{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T04:46:44Z","timestamp":1791953204956,"version":"4.3.4"},"reference-count":27,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T00:00:00Z","timestamp":1760400000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T00:00:00Z","timestamp":1760400000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100009331","name":"Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support","doi-asserted-by":"crossref","award":["YGLX202313"],"award-info":[{"award-number":["YGLX202313"]}],"id":[{"id":"10.13039\/501100009331","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Beijing Natural Science Foundation","award":["L222063"],"award-info":[{"award-number":["L222063"]}]},{"DOI":"10.13039\/501100005090","name":"Beijing Nova Program","doi-asserted-by":"crossref","award":["20230484279"],"award-info":[{"award-number":["20230484279"]}],"id":[{"id":"10.13039\/501100005090","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Arthroplasty"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Although robot-assisted TKA improves alignment accuracy, the understanding of soft tissue stiffness remains limited. This study aimed to investigate the impact of preoperative and constitutional alignment on the stiffness of knee compartments during robot-assisted TKA.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We included 151 patients who underwent primary robot-assisted TKA between May 2021 and May 2022. A digital joint-tensioning device was used intraoperatively to apply stepwise increasing tension (30\u201390 N) to the medial and lateral knee compartments. The device measured corresponding gap changes at 0\u00b0, 10\u00b0, and 90\u00b0 of flexion. Linear regression was used to analyze the relationship between gap changes and applied tension, and the regression slope (K value) was used to compare stiffness between compartments. Preoperative factors, including hip-knee-ankle angle and Coronal Plane Alignment of the Knee (CPAK) subtypes, were assessed for their influence on stiffness.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      There were significant differences in stiffness (K values) between medial and lateral compartments, particularly at higher flexion. The medial compartment generally showed greater stiffness. The medial-to-lateral stiffness ratio increased with greater varus alignment. Significant differences in K\n                      <jats:sub>M<\/jats:sub>\n                      \/K\n                      <jats:sub>L<\/jats:sub>\n                      ratios were found among CPAK subtypes at 0\u00b0 and 10\u00b0 flexion.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This study introduced gap-tension regression for assessing soft tissue stiffness in robot-assisted TKA and showed that stiffness is influenced by preoperative and constitutional alignment. Varus alignment was associated with higher medial-to-lateral stiffness, and CPAK subtypes showed distinct stiffness patterns. These findings may help optimize soft tissue balancing and improve outcomes in TKA.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s42836-025-00338-7","type":"journal-article","created":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T02:27:21Z","timestamp":1760408841000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Impact of preoperative and constitutional alignment on soft tissue stiffness in robot-assisted total knee arthroplasty"],"prefix":"10.1186","volume":"7","author":[{"given":"Zhaolun","family":"Wang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mingxue","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yixin","family":"Zhou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yunfeng","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dejin","family":"Yang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chengshuai","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hao","family":"Tang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yong","family":"Huang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2025,10,14]]},"reference":[{"key":"338_CR1","doi-asserted-by":"crossref","DOI":"10.1155\/2014\/628695","volume":"2014","author":"KA Gustke","year":"2014","unstructured":"Gustke KA, Golladay GJ, Roche MW, Elson LC, Anderson CR. Primary TKA Patients with Quantifiably Balanced Soft-Tissue Achieve Significant Clinical Gains Sooner than Unbalanced Patients. Adv Orthop. 2014;2014:628695.","journal-title":"Adv Orthop"},{"issue":"7s","key":"338_CR2","doi-asserted-by":"publisher","first-page":"S195","DOI":"10.1016\/j.arth.2019.03.036","volume":"34","author":"GJ Golladay","year":"2019","unstructured":"Golladay GJ, Bradbury TL, Gordon AC, Fernandez-Madrid IJ, Krebs VE, Patel PD, et al. Are patients more satisfied with a balanced total knee arthroplasty? J Arthroplasty. 