Femoral oxygenation during hip resurfacing through the trochanteric flip approach

Abstract

Femoral neck fracture is one of the most common complications of hip resurfacing and considered by some to be related to reduced blood flow as a consequence of the surgical approach. We measured oxygen concentration during hip resurfacing through the trochanteric flip approach (n = 15 patients) and compared this approach with previous data for the posterior and anterolateral approaches. With the trochanteric flip the average femoral oxygenation decreased during the procedure to approximately 50% of that at the start, however it recovered to starting level by the end of the procedure. Preservation of oxygenation with the trochanteric flip was similar to that observed with the anterolateral approach, but with less variation during the procedure. Both of these approaches were superior in terms of oxygenation preservation to the posterior approach which resulted in a dramatic reduction in oxygenation.

Fig. 1A–B

The intraoperative photographs show (A) the neutral position and (B) the hip rotated and flexed with knee flexed position.

Fig. 2

The absolute oxygen concentrations in the femoral head during surgery in Positions 1, 3, and 5 are shown.

Fig. 3

Intraoperative femoral head relative oxygenation changes for each patient during trochanteric approach are shown. The numbers on the curves identify individual patients (n = 15); the lines are alternately dashed and solid for clarity. The baseline value of oxygenation was taken as that at the start of the procedure, therefore, all plots show 100% at the Start. The majority of traces show a decrease in oxygenation during Implantation with a recovery at the End.

Fig. 4

The relative femoral head oxygenation changes averaged for the cohort (n = 15) during the trochanter flip approach and results of the Wilcoxon signed rank test for matched pair analyses are shown (error bars = standard deviations). The data show oxygenation decreased during the procedure but recovered at the end.

Fig. 5

Our comparison between the trochanteric flip, anterolateral, and posterior approaches showed the posterior approach decreased oxygenation by the end of the procedure, in contrast to the anterolateral and trochanteric flip approaches. The anterolateral approach resulted in more variation of oxygenation levels during the procedure than the trochanteric approach.