Kyung-Soo Suk

Delayed vertebral collapse with neurological deficits secondary to osteoporosis

Delayed vertebral collapse after osteoporotic spinal fractures may cause progressive kyphosis, neurological deficits, and chronic back pain. We treated 14 consecutive patients with posterolateral decompression and posterior reconstruction and followed them over a period ranging from 24 to 54 months. The mean age was 67 (range: 62–72) years and the fracture level was T12 and L1. Seven patients were graded as Frankel stage C and seven as stage D. The mean segmental kyphotic angle was 22.6° (7–29°) preoperatively, 4.4° (1–6°) postoperatively, and 6.8° (2–15°) at the final follow-up. The pain score on a visual analogue scale improved from 9.5 preoperatively to 2.7 postoperatively, and the neurological status improved in all patients. Bone fusion was present 9 months after operation. Of four surgical complications, two were dural tears, one a superficial infection, and there was one death due to an acute adrenal insufficiency. Posterolateral decompression with posterior reconstruction is a useful treatment for patients with delayed osteoporotic vertebral collapse.RésuméLe collapsus vertébral secondaire, après une fracture vertébrale ostéoporotique, peut créer une cyphose progressive, un déficit neurologique et des lombalgies chroniques. Nous avons traité 14 malades consécutifs par décompression postérolaterale et reconstruction postérieure et les avons suivis de 24 à 54 mois. Lâge moyen était 67 (62–72) années. Le niveau de la fracture était T12 et L1. Sept malades ont été notés comme Frankel stade C et sept comme stade D. Langle cyphotique segmentaire moyen était 22.6° (7–29°) avant lopération, 4.4° (1–6°) postopératoire, et 6.8° (2–15°) au dernier examen. Le score de la douleur sur une échelle analogue visuelle sest amélioré de 9.5 en préopératoire à 2.7 en postopératoire. Le statut neurologique a été amélioré chez tous les malades. La fusion osseuse était visible 9 mois après la chirurgie. Il y avait quatre complications chirurgicales, deux brèches duremériennes, une infection superficielle et un décés dû à une insuffisance surrénale aiguë. La décompression posterolateral avec reconstruction postérieure est une bonne option de traitement chez les malades avec collapsus vertébral différé.

Prevertebral soft tissue swelling after anterior cervical discectomy and fusion with plate fixation

Airway complications after anterior cervical surgery are rare but potentially lethal. The purpose of this study was to identify the natural course of prevertebral soft tissue swelling after one- or two-level anterior cervical discectomy and fusion (ACDF) in order to prevent lethal airway obstruction after ACDF. Eighty-seven patients scheduled for one- or two-level ACDF were studied prospectively. Lateral radiographs of the cervical spine were taken preoperatively, postoperatively on the day of surgery and on the first, second, third, fourth, and fifth days after operation. Prevertebral soft tissue was measured from C2 to C6 on cervical spine lateral radiographs. The anteroposterior (AP) thickness of the prevertebral soft tissue was measured at each cervical level from C2 to C6. Prevertebral soft tissue swelling occurred postoperatively and increased markedly on the second day after operation. The maximum swelling was found on the second and third days. In fusions above C5 swelling was most prominent at C2, 3. Gradual decrease in swelling was observed after the fourth postoperative day. Prominent swelling was noted at the second, third, and fourth cervical levels. There was no significant difference in swelling when comparing one-level and two-level ACDF. Only one patient required reintubation (1.1%). In conclusion, in this prospective study of 87 patients fused at one or two levels in the cervical spine peak prevertebral soft tissue swelling was observed on the second and third days after the surgery.RésuméLes complications aériennes après chirurgie cervicale antérieure sont rares mais potentiellement léthales. Le sujet de ce travail est d’étudier l’évolution de l’œdème prévertébral après discectomie antérieure et fusion à un ou deux niveaux ( ACDF) pour prévenir une obstruction aérienne. 87 patients devant avoir un ACDF a un ou deux niveaux étaient étudiés prospectivement. Des radiographies de profil de la colonne cervicale ont été faites avant l’opération, après l’opération le jour de la chirurgie, puis les premier, deuxième, troisième, quatrième et cinquième jours après. Les parties molles prévertébrales étaient mesurées de C2 à C6 sur ces radiographies. L’œdème prévertébral apparaissait en postopératoire et avait une augmentation marqué le deuxième jour après la chirurgie. Dans les fusions au-dessus de C5 l’œdème prédominait en C2, C3. La régression de l’œdème était observée après le quatrième jour post-opératoire. Un œdème prononcé était noté aux deuxième, troisième et quatrième niveau cervical. Il n’y avait pas de différence significative dans l’oedème en comparant un et deux niveaux de discectomie-fusion. Seulement 1 patient a eu besoin d’une ré-intubation (1,1%). En conclusion , dans cette série, l’acmé de l’œdème prévertébral était observée les deuxième et troisième jours après l’opération.

