MISHA Knee System vs. Knee Replacement: How Are They Different?
When knee arthritis starts making it harder to walk, exercise, work, or simply get through the day comfortably, treatment options may eventually move beyond medications, injections, or physical therapy.
For some people, that conversation includes the MISHA Knee System. For others, knee replacement may make more sense.
They aren't two versions of the same operation.
The MISHA Knee System is an implantable shock absorber that sits alongside the knee and reduces some of the load passing through the painful inner, or medial, part of the joint. The natural knee surfaces remain in place.
A total knee replacement takes a different approach. Damaged areas of the knee are replaced with artificial components.
Which treatment is appropriate depends on much more than age or pain level. Where the arthritis is located, how advanced it is, how much it affects daily life, and what the rest of the knee looks like all matter.
Key Takeaways
The MISHA Knee System and total knee replacement treat knee arthritis in very different ways.
MISHA is designed for selected patients with medial-compartment knee osteoarthritis who continue to have pain despite previous treatment but aren't ready or appropriate for total knee replacement.
MISHA sits alongside the knee and reduces load on the painful compartment without replacing the natural joint surfaces.
Total knee replacement resurfaces damaged areas of the joint with artificial components and is generally considered when arthritis and symptoms are more advanced.
Partial knee replacement may be another option when arthritis is limited to one area of the knee.
Having MISHA does not automatically prevent a patient from having a partial or total knee replacement later.
No single procedure is right for everyone. Symptoms, imaging, knee alignment and stability, bone quality, previous treatment, overall health, and personal goals all play a role.
What Is the MISHA Knee System?
The MISHA Knee System is an implantable shock absorber designed for certain patients with osteoarthritis affecting the medial, or inner, compartment of the knee.
Instead of entering the joint and replacing damaged surfaces, MISHA is positioned along the inner side of the knee, outside the joint capsule. It attaches to the femur and tibia, and creates another pathway for some of the force that would otherwise travel through the arthritic medial compartment.
The idea is straightforward: reduce stress on the painful area while keeping the patient's natural joint in place.
MISHA received FDA De Novo classification in 2023 as a medial knee implanted shock absorber. Its FDA indication includes patients with medial-compartment osteoarthritis who haven't found enough relief from previous surgical or nonsurgical treatment and who are unwilling to undergo or aren't eligible for total knee replacement because of age or the absence of advanced osteoarthritis.
How Does MISHA Work?
Every time you stand, walk, climb stairs, or exercise, force passes through your knee.
When arthritis affects the inner compartment, some of that force travels directly through damaged, painful joint surfaces.
MISHA acts as a mechanical shock absorber. When you put weight through the leg, the implant shares part of the load that would otherwise pass through the medial side of the knee.
Your natural knee remains in place, including the bones, cartilage, ligaments, and other structures inside the joint.
MISHA does not regrow cartilage, and it doesn't cure osteoarthritis. Its purpose is to reduce load and improve symptoms in patients who are appropriate candidates.
Does MISHA Remove Bone or Cartilage?
No.
MISHA doesn't replace the joint surfaces and doesn't require the same bone preparation used during knee replacement. The implant sits outside the joint capsule and attaches to the femur and tibia.
That's one of the most important differences between MISHA and a knee replacement.
MISHA vs. Knee Replacement: What's the Biggest Difference?
The simplest way to think about it is this:
MISHA unloads and preserves the natural knee. Total knee replacement resurfaces damaged areas of the joint.
MISHA Knee System | Total Knee Replacement | |
Main goal | Reduce load on the painful medial compartment | Replace damaged joint surfaces |
Where the implant is placed | Alongside the knee, outside the joint capsule | Within the knee joint |
Natural knee surfaces | Preserved | Damaged surfaces are prepared and resurfaced |
Typical arthritis pattern | Selected medial-compartment osteoarthritis | Often more advanced arthritis or joint damage |
Treatment approach | Joint preservation and unloading | Joint resurfacing/replacement |
Future knee replacement | May still be possible | The knee has already undergone arthroplasty |
Recovery | Different joint-preservation recovery pathway | Recovery from a larger joint-resurfacing procedure |
History of use | Newer technology | Decades of clinical use |
During a total knee replacement, damaged bone and cartilage surfaces are carefully prepared and covered with artificial components designed to restore movement and function.
