Verifying the Effectiveness of the NUsurface® System

The NUsurface® Meniscus Implant is intended for use in patients with medial compartment pain
that have had a previous partial medial meniscectomy.

Patients who meet the inclusion/exclusion criteria will be assigned by balanced
randomization into one of two groups: the Meniscus Implants versus non-surgical standard of
care. The KOOS (Knee injury and Osteoarthritis Outcome Score) and IKDC (International Knee
Documentation Committee) forms will be used to provide a comprehensive evaluation of the
patients' pre-intervention and post-intervention condition including activity levels, pain,
swelling, locking, stability, support, sports activity, and quality of life assessment.

Inclusion Criteria:

- Had > 6 months ago a medial partial meniscectomy as confirmed by patient history and
MRI

- Is between age 30 and 75 years (inclusive) at the time of study treatment

- Has neutral alignment ±5º of the mechanical axis, as measured from the angle formed
by a line drawn from the center of the femoral head to the medial tibial spine and a
line drawn from the medial tibial spine and the center of the ankle joint

- Has ≥ 2 mm intact medial meniscal rim capable of being fitted with a NUsurface®
device AND is also recommended for the baseline non-surgical (and, if likely to
receive benefit, any injection) therapies to be administered in the study.

- Is willing to be entered into either arm of the study: implanted with the NUsurface
device OR treated with the recommended control arm therapies.

- Is willing and able to attend all follow up visits, complete all study
questionnaires, and undergo required X-ray and MRI schedule

- Is able and willing to understand and sign the Informed Consent Form

- Is able to read and understand the English language

- Has a KOOS Pain of ≤ 75 (100 being the highest attainable and no pain)

Exclusion Criteria:

- Has a symptomatic knee because of a tear that could be addressed by a repeat partial
meniscectomy leaving > 4 mm of medial meniscus rim

- Has evidence of a Outerbridge Grade IV cartilage loss on the medial tibial plateau or
femoral condyle that potentially could contact a NUsurface implant (e.g., a focal
lesion > 0.5 cm2 correlating to a circular defect of > 8 mm in diameter)

- Has complete disruption of the posterior root attachment of the meniscus

- Has lateral compartment pain and Grade III or Grade IV Outerbridge cartilage score in
the lateral compartment

- Has a varus or valgus knee deformity > 5º requiring a tibial or femoral osteotomy

- Has a laxity level of more than Grade II (IKDC), primary or secondary to an injury of
the anterior cruciate ligament (ACL) and/or posterior cruciate ligament (PCL) and/or
lateral collateral ligament (LCL) and/or medial collateral ligament (MCL)

- Has significant trochlear dysplasia, patellar instability or symptomatic patellar
misalignment

- Has patellar compartment pain and Grade III or Grade IV Outerbridge cartilage score
in the patellar compartment.

- Compared to a normal knee, has obvious radiological evidence of medial femoral
squaring, anatomical variance in the medial tibial plateau, or irregularly shaped
cartilage surface

- Had an ACL reconstruction performed < 9 months prior to study treatment

- Has a BMI > 32.5 at the time of study treatment

- Decides to receive (if eligible and an option) allograft medial meniscus
transplantation

- Received any type of prosthetic knee implant made of artificial non-resorbable
plastic, metal or ceramic, not including the NUsurface® Meniscus Implant

- Has a knee flexion contracture > 10º

- Has flexion < 90º

- Had a previous medial femoral condyle surgery (not including microfracture) or High
Tibial Osteotomy (HTO)

- Has insufficiency fractures or avascular necrosis of the medial compartment

- Has an active infection or tumor (local or systemic)

- Has any type of knee joint inflammatory disease including Sjogren's syndrome

- Has neuropathic knee osteoarthropathy, also known as Charcot joint

- Has any medical condition that does not allow possible arthroscopy of the knee

- Has neurological deficit (sensory, motor, or reflex)

- Is currently involved in another investigation of the lower extremity

- Anticipates having another lower extremity surgery during the study period

- Is contraindicated for hyaluronic acid injections (i.e., patients with known
hypersensitivity [allergy] to hyaluronan [sodium hyaluronate] preparations); patients
having knee joint infections or skin diseases or infections in the site of possible
injections

- Is contraindicated for corticosteroid injections (i.e., patients with allergy to any
of the components or with idiopathic thrombocytopenic purpura)

- Has received any corticosteroid knee injections ≤ 3 months prior to study treatment

- Has chondrocalcinosis

- Is on immunostimulating or immunosuppressing agents

- Has ipsilateral or contralateral lower limb joint conditions that may affect
ambulation or KOOS (e.g. have a leg length discrepancy > 2.5 cm [1 inch], causing a
noticeable limp)

- Is a female who is lactating, expecting, or is intending to become pregnant during
the study period

- Is an active smoker

- Is mentally incapacitated (incapable of appraising or controlling conduct) or have
mental disability (e.g., dementia or Alzheimer's)

- Is a prisoner

- Is a patient who has economic incentive not to improve