Medical Student Research Fellowship for Summer 2008

Mentor: Michael J Bolesta, MD
Department: Orthopaedic Surgery
Room number: WA4.328
Mail Code: 8883
Phone number: 214-645-3348
E-mail: michael.bolesta@utsouthwestern.edu
Project I title: Clinical and Radiographic Analysis of PEEK/ChronOS Implants

Human subjects IRB approved project number (where applicable): 082007-027

Animal subjects IRB approved project number (where applicable): na

Project Type: patient based

Brief Description of Project:
PURPOSE: The purpose of this study is to review our results of using PEEK and ChronOs composite implants combined with bone marrow transplant contained within the ChronOs component.
BACKGROUND: Anterior cervical diskectomy and fusion (ACDF) is an operation with a high success rate in relieving upper extremity symptoms, including pain, sensory disturbance and weakness due to nerve root or spinal cord compression. Historically the majority of spinal surgeons fill in the resulting gap with the bone taken from the patient's pelvis. The intent is to stimulate bony union between the vertebrae, fibrous soft tissue forms I 3 to 15% of people. The rate varies depending on the person's age, the number of bones fused, tobacco and medication use. At least 10% of these nonunions are painful enough to prompt additional surgery. Even if the fusion is successful, up to 33 % of patients experience persistent pain at the pelvic donor site. This has prompted research into alternatives to use of the pelvic bone graft. One of those approaches is the use of PEEK (a donut shaped plastic spacer made of polyethyletherketone), ChronOs (beta-tricalcium phosphate, a porous ceramic similar to bone that fits inside the PEEK), and bone marrow transplant (bone forming cells removed from the pelvis with a needle and placed inside the ChronOs). This technology has been used for several years, but has not been critically assessed for effectiveness.
CONCISE SUMMARY OF PROJECT: Patients who have had one to two levels ACDF using PEEK, ChronOs, and pelvic bone marrow transplant at least twelve months ago by one of the investigators will be identified. They will be contacted by telephone or mail for recruitment to the study. The SF-36 general health questionnaire and the NDI (neck disability index, specific to cervical problems) will be given to those who agree to participate. Each subject will be asked to return for examination and standard radiographs if they have not been seen at least 12 months after surgery. The radiographs (anteroposterior and lateral) will be blindly reviewed (deidentified) by two surgeons who did not perform the operation and by a radiologist. Each will be rated as bony fusion, fibrous union, or indeterminate. To be called a bony fusion, all implant interfaces must be intact and there cannot be implant failure. A fibrous union will be defined as lucencies about implants, implant failures, or collapse into kyphosis.

Student Role: The student will meet with administrative personnel to query departmental databases to identify the patients and identify those meeting the inclusion criteria. The student will use this information to review clinic records, ascertaining those who will need additional outcomes and radiographic data. He will help transfer deidentiified data to the database that will ultimately go to the statistician. It is anticipated that the student will also learn to read radiographs and contribute his readings to the data set. He will be encouraged to participate in writing up the report after statistical analysis.

Project II title: Treatment of Ankylosing Spondylitis at the Parkland Health and Hospital System: A Retrospective Review

Human subjects IRB approved project number (where applicable): pending

Animal subjects IRB approved project number (where applicable): na

Project Type patient-based research

Brief Description of Project:

Project Summary: This study will consist of a retrospective chart review of available AS patients who were treated at Parkland for trauma to the spinal column to assess their general and neurological conditions following treatment.

Criteria for Inclusion of Subjects: Subjects must have been diagnosed with AS, must have later on suffered trauma to the spinal column, and must have been treated either surgically or conservatively at Parkland Memorial Hospital. Subjects may be either adult male or female, and of any racial or ethnic group.

Criteria for Exclusion of Subjects: Subjects lacking adequate chart documentation of AS, spinal trauma, and neurological status upon presentation and throughout follow-up.

Sources of Research Material: Charts of patients with ankylosing spondylitis. The study will utilize existing information. Patients will not come into contact with the investigators as part of the study, and we are requesting a waiver of subject consent.

Recruitment of Subjects: There is no recruitment for this study. This study is a retrospective review of already existing data.

Potential Risks: There are no foreseeable risks to patients as this is a retrospective study using existing materials. There is a minimal risk with respect to loss of patient confidentiality however; the PI will provide every effort to keep all patient's information confidential.

Special Precautions: There will be no special precautions for this study. The Institutional Review Board for UT Southwestern Medical Center may review study data at any time to ensure this study is carried out in compliance with all local, state, and federal guidelines. Such an IRB review could encompass all study data.

Procedures to Maintain Confidentiality: Personal identifiers on the charts will not be entered into the database. Each subject from the data collection sheet will be assigned a unique, non-traceable identification number that will be used in the database. A key will be made that contains the patient's name, MRN and the identification number assigned for use in the database. The key will be used to assure that the measurements taken are properly entered and grouped into the database for analysis. The key will be secured in a locked cabinet in Dr. Bolesta's office. It will be available to the investigators during the chart-reading sessions and secured at all other times. The key will be destroyed after the final data set is complete. Only the database, which lacks personal identifiers, will be used for the statistical analysis. Images produced for presentation and publication will be stripped of identifiers. The measurements will take place at a secure location.

Potential Benefits: There are no potential benefits to the subject. However, evaluating the outcomes of conservative vs. surgical treatment of Parkland AS patients who suffered trauma will provide surgeons with more information on which to base decisions of how to treat such patients in the future.

References:
1. Alaranta H, Luoto S, Konttinen YT. Traumatic spinal cord injury as a complication to ankylosing spondylitis. An extended report. Clin Exp Rheumatol. 20:66, 2002.
2. Hunter T, Dubo H. Spinal fractures complicating ankylosing spondylitis. Ann Intern Med. 88:546-549, 1978.
3. Schroder J, Liljenqvist U, Greiner C, Wassmann H. Complications of halo treatment for cervical spine injuries in patients with ankylosing spondylitis-report of three cases. Arch Orthop Trauma Surg. 123:112-114, 2003.
4. Sciubba DM, Nelson C, Hsieh P, Gokaslan ZL, Ondra S, Bydon A. Perioperative challenges in the surgical management of ankylosing spondylitis. Neurosurg Focus. 24 (1):E10, 2008.
5. Hitchon PW, From AM, Brenton MD, Glaser JA, Torner JC. Fractures of the thoracolumbar spine complicating ankylosing spondylitis. J Neurosurg. 97 (2 Suppl):218-222, 2002.
6. Weinstein PR, Karpmann RR, Gall EP, Pitt M. Spinal cord injury, spinal fracture, and spinal stenosis in ankylosing sponylitis. J Neurosurg. 57:609-616, 1982.

Student role: under guidance of mentor, Michael Mathews will query Parkland Trauma Registry to identify study subject, pull appropriate charts and abstract the pertinent data, recording it in a secure database.