MISHA® Knee System for Knee Arthritis in Northern Virginia

MISHA Knee System at a Glance

• Treatment: Implantable shock absorber placed alongside the inner side of the knee

• Designed For: Selected patients with symptomatic medial-compartment knee osteoarthritis

• Location of Implant: Outside the knee joint capsule

• Joint Preservation: No knee joint surfaces are replaced and no bone-cutting osteotomy is required

• Goal: Reduce load on the painful medial compartment while preserving the natural knee

• Typical Setting: Outpatient surgery for many patients

• Recovery: Early motion and weight bearing are commonly encouraged, with progression based on your surgeon's instructions

• MISHA Providers: Randall S. Peyton, MD, in Sterling and David S. Goodwin, MD, in South Riding

What Is the MISHA Knee System?

The MISHA Knee System is an implantable shock absorber designed for selected patients with osteoarthritis affecting the medial, or inner, compartment of the knee.

Unlike a partial or total knee replacement, MISHA does not replace the damaged joint surfaces.

Instead, the device is positioned alongside the knee, outside the joint capsule, and attached to the femur and tibia. It is designed to share some of the load that would otherwise pass through the painful medial portion of the knee during weight-bearing activities.

This allows the natural knee joint, including its bones, cartilage, ligaments, and other internal structures, to remain in place.

MISHA may help fill a treatment gap for certain patients whose knee arthritis continues to interfere with everyday activities despite nonsurgical treatment but who are not yet ready or appropriate for knee replacement.

Learn more about knee pain and orthopedic knee care.

How Does the MISHA Knee System Work?

The knee experiences substantial force during walking, standing, stairs, exercise, and other weight-bearing activities.

In patients with medial-compartment osteoarthritis, much of that load may pass through the damaged inner portion of the knee.

MISHA functions as a mechanical shock absorber.

When weight is placed through the leg, the device shares a portion of the load passing through the medial compartment. When the knee bends, the implant is designed to accommodate the knee's natural motion.

The goal is to reduce stress on the painful portion of the joint without removing the patient's natural knee surfaces.

MISHA is a symptom-management and joint-preservation treatment. It does not regrow cartilage or cure osteoarthritis.

Learn more about arthritis treatment.

What Is Medial-Compartment Knee Osteoarthritis?

The knee is commonly described as having three compartments:

• the medial compartment on the inner side;

• the lateral compartment on the outer side;

• and the patellofemoral compartment between the kneecap and thigh bone.

MISHA is specifically designed for osteoarthritis involving the medial compartment.

Patients with medial knee arthritis may experience pain along the inner side of the knee, stiffness, swelling, difficulty walking or climbing stairs, or increasing limitations with exercise and daily activities.

Pain location alone cannot determine whether you are a candidate for MISHA.

Your orthopedic surgeon will evaluate your symptoms, physical examination, standing X-rays, alignment, extent of arthritis, bone quality, and previous treatments before recommending the procedure.

Who May Be a Candidate for MISHA?

MISHA is not intended for everyone with knee arthritis.

It may be considered for selected patients who have medial-compartment osteoarthritis and continue to experience significant pain or functional limitations despite appropriate prior treatment.

Potential candidates may have:

• pain primarily associated with medial-compartment knee arthritis;

• symptoms that interfere with walking, exercise, work, or other daily activities;

• persistent symptoms despite appropriate nonsurgical treatment;

• previously tried treatments such as physical therapy, medication, injections, or an unloading brace;

• a desire to preserve the natural knee;

• and a reason to postpone or avoid total knee replacement at the present time.

The decision is based on more than age alone.

Your surgeon must also evaluate the severity and location of arthritis, knee alignment, stability, range of motion, bone quality, health history, activity goals, and other factors.

Who May Not Be a Candidate for MISHA?

Certain knee conditions and medical factors can make MISHA inappropriate.

Patients may not be candidates when arthritis is not primarily limited to the medial compartment or when other conditions make secure implantation or successful recovery less likely.

