CM Asia Nail With AS2 Without AS2 （AS2 Study）

Study Overview
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Brief Summary
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The purpose of this study is to compare reduction positon maintenance rate at 3 weeks post-operatively between patients operated with Anterior Support Screw (AS2) and without AS2 technique in RCT setting. Total 240 cases(each arm 120 cases) will be enrolled at maximum 15sites, total study duration is 22months.

Detailed Description
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Objective： To compare fracture reduction maintenance rate at 2-3weeks post-operatively between patients operated with AS2 (investigational group) and patients operated without AS2 (Control group) using same implant system (ZNN CM Asia, Zimmer Biomet). Endpoint： Primary： The rate of reduction position maintenance at 2-3 weeks post-operatively. Secondary： Surgery time / fracture type / postoperative reduction position / CT assessment / Safety information

Official Title
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Randomized Controlled Study Comparing Zimmer Natural Nail System Cephalomedullary Asia Nail With Anterior Support Screw (AS2) Versus Conventional Technique

Conditions
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Trochanteric Fracture of Femur

Intervention / Treatment
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* Procedure: Open Reduction and Internal Fixation
* Device: ZNN CM Asia
* Device: Anterior Support Screw


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: In order to be eligible to participate in this study, a subject must meet all of the following criteria. Eligible for intramedullary nailing. Fracture type is classified as 3-partB or 4-part fracture in 3D-CT (Three Dimensional Computed Tomography) classification (Nakano), and combination with a subtype P in lateral classification (Ikuta) at preoperative CT (Computed Tomography) assessment.(In the case of classified in radiograph (X-ray) at preoperative: Classified as Type 4 or Type 5 in Jensen classification, and combination of subtype P in lateral classification (Ikuta)) Japanese Male or female > 20 years of age Primary closed intertrochanteric fracture of the femur Subjects willing to return for follow-up evaluations. Exclusion Criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study. Patient who cannot take CT image within 3 days and 2-3weeks after surgery. Uncooperative patient or patient with neurologic disorders who are incapable of following directions.

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: At surgery, intervention group using ZNN CM Asia with AS2 technique. At surgery, conventional group using ZNN CM Asia without AS2 technique.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ZNN CM Asia with AS2 technique<br>Open Reduction and Internal Fixation with AS2 Trochanteric Fracture treated by Open Reduction and Internal Fixation using with ZNN CM Asia nail. Bone fragment will be stabilized by additional screw fixation (Anterior Support Screw). | Procedure: Open Reduction and Internal Fixation<br>* Fractured bone fragments are reduced and stabilized by intramedullary nail.<br>Device: ZNN CM Asia<br>* Reduced bone fragments are to be stabilized by Zimmer Natural Nail CM Asia System.<br>Device: Anterior Support Screw<br>* Experimental group will receive insertion of ACE 4.5/5.0mm cannulated lag-screw anteriorly to Zimmer Natural Nail CM Asia Lag-screw.<br>* Other names: ACE 4.5/5.0mm cannulated lag-screw;|
| Active Comparator: ZNN CM Asia without AS2 technique<br>Trochanteric Fracture treated by Open Reduction and Internal Fixation using with ZNN CM Asia nail without additional screw fixation. | Procedure: Open Reduction and Internal Fixation<br>* Fractured bone fragments are reduced and stabilized by intramedullary nail.<br>Device: ZNN CM Asia<br>* Reduced bone fragments are to be stabilized by Zimmer Natural Nail CM Asia System.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Patient With and Without Excessive Lag Screw Sliding Distance | Number of patient was counted based on CT measurement results. Relative position of lag screw between CT images taken at both immediate and 2-3 weeks postoperatively was measured and recorded in value (e.g., 1.5 mm). This was called as lag screw sliding distance. Four millimeter was set as threshold to define success and failure. Less than 4mm of lag screw sliding distance was recognized as Success and equal to or more than 4mm of lag screw sliding distance was recognized as Failure. | Postoperative 2-3 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surgery Time | Surgery time from skin incision to closure | Intraoperative, an average of 1 hour | 
| Image Assessment Using Computed Tomography (CT) | Number of patient was counted based on CT measurement results. When the fracture reduction position achieved at surgery was maintained at 2 to 3 weeks, then the patient was categorized as success (Reduction position maintained). On the other hand, patient was categorized as failure (Reduction position changed) in the case that the fracture reduction position was changed. Fracture repair position was categorized into three; Anterior, Neutral or Posterior based on relative position of proximal bone fragment and distal bone fragment. This analysis only includes patients whose fracture reduction position at immediate postoperative CT was either Anterior or Neutral. If both immediate and 2-3 weeks postoperative CT images show same fracture reduction position (example: Anterior at immediate postoperatively & Anterior at 2-3 weeks postoperatively), then the patient was recognized as Success (Reduction position maintained). | 2-3 weeks postoperatively | 
| Intraoperative Safety | This is to evaluate whether any adverse events specific to insert additional screw for AS2 technique were occurred. | Intraoperative |