Age-Related Changes in the Microvascular Density of the Human Meniscus

Abstract

Background: The microvascular anatomy of the meniscus of the human knee is regarded as a crucial factor in the injury response. Previous studies have investigated the zone-dependent distribution pattern, but no quantitative data exist on vascular density and its age-related changes. Hypothesis/Purpose: The aim of the present study was to histologically analyze the vascular anatomy of the meniscus as a function of age. It was hypothesized that vascular density would decrease with increasing age. Study Design: Descriptive laboratory study. Methods: Human menisci were retrieved from patients who underwent tumor resection or who received total knee replacement because of osteoarthritis. A total of 51 menisci were collected from 28 patients over 9 years (mean age, 25.6 ± 20.4 years; range 3-79 years). Immunohistological staining (alpha–smooth muscle actin) in combination with serial sections and standardized software-based contrast detection were used for the quantitative analysis. Data were analyzed using multiple t tests and the analysis of variance for trends, with a statistical significance level of P < .05. Results: The overall vascular density in the meniscus was lower in the 61- to 80-year age group than in the age groups of 0 to 10, 11 to 20, and 21 to 30 years ( P < .01). A negative linear trend was detected with increasing age (slope, -0.007; P = .016). Within the red-white (RW) zone, a low vessel density was detected for the age groups of 0 to 10 and 11 to 20 years. Beyond these age groups, no vasculature was found in the RW zone. For the white-white (WW) zone, no vessel formations were noted in any age group. Almost 95% of the vessels in the meniscus were located in the capsule. Conclusion: This study reports quantitative histological data for microvascular anatomy as a function of age in a broad cohort of human knee menisci. The overall vascular density decreased with increasing age. No vessel formations were detected in the RW and WW zones after adolescence. Additionally, the capsule is far more densely vascularized than any other part of the meniscus. Clinical Relevance: Vascular density might be an additional factor to consider, along with tear location and patient age, for future treatment options.

Age and anatomical region related differences in vascularization of the porcine meniscus using micro-computed tomography imaging

“…Qualitatively, the neonatal menisci showed greater branching and connectivity compared to adult menisci. Our findings are supported by previous cadaver studies measuring vascular density, where overall vascular density decreased with increasing age in human menisci 14,15,26,27 . In our study, the neonatal menisci were seemingly less wedge shaped and relatively thicker radially compared to the more normal, wedge-shaped adult menisci.…”

The role of patient characteristics and the effects of angiogenic therapies on the microvasculature of the meniscus: A systematic review

“…The search identified 411 articles, of which 352 were excluded based on title and abstract screening, and another twentyfive after full-text reading (Figure 2) [24]. Thirteen studies were included, which reported on patient characteristics affecting the microvasculature of the human meniscus (Table 1) [11][12][13][27][28][29][30][31][32][33][34][35][36], and another eleven studies reported on therapies enhancing the microvascularization of meniscal tissue (Table 2) [37][38][39][40][41][42][43][44][45][46][47]. Quality of the included studies, as assessed by the AQUA tool, is provided in Table 3.…”

“…Ten studies (3 HQ, 3 IQ, and 4 LQ) reported the effect of age on the microvascularization of the human meniscus (Table 1) [11][12][13][27][28][29][30][31][32]35]. Cadaveric studies have shown that the entire meniscus is vascularized around birth, but with increasing age, the vascularity gradually decreases from the inner to the peripheral margin [11,28].…”

“…This finding suggests a decrease in vascularization even within early adulthood; however, the study by Cipolla et al was of low quality and did not provide any statistical analysis [27]. Recently, a study (HQ) of 51 menisci, collected from patients who underwent tumor resection or received TKR (total knee replacement), reported a lower overall vascular density in the menisci in the 61-80 year age group compared to the groups of 0-10, 11-20 and 21-30 years and a negative linear trend was detected with increasing age (slope, À0.007; p = 0.016) [35]. No vessels were detected in the red-white or white-white zone after adolescence within this study group (Figure 1).…”

Recent advances in ligamentous, meniscal and joint-preserving knee surgery: Pushing the limits

“…In 2022 the understanding of the meniscus anatomy [9], biomechanics [10], and pathologies is certainly at the forefront of orthopaedic discussions. In terms of anatomy, numerous ligaments attaching the meniscus to the tibia have been highlighted.…”