The relationship between functional absence of the Flexor Digitorum Superficialis to the fifth digit and absence of the Palmaris Longus

Background: The Palmaris Longus (PL) and the Flexor Digitorum Superficialis (FDS) to the fifth digit are both highly variable muscles and there has been controversy as to whether there is a link in their absences.Objective: To determine if there was a relationship between absence of the FDS to the fifth digit and the PL.Design: A prospective study.Setting: Mulago Hospital, Uganda.Methods: The study was conducted using three clinical tests to determine the presence of the FDS in the fifth digit and ten tests to determine the presence of the PL.Results: Two participants had absence of both tendons. The prevalence of FDS agenesis in a hand that had PL was 1.8% while the prevalence of FDS agenesis in a hand without PL was 2.3%. This difference was not statistically significant (p=0.9).Conclusion: There is no relationship between the functional absence of PL and FDS to the fifth digit