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Yagi M.,Spine and Scoliosis Service | Yagi M.,National Hospital Organization Murayama Medical Center | Patel R.,Spine and Scoliosis Service | Lawhorne T.W.,Spine and Scoliosis Service | And 4 more authors.
Spine Journal | Year: 2014

Background context: Combined anteroposterior spinal fusion with instrumentation has been used for many years to treat adult thoracolumbar/lumbar scoliosis. This surgery remains a technical challenge to spine surgeons, and current literature reports high complication rates. Purpose: The purpose of this study is to validate a new hybrid technique (a combination of single-rod anterior instrumentation and a shorter posterior instrumentation to the sacrum) to treat adult thoracolumbar/lumbar scoliosis. Study design: This study is a retrospective consecutive case series of surgically treated patients with adult lumbar or thoracolumbar scoliosis. Patient sample :This is a retrospective study of 33 matched pairs of patients with adult scoliosis who underwent two different surgical procedures: a new hybrid technique versus a third-generation anteroposterior spinal fusion. Outcome measures: Preoperative and postoperative outcome measures include self-report measures, physiological measures, and functional measures. Methods: In a retrospective case-control study, 33 patients treated with the hybrid technique were matched with 33 patients treated with traditional anteroposterior fusion based on preoperative radiographic parameters. Mean follow-up in the hybrid group was 5.3 years (range, 2-11 years), compared with 4.6 years (range, 2-10 years) in the control group. Operating room (OR) time, estimated blood loss, and levels fused were collected as surrogates for surgical morbidity. Radiographic parameters were collected preoperatively, postoperatively, and at final follow-up. The Scoliosis Research Society Patient Questionnaire (SRS-22r) and Oswestry Disability Index (ODI) scores were collected for clinical outcomes. Results: Operating room time, EBL, and levels fused were significantly less in the hybrid group compared with the control group (p<.0001). The postoperative thoracic Cobb angle was similar between the hybrid and control techniques (p=.24); however, the hybrid technique showed significant improvement in the thoracolumbar/lumbar curves (p=.004) and the lumbosacral fractional curve (p<.0001). The major complication rate was less in the hybrid group compared with the control group (18% vs. 39%, p=.01). Clinical outcomes at final follow-up were not significantly different based on overall SRS-22r scores and ODI scores. Conclusion: The new hybrid technique demonstrates good long-term results, with less morbidity and fewer complications than traditional anteroposterior surgery select patients with thoracolumbar/lumbar scoliosis. This study received no funding. No potential conflict of interest-associated bias existed. © 2014 Elsevier Inc. All rights reserved.

Yagi M.,National Hospital Organization Murayama Medical Center | Rahm M.,Scott and White Clinic | Gaines R.,Columbia Spine Center and Orthopaedic Group | Maziad A.,Hospital for Special Surgery | And 4 more authors.
Spine | Year: 2014

