Preventing effects of joint contracture by high molecular weight hyaluronan injections in a XXXX immobilized knee model.

@entity32 @entity568 @entity25256 @entity26841 @entity519 @entity12912 @entity16705 @entity22519 @entity3426 @entity1810 @entity35 @entity2528
PURPOSE: To elucidate preventive effects of high molecular weight hyaluronan (HMWHA) on the joint capsule of immobilized knees in @entity35 . Materials and Methods: Unilateral knee joints of @entity35 were immobilized with an internal fixator. Either 50  l of HMWHA (Im-HA group) or 50  l of saline (control group) was administered intra-articularly once a week after surgery. Sagittal sections were prepared from the medial midcondylar region of the knee joints and assessed by histological, histomorphometric, and immunohistochemical methods. Gene expressions related to @entity32 , fibrotic conditions, and @entity519 were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Tissue elasticity of the capsule from both groups was examined using a scanning acoustic microscope (SAM). RESULTS: @entity22519 positive cells decreased in adhesion areas of the synovial membrane after 1 week in both groups. The length of the superficial layer in the synovial membrane of the Im-HA group was significantly longer than those in the control group over a period of 4 to 8 weeks with significantly small numbers of @entity22519 positive cells. The gene expressions of @entity568 , @entity3426 , @entity1810 , @entity2528 , @entity25256 , @entity26841 , @entity12912 , and @entity16705 were significantly lower in the Im-HA group compared to those in the control group. The sound speed of the anterior and posterior synovial membrane increased significantly (a reduction in elasticity) in the control group compared to those in the Im-HA group during weeks 1 to 4. CONCLUSIONS: This study demonstrated that HMWHA injections suppressed inflammatory, fibrotic, and @entity519 conditions observed in the immobilized joint capsule.
