Evaluation of a porous polyurethane scaffold in a partial meniscal defect ovine model.
OBJECTIVE
The objective of this study was to assess the performance of a degradable porous polyurethane scaffold in a partial meniscectomy ovine model.


METHODS
We subjected 42 skeletally mature ewes to unilateral partial excision of the lateral meniscus. In 19 animals the defect was left unfilled; in 23 animals a scaffold was inserted. Knees were examined by magnetic resonance imaging, gross inspection, and histologic inspection of the cartilage of the tibial plateau.


RESULTS
In contrast to what has been previously reported in a complete meniscal replacement model, cartilage damage did not occur under the site of scaffold implantation; this was likely influenced by the rapid infiltration of cells and the dense tissue that formed within the scaffold. Cartilage damage in both groups was located close to the midline of the joint. No significant difference in the condition of the articular cartilage of the tibial plateau was seen between groups up to 12 months postoperatively. This result was influenced by the fact that the partly meniscectomized knees also showed unexpected tissue regeneration within the defect site, which raises concern about the suitability of using a partial meniscectomy as a control in the ovine model.


CONCLUSIONS
Our study has shown that implantation of a polyurethane scaffold in a partial meniscectomy ovine model promotes tissue ingrowth without damaging the cartilage with which it articulates.


CONCLUSIONS
Meniscal deficiency is a common occurrence, the effective clinical management of which is limited by the absence of an off-the-shelf implantable construct.
Maher
Suzanne A
SA
Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA. mahers@hss.edu
Rodeo
Scott A
SA
Doty
Stephen B
SB
Brophy
Robert
R
Potter
Hollis
H
Foo
Li-Foong
LF
Rosenblatt
Lauren
L
Deng
Xiang-Hua
XH
Turner
Anthony S
AS
Wright
Timothy M
TM
Warren
Russell F
RF
D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000473:pathology / Q000601:surgery; D004195:Disease Models, Animal; D005500:Follow-Up Studies; D007150:Immunohistochemistry; D007719:Knee Joint / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods; D008422:Materials Testing; D008592:Menisci, Tibial / Q000473:pathology / Q000601:surgery*; D011140:Polyurethanes; D016062:Porosity; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D011897:Random Allocation; D012038:Regeneration; D012756:Sheep; D034561:Sheep, Domestic; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D013997:Time Factors
D011140:Polyurethanes