Static Helical Screw Locking of Pertrochanteric Femur Fractures Using the TFN-A

Fraser Orthopaedic Research Society

Status: Enrolling

Conditions: Pertrochanteric Fracture

Treatments: Procedure: Dynamic Rotational Locking; Procedure: Static Locking

Study type: Interventional

Funder types: NETWORK; Industry

Identifiers

NCT04851509

FHREB#: 2021-015

Details and patient eligibility

About

The study will investigate the shortening and collapse of pertrochanteric fractures following surgical management with the TFN-Advanced nailing system. The focus will be on comparing radiographic assessments of nails which have been statically locked versus dynamically locked. This is a randomized control study with the initial invention being randomized to either statically locking or dynamically locking. For a two-month period, all eligible patients will receive the randomized allocated treatment, then treatment will switch to the alternate treatment for the next two months and will continue to alternate treatments for two-month periods until study enrollment has completed.

Full description

Hip fractures are common injuries in the elderly population that result in significant morbidity and mortality and a significant burden on health care systems. Hip fractures can be treated with arthroplasty or with internal fixation, depending on the fracture pattern. Cephalomedullary nailing (CMN) has become one of the established treatments for intertrochanteric hip fractures with a wide variety of implant designs from many different companies. The TFN-ADVANCED™ Proximal femoral nailing system (TFN-A) is a novel implant for treating intertrochanteric and subtrochanteric proximal femur fractures with a paucity of published literature on the performance of this implant.

A method to decrease the amount of fracture compression is to use the set screw to lock the screw "statically" so it does not slide to the same degree as if the screw is placed in the "dynamic" or sliding position. To the knowledge of the investigators, the role of statically locking the screw to prevent fracture collapse has not been studied. Statically locking CMN to treat hip fractures has become standard of care at the Royal Columbian Hospital with all the investigating surgeons having adopted this practice in an attempt to prevent significant fracture collapse and neck shortening. Anecdotally, the investigators have not seen significant rates of cephalic screw cut-out over the past five years, and believe the investigators' screw cut-out rates are lower than what is reported in the literature. The investigators have been using the Gamma Nail (Stryker) to statically lock the screw as the previous TFN lacked the ability for static locking. However, with the advent of the TFN-A, the investigators have adopted this implant as their long cephalomedullary nail of choice for fixation of pertrochanteric femur fractures.

Enrollment: 218 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients >18 years of age
• AO/OTA 31-A fractures who the surgeon deems eligible for treatment with a cephalomedullary nail
• Open and closed fractures
• Ambulatory prior to injury (with or without walking aides)
• Native (non-fractured, no implant) contralateral hip
• Willing and able to sign consent (substitute decision maker)

Exclusion criteria

• Contralateral hip fracture or hip arthroplasty
• Fracture not amenable to treatment with a cephalomedullary nail
• Non-ambulatory patient
• Fractures >14 days (time of injury to OR)
• Bilateral pertrochanteric hip fractures
• Non-unions
• Pathologic fractures
• Periprosthetic fractures
• Patients with spinal injury
• Incarceration
• Pregnancy
• Limited life expectancy due to significant medical co-morbidities or medical contra-indications to surgery
• Likely problems, in the judgement of the investigators, with maintaining follow-up (i.e., patients with no fixed address, report a plan to move out of town, or intellectually challenged patients without adequate family support).

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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218 participants in 2 patient groups

Dynamic rotational locking

Active Comparator group

Description:

Using a fracture table, the affected leg will be placed into traction and the patient will be prepped and draped in the usual fashion. The fracture will be provisionally reduced using closed techniques. A 3cm incision will be used to gain access to the intramedullary canal and the nail (either a short nail or long nail, at the discretion of the treating surgeon) will be introduced to the femur. The screw will be placed across the fracture and into the femoral head, aiming for a tip-to-apex distance less than 25mm. The compression nut will be used to compress the fracture. The screw will be rotationally locked by using the 5mm hex flexible screwdriver by advancing the set screw until it stops completely. The screw will then be turned counterclockwise by a ½ turn.

Treatment:

Procedure: Dynamic Rotational Locking

Static locking

Experimental group

Description:

Using a fracture table, the affected leg will be placed into traction and the patient will be prepped and draped in the usual fashion. The fracture will be provisionally reduced using closed techniques. A 3cm incision will be used to gain access to the intramedullary canal and the nail (either a short nail or long nail, at the discretion of the treating surgeon) will be introduced to the femur. The screw will be placed across the fracture and into the femoral head, aiming for a tip-to-apex distance of less than 25mm. The compression nut will be used to compress the fracture. The screw will then be statically locked using the 6Nm torque-limiting blue handle with 6mm hex coupling to completely lock the set screw down on the helical screw.

Treatment:

Procedure: Static Locking