Expression of cytokines after meniscal rasping to promote meniscal healing.
OBJECTIVE
We have developed a new surgical procedure of rasping a meniscal surface to repair a tear in the avascular zone. This procedure stimulates vascular induction to the tear, resulting in meniscal healing. The purpose of this study was to elucidate the mechanism of vascular induction and meniscal healing.


METHODS
Randomized trial.


METHODS
A full-thickness longitudinal tear of 5 mm in length was created in the avascular zone of the anterior segment of both medial menisci of rabbits. Meniscal rasping of about 0.5 mm in depth was then done on the femoral surface of the left meniscus from the parameniscal synovium to the inner portion including the longitudinal tear, and the right meniscus was left untreated as a control. After surgery, at 1, 7, 14, 28, 56, and 112 days, 4 rabbits were killed, both medial menisci were resected, and immunohistochemical staining with monoclonal antibodies was used to quantify expression of interleukin-1alpha (IL-1alpha), transforming growth factor-beta1 (TGF-beta1), platelet-derived growth factor (PDGF), and proliferating-cell nuclear antigen (PCNA) on the femoral surface of the menisci. A positive ratio of immunostaining was encountered.


RESULTS
The positive ratio of IL-1alpha, TGF-beta1, PDGF, and PCNA on the rasped surface area reached its peak at 1, 7, 14, and 7 days, respectively, after surgery, and thereafter gradually declined. Although the time course of the positive ratio was different among these cytokines, the positive ratio on the rasped surface was significantly higher than that on the control surface at the early stage of the observation period.


CONCLUSIONS
The cytokine network on the rasped meniscal surface appears to be the key to explaining the mechanism of vascular induction and meniscal healing by meniscal rasping.
Ochi
M
M
Department of Orthopaedics, Shimane Medical University, Izumo, Japan. mitsuo@shimane-med.ac.jp
Uchio
Y
Y
Okuda
K
K
Shu
N
N
Yamaguchi
H
H
Sakai
Y
Y
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D005269:Femur / Q000737:chemistry; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000096:biosynthesis; D008297:Male; D008592:Menisci, Tibial / Q000378:metabolism / Q000601:surgery*; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D011817:Rabbits; D011897:Random Allocation; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000096:biosynthesis; D053773:Transforming Growth Factor beta1
D016207:Cytokines; D007375:Interleukin-1; D010982:Platelet-Derived Growth Factor; D018809:Proliferating Cell Nuclear Antigen; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1