STUDY DESIGN.: Retrospective case series of surgically treated patients with adult spine deformity (ASD). OBJECTIVE.: To report the incidence of proximal junctional failure (PJF), characterize PJF and evaluate the outcome of revision surgery for PJF. A modified classification is also proposed. SUMMARY OF BACKGROUND DATA.: Although recent reports have shown the catastrophic results of PJF, few reports have shown the incidence, characteristics, and clinical outcomes of PJF in ASD. METHODS.: This retrospective analysis reviewed data entered prospectively into a multicenter database. Surgically treated patients with ASD with a minimum 2-year follow-up were included. PJF was defined as any type of symptomatic proximal junctional kyphosis (PJK) requiring surgery. On the basis of our previous classification, the following modified PJK classification was established: grade A, proximal junctional increase of 10° to 19°; grade B, 20° to 29°; and grade C, 30° or more. Three types of PJK were also defined: ligamentous failure (type 1), bone failure (type 2), and implant/bone interface failure (type 3). An additional criterion was added for the presence or absence of spondylolisthesis above the upper instrumentation vertebra (UIV). RESULTS.: PJF developed in 23 of the 1668 patients with ASD. The incidence of PJF was 1.4%. The mean age was 62.3 ± 7.9 years, and the mean follow-up was 4.0 ± 2.3 years. Seventeen patients had undergone prior surgical procedures. Six patients had UIV above T8, and 17 had UIV below T9. Six patients had associated spondylolisthesis above the UIV (PJF-S), whereas 17 patients did not (PJF-N). The radiographical data show a significant difference in the preoperative sagittal vertical axis between the PJF-S and PJF-N groups, whereas no significant difference was observed in the preoperative sagittal parameters (5.2 ± 3.9 cm vs. 11.4 ± 6.0 cm, P = 0.04). The most common type of PJF was type 2N. The PJF symptoms consisted of intolerable pain (n = 17), neurological deficits (n = 6), and progressive trunk deformity (n = 1). Eleven patients had additional PJK/PJF and 9 required additional revision surgical procedures. CONCLUSION.: The incidence of PJF among surgically treated patients with ASD was 1.4%. The most common type of PJF was 2N. Preoperative large sagittal vertical axis change and large amount of correction was a causative factor for spondylolisthesis above the UIV. After the revision surgery, further PJF was a commonly occurred event. Copyright © 2014 Lippincott Williams & Wilkins.

Yagi M.,National Hospital Organization Murayama Medical Center | King A.B.,Adult and Pediatric Spine and Scoliosis Surgery | Boachie-Adjei O.,Adult and Pediatric Spine and Scoliosis Surgery
Spine | Year: 2012

STUDY DESIGN. A retrospective case series of surgically treated patients with adult scoliosis. OBJECTIVE. The purpose of this study was to evaluate the incidence, risk factors, and natural course of proximal junctional kyphosis (PJK) in a long-term follow-up of patients with adult idiopathic scoliosis undergoing long instrumented spinal fusion. SUMMARY OF BACKGROUND DATA. Although recent reports have showed the prevalence, clinical outcomes, and the possible risk factors of PJK, quite a few reports have showed long-term follow-up outcome. MATERIALS AND METHODS. This is a retrospective review of the charts and radiographs of 76 consecutive patients with adult scoliosis treated with long instrumented spinal fusion. Radiographical measurements and demographic data were reviewed on preoperation, immediate postoperation, 2 years postoperation, 5 years postoperation, and at follow-up. Postoperative Scoliosis Research Society scores and Oswestry Disability Index were also evaluated. Means were compared with Student t test. A P value of less than 0.05 with 95% confidence interval was considered significant. RESULTS. The mean age was 48.8 years (range, 23-75 yr) and the average follow-up was 7.3 years (range, 5-14 yr). PJK has been identified in 17 patients. The Scoliosis Research Society and Oswestry Disability Index did not demonstrate significant differences between PJK group and non-PJK group; 2 patients had additional surgeries performed for local pain. Seventy-six percent of PJK has been identified within 3 months after surgery. Despite the fact that 53% of total degree of PJK was progressed within 3 months after surgery, PJK continuously progressed to the final follow-up. Pre-existing low bone mineral density, posterior spinal fusion (PSF), fusion to sacrum, inappropriate global spine alignment, and greater sagittal vertical axis change were identified as significant risk factors for PJK (P = 0.04, P < 0.001, P = 0.02, P < 0.0001, and P = 0.01). CONCLUSION. In a long-term review of minimum 5 years, 76% of PJK occurred within 3 months after surgery. Pre-existing low bone mineral density, PSF, fusion to the sacrum, inappropriate global spine alignment, and greater sagittal vertical axis change were significant risk factors for PJK. Careful long-term follow-up should be done for a patient with PJK. © 2012, Lippincott Williams &Wilkins.

