Journal of the Medical Association of Thailand Vol 95, No 6:JUNE 2012 0125-2208 95 6 2012 Jun Femoral Head-Neck Diameter and Ratio in Thais: A Cadaveric Study 790 EN Sukit Saengnipanthkul Watchara Techasatien Original Article To report the femoral head and neck diameter in both coronal and sagittal planes, the femoral head-neck ratio, and the difference between sex in a normal Thai population. One hundred two femoral bones without visible previous disease or deformity of the head, neck, and shaft that included 50 male donors and 52 female donors, with an average age of 58.8 years (range 25 to 85) were included in the present study. The measurement of the femoral head and neck diameters was performed by using Vernier calipers (scale 150 x 0.02 mm). The mean head and neck diameters in coronal and sagittal planes in male and female are 45.25, 45.23, 40.28, 40.13 mms (p = 0.000), and 30.80, 25.65, 27.79, 22.08 mms (p = 0.000), respectively. The head-neck ratio in each plane in both male and female are 1.47, 1.45 (p = 0.257), and 1.77, 1.83 (p = 0.016), respectively. The very small average diameter of femoral head, especially in Thai females, should warn surgeons to carefully consider and then, perform hip resurfacing arthroplasty to avoid early complication from neck notching and mal-position. The head-neck ratio of the present study group is high enough to anticipate that postoperative anterior impingement of the neck and acetabulum or limiting hip fl exion is unlikely to occur. Femoral head diameter Femoral neck diameter Femoral head-neck ratio