Cyamella (a popliteal sesamoid bone) prevalence: A systematic review, meta‐analysis, and proposed classification system

Abstract

The cyamella is a rare, generally asymptomatic, knee sesamoid bone located in the proximal tendon of the popliteal muscle. Only two studies have investigated cyamella presence/absence in humans, putting ossified prevalence rates at 0.57%–1.8%. We aim to (a) determine cyamella prevalence in a Korean population, (b) examine coincident development of the cyamella and fabella, and (c) perform a systematic review and meta‐analysis on the cyamella in humans. Medical computed tomography scans of 106 individuals were reviewed. A systematic review and meta‐analysis were performed following PRISMA guidelines. Cyamellae were found in 3/212 knees (1.4%), and presence/absence was uncorrelated to height, age, and sex. The cyamella was not found coincidentally with the fabella, although the statistical power was low. Our systematic review/meta‐analysis revealed cyamellae were generally asymptomatic and ossification could occur at 14 years. Cyamellae were equally likely to be found in both sexes, knees, one or both knees, and there appeared to be no global variation in prevalence rates. Cyamellae were found in three distinct locations. There is little support for the role of intrinsic genetic and/or environmental factors in cyamella development in humans. However, the apparent phylogenetic signal in Primates suggests genetics plays a role in cyamella development. We propose a cyamella classification system based on cyamella location (Class I, popliteal sulcus; Class II, tibial condyle; Class III, fibular head) and hypothesize locations may correspond to distinct developmental pathways, and cyamella function may vary with location.

The Critical Appraisal Tool for Anatomical Meta‐analysis: A framework for critically appraising anatomical meta‐analyses

“…In this article, we introduced the CATAM rubric and used it to critically appraise a recently published anatomical MA (Kacprzyk et al, 2020). There have been other anatomical MAs recently published (Aldabe et al, 2019; Bellier et al, 2020; Berthaume & Bull, 2021; Cheruiyot et al, 2021; Dreher et al, 2018; Graves et al, 2017; Harvie et al, 2019; Koziej et al, 2020; Morelli et al, 2019; Nallikuzhy et al, 2018; Roberts et al, 2021; Sirico et al, 2019; Solewski et al, 2021; Stefura et al, 2018; Tomaszewska et al, 2018; Tomaszewska et al, 2018; Tomaszewski et al, 2017; Tomaszewski et al, 2017; Vikse et al, 2016a, 2016b; Whitley et al, 2020; Yammine, 2013, 2014b, 2014c, 2014d; Yammine et al, 2015; Yurasakpong et al, 2021). We believe that the running paper that we used is an exemplary anatomical MA (Kacprzyk et al, 2020).…”

The trabecular architecture of the popliteal sesamoid bone (cyamella) from a New Zealand white rabbit (Oryctolagus cuniculus)

“…Le Minor (1992) looked at the prevalence of the cyamella in 34 primate genera and reported that the cyamella does not appear in all nonhuman primate genera, but when it does, it has a half‐ellipsoid shape with one flat articular surface and a second rounded nonarticular surface. In humans, the occurrence of the cyamella is low, estimated at 1%–2% of individuals (Berthaume & Bull, 2021). Two studies looked at the cyamella in New Zealand white (NZW) rabbits ( Oryctolagus cuniculus ; Lagomorpha Crum et al, 2003; Orhan et al, 2005).…”

“…In humans, the occurrence of the cyamella is low, estimated at 1%-2% of individuals (Berthaume & Bull, 2021). Two studies looked at the cyamella in New Zealand white (NZW) rabbits (Oryctolagus cuniculus; Lagomorpha Crum et al, 2003;Orhan et al, 2005).…”

Coexistence of symptomatic cyamella and multiple fabellae: A case report

“…The cyamella, an ossified cartilaginous body within the proximal tendon or at the musculotendinous junction of the popliteal muscle, is a rarely observed and generally asymptomatic sesamoid bone of the knee. [1][2][3][4] The prevalence of ossified cyamella is reported to be between 0.57 and 1.8%. 3 A symptomatic cyamella is very rare and described in the literature only in few case reports.…”

“…[1][2][3][4] The prevalence of ossified cyamella is reported to be between 0.57 and 1.8%. 3 A symptomatic cyamella is very rare and described in the literature only in few case reports. 2,4,5 The fabella is also a sesamoid bone typically found in the lateral head of the gastrocnemius.…”