Toshiki Saito

Adjacent Segment Disease After Posterior Lumbar Interbody Fusion: Based on Cases With a Minimum of 10 Years of Follow-up.

Study Design. Retrospective case-controlled study. Objective. To investigate the incidence of adjacent segment degeneration (ASD) and the associated risk factors during a period of at least 10 years after posterior lumbar interbody fusion (PLIF). Summary of Background Data. ASD is a problematic sequelae after spinal fusion surgery. Few long-term follow-up studies have investigated ASD after PLIF; thus, magnetic resonance imaging (MRI) data available for the evaluation of postoperative changes associated with ASD are limited. Method. One hundred one patients were retrospectively enrolled. The minimum follow-up was 10 years after surgery. Preoperative and postoperative (2, 5, and 10 yr after surgery) Radiographs and MRI images were evaluated. Disc height, vertebral slip, and intervertebral angle were examined on radiographical images. Disc degeneration and spinal stenosis on MRI images were evaluated. Risk factors for developing early-onset radiographical ASD were evaluated using a multivariate logistic regression analysis. Result. The degenerative changes in disc height, vertebral slip, and intervertebral angle on radiographs 10 years after surgery were found in 12, 36, and 17 cases, respectively, at the cranial-adjacent level and in 3, 6, and 11 cases, respectively, at the caudal-adjacent level. Increased disc degeneration and spinal stenosis worsening were observed in 62 and 68 cases, respectively, at the cranial-adjacent level and in 25 and 12 cases, respectively, at the caudal-adjacent level on MRI 10 years after surgery. Ten patients (9.9%) required reoperation, and 80% of revision surgeries were performed more than 5 years after the initial surgery. High pelvic incidence was a risk factor for developing early-onset radiographical ASD. Conclusion. The majority of the reoperations for ASD were performed more than 5 years after the initial lumbar fusion surgery, although the progression of radiographical ASD began in the early postoperative period. A high degree of pelvic incidence was a risk factor for developing early-onset radiographical ASD. Obtaining appropriate lumbar lordosis in PLIF is important for preventing ASD. Level of Evidence: 4

Comparison of Surgical Outcomes Between Anterior Fusion and Posterior Fusion in Patients With AIS Lenke Type 1 or 2 that Underwent Selective Thoracic Fusion -Long-term Follow-up Study Longer Than 10 Postoperative Years.

Study Design. A retrospective comparative study. Objective. We compared the outcomes between patients treated either by selective thoracic anterior (ASF) or posterior spinal fusion (PSF), with a minimum 10-year follow-up. Summary of Background Data. A retrospective long-term follow-up study was conducted to compare PSF (P group) and ASF (A group) with Lenke type 1 or 2. There were no significant differences in the correction rate and incidence of degenerative discs (DDs) on the lumbar area. Loss of correction was greater in the A group. Methods. The inclusion criteria were female, AIS Lenke type 1 or 2, minimum 10-year follow-up, MRI check-up at 5 years and 10 years postop. The number of patients, age, and curve types at the time of surgery were matched in both groups. Complications, pulmonary function, and SRS-30 were also evaluated. Results. P group: adding-on (AO) occurred in 14 patients. Two patients demonstrated progression of scoliosis >5° during follow-up. Degenerative discs occurred in 43% of patients at 10 years postop. There were significant differences in the %VC and FVC before surgery and at the final visit (P < 0.05). A group: AO occurred in 16 patients. Eleven showed progression of scoliosis >5°. Degenerative disc was recognized in 53% of the patients. There was no significant difference in the pulmonary function. There was a significant difference in selfimage score in the SRS-30 between the two groups (P < 0.05). Conclusion. Correction of scoliosis was significantly better ASF than PSF immediately postop. Greater loss of correction occurred with ASF at postop 10 years. Although shorter segments could be fused by ASF, there was no significant difference in the incidence of DDs. Pulmonary function test results improved in the P group and were restored in the A group during the perioperative period.

Proximal Junctional Kyphosis Following Posterior Hemivertebra Resection and Short Fusion in Children Younger Than 10 Years.

