The Pre-Loaded Set-Screw in InterTAN Nail: Should It Be Tightened or Not Tightened in Pertrochanteric Hip Fractures

BACKGROUND: InterTAN is a specific type of cephalomedullary nail with a twin interlocking de-rotation and compression screw, which has inherent ability of anti-rotation. Whether to tighten or not to tighten the preloaded setscrew to allow or not allow secondary sliding in InterTan nail is controversial in clinical practice. METHODS: We retrospectively collected 4 nonunion cases of unstable pertrochanteric femur fractures (AO/OTA-31A2), all were treated with InterTan nail and the preloaded setscrew was tightened in order to prevent further secondary sliding and femoral neck shortening. RESULTS: After 6 months to 2 years follow-up, the fractures showed nonunion in radiography and the patients complained slight to middle degrees of pain, and had to use walking stick assistant in activities of daily life. Tightening the pre-loaded setscrew to prevent postoperative secondary sliding as static constructs might keep the femoral neck length, but lose the opportunity of telescoping for fracture impaction, and take the risk of healing complications, such as fracture nonunion, femoral head cutout or nail breakage. CONCLUSIONS: As the harm outweighs benefit, we advocate the preloaded setscrew in InterTan nail should not be tightened in standard-obliquity pertrochanteric hip fractures (AO/OTA-31A1 and A2).