Cell Count and Cell Density Decrease as Age Increases in Cadaveric Pediatric Medial Menisci

Melissa Albersheim; William Fedje-Johnston; Cathy Carlson; Steven P Arnoczky; Ferenc Toth; Kevin Shea; Lindsey Harper; Aaron Rendahl; Marc Tompkins

doi:10.1016/j.asmr.2023.100795

Cell Count and Cell Density Decrease as Age Increases in Cadaveric Pediatric Medial Menisci

Arthrosc Sports Med Rehabil. 2023 Oct 15;5(6):100795. doi: 10.1016/j.asmr.2023.100795. eCollection 2023 Dec.

Authors

Melissa Albersheim¹, William Fedje-Johnston^{1

2}, Cathy Carlson², Steven P Arnoczky³, Ferenc Toth², Kevin Shea⁴, Lindsey Harper², Aaron Rendahl⁵, Marc Tompkins^{1

6

7}

Affiliations

¹ Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, U.S.A.
² Departments of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, U.S.A.
³ Laboratory for Comparative Orthopaedic Research, Michigan State University, East Lansing, Michigan, U.S.A.
⁴ Department of Orthopedic Surgery, Stanford University, Redwood City, California, U.S.A.
⁵ Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, Minnesota, U.S.A.
⁶ TRIA Orthopedic Center, Bloomington, Minnesota, U.S.A.
⁷ Gillette Children's Specialty Healthcare, Minneapolis, Minnesota, U.S.A.

Abstract

Purpose: To examine the histologic changes in terms of cellularity, cell density, and nuclear shape in medial meniscal cellularity during skeletal development using pediatric cadaver specimens.

Methods: Medial menisci from 26 pediatric cadavers, 11 female and 15 male (total 36 menisci), were obtained from tissue bank. Mean age of female donors was 34 months (1-108 months) and of male donors was 52 months (1-132 months). Menisci were processed and embedded in paraffin blocks. Each tissue block containing 6 representative areas of meniscus (anterior root, anterior horn, body [n = 2], posterior horn, and posterior root) was sectioned at 4 microns and stained with hematoxylin and eosin for evaluation of chondrocyte nuclei. Each of the 6 representative areas was imaged at 10×; one image on peripheral one-third of section, the second image on central two-thirds of the section. FIJI imaging software was used to measure cell count, cell density, and nuclear morphology (1 = perfect circle). Data analysis included linear mixed models, Type II analysis of variance tests, and pairwise tests with the Tukey correction to assess statistical significance.

Results: Peripheral meniscus was more cellular than central meniscus. The cell count was found to decrease by 14% per year of age. Peripheral cell count decreased at a rate similar to the cell count in the central meniscus. Meniscal cell density was 2× higher peripherally than centrally. Overall average cell density in all locations in the menisci decreased by an average of 14% per year of age.

Conclusions: The results of this study reveal decreases in cell count, cell density, and circularity as age increases in cadaveric pediatric medial menisci.

Clinical relevance: To better understand the development of pediatric menisci at a cellular level and use this knowledge in the future on how to maintain the menisci in a younger, healthier state.