Outcomes of MAKOplasty Patellofemoral Arthroplasty in Younger Active Patients

The primary purpose of this investigation is to report the short-term clinical outcomes of
patellofemoral arthroplasty implanted using the MAKOplasty knee resurfacing system.

The secondary purpose is to compare the short-term outcomes, complication rates, and
survival rates of this operation to those of our historical controls of patients who
underwent either osteochondral autograft transfer or autologous chondrocyte implantation for
full-thickness patellofemoral articular cartilage lesions. The investigators believe these
data will provide strong evidence to improve the selection criteria for patellofemoral
arthroplasty.

All patients will complete validated questionnaires from the Cincinnati Knee Rating System,
including the Sports Activity and Function Form, the Occupational Rating Form, and the
Symptom Rating Form. Patients will also complete the SF-12 general health questionnaire. In
addition to the above mentioned rating systems, patients will also complete questionnaires
on post-surgical expectations and general fitness level.

Inclusion Criteria:

- Arthroscopically demonstrated localized and isolated full-thickness articular
cartilage lesions (Grade 2B or 3A-B as defined by Noyes & Stabler9) on the
patellofemoral joint.

- Lesion is symptomatic as defined by pain, swelling, locking, or catching that affects
daily activities.

- Patient provides informed consent.

- Patient agrees to comply with postoperative rehabilitation program.

Exclusion Criteria:

- Obesity (body mass index greater than 35).

- Arthroscopically demonstrated full-thickness articular cartilage lesions (Grade 2B or
3A-B) in the other compartments of the knee.

- Uncorrected varus or valgus malalignment

- Uncorrected knee joint instability

- Knee arthrofibrosis

- Patient unwilling to comply with postoperative rehabilitation

- Significant muscular atrophy and weakness that does not respond to rehabilitation

- History of alcohol or drug abuse within 3 years of the operation.

- Disabling or widespread osteoarthritis or other joint disease in any other joint.

- Presence of a significant connective tissue disease, autoimmune disease,
HIV-positive, or immune deficiency syndrome.

- Any contraindications to surgery or other medical disorder that in the opinion of the
principal investigator would interfere with the conduct of the study.