Background
Chondrocyte apoptosis follows trauma and triggers ostearthritis(OA). The prevention of apoptosis prevents OA. Hyaluronic acid (HA) suppresses chondrocytes apoptosis in instability and chemical models of OA.
Purpose
The aim of this study was to quantify the percentage of apoptotic cells in a contusion model of OA and assess whether intra-articular injection of high doses of HA immediately after trauma, can reduce chondrocytes’ apoptosis.
Methods
Forty knees of adult rabbits were impacted trice with a 1kg block released through a cylinder, 1 meter tall (29.4 Joules). Subsequently, 2ml of HA were injected in one knee and 2ml saline in the contra-lateral knee. Medications were repeated twice a week during 30 days, after which the animals were sacrificed. Specimens were prepared for optical microscopy and terminal deoxynucleotidyl transferase end labeling (TUNEL) staining.
Results
The apoptosis rate of the contusion model was 68.01% (+ 19.73), a higher rate than those described. HA reduced significantly the rate of apoptosis to 53.52% (+ 18.09) (p <0.001).
Conclusion
Intra-articular HA starting immediately after trauma, reduces impact-induced chondrocytes’ apoptosis rates in rabbits.
CLINICAL RELEVANCE
Prevention of apoptosis is important for the prevention of post-traumatic OA. HA reduces the rate of apoptosis.
KEYWORDS: Chondrocyte; Hyaluronic Acid; Apoptosis; Rabbit; Traumatism; Knee / histology