Cadaveric biomechanical study comparing an integrated dual screw intramedullary nail (InterTAN) to a single lag screw cephalomedullary nail (Gamma 3) for unstable OTA 31-A2 intertrochanteric fractures in osteopenic bone, using a paired hemi-pelvis model that simulates 3 months of physiologic loading including pelvic rotation.
When fixing an unstable intertrochanteric fracture (OTA 31-A2) in an osteopenic patient, the predominant failure mode under physiologic loading is femoral head rotation about the lag screw axis — not simply varus collapse — and an integrated dual screw nail design provides significantly greater rotational control and is more forgiving when lag screw placement is imperfect (TAD >25 mm).
For single lag screw constructs, nail position on the lateral view matters: even a slightly anterior or posterior tip within an acceptable TAD correlates with increased rotational failure risk.
Cadaveric biomechanical study comparing an integrated dual screw intramedullary nail (InterTAN) to a single lag screw cephalomedullary nail (Gamma 3) for unstable OTA 31-A2 intertrochanteric fractures in osteopenic bone, using a paired hemi-pelvis model that simulates 3 months of physiologic loading including pelvic rotation.
When fixing an unstable intertrochanteric fracture (OTA 31-A2) in an osteopenic patient, the predominant failure mode under physiologic loading is femoral head rotation about the lag screw axis — not simply varus collapse — and an integrated dual screw nail design provides significantly greater rotational control and is more forgiving when lag screw placement is imperfect (TAD >25 mm).
For single lag screw constructs, nail position on the lateral view matters: even a slightly anterior or posterior tip within an acceptable TAD correlates with increased rotational failure risk.