Computer Tomography Evaluation of Cotrel-Dubousset Instrumentation in Idiopathic Scoliosis

Ecker, Malcolm L.; Betz, Randal R.; Trent, Peter S.; Mahboubi, Soroosh; Mesgarzadeh, Mamed; Bonakdapour, Akbar; Drummond, Denis S.; Clancy, Michael

doi:10.1097/00007632-198810000-00015

Cited by 74 publications

(31 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Like traditional measurements of axial rotation on frontal radiographs, CT scans are accurate only for very small vertebral tilts [1,2,10,16,28,34]. When the tilt increases simultaneously in the frontal and the sagittal planes, the distortion increases as a parabola and the traditional measurements become unworkable.…”

Section: Discussionmentioning

confidence: 99%

Access to a three-dimensional measure of vertebral axial rotation

1998

View full text Add to dashboard Cite

IntroductionThe spinal distortion that gives rise to a scoliotic curve includes both a rib hump and an axial rotation of the apical vertebra. The location and extent of axial rotation can provide considerable information on the nature of the deformity. The earliest method of detecting an axial rotation was from the lateral displacement of the shadow of the spinal process with respect to that of the vertebral body on coronal plain radiographs. Subsequently, Grossiord et al. [12] and Nash and Moe [21] showed that the position of the pedicle shadow with respect to those of the vertebral body wedges and the posterior arch provided a more sensitive index. They also showed that accurate calibration of the X-ray machine was most important, as the coronal view of the spine provides only a frontal projection of the vertebrae, and hence a qualitative evaluation of the axial rotation.Several authors [4, 5,7,8,19,20,24,32] have used a variety of geometrical formulae that take into account the diverse anatomical frames of the vertebrae as projected in coronal radiographs to develop a quantitative measurement of axial rotation, implicitly referred to the global referential system. Indeed, the concept of axial rotation of the scoliotic curve vertebrae requires a single referential system for all the vertebrae. The accuracy of these methods has been assessed [14,28,29,32,35] and the shadows of the anatomical features were found to be distorted [9, 25, 31 35]. These evaluations have also been compared to those drawn from CT scans and ultrasound images [1, 2,12,16,17,18,28], and it has been shown that the measurement technique must be standardized to allow the comparative assessment of findings [29].However, none of the above methods use sagittal data, consequently they do not produce a true three-dimensional (3D) measurement of the axial rotation of each vertebra. The 2D data provide what is referred to in this paper as "apparent rotation". True 3D measurements must also take into account the sagittal tilt of the vertebrae. This report analyses the concept of introduced rotation and its implications, and then describes a method of obtaining a true 3D evaluation of vertebral axial rotation.Abstract Scoliotic curvatures can only be assessed through three-dimensional (3D) procedures. Measurement of the axial vertebral rotation appears to be of primary importance for such techniques. Nevertheless, traditional methods are based only on 2D data, obtained through antero-posterior radiographic projections of the spine. A 3D method is described in this study, taking into account the sagittal tilt of the vertebrae. Only such a measurement provides a real 3D method for a true appraisal of the scoliotic spine. The practical implications are developed.

show abstract

Section: Discussionmentioning

confidence: 99%

Access to a three-dimensional measure of vertebral axial rotation

1998

View full text Add to dashboard Cite

show abstract

“…Instrumented correction of scoliotic deformities has evolved from Harrington rods, to Cotrel-Dubousset (CD) instrumentation, to the more recent advent of thoracic pedicle screw fixation [1][2][3][4][5][6]. Although Harrington rod distraction improved coronal deformity, sagittal plane imbalance was often associated with a high incidence of flatback syndrome [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Five-year clinical and radiographic outcomes using pedicle screw only constructs in the treatment of adolescent idiopathic scoliosis

