Characterizing Knee Pain and Response to Surgery Using Local Biomarkers

Our study population includes adult males and females presenting to a single orthopaedic surgeon for arthroscopic management of acute or chronic knee pain due to a mechanical derangement discernable by MRI.

Subjects are selected using a probability sampling scheme, such that every knee arthroscopy patient that presents, without exclusionary criteria described above, is offered enrollment in the study. To date, approximately 85% of patients consent to enrollment, with no apparent sampling bias. Additionally, we are using repeated measures (matched random sampling) to evaluate the role of mediators of knee pain, and to assess the potential of utilizing expression profiles to monitor surgical outcome. For example, clinical indicators and biomarker expression profiles taken peri-operatively are compared to those obtained 12 weeks post-operatively in the same subject.

Inclusion Criteria:

•Adult patients with knee pain (acute or chronic) who had failed conservative treatment and elected for arthroscopic management. Indications for surgery included the presence of mechanical symptoms on history, a physical examination positive for McMurray's maneuver or joint line tenderness or both, absence of severe joint space narrowing on plain radiography, and the presence of grade III signal changes on MRI in an anatomic location consistent with the history and physical examination.

Exclusion Criteria:

• Less than 18 years old.
• Recent (within three months) intra-articular corticosteroid injection and past or current medical history of autoimmune disease (i.e. rheumatoid arthritis).
• In addition, no patients involved in a worker's compensation claim or personal injury litigation were enrolled in the study.