MESA Rail™ AIS Study - Preservation of Curve Correction

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

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).

Study Overview

• Status: Terminated
• Conditions: Adolescent Idiopathic Scoliosis
• Intervention / Treatment: Device: MESA Rail™ Deformity System

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 188

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 11 years to 21 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Two-hundred four (204) total subjects with the MESA Rail Deformity System at up to 18 clinical sites, geographically distributed worldwide.

Description

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).

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

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

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: K2M, Inc.

Publications and helpful links

General Publications

• Wattenbarger JM, Richards BS, Herring JA. A comparison of single-rod instrumentation with double-rod instrumentation in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2000 Jul 1;25(13):1680-8. doi: 10.1097/00007632-200007010-00011.
• Newton PO, Yaszay B, Upasani VV, Pawelek JB, Bastrom TP, Lenke LG, Lowe T, Crawford A, Betz R, Lonner B; Harms Study Group. Preservation of thoracic kyphosis is critical to maintain lumbar lordosis in the surgical treatment of adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2010 Jun 15;35(14):1365-70. doi: 10.1097/BRS.0b013e3181dccd63.
• Kim YJ, Lenke LG, Bridwell KH, Kim J, Cho SK, Cheh G, Yoon J. Proximal junctional kyphosis in adolescent idiopathic scoliosis after 3 different types of posterior segmental spinal instrumentation and fusions: incidence and risk factor analysis of 410 cases. Spine (Phila Pa 1976). 2007 Nov 15;32(24):2731-8. doi: 10.1097/BRS.0b013e31815a7ead.

Study record dates

Study Major Dates

• Study Start: May 1, 2014
• Primary Completion (Actual): February 23, 2020
• Study Completion (Actual): February 23, 2020

Study Registration Dates

• First Submitted: January 31, 2014
• First Submitted That Met QC Criteria: February 12, 2014
• First Posted (Estimate): February 13, 2014

Study Record Updates

• Last Update Posted (Actual): April 12, 2021
• Last Update Submitted That Met QC Criteria: April 7, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Keywords: Scoliosis; Spinal Diseases; Adolescent Idiopathic Scoliosis; Spinal Deformity; Spinal Curvatures
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Spinal Diseases; Bone Diseases; Spinal Curvatures; Scoliosis
• Other Study ID Numbers: CA-001