Randall S. Peyton, MD, an orthopedic surgeon at Arthritis & Sports who provides both MISHA treatment and knee replacement, explains that the two procedures are designed to address different stages of knee arthritis:
"MISHA and knee replacement solve different problems. One unloads the painful part of the knee while preserving the joint. The other resurfaces a knee that has reached the point where replacement may be the more appropriate option."
Knee osteoarthritis can be treated in several ways, and the right approach depends on the location and severity of the damage. Learn more about our knee arthritis and knee pain care in Northern Virginia.
Is MISHA an Alternative to Knee Replacement?
For some patients, MISHA can be an alternative to having a total knee replacement right away. That doesn't mean it can take the place of knee replacement in every arthritic knee.
MISHA was developed for a specific group of patients with medial-compartment osteoarthritis.
Someone may still have significant pain after trying nonsurgical osteoarthritis treatment options such as physical therapy, medication, injections, or bracing, yet the knee may not have the degree or pattern of damage that makes total replacement the best option.
That's the treatment gap MISHA is designed to address.
A patient with severe arthritis affecting several areas of the knee may be in a very different situation. If joint damage is more widespread, a replacement procedure may do a better job of addressing the underlying problem.
So instead of asking: “Should I choose MISHA or knee replacement?”
A more useful question is: “Which treatment best matches the current condition of my knee?”
Who May Be a Candidate for the MISHA Knee System?
MISHA isn't meant for everyone with knee arthritis.
One of the first things that matters is where the arthritis is located.
The knee has three main compartments:
the medial compartment on the inner side of the knee;
the lateral compartment on the outer side;
and the patellofemoral compartment between the kneecap and thigh bone.
MISHA is specifically designed for osteoarthritis affecting the medial compartment.
A possible candidate may have ongoing pain on the inner side of the knee that interferes with walking, exercise, work, or other everyday activities even after appropriate treatment.
But pain location is only one piece of the decision.
Your surgeon will also consider the severity and location of the arthritis, knee alignment, stability, range of motion, bone quality, health history, treatments you've already tried, and what you'd like to get back to doing.
Inner knee pain by itself doesn't make someone a MISHA candidate.
David S. Goodwin, MD, an orthopedic surgeon specializing in sports medicine and joint preservation, says MISHA candidacy depends on finding the right pattern of knee arthritis—not simply on how much pain a patient has:
“MISHA isn't meant to replace knee replacement for everyone. We're looking for a specific pattern of arthritis where unloading the medial side of the knee and preserving the natural joint may still make sense.”
Who May Not Be a Good Candidate for MISHA?
There are several reasons another treatment may be more appropriate.
For example, arthritis that significantly affects other compartments of the knee may point toward a different option. Poor bone quality, inflammatory arthritis, infection, or other medical and orthopedic factors can also affect candidacy.
The entire knee needs to be considered—not one symptom or one finding on an X-ray. That's why an evaluation matters.
When Is Total Knee Replacement a Better Fit?
Total knee replacement is generally considered when arthritis or other joint damage has become severe enough to cause ongoing pain, stiffness, reduced mobility, or loss of function, and appropriate nonsurgical treatments aren't providing enough relief.
For some people, ordinary activities gradually become difficult. Walking hurts. Stairs take more effort. Getting out of a chair isn't as easy as it used to be. Exercise may become limited, and knee pain can even interfere with sleep.
Still, there's no single age, symptom, or X-ray finding that automatically means it's time for a knee replacement. Your surgeon will look at how much the knee is affecting your life, what the physical examination shows, what appears on imaging, and which treatments you've already tried.
An abnormal X-ray alone doesn't mean surgery is necessary.
When arthritis has progressed further, Dr. Peyton emphasizes that preserving the joint shouldn't become the goal at the expense of choosing the treatment that best fits the knee:
“The goal isn't to delay knee replacement at all costs. The goal is to choose the treatment that best matches the condition of the knee and what the patient needs from it.”
