Browsing by Author "Machida, Masayoshi"

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    ItemOpen Access
    A comparison of the reliability and vulnerability of 3D sterEOS and 2D EOS when measuring the sagittal spinal alignment of patients with adolescent idiopathic scoliosis.
    (Spine deformity, 2022-09) Machida, Masayoshi; Rocos, Brett; Zabjek, Karl; Lebel, David E

    Purpose

    An essential component of making the diagnosis of adolescent idiopathic scoliosis (AIS) is standing anteroposterior and lateral radiographs. Two-dimensional (2D) radiographs inevitably fail to reflect every plane of the three-dimensional (3D) deformity in scoliosis. We have tested the hypothesis that there is no difference in the assessment of the sagittal plane deformity when measured with either 2D or 3D EOS radiography.

    Methods

    A retrospective radiographic analysis was performed on patients diagnosed with AIS, with subdivided into three groups according to the coronal angular deformity (mild group: 45°-69°, moderate group: 70°-89°, and severe group: 90° +). The sagittal parameters were compared between manual measurement with 2D sterEOS and those made using computer-aided 3D reconstruction.

    Results

    Fifty-two patients were included in each group. The inter-study reliability when measuring the thoracic Kyphosis (TK) and lumbar lordosis (LL) between the two study modalities was excellent in mild group (ICC: 0.90, 95% CI 0.82 ~ 0.94 and ICC: 0.84, 95% CI 0.74 ~ 0.91), excellent in TK and fair in LL in moderate group (ICC: 0.76, 95% CI 0.61 ~ 0.85 and ICC: 0.70, 95% CI 0.53 ~ 0.81), and fair in TK and LL in severe group, respectively (ICC: 0.74, 95% CI 0.57 ~ 0.84 and ICC: 0.65, 95% CI 0.46 ~ 0.84). A Bland-Altman plot showed proportional bias in TK measurements in each group and LL in moderate group, which means the measured value is underestimated in 2D method when the angle is small.

    Conclusion

    3D sterEOS is less vulnerable to the influence of coronal plane than 2D EOS in evaluating the sagittal spinal parameters of patients with a coronal deformity exceeding 70°.

    Level of evidence: 4

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    ItemOpen Access
    Costello syndrome-associated orthopaedic manifestations focussed on kyphoscoliosis: a case series describing the natural course.
    (Journal of pediatric orthopedics. Part B, 2023-07) Machida, Masayoshi; Rocos, Brett; Taira, Katsuaki; Nemoto, Naho; Oikawa, Noboru; Ohashi, Hirofumi; Machida, Masafumi; Kinoshita, Tomonori; Kamata, Yoshinori; Nakanishi, Kazuyoshi
    Costello syndrome (CS) is a rare genetic condition caused by a heterozygous mutation in the HRAS gene, with an estimated prevalence of 1: 300 000. Individuals with CS present with characteristic features including scoliosis, kyphosis, Chiari 1 malformation, and syringomyelia. The natural history of the spinal deformity associated with CS has been incompletely described. This case series describes the spinal deformity associated with CS and sets out a strategy for screening and treatment. The clinical records and spinal radiographs of nine consecutive CS patients encountered at a single centre were reviewed. Radiological assessments for the presence and progression of scoliosis were studied. Nine patients with confirmed CS were followed for a mean of 6.6 years. Five patients showed mild scoliosis. Two patients had lumbar kyphosis in addition to their scoliosis, and one showed scoliosis with proximal thoracic kyphosis. Three patients underwent investigation with MRI, one of which showed Chiari I malformation and a syrinx. One showed no change in the severity of their deformity over time. The remaining four patients showed a rate of increasing coronal deformity of 2.1° per year. There were no cases of rapid progression. All cases showed delayed skeletal maturity. The spinal deformity in CS appears to be slowly progressive. To identify those at risk of more rapid progression, brain and spine MRI should be carried out to exclude structural neurological abnormalities. Long follow-up is required for patients with spinal deformity in CS due to the delay in reaching skeletal maturity. Evidence level: 4.
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    ItemOpen Access
    Increased proximal vertebral rotation is associated with shoulder imbalance after posterior spinal fusion for severe adolescent idiopathic scoliosis.
    (Spine deformity, 2022-09) Machida, Masayoshi; Rocos, Brett; Lebel, David E; Zeller, Reinhard