et al. 2012

View full text Add to dashboard Cite

Purpose To determine the mid-term clinical and radiographic impact of pedicle screw fixation in patients with adolescent idiopathic scoliosis (AIS). Methods A multicenter AIS database was retrospectively queried to identify 99 consecutive patients who underwent posterior spinal fusion using an all pedicle screw construct with a minimum of 5-year follow-up. Radiographic and clinical parameters were reviewed at regular intervals up to 5 years. ResultsThe mean age was 14.4 ± 2.0 years with 79 % being female. The mean preoperative major curve was 51.7 ± 14.2°with a mean correction of 66 and 64 % at 2 and 5 years (p = 0.16). Pre-op thoracic kyphosis averaged 22.3 ± 12.9°and was 18.4 ± 10.6°at 5 years with no significant change from 2 years (p = 0.33). SRS total and domain scores demonstrated significant improvements at 2 years, which were slightly decreased at 5 years (p = 0.06). SRS scores of self-image (p = 0.99) and satisfaction (p = 0.18) were significantly improved after surgery with minimal change by 5 years. The change in SRS total scores from 2 to 5 years was attributed to differences in SRS scores of pain and mental health (p \ 0.05). Conclusions Intermediate follow-up of patients with AIS treated with an all pedicle screw construct demonstrates maintenance of their coronal, and sagittal plane correction between 2-and 5-year follow-up. At 5 years, improvements in SRS scores were consistent with 2-year values, except for a decline in pain and mental health scores.

show abstract

“…However, the literature is contradictory on the effect on axial rotation and rib cage deformity. In most literature it is suggested that axial plane correction is limited [13,19,21,33].…”

Section: Introductionmentioning

confidence: 99%

“…However, the literature is contradictory on the effect on axial rotation and rib cage deformity. In most literature it is suggested that axial plane correction is limited [13,19,21,33].Abstract The biocompatibility and functionality of a new scoliosis correction device, based on the properties of the shape-memory metal nickel-titanium alloy, were studied. With this device, the shape recovery forces of a shape-memory metal rod are used to achieve a gradual threedimensional scoliosis correction.…”

mentioning

confidence: 99%

Scoliosis correction with shape-memory metal: results of an experimental study

et al. 2001

View full text Add to dashboard Cite

IntroductionOperations for scoliosis are designed to correct the deformity and to prevent its progression by achieving a solid fusion. In 1962, Harrington introduced the use of spinal instrumentation for the surgical treatment of scoliosis [16]. In the 1980s, the development of spinal instrumentation expanded considerably. New anterior and posterior systems were introduced [2,6,10,12,18,32]. With these advanced segmental systems, better corrections are possible in the coronal and the sagittal plain in comparison with Harrington instrumentation. However, the literature is contradictory on the effect on axial rotation and rib cage deformity. In most literature it is suggested that axial plane correction is limited [13,19,21,33].Abstract The biocompatibility and functionality of a new scoliosis correction device, based on the properties of the shape-memory metal nickel-titanium alloy, were studied. With this device, the shape recovery forces of a shape-memory metal rod are used to achieve a gradual threedimensional scoliosis correction. In the experimental study the action of the new device was inverted: the device was used to induce a scoliotic curve instead of correcting one. Surgical procedures were performed in six pigs. An originally curved squared rod, in the cold condition, was straightened and fixed to the spine with pedicle screws. Peroperatively, the memory effect of the rod was activated by heating the rod to 50°C by a low-voltage, high-frequency current. After 3 and after 6 months the animals were sacrificed. The first radiographs, obtained immediately after surgery, showed in all animals an induced curve of about 40°Cobb angle -the original curve of the rod. This curve remained constant during the followup. The postoperative serum nickel measurements were around the detection limit, and were not significantly higher compared to the preoperative nickel concentration. Macroscopic inspection after 3 and 6 months showed that the device was almost overgrown with newly formed bone. Corrosion and fretting processes were not observed. Histologic examination of the sections of the surrounding tissues and sections of the lung, liver, spleen and kidney showed no evidence of a foreign body response. In view of the initiation of the scoliotic deformation, it is expected that the shape-memory metal based scoliosis correction device also has the capacity to correct a scoliotic curve. Moreover, it is expected that the new device will show good biocompatibility in clinical application. Extensive fatigue testing of the whole system should be performed before clinical trials are initiated.

show abstract

Computer Tomography Evaluation of Cotrel-Dubousset Instrumentation in Idiopathic Scoliosis

Cited by 74 publications

References 0 publications

Access to a three-dimensional measure of vertebral axial rotation

Access to a three-dimensional measure of vertebral axial rotation

Five-year clinical and radiographic outcomes using pedicle screw only constructs in the treatment of adolescent idiopathic scoliosis

Scoliosis correction with shape-memory metal: results of an experimental study

Contact Info

Product

Resources

About