Medical Student Research Fellowship for Summer 2010
Mentor: Daniel J. Sucato, MD MS
Department: Orthopaedics
Room number:
a) Mail Code: TSRH, 2222 Welborn Street, Dallas, TX 75219
Phone number: 214-559-8471
E-mail: Research Coordinator Tara Kristof: tara.kristof@tsrh.org
Project title: Operative Treatment of Scoliosis in Patients with Syringomyelia:
Choosing Fusion Levels and Risk for Curve Progression Postoperatively
Human subjects IRB approved project number (where applicable): not submitted 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): Patient
Brief Description of Project:
PURPOSE: The purpose of this study is to analyze the radiographic results following
surgical treatment for scoliosis in patients with syringomyelia. Specific parameters
to be analyzed are:
1) Fusion levels and their effect on curve correction.
2) Fusion levels and their effect on curve progression postoperatively.
BACKGROUND: Scoliosis is often associated with an underlying syringomyelia. The syringomyelia refers to the tubular cavitation within the spinal cord. A distinction can be made based on whether the cells lining the cavity are composed of ependyma (hydromyelia) or those which are lined with glial cells (syringomyelia). Today however, the lesions are typically characterized as being hydrosyringomyelia and grouped together. These spinal cord cavities or cysts can be divided into two general groups: those that communicate with the cerebrospinal fluid pathways and those that do not. Communicating hydrosyringomyelia is usually associated with Chiari malformations and basilar arachnoiditis. Non-communicating hydrosyringomyelia is usually associated with trauma, intramedullary spinal cord tumors or spinal arachnoiditis. Treatment of syringomyelia is very dependent on size of the lesion, location of the lesion and the clinical sequelae from the syringomyelia. Neurosurgical treatment includes placement of a syringosubarachnoid or syringoperitoneal shunt.
The scoliosis that is associated with syringomyelia is often "atypical" (different from the common idiopathic-type curve) in that the curves are often left-sided thoracic curves, have sagittal plane kyphosis, and are associated with neurologic changes. Several small studies have analyzed the natural history of scoliosis when a syringomyelia is present and it's non-operative management. Studies demonstrate that bracing is not effective in preventing curve progression. Neurologic signs are present in most children and often stabilize after syrinx drainage. The impact of surgical drainage is controversial in that some predict no effect on curve progression, while others feel that it does effect curve progression.
To our knowledge, however, there are no large studies which have analyzed the operative treatment of patients who have syringomyelia and scoliosis. The largest study looking at spinal surgery was recently published by Ferguson et al and consisted of 10 patients who were followed for an average of 46 months and lost 10 degrees of correction either above, through or below the instrumented segments. They suggested that anterior fusion stabilized the patients better than posterior fusion. The clinical experience at Texas Scottish Rite Hospital would suggest that operative treatment is more challenging than the typical adolescent idiopathic scoliosis. Specifically, the levels of fusion and the risk for "adding on" to the upper or lower aspect of the curve as well as risk for further progression of the curve have been seen.
CONCISE SUMMARY OF PROJECT: This will be a retrospective chart and radiographic review conducted of all patients who have been treated at Texas Scottish Rite Hospital for Children with scoliosis and associated syringomyelia. The medical record will be reviewed to identify demographic data (age, gender, race, menarchal status) as well as clinical examination (to include neurologic examination, clinical deformity). The operative record will be reviewed to determine age of surgery, type of instrumentation used, type of approach used (anterior vs. posterior), type of fixation (hooks, screws, or wires), type of bone graft, blood loss, duration of surgery, and type of neurologic monitoring, and any neurologic changes. The medical record would then be used to analyze the postoperative course including whether bracing was used and any complications that occurred (infection, neurologic injury, pseudarthrosis, etc.).
Careful radiographic analysis will define the curve prior to surgical treatment, the type of curve that is present (thoracic, thoracolumbar/lumbar, etc.), deviation from the center sacral line, the Risser sign, status of the triradiate cartilage, etc. The immediate postoperative radiographs will be analyzed to determine fusion levels and curve, correction. The follow-up radiographs will then be used to compare to the postoperative radiographs to analyze curve progression, trunk shift or other deformities. We will specifically look at the radiographs to determine loss of correction and adding onto distal and proximal levels, as well as curve progression within the instrumented levels.
