PathFinder for Minimally Invasive Pedicle Screw Fixation

Overview
To evaluate operative and post operative variables in order to determine if a minimally invasive pedicle screw systems (PathFinder) results in better patient and surgical outcomes, compared to the traditional method of pedicle screw insertion, (InCompass).

Why have you been asked to take part in this research study?
Your doctor has determined that you have a condition called degenerative disc disease, and that you might benefit from a surgical procedure involving placing bone screws, (pedicle screws) into your spine to stabilize it. In this procedure, an intervertebral disc, (the cushion between the bones in your back) is removed from your lumbar  (lower) spine and replaced with a mechanical spacer that acts as a fusion device, (assists in growing bone from one vertebrae (bone in your back) to the other.)  Screws are also placed into the back of the spine and connected with rods to provide additional stability to the spine. The instrumentation is intended to stabilize your vertebrae until fusion can take place. The evaluation will capture clinical, surgical and economic information regarding the use of the screw devices. Two screw systems will be used in this evaluation, PathFinder and InCompass. Both screw systems are distributed by Spinal Concepts, an Abbott Laboratories Company.

PathFinder screw system is placed into your back in a minimally invasive manner. The muscle of your back is opened to reveal the bone into which the screws are implanted.

InCompass screw system is placed into your back in a traditional manner.  Your back muscles are pulled aside providing the surgeon direct visualization of the bones that the screws are placed into.

Who should NOT be in the research study?
Your surgeon will identify potential patients eligible for the study from those seeking his treatment. You should not participate in this study if any of the following apply to you:

• Pregnant or planning to become pregnant during the course of the study.
• Is a prisoner.
• Active infection.
• Failed instrumented fusion at the involved level(s).
• Currently implanted with a posterior lumbar system.
• Currently or previously involved in spinal surgery litigation against a health care provider.
• Metabolic bone disease (Ex. Osteomalacia, Paget’s disease…).
• Condition requiring postoperative medications that may interfere with bony/soft tissue healing.
• Has a disease process that would preclude accurate evaluation (e.g. neuromuscular disease, psychiatric disease, fibromyalgia, etc).
• Morbid obesity, as defined by a patient body mass index greater than 40 (weight (lbs) x 704/height (in2)).
• Has a concurrent disease process that would place the patient in excessive risk to surgery (e.g. late stage cardiovascular or renal disease).
• Any calcification of the great vessels (anterior implantation only).
• Any great vessel disease, (anterior implantation only).
• Active Malignancy.
• Candidate for bone stimulator.
• History of steroid use.

Who is conducting this research study?
This research is sponsored by Spinal Concepts.

How many people will take part in this study?
We propose to close the enrollment period on December 31, 2004.  No less than 5 and no more than 10 sites will contribute patients to this study.  Clinical sites will be expected to identify and enroll 4 patients/month.  Follow-up will continue for a period of 24 months post op.

What is involved in this research study?
Patients in this evaluation will be divided into one of two groups.  Patients in Group 1 will receive the PathFinder screw system in addition to the mechanical spacer in the intervertebral space, while patients in Group 2 will receive the InCompass screw system in addition to the mechanical spacer in the intervertebral space.  The mechanical spacer may be placed into one or two of your intervertebral disc spaces.  Your surgeon will place this device into your disc space through one of 2 approaches, either through your abdomen or through your back.

You will be randomly assigned to receive one of these two screw systems, PathFinder or InCompass.  Your doctor does not know ahead of time which system you will receive.  If you agree to participate in the evaluation, you will need to sign this consent form.  After you have signed this consent form, your doctor will open an envelope containing information identifying which screw system you will receive.  You will not be told which pedicle screw system you will receive until after your 2 year follow up visit so that your opinions collected at follow up visits are not influenced and biased.

You will be admitted to the hospital.  You will undergo the routine tests and procedures for back surgery.  Your surgeon(s) will explain these procedures to you.  Your surgeon(s) will perform your back surgery and take care of you throughout your surgery and convalescence.  The length of time in the hospital, the type of rehabilitation, and the number and type of follow-up visits will be the same as you could anticipate with any back surgery for your disease.

How long will I be in the study?
You will see your doctor for follow-up visits at the following times after surgery: less than 1 month, 3 months, 6 months, 12 months, and 24 months.  At each of these visits your doctor will examine you and x-rays will be taken.  You will also be asked to complete questionnaires about your pain, function, and general health.

What are the risks and discomforts of the study?
As with any general surgery, there are risks of complications from anesthesia, infection, hematoma (a collection of blood under the skin), hemorrhage (bleeding), and death.  Some possible risks associated with posterior spinal surgery, (from the back) are dural leak (a tear or hole in the lining of your spinal sack), complete or incomplete paralysis (inability to move parts or all of your body), loss of feeling in the legs, loss of bowel and/or bladder control, failure of bone to grow (fuse) across the vertebrae, and scarring of the ends of the nerves which may cause numbness, tingling or pain.  Some possible risks from anterior spine surgery (through the abdomen) are: retrograde ejaculation (males only), damage to anatomic structures that carry blood, blood clots, short term paralysis of the bowels.

Use of either screw system may involve risks such as, damage to a nerve causing leg pain, fracture of a part of the vertebrae, soft tissue irritation, movement of the implant from its original position in the spine, and pressing of the device on the spinal cord causing pain and/or loss of function.  There is the risk of an allergic reaction to the metal of the screws.

