{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T20:06:59Z","timestamp":1772222819589,"version":"3.50.1"},"reference-count":25,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2025,7,14]],"date-time":"2025-07-14T00:00:00Z","timestamp":1752451200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100013348","name":"Innosuisse - Schweizerische Agentur f\u00fcr Innovationsf\u00f6rderung","doi-asserted-by":"publisher","award":["47195.1 IP-LS"],"award-info":[{"award-number":["47195.1 IP-LS"]}],"id":[{"id":"10.13039\/501100013348","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Optical 3D surface scanning has emerged as a valuable modality for assessing spinal deformity in patients with scoliosis, avoiding radiation exposure. However, correlations remain moderate between deformation parameters obtained from radiographs and those estimated solely from the 3D back surface, referred to as the \u201cback-shape-to-spine\u201d approach. To improve the accuracy with which the back-shape-to-spine approach can estimate the internal spinal alignment (ISL) from 3D surface scanning, deeper understanding is required of the effect of scoliosis on the back shape. The PCdare software, which enables semi-automatic registration of 3D surface scans with the corresponding biplanar radiographs, has been used by students in a previous study to validate study protocols, generate references for estimated ISL, and evaluate correlations between the spinous process line (SPL) and ISL. This study explored the potential of the PCdare software to investigate the underlying relationship between the ISL and the 3D back shape, conducted a comparative study with 3 study protocols, and conducted an inter- and intrarater reliability (IIR) study with 6 clinicians and 10 students as raters to evaluate the applicability of PCdare when used by students. The comparative study involved 252 patients with idiopathic scoliosis from 3 studies that compared the back-shape-to-spine approach with radiography. The quality of study protocols and the relationship between internal spinal alignment and 3D back shape were both investigated by evaluating the posture alignment errors and correlations between Cobb angles. The inter- and intrarater reliability study involved 7 patients with idiopathic scoliosis and was conducted using PCdare and validated with PACS. The median Cobb angle difference (interquartile range: IQR) between students and clinicians (interclass) was 0.06\u00b0 (1.5\u00b0). The ICC [confidence interval] between Cobb angles (interrater) was 0.94 [0.7,0.98]. The median absolute Cobb angle difference (IQR) between 3 repetitions (intrarater) were 4.2\u00b0 (5.3\u00b0) or lower. The median Cobb angle difference (IQR) between PCdare and PACS was 1.5\u00b0 (8.4\u00b0) for clinicians and 1.4\u00b0 (6.9\u00b0) for students, whereas the corresponding correlation [confidence interval] was 0.94 [0.92,0.96] and 0.95 [0.93,0.96], respectively. The median RMSE (median SD) of posture alignment error ranged between 8.1\u2009mm (5.2\u2009mm) and 5\u2009mm (3.5\u2009mm), whereas the median PCC (IQR) between ISL and SPL ranged between 0.64 (0.58) and 0.99 (0.02). Students achieve outcomes comparable to clinicians when using PCdare, which underlines its reliability and ease of use. In addition, the application of PCdare to examine the quality of study protocols revealed the necessity of markers and posture alignment and delivered correlation coefficients for the relationship between internal spinal alignment and 3D back shape. These findings highlight the potential of the PCdare software to advance the non-ionizing assessment of spinal deformities and thus improve understanding of scoliosis.<\/jats:p>","DOI":"10.1371\/journal.pone.0321429","type":"journal-article","created":{"date-parts":[[2025,7,14]],"date-time":"2025-07-14T17:29:06Z","timestamp":1752514146000},"page":"e0321429","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Investigating the relationship between internal spinal alignment and back shape in patients with scoliosis using PCdare: A comparative, reliability and validation study"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8763-5003","authenticated-orcid":true,"given":"Mirko","family":"Kaiser","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-2670-2657","authenticated-orcid":true,"given":"Meby","family":"Mudavamkunnel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"Bertsch","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christoph