Examples can include:

• significant arthritis affecting other portions of the knee;

• poor bone quality or osteoporosis;

• active infection;

• inflammatory arthritis such as rheumatoid arthritis;

• certain significant alignment abnormalities;

• substantial stiffness or loss of motion;

• or other medical or structural conditions that make the procedure unsuitable.

These are not the only considerations.

A detailed orthopedic examination and appropriate imaging are necessary to determine whether MISHA is a reasonable option.

What Treatments Are Usually Tried Before MISHA?

MISHA is generally considered after less invasive treatment options have not provided enough relief.

Depending on the patient, prior treatment may include:

Physical Therapy & Exercise

Physical therapy can help improve knee strength, mobility, balance, and movement patterns.

For many people with knee osteoarthritis, strengthening the muscles around the knee and hip can improve function and help reduce symptoms.

Learn more about physical therapy.

Activity Modification

Temporarily modifying activities that repeatedly aggravate knee pain may help reduce symptoms while allowing patients to remain active in other ways.

The goal is not necessarily to stop activity entirely.

Medication

Over-the-counter or prescription medication may be appropriate for selected patients depending on their health history and symptoms.

Knee Bracing

An unloading brace may sometimes help shift pressure away from the painful medial compartment.

Some patients benefit from bracing, while others continue to have significant symptoms despite trying one.

Knee Injections

Selected patients may also consider corticosteroid, viscosupplementation, platelet-rich plasma, or other injections depending on their diagnosis and individual circumstances.

These treatments have different indications and evidence and are not appropriate for every patient.

If these approaches no longer provide enough relief, a surgeon can help determine whether MISHA, another joint-preserving procedure, partial knee replacement, or total knee replacement should be considered.

Read our guide to osteoarthritis treatment options.

What Are the Potential Benefits of MISHA?

MISHA has several features that distinguish it from procedures that replace or reshape the knee joint.

Preserves the Natural Knee

The implant is positioned outside the knee joint rather than replacing the cartilage and bone surfaces.

The patient's natural knee structures remain in place.

No Bone-Cutting Osteotomy

Another surgical approach for selected patients with medial knee arthritis is high tibial osteotomy, which changes the alignment of the leg by cutting and repositioning bone.

MISHA unloads the medial knee without requiring an osteotomy.

Future Knee Replacement Remains Possible

MISHA does not prevent a patient from undergoing knee replacement in the future if arthritis progresses or symptoms eventually require another treatment.

This can be important for patients who want to preserve the natural knee for as long as reasonably possible.

Early Weight Bearing

Because the procedure does not involve replacing the joint or cutting and realigning the tibia, postoperative rehabilitation commonly includes early motion and progression of weight bearing.

The exact schedule should always follow your surgeon's instructions.

Pain & Function Improvement

Clinical studies submitted during FDA review demonstrated meaningful improvements in pain and knee function for many patients through at least two years.

Longer-term studies are encouraging, but MISHA remains a newer treatment than established procedures such as knee replacement, and continued follow-up is important.

MISHA vs. Total Knee Replacement

MISHA and total knee replacement are designed for different patient populations.

MISHA

MISHA preserves the natural knee joint and is intended for selected patients with medial-compartment osteoarthritis who continue to have significant symptoms after prior treatment but are not ready or appropriate for total knee replacement.

The damaged cartilage remains in place.

Total Knee Replacement

Total knee replacement is generally considered when advanced arthritis causes significant pain and loss of function and nonsurgical treatment is no longer providing enough relief.

During knee replacement, damaged joint surfaces are removed and replaced with artificial components.

MISHA should not be thought of as a smaller version of a knee replacement.

It is a different surgical strategy designed for a specific group of patients.

Learn more about total joint replacement.

MISHA vs. Partial Knee Replacement

Partial knee replacement is also used for selected patients whose arthritis is limited to one portion of the knee.

However, the procedures work very differently.

During partial knee replacement, damaged cartilage and bone within the affected compartment are removed and replaced with artificial components.

MISHA leaves the internal joint surfaces intact and instead unloads the medial compartment using an implant positioned alongside the knee.

