Anatomical Structures related to the Fixation Screw of Acetabular Cup in Total Hip Arthroplasty

Won, Ye Yeon; Jahng, Joon Sub; Chung, In Hyuk; Sohn, Keun Soo

Abstract

PURPOSE
This study was conducted to obtain anatomical data useful for transacetabular screw fixation in total hip arthroplasty. MATERIAL AND METHODS: Using 67 hemipelvises of Korean adults cadaver, the variations of external iliac vessels and obturator neurovascular bundle were observed. Forty-nine pelvises were used for the study of vulnerable structures to transacetabular screw inserted through 8 points and 25 pelvises for measuring the thickness of articular cartilage, cortical bone and cancellous bone at each screw penetration site. RESULT: The lengths of S-pin inserted at the inferior, posterior and posteroinferior portion of the acetabulum were more than 20mm. The length of entire bone and thickness of cortical bone measured at the mid point of the posterosuperior portion were longest. The external iliac vessels showed variations in their spatial relationship. At anterosuperior portion, the bone and muscle layer were very thin. The cortical bone of articular side became thicker from center to periphery. The thickness of cortical bone in the pelvic cavity showed different values at different sites.
CONCLUSION
The authors suggest that the structural varieties can be injured when inserting the fixation screw of acetabular cup, and the thickness of cortical and cancellous bone may be useful in total hip replacement.