The goal of this clinical trial is to compare outcomes in the treatment of proximal femur fractures. The main question it aims to answer is whether the use of a double cephalic screw prevents nail failure (cut-out).

Participants will be treated using open reduction and internal fixation with a proximal femoral nail. Researchers will compare intramedullary nailing with a single cephalic screw (Gamma nail) and with a double cephalic screw (Chimaera nail) to see the cut-out rate.

Randomized, open and prospective clinical trial.

Following the surgical indication for open reduction and internal fixation as treatment for proximal femoral fractures, patients will be randomly assigned (ratio 1:1) to one of the following treatments:

Control group: a Gamma 3 nail (single cephalic screw system) will be used for osteosynthesis of the fracture.

Experimental group: a Chimaera nail (system with double cephalic screw) will be used for osteosynthesis of the fracture.

Patient (or their legal guardian) must provide/sign the informed consent prior to inclusion in the study.

After the surgery, patients will be followed-up at 6 weeks, 3 and 6 months. At those times, data related to the radiological examination, the appearance of complications and the walking ability evaluation scale (FAC) will be collected.

Inclusion Criteria:

• Patients with proximal femur fracture (OTA/AO 31-A1, A2 and A3) requiring surgical treatment.
• Signing of written informed consent according to current legislation before collecting any information, either by the patient or by the legal representative or by people linked by family ties.

Exclusion Criteria:

• Presence of other fractures in the ipsilateral femur that condition the surgical treatment of the pertrochanteric femur fracture.
• Subcapital fracture of the proximal femur.
• Subtrochanteric fracture of the proximal femur.
• Pathological fracture.