Predictive Physical Manifestations for Progression of Scoliosis in Marfan Syndrome

Yuki Taniguchi, MD, PhD; Yoshitaka Matsubayashi, MD; So Kato, MD, PhD; Toru Doi, MD, PhD; Norifumi Takeda, MD, PhD; Hiroki Yagi, MD, PhD; Ryo Inuzuka, MD, PhD; Yasushi Oshima, MD, PhD; Sakae Tanaka, MD, PhD

Disclosures

Spine. 2021;46(15):1020-1025. 

In This Article

Materials and Methods

Data Source and Patients

We retrospectively obtained the data from the prospective cohort of the Marfan syndrome clinic at our institute for a total of 75 months, from January 1, 2014 to March 31, 2020. Among the patients who visited the Orthopedic Department of the Marfan Syndrome Clinic, 163 Japanese patients were diagnosed with Marfan syndrome according to the revised Ghent nosology.[9] Every patients' systemic score was calculated at their first visit to the orthopedic department. Of these patients, we excluded patients whose systemic score was calculated under the age of 10 because physical features defined in the systemic score are sometimes difficult to judge in children with Marfan syndrome.

Collected Physical Features

Collected physical features were those described in the systemic score, which was defined in the revised Ghent nosology[9] (Table 1). Among manifestations described in the systemic score, we excluded "myopia" and "reduced upper segment/lower segment" from this study and investigated other factors. This is because the results of the visual acuity test were not available for most of the patients, and the cutoff of the upper segment/lower segment ratio in Asians has not yet been determined.[9] The presence of dural ectasia was judged when computed tomography or magnetic resonance images of the lumbosacral spine were available. Mitral valve prolapse was evaluated only in patients whose transthoracic echocardiography was available. The systemic score of each patient was evaluated and calculated by a single surgeon. (Y.T.).

Evaluation of Spinal Deformity

In all patients, posterior-anterior and lateral whole spine X-rays in the standing position at final follow-up were evaluated, except for 11 patients whose lateral whole spine X-rays were not available. To eliminate the impact of growth potential, which is known to affect the progression of scoliosis, we excluded patients whose X-ray of the final follow-up was taken before 15 years of age. Although one point is assigned in the systemic score when scoliosis with Cobb angle ≥ 20° or exaggerated thoracolumbar kyphosis is present, we classified the degree of scoliosis into four categories: "not apparent" (Cobb <10°), "mild" (10° ≤ Cobb angle < 25°), "moderate" (25° ≤ Cobb angle < 40°), and "severe" (40° ≤ Cobb angle or surgery conducted) according to the treatment strategy for scoliosis. When Cobb angle exceeds 25°, brace treatment can be a choice in patients during periods of growth, and when it exceeds 40°, surgery can be indicated in patients with Marfan syndrome at our institute. The posterior-anterior whole spine radiographs in the standing position were also used for the evaluation of protrusio acetabuli.

Statistical Analysis

The chi-square test was used to compare categorical data. Student t test was used to compare continuous variables. A multivariate logistic regression analysis was performed to determine the risk factors associated with the progression of scoliosis. We treated patients whose data on dural ectasia or mitral valve prolapse were unavailable as missing values. The threshold for significance was set at P < 0.05. All statistical analyses were performed using JMP Pro (version 15.0.0, SAS Institute Inc, Cary, NC).

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