intact, potentially reducing surgical risks, costs, and recovery time.

Doctor bending patient's bandaged knee

Visoot Uthairam / Getty Images

While early successes seem promising, the Calypso Knee System is still in the beginning stages of development and needs to undergo further clinical testing before it may become widely available.

Nonetheless, advances in medical technology offer hope for patients looking to resolve knee issues by stopping disease progression in its tracks.

How the Calypso Knee System Works

The Calypso Knee System works by easing impact on the knee joint, preventing further damage. Similar to the function of the joint’s original cartilage, the cylindrical implant cushions and releases pressure on the knee.

It offers similar benefits to a knee brace, except underneath the skin. The Calypso Knee System protects against wear and tear to halt the further breakdown of the original cartilage and increase knee joint longevity.

The Calypso Knee System is surgically implanted onto the outside of the knee joint. It provides interior support without removing any parts of the patient’s remaining joint.

For now, the Calypso Knee System is only designed for those with mild to moderate arthritis. Individuals with severe knee osteoarthritis likely require more invasive interventions to repair the knee joint.

Ideally, early screening and interventions will give those with osteoarthritis greater treatment options in the future.

What Causes Osteoarthritis?

Osteoarthritis is a common cause of knee pain and stiffness, which can eventually lead to immobility. Unfortunately, the specific cause is unknown.

Certain factors place people at higher risk of osteoarthritis, including:

  • Age: Older adults are at higher risk.
  • Overweight or obesity: Extra weight on the knee increases damage.
  • Bone deformities: Crooked bones or joints can cause issues.
  • Genetics: Osteoarthritis may run in families.
  • Health conditions: Diabetes and hemochromatosis are linked with osteoarthritis.
  • Injuries: New or old knee injuries can lead to arthritis.
  • Physical stress: Playing sports or your job can produce wear and tear.

Aside from surgical intervention, medications, physical therapy, acupuncture, and massage may be recommended to alleviate knee osteoarthritis symptoms.

Implanting the Calypso Knee System

Surgery to implant the Calypso Knee System takes about an hour and is performed on an outpatient basis, meaning patients can go home on the same day as surgery. All that’s required is a four- to five-inch incision on the outer knee to attach the implantable joint unloader in the proper place.

Calypso Implant vs. Knee Replacement

The Calypso Knee System has the potential to become the preferred treatment for patients who are diagnosed with osteoarthritis early. Although knee replacements are an effective solution, they may come with several risks, potential complications, and extensive recovery times.

Here’s how the two procedures stack up against each other at this time, given that more information on the Calypso Knee System is set to unfold in the future:

Calypso Implant
  • Implant availability is limited since it is still in clinical trials in the United States. Results should become available around 2025 to determine future use.

  • The cost for this implant is currently unknown because it is not yet available to the public.

  • The incision is four to five inches long.

  • The required time for recovery is not yet established, but researchers suspect it may take four to six months to ensure safe rehabilitation after the implant.

  • Calypso is an hour-long, outpatient procedure.

Knee Replacement
  • Full and partial knee replacement surgeries have been performed for decades and are widely available.

  • The cost for a knee replacement varies from state to state, but it’s likely to be covered by health insurance since it is a well-established procedure.

  • A traditional knee replacement requires a larger incision of eight to 10 inches.

  • Recovery time after knee surgery is extensive, and may require physical therapy and rehabilitation.

  • Knee replacement surgery takes on average one to two hours, and patients typically stay in the hospital between one and three days after the operation.

Other less invasive surgical options for knee osteoarthritis include removing bone spurs and cartilage, cartilage grafting (transplanting healthy cartilage to fill spaces in the affected knee), or a knee osteotomy (cutting and reshaping the tibia or femur).

Calypso Clinical Trials

The Calypso Knee System is still a fairly new technique for the treatment of osteoarthritis. Moximed is currently funding in-depth clinical trials on this shock-absorber that started in the fall of 2018. The trial has about 80 participants ranging from 25 to 65 years old.

To qualify for this study, participants must have a body mass index (BMI) of 35 or less, weigh under 300 pounds, and have persistent knee pain despite six months of nonsurgical interventions.

The Calypso Knee System trial measures WOMAC (Western Ontario and McMaster University Osteoarthritis Index) pain levels to find participants with a score above 40 to qualify. Trials were open to both male and female participants.

The Calypso Knee System study aims to measure changes in the WOMAC pain and index score over 24 months. Researchers are checking for patient improvements and any adverse effects, including how well the implant lasts. The trial is set to finish in 2025.

Even though the Calypso Knee System isn’t yet available for most people, you can still explore options beyond a partial or total knee replacement with your healthcare provider.

A Word From Verywell

For those who suffer from the pain of osteoarthritis, new treatment options are on the horizon. Currently, the Calypso Knee System is unavailable to the public but looks like a promising alternative to knee replacement surgeries in the future.

Experts suspect that if the trial is successful, patients may be able to access the Calypso Knee System shortly after the trial ends in 2025.

Although the jury is still out, the Calypso Knee System has the potential to improve the lives of millions of people with osteoarthritis, allowing them to delay more invasive procedures and enjoy an active lifestyle.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Edwards C. Medical Technology. Calypso Knee System: cutting down on knee replacements.

  2. NIH Clinical Trials. Calypso Knee System clinical study.

  3. Hospital for Special Surgery. HSS researchers lead trial on new surgical option for knee osteoarthritis.

  4. Arthritis Foundation. Osteoarthritis of the knee.

  5. Foran JRH. Total knee replacement. American Academy of Orthopaedic Surgeons.

  6. The Ohio State University Wexner Medical Center. First-ever surgery tests device to prevent knee replacements.

By Anastasia Climan, RDN, CD-N
Anastasia, RDN, CD-N, is a writer and award-winning healthy lifestyle coach who specializes in transforming complex medical concepts into accessible health content.