MESA Rail™ AIS Study - Preservation of Curve Correction

Study Overview
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Brief Summary
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To evaluate the restoration and maintenance of thoracic kyphosis and coronal curve correction demonstrated through the surgical implantation of the K2M MESA Rail™ Deformity System as compared to literature reported outcomes for standard Cobalt Chrome (CoCr) rod systems in the treatment of Adolescent Idiopathic Scoliosis (AIS).

Detailed Description
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Patients treated with the Ø5.5mm or Ø4.5mm MESA Rail™ Deformity System that had: Diagnosis of AIS requiring surgical treatment for selective non-cervical fusion with a minimum of five (5) instrumented vertebrae between T1-S1 as confirmed by patient history and radiographic studies. AIS cases must be classified as a Lenke type 1 or type 2 curve (lumbar modifiers and thoracic sagittal profiles will be noted but not restrictive). Age at time of surgery of ≥ 11 years old and ≤ 21 years old.

Official Title
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Preservation of Thoracic Kyphosis and Coronal Curve Correction as a Function of Rod Stiffness in the Surgical Treatment of Adolescent Idiopathic Scoliosis (AIS) With the Use of the K2M MESA Rail™ Deformity System

Conditions
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Adolescent Idiopathic Scoliosis

Intervention / Treatment
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* Device: MESA Rail™ Deformity System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of AIS requiring surgical treatment for selective thoracic/lumbar fusion with a minimum of five (5) instrumented vertebrae between T1-S1 as confirmed by patient history and radiographic studies. AIS cases must be classified as a Lenke type 1 or type 2 curve. No cervical vertebrae are to be incorporated into the construct. Willingness and ability to comply with the requirements of the protocol including follow-up requirements. Willing and able to sign a study specific informed consent form or, in the case of a patient who is a minor, provide assent and the minor patient's parent/legal guardian provides written consent to participate. Age range of ≥ 11 years old and ≤ 21 years old at time of surgery. Exclusion Criteria: Previous anterior or posterior spine surgery at the index levels. Previous posterior spine surgery (e.g., posterior element decompression) that destabilizes the cervical/thoracic/lumbar spine. Active systemic infection or infection at the operative site. Co-morbid medical conditions of the spine or upper/lower extremities that may affect the thoracic or lumbar spine neurological and/or pain assessment. Metabolic bone disease such as osteoporosis that contradicts spinal surgery. History of an osteoporotic fracture. History of an endocrine or metabolic disorder (e.g., Paget's disease) known to affect bone and mineral metabolism. Taking medications that may interfere with bony/soft tissue healing including chronic steroid use. Known allergy to titanium or cobalt chrome. Rheumatoid arthritis or other autoimmune disease or a systemic disorder such as HIV, active hepatitis B or C or fibromyalgia. Insulin-dependent type 1 or type 2 diabetes. Medical condition (e.g., unstable cardiac disease, cancer) that may result in patient death or have an effect on outcomes prior to study completion. Pregnant, or intend to become pregnant, during the course of the study. Severe obesity (Body Mass Index > 40).

Ages Eligible for Study
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Minimum Age: 11 Years
Maximum Age: 21 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| AIS<br>Surgical implantation of the K2M MESA Rail™ Deformity System in the treatment of Adolescent Idiopathic Scoliosis (AIS). | Device: MESA Rail™ Deformity System<br>* MESA Rail™ (cross-sectioned rod) with MESA pedicle screws compared to traditional rod use in the literature<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Thoracic Kyphosis and Coronal Curve Correction on X-ray at 24 Months | Restoration and maintenance of thoracic kyphosis and coronal curve correction. Thoracic kyphosis (Coronal Curve): measurement of curvature from the upper endplate of T4 to the lower endplate of T12. | Baseline (up to 90 days before surgery), 24 months | 
| Number of Participants With Adverse Events | Number of participants with SAE and AE for the various intervals | Up to 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Pain Scores on the Visual Analog Scale (VAS) at 24 Months | Evaluation of the improvement of the Back VAS and Hip/Leg VAS (assessed together) at the 24 month post-operative visit as compared to pre-op time periods. Information on all reports of pain/numbness /tingling and the location of symptoms were captured and evaluated. VAS scale ranged from 0 - 100mm with the 100mm accounting for the highest level of pain. | Baseline (up to 90 days before surgery), 24 months | 
| Change From Baseline in Quality of Life Scores on the SRS-22r at 24 Months | The Revised Scoliosis Research Society-22 (SRS-22r) is a specific questionnaire for spine conditions. It is applied to patients with idiopathic scoliosis, whose conditions and treatments have a great impact on their quality of life. The SRS 22r was created and revised with the purpose of evaluating this impact from the patient's point of view. The reviewed version contains 22 questions distributed into five domains: function/activity (FA), pain (P), self- image/appearance (SA), mental health (MH) and satisfaction with treatment (ST). The scores vary from 1 to 5 in which 5 is the best health quality of life of patients. | Baseline (up to 90 days before surgery), 24 months | 
| Patient Satisfaction | At the 12 month and 24 month follow-up visits, subjects were asked whether they were satisfied with the outcome of their surgery (Yes/No) and whether they would repeat the operation (Yes/No). | 12 months and 24 months | 
| Investigator's Rating of Subject's Clinical Disposition Using Odom's Criteria | At the 24 month follow-up visit, the Investigator rated the clinical disposition of each study subject according to Odom's Criteria as follows: Excellent: all pre-operative symptoms relieved, able to carry out daily occupations without impairment. Good: minimum persistence of pre-operative symptoms, able to carry out daily occupations without significant interference. Fair/Satisfactory: relief of some pre-operative symptoms but physical activity is significantly limited. Poor: symptoms or signs unchanged or worsened. | 24 months | 
| Length of Surgery Time | The length of the surgical procedure from the initial incision to final closure were captured. | During surgery | 
| Length of Anesthesia Time | The length of time the patient is under anesthesia was captured. | During surgery | 
| Estimated Blood Loss | The amount of blood loss over the entire length of the surgery was captured. | During surgery | 
| Length of Hospital Stay | The length of the hospital stay from the date of admission to the date of discharge. | Admission to Discharge | 
| Change in Percentage of Participants Able to Return to Work/School | The ability to and the time it takes for the subject to be cleared to return to work/school from the date of surgery by looking at the change in percentage of participants who were able to return to work without any restrictions | Pre-Op to 24 months | 
| Use of Narcotics Post-surgery | The types and dosages of any narcotics taken by the patient pre- and post-surgery was documented. | Pre-Op to 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Scoliosis, Spinal Curvatures, Spinal Diseases, Adolescent Idiopathic Scoliosis, Spinal Deformity