Prediction of the Presence of Plantaris Tendon Through Examination of Palmaris Longus Tendon: Is There a Link?

Abstract

SUMMARY:The purpose of this study was to investigate the relationship between palmaris longus (PL) and plantaris (P) tendons and test the clinical usefulness of symmetry patterns between these tendons in Turkish population. This prospective study comprised a total of 240 adult patients (120 men and 120 women) who were admitted to our outpatient clinic with bilateral knee complaints that required bilateral knee MR examination during two years. Standard test (Schaefer's test, oppose the thumb to the little finger while flexing the wrist) was used to assess the presence of the PL tendon both with inspection and palpation. Knee MRI was used to determine the presence of P muscle belly on both sides. We have analyzed symmetric distribution pattern using Mc-Nemar test. The PL was absent unilaterally in 34 subjects (14.2%), while it was absent bilaterally in 17 subjects (7.1%). The P was absent unilaterally in 51 subjects (21.3%), while it was absent bilaterally in 10 subjects (4.2%). If PL was absent in one hand, the chance of having an ipsilateral P tendon was 70.6%. If PL was present in one hand, the chance of having an ipsilateral P tendon was 87.6%. The Mc-Nemar test for symmetry yielded a p value of 0.841 for ipsilateral PL and P muscles. A clear-cut link between Palmaris longus and plantaris tendons could not be demonstrated in this study. Both muscles show different variations independent from each other.