{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T14:07:39Z","timestamp":1774620459365,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T00:00:00Z","timestamp":1774483200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background\/Objectives: Medial meniscus extrusion (MME) is a quantitative marker of altered meniscal containment and load sharing. Although ultrasonography enables dynamic assessment under functional loading, it remains unclear whether generalized ligamentous hypermobility influences physiologic extrusion behavior in healthy knees. The aim of this study was to quantify load-dependent MME in healthy adults and to determine whether generalized hypermobility is associated with greater physiologic extrusion under progressive loading conditions. Methods: In this prospective observational study, 106 healthy adults aged 18\u201340 years were evaluated between October and December 2025. Generalized joint hypermobility was defined as a Beighton score \u22655. MME was measured by standardized ultrasonography on the dominant limb in three conditions: sitting (unloaded), bipedal stance, and unipedal stance. Patellar tendon shear-wave elastography (SWE) was recorded in kilopascals (kPa). Interobserver reliability was assessed in the first 25 participants using ICC (2,1). Group comparisons, multivariable linear regression for loading-related \u0394-extrusion (Unipedal\u2212Sitting and Bipedal\u2212Sitting), and a linear mixed-effects model for repeated MME measures, including a Position \u00d7 Hypermobility interaction, were performed. Results: Twenty-eight participants (26.4%) were classified as hypermobile. The hypermobile group showed significantly lower patellar tendon SWE than controls (23.8 \u00b1 7.0 vs. 37.6 \u00b1 9.7 kPa, p &lt; 0.001). MME increased stepwise with loading in both groups and remained consistently higher in hypermobile participants across sitting, bipedal, and unipedal conditions (all p &lt; 0.001). Loading-related extrusion was also greater in the hypermobile group for both Bipedal\u2212Sitting (p = 0.037) and Unipedal\u2212Sitting (p = 0.002). In multivariable regression, lower patellar tendon SWE independently predicted greater loading-related extrusion, whereas hypermobility status did not remain an independent predictor. In the mixed model, the Position \u00d7 Hypermobility interaction was significant and was most pronounced during the unipedal stance. Conclusions: In healthy adults, medial meniscus extrusion increases stepwise from unloaded sitting to bipedal and unipedal weight bearing. Participants with generalized hypermobility demonstrated higher physiologic MME values and a more pronounced load-dependent pattern, particularly during unipedal stance. However, in adjusted analyses, lower patellar tendon stiffness on SWE, rather than hypermobility status itself, independently predicted greater loading-related extrusion. These findings support a contextual interpretation of ultrasound-based MME measurements in relation to loading condition and hypermobility phenotype.<\/jats:p>","DOI":"10.3390\/diagnostics16071000","type":"journal-article","created":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T15:10:24Z","timestamp":1774537824000},"page":"1000","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Medial Meniscus Physiologic Extrusion Across Sitting, Bipedal, and Unipedal Stance: The Roles of Generalized Hypermobility and Patellar Tendon Stiffness"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2750-8205","authenticated-orcid":false,"given":"Koray Kaya","family":"Kilic","sequence":"first","affiliation":[{"name":"Department of Radiology, University of Health Sciences, Antalya Education and Research Hospital, 07100 Antalya, T\u00fcrkiye"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nevfel","family":"Kahvecioglu","sequence":"additional","affiliation":[{"name":"Department of Radiology, University of Health Sciences, Antalya Education and Research Hospital, 07100 Antalya, T\u00fcrkiye"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mustafa","family":"Yalcin","sequence":"additional","affiliation":[{"name":"Department of Radiology, University of Health Sciences, Antalya Education and Research Hospital, 07100 Antalya, T\u00fcrkiye"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Serkan","family":"Gurcan","sequence":"additional","affiliation":[{"name":"Private Practice, Gurcan Orthopedics Clinic, Cevizlik, Bak\u0131rk\u00f6y, 34365 Istanbul, T\u00fcrkiye"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7679-9635","authenticated-orcid":false,"given":"Ozkan","family":"Kose","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Traumatology, University of Health Sciences, Antalya Education and Research Hospital, 07100 Antalya, T\u00fcrkiye"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1007\/s12178-022-09768-1","article-title":"Review of Meniscus Anatomy and Biomechanics","volume":"15","author":"Mameri","year":"2022","journal-title":"Curr. Rev. Musculoskelet. Med."