Cobb angle

About: Cobb angle is a research topic. Over the lifetime, 3549 publications have been published within this topic receiving 65006 citations.

Pelvic incidence: a fundamental pelvic parameter for three-dimensional regulation of spinal sagittal curves

Abstract: This paper proposes an anatomical parameter, the pelvic incidence, as the key factor for managing the spinal balance. Pelvic and spinal sagittal parameters were investigated for normal and scoliotic adult subjects. The relation between pelvic orientation, and spinal sagittal balance was examined by statistical analysis. A close relationship was observed, for both normal and scoliotic subjects, between the anatomical parameter of pelvic incidence and the sacral slope, which strongly determines lumbar lordosis. Taking into account the Cobb angle and the apical vertebral rotation confers a three-dimensional aspect to this chain of relations between pelvis and spine. A predictive equation of lordosis is postulated. The pelvic incidence appears to be the main axis of the sagittal balance of the spine. It controls spinal curves in accordance with the adaptability of the other parameters.

Adult scoliosis: prevalence, SF-36, and nutritional parameters in an elderly volunteer population

Abstract: Study design A prospective self-assessment analysis and evaluation of nutritional and radiographic parameters in a consecutive series of healthy adult volunteers older than 60 years. Objectives To ascertain the prevalence of adult scoliosis, assess radiographic parameters, and determine if there is a correlation with functional self-assessment in an aged volunteer population. Summary of background data There exists little data studying the prevalence of scoliosis in a volunteer aged population, and correlation between deformity and self-assessment parameters. Methods There were 75 subjects in the study. Inclusion criteria were: age > or =60 years, no known history of scoliosis, and no prior spine surgery. Each subject answered a RAND 36-Item Health Survey questionnaire, a full-length anteroposterior standing radiographic assessment of the spine was obtained, and nutritional parameters were analyzed from blood samples. For each subject, radiographic, laboratory, and clinical data were evaluated. The study population was divided into 3 groups based on frontal plane Cobb angulation of the spine. Comparison of the RAND 36-Item Health Surveys data among groups of the volunteer population and with United States population benchmark data (age 65-74 years) was undertaken using an unpaired t test. Any correlation between radiographic, laboratory, and self-assessment data were also investigated. Results The mean age of the patients in this study was 70.5 years (range 60-90). Mean Cobb angle was 17 degrees in the frontal plane. In the study group, 68% of subjects met the definition of scoliosis (Cobb angle >10 degrees). No significant correlation was noted among radiographic parameters and visual analog scale scores, albumin, lymphocytes, or transferrin levels in the study group as a whole. Prevalence of scoliosis was not significantly different between males and females (P > 0.03). The scoliosis prevalence rate of 68% found in this study reveals a rate significantly higher than reported in other studies. These findings most likely reflect the targeted selection of an elderly group. Although many patients with adult scoliosis have pain and dysfunction, there appears to be a large group (such as the volunteers in this study) that has no marked physical or social impairment. Conclusions Previous reports note a prevalence of adult scoliosis up to 32%. In this study, results indicate a scoliosis rate of 68% in a healthy adult population, with an average age of 70.5 years. This study found no significant correlations between adult scoliosis and visual analog scale scores or nutritional status in healthy, elderly volunteers.

The adult scoliosis

Abstract: Adult scoliosis is defined as a spinal deformity in a skeletally mature patient with a Cobb angle of more than 10 degrees in the coronal plain. Adult scoliosis can be separated into four major groups: Type 1: Primary degenerative scoliosis, mostly on the basis of a disc and/or facet joint arthritis, affecting those structures asymmetrically with predominantly back pain symptoms, often accompanied either by signs of spinal stenosis (central as well as lateral stenosis) or without. These curves are often classified as "de novo" scoliosis. Type 2: Idiopathic adolescent scoliosis of the thoracic and/or lumbar spine which progresses in adult life and is usually combined with secondary degeneration and/or imbalance. Some patients had either no surgical treatment or a surgical correction and fusion in adolescence in either the thoracic or thoracolumbar spine. Those patients may develop secondary degeneration and progression of the adjacent curve; in this case those curves belong to the type 3a. Type 3: Secondary adult curves: (a) In the context of an oblique pelvis, for instance, due to a leg length discrepancy or hip pathology or as a secondary curve in idiopathic, neuromuscular and congenital scoliosis, or asymmetrical anomalies at the lumbosacral junction; (b) In the context of a metabolic bone disease (mostly osteoporosis) combined with asymmetric arthritic disease and/or vertebral fractures. Sometimes it is difficult to decide, what exactly the primary cause of the curve was, once it has significantly progressed. However, once an asymmetric load or degeneration occurs, the pathomorphology and pathomechanism in adult scoliosis predominantly located in the lumbar or thoracolumbar spine is quite predictable. Asymmetric degeneration leads to increased asymmetric load and therefore to a progression of the degeneration and deformity, as either scoliosis and/or kyphosis. The progression of a curve is further supported by osteoporosis, particularly in post-menopausal female patients. The destruction of facet joints, joint capsules, discs and ligaments may create mono- or multisegmental instability and finally spinal stenosis. These patients present themselves predominantly with back pain, then leg pain and claudication symptoms, rarely with neurological deficit, and almost never with questions related to cosmetics. The diagnostic evaluation includes static and dynamic imaging, myelo-CT, as well as invasive diagnostic procedures like discograms, facet blocks, epidural and root blocks and immobilization tests. These tests may correlate with the clinical and the pathomorphological findings and may also offer the least invasive and most rational treatment for the patient. The treatment is then tailored to the specific symptomatology of the patient. Surgical management consists of either decompression, correction, stabilization and fusion procedures or a combination of all of these. Surgical procedure is usually complex and has to deal with a whole array of specific problems like the age and the general medical condition of the patient, the length of the fusion, the condition of the adjacent segments, the condition of the lumbosacral junction, osteoporosis and possibly previous scoliosis surgery, and last but not least, usually with a long history of chronified back pain and muscle imbalance which may be very difficult to be influenced. Although this surgery is demanding, the morbidity cannot be considered significantly higher than in other established orthopaedic procedures, like hip replacement, in the same age group of patients. Overall, a satisfactory outcome can be expected in well-differentiated indications and properly tailored surgical procedures, although until today prospective, controlled studies with outcome measures and pre- and post-operative patient's health status are lacking. As patients, who present themselves with significant clinical problems in the context of adult scoliosis, get older, minimal invasive procedures to address exactly the most relevant clinical problem may become more and more important, basically ignoring the overall deformity and degeneration of the spine.