Whether MISHA or partial knee replacement is more appropriate depends on the severity of arthritis, age, activity level, alignment, ligament stability, symptoms, health, and treatment goals.

MISHA vs. High Tibial Osteotomy

High tibial osteotomy, or HTO, is another joint-preserving procedure used for certain patients with medial-compartment knee arthritis.

During an HTO, the surgeon cuts and realigns the upper portion of the tibia so that weight passes through a healthier part of the knee.

MISHA takes a different approach.

Rather than changing the alignment of the leg, the implant shares load with the medial compartment while leaving the bone alignment intact.

Clinical studies used during FDA review compared implantable shock-absorber treatment with HTO and demonstrated favorable pain, function, and recovery outcomes in the selected study population.

The appropriate procedure depends on each patient's anatomy and clinical situation.

What Happens During MISHA Surgery?

MISHA implantation is performed by an orthopedic surgeon.

The procedure typically involves an incision along the medial side of the knee.

The surgeon exposes the appropriate area of the femur and tibia and uses specialized instrumentation to determine the correct size and position of the implant.

The MISHA device is then secured to the medial femur and tibia with fixation plates and screws.

The absorber spans the area alongside the knee while remaining outside the joint capsule.

The surgeon confirms that the device appropriately unloads the medial knee while allowing the knee to bend through its expected range of motion.

The incision is then closed.

For many appropriately selected patients, the procedure can be performed on an outpatient basis.

What Is Recovery Like After MISHA?

Recovery varies from patient to patient.

Although MISHA is less extensive than joint replacement or an osteotomy in several respects, it is still an orthopedic surgical procedure.

Temporary swelling, soreness, stiffness, bruising, and discomfort around the surgical area can occur.

The First Days After Surgery

Patients are generally encouraged to begin moving the knee early.

Crutches may initially be used for comfort and support.

Your surgeon will provide specific instructions regarding:

• weight bearing;

• wound care;

• swelling management;

• medication;

• knee motion;

• exercises;

• and use of crutches or another assistive device.

The First Several Weeks

Rehabilitation focuses on reducing swelling, restoring knee motion, normalizing walking, and gradually rebuilding strength.

Many patients progress toward full weight bearing relatively early, but the timeline varies.

The presence of swelling or soreness during the early recovery period does not necessarily indicate that something is wrong.

Returning to Exercise & Sports

More demanding activities are added gradually as strength, motion, balance, and comfort improve.

Return to running, higher-impact exercise, recreational sports, or other demanding activities should be discussed with your surgeon and physical therapist rather than based on a fixed timeline.

Learn more about physical therapy at Arthritis & Sports.

What Are the Risks of MISHA?

MISHA implantation is surgery and has potential risks.

Possible complications can include:

• infection;

• persistent pain or discomfort;

• swelling;

• scar formation;

• nerve irritation or injury;

• injury to nearby ligaments or other structures;

• implant loosening or migration;

• loss of implant integrity;

• problems involving the fixation screws;

• adverse reaction to implant materials;

• the need for implant removal;

• or additional surgery.

The procedure may also fail to provide enough improvement in osteoarthritis symptoms.

Your surgeon will discuss the potential benefits, limitations, risks, and alternatives with you before surgery.

Can the MISHA Implant Be Removed?

Yes, removal may be possible if a significant implant-related problem develops or if another surgery becomes necessary.

However, MISHA should still be considered a permanent implanted medical device rather than a temporary brace.

One potential advantage of its joint-preserving design is that the natural knee surfaces are not replaced during the original MISHA procedure.

This can allow future surgical options—including knee replacement—to remain available if needed.

Will MISHA Stop My Knee Arthritis From Progressing?

MISHA is designed to unload the medial compartment and improve symptoms.

It should not be described as a treatment that has been proven to stop or reverse osteoarthritis.

The existing cartilage damage remains present after surgery.

Some patients may eventually experience progression of arthritis and require additional treatment.

The goal is to improve pain and function while preserving the natural knee in appropriately selected patients.

Meet Our MISHA Knee Specialists

Arthritis & Sports offers MISHA evaluation through orthopedic surgeons experienced in knee arthritis, joint preservation, and joint-replacement decision-making.

