抄録
The objective of the study was to determine
whether strenuous running exercise produces a
significant amount of fibrosis in the infrapatellar fat
pad (IFP) of the knee and whether intraarticular
injections of hyaluronan (HA) protect fibrosis in the
IFP in a rat running model. Strenuous running
exercise was performed on a rodent treadmill with
5% inclination using Wistar rats. After the exercise,
hyaluronan was injected into the right knee joint
once per week in the HA injection group. In the
treatment control group of the left knee, no injection
was done. Also, the running exercise group
and the sedentary control group received no HA
injection. The IFP was analyzed histologically and
immunohistochemically after 1 week (5 km), 2
weeks (10 km), 3 weeks (15 km) and 6 weeks (30
km). The inflammatory reaction in the IFP was not
prominent at each running stage. A slightly, but
significantly increased amount of inflammatory
cell infiltration appeared during strenuous running.
The amount of collagen fibers increased significantly
at 30 km stage. Histological scores
showed less fibrosis of the IFP in the HA injection
group than in the control group at 30 km run.
Strenuous running exercise may cause fibrosis in
the IFP of runners. Intraarticular HA injection will
inhibit arthrofibrosis of painful runners.