Previous Research Activities or Publications with Medical Students:
Sucato DJ, Andrade NS, Moore W, Ross Ward D. Lateral vs. Cross Pinning for Supracondylar
Humerus Fractures: A Large Single Institution Study. Paper Presentation at the
73rd Annual Meeting of the American Academy of Orthopaedic Surgeons, Chicago,
IL, March 2006.
Sucato DJ, Agrawal S, McClung A, Johnston C. Thoracolumbar Scoliosis: Comparison of Single Rod Anterior Surgery With/Without Anterior Support. Paper Presentation at the 74th Annual Meeting of the American Academy of Orthopaedic Surgeons, San Diego, CA, February 2007.
White KK, Agrawal S, Sucato DJ. Ultrasonographic Predictors of Pavlik Harness Failure in Ortolani Positive Hips. Podium Presentation at the 2007 Annual Meeting of The Pediatric Orthopaedic Society of North America, Hollywood, FL, May 2007.
Sucato DJ, Agrawal S, Hasley BP, McClung A. Infantile Idiopathic Scoliosis: Natural History and Predictors of Curve Progression. Podium Presentation at the 42nd Annual Scoliosis Research Society Meeting, Edinburgh, Scotland, September 2007.
Sucato DJ, Erken YH, Davis S, Gist T, McClung A, Rathjen KE. Prone Thoracoscopic Release Does Not Adversely Affect Pulmonary Function When Added to a Posterior Spinal Fusion for Severe Spine Deformity. Spine 34 (8): 771-8, 2009.
Project # 2
Project title: Does Traction Improve the Likelihood of Obtaining a Successful Closed Reduction for DDH?
Human subjects IRB approved project number (where applicable): not submitted 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): Patient
Brief Description of Project:
Conservative treatment for developmental dysplasia of the hip (DDH) involves
the institution of a Pavlik harness and/or an abduction orthosis followed by
a closed reduction under anesthesia if the former treatments are unsuccessful.
The goal is to maintain a concentric reduction and allow for the normal growth
and development of the hip joint which may require an open reduction and further
pelvic and femoral osteotomies in the older child. The use of pre-operative
traction in the treatment of the child with hip dysplasia may facilitate reduction
and decrease the incidence of avascular necrosis of the femoral head. Evidence
suggests that its utilization may assist in relaxing the soft tissues around
the hip joint which may increase the likelihood of achieving the closed reduction
without the need for an open surgical reduction.
Several studies have reported on the incidence of avascular necrosis followed a closed reduction with varying results. While some reports demonstrated a decrease in the frequency of avascular necrosis with the use of pre-operative traction and others have demonstrated an increase in the frequency avascular damage without its use, there is no consensus among orthopaedic surgeons on its use, the optimal duration of traction, and the position of the affected hip during traction. Evidence in the literature also suggests that a successful closed and open surgical reduction and a decrease in the incidence of AVN may be achieved without applying traction to the patients with DDH. The ability of pre-operative traction to achieve a successful closed reduction without the need for a further open surgical procedure has not been specifically reported and there is no current study that provides sufficient scientifically substantiated proof that preliminary traction facilitates easier reduction or that it provides a specific benefit.
The goal of this retrospective study is to correlate the use of pre-operative traction to subsequent success or failure of an attempted closed reduction for DDH. A review of all patients less than three years of age treated with a closed/open reduction for DDH from 1980-2009 will be completed. Patients will be divided into two groups based on whether or not they were treated with pre-operative traction and their subsequent treated will be recorded to determine whether a successful closed reduction was achieved with or without the use of pre-operative traction. Residual dysplasia will also be defined according to the Severin classification and an analysis of possible predictors of outcome will also be performed including age of diagnosis, prior treatment with a Pavlik harness or abduction brace, gender, family history, presentation at birth, bilateral involvement, age at reduction, and severity of dislocation.