Rationale for hyaluronan as a synovial fluid replacement

Once the synovial fluid is flushed out of the joint, the balance of the articular environment is lost. Replacement of the synovial fluid with hyaluronan may promote restoration of homeostasis inside the joint.


 

Restoring the articular homeostasis

Studies have shown that exogenous hyaluronan:

  • restores cartilage metabolism following the physiological disturbance caused by irrigating solution15,16

  • protects the articular cartilage and synovial membrane from damage through its functional and structural properties17-25

  • suppresses chondrolysis of cartilage by reducing penetration of fibronectin fragments4

  • restores cartilage glycosaminoglycan content following 6 weeks of joint immobilisation; in addition, treatment with remobilisation and hyaluronan increased glycosaminoglycan content more than remobilisation alone26

  • promotes repair of degraded cartilage, reverses the damage caused by exposure to fibronectin or interleukin-1, and restores proteoglycan to normal levels27

  • promotes meniscal regeneration following meniscectomy and appears to inhibit degeneration of articular cartilage for up to 6 months28,29

  • stimulates collagen remodelling and inhibits swelling during healing of meniscal tears in a rabbit model of total medial meniscectomy30

  • stimulates the synthesis of endogenous hyaluronan31

  • promotes wound healing32 and the healing response following surgical laceration of the anterior cruciate ligament in rabbit models.33

Saline Irrigation
Saline irrigation significantly inhibits cartilage metabolism, as shown by reduced 35S-sulphate incorporation into proteoglycans.
It is restored to normal by the addition of hyaluronan16

 

Meniscal Regeneration
Following partial meniscectomy, hyaluronan promotes meniscal regeneration compared with saline29

 

Healing of damage
Exogenous hyaluronan stimulates healing of damage to the
anterior cruciate ligament (ACL)33