Assessment of Early Juvenil Idiopathic Scoliosis: Clinical Trial for the Evaluation of A School-Based Screening Protocol

This study aims to evaluate the effectiveness of clinical tests currently in use for the diagnosis of JIS, through a survey, carried out in secondary schools in the province of Palermo, in order to standardize a school screening protocol that could be extended to the whole regional territory. The adolescents underwent a specialist physiatric examination in their classrooms; moreover three screening tests have been administred: Adams test, Bunnel Inclinometer and Plumb line test. In case of single positivity to one of the three tests, the adolescent underwent to radiography of the whole column. Then we examined the sensitivity and diagnostic specicity of the Adams or inclinometer test, respectively: 56.3% and 92.7%. On the other hand, the positivity to at least one between inclinometer or plumb line sensitivity was higher than the specicity: 91.3% versus 80.8%. The same happened for the positivity to at least one test between Adams index or plumb line test, which showed a sensitivity of 95.2% compared to a specicity of 81.5%. Finally, taking into consideration patients with triple test positivity, a clear increase in specicity compared to sensitivity was demonstrated, reaching 99.7% Performing a single test cannot be considered a sucient tool aiming to detect potential scoliotic subjects. To conclude, an effective screening program can reduce health care expenditure related to specialist medical examinations as well as unnecessary instrumental exams such as X-rays.

the other hand, the positivity to at least one between inclinometer or plumb line sensitivity was higher than the speci city: 91.3% versus 80.8%. The same happened for the positivity to at least one test between Adams index or plumb line test, which showed a sensitivity of 95.2% compared to a speci city of 81.5%. Finally, taking into consideration patients with triple test positivity, a clear increase in speci city compared to sensitivity was demonstrated, reaching 99.7% Performing a single test cannot be considered a su cient tool aiming to detect potential scoliotic subjects. To conclude, an effective screening program can reduce health care expenditure related to specialist medical examinations as well as unnecessary instrumental exams such as X-rays.

Background Section
Juvenile Idiopathic Scoliosis (JIS) is a complex structural deformity of the spinal column on the three planes of space; on the frontal plane a lateral bending movement occurs, as well as an alteration of the curves on the sagittal plane, most often causing a curve inversion; on the axial plane a rotational movement still occurs [1-3].
Classically, JIS does not recognize a well-known cause and probably not even a singular cause.
Nevertheless, considering the etiopathogenetic mechanisms, vertebral deformity, caused by JIS, can be de ned as a sign of a complex syndrome with a multifactorial etiology [4][5]. Possible etiological factors such as female sex, familiarity, rst born being, genetic background, biomechanical or neurological disorders, aberrant hormones functioning such as growth hormone and melatonin, body schema disorders are mentioned in several studies. Behind this etiological heterogeneity, clear scenarios of autosomal dominant or autosomal recessive transmission are described together with a multifactorial heredity background [6].
According to recent literature, the prevalence rate varies from 0.47-5.2%, though it is commonly accepted 2-3% occurrence of the disease in the general population, with a female to male ratio of 4:1 [7].
According to Society On Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT), a Cobb's Angle greater than or equal to 10° radiographic degrees de nes scoliosis. Above 30° Cobb's Angle degrees the probability of anatomical damage increases signi cantly [8].
JIS may occur at any time of growth development. However, Tanner demonstrates that growth spurt does not proceed with a linear pattern; actually there are two periods of rapid growth, from birth to three years and during the pubertal crisis. This latter occurs at two different times in both sexes.
In fact, in females, the pubertal crisis coincides with or precedes the beginning of the development of the breast and pubic hair (about 11 years old), with a peak around the age of 12 and a term at the age of 14.
The presence of menarche indicates a reduced risk in scoliosis progression. Conversely, in males it appears about two years after the appearance of pubic hair, with a peak around 16 years of age.
An early diagnosis correlates with less invasive conservative treatments, preventing surgery and avoiding respiratory, psychological and social complications that characterize the later stages of the disease [9].
Nowadays in Sicily, no early diagnosis program throughout a school-based screening process for JIS is validated.
This study aims to evaluate the effectiveness of clinical tests currently in use for the diagnosis of JIS, through a survey, carried out in secondary schools in the province of Palermo, in order to standardize a school screening protocol that could be extended to the whole regional territory.