    Purpose

    Residual shoulder imbalance is associated with suboptimal outcomes following the surgical correction of adolescent idiopathic scoliosis (AIS) including poor patient satisfaction. In this retrospective study, we evaluate the radiographic parameters and the relationship between the global and local indices of spinal alignment with shoulder balance pre- and postoperatively utilizing EOS imaging and 3D reconstruction.

    Methods

    A retrospective radiographic analysis was performed on patients with AIS, treated with posterior spinal fusion. Postoperative radiographs were obtained immediately following surgery, at 6 months and final follow-up over 2 years postoperatively. 3D Radiographic measurements included in the coronal plane radiographic shoulder height difference (RSHD), proximal thoracic Cobb angle (PT) and main thoracic Cobb (MT), in the sagittal plane T4-T12 kyphosis, T12-L5 lordosis, in the axial plane proximal thoracic (PT AVR) and main thoracic apical vertebral rotation (MT AVR).

    Results

    Sixty-six patients were included (63 females) with an average main thoracic curvature of 76 degrees. RSHD averaged 14 mm ± 14 preoperatively, -15 mm ± 12 postoperatively, -8.5 mm ± 11 at 6 months, and -8.3 mm ± 8.7 at final follow-up, respectively. Statistical analysis revealed a significant correlation between RSHD and proximal thoracic Cobb angle, between RSHD and proximal thoracic apical vertebral rotation (PTAVR) (r > 0.20, p < 0.05).

    Conclusion

    The significant correlation presented in this study suggests that PT Cobb angle and PT AVR are involved in postoperative shoulder imbalance.

    The level of evidence

    Level 4.
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    ItemOpen Access
    The Change of Asymptomatic Atlantoaxial Instability With Down Syndrome From Infant to Adolescent in Japanese Population: Minimum 10 Years Follow-Up.
    (Journal of pediatric orthopedics, 2024-11) Machida, Masayoshi; Rocos, Brett; Taira, Katsuaki; Nemoto, Naho; Oikawa, Noboru; Ohashi, Hirofumi; Aiba, Shutaro; Nakanishi, Kazuyoshi

    Background

    Although 10% to 60% of patients with Down syndrome (DS) develop atlantoaxial instability (AAI), clarifying the course of asymptomatic AAI may prevent unnecessary clinical interactions and investigations. This study investigates the radiographic changes observed in asymptomatic AAI associated with DS in Japanese children as they grow from infancy to adolescence over a minimum of 10 years.

    Methods

    A retrospective analysis of cervical radiographs acquired from asymptomatic patients with DS in both infancy and adolescence was carried out. Radiographic evaluation included measuring the atlantodental interval (ADI) and the space available for the cord (SAC). In neutral lateral cervical radiographs, AAI was defined as ADI >6 mm and SAC <14 mm.

    Results

    Two hundred thirty-nine patients were included. The mean follow-up was 12.8 years. ADI was 2.3 mm at initial evaluation and 2.7 mm at final evaluation (P<0.01) in a neutral position, 3.1 and 3.3 mm in flexion (P=0.18), and 1.7 and 2.1 mm in extension (P<0.01), respectively. SAC was 15.8 mm at initial evaluation and 20.9 mm at final evaluation (P<0.01) in neutral position, 15.6 and 20.7 mm in flexion (P<0.01), and 16.8 and 21.0 mm in extension (P<0.01), respectively. Forty-five patients (18.8%) showed evidence of AAI at the initial evaluation with 4 patients meeting the threshold for AAI at the final evaluation, one of which had os odontoideum. In contrast, of the 194 patients who did not have AAI at the initial evaluation, 3 (1.3%) developed AAI at the final evaluation. One of these with a normal den developed AAI at 13 years.

