Clinical Detection of Presence and Absence of Palmaris Longus Tendon in Somali Population

Abstract

Aim: The aim of this study was to investigate whether the frequency of palmaris longus (PL) absence in Somali population differed from other populations in Africa and the rest of the world and to evaluate its association with sex and side of the limb involved. Methods: Totally 1,000 participants (713 males and 287 females; age range: 7 to 80 years) were tested for the absence of PL tendon using Schaffer’s test. In those with a negative Schaffer's test result, Thompson's test, Mishra's test I, Mishra's test II, and Pushpakumar's "two-finger sign" method were used to confirm its absence. Results: Absence of PL tendon was found in 95 (9.5%) participants. The PL muscle was absent bilaterally in 42 (4.4%) and unilaterally in 53 (5.5%) participants. Unilateral absence of PL was higher in the right hand (3.0%) (p>0.05). Agenesis of the right side in males was significantly correlated with the left side in males (rs=0.556, p<0.01). Right agenesis in females was significantly correlated with its left side (rs=0.625, p<0.01). The incidence of right and left agenesis in females was more strongly correlated than that in males. Age was significantly correlated with left agenesis (rs=0.154, p<0.01) and right agenesis (rs=0.145, p<0.05) in females. Conclusion: The prevalence of PL agenesis in the Somali population is lower than the reported incidence of 15%, but more significantly higher than some of the other African populations. These findings may be helpful, particularly for the surgeons in the region, for orthopedic and reconstructive surgeries using PL grafting.