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Kim, M.S., In, Y., Kim, H., Jeong, J., and Sohn, S. (2025). Why Hoop Tension Matters: A Biomechanical Perspective on Medial Meniscus Posterior Root Tears-A Narrative Review. Bioengineering, 12.","DOI":"10.3390\/bioengineering12060638"},{"key":"ref_3","first-page":"134","article-title":"Meniscus Root Tears: Current Concepts in Anatomy, Diagnosis, and Treatment Strategies","volume":"2","author":"Toker","year":"2025","journal-title":"Sports Traumatol. Arthrosc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"23259671211043797","DOI":"10.1177\/23259671211043797","article-title":"Meniscal Extrusion: A Narrative Review","volume":"9","author":"Gajjar","year":"2021","journal-title":"Orthop. J. Sports Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1007\/s12178-023-09840-4","article-title":"Meniscal Extrusion: Diagnosis, Etiology, and Treatment Options","volume":"16","author":"Langhans","year":"2023","journal-title":"Curr. Rev. Musculoskelet. Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.ejrad.2018.03.007","article-title":"Medial meniscal extrusion: Detection, evaluation and clinical implications","volume":"102","author":"Swamy","year":"2018","journal-title":"Eur. J. Radiol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Tortorella, F., Boffa, A., Di Martino, A., Andriolo, L., Facchini, G., Di Carlo, M., Miceli, M., Zaffagnini, S., and Filardo, G. (2024). Meniscal Extrusion Correlates with Symptom Severity in Knee Osteoarthritis: An Ultrasound and Magnetic Resonance Imaging Analysis of 100 Patients. J. Clin. Med., 13.","DOI":"10.3390\/jcm13247716"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"584","DOI":"10.2214\/AJR.14.12522","article-title":"Ultrasound assessment of medial meniscal extrusion: A validation study using MRI as reference standard","volume":"204","author":"Lorenzato","year":"2015","journal-title":"AJR Am. J. Roentgenol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3311","DOI":"10.1007\/s00167-018-5341-4","article-title":"No dynamic extrusion of the medial meniscus in ultrasound examination in patients with confirmed root tear lesion","volume":"27","author":"Karpinski","year":"2019","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1007\/s12178-024-09894-y","article-title":"The Role of Ultrasound in the Diagnosis and Treatment of Meniscal Injuries","volume":"17","author":"Johnson","year":"2024","journal-title":"Curr. Rev. Musculoskelet. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1016\/j.jos.2019.09.009","article-title":"Investigation of extrusion of the medial meniscus under full weight-loading conditions using upright weight-loading magnetic resonance imaging and ultrasonography","volume":"25","author":"Shimozaki","year":"2020","journal-title":"J. Orthop. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"23259671251391777","DOI":"10.1177\/23259671251391777","article-title":"Physiologic Medial Meniscal Extrusion with Loading and Flexion Detected by Ultrasound","volume":"13","author":"Kruse","year":"2025","journal-title":"Orthop. J. Sports Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2282","DOI":"10.1007\/s00167-018-4885-7","article-title":"Medial meniscus extrusion increases with age and BMI and is depending on different loading conditions","volume":"26","author":"Achtnich","year":"2018","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1007\/s10396-023-01348-1","article-title":"Evaluation of meniscus extrusion during stair ambulation in healthy volunteers using dynamic ultrasonography: A feasibility study","volume":"50","author":"Hashizume","year":"2023","journal-title":"J. Med. Ultrason."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1148\/radiol.12110986","article-title":"Factors associated with meniscal extrusion in knees with or at risk for osteoarthritis: The Multicenter Osteoarthritis study","volume":"264","author":"Crema","year":"2012","journal-title":"Radiology"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e70325","DOI":"10.1002\/jeo2.70325","article-title":"In vivo dynamic intrusion and extrusion of the menisci in varus and valgus load within a healthy population","volume":"12","author":"Bendak","year":"2025","journal-title":"J. Exp. Orthop."