An improved method for cable grip fixation of the greater trochanter after trochanteric slide osteotomy

Abstract

This study proposes a novel method for reattachment of the trochanteric slide osteotomy. The strength of this new fixation system was compared to established configurations. Fifteen sawbone femurs were used. Our configuration used cables above and below the lesser trochanter with a third cable around the shaft of the femur while passing the loose ends through the inferior hole of the cable grip. Displacement of the trochanter was measured with increasing load. Force required for catastrophic failure was also measured. The 3-cable construct resulted in significantly less displacement with increasing load and required a larger force to cause failure (1 cm and 2 cm). We theorize that our configuration produces a biomechanically stronger construct than previously used methods.

Fig. 1

A schematic of the cutting jig with a sample femur demonstrating the plane of osteotomy of the greater trochanter.

Fig. 2

Configuration 1.

Fig. 3

Configuration 2.

Fig. 4

(A and B) Configuration 3.

Fig. 5

(A) Photograph of the Instron machine with a sample femur loaded to demonstrate plane of application of force on the osteotomized fragment. (B) Photograph demonstrating direction of force application on the osteotomized fragment.

Fig. 6

Force applied to displace to 1 cm (black) and 2 cm (gray).

Fig. 7

Displacement of construct with increasing force being applied.