Randall S. Peyton, MD — Sterling

Randall S. Peyton, MD, is a board-certified orthopaedic surgeon specializing in adult hip and knee reconstruction and joint replacement.

He evaluates patients with knee osteoarthritis at our Sterling office and offers a range of treatments based on the location and severity of arthritis, including joint-preserving and joint-replacement options.

Meet Dr. Randall Peyton.

David S. Goodwin, MD — South Riding

David S. Goodwin, MD, is a board-certified orthopaedic surgeon specializing in sports medicine, arthroscopy, cartilage restoration, and joint-preservation techniques.

He evaluates patients with knee arthritis at our South Riding office and has incorporated MISHA into his joint-preservation approach for selected patients who want to remain active while preserving the natural knee.

Meet Dr. David Goodwin.

MISHA Knee System in Sterling & South Riding, Virginia

Arthritis & Sports evaluates patients for the MISHA Knee System at our orthopedic offices in Sterling and South Riding, Virginia.

Patients throughout Loudoun County and Northern Virginia—including Ashburn, Leesburg, Reston, Herndon, Chantilly, Aldie, and surrounding communities—can meet with a knee specialist to determine whether MISHA or another arthritis treatment is appropriate.

Our locations also offer on-site physical therapy, allowing rehabilitation to be coordinated with your orthopedic treatment when needed.

Visit our Sterling location.

Visit our South Riding location.

Frequently Asked Questions About the MISHA Knee System

Is MISHA a knee replacement?

No. MISHA does not replace the knee joint. It is an implantable shock absorber positioned alongside the medial knee to reduce load while preserving the natural joint surfaces.

Does MISHA remove cartilage or bone?

The MISHA procedure does not replace the knee cartilage or require the bone-cutting osteotomy used in procedures such as high tibial osteotomy. The implant is secured to the femur and tibia outside the joint capsule.

Can MISHA cure knee arthritis?

No. MISHA does not regrow damaged cartilage or cure osteoarthritis. Its purpose is to reduce load on the medial compartment and improve symptoms in appropriately selected patients.

Can MISHA help me avoid knee replacement?

MISHA may allow some patients to continue using their natural knee without immediately undergoing knee replacement. However, it cannot guarantee that knee replacement will never be necessary. Arthritis can progress over time, and some patients may eventually require another procedure.

Is MISHA only for younger patients?

MISHA was developed largely to address a treatment gap among active patients with symptomatic medial knee osteoarthritis who are not yet appropriate or ready for joint replacement. Age is only one part of determining candidacy. The condition of the knee, location of arthritis, alignment, bone quality, symptoms, previous treatment, health, and treatment goals must also be considered.

How soon can I walk after MISHA surgery?

Early weight bearing is commonly part of MISHA rehabilitation. Some patients initially use crutches for comfort and gradually progress as pain, swelling, strength, and walking mechanics improve. Follow the specific weight-bearing instructions provided by your surgeon.

Is MISHA visible or noticeable under the skin?

The implant sits beneath the skin on the medial side of the knee. Some patients may be able to feel the device or experience sensitivity if the area receives direct pressure or impact. Your surgeon can show you where the implant will be positioned before surgery.

What happens if MISHA does not provide enough relief?

If symptoms continue or arthritis progresses, your orthopedic surgeon can reassess the knee and discuss other options. Because MISHA preserves the natural joint surfaces, treatments such as partial or total knee replacement may remain available when appropriate.

Schedule a MISHA Knee System Consultation

If medial knee arthritis is making it difficult to walk, exercise, work, or stay active and conservative treatments have not provided enough relief, you may have options beyond simply continuing the same treatment or proceeding immediately to total knee replacement.

The MISHA Knee System may offer a joint-preserving option for selected patients.

Our knee specialists can evaluate your symptoms, standing X-rays, previous treatments, knee alignment, and activity goals and determine whether MISHA or another knee arthritis treatment is appropriate.

Request a consultation with Arthritis & Sports Orthopaedics in Sterling or South Riding, Virginia.