Pertrochanteric Fracture Fixation In Elderly Adults Using Proximal Femoral Nail Anti-rotation (HERACLES) With a T-shaped Parallel Blade: A New Design

Not Applicable

• Conditions: Pertrochanteric Fracture of Femur, Closed; Pertrochanteric Fracture; Intertrochanteric Fractures; Pertrochanteric Fracture of Femur, Open
• Interventions: Device: Proximal femoral nail with straight parallel blade

• Registration Number: NCT03911180
• Lead Sponsor: Ilocos Training and Regional Medical Center

Brief Summary

This is a prospective case series of elderly adult patients sustaining pertrochanteric fractures who will be treated by a proximal femoral nail with a non-helical (straight) blade. This study seeks to observe and evaluate the outcomes, advantages and complication rates in using the HERACLES PFN with a non-helical (T-shaped parallel) blade.

Detailed Description

The trochanteric area is defined by AO as the area bordered by the tip of the greater trochanter, extracapsular portion of the femoral neck extending to a line parallel to the inferior most border of the lesser trochanter.

Pertrochanteric fracture is a fracture is of the trochanteric area which is usually reducible. Unstable pertrochanteric fracture is defined as AO-31A2 or AO-31A3. Instability arises from the degree of comminution, the presence, and comminution of the posteromedial fragment and lastly, lateral wall involvement The ideal implant for fixation of this kind of fractures is still under debate, but intramedullary implants are preferred than extramedullary implants in these unstable fractures. On the other hand, unique fracture configurations predispose to instability such as reverse obliquity fractures and fractures extending to the subtrochanteric area.

Proximal femoral locking plate as used in unstable pertrochanteric fracture has a high complication rate. In one study in 2014, there is up to 41.4% failure rate due to the proud plate, screw malposition, too rigid construct when used as a bridge plate.

Intramedullary implants specifically cephalomedullary nails has been the mainstay of treatment in unstable pertrochanteric fractures primarily because of the short moment arm and load-sharing properties. It employs relative stability and can be applied in a minimally invasive manner.

In 1997, the AO/ASIF group developed the proximal femoral nail. The proximal femoral nail has two proximal screws that traverse the neck to the femoral head. The inferior screw is the load-bearing screw, and the superior screw is the anti-rotation screw. Good to excellent results were observed using this implant compared to previous implant designs, but complications still exist.

These complications are related to the position of the two screws. There is difficulty attaining the ideal placement of proximal locking screws. As a result, the early medial cutout of one screw and lateral migration of the second screw occurs which is the so-called Z-effect. To address these disadvantages, the AO/ASIF group in 2004 developed a new implant design wherein the two proximal locking screws are replaced by a single helical blade. This improvement in design maximizes bone purchase and bone contact in cancellous bone hereby improving cutout rates.

Even with the new PFNA implant is not exempted from complications. Zhou and Chang in 2012 identified 12 cases of helical blade protrusion in 6 papers. Biomechanically, the helical blade migrates axially through the porotic bone in the geriatric population.

The new design of the blade includes a T-shaped anchor for stable fixation in osteoporotic bone. The nail also features a flat lateral design with a smooth radius transition from proximal to distal portion of the nail compared to the bulky profile of conventional nail resulting in easier insertion. Locking mechanism inherent to the nail and blade limits gliding and rotation of the blade. One of the advantages of the system is the use of a radiolucent arm with targeting options for an anti-rotation pin and determination of the superior most aspect of the femoral head for reference.

This case-series introduces a modification in implant design of the PFNA and aims to observe outcomes, advantages, and complications related to its use.

Study Timeline

• Status Verified: 2019-04
• Study First Submitted: 2019-04-06
• Study First Submitted QC: 2019-04-09
• Last Update Submitted: 2019-04-09
• Study First Posted: 2019-04-11
• Last Update Posted: 2019-04-11
• Study Start: 2019-05-01
• Primary Completion: 2020-05-01
• Study Completion: 2022-05-01

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

1. Patients who sustained stable pertrochanteric fracture (AO31A.1)
2. Patients who sustained unstable pertrochanteric fracture (AO31A.2 or AO31A.)

