Most of the studies published on the palmaris longus (PL) prevalence are by physical examination methods. None of the reported prevalence studies in Arab populations are based on ultrasonography; hence we have undertaken this study. Our study was performed on 79 (34 male and 45 female) young/adult Arabs. The occurrence of PL tendon was recorded by a physical examination method (Schaeffer’s test), followed by ultrasound measurement of the thickness, width and circumference of the PL tendon at the wrist and the distance between the PL tendon and the median nerve at the wrist, bilaterally. Of 158 wrists examined, the physical examination method revealed the presence of PL tendon in 138 (87.3%) subjects, whereas the ultrasound method revealed 149 (94.3%). Schaeffer’s test gave a false-negative result for 11 cases. The thickness, width and circumference of the PL tendon at the wrist were: 1.14±0.44 mm (right side) & 1.19±0.41 mm (left side); 4.08±1.34 mm (right side) & 4.36±1.26 mm (left side); 8.98±2.94 mm (right side) & 9.45±2.67 mm (left side), respectively. Gender differences in the thickness, width and circumference of the PL tendon at the wrist were: 1.31±0.42 mm (male) and 1.06±0.40 mm (female); 4.61±1.23 mm (male) and 3.93±1.29 mm (female); 10.04±2.59 mm (male) and 8.60±2.82 mm (female), respectively. The distance of the PL tendon from the median nerve (measured 2 cm proximal to distal wrist crease) were: 1.30±0.63 mm & 1.24±0.61 mm on right & left sides; 1.40±0.60 mm & 1.17±0.62 mm in male and females, respectively. The ultrasonographic measurements were statistically significant among genders, while no such significance was detected between the sides. This study has documented both topographic and ultrasonographic description of the PL tendon in a Gulf Arab population; ultrasonography is more reliable for detecting the PL tendon than Schaeffer’s test.
Bhagath K. Potu1, Ahmad A. Alnaggar2, 3, Ayesha Fatima1, Abdel H. Salem1, Raouf A. Fadel1
1 Department of Anatomy, College of Medicine & Medical Sciences, Arabian Gulf University, Kingdom of Bahrain
2Consultant in Radiology, Zagazig University, Egypt & 3Royal Bahrain Hospital, Kingdom of Bahrain