Characterizing Knee Pain and Response to Surgery Using Local Biomarkers
Characterizing Knee Pain and Response to Surgery Using Local Biomarkers
The diagnosis and monitoring of clinically-significant pathologies of the knee remains challenging, and it is unknown why only some injuries become painful or respond to surgical intervention. The limitations of diagnostic magnetic resonance imaging result in arthroscopy that is not always beneficial. Elucidation of biochemical pathways underlying pain in this condition may aid patient selection for surgery and provide pharmacotherapeutic targets. Cytokines or a novel yet uncharacterized protein may be involved in pain following meniscus injury and diagnostic cytokine assay may help physicians differentiate patients that may benefit from arthroscopy from those that may not. Additionally, evaluating post-operative biochemical profiles may provide a method of monitoring surgical outcome and understanding post-operative continuation or remission of pain.
Lavage of the operative and contralateral knee for comparison are performed under anesthesia prior to arthroscopy by the infusion of 10cc sterile saline into the knee joint followed by the immediate withdrawal into the syringe, and storage at -80°C in a tube containing a protease inhibitor. At 12wk post-operative a 10cc lavage is performed on the knee that underwent surgery. Clinical findings for each sample are quantified using gold-standard symptom severity questionnaires.
The specimens will be analyzed for 31 potential biomarkers using a multiplexed immunoassay panel, the results of which will be compared with pre- and post-operative clinical findings and radiographic imaging. Plans do not currently include microarray analysis, but this may be later included.
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: