2008projectindex101Sucato

Medical Student Research Fellowship for Summer 2007

Mentor: Daniel J. Sucato, MD MS
Department: Orthopaedics
Room number: TSRH, 2222 Welborn Street, Dallas, TX 75219
Mail Code:
Phone number: 214-559-8471
E-mail: dan.sucato@tsrh.org (tara.kristof@tsrh.org -Summer student coordinator)
Project title: Long Term Follow up of Surgically Treated Congenital Spine Deformities

Human subjects IRB approved project number (where applicable): currently submitting, no IRB number yet

Animal subjects IRB approved project number (where applicable): n/a

Project Type (patient-based research, animal-based research, or basic research; this characterization is only to permit a general classification for grouping similar types of projects): Retrospective chart& x-ray review-patient

Brief Description of Project: The student will review each patient's medical chart and will record a variety of important parameters including demographic data, age at surgery, type of surgical procedure, complications and overall functional outcome. The radiographic analysis will start with an evaluation of the preoperative radiographs to determine the type of congenital spinal abnormality and the degree of spine deformity. The postoperative and final radiographs will then be measured and evaluated to determine the overall correction of the deformity. A comparison of the preoperative radiographs and the final radiographs will be performed. Parameters leading to a good radiographic and functional outcome will be determined.

Principal Investigator: Daniel J. Sucato, MD MS
Study Title: Long Term Follow Up of Surgically Treated Congenital Spine Deformities
Sponsor/Funding Source: Texas Scottish Rite Hospital

Purpose: To retrospectively examine the long-term clinical, radiographic and functional outcomes following surgical treatment of congenital scoliosis, kyphosis or kyphoscoliosis.

Background: Congenital spine deformities are relatively uncommon deformities and have significant variation ranging from a single wedge shaped hemi-vertebra to multiples vertebral deformities associated with rib fusions. Progression of the spinal deformity is determined by the type, number and location of the vertebral anomalies although accurate determination of progression is elusive. Similarly, treatment of these deformities varies with age, type of deformity, extent of the deformity and preferences of the surgeon. Many of the patients present at a very young age making appropriate treatment a challenge.

Significant research has been done regarding these patients. One of the earliest series was reported by Winter reviewing 243 congenital scoliosis patients, of which 66 were treated surgically with adequate follow-up. They found that most congenital curvatures are relentlessly progressive and will need treatment and require close supervision. Most patients went on to fusion at an average age of 12 years with overall improvement in the curve correction although stiffness of the deformity prevented significant correction. The natural history of untreated curves resulted in "an unacceptable deformity" and compromised cardiopulmonary function[1, 2]. Until the advent of the Harrington rod there were few articles on operative treatment of congenital scoliosis. Hall et al compared an older group of adolescent patients treated with Harrington instrumentation to a younger group who received non-instrumented correction and postoperative cast. They demonstrated that the patients who had non-instrumented fusions had 5° of correction compared to 22° in the instrumented group; however at follow-up all maintained their correction without radiographic evidence of pseudoarthrosis[3]. In pre-adolescent patients variations of arthrodesis without instrumentation were used for approximately twenty years.[4] In the adolescent population both Harrington instrumentation and fusion without instrumentation were used.[5] As instrumentation and techniques have improved it is now possible to safely instrument and significantly correct the more challenging deformities in both the adolescent and early onset patients.

Congenital spinal deformity can be associated with neural axis abnormalities and are also more likely to have spinal cord monitoring changes and/or neurologic deficits following surgical treatment, which has been traditionally been thought to be more common with spinal instrumentation. The safety and efficacy of such instrumentation was recently examined by Hedequist et al in 2003 and found to be safe while improving and maintaining curvature correction, producing a solid arthrodesis without neurologic compromise in this series[6]. Ayvas et al in 2007 reviewed patients with a corresponding spinal dysraphism and demonstrated a complication rate of 31% with two cases of neurologic deficits both of which resolved. The authors concluded that neurophysiologic monitoring is necessary during all such cases and that early intervention with instrumentation is the optimal choice [7]. Several authors have reported case series in which surgical treatment of congenital spine deformities was performed. [8, 9][10-13].

McMaster et al reported a series of 65 patients treated for congenital kyphosis and kyphoscoliosis at age 9.5 years from 1965 to 1996 with an average length of follow-up of 6.6 years. They found that a posterior spinal arthrodesis prior to 5 years of age was effective in reducing the deformity and maintaining correction secondary to residual anterior growth. They recommended adding an anterior fusion with a rib strut graft to those patients who were older than 5 years with kyphosis greater than 60°. They concluded that kyphotic deformities less than 50° prior in patients younger than 5 years of age should be treated with a posterior procedure alone, while deformity less than 50° on a supine radiograph requires an anterior release with strut graft and posterior spine fusion[14].

While many studies have identified the natural history of this condition or examined a specific technique or safety of surgery there are no studies with long term postoperative follow-up in these patients and there are no studies comparing treatment techniques.

Concise Summary of Project: We propose a study of all patients with congenital spine deformities treated with a surgical procedure with a minimum of 5 years or more of postoperative follow-up. We aim to compare initial surgical correction and maintenance of correction between different techniques and types of deformity. We will also assess for long term complication rates.

We anticipate the numbers on this study to be small due to the length of follow-up. We also anticipate an increase of correction especially in younger patients and in those patients who received instrumentation and more advanced techniques. We also expect to see better maintenance of these techniques over the long term.

Criteria for Inclusion of Subjects: All patients with congenital spine deformities treated with a surgical procedure with a minimum of 5 years or more of postoperative follow-up.

Criteria for Exclusion of Subjects: Any patient who does not meet the inclusion criteria.

Sources of Research Material: This will be a retrospective chart and radiographic review. Clinical data will include demographic data, serial height and weights, age at surgery, length of follow-up, co-existing morbidities, MRI of spine results if available, presence of spinal dysraphism, neurosurgical intervention if necessary, deformity correction surgical technique, operative time, blood loss, intra-operative complications, intra-operative neuro-physiologic monitoring, changes in monitoring, postoperative complications and subsequent spinal surgeries.

Radiographs will be examined preoperatively, immediate postoperatively, 2 years, and at a minimum of 5 years. This data will include description and location of congenital vertebra, major Cobb angles coronally and sagittally, coronal and sagittal balance, and skeletal maturity. Exclusion criteria will be any patient with less than 5 years of follow-up or any patient who is not skeletally mature.

Recruitment Methods and Consenting Process: There is no active recruitment and consent as this is a retrospective chart and radiographic review only. Eligible patients will be selected from a search of the medical records of those patients meeting the inclusion criteria. The investigators will review medical records and x-rays.

Potential Risks: There are no risks specific to this study except potential loss of confidentiality.

Special Precautions: Patient data will be collected and analyzed and will be treated with professional standards.
Procedures to Maintain Confidentiality: Collected data will be maintained by an authorized member of the Orthopaedic Research Staff. All data will be kept in locked files and/or password protected electronic files, and will be used for research purposes only. No patient information will be disclosed outside the study team. The University of Texas Southwestern Medical Center Institutional Review Board may review the research information for auditing purposes.
Patient identifiers will be retained through completion of study, and until such time as all scientific reviews and publications have been finalized; at which time direct linkages to patient identifiers will be destroyed by shredding the document or by deleting electronic files.

Potential Benefits: Congenital spinal deformity is a large part of our patient population and we have an opportunity to review a large series of patients. Based on a query through the medical records department, it appears that 243 cases of congenital spinal deformity have undergone surgical intervention since 1980. These patients are extremely challenging due both to their spinal deformities as well as their young age at presentation. Kyphotic patients are even more challenging due to the potential for spinal cord deficits so that trends in surgical technique, implants, making surgery safer and more effective will improve the treatment of these patients.

Biostatistics: Descriptive statistics will be performed concerning the demographic, clinical and radiographic data. Standard statistical methods will be utilized using the student's t-test to compare preoperative and postoperative radiographs with respect to spine deformity correction. Statistical significance will be defined as p<0.05.

References:
1. Winter, R.B., Congenital Scoliosis A Study of 234 Patients Treated and Untreated: Part 1: Natural History. JBJS, 1968. 50(1): p. 1-15.
2. Winter, R.B., Congenital Scoliosis A Study of 234 Patients Treated and Untreated: Part II: Treatment. JBJS, 1968. 50(1): p. 15-47.
3. Hall, J.E., W.A. Herndon, and C.R. Levine, Surgical treatment of congenital scoliosis with or without Harrington instrumentation. The Journal of bone and joint surgery. American volume., 1981. 63(4): p. 608-619.
4. Winter, R.B., J.H. Moe, and J.E. Lonstein, Posterior spinal arthrodesis for congenital scoliosis. An analysis of the cases of two hundred and ninety patients, five to nineteen years old. J Bone Joint Surg Am, 1984. 66(8): p. 1188-97.
5. Winter, R.B. and J.H. Moe, The results of spinal arthrodesis for congenital spinal deformity in patients younger than five years old. J Bone Joint Surg Am, 1982. 64(3): p. 419-32.
6. Hedequist, D.J., J.E. Hall, and J.B. Emans, The safety and efficacy of spinal instrumentation in children with congenital spine deformities. Spine, 2004. 29(18 (Electronic)): p. 2081.
7. Ayvaz, M., et al., Safety and efficacy of posterior instrumentation for patients with congenital scoliosis and spinal dysraphism. J Pediatr Orthop, 2007. 27(4): p. 380-6.
8. Hedequist, D. and J. Emans, Congenital scoliosis: a review and update. J Pediatr Orthop, 2007. 27(1): p. 106-16.
9. Hedequist, D.J., Surgical treatment of congenital scoliosis. Orthop Clin North Am, 2007. 38(4): p. 497-509, vi.
10. Ruf, M. and J. Harms, Hemivertebra resection by a posterior approach: innovative operative technique and first results. Spine, 2002. 27(10): p. 1116-23.
11. Nakamura, H., et al., Single-stage excision of hemivertebrae via the posterior approach alone for congenital spine deformity: follow-up period longer than ten years. Spine, 2002. 27(1 (Electronic)): p. 110-115.
12. Hedequist, D.J., J.E. Hall, and J.B. Emans, Hemivertebra excision in children via simultaneous anterior and posterior exposures. Journal Of Pediatric Orthopedics, 2005. 25(1): p. 60-63.
13. Ginsburg, G., D.S. Mulconrey, and J. Browdy, Transpedicular hemiepiphysiodesis and posterior instrumentation as a treatment for congenital scoliosis. J Pediatr Orthop, 2007. 27(4): p. 387-91.
14. McMaster, M.J. and H. Singh, The surgical management of congenital kyphosis and kyphoscoliosis. Spine, 2001. 26(19 (Print)): p. 2146.