Clinical Assessment of the Congenital Absence of Palmaris Longus and Flexor Digitorum Superficialis Muscles in Young Saudi Population

Abstract

Introduction. Congenital Palmaris Longus (PL) absence was found in 15%-20.25% of population globally. This condition and Flexor Digitorum Superficialis (FDS) tendon absence in little finger are not known in Saudi Arabia. We studied prevalence of PL and FDS agenesis in Saudi Arabian population. Methods. A random cross-sectional study was carried out after an ethical approval in the Riyadh universities. Schaeffer's test was used to examine PL absence. The Modified test was used to examine FDS absence. Data was analyzed using Microsoft Excel and the SPSS Software version 22. Results. The volunteers, 331, males 164 (49.5%) and females 167 (50.5%), mean age of 23 (SD ± 5.3), showed right hand dominance in 294 (88.8%) and bilateral absence of PL and FDS in 15.1% and 14.8%, respectively. The hand dominance showed no significant relation between PL and FDS absence, p value = 0.788, 0.835, respectively. Generally, we found a weak correlation between absence of the PL and FDS, p value ≥ 0.595. Conclusion. The bilateral absence of PL and FDS was found as 15.1% and 14.8%, respectively. Variation of the FDS tendon absence was an independent entity for the PL absence. The dominance of hands was not related to the tested variables found in PL and FDS agenesis.

Figure 1

Volunteer demonstrating unilateral absence of Palmaris Longus (b).

Figure 2

Volunteer demonstrating full function of the little finger FDS (a). Volunteer demonstrating absence of little finger FDS function (b).

Figure 3

Global prevalence of the Palmaris Longus muscle as studied by Yammine showing overall PLA proportion meta-analysis plot.