Dual growing rod technique for the treatment of progressive early-onset scoliosis: a multicenter study.

Abstract: Study design A retrospective case review of children treated with dual growing rod technique at our institutions. Patients included had no previous surgery and a minimum of 2 years follow-up from initial surgery. Objectives To determine the safety and effectiveness of the previously described dual growing rod technique in achieving and maintaining scoliosis correction while allowing spinal growth. Summary of background data Historically, the growing rod techniques have used a single rod and the reported results have been variable. There has been no published study exclusively on the results of dual growing rod technique for early-onset scoliosis. Methods From 1993 to 2001, 23 patients underwent dual growing rod procedures using pediatric Isola instrumentation and tandem connectors. Diagnoses included infantile and juvenile idiopathic scoliosis, congenital, neuromuscular, and other etiologies. All had curve progression over 10 degrees following unsuccessful bracing or casting. Of 189 total procedures within the treatment period, 151 were lengthenings with an average of 6.6 lengthenings per patient. Analysis included age at initial surgery and final fusion (if applicable), number and frequency of lengthenings, and complications. Radiographic evaluation included measured changes in scoliosis Cobb angle, kyphosis, lordosis, frontal and sagittal balance, length of T1-S1 and instrumentation over the treatment period, and space available for lung ratio. Results The mean scoliosis improved from 82 degrees (range, 50 degrees-130 degrees) to 38 degrees (range, 13 degrees-66 degrees) after initial surgery and was 36 degrees (range, 4 degrees-53 degrees) at the last follow-up or post-final fusion. T1-S1 length increased from 23.01 (range, 13.80-31.20) to 28.00 cm (range, 19.50-35.50) after initial surgery and to 32.65 cm (range, 25.60-41.00) at last follow-up or post-final fusion with an average T1-S1 length increase of 1.21 cm per year (range, 0.13-2.59). Seven patients reached final fusion. The space available for lung ratio in patients with thoracic curves improved from 0.87 (range, 0.7-1.1) to 1.0 (range, 0.79-1.23, P = 0.01). During the treatment period, complications occurred in 11 of the 23 patients (48%), and they had a total of 13 complications. Four of these patients (17%) had unplanned procedures. Following final fusion, 2 patients required extensions of their fusions because of curve progression and lumbosacral pain. Conclusion The dual growing rod technique is safe and effective. It maintains correction obtained at initial surgery while allowing spinal growth to continue. It provides adequate stability, increases the duration of treatment period, and has an acceptable rate of complication compared with previous reports using the single rod technique.

Curve progression in idiopathic scoliosis.

Abstract: One hundred and thirty-three curves in 102 patients who were followed for an average of 40.5 years were evaluated to quantitate curve progression after skeletal maturity and for prognostic factors leading to curve progression. Sixty-eight per cent of the curves progressed after skeletal maturity. In general, curves that were less than 30 degrees at skeletal maturity tended not to progress regardless of curve pattern. In thoracic curves the Cobb angle, apical vertebral rotation, and the Mehta angle were important prognostic factors. In lumbar curves the degree of apical vertebral rotation, the Cobb angle, the direction of the curve, and the relationship of the fifth lumbar vertebra to the intercrest line were of prognostic value. Translatory shifts played an important role in curve progression. Curves that measured between 50 and 75 degrees at skeletal maturity, particularly thoracic curves, progressed the most.