{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,20]],"date-time":"2025-10-20T00:28:16Z","timestamp":1760920096442,"version":"build-2065373602"},"reference-count":17,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2024,2,28]],"date-time":"2024-02-28T00:00:00Z","timestamp":1709078400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Knee surg. sports traumatol. arthrosc."],"published-print":{"date-parts":[[2024,3]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>Cementless Oxford unicompartmental knee replacement (OUKR) is associated with less pain than cemented OUKR 5 years postoperatively. This may be due to improved fixation at the tibial wall, which transmits tension and reduces stress in the bone below the tibial component. This study compares tibial wall fixation with three different types of fixation: cemented, cementless with hydroxyapatite (HA)\u00a0and cementless with a microporous titanium coat and HA (HA\u2009+\u2009MPC).<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Three consecutive cohorts were identified (<jats:italic>n<\/jats:italic>\u2009=\u2009221 cemented in 2005\u20132007, <jats:italic>n<\/jats:italic>\u2009=\u2009118 HA in 2014\u20132015, <jats:italic>n<\/jats:italic>\u2009=\u2009125 HA\u2009+\u2009MPC in 2016\u20132017). Analysis was performed on anterior\u2013posterior radiographs aligned on the tibial component taken 1\u20132 years postoperatively. Aligned radiographs are needed to see narrow radiolucencies adjacent to the wall. Alignment was assessed with rotation ratio (RR\u2009=\u2009wall width\/internal wall height). Perfect RR is 0.3, and a maximum threshold of 0.5 was used. Quality of fixation to the wall was assessed with fixation ratio (FR\u2009=\u2009bone wall contact height\/total wall height). Notable radiographic features at the tibial wall were also recorded.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>A total of 33\u00a0knees with cement, 37 knees with cementless with HA\u00a0and 57 knees cementless with HA\u2009+\u2009MPC had adequately aligned radiographs. Fixation was significantly better with HA compared with cement (55% vs. 25%, <jats:italic>p<\/jats:italic>\u2009=\u20090.0016). The microporous coat further improved fixation (81% vs. 55%, <jats:italic>p<\/jats:italic>\u2009&lt;\u20090.0001). FR\u2009&gt;\u200980% was achieved in 3% of the cemented implants, 32% of HA\u00a0and 68% of HA\u2009+\u2009MPC. In cementless cohorts, features suggestive of a layer of bone that had delaminated from the wall were seen in 8 (22%) HA and 3 (5%) HA\u2009+\u2009MPC knees.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Radiographic tibial wall fixation in OUKR is poor with cement. It improves with an HA coating and improves further with an intermediary MPC. Improved tibial wall fixation may explain the lower levels of pain observed with cementless rather than cemented fixation described in the literature, but further clinical correlation is needed.<\/jats:p><\/jats:sec><jats:sec><jats:title>Level of Evidence<\/jats:title><jats:p>Level III, retrospective cohort study.<\/jats:p><\/jats:sec>","DOI":"10.1002\/ksa.12092","type":"journal-article","created":{"date-parts":[[2024,2,28]],"date-time":"2024-02-28T06:45:16Z","timestamp":1709102716000},"page":"704-712","source":"Crossref","is-referenced-by-count":1,"title":["Microporous titanium and hydroxyapatite improve fixation of the tibial wall in unicompartmental knee replacement"],"prefix":"10.1002","volume":"32","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7225-1245","authenticated-orcid":false,"given":"Azmi","family":"Rahman","sequence":"first","affiliation":[{"name":"Oxford Orthopaedic Engineering Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Botnar Research Centre University of Oxford Oxford UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabrielle","family":"Omoregie","sequence":"additional","affiliation":[{"name":"Indiana University School of Medicine Indianapolis Indiana USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stephen","family":"Mellon","sequence":"additional","affiliation":[{"name":"Oxford Orthopaedic Engineering Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Botnar Research Centre University of Oxford Oxford UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David W.","family":"Murray","sequence":"additional","affiliation":[{"name":"Oxford Orthopaedic Engineering Centre, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Botnar Research Centre University of Oxford Oxford UK"},{"name":"Nuffield Orthopaedic Centre Oxford University Hospitals NHS Foundation Trust Oxford UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2024,2,28]]},"reference":[{"doi-asserted-by":"publisher","key":"e_1_2_11_2_1","DOI":"10.2106\/00004623-200411000-00028"},{"doi-asserted-by":"publisher","key":"e_1_2_11_3_1","DOI":"10.1007\/s00167-021-06617-5"},{"doi-asserted-by":"publisher","key":"e_1_2_11_4_1","DOI":"10.1302\/0301-620X.91B7.21914"},{"doi-asserted-by":"publisher","key":"e_1_2_11_5_1","DOI":"10.1007\/s40520-013-0101-2"},{"doi-asserted-by":"publisher","key":"e_1_2_11_6_1","DOI":"10.1016\/j.bioactmat.2020.10.006"},{"doi-asserted-by":"publisher","key":"e_1_2_11_7_1","DOI":"10.1302\/0301-620X.97B2.34331"},{"doi-asserted-by":"publisher","key":"e_1_2_11_8_1","DOI":"10.1016\/j.knee.2021.08.015"},{"doi-asserted-by":"publisher","key":"e_1_2_11_9_1","DOI":"10.1002\/jor.1100070415"},{"doi-asserted-by":"publisher","key":"e_1_2_11_10_1","DOI":"10.1016\/0142-9612(91)90010-8"},{"key":"e_1_2_11_11_1","first-page":"29","article-title":"Primary bone\u2010formation in porous hydroxyapatite ceramic\u2014a light and scanning electron\u2010microscopic study","volume":"1","author":"Okumura M","year":"1991","journal-title":"Cells\u00a0Mater"},{"doi-asserted-by":"publisher","key":"e_1_2_11_12_1","DOI":"10.3390\/jcm9051476"},{"doi-asserted-by":"publisher","key":"e_1_2_11_13_1","DOI":"10.1007\/s00167-023-07589-4"},{"doi-asserted-by":"publisher","key":"e_1_2_11_14_1","DOI":"10.1177\/2041303310395074"},{"doi-asserted-by":"publisher","key":"e_1_2_11_15_1","DOI":"10.1016\/j.medengphy.2009.02.004"},{"doi-asserted-by":"publisher","key":"e_1_2_11_16_1","DOI":"10.1016\/j.arth.2013.01.004"},{"doi-asserted-by":"publisher","key":"e_1_2_11_17_1","DOI":"10.1016\/j.arth.2021.05.025"},{"doi-asserted-by":"publisher","key":"e_1_2_11_18_1","DOI":"10.1111\/j.1600-0501.2005.01195.x"}],"container-title":["Knee Surgery, Sports Traumatology, Arthroscopy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/esskajournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ksa.12092","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,19]],"date-time":"2025-10-19T10:33:18Z","timestamp":1760869998000},"score":1,"resource":{"primary":{"URL":"https:\/\/esskajournals.onlinelibrary.wiley.com\/doi\/10.1002\/ksa.12092"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,2,28]]},"references-count":17,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2024,3]]}},"alternative-id":["10.1002\/ksa.12092"],"URL":"https:\/\/doi.org\/10.1002\/ksa.12092","archive":["Portico"],"relation":{},"ISSN":["0942-2056","1433-7347"],"issn-type":[{"type":"print","value":"0942-2056"},{"type":"electronic","value":"1433-7347"}],"subject":[],"published":{"date-parts":[[2024,2,28]]}}}