Study Design: A retrospective study. Objective: To investigate whether proximal junctional kyphosis (PJK) or obvious proximal junctional angle (PJA) changes in the sagittal plane develops following short fusion in children younger than 10 years of age with congenital scoliosis, and to investigate the possible risk factors. Summary of Background Data: PJK following long spinal fusion in adolescents and adults is a serious postoperative complication. Although the same problem may occur in patients with early-onset scoliosis who have undergone spine fusion, few studies have been reported any relationship between PJK and spinal fusion in young children with congenital scoliosis. Materials and Methods: Thirty-seven children treated in a single institution between 1998 and 2010 were reviewed retrospectively. The inclusion criteria included (1) younger than 10 years of age at the time of operation; (2) simple congenital deformity; (3) hemivertebra treated by posterior hemivertebrectomy with short fusion at a maximum of 5 motion segments; and (4) minimum follow-up for 2 years. The PJA from the caudal endplate of the upper instrumented vertebra (UIV) to the cephalad endplate of the vertebra adjacent to the UIV, thoracic kyphosis (T5–T12), lumbar lordosis (T12–S1), global sagittal balance, and magnitude of scoliosis of the major curves and upper compensated curves were measured on lateral radiographs. PJK was defined by a PJA>10 degrees during the follow-up and at least 10 degrees greater than the preoperative or early postoperative measurement. Wilcoxon tests were performed for statistical analysis. Results: PJK occurred in 7 of 37 patients (18.9%), during an average of 4.5±3.2 years of follow-up (2–12 y). The UIV level of children with PJK was on T9 in 4 patients, and T11, T12, and L1 in 1. Screw malposition at UIV was confirmed by postoperative computed tomography images in 6 patients. Only 1 patient with a screw deviation did not develop PJK during the follow-up period. None of the patients with PJK was symptomatic, and no patients required revision surgery because of PJK. PJK occurred and progressed during the first 6 months after surgery followed by almost no progression or slight improvement in patients that could be followed up beyond 6 months postoperatively; in association with an increase of the lumbar lordosis. Conclusions: PJK occurred in pediatric patients with simple congenital deformities following hemivertebrectomy and short fusion. PJK was more common in patients with (1) greater immediately postoperative segmental kyphosis and PJA; (2) screw malposition on the UIV; and (3) hemivertebra located on the lower thoracic or the thoracolumbar region.

The Effects of Spinal Fusion on Lumbar Disc Degeneration in Patients with Adolescent Idiopathic Scoliosis: A Minimum 10-Year Follow-Up

STUDY DESIGN Retrospective study. OBJECTIVES This study focused on patients with adolescent idiopathic scoliosis (AIS) who were followed up for more than 10 years, and assessed the influence of spinal balance on lumbar degenerative changes at distal unfused segments (DUS). SUMMARY OF BACKGROUND DATA Previous studies suggested that longer fusion segments may result in higher rates of occurrence of disc degeneration (DD) at unfused segments adjacent to the distal fused area. However, there are no existing studies that correlate the degree of DD to the location of lower instrumented vertebra (LIV) and the amount of the residual lumbar curve during the follow-up period. METHODS Radiologic measurements were recorded at the time of surgery, immediately after surgery, and 10 years after surgery. The Pfirrmann grading scale was used to rate the MR images of these patients. The presence of vertebral DD was also used to classify patients into DD+ and DD- groups. RESULTS 93 patients with AIS participated in this study. The average age at the time of surgery was 15.2 years; the average follow-up time was 154 months. DD was found in 45 patients (48%) and L5/S1 was the most common (40%) location in those patients. The L1 group experienced DD at a frequency of 34%, whereas the frequency increased with lower LIV placement. There was a significant difference between DD+ and DD- in age at the time of operation, the L4 tilt (pre Op. and post. 10 years), and the number of mobile segments. CONCLUSIONS Disc degeneration occurred in 48% of the patients at the time of postop. 10 years. Disc degeneration had a tendency to occur in patients with greater preoperative and postoperative 10 years L4 tilt angle and fewer mobile segments in the lower lumbar spine. LEVEL OF EVIDENCE Level III.

Three-Dimensional Analysis of Hemimetameric Segmental Shift in Congenital Scoliosis.