Exclusion Criteria

1. Patients who are bedridden
2. Patients with a neurologic/psychiatric disorder (previous or present)
3. Patients with severe dementia/Alzheimer's disease
4. Patient with a history of hip dislocation (whether reduced or unreduced)
5. Patient who underwent previous operation on the hip
6. Patient with amputation of one or both legs
7. Patient with segmental fractures involving the ipsilateral femoral shaft/metaphysis
8. Patient with pathologic fractures, e.g. secondary to metastatic bone disease/ metabolic bone disease
9. Patient presenting with an infection
10. Patient who sustained multiple injuries from other body systems

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
PFN straight parallel blade	Proximal femoral nail with straight parallel blade	All patients with pertrochanteric fracture that is eligible will undergo PFNA with straight parallel blade.

Primary Outcome Measures

Name	Time	Method
Time to Clinical Union	2 months to 4 months	Weeks until Union; Clinical Union - fracture site becomes stable and pain-free
Time to full weightbearing	4-6 months	weeks until full weight bearing without pain

Secondary Outcome Measures

Name	Time	Method
Quality and Maintenance of Reduction	up to 2 years	Acceptable reduction was defined as: 1. Range of neck angle between 5° varus and 20° valgus.; 2. \<20 deg angulation on lateral; 3. No fragment greater than 4 mm displaced; Reduction is defined as good (3/3), adequate (2/3) and poor (0-1/3)
Tip-Apex Distance	up to 2 years	expressed in millimetres, is the sum of the distance from the tip of the blade to the apex of the femoral head on both AP and lateral radiographic views
Blood Loss	Taken immediately postop	Blood loss during the procedure in milliliters
Fluoroscopy time	Intraoperative measurement	Total time of exposure during the procedure starting from identification of starting point to insertion of distal locking screw
Mobility scale	up to 2 years	Mobility scoring modified for use in patients who sustained a hip fracture (Bowers and Parker 2016). 1 is best and 10 is worst.; 1. Never uses any walking aid, no restriction in walking distance; 2. Never uses any walking aid, can walk less than one kilometer; 3. Occasionally uses a walking aid; 4. Normally uses one walking stick or needs to hold on to furniture; 5. Normally uses two sticks or crutches; 6. Mobilizes with a frame alone, without the need for assistance; 7. Mobilizes with a frame and the assistance of one other person; 8. Mobilizes with a frame and the assistance of two people; 9. Bed-to-chair, or wheelchair-bound; 10. Bedbound most or all of the day.
Social dependence scale	up to 2 years	Modified to apply for hip fractures; includes determination of independence to ADLs and advanced ADLs (Bowers and Parker 2016) 1 is best and 8 is worst; 1. Completely independent; 2. Minimal assistance; 3. Moderate assistance; 4. Regular assistance; 5. Dependent; 6. Severely dependent; 7. Fully dependent; 8. Patient temporarily resident in hospital
Pain scale	Postop up to 2 years	Pain scale adapted for hip fractures (Bowers and Parker 2016) 1 is best and 8 is worst; 0. Unable to answer; 1. No pain at all in the hip; 2. Occasional and slight pain; 3. Some pain when starting to walk, no rest pain.; 4. None or minimal pain at rest, some pain with activities; 5. Regular pain with activities which limits walking distance.; 6. Frequent rest pain and pain at night. Pain on walking.; 7. Constant pain presents around the hip.; 8. Constant and severe pain in the hip requires regular strong analgesia such as opiates.
Radiographic Union Score for the Hip	up to 2 years	is a validated outcome instrument designed to improve intra and interobserver reliability when describing the radiographic healing of proximal femur fractures; Based on grading of the anterior cortex, posterior cortex, lateral cortex and medial cortex bridging; 1. - No cortical bridging; 2. - Some cortical bridging; 3. - Complete Cortical Bridging; In addition, disappearance of the fracture line in the anterior cortex, posterior cortex, medial cortex, lateral cortex; 1. - Fully visible fracture line; 2. - Some evidence of the fracture line; 3. - No evidence of fracture line; Add all component scores to get the total score
Radiation load	Intraoperative measurement	Amount of radiation during the procedure as measured by a Dosimeter