Takano M.,Keio University | Komaki Y.,Keio University | Komaki Y.,Central Institute for Experimental Animals | Hikishima K.,Keio University | And 7 more authors.
Spine | Year: 2013

STUDY DESIGN.: Basic imaging experiment. OBJECTIVE.: To determine whether in vivo diffusion tensor tractography (DTT) can be used to evaluate the axonal disruption of the chronically compressed spinal cord in tiptoe walking Yoshimura (twy) mice. SUMMARY OF BACKGROUND DATA.: In cervical ossification of the posterior longitudinal ligament, axonal disruption results in motor and sensory functional impairment. Twy mice develop spontaneous calcification in the cervical ligaments, which causes chronic compression of the spinal cord. DTT is emerging as a powerful tool for tracing axonal fibers in vivo. METHODS.: Five twy mice were subjected to DTT at 6, 15, and 20 weeks of age. Magnetic resonance imaging was performed using a 7.0-Tesla magnet (Biospec 70/16; Billerica, MA) with a CryoProbe. Diffusion tensor images were analyzed using TrackVis (Massachusetts General Hospital, MA). Motor performance was evaluated by Rotarod treadmill test and Digigait analysis. Histological analysis was performed by hematoxylin-eosin staining and immunostaining for RT-97 and SMI-31. RESULTS.: High resolution DTT of twy mice in vivo was successful. A lower number of RT-97- or SMI-31-positive fibers were associated with more severe spinal cord compression, which was determined by observing the ligamentous calcification at the C2-C3 level in each twy mouse. The severity of canal stenosis based on magnetic resonance images was strongly correlated with the axial area of the spinal cord. The tract fiber (TF) ratio (the number of TFs at the C2-C3 level/the number of TFs at the C0-C1 level) was strongly correlated with the RT-97/SMI-31-positive area and with motor function (rotarod latency, stride length). Furthermore, a two-part linear regression analysis showed that canal stenosis around 50% to 60% caused a sharp decrease in the TF ratio before the deterioration of motor function. CONCLUSION.: We conclude that DTT could be useful for detecting the early changes associated with the compressed spinal cord in cervical ossification of the posterior longitudinal ligament. Copyright © 2013 Lippincott Williams & Wilkins.

Cao K.,Keio University | Cao K.,Nanchang University | Watanabe K.,Keio University | Hosogane N.,Keio University | And 8 more authors.
Spine | Year: 2014

STUDY DESIGN.: A retrospective, multicenter study. OBJECTIVE.: To investigate the relationship between postoperative shoulder balance and adding-on in Lenke type 2 adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA.: Postoperative shoulder imbalance (PSI) and adding-on are the main postoperative complications occurring at the proximal to upper instrumented vertebra and the distal to the lower instrumental vertebra (LIV), respectively. Inadequate selection of LIV in the selective thoracic fusion surgery may result in postoperative distal adding-on. It remains unclear whether postoperative shoulder balance is associated with postoperative adding-on. METHODS.: Preoperative, postoperative, and 2-year follow-up radiographs of 142 consecutive patients with Lenke type 2 curves who underwent posterior-fusion surgery were analyzed. The patients were grouped into PSI positive and negative at follow-up. Radiographical and categorical factors between patients with and without PSI were compared. The relationship between the radiographical shoulder height and the parameters of adding-on were analyzed. RESULTS.: PSI occurred in 23 patients (16.2%) and distal adding-on was recognized in 20 patients (14.1%) at final follow-up. The occurrence of adding-on was significantly lower in the shoulder imbalance group at follow-up (P < 0.01). There was no shoulder imbalance occurring in the patients with distal adding-on at final follow-up (P < 0.01). Correlation analysis showed that the radiographical shoulder height was positively correlated with the change in the angulation of the first disc below LIV (r = 0.228, P ≤ 0.01) and negatively correlated with the deviation change of the LIV+1 at follow-up (r =-0.254, P ≤ 0.01). CONCLUSION.: The postoperative shoulder balance and postoperative distal adding-on were weakly but significantly associated with each other, and both shoulder imbalance and adding-on need to be prevented in Lenke type 2 curves. Copyright © 2014 Lippincott Williams &Wilkins.

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