{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T09:48:27Z","timestamp":1782380907562,"version":"3.54.5"},"reference-count":13,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T00:00:00Z","timestamp":1782345600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JPM"],"abstract":"<jats:p>Background\/Objectives: Patellofemoral joint (PFJ) replacement is a bone-preserving option for isolated patellofemoral osteoarthritis; however, reported survivorship and failure patterns remain variable. This study evaluated implant survivorship, functional outcomes, reoperations, and failure mechanisms following PFJ replacement using standard second-generation implant systems, with or without patellar resurfacing. Methods: We retrospectively reviewed a consecutive cohort of 39 patients (48 knees) who underwent PFJ replacement for isolated patellofemoral osteoarthritis between 2011 and 2021. Median age at surgery was 59 years, and median body mass index (BMI) was 31 kg\/m2. Median follow-up for clinical and revision surveillance was 9 years (IQR 8\u201310). Functional outcomes were assessed using the Oxford Knee Score (OKS) and SF-12 Physical and Mental Component Scores (PCS and MCS). Implant survivorship was analyzed using Kaplan\u2013Meier methodology, with conversion to total knee arthroplasty (TKA) as the endpoint. Statistical analyses were primarily descriptive and exploratory because only five TKA revisions occurred. Results: Median OKS improved from 19 (IQR 16\u201324) preoperatively to 36 (IQR 24\u201342) at the latest follow-up, with a median paired improvement of 17 points. SF-12 PCS improved from 25 to 47, and SF-12 MCS from 36 to 55. Eight knees (16.7%) underwent non-revision reoperation, and five knees (10.4%) underwent conversion to TKA. All TKA revisions were performed for the progression of tibiofemoral osteoarthritis. Kaplan\u2013Meier survivorship free from TKA revision was 89.6% at 9 years (95% CI 76.8\u201395.5). No clear difference in TKA-free survivorship was detected between resurfaced and non-resurfaced knees. Conclusions: PFJ replacement demonstrated substantial functional improvement and mid- to long-term survivorship comparable to published registry ranges in a selected cohort with isolated patellofemoral osteoarthritis. TKA revision was uncommon and was attributable to the progression of tibiofemoral osteoarthritis. Because of the retrospective design, small cohort size, bilateral cases, and limited number of revision events, subgroup and risk-factor analyses should be interpreted as exploratory.<\/jats:p>","DOI":"10.3390\/jpm16070345","type":"journal-article","created":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T08:14:12Z","timestamp":1782375252000},"page":"345","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Patellofemoral Joint Replacement for Isolated Patellofemoral Osteoarthritis: Mid- to Long-Term Survivorship and Functional Outcomes"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7830-2207","authenticated-orcid":false,"given":"Fernando","family":"Diaz Dilernia","sequence":"first","affiliation":[{"name":"Division of Orthopaedic Surgery, Department of Surgery, Queen\u2019s University, Kingston, ON K7L 3N6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-1463-4014","authenticated-orcid":false,"given":"Mutaz","family":"Tageldein","sequence":"additional","affiliation":[{"name":"Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9414-1888","authenticated-orcid":false,"given":"Emad","family":"Anam","sequence":"additional","affiliation":[{"name":"Orthopedic Department, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aaron","family":"Campbell","sequence":"additional","affiliation":[{"name":"Division of Orthopaedic Surgery, Department of Surgery, Queen\u2019s University, Kingston, ON K7L 3N6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3907-1696","authenticated-orcid":false,"given":"Gavin","family":"Wood","sequence":"additional","affiliation":[{"name":"Division of Orthopaedics, Department of Surgery, McMaster University, Hamilton, ON L8S 4L8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1697","DOI":"10.1016\/j.joca.2016.05.011","article-title":"The prevalence of patellofemoral osteoarthritis: A systematic review and meta-analysis","volume":"24","author":"Kobayashi","year":"2016","journal-title":"Osteoarthr. Cartil."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"822","DOI":"10.1016\/j.jisako.2024.01.003","article-title":"Patello-femoral arthroplasty- indications and contraindications","volume":"9","author":"Batailler","year":"2024","journal-title":"J. ISAKOS"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"796","DOI":"10.1016\/j.jisako.2023.11.005","article-title":"Outcomes of isolated patellofemoral arthroplasty","volume":"9","author":"Cardenas","year":"2024","journal-title":"J. ISAKOS"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"671","DOI":"10.2340\/17453674.2025.44593","article-title":"Patellofemoral arthroplasty-patient demographics and revision causes compared with total and medial unicompartmental knee arthroplasty: Long-term follow-up data from the Norwegian Arthroplasty Register","volume":"96","author":"Omenas","year":"2025","journal-title":"Acta Orthop."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1302\/0301-620X.107B5.BJJ-2024-1273.R2","article-title":"Outcomes of patellofemoral joint arthroplasty compared with total knee arthroplasty for osteoarthritis: A population-based cohort study using data from the National Joint Registry and Hospital Episode Statistics for England","volume":"107-B","author":"Bottle","year":"2025","journal-title":"Bone Jt. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1186\/s13018-021-02509-z","article-title":"The short-term effectiveness and safety of second-generation patellofemoral arthroplasty and total knee arthroplasty on isolated patellofemoral osteoarthritis: A systematic review and meta-analysis","volume":"16","author":"Li","year":"2021","journal-title":"J. Orthop. Surg. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1186\/s13018-021-02414-5","article-title":"Patellofemoral arthroplasty versus total knee arthroplasty for isolated patellofemoral osteoarthritis: A systematic review and meta-analysis","volume":"16","author":"Peng","year":"2021","journal-title":"J. Orthop. Surg. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.knee.2022.12.016","article-title":"Complications and costs of patellofemoral arthroplasty versus total knee arthroplasty","volume":"41","author":"Serino","year":"2023","journal-title":"Knee"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1965","DOI":"10.1111\/os.70063","article-title":"The Perioperative Resource Use and Effectiveness of Patellofemoral Arthroplasty Versus Total Knee Arthroplasty: A Meta-Analysis","volume":"17","author":"Wu","year":"2025","journal-title":"Orthop. Surg."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1222","DOI":"10.1097\/CORR.0000000000001268","article-title":"Short-term Revision Risk of Patellofemoral Arthroplasty Is High: An Analysis from Eight Large Arthroplasty Registries","volume":"478","author":"Lewis","year":"2020","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1186\/s13018-025-05592-8","article-title":"Outcomes of patellofemoral joint arthroplasty: A systematic review of revision timelines and complication rates","volume":"20","author":"Chughtai","year":"2025","journal-title":"J. Orthop. Surg. Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1933","DOI":"10.1007\/s00167-013-2776-5","article-title":"The minimal clinically important difference in the Oxford knee score and Short Form 12 score after total knee arthroplasty","volume":"22","author":"Clement","year":"2014","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2055","DOI":"10.1007\/s00264-024-06224-2","article-title":"Robotic-assisted patellofemoral arthroplasty provides excellent implant survivorship and high patient satisfaction at mid-term follow-up","volume":"48","author":"Pacchiarotti","year":"2024","journal-title":"Int. Orthop."}],"container-title":["Journal of Personalized Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4426\/16\/7\/345\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T09:30:23Z","timestamp":1782379823000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4426\/16\/7\/345"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,25]]},"references-count":13,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["jpm16070345"],"URL":"https:\/\/doi.org\/10.3390\/jpm16070345","relation":{},"ISSN":["2075-4426"],"issn-type":[{"value":"2075-4426","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,25]]}}}