RESUMEN
STUDY DESIGN: Retrospective review of scoliosis progression, pulmonary and cardiac function in a series of patients with Duchenne Muscular Dystrophy (DMD). OBJECTIVE: To determine whether operative treatment of scoliosis decreases the rate of pulmonary function loss in patients with DMD. SUMMARY OF BACKGROUND DATA: It is generally accepted that surgical intervention should be undertaken in DMD scoliosis once curve sizes reach 35° to allow intervention before critical respiratory decline has occurred. There are conflicting reports, however, regarding the effect of scoliosis stabilization on the rate of pulmonary function decline when compared to nonoperative cohorts. METHODS: We reviewed spinal radiographs, echocardiograms, and spirometry, hospital, and operative records of all patients seen at our tertiary referral center from July 1, 1992 to June 1, 2007. Data were recorded to Microsoft Excel (Microsoft, Redmond, WA) and analyzed with SAS (SAS Institute, Cary, NC) and R statistical processing software (www.r-project.org). RESULTS: The percent predicted forced vital capacity (PPFVC) decreased 5% per year before operation. The mean PPFVC was 54% (SD = 21%) before operation with a mean postoperative PPFVC of 43% (SD = 14%). Surgical treatment was associated with a 12% decline in PPFVC independent of other treatment variables. PPFVC after operation declined at a rate of 1% per year and while this rate was lower, it was not significantly different than the rate of decline present before operation (P = 0.18). Cardiac function as measured by left ventricular fractional shortening declined at a rate of 1% per year with most individuals exhibiting a left ventricular fractional shortening rate of more than 30 before operation. CONCLUSION: Operative treatment of scoliosis in DMD using the Luque Galveston method was associated with a reduction of forced vital capacity related to operation. The rate of pulmonary function decline after operation was not significantly reduced when compared with the rate of preoperative forced vital capacity decline.
Asunto(s)
Corazón/fisiopatología , Pulmón/fisiopatología , Distrofia Muscular de Duchenne/complicaciones , Escoliosis/cirugía , Adolescente , Adulto , Niño , Humanos , Masculino , Estudios Retrospectivos , Escoliosis/complicaciones , Escoliosis/fisiopatología , Columna Vertebral/fisiopatología , Columna Vertebral/cirugía , Resultado del Tratamiento , Función Ventricular Izquierda , Capacidad Vital , Adulto JovenRESUMEN
STUDY DESIGN: Whole human cadaver model to assess a common diagnostic test for cervical spine stability. OBJECTIVE: Determine criteria that can be used to determine if sagittal plane angular motion of the head/neck during a cervical spine flexion/extension study is adequate to reliably assess intervertebral motion (IVM). SUMMARY OF BACKGROUND DATA: Flexion/Extension radiographs of the cervical spine are commonly used to help identify specific abnormalities in IVM. Several authors have recognized that inadequate patient effort can make flexion/extension studies unreliable, but validated guidelines for assessing the adequacy of these studies are not available. METHODS: Increasingly severe anterior-to-posterior (N = 6), and posterior-to-anterior (N = 6) soft tissue injuries were simulated in the cervical spines of 12 human cadavers. Sagittal plane radiographic images were taken with 4 gradually increasing amounts of overall flexion and extension motion of the head. IVM was measured for each level of sagittal plane rotation of the head/neck using previously validated computer-assisted methods. RESULTS: With less than 60 degrees of sagittal plane rotation of the head/neck, intervertebral rotation or displacement was almost never greater than the 95% confidence interval previously established for asymptomatic people. Even with 60 degrees or more motion, intervertebral rotation and displacement were within normal limits after extensive damage to the soft-tissues. The center-of-rotation was the most sensitive measure for detecting soft tissue damage. CONCLUSION: The results of this study suggest that clinicians should make sure patients can flex and extend their head/neck to a minimum range of 60 degrees before evaluating them for a dynamic motion study to assess cervical spine stability. Even with adequate motion, interverterbral rotation and translation can remain within normal limits in the presence of extensive soft tissue damage. The most sensitive measure for detecting soft tissue damage was center-of-rotation although it lacks specificity, particularly in the presence of underlying degenerative changes, and is not readily assessed in most clinical situations.