{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T22:22:33Z","timestamp":1790202153395,"version":"4.1.0"},"reference-count":12,"publisher":"Bentham Science Publishers Ltd.","issue":"1","license":[{"start":{"date-parts":[[2008,4,11]],"date-time":"2008-04-11T00:00:00Z","timestamp":1207872000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/legalcode"}],"content-domain":{"domain":["openorthopaedicsjournal.com","benthamopen.com"],"crossmark-restriction":true},"short-container-title":["TOORTHJ"],"published-print":{"date-parts":[[2008,4,11]]},"abstract":"<jats:p>\n                    Creep and true wear of polyethylene are difficult to evaluate on radiographs of knee arthroplasties and for this reason the true rate of polyethylene wear\n                    <jats:italic>in vivo<\/jats:italic>\n                    after unicompartmental arthroplasty is not well known. This study evaluated the creep and true wear in fifty-five medial retrieved unicompartmental implants that had a flat articular surface at the time of implantation.\n                  <\/jats:p>\n                  <jats:p>All the full polyethylene tibial components had the same design and were retrieved from eleven to 224 months (mean 152 months) after their implantation. The postoperative varus deformity had been measured on weight-bearing radiographs of the whole limb (hip-knee-ankle angle). The retrieved implants were placed in a coordinate measuring machine and the coordinates of a grid of points were obtained. Using this system, a three dimensional scaled image of the implant could be created and was used to calculate the total penetration of the femoral condyle due to true wear and creep.<\/jats:p>\n                  <jats:p>Total linear penetration rates ranged from 0.18 to 2.6 millimeters per year (mean 0.25 millimeters per year). Linear penetration rates due to true wear ranged from 0.08 to 1.4 millimeters per year (mean 0.13\u00a0millimeter per year), and penetration due to creep ranged from 0.07 to 1.9 millimeters per year (mean 0.12 millimeters per year).<\/jats:p>\n                  <jats:p>The linear and volumetric penetration rates of the femoral condyle due to true wear were negatively correlated with the duration of implantation. The linear penetration rate due to creep was higher in the first two years after the implantation compared to the subsequent years. Using multiple linear regression analyses to remove the confounding effects of age, weight, gender and thickness of the implant, we found that an increase of the postoperative varus deformity was due to an increase of creep (p = 0.03) but not with an increase of true wear (p = 0.25). Thinner implants were due to an increase of creep (p = 0.02) but not with an increase of true wear (p = 0.34). Increase in age was in relation with decrease of wear (p = 0.02) and increase of weight with increase in creep (p\u00a0=\u00a00.03).<\/jats:p>\n                  <jats:p>Plastic deformation had a high influence on the penetration rate of the femoral condyle in full polyethylene implants. There is a risk of an increased penetration and a decrease of the remaining thickness of the tibial plateau when the implant is too thin, the knee mal-aligned and the patient heavy - each of these factors increasing the creep deformation. In conclusion, our study suggests that surgeons using the Lotus Mk I unicompartmental knee replacement for medial tibiofemoral arthritis should beware of the overweight patient (&gt;90kg) with a tibial implant of less than 9 mm. There is a risk of increased penetration and decreased thickness of the tibial implant when it is too thin, the knee malaligned, and the patient heavy. All these factors increase creep deformation.<\/jats:p>","DOI":"10.2174\/1874325000802010051","type":"journal-article","created":{"date-parts":[[2008,4,24]],"date-time":"2008-04-24T09:17:05Z","timestamp":1209028625000},"page":"51-56","update-policy":"https:\/\/doi.org\/10.2174\/crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Retrieved Unicompartmental Implants with Full PE Tibial Components: The Effects of Knee Alignment and Polyethylene Thickness on Creep and Wear"],"prefix":"10.2174","volume":"2","author":[{"given":"Ph","family":"Hernigou","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A","family":"Poignard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P","family":"Filippini","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S","family":"Zilber","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"965","reference":[{"key":"refR1","doi-asserted-by":"crossref","first-page":"1041","DOI":"10.2106\/00004623-198668070-00010","volume":"68","author":"Bartel DL","year":"1986","unstructured":"Bartel DL, Bicknell VL, Wright TM. \n                    The effect of conformity, thickness and material on stresses in ultra high molecular weight components for total joint replacement  \n                    J Bone Joint Surg (Am)  \n                    1986; \n                    68\n                    (7 )\n                    : 1041-51.","journal-title":"J Bone Joint Surg (Am)"},{"key":"refR2","doi-asserted-by":"crossref","first-page":"1080","DOI":"10.2106\/00004623-199407000-00020","volume":"76","author":"Ly S","year":"1994","unstructured":"Ly S, Brustein AH. \n                    Ultra high molecular weight polyethylene    \n                    J Bone Joint Surg (Am)  \n                    1994; \n                    76\n                    : 1080-90.","journal-title":"J Bone Joint Surg (Am)"},{"key":"refR3","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1097\/00003086-199402000-00003","volume":"299","author":"Bartley RE","year":"1994","unstructured":"Bartley RE, Stulberg SD, Robb WJ, Sweeney HJ. \n                    Polyethylene wear in unicompartmental knee arthroplasty          \n                     Clin Orthop Rel Res  \n                    1994; \n                    299\n                    : 18-24.","journal-title":"Clin Orthop Rel Res"},{"key":"refR4","doi-asserted-by":"crossref","first-page":"247","DOI":"10.3109\/17453679209154776","volume":"63","author":"Blunn GW","year":"1992","unstructured":"Blunn GW, Joshi AB, Lilley PA, et al. \n                    Polyethylene wear in unicondylar knee prostheses. 