The objective of this study is to compare the failure rate between two modes of fixing the lag screw of the cephalomedullary nail.

The sample studied will be patients who have been diagnosed with a fragility intertrochanteric fracture.

Investigators hypothesis is that the dynamic mode will have a lower failure rate compared to the static mode.

Intertrochanteric fragility fractures are one of the most frequent fractures in the elderly . They produce great disability and complications in our patients and they are recognized worldwide as a major public health problem.

The treatment that presents the best results is surgical treatment, since it reduces the mortality of the patients and allows early loading . Thus, avoids secondary complications to the prostration state such as pneumonia, bedsores, pulmonary embolisms, among others.

Currently, the treatment that has shown the best clinical and biomechanical results is osteosynthesis with a cephalomedullary nail, which despite having good results is not free from complications such as implant failure, loss of femoral offset.

Changes are constantly made in the design and surgical techniques of these implants in order to decrease the rate of complications.

This study will particularly assess whether there is any difference in the complication rate between dynamic versus static lag screw modes.

Biomechanical studies that compare these two lag screw modes show that axial and lateral stiffness of the femur-nail construction is greater in static mode than in dynamic modes and the torsional stiffness is greater in dynamic mode than in static modes.

There are no studies comparing the clinical results of these two variants.

Inclusion Criteria:

• Low Energy Mechanism
• Hip fracture classified as 31.A1.2 - 31 A1.3 and 31.A2 in the AO classification (year 2018)

Exclusion Criteria:

• A fracture due to malignancy
• Previous contralateral fracture
• Inability to walk before the fracture
• An inability to comply with rehabilitation
• Follow-up of less than 6 months