Methods
This Quasi-experimental clinical trial was conducted by the Rehabilitation and Epidemiology and Preventive Medicine Hospital Units University of Palermo.
Between February 2019 and January 2020 preadolescents, that differ from urban area and socio-cultural status and attending eight rst-grade secondary schools of the Province of Palermo were recruited.
Experimenters went to the schools and provided detailed information and behavioral norms for effective prevention of JIS.
Subsequently, the adolescents, whose parents had signed their informed consent, underwent a specialist physiatric examination in their classrooms; moreover three screening tests have been administred: Adams test, Bunnel Inclinometer and Plumb line test.
Adams test: ex the patient's torso forward, with the head bent, arms relaxed and lower limbs extended: in this way, the torso is highlighted and the torso must be measured at the point where there is the greatest difference in height between the two sides. [10] Bunnel's Inclinometer: uses an inclinometer (scoliometer) to measure the tines and determine the angle of rotation of the trunk. [10] Plumb line test: patient standing in correct posture with a straight gaze, position the tangent line until it reaches the intergluteal fold in order to obtain a true reference vertical for measurements. From the plumb line, once immobile, it is possible to calculate the distance up to the three reference points C7-D12-L3. The values considered normal for kyphosis are given by the sum of the arrow of C7 and L3 up to 90 mm, and at L3 level up to 55 mm. Values above 90 mm and 55 mm should lead to a specialist investigation according to the latest scienti c ISICO screening protocol [10], however, there is no unanimous consensus.
In case of single positivity to one of the three screening tests, the adolescent underwent to further instrumental diagnostic investigation: radiography of the whole column, under load, in two projections The parameters taken into consideration by our study for the evaluation of the e cacy of the diagnostic tests examined were [ Table I]: -Sensitivity: = a/(a + c), i.e. the probability that a patient testing positive; -Speci city = d/(b + d), i.e. the probability of a healthy person testing negative; -LR + is the ratio between the probability that a patient is positive and the probability that a healthy person is positive. In other words, in the case of a positive test result, LR + is times more likely that the subject is sick than healthy.
-LR-is the ratio between the probability that a patient is negative and the probability that a healthy person is negative. In other words, in the case of a negative test result, LR-is times more likely that the subject is ill than healthy (Table II):  Associating the variables, a total of 81 adolescents (43.5%) were positive for the Adams test, 78 (41.9%) for the inclinometer and 117 (62.9%) for the plumb line (Fig. 1).
Interestingly, after the radiographic study, we observed that, among the 186 patients tested positive to at least one screening test, 126 of them (66.7%) had an angle of Cobb greater than 10° and therefore considered affected by JIS; moreover 46 (24.7%) adolescents had an angle greater than 8 and less than 10.
Analyzing and cross-referencing the data described above, we experienced that the Adams test sensitivity and speci city were of 50.8% and 94.4% respectively with a positive predictive value of 79%, representing, among the three tests performed, the one with the highest speci city, sensitivity and positive predictive value.
Bunnel's test showed a sensitivity of 46%, a speci city of 93.4% and a positive predictive value of 74.4%.
Then we examined the sensitivity and diagnostic speci city of the group of positive subjects to at least one Adams or inclinometer test, respectively: 56.3% and 92.7%.
On the other hand, the positivity to at least one between inclinometer or plumb line sensitivity was higher than the speci city: 91.3% versus 80.8%.
The same happened for the positivity to at least one test between Adams index or plumb line test, which showed a sensitivity of 95.2% compared to a speci city of 81.5%. [