P026 - Preoperative Changes in the Biomarker Profile of the Knee before Anterior Cruciate Ligament Reconstruction
Abstract
Purpose
The optimal timing of surgical reconstruction after an acute ACL rupture has not been defined. However, there appears to be consensus among surgeons to delay operative intervention in an effort to allow the acute inflammatory phase of injury to subside. The purpose of the current study is to evaluate the change in the concentration of select pro- and anti-inflammatory synovial fluid biomarkers during the interval period between injury and ACL surgery.
Methods and Materials
In patients presenting with an acute ACL injury, a synovial fluid sample was obtained at the time of hemarthrosis aspiration during the initial office visit. An additional synovial fluid sample was collected at the time of ACL reconstruction just prior to surgical incision. Both the acute injury and operative synovial fluid samples were processed with protease inhibitor and the concentrations of 10 biomarkers of interest were determined using a multiplex magnetic bread immunoassay.
Results
There were 16 patients with mean age of 32.16 +/- 8.74 years included in the current study. The acute injury and surgical samples were collected at a mean of 36.8 days apart. From the time of initial presentation to the time of surgery, there was a statistically significant increase in the concentration of RANTES and bFGF, and a statistically significant decrease in the concentration of IL-6, MCP-1, MIP-1β, VEGF, TIMP-2, and IL-1Ra.
Conclusion
The current study identified 8 synovial fluid biomarkers whose concentrations change significantly during the acute inflammatory phase between ACL injury and surgery for reconstruction. This provides an initial step toward a more complete description of the intra-articular microenvironment following knee injuries and how the concentrations of several major players in the acute inflammatory process change over time. As we gain a better understanding of the molecular environment, it may be possible to more accurately identify the optimal timing of intervention after the acute injury.
