{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:20:12Z","timestamp":1760145612039,"version":"build-2065373602"},"reference-count":63,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2024,8,21]],"date-time":"2024-08-21T00:00:00Z","timestamp":1724198400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Caccomo Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>Background: Our study addresses the lack of consensus on measuring leg length discrepancy (LLD) after total hip arthroplasty (THA). We will assess the inter-observer variability and correlation between the five most commonly used LLD methods and investigate the use of trigonometric principles in overcoming the limitations of current techniques. Methods: LLD was measured on postoperative AP pelvic radiographs using five conventional methods. CT images created a 3D computer model of the pelvis and femur. The resulting models were projected onto a 2D, used to measure LLD by the five methods. The measurements were evaluated via Taguchi analysis, a statistical method identifying the process\u2019s most influential factors. The approach was used to assess the new trigonometric method. Results: Conventional methods demonstrated poor correlation. Methods referenced to the centers of the femoral heads were insensitive to LLD originating outside the acetabular cup. Methods referencing either the inter-ischial line or the inter-obturator foramina to the lesser trochanter were sensitive to acetabular and femoral components. Trigonometry-based measurements showed a higher correlation. Conclusions: Our results underscore clinicians\u2019 need to specify the methods used to assess LLD. Applying trigonometric principles was shown to be accurate and reliable, but it was contingent on proper radiographic alignment.<\/jats:p>","DOI":"10.3390\/bioengineering11080853","type":"journal-article","created":{"date-parts":[[2024,8,26]],"date-time":"2024-08-26T04:48:25Z","timestamp":1724647705000},"page":"853","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Comparative Study of Alternative Methods for Measuring Leg Length Discrepancy after Robot-Assisted Total Hip Arthroplasty"],"prefix":"10.3390","volume":"11","author":[{"given":"Hamad","family":"Nazmy","sequence":"first","affiliation":[{"name":"Department of Orthopaedic Surgery, University of Illinois at Chicago, Chicago, IL 60612, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0994-5724","authenticated-orcid":false,"given":"Giovanni","family":"Solitro","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics, LSU Health Shreveport, Shreveport, LA 71103, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Benjamin","family":"Domb","sequence":"additional","affiliation":[{"name":"American Hip Institute, 999 E. Touhy, Suite 450, Des Plaines, IL 60018, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Farid","family":"Amirouche","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, University of Illinois at Chicago, Chicago, IL 60612, USA"},{"name":"Orthopaedic and Spine Institute, Department of Orthopaedic Surgery, Northshore University Health System, an Affiliate of the University of Chicago Pritzker School of Medicine, 9669 Kenton Avenue, Skokie, IL 60076, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"513","DOI":"10.1016\/j.clinbiomech.2015.02.014","article-title":"Unilateral total hip replacement patients with symptomatic leg length inequality have abnormal hip biomechanics during walking","volume":"30","author":"Li","year":"2015","journal-title":"Clin. 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