What About Partial Knee Replacement?
MISHA and total knee replacement aren't the only options.
Some patients whose arthritis is limited to one part of the knee may be candidates for a partial knee replacement.
During a partial knee replacement, only the damaged compartment is resurfaced. Healthy portions of the knee are preserved.
That makes it different from both MISHA and total knee replacement.
MISHA vs. Partial Knee Replacement
MISHA doesn't resurface the medial compartment at all.
Instead, the implant works alongside the knee to reduce the load moving through that part of the joint.
A partial knee replacement does replace the damaged surfaces within the affected compartment.
Both approaches preserve more of the natural knee than a total knee replacement, but they accomplish that in very different ways.
Neither option is universally better. The right choice depends on the pattern and severity of arthritis, anatomy, symptoms, activity needs, and individual goals.
Can MISHA Delay a Knee Replacement?
MISHA is designed to help address the treatment gap between failed nonsurgical care and joint replacement. For certain patients, that means it may provide another option during a stage when total knee replacement isn't yet appropriate.
Longer-term research is encouraging, but the numbers need to be interpreted carefully. A 2026 five-year study followed 81 patients who received an implantable shock absorber for medial knee osteoarthritis. Five years later, 73 of the 81 patients, or 90.1%, had not converted to arthroplasty or high tibial osteotomy. Patients also reported meaningful improvements in pain and function compared with where they started.
That does not mean MISHA guarantees that someone will never need a knee replacement. It also doesn't prove that the implant stops osteoarthritis from progressing.
MISHA is best understood as a treatment designed to relieve symptoms and preserve the natural joint in appropriately selected patients—not as a cure for arthritis.
Can You Still Have a Knee Replacement After MISHA?
Yes.
Having a MISHA implant doesn't automatically take partial or total knee replacement off the table later. Because MISHA doesn't replace the natural joint surfaces, arthroplasty can still be considered if arthritis progresses or symptoms can no longer be managed well enough.
That said, a future replacement isn't exactly the same as operating on a knee that has never had MISHA. The existing implant and fixation hardware have to be considered during surgical planning. The exact approach depends on the patient's knee and the type of procedure being planned.
If keeping future knee replacement as an option matters to you, bring that up with your surgeon before deciding on MISHA.
How Does Recovery From MISHA Compare With Knee Replacement?
MISHA and total knee replacement have different recovery paths because the surgeries themselves are different.
MISHA doesn't resurface the knee joint. At Arthritis & Sports, it is an outpatient procedure for many patients, and early movement and weight-bearing are commonly encouraged based on the surgeon's instructions.
A total knee replacement involves healing from a more extensive joint-resurfacing operation. Patients need time for the incision and surrounding tissues to heal while also working on motion, strength, walking, and everyday function.
There's no single recovery timeline that fits everyone. Age, overall health, strength before surgery, the procedure performed, job demands, and individual healing can all affect how quickly someone progresses.
That's also why claims such as “MISHA recovery is X times faster than knee replacement” should be viewed cautiously. The procedures have different goals and are often performed in different groups of patients.
Will I Need Physical Therapy After MISHA?
Rehabilitation after MISHA is individualized. Your surgeon may recommend exercises or formal physical therapy to help restore strength, mobility, balance, and function.
Some patients may need more therapy than others.
Will I Need Physical Therapy After Knee Replacement?
Rehabilitation is an important part of knee replacement recovery. Physical therapy and postoperative rehabilitation may focus on restoring knee motion and strength, improving walking mechanics and balance, and helping you return to everyday activities. The plan advances as healing allows and according to the patient’s goals.
How Do You Know Which Knee Treatment Is Right for You?
There isn't one test that determines whether someone needs MISHA, partial knee replacement, or total knee replacement.
Your orthopedic surgeon has to put several pieces together.
Those include:
where the arthritis is located;
how much joint damage is present;
your symptoms and how they affect your life;
knee alignment and stability;
range of motion;
bone quality;
previous treatments;
overall health;
work and activity demands;
and what you'd like to return to doing.
