Determination of congenital absence of palmaris longus tendon with clinical examination and ultrasonography

OBJECTIVES The tendon of the palmaris longus is commonly used as a tendon graft in many reconstructive surgeries. Palmaris longus absence (PLA) was found in 15% among individuals worldwide. In this prospective study, we aimed to conduct an incidence study in which physical examination methods were confirmed by ultrasonography in PLA, and to evaluate the relationship of absence with age, gender, laterality and dominant hand. METHODS The study included 490 cases. They were initially tested to evaluated by physical examination using the Schaeffer's and Hiz-Ediz test for the assessment of the palmaris longus tendon. Additional ultrasonography was performed to confirm its absence in 129 wrists of 78 cases whose tendons could not be visualized or palpated. RESULTS The incidence of tendon absence was 13% by physical examination methods. According to the final results when we added ultrasonography to physical examination methods, the incidence of unilateral, bilateral and overall absence of the palmaris longus were 5%, 9% and 11% respectively. There was no statistically significant difference between individuals with and without PLA in terms of gender, side, age and dominant hand (p = 0.796, p = 0.622, p = 0.397 and p = 0.187, respectively). However, bilateral PLA was statistically significantly higher than unilateral in both genders (p = 0.011). CONCLUSIONS We think that agenesis should be proven accurately by ultrasonographic examination for the final result before any surgical procedure with palmaris longus tendon. Furthermore measuring the diameter of the palmaris longus tendon by preoperative ultrasonography can be useful for surgeons who plan a procedure that requires specific measurements.