Study Design: This is a retrospective cohort study. Background: Hemimetameric segmental shift (HMMS) is defined as a hemivertebral deformation in which 2 or more hemivertebrae exist on both sides of the spine and are separated by at least 1 normal vertebra. Reports of HMMS are rare and based on simple anterior x-ray images. No reports have used 3-dimensional computed tomography (3D-CT) to analyze both the anterior and posterior elements. The objective of this study was to analyze the morphology and clinical features of HMMS 3 dimensionally. Methods: HMMS was confirmed in 32 (6.6%, 16 males and 16 females) of 483 patients diagnosed with congenital scoliosis at the study institution between 1998 and 2013. The average age at the first visit was 6 years and 3 months. 3D-CT imaging was performed for 30 patients older than 2 years (average age: 9 y and 8 mo) and used to classify cases according to posterior elements. Results: With regard to the number of hemivertebrae present, 21 patients had 2 hemivertebrae, 7 patients had 3 hemivertebrae, and 2 patients had 4 hemivertebrae. Patients with 2 hemivertebrae predominantly had hemivertebrae in the thoracolumbar spine. Patients were classified into 2 categories: malformation existing at an equal level in anterior and posterior sides (unison HMMS) and malformation existing at nonequal levels (discordant HMMS). Nine patients had unison HMMS and all of them had 2 hemivertebrae (average: 4.6 vertebrae). Twenty-one patients had discordant HMMS, with 12 having 2 hemivertebrae, 7 having 3 hemivertebrae, and 2 having 4 hemivertebrae. Conclusions: Through 3D-CT analysis, HMMS was categorized as unison or discordant. Discordant HMMS was observed in 21 of 30 (70%) patients and in all patients with >3 hemivertebrae. Diagnosing HMMS, whether unison or discordant, is clinically important and should be done with careful analysis of bone models and/or radiologic images to determine the correct spinal levels. Level of Evidence: Level IV—diagnostic study.

Corrective surgery for kyphosis in a case of Gaucher's disease without history of vertebral compression fractures

Introduction Gauchers disease is a congenital metabolic disorder characterized by the accumulation of glucocerebroside in the reticuloendothelial system. Its clinical manifestations include splenomegaly, osteopenia, and pathological fractures. Cases of patients with kyphotic deformities caused by pathological vertebral compression fractures associated with Gauchers disease are well reported. However, there has been no report regarding surgical treatment of kyphotic deformity caused by Gauchers disease without compression fractures. In the present report, we describe surgical treatment for kyphotic deformity caused by Gauchers disease without a past history of vertebral compression fractures. Case Report The patient was diagnosed with Gauchers disease at the age of 15 months. The patient was a 10-year-old girl with progressive kyphosis (84° between T6 and L3, with T12 as the apical vertebra) without compression fractures. Although the patient had been treated using a brace since the age of 3 years, the kyphosis progressed to the point where corrective surgery was required. We initially performed T3-L3 posterior spinal fusion, followed by anterior fusion 3 months later, which corrected the kyphosis to 35°. Postoperatively, the patient suffered fractures of the upper and lower extremities but did not have spinal fractures. Conclusions Two-stage anterior/posterior combined correction and fusion was performed in a patient with kyphotic deformity caused by Gauchers disease without compression fractures. Because of bone fragility in Gauchers disease, careful selection of the fusion range and postoperative therapy was necessary.

Pulmonary function and thoracic cage morphology during corrective cast treatment of early onset scoliosis

Historically, corrective casts have been used for the treatment of scoliosis. Over the years, this approach has evolved through countless modifications and improvements. However, while corrective casts are currently used for the treatment of Early Onset Scoliosis (EOS), treatment has been reported to have adverse constrictive effects on the thorax. To date, there have been no studies regarding the effects of corrective casts on pulmonary function and thoracic cage morphology. We hypothesized that cast treatment would have a negative marginal effect on pulmonary function and thoracic cage morphology post-treatment. The purpose of this study was to investigate the inference of the corrective cast treatment on pulmonary function and thoracic cage morphology in patients with EOS.

3 dimensional analysis of Hemimetameric Segmental Shift

Hemimetameric Segmental Shift (HMMS) is defined as a hemivertebral deformation in which two or more hemivertebra exists on both left and right sides of the spine, where the hemivertebras are separated by at least 1 normal vertebra. 3D-CT analysis done by Kawakami et al on congenital scoliosis patients proved the existence of mismatch among the anterior and posterior segments, where they coined this phenomenon as discordant anomaly. The purpose of this study is to analyze the morphology and determine clinical features of HMMS 3 dimensionally.

Reconstructive surgery for the post-hemiepiphysiodesis residual deformity in congenital scoliosis.

Spinal hemiepiphysiodesis is a well-known surgical procedure for correcting angular deformity in which the anterior and/or posterior epiphyseal plates of several vertebrae are fused on the convex side of the curvature with the expectation of spontaneous correction through continued growth of the concave side. We report on a patient with congenital scoliosis that had problems after hemiepiphysiodesis and required a salvage, reconstructive, antero-posterior combined surgery with instrumentation and osteotomy. After hemiepiphysiodesis, a marked fusion mass and a loss of bony landmarks made osteotomy and correction with a salvage surgery extremely difficult. We suggest that confirming the fusion area after hemiepiphysiodesis and determining the appropriate osteotomy site by 3D reconstruction images are important before salvage operations.