Which surgical approach provides the greatest exposure of the femoral head? A comparison of the Smith-Petersen and trochanteric flip osteotomy approaches

Femoral head fractures are rare injuries which can be technically challenging to treat. Different surgical approaches have been described for the treatment of these injuries but have not previously been directly compared to determine which approach provides the greatest exposure. The purpose of our study was to calculate and compare the surface area exposed by two different surgical approaches to the femoral head (Smith-Petersen and trochanteric flip osteotomy). A qualitative comparison of the location of exposure between the two approaches was also conducted. Dissections were conducted on eight cadaver pelvises, with a Smith-Petersen approach performed on one side and trochanteric flip osteotomy performed on the other (16 approaches total with one of each approach performed on each pelvis). Each approach included a surgical hip dislocation. The amount of femoral head surface area exposed via each approach was calculated using digital image capture software (ImageJ, Bethesda, MD). The calculations of area exposed were then compared using a paired sample t-test. In summary, the Smith-Petersen approach with a surgical hip dislocation is a valuable option for approach to the femoral head. The Smith-Petersen approach provided a significantly greater amount of exposure compared to the trochanteric flip osteotomy (1328mm 2 +/- 379mm 2 versus 1086mm 2 +/- 270mm 2 ; p=0.017). Qualitative comparisons of the location exposure demonstrated that the Smith-Petersen approach provided improved exposure of the anteroinferior head while the trochanteric flip osteotomy provided improved exposure of the posterosuperior head. This study suggests that a Smith-Petersen approach may increase the area exposed compared to the trochanteric flip osteotomy with surgical hip dislocation, particularly for the anteroinferior aspect of the head.