J.","family":"Laux","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ines","family":"Unterfrauner","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Florian","family":"Wanivenhaus","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David E.","family":"Bauer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thorsten","family":"Jentzsch","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexandra","family":"Stauffer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mazda","family":"Farshad","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0525-2197","authenticated-orcid":true,"given":"Sasa","family":"Cukovic","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2025,7,14]]},"reference":[{"key":"pone.0321429.ref001","doi-asserted-by":"crossref","DOI":"10.1097\/BPO.0000000000001350","article-title":"The natural history of adolescent idiopathic scoliosis","volume":"39","author":"SL Weinstein","year":"2019","journal-title":"J Pediatr Orthop"},{"issue":"10","key":"pone.0321429.ref002","doi-asserted-by":"crossref","first-page":"3366","DOI":"10.1007\/s00586-016-4747-2","article-title":"Incidence of cancer in adolescent idiopathic scoliosis patients treated 25 years previously","volume":"25","author":"A Simony","year":"2016","journal-title":"Eur Spine J"},{"issue":"12","key":"pone.0321429.ref003","doi-asserted-by":"crossref","first-page":"3123","DOI":"10.1007\/s00586-020-06573-7","article-title":"Cancer and mortality risks of patients with scoliosis from radiation exposure: a systematic review and meta-analysis","volume":"29","author":"F-J Luan","year":"2020","journal-title":"Eur Spine J"},{"issue":"3","key":"pone.0321429.ref004","doi-asserted-by":"crossref","first-page":"526","DOI":"10.1007\/s00586-018-05876-0","article-title":"Is rasterstereography a valid noninvasive method for the screening of juvenile and adolescent idiopathic scoliosis?","volume":"28","author":"T Bassani","year":"2019","journal-title":"Eur Spine J"},{"issue":"5","key":"pone.0321429.ref005","doi-asserted-by":"crossref","first-page":"1883","DOI":"10.3390\/s22051883","article-title":"Acute effects of self-correction on spine deviation and balance in adolescent girls with idiopathic scoliosis","volume":"22","author":"L Marin","year":"2022","journal-title":"Sensors (Basel)"},{"issue":"1","key":"pone.0321429.ref006","doi-asserted-by":"crossref","first-page":"9678","DOI":"10.1038\/s41598-019-46246-0","article-title":"Three-dimensional depth sensor imaging to identify adolescent idiopathic scoliosis: a prospective multicenter cohort study","volume":"9","author":"T Kokabu","year":"2019","journal-title":"Sci Rep"},{"key":"pone.0321429.ref007","volume-title":"Pcdare Software Registers 3d Back Surface with Biplanar Radiographs: Application to Patients with Scoliosis","author":"M Kaiser","year":"2024"},{"key":"pone.0321429.ref008","article-title":"alidation of internal parameters of adolescent idiopathic scoliosis evaluated using ScolioSIM solution - preliminary results","volume-title":"VPH2022","author":"S Cukovic"},{"issue":"2","key":"pone.0321429.ref009","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.jcm.2016.02.012","article-title":"A guideline of selecting and reporting intraclass correlation coefficients for reliability research","volume":"15","author":"TK Koo","year":"2016","journal-title":"J Chiropr Med"},{"issue":"3","key":"pone.0321429.ref010","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.tjem.2018.08.001","article-title":"User\u2019s guide to correlation coefficients","volume":"18","author":"H Akoglu","year":"2018","journal-title":"Turk J Emerg Med"},{"key":"pone.0321429.ref011"},{"key":"pone.0321429.ref012","doi-asserted-by":"crossref","first-page":"12","DOI":"10.21037\/asj-21-105","article-title":"Inter- and intra-reliability of Cobb angle measurement in pediatric scoliosis using PACS (picture archiving and communication systems methods) for clinicians with various levels of experience","volume":"3","author":"C Lucasti","year":"2023","journal-title":"AME Surg J"},{"issue":"1","key":"pone.0321429.ref013","doi-asserted-by":"crossref","first-page":"304","DOI":"10.14245\/ns.1938260.130","article-title":"Oxford cobbometer versus computer assisted-software for measurement of cobb angle in adolescent idiopathic scoliosis","volume":"17","author":"T