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

Abstract

PURPOSE:

To elucidate preventive effects of high molecular weight hyaluronan (HMWHA) on the joint capsule of immobilized knees in rats.

MATERIALS AND METHODS:

Unilateral knee joints of rats were immobilized with an internal fixator. Either 50 μl of HMWHA (Im-HA group) or 50 μl 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 inflammation, fibrotic conditions, and hypoxia 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:

CD68 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 CD68 positive cells. The gene expressions of IL-6, IL-1β, TGF-β, CTGF, COL1a1, COL3a1, SPARC, and HIF1-α 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 hypoxic conditions observed in the immobilized joint capsule.

• Authors: Kenji Kanazawa, Yoshihiro Hagiwara, Masahiro Tsuchiya, Yutaka Yabe, Kazuaki Sonofuchi, Masashi Koide, Takuya Sekiguchi, Nobuyuki Itaya, Akira Ando, Yoshifumi Saijo, Eiji Itoi
• Journal: International journal of clinical and experimental pathology (Int J Clin Exp Pathol) Vol. 8 Issue 4 Pg. 3426-40 ( 2015) ISSN: 1936-2625 [Electronic] United States
• PMID: 26097527 (Publication Type: Journal Article)

Chemical References

• Biomarkers
• Hyaluronic Acid

Topics

• Animals
• Biomarkers (analysis)
• Contracture (complications, pathology, prevention & control)
• Disease Models, Animal
• Humans
• Hyaluronic Acid (administration & dosage)
• Hypoxia (complications, prevention & control)
• Immobilization
• Inflammation (complications, prevention & control)
• Injections
• Joint Capsule (drug effects, pathology)
• Knee Joint (drug effects, pathology)
• Male
• Molecular Weight
• Rats
• Rats, Sprague-Dawley
• Synovial Membrane (drug effects, pathology)
• Tissue Adhesions