MISHA Knee System for Medial Knee Arthritis

MISHA is an implantable shock absorber placed alongside the inner side of the knee, outside the joint capsule. It attaches to the femur and tibia and is designed to reduce the load transmitted through the arthritic medial compartment.

The implant does not replace the knee's joint surfaces. Its aim is to improve pain and function while preserving the native joint. It does not regrow cartilage or cure osteoarthritis, and it cannot guarantee that knee replacement will be avoided in the future.

MISHA may be considered for patients whose medial-compartment osteoarthritis continues to cause activity-limiting pain despite appropriate prior treatment. Depending on the patient, this may include physical therapy, activity modification, medications, injections or an unloading brace.

Pain location alone is not enough to determine whether MISHA is appropriate. Dr. Horner considers the pattern and severity of arthritis, knee alignment and stability, bone quality, previous treatment, general health and the patient's goals. Advanced arthritis involving other parts of the knee or other causes of pain may point toward a different treatment.

The FDA-authorized indication includes medial knee osteoarthritis with persistent daily-activity limitations despite surgical and/or non-surgical treatment, in patients unwilling or ineligible to undergo total knee replacement because of age or the absence of advanced osteoarthritis.

The first step is to identify what is causing your knee pain. Dr. Horner reviews your symptoms, previous treatment and activity goals, examines the knee, and assesses appropriate imaging. Weight-bearing X-rays help evaluate arthritis and alignment; additional imaging is considered when needed.

Bring any previous knee imaging and a list of treatments you have tried. The discussion will cover whether MISHA fits your situation, the alternatives and what recovery would require.

Dr. Horner is one of the investigator surgeons in the MOTION randomized controlled trial evaluating the MISHA implant. His approach emphasizes careful patient selection and an individualized discussion of expected benefits, limitations and alternatives.

A treatment consultation does not automatically enroll you in a research study. Any discussion of research participation would separately address eligibility, the study procedures and informed consent.

The goal is to reduce pain and improve function, but the degree of improvement varies. Depending on the condition of the knee, alternatives may include continued non-operative care, an alignment-correcting osteotomy, or partial or total knee replacement.

MISHA requires surgery. Potential risks include infection, blood clots, stiffness, persistent pain, irritation from the implant, implant failure and the need for further surgery or implant removal. Dr. Horner will discuss the risks relevant to your health and anatomy before you decide.

Recovery includes wound care, swelling management, progressive rehabilitation and follow-up appointments. Weight-bearing instructions and the timing of driving, work and sport are individualized. Dr. Horner and your therapist will guide progression based on healing, strength and function.

Patients can discuss MISHA and other options for medial knee arthritis with Dr. Horner in Oak Brook, St. Charles and Chicago's Little Village neighborhood. Professional Spanish interpreters are available in person and by phone.

FDA marketing authorization, April 11, 2023

FDA De Novo decision summary

Manufacturer patient resources