title: Distal semimembranosus muscle-tendon-unit review: morphology, accurate terminology, and clinical relevance.
abstract: BACKGROUND
  Our knowledge of the stability of the posteromedial knee is evolving. The distal semimembranosus is an important posteromedial stabilizer of the knee. Current anatomical texts and atlases do not accurately detail the distal insertion. Journal literature commonly mentions multiple distal insertions, one of which contributes to the oblique popliteal ligament. The purpose of this study was to review the literature, current morphology, terminology and clinical relevance of the distal semimembranosus muscle-tendon-unit (SMTU), and suggest alternative nomenclature. :
  
  
  METHODS
  Literature search was conducted on anatomical and clinical texts, atlases, journals and websites to analyze the distal morphology of the semimembranosus muscle. Deep dissections were performed on 31 embalmed cadavers, 56 knees in total (27Rt and 29L), identifying the distal semimembranosus tendon morphology. : :
  
  
  RESULTS
  Literature search revealed significantly inconsistent morphology of the distal semimembranosus muscle-tendon-unit. Cadaver dissection revealed a consistent trifurcation with three dominant expansions. Cadaver dissection also revealed an oblique popliteal tendon/expansion, indigenous to SMTU, not a ligament. :
  
  
  CONCLUSIONS
  This study provides evidence of a consistent morphology and suggests a more precise nomenclature of the distal SMTU, which includes renaming the oblique popliteal ligament as the oblique popliteal tendon/expansion.
authors.affiliation: Western University of Health Sciences, Northwest Oregon Health & Sciences University, Lebanon, OR, USA. bbenninger@westernu.edu
authors.forename: Brion
authors.initials: B
authors.lastname: Benninger
authors.forename: Taylor
authors.initials: T
authors.lastname: Delamarter
mesh_terms: D000715:Anatomy / Q000379:methods* / Q000592:standards; D006801:Humans; D007718:Knee Injuries / Q000473:pathology*; D007719:Knee Joint / Q000033:anatomy & histology*; D008022:Ligaments / Q000033:anatomy & histology; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D013710:Tendons / Q000033:anatomy & histology; D009626:Terminology as Topic