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1723","DOI":"10.1002\/jum.16507","article-title":"A Novel Ultrasound Method of Evaluating Dynamic Extrusion of Lateral Meniscus in Healthy Population: Different Patterns of Dynamic Extrusion Revealed Between Lateral and Medial Meniscus","volume":"43","author":"Meng","year":"2024","journal-title":"J. Ultrasound Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1530\/EOR-2024-0128","article-title":"Ultrasound quantification of knee meniscal extrusion: The potential of weight-bearing and dynamic evaluations. A systematic review","volume":"10","author":"Martinese","year":"2025","journal-title":"EFORT Open Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1186\/s43019-024-00236-3","article-title":"Assessment of meniscal extrusion with ultrasonography: A systematic review and meta-analysis","volume":"36","author":"Boksh","year":"2024","journal-title":"Knee Surg. Relat. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.knee.2023.09.010","article-title":"Meniscal extrusion in knees with and without osteoarticular pathology: A systematic review of normative values and cut-offs for diagnostic criteria","volume":"45","author":"Barreira","year":"2023","journal-title":"Knee"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"110100","DOI":"10.1016\/j.gaitpost.2026.110100","article-title":"The single-leg sit-to-stand test is valid and reliable for assessing lower limb performance and asymmetry in international cross-country skiers","volume":"125","author":"Birinci","year":"2026","journal-title":"Gait Posture"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1002\/ajmg.c.31552","article-title":"The 2017 international classification of the Ehlers-Danlos syndromes","volume":"175","author":"Malfait","year":"2017","journal-title":"Am. J. Med. Genet. Part C Semin. Med. Genet."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"e7625","DOI":"10.7717\/peerj.7625","article-title":"Prevalence of generalized joint hypermobility, musculoskeletal injuries, and chronic musculoskeletal pain among American university students","volume":"7","author":"Reuter","year":"2019","journal-title":"PeerJ"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1002\/art.33319","article-title":"Ultrasonographic evaluation of medial radial displacement of the medial meniscus in knee osteoarthritis","volume":"64","author":"Kawaguchi","year":"2012","journal-title":"Arthritis Rheumatol."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Kot, B.C., Zhang, Z.J., Lee, A.W., Leung, V.Y., and Fu, S.N. (2012). Elastic modulus of muscle and tendon with shear wave ultrasound elastography: Variations with different technical settings. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0044348"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Berrigan, W.A., Cipriano, K., Easley, K.A., and Mautner, K. (2025). Quantifying Mechanical Properties of the Patellar and Achilles Tendons Using Ultrasound Shear Wave Elastography: A Pilot Study. Diagnostics, 15.","DOI":"10.3390\/diagnostics15070879"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1002\/pmrj.12450","article-title":"The Difference in Medial Meniscal Extrusion between Non-Weight-Bearing and Weight-Bearing Positions in People with and without Medial Compartment Knee Osteoarthritis","volume":"13","author":"Reisner","year":"2021","journal-title":"PM R"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1002\/pmrj.12183","article-title":"Ultrasound Assessment of Weight-Bearing and Non-Weight-Bearing Meniscal Extrusion: A Reliability Study","volume":"12","author":"Reisner","year":"2020","journal-title":"PM R"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2867","DOI":"10.1002\/jum.15975","article-title":"Medial Meniscal Extrusion Evaluation with Weight-Bearing Ultrasound: Correlation with MR Imaging Findings and Reported Symptoms: Correlation with MR Imaging Findings and Reported Symptoms","volume":"41","author":"Falkowski","year":"2022","journal-title":"J. Ultrasound Med."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1446","DOI":"10.1002\/ksa.12183","article-title":"Meniscal extrusion consensus statement: A collaborative survey within the Meniscus International Network (MenIN) Study Group","volume":"32","author":"Familiari","year":"2024","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/7\/1000\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T13:02:05Z","timestamp":1774616525000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/7\/1000"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,26]]},"references-count":30,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["diagnostics16071000"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16071000","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,26]]}}}