Factors determining cervical spine sagittal balance in asymptomatic adults: correlation with spinopelvic balance and thoracic inlet alignment

BACKGROUND CONTEXTnBased on the previous studies, cervical lordosis (CL) is a parameter influenced by thoracic kyphosis (TK); however, the correlations still remain unclear. Few studies have analyzed the correlations between the cervical spine lordosis and global spinopelvic balance. To date, there has been no study focused on the factors determining cervical spine sagittal balance.nnnPATIENT SAMPLEnSeventy-seven asymptomatic volunteers without the history of symptoms related to whole spine.nnnOUTCOME MEASURESnStatistical significance of correlations of radiographic parameters on cervical spine and whole-spine standing lateral radiograph.nnnPURPOSEnTo analyze the factors determining cervical spine sagittal balance, including global spinopelvic balance and thoracic inlet (TI) alignment in asymptomatic adults.nnnSTUDY DESIGNnA prospective radiographic study.nnnMETHODSnCervical and whole-spine standing lateral radiographs were taken to analyze the following parameters: spinopelvic parameters pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and TK; TI parameters thoracic inlet angle (TIA) and T1 slope; and cervical spine parameters C0-C2, C2-C7, and C0-C7 angles and cervical tilting. Statistical analysis was performed using the Pearson correlation coefficients and multiple regression analysis.nnnRESULTSnAll the parameters showed a normal distribution. There was a significant sequential linkage between PI and SS (r=0.653), SS and LL (r=0.807), LL and TK (r=-0.516), and TK and C0-C7 angle (r=-0.322). There was a significant relationship between TK and T1 slope (r=0.351) but no significant relationship between TK and TIA. There were significant sequential relationships between TIA and T1 slope (r=0.694), T1 slope and C2-C7 angle (r=-0.624), and C2-C7 and C0-C2 angles (r=-0.547). T1 slope was the only parameter that demonstrated a significant correlation with both SP and TI parameters. A linear regression model showed that T1 slope had a stronger relationship with TIA (r=0.694) than TK (r=0.351).nnnCONCLUSIONSnT1 slope was a key factor determining cervical spine sagittal balance. Both spinopelvic balance and TI alignment have a significant influence on cervical spine sagittal balance via T1 slope, but TIA had a stronger effect than TK. An individual with large T1 slope required large CL to preserve physiologic sagittal balance of the cervical spine. The results of the present study could serve as baseline data for further studies on the cervical spine sagittal balance in various clinical conditions including the surgical reconstruction of lordosis.

Reevaluation of the Pavlov Ratio in Patients with Cervical Myelopathy

Background This study was designed to reevaluate the effectiveness of the Pavlov ratio in patients with cervical myelopathy. Methods We studied 107 patients who underwent open door laminoplasty for the treatment of cervical myelopathy between the C3 to C7 levels. We determined the Pavlov ratio on preoperative and postoperative cervical spine lateral radiographs, the vertebral body-to-canal ratio on sagittal reconstruction CT scans, and the vertebral body-to-cerebrospinal fluid (CSF) column ratio on T2-weighted sagittal MR images from C3 to C6. The severity of myelopathy was determined using the JOA score on both preoperative and postoperative images. The recovery rate was also calculated. The Pavlov ratio in plain radiographs from patients with myelopathy was compared with the ratio of the vertebral body to the spinal canal on CT and MRI. Results The average Pavlov ratio between C3 and C6 ranged from 0.71 to 0.76. On CT scan, the average vertebral body-to-canal ratio between C3 and C6 ranged from 0.62 to 0.66. On MRI, the vertebral body-to-CSF column ratio between C3 and C6 ranged between 0.53 and 0.57. A positive correlation was noted between the Pavlov ratio and the vertebral body-to-canal ratio on sagittal-reconstruction CT (correlation coefficient = 0.497-0.627, p = 0.000) and between the Pavlov ratio and the vertebral body-to-CSF column ratio on MRI (correlation coefficient = 0.511-0.649, p = 0.000). Conclusions We demonstrated a good correlation between the Pavlov ratio and both the vertebral body-to-canal ratio on CT and the vertebral body-to-CSF column ratio on MRI. Therefore, the Pavlov ratio can be relied upon to predict narrowing of the cervical spinal canal in the sagittal plane.

Biomechanical Changes of the Lumbar Segment after Total Disc Replacement : Charite ® , Prodisc ® and Maverick ® Using Finite Element Model Study

OBJECTIVEnThe purpose of this study was to analyze the biomechanical effects of three different constrained types of an artificial disc on the implanted and adjacent segments in the lumbar spine using a finite element model (FEM).nnnMETHODSnThe created intact model was validated by comparing the flexion-extension response without pre-load with the corresponding results obtained from the published experimental studies. The validated intact lumbar model was tested after implantation of three artificial discs at L4-5. Each implanted model was subjected to a combination of 400 N follower load and 5 Nm of flexion/extension moments. ABAQUS version 6.5 (ABAQUS Inc., Providence, RI, USA) and FEMAP version 8.20 (Electronic Data Systems Corp., Plano, TX, USA) were used for meshing and analysis of geometry of the intact and implanted models.nnnRESULTSnUnder the flexion load, the intersegmental rotation angles of all the implanted models were similar to that of the intact model, but under the extension load, the values were greater than that of the intact model. The facet contact loads of three implanted models were greater than the loads observed with the intact model.nnnCONCLUSIONnUnder the flexion load, three types of the implanted model at the L4-5 level showed the intersegmental rotation angle similar to the one measured with the intact model. Under the extension load, all of the artificial disc implanted models demonstrated an increased extension rotational angle at the operated level (L4-5), resulting in an increase under the facet contact load when compared with the adjacent segments. The increased facet load may lead to facet degeneration.