Elfiky","year":"2020","journal-title":"Neurospine"},{"issue":"12","key":"pone.0321429.ref014","doi-asserted-by":"crossref","first-page":"3035","DOI":"10.1007\/s00586-019-06115-w","article-title":"Evaluation of a computer-aided method for measuring the Cobb angle on chest X-rays","volume":"28","author":"Y Pan","year":"2019","journal-title":"Eur Spine J"},{"issue":"1","key":"pone.0321429.ref015","doi-asserted-by":"crossref","first-page":"14576","DOI":"10.1038\/s41598-023-41821-y","article-title":"Automatic measurement of the Cobb angle for adolescent idiopathic scoliosis using convolutional neural network","volume":"13","author":"Y Maeda","year":"2023","journal-title":"Sci Rep"},{"issue":"1","key":"pone.0321429.ref016","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s13018-018-0928-5","article-title":"Measurement of scoliosis Cobb angle by end vertebra tilt angle method","volume":"13","author":"J Wang","year":"2018","journal-title":"J Orthop Surg Res"},{"key":"pone.0321429.ref017","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1186\/1471-2474-15-33","article-title":"Reliability and reproducibility analysis of the Cobb angle and assessing sagittal plane by computer-assisted and manual measurement tools","volume":"15","author":"W Wu","year":"2014","journal-title":"BMC Musculoskelet Disord"},{"issue":"12","key":"pone.0321429.ref018","article-title":"Reliability and accuracy analysis of a new semiautomatic radiographic measurement software in adult scoliosis","volume":"36","author":"C-E Aubin","year":"2011","journal-title":"Spine (Phila Pa 1976)"},{"issue":"10","key":"pone.0321429.ref019","doi-asserted-by":"crossref","first-page":"1587","DOI":"10.1007\/s00586-007-0401-3","article-title":"Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools","volume":"16","author":"M Gstoettner","year":"2007","journal-title":"Eur Spine J"},{"issue":"1","key":"pone.0321429.ref020","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1007\/s43390-021-00398-0","article-title":"Intra- and inter-observer reliability of Cobb angle measurements in patients with adolescent idiopathic scoliosis","volume":"10","author":"FG Prestigiacomo","year":"2022","journal-title":"Spine Deform"},{"issue":"3","key":"pone.0321429.ref021","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1016\/j.jspd.2014.02.006","article-title":"Intra- and interobserver reliability of the cobb angle-vertebral rotation angle-spinous process angle for adolescent idiopathic scoliosis","volume":"2","author":"ACY Chan","year":"2014","journal-title":"Spine Deform"},{"key":"pone.0321429.ref022","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.isurg.2022.01.001","article-title":"The smartphone scoliosis screening software for measuring the Cobb angle of adolescent idiopathic scoliosis: a reliability study","volume":"1","author":"Y Song","year":"2022","journal-title":"Intell Surgery"},{"key":"pone.0321429.ref023","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.hkpj.2017.01.003","article-title":"Reliability of novice physiotherapists for measuring Cobb angle using a digital method","volume":"37","author":"P Suwannarat","year":"2017","journal-title":"Hong Kong Physiother J"},{"issue":"1","key":"pone.0321429.ref024","doi-asserted-by":"crossref","DOI":"10.5812\/mejrh.111360","article-title":"Computer-aided measurement system using image processing for measuring cobb angle in scoliosis","volume":"9","author":"N Moftian","year":"2021","journal-title":"Middle East J Rehabil Health Stud"},{"issue":"6","key":"pone.0321429.ref025","doi-asserted-by":"crossref","first-page":"3817","DOI":"10.3390\/app13063817","article-title":"Vertebral center points locating and cobb angle measurement based on deep learning","volume":"13","author":"Z Zhou","year":"2023","journal-title":"Appl Sci"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0321429","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,7,14]],"date-time":"2025-07-14T17:29:11Z","timestamp":1752514151000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0321429"}},"subtitle":[],"editor":[{"given":"Mohammad Amin","family":"Fraiwan","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2025,7,14]]},"references-count":25,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,7,14]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0321429","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2025.03.09.25323630","asserted-by":"object"}]},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,14]]}}}