{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T12:06:08Z","timestamp":1791893168460,"version":"4.3.4"},"reference-count":37,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"1","license":[{"start":{"date-parts":[[2020,8,11]],"date-time":"2020-08-11T00:00:00Z","timestamp":1597104000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":["Operative Surg.","ONSURG"],"published-print":{"date-parts":[[2021,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>S2-alar-iliac (S2AI) screws improve stability across the lumbosacral junction in spinopelvic fixation procedures by crossing the cortical surfaces of the sacroiliac joint (SIJ), thereby increasing the biomechanical strength of the instrumentation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>OBJECTIVE<\/jats:title>\n                    <jats:p>To investigate the durability and failure types of S2AI screws after spinopelvic reconstruction surgery.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>A single-center, single-surgeon consecutive series of patients who underwent spinopelvic fixation using bilateral S2AI screws with a\u00a0\u22651-yr follow-up and at least 1 postoperative computed tomographic scan were retrospectively reviewed. Patient characteristics, radiographic parameters, operative data, clinical outcomes, and complications were analyzed.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>In total, 312 S2AI screws in 156 patients were evaluated (mean follow-up, 26.1 mo; range 12-71 mo). There were no significant differences in screw diameter, length, or insertion angle between right-side and left-side screws. Visual analogue scale scores for back pain, ambulatory status, and Oswestry Disability Index scores significantly improved. A total of 10 patients (3.2%) experienced SIJ pain after S2AI screw installation. SIJ pain improved in 8 of them following SIJ block. In total, 7 screws (2.2%) showed partial periscrew lucency. Set screw dislodgement occurred in 7 screws (2.2%). Screw fracture occurred in 6 screws (1.9%): 5 neck fractures and 1 shaft fracture. A total of 5 patients (1.6%) underwent revision surgery for S2AI screw failure. Distal device (L4-pelvis region) breakage occurred in 5 patients.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSION<\/jats:title>\n                    <jats:p>The radiographic and clinical outcomes of S2AI screw fixation were acceptable. However, S2AI screw fixation has several drawbacks, including screw fracture and dislodgement of the set screw. SIJ irritation symptoms after S2AI screw fixation occurred with considerable frequency.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ons\/opaa251","type":"journal-article","created":{"date-parts":[[2020,8,11]],"date-time":"2020-08-11T18:42:18Z","timestamp":1597171338000},"page":"91-97","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":27,"title":["Durability and Failure Types of S2-Alar-Iliac Screws: An Analysis of 312 Consecutive Screws"],"prefix":"10.1227","volume":"20","author":[{"given":"Seung-Jae","family":"Hyun","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, Spine Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jong-myung","family":"Jung","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Spine Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ki-Jeong","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Spine Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tae-Ahn","family":"Jahng","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Spine Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2021,1]]},"reference":[{"issue":"8","key":"bib1-20260601","doi-asserted-by":"crossref","first-page":"824","DOI":"10.1097\/00007632-198610000-00017","article-title":"Fusion to the sacrum for nonparalytic scoliosis in the adult","volume":"11","author":"Balderston","year":"1986","journal-title":"Spine (Phila Pa 1976)"},{"issue":"2","key":"bib2-20260601","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1097\/00002517-199106000-00002","article-title":"Management of adult spinal deformity with combined anterior-posterior arthrodesis and Luque\u2013Galveston instrumentation","volume":"4","author":"Boachie-Adjei","year":"1991","journal-title":"J Spinal Disord"},{"issue":"7","key":"bib3-20260601","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1097\/00007632-200204010-00017","article-title":"Outcome and complications of long fusions to the sacrum in adult spine deformity: Luque\u2013Galveston, combined iliac and sacral screws, and sacral fixation","volume":"27","author":"Emami","year":"2002","journal-title":"Spine (Phila Pa 1976)"},{"issue":"20","key":"bib4-20260601","doi-asserted-by":"crossref","first-page":"2329","DOI":"10.1097\/01.brs.0000238968.82799.d9","article-title":"Pseudarthrosis in long adult spinal deformity instrumentation and fusion to the sacrum: prevalence and risk factor analysis of 144 cases","volume":"31","author":"Kim","year":"2006","journal-title":"Spine (Phila Pa 1976)"},{"issue":"18","key":"bib5-20260601","doi-asserted-by":"crossref","first-page":"1996","DOI":"10.1097\/01.brs.0000138272.54896.33","article-title":"Long adult deformity fusions to L5 and the sacrum. 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