That's also why two people with similar-looking X-rays may receive very different recommendations.
One person may still be best served by nonsurgical care. Another may fit the criteria for MISHA. Someone else may benefit more from a partial or total knee replacement.
The goal is to match the treatment to the knee—not force the knee into a particular treatment.
MISHA and Knee Replacement Care in Northern Virginia
At Arthritis & Sports Orthopaedics, patients can be evaluated for both joint-preserving and joint-replacement approaches to knee arthritis.
David S. Goodwin, MD, provides orthopedic sports medicine and joint-preservation care in South Riding, including the MISHA Knee System for appropriately selected patients.
Randall S. Peyton, MD, provides MISHA treatment in Sterling as well as partial and total knee replacement for patients whose arthritis and symptoms make joint replacement the more appropriate choice.
Having access to both sides of that treatment spectrum matters.
The purpose of an evaluation isn't to decide ahead of time that MISHA or knee replacement is “better.” It's to understand what's happening inside your knee and determine which approach best fits your arthritis, your symptoms, and your goals.
If knee arthritis continues to limit your activity despite treatment, request a knee evaluation at our Sterling or South Riding office to discuss your options.
Frequently Asked Questions About MISHA vs. Knee Replacement
Is MISHA an Alternative to Total Knee Replacement?
MISHA may be an alternative to immediate total knee replacement for selected patients with medial-compartment knee osteoarthritis. It isn't appropriate for every arthritic knee. Patients with more widespread or advanced joint damage may be better candidates for partial or total knee replacement.
Who Is a Candidate for the MISHA Knee System?
Possible MISHA candidates have symptomatic medial-compartment knee osteoarthritis that continues to interfere with daily activities despite previous treatment. Candidacy also depends on arthritis severity, knee alignment and stability, bone quality, range of motion, health history, and treatment goals.
Does MISHA Replace Damaged Knee Cartilage?
No. MISHA doesn't replace or regrow cartilage. The implant sits alongside the knee and shares some of the load that would otherwise pass through the painful medial compartment, while the natural joint surfaces remain in place.
Can MISHA Prevent Knee Replacement?
MISHA can't guarantee that you'll never need a knee replacement. For selected patients, it may provide a joint-preserving option during a stage when replacement isn't yet appropriate. A future knee replacement may still be considered if arthritis progresses or symptoms worsen.
Can You Have a Total Knee Replacement After MISHA?
Yes. Because MISHA doesn't replace the natural knee surfaces, partial or total knee replacement may remain an option later. Your surgeon will need to account for the implant and fixation hardware when planning any future procedure.
Is MISHA Better Than Partial Knee Replacement?
Neither treatment is universally better. MISHA unloads the medial compartment without resurfacing it. A partial knee replacement replaces damaged surfaces within one compartment. The better option depends on the pattern and severity of arthritis, anatomy, symptoms, and the patient's goals.
Is MISHA Appropriate for Bone-on-Bone Knee Arthritis?
The answer depends on more than the phrase “bone-on-bone.” Your surgeon needs to evaluate which compartment is affected, how advanced the arthritis is throughout the knee, alignment, stability, bone quality, and other factors. Some patients with advanced or widespread arthritis may be better candidates for a replacement procedure.
How Long Does the MISHA Knee System Last?
Five-year clinical results are now available and have shown sustained improvements in pain and function in the study population. That five-year follow-up shouldn't be interpreted as a guaranteed lifespan for the implant. Longer-term research will continue to provide more information about durability.
How Long Is Recovery After MISHA?
Recovery varies. MISHA is performed as an outpatient procedure for many patients, and early motion and weight-bearing may be encouraged according to the surgeon's instructions. How quickly someone returns to work, exercise, and other activities depends on the individual patient and how recovery progresses.
Does Insurance Cover the MISHA Knee System?
Insurance coverage varies by plan and medical-necessity requirements. Patients considering MISHA should confirm coverage and any prior-authorization requirements with their insurer and the treating practice before scheduling surgery.
