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Updated: May 16, 2026

Matrix-assisted Autologous Chondrocyte Transplantation for Remodeling and Repair of Chondral Defects in a Rabbit Model
Published on: May 21, 2013
Marrow stimulation improves meniscal healing at early endpoints in a rabbit meniscal injury model
Matthew D Driscoll1, Brett N Robin, Masafumi Horie
1Department of Orthopaedic Surgery, Scott and White Memorial Hospital, Temple, Texas, USA. mdriscoll@swmail.sw.org
Purpose:
To critically evaluate the effect of marrow stimulation (MS) on the extent of healing and the local biological environment after meniscal injury in ligamentously stable knees in a rabbit model.
Methods:
A reproducible 1.5-mm cylindrical defect was created in the avascular portion of the anterior horn of the medial meniscus bilaterally in 18 New Zealand White rabbits (36 knees). In right knees (MS knees), a 2.4-mm Steinman pin was drilled into the apex of the femoral intercondylar notch and marrow contents were observed spilling into the joint. Left knees served as controls. Rabbits were killed in 3 groups (n = 6 rabbits each) at 1, 4, and 12 weeks with meniscal harvest and blinded histomorphometric and histologic evaluation using an established 3-component tissue quality score (range, 0 to 6). One-week specimens were also evaluated for the presence of proregenerative cytokines using immunohistochemistry.
Results:
The mean proportion of the avascular zone defect bridged by reparative tissue was greater in MS knees than in controls at each endpoint (1 week, 55% v 30%, P = .02; 4 weeks, 71% v 53%, P = .047; 12 weeks, 96% v 77%, P = .16). Similarly, there was a consistent trend toward superior tissue quality scores in knees treated with MS compared with controls (1 week, 1.8 v 0.3, P = .03; 4 weeks, 4.3 v 2.8, P = .08; 12 weeks, 5.9 v 4.5, P = .21). No statistically significant differences, however, were observed at the 12-week endpoint. Increased staining for insulin-like growth factor I, transforming growth factor-β, and platelet-derived growth factor was observed in regenerated tissue, compared with native meniscal tissue, in all specimens at 1 week. Staining density for all growth factors was similar, however, in reparative tissue of MS and control knees.
Conclusions:
The results of this study suggest that marrow stimulation leads to modest improvements in quality and quantity of reparative tissue bridging a meniscal defect, particularly during the early recovery period.
Clinical Relevance:
Clinical evaluation of marrow stimulation techniques designed to enhance healing in isolated meniscus repair surgery may be indicated.

