Fabella and patella variants: radiographic prevalence, distribution and clinical relevance in a population of black african descent

Abstract

To evaluate the radiographic characteristics and prevalence of fabella and patella variants in an indigenous African population. This retrospective observational study of orthogonal knee radiographs of 377 consecutive subjects was conducted in Lagos, Nigeria, from February 2017 to November 2017. The presence of bipartite/multipartite patella, as well as the presence of fabella were noted. The craniocaudal diameter, anteroposterior diameter, fabello-femoral distance and fabello-tibial distance of the fabella were measured. P≤0.05 represented a statistically significant result. Three hundred and seventy-seven subjects were enrolled. The average age was 41.22±21.37 years with a range of 3-100 years old. There were 158 male (41.9%) and 219 female (58.1%) subjects. The prevalence of fabella was 11.94%. There was a positive correlation between age <47 and ≥47 and occurrence of fabella, P<0.015. There was no statistically significant difference between the mean male and female measured fabella diameters. The overall prevalence of bipartite and multipartite patella in this study was 2.12%. Among male and female subjects, the difference in prevalence of bi and multipartite patella was statistically significantly, P=0.03. The prevalence of fabella and patella variants was lower in this study compared to the findings in other populations and ethnicities. Sex and age were significantly correlated with fabella prevalence. The results reported in this study will facilitate future studies examining the correlations between fabella and patella variants and various knee pathologies in a population of Black African descent.

Prevalence and Radiological Features of Fabella in a Saudi Arabian Population

“…In contrast, another Southeast Asian study from Singapore reported a lower incidence rate (31.25%) (17). Our findings were comparable to the lowest prevalence rates in South Africa (11.94%) and Nepal (12.3%) (18,19).…”

Common fibular nerve palsy due to the Fabella: A review

“…Moreover, fabellae resemble loose bone fragments or osteophytes. The two most prominent methods for establishing a diagnosis accurately were USG and electromyography (Adedigba et al, 2021; Al Matroushi et al, 2021; Dale et al, 2018; Dalip et al, 2018; Takebe & Hirohata, 1981).…”

“…The typical shape of a fabella is circular or elliptical and it measures from 5 to 24 mm, although the biggest fabella described was 30 × 16 × 8 mm (Agathangelidis et al, 2016). Some studies report that fabellae are larger in males, but others find no significant difference (Adedigba et al, 2021; Akkoc et al, 2022; Al Matroushi et al, 2021; Dalip et al, 2018; Kawashima et al, 2007). The bilateral to unilateral fabella ratio is 2:1 or 3:1 according to most studies, with no sex differences (Hauser et al, 2015; Zeng et al, 2012).…”

“…Therefore, depending on individual circumstances, if the fabella is present we observe it as a small cartilage or as a fully developed bone. According to one hypothesis, this also explains why fabella prevalence is higher in Asian countries (as kneeling and therefore mechanical pressure on the fabella is more common there) and why it increases with age (Adedigba et al, 2021; Dalip et al, 2018; Hauser et al, 2015; Kawashima et al, 2007).…”

The Effect of Patellofemoral Maltracking and Patella Type on Symptomatic Bipartite Patella

“…It is detected more frequently in men and is bilateral with a rate of 43%. It may cause anterior knee pain, especially after trauma, sports injury, or overuse [ 1 , 2 ]. Treatment is primarily conservative in symptomatic cases, and surgery may be preferred in cases unresponsive to conservative treatment [ 3 ].…”