    Conclusions

    As 1 patient with a normal dens developed AAI at 13 years, we recommend screening for AAI with X-ray in infancy and adolescence regardless of the presence or absence of an os odontoideum.

    Evidence level

    Level IV.
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    ItemOpen Access
    The Prevalence of Scoliosis after Fontan Circulation Surgery Followed-Up to Adolescence.
    (Spine surgery and related research, 2024-03) Machida, Masayoshi; Rocos, Brett; Machida, Masafumi; Nomura, Koji; Nemoto, Naho; Oikawa, Noboru; Taira, Katsuaki

    Introduction

    The advancement of surgical techniques and perioperative management for congenital heart disease (CHD) has increased life expectancy. The surgical creation of the Fontan circulation maintains pulmonary blood flow without relying on an effective pump from the abnormal heart, relying on peripheral vascular resistance to maintain effective flow through the lungs. Unfortunately, this delicate mechanism is compromised when scoliosis restricts ventilation, leading to Fontan failure and a poor prognosis for life. This report describes the prevalence of scoliosis with Fontan completion surgery and the role of screening and surgical correction.

    Methods

    Ninety-six consecutive Japanese patients undergoing Fontan completion surgery for CHD between 2000 and 2017 were identified in our institutional records. The inclusion criterion was at least 7 years of follow-up after Fontan completion surgery, while the exclusion criteria were congenital, syndromic, and neuromuscular scoliosis. Radiographic and clinical parameters, including cardio-thoracic ratio (CTR) for cardiomegaly and cyanosis saturation, were compared between with and without scoliosis.

    Results

    There were 23 and 40 patients in the scoliosis and no scoliosis groups, respectively. The mean age at the final follow-up was 18.5 and 16.7 years in the scoliosis and no scoliosis groups, respectively (p=0.02). Mean CTR was 43.7% and 39.4% in the scoliosis and no scoliosis groups (p=0.016), and the mean saturation in room air at the final follow-up was 88.8% and 93.2%, respectively (p=0.036). There were no significant differences to clarify the risk factors with multivariate logistic regression analysis.

    Conclusions

    The prevalence of scoliosis with Fontan completion surgery was 36.5%. Screening for scoliosis is important for children with Fontan circulation surgery as part of their routine follow-up at least until they reach adolescence.Evidence Level: 4.
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    ItemOpen Access
    The use of three rods in correcting severe scoliosis.
    (Spine deformity, 2021-07) Rocos, Brett; Rioux-Trottier, Eliane; Machida, Masayoshi; Sigal, Amit; Kennedy, Jim; Lebel, David E; Zeller, Reinhard

    Purpose

    The three-rod technique, utilising a short apical concavity rod is an option to achieve controlled correction in severe scoliosis. We describe this technique, the complications encountered, and the long-term outcomes.

    Method

    All paediatric patients who had at least 2 years follow-up after undergoing corrective surgery for scoliosis ≥ 100° using 3 parallel rods were included. Radiographs were assessed to evaluate the correction and clinical records examined for any loss of correction, complications, revision procedures or neuromonitoring events.

    Results

    Twenty-five patients met the inclusion criteria. Four underwent prior anterior fusion to prevent crankshaft phenomenon. The mean angle of the deformity was 112.0° (range 100.3-137.1). Mean maximal kyphosis was 48.8° (range 11.4-78.8°) and mean curve flexibility 4.4% (range 0-37.0%). Intraoperative traction achieved an average of 70.4% (95% CI 56.6-84.1%). Nine patients (39%) showed a reduction in MEPs during definitive surgery. All returned to within 75% of baseline by the end of surgery. All patients had normal postoperative neurology. One patient underwent removal of hardware for late infection. The mean overall Cobb correction was 55.7° (95% CI 50.2-61.2°), equating to 50.2% (95% CI 44.9-55.4%) of the mean initial deformity. Thoracic kyphosis reduced by a mean of 18.2° (95% CI 12.8-23.6°).

    Conclusion

    Our series suggests that three-rod constructs are able to safely and effectively achieve 50% correction of severe scoliosis.