Fixation device related rotational influences in trochanteric femoral fractures:
a radio stereometric analysis of the DHS versus the gamma-nail

Several fixation devices have been developed for treatment of proximal femur
fractures.
Still, treatment of these fractures suffers from relatively high complication
rates.
For treatment of trochanteric fractures extramedullary sliding hip screw
devices (e.g. DHS) and intramedullary nail fixations (e.g. Gamma-nail) are
commonly used.
Both types of implant are related to complications like cut-out of the implant,
nonunion and malunion.
Some of these complications may be accounted for by the induction of rotation
and/or translation of the femoral head-trochanter fragment.

To determine the amount of rotational instability in trochanteric femoral
fractures, related to type of implant and fracture.
The primary goal is to evaluate differences in fracture micromotion (i.e.
translation and rotation) between different implants.
The secondary goal is to relate the micromotion to bone density (Dexa scans),
the position of the femoral head screw(s), the type of implant used, and the
type of fracture.

Sixty patients with an AO31-A2 type trochanteric fracture will be randomly
allocated to treatment with either DHS or Gamma-nail. RSA radiographs are
obtained postoperatively, on the first day, after 6 weeks, 4 months and one
year. One dexa scan will be obtained within 6 weeks postoperatively.

The burden and risk associated with extra radiographs and the insertion of the
tantalum beads of 0.5 mm diameter, used for RSA. Radiation risks are minimal
and should be regarded in the context of the generally high age of this patient
population. Normal X-ray protocol after a hip fracture is performed
postoperatively, at 6 weeks, 4 months, and on indication at 1 years. Patients
might benefit from the extended radiological examination and RSA during their
follow up. In patients that are diagnosed with osteoporosis, treatment will be
started.