106 retrieved Marmor PCA and St Georg tibial components compared    \n                      Acta Orthop Scand  \n                    1992; \n                    63 \n                    (3 )\n                    : 247-55.","journal-title":"Acta Orthop Scand"},{"key":"refR5","first-page":"193","volume":"287","author":"Choon JJL","year":"1993","unstructured":"Choon JJL, Rand JA. \n                    Revision of failed unicompartmental knee arthroplasty       \n                    Clin Orthop  \n                    1993; \n                    287\n                    : 193-201.","journal-title":"Clin Orthop"},{"key":"refR6","doi-asserted-by":"crossref","first-page":"260","DOI":"10.3109\/17453679209154778","volume":"63","author":"Lindstrand A","year":"1992","unstructured":"Lindstrand A, Stenstrom A. \n                    Polyethylene wear of the PCA unicompartmental knee. Prospective 5 (4-8) year study of 120 arthrosis knees \n                     Acta Orthop Scand  \n                    1992; \n                    63 \n                    (3  )\n                    : 260-.","journal-title":"Acta Orthop Scand"},{"key":"refR7","first-page":"60","volume":"299","author":"Feng EL","year":"1994","unstructured":"Feng EL, Stulberg SD, Wixson RL. \n                    Progressive subluxation and polyethylene wear in total knee replacements with flat articular surfaces \n                    Clin Orthop  \n                    1994; \n                    299\n                    : 60-71.","journal-title":"Clin Orthop"},{"key":"refR8","first-page":"5","volume":"46","author":"Harman MK","year":"2000","unstructured":"Harman MK, Banks SA, Pue E, Hugde WA. \n                    Depth and rate of surface deformation or retrieved polyethylene tibial inserts  \n                     Trans Orthop Res Soc  \n                    2000; \n                    46\n                    : 5.","journal-title":"Trans Orthop Res Soc"},{"key":"refR9","first-page":"155","volume":"410","author":"Muratoglu O","year":"2004","unstructured":"Muratoglu O, Perinchief R, Bradgon CR, O'Connor D, Konrad R, Harris N. \n                    Metrology to quantify wear and creep of polyethylene tibial knee inserts \n                    Chir Orthop  \n                    2004; \n                    410\n                    : 155-67.","journal-title":"Chir Orthop"},{"key":"refR10","first-page":"221","volume":"20","author":"Herzog R","year":"1991","unstructured":"Herzog R, Morscher E. \n                    Failures of knee joint prostheses. An analysis of knee prostheses and component revisions, 1980-1987 \n                    Orthopade  \n                    1991; \n                    20\n                    : 221-6.","journal-title":"Orthopade"},{"key":"refR11","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1002\/jbm.820170510","volume":"17","author":"Hood RW","year":"1983","unstructured":"Hood RW, Wright TM, Burstein AH. \n                    Retrieval analysis of total knee prostheses: a method and its application to 48 total condylar prostheses \n                    J Biomed Mater Res  \n                    1983; \n                    17\n                    : 829-42.","journal-title":"J Biomed Mater Res"},{"key":"refR12","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1097\/00003086-199402000-00005","volume":"299","author":"Wasielewski RC","year":"1994","unstructured":"Wasielewski RC, Galante JO, Leighty RM, Natarajan RN, Rosenberg AG. \n                    Wear patterns on retrieved polyethylene tibial inserts and their relasionship to technical considerations during total knee arthroplasty \n                    Clin Orthop  \n                    1994; \n                    299\n                    : 31-43.","journal-title":"Clin Orthop"}],"container-title":["The Open Orthopaedics Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/openorthopaedicsjournal.com\/contents\/volumes\/V2\/TOORTHJ-2-51\/TOORTHJ-2-51.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/openorthopaedicsjournal.com\/contents\/volumes\/V2\/TOORTHJ-2-51\/TOORTHJ-2-51.xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/openorthopaedicsjournal.com\/contents\/volumes\/V2\/TOORTHJ-2-51\/TOORTHJ-2-51.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,24]],"date-time":"2025-10-24T10:21:04Z","timestamp":1761301264000},"score":1,"resource":{"primary":{"URL":"https:\/\/openorthopaedicsjournal.com\/VOLUME\/2\/PAGE\/51\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,4,11]]},"references-count":12,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2008,4,11]]}},"alternative-id":["TOORTHJ-2-51"],"URL":"https:\/\/doi.org\/10.2174\/1874325000802010051","relation":{},"ISSN":["1874-3250"],"issn-type":[{"value":"1874-3250","type":"print"}],"subject":[],"published":{"date-parts":[[2008,4,11]]},"assertion":[{"value":"Peer Reviewed","order":0,"name":"review_status","label":"Review Status","group":{"name":"peer_review_details","label":"Peer Review Details"}},{"value":"Double blind","order":1,"name":"review_process","label":"Review Process","group":{"name":"peer_review_details","label":"Peer Review Details"}},{"value":"Checked with iThenticate","order":0,"name":"screening_status","label":"Screening Status","group":{"name":"plagiarism_screening","label":"Plagiarism Screening"}},{"value":"2008-03-03","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2008-03-18","order":1,"name":"revised","label":"Revised","group":{"name":"publication_history","label":"Publication History"}},{"value":"2008-03-27","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2008-04-11","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}