Your surgeon(s) are experienced in this type of surgery, but the results of this surgery cannot be guaranteed.  One additional risk to you is the possibility that the surgery may not be effective.  There is some element of this risk in all surgeries.  The list of risks may not be complete and it is understood that any or all risks are possible.  You will experience some discomfort associated with your back surgery and the necessary rehabilitation.

Are there any reproductive risks?
For women of child bearing potential:

• I understand that this (treatment/drug) may have and adverse reaction on an unborn child and should therefore not be given during pregnancy.  It may be necessary that a serum pregnancy test (identify type of test here) be done first.  To my knowledge, I am not pregnant at this time.  If I become pregnant during the course of the study, I will immediately notify the investigator and I will be withdrawn from the study.
• If I am a woman of child-bearing potential, I will not participate in this study unless, with the investigator’s knowledge and approval, I am employing a form of birth control approved by Dr. Tobler, the prinicipal investigator directing this study.  I agree to inform the investigator immediately if 1) I have any reason to suspect pregnancy; 2) if I find that the circumstances change and that there is now a risk of becoming pregnant; or 3) I stop using an approved form of birth control.

For sexually active men:

Are there any benefits in taking part in this research study?
The potential benefit to you from the procedure is immediate restoration of the space between your vertebra and perhaps more immediate relief of your symptoms, compared to the alternative treatments available to you should you choose not to participate.  Other potential benefits include stabilization of the spine as an aid to bone fusion, reduction in pain and an increase in function.

What other choices for care are there?
Your alternatives at this time depend upon your condition.  These may include any of the following: physical therapy, traction, body casting, bracing, medications, non-instrumented surgical procedures, instrumentation with a different fusion device or spinal system, or doing nothing.  You may also be implanted with these same screw systems without having to participate in the evaluation.  You and your doctor must decide what is best for you.

What are the costs of being in this study?
There are no costs to the patient.

What compensation is available in case of injury?
The Christ Hospital follows a policy of making all decisions concerning compensation and medical treatment for injuries occurring during, or caused by participation in, biomedical or behavioral research on an individual basis.  If I believe I have been injured as a result of this research, I will contact Dr. William Tobler, 513-569-5281.

What are your rights as a participant?
You may choose either to take part or not to take part in this research study.  If you decide to take part, you may decide to leave the study at any time.

Any questions that I may have concerning any aspect of this investigation or my rights, as a subject will be answered by Dr. William Tobler, 513-569-5281 or Dr. Bohinski or Dr. Kuntz.  I may also contact Debbie Christie at The Christ Hospital Department of Social Services (513-585-2824) to discuss my rights as a research subject.  If I have any medical questions pertaining to this study, I should contact my study physician.  I understand that the appropriate confidentiality will be maintained for all records but that the Food and Drug Administration, Department of Health and Human Services, the study sponsor, and the IRB may inspect the records.

The right to withdraw
I understand that my participation is voluntary and I am free to withdraw from this investigation at any time. Should I wish to withdraw, I have been assured that standard therapy for my condition will remain available to me.  Also, my refusal to participate will involve no penalty or loss of benefits to which I may be entitled.  I have been informed of the probable consequences of my withdrawal from the study.

By agreeing to participate in this evaluation, you are agreeing to return for follow-up visits until the evaluation is complete.  You are not required to give your response(s) for withdrawing from the evaluation.  However, if you decide to withdraw for any reason, at any time, you may do so without fear of jeopardizing your care or your relationship with your doctor.  Your doctor will provide you with any new information he may learn during the course of the evaluation that may influence your continued participation.  Your participation in the evaluation may be discontinued without your consent if you fail to comply with the evaluation procedures.

You have the right to end this Authorization by withdrawing it, at anytime, in writing. Your withdrawal must be made in writing and sent to:

Principal Investigator
William D. Tobler, M.D.
2123 Auburn Avenue Suite #441
Cincinnati, Ohio  45219

How will my personal medical information be kept confidential?
Research study records that identify you will be kept confidential as required by law.  Federal Privacy Regulations provide safeguards for privacy, security and authorized access.

If you choose to be a part of this evaluation you will be assigned an identification number.  This identification number will be used on all data forms and any correspondence between your doctor’s office and anyone connected with this evaluation.  The doctor or a member of the clinic staff will keep the identification number, your name, birth date, and contact information in a file.  No one from outside of the clinic will have access to any private confidential information.  A member of the clinic staff or the doctor may need to contact you during the course of the evaluation.  Your medical records pertaining to this study may be reviewed by the sponsor of the study (Spinal Concepts), agents of the sponsor, the Food and Drug Administration, and/or other public agencies.  In the event that information related to this study is published, you will not be identified in any way.  By signing this informed consent, you consent to such inspection and disclosure.  The doctor or clinic staff will maintain confidential personal information.

You may revoke your privacy authorization at any time, however data that has already been collected may be used for study purposes.

Who to call if you have any questions or problems?
If you have questions about this research study or to report a research-related injury, you can contact the researcher Dr. William Tobler at 513-569-5281.

If you have general questions about giving consent or your rights as a research participant in this research study, you can contact The Christ Hospital Institutional Review Board at 2139 Auburn Avenue, Cincinnati, Ohio 45219.

Location & contact
William Tobler, MD (Principal Investigator)
Charles Kuntz, MD (Co-Investigator)
Robert Bohinski, MD (Co-Investigator)

The Christ Hospital & Mayfield Clinic
Telephone: 513-569-5281
Email: sbasham@mayfieldclinic.com (study coordinator)

More information
Understanding clinical trials