Prevalence of palmaris longus agenesis among the Urhobo of Delta State, Nigeria

Background: Palmaris longus (PL) is one of the most common muscles in the human body that has anatomical variants of surgical importance. Objectives: The purpose of this study was to find out the frequency of PL agenesis among Urhobo people in Delta State, Nigeria. Materials and Methods: This descriptive study adopted the cross-sectional design, conducted among 400 Urhobo subjects (182 males and 218 females) from the student population of Delta State University, Abraka, Nigeria, using the nonprobability convenience sampling technique. We performed Schaeffer's test to detect the PL tendon in the subjects. If the tendon was still not visualized or palpable, two additional tests (Thompson's and Pushpakumar's tests) were conducted. Data analysis was conducted using the Statistical Package for Social Sciences Version 21.0. The findings were summarized in percentages, while the Chi-square test was used to assess the association of PL agenesis with laterality and gender. Statistical significance was set at a P-value of less than 5%. Results: The tendon of PL was present in 309 (77.25%) and absent in 91 (22.75%) subjects. The agenesis of this muscle showed a significant association with laterality (P = 0.001) but lacked sexual dimorphism bilaterally (P > 0.05). Conclusion: The tendon of PL is absent among some subjects of the Urhobo ethnic group (22.75%). These subjects, therefore, may require alternative tendon sources for reconstructive surgeries. Keywords: Agenesis, palmaris longus, Pushpakumar's test, Schaeffer's test, Thompson's test