2019;34(7s):S195\u2013200.","journal-title":"J Arthroplasty"},{"key":"338_CR3","doi-asserted-by":"publisher","first-page":"315","DOI":"10.1097\/00003086-200111000-00041","volume":"392","author":"TK Fehring","year":"2001","unstructured":"Fehring TK, Odum S, Griffin WL, Mason JB, Nadaud M. Early failures in total knee arthroplasty. Clin Orthop Relat Res. 2001;392:315\u20138.","journal-title":"Clin Orthop Relat Res"},{"issue":"5","key":"338_CR4","doi-asserted-by":"publisher","first-page":"955","DOI":"10.1016\/j.arth.2013.10.020","volume":"29","author":"KA Gustke","year":"2014","unstructured":"Gustke KA, Golladay GJ, Roche MW, Elson LC, Anderson CR. A new method for defining balance: promising short-term clinical outcomes of sensor-guided TKA. J Arthroplasty. 2014;29(5):955\u201360.","journal-title":"J Arthroplasty"},{"issue":"1","key":"338_CR5","doi-asserted-by":"publisher","first-page":"e0050","DOI":"10.2106\/JBJS.RVW.19.00050","volume":"8","author":"A Siddiqi","year":"2020","unstructured":"Siddiqi A, Smith T, McPhilemy JJ, Ranawat AS, Sculco PK, Chen AF. Soft-tissue balancing technology for total knee arthroplasty. 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Is there a force target that predicts early patient-reported outcomes after kinematically aligned TKA? Clin Orthop Relat Res. 2019;477(5):1200\u20137.","journal-title":"Clin Orthop Relat Res"},{"issue":"5","key":"338_CR9","doi-asserted-by":"publisher","first-page":"1671","DOI":"10.1007\/s00167-018-5314-7","volume":"27","author":"SJ Song","year":"2019","unstructured":"Song SJ, Kang SG, Lee YJ, Kim KI, Park CH. An intraoperative load sensor did not improve the early postoperative results of posterior-stabilized TKA for osteoarthritis with varus deformities. Knee Surg Sports Traumatol Arthrosc. 2019;27(5):1671\u20139.","journal-title":"Knee Surg Sports Traumatol Arthrosc"},{"issue":"7","key":"338_CR10","doi-asserted-by":"publisher","first-page":"2238","DOI":"10.1007\/s00167-018-5164-3","volume":"27","author":"WA Manning","year":"2019","unstructured":"Manning WA, Blain A, Longstaff L, Deehan DJ. 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Intra-operative laxity and balance impact 2-year pain outcomes in TKA: a prospective cohort study. Knee Surg Sports Traumatol Arthrosc. 2023;31(12):5535\u201345.","journal-title":"Knee Surg Sports Traumatol Arthrosc"},{"issue":"12","key":"338_CR13","doi-asserted-by":"publisher","first-page":"2087","DOI":"10.1007\/s00402-021-04173-8","volume":"141","author":"J Shatrov","year":"2021","unstructured":"Shatrov J, Murphy GT, Duong J, Fritsch B. Robotic-assisted total knee arthroplasty with the OMNIBot platform: a review of the principles of use and outcomes. Arch Orthop Trauma Surg. 2021;141(12):2087\u201396.","journal-title":"Arch Orthop Trauma Surg"},{"issue":"4","key":"338_CR14","doi-asserted-by":"publisher","first-page":"953","DOI":"10.1002\/ksa.12118","volume":"32","author":"B Ollivier","year":"2024","unstructured":"Ollivier B, Wakelin E, Plaskos C, Vandenneucker H, Luyckx T. Widening of tibial resection boundaries increases the rate of femoral component valgus and internal rotation in functionally aligned TKA. Knee Surg Sports Traumatol Arthrosc. 2024;32(4):953\u201362.","journal-title":"Knee Surg Sports Traumatol Arthrosc"},{"key":"338_CR15","doi-asserted-by":"publisher","first-page":"171","DOI":"10.1097\/01.blo.0000145555.34318.46","volume":"427","author":"RC Wasielewski","year":"2004","unstructured":"Wasielewski RC, Galat DD, Komistek RD. An intraoperative pressure-measuring device used in total knee arthroplasties and its kinematics correlations. Clin Orthop Relat Res. 2004;427:171\u20138.","journal-title":"Clin Orthop Relat Res"},{"key":"338_CR16","doi-asserted-by":"publisher","DOI":"10.1016\/j.clinbiomech.2024.106335","volume":"120","author":"D Yang","year":"2024","unstructured":"Yang D, Zhao Y, Wang Z, Shi H, Huang Y, Zhou Y. Soft tissue elasticity in total knee arthroplasty: an in vivo quantitative analysis. 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Knee. 2012;19(2):130\u20134.","journal-title":"Knee"},{"issue":"4","key":"338_CR27","doi-asserted-by":"publisher","first-page":"237","DOI":"10.1007\/BF01567970","volume":"4","author":"HP Lobenhoffer","year":"1996","unstructured":"Lobenhoffer HP, Bosch U, Gerich TG. Role of posterior capsulotomy for the treatment of extension deficits of the knee. 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Ethics approval was obtained from the Institutional Review Board (IRB) of the hospital (K-2003008\u201300). Informed consent was obtained for all contacted participants.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and and consent to participate"}},{"value":"This study involves fully anonymized data, and no personally identifiable information (including names, images, or any individual details) is included in the manuscript. Therefore, consent for publication is not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to publication"}},{"value":"Yixin Zhou is the Editorial Board of\n                      Arthroplasty\n                      \u00a0and other authors declare that they have no competing interests. All authors were not involved in the journal\u2019s review or decisions related to this manuscript.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing Interest"}}],"article-number":"53"}}