Flex Intramedullary Rod Study

Study Overview
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Brief Summary
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The purpose of this study is to compare the effect of post-operative ROM between Flex IM rod and Rigid IM rod, to collect bone morphology of Japanese lower extremity and to research the incidence of overhung with Flex IM rod.

Official Title
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A Prospective, Post-market, Multi-center Comparative Study of the Efficacy of Flex Intramedullary(IM) Rod in Terms of Range of Motion (ROM) Improvement.

Conditions
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Osteoarthritis of the Knee, Arthroplasty, Replacement, Knee

Intervention / Treatment
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* Device: Flex IM rod


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient has signed an Institutional Review Board (IRB) approved, study specific Informed Patient Consent Form. Patient is a male or non-pregnant female age 20 years or older. Patient is candidate for primary Total Knee Arthroplasty (TKA). Patient whose preoperative range of motion (ROM) is over 110 degree. Patient is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation. Exclusion Criteria: Revision cases Patients that use bone wedges or allograft due to bone loss. Patient has a Body Mass Index (BMI) >40. Patient has an active or suspected latent infection in or about the affected knee joint at time of study device implantation. Patient has a neuromuscular or neurosensory deficiency, which limits the ability to evaluate the safety and efficacy of the device. Patient is diagnosed with a systemic disease (e.g. Lupus Erythematosus) or a metabolic disorder (e.g. Paget's Disease) leading to progressive bone deterioration. Patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements (e.g. > 30 days). Patient has failed unicondylar knee prosthesis. Patient has a known sensitivity to device materials. Patient who are inappropriate for participating in the study in the judgment of the investigator.

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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Flex IM Rod<br> | Device: Flex IM rod<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum postoperative flexion angle |  | 48 weeks after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quality of life as assessed by36-Item Short-Form Health Survey (SF-36)questionnaire |  | 4 weeks , 24 weeks and 48 weeks after surgery | 
| Japanese Knee Osteoarthritis Measure(JKOM) |  | 4 weeks , 24 weeks and 48 weeks after surgery | 
| Knee Society Scale (KSS) |  | 4 weeks , 24 weeks and 48 weeks after surgery | 
| Range of Motion (ROM) |  | 4 weeks , 24 weeks and 48 weeks after surgery |