title: Arterial anatomy of the tibialis posterior tendon.
abstract: BACKGROUND
  Tibialis posterior tendon dysfunction is a common disorder leading to pain, deformity, and disability, although its pathogenesis is unclear. A vascular etiology has been proposed, but there is controversy regarding the existence of a hypovascular region that may render the tendon vulnerable. The purpose of this study was to provide a description of the arterial anatomy supplying the tibialis posterior tendon.
  
  
  METHODS
  Sixty adult cadaveric lower extremities were obtained from a university-affiliated body donation program. Thirty specimens obtained within 72 hours of death were used for microscopic analysis. Thirty specimens were previously frozen and used for macroscopic analysis. The tibialis anterior, tibialis posterior, and peroneal arteries were injected with India Ink and Ward's Blue Latex. The specimens used for macroscopic analysis were debrided with sodium hypochlorite to expose the extratendinous anatomy. For the microscopic analysis, the tendon was cleared using a modified Spälteholz technique to expose the intratendinous vascular anatomy.
  
  
  RESULTS
  Macroscopically, an average of 2.5 ± 0.7 vessels entered the tendon proximal to the navicular insertion. In all, 28/30 (93.3%) specimens had a vessel entering 4.1 ± 0.6 cm proximal to the medial malleolus and 24/30 (80.0%) specimens had a vessel entering 1.7 ± 0.9 cm distal to the medial malleolus. Microscopically, an average of 1.9 ± 0.3 vessels entered each tendon proximal to the navicular insertion. In total, 27/30 (90%) specimens had a vessel entering the tendon 4.8 ± 0.8 cm proximal to the medial malleolus and 30/30 (100%) specimens had a vessel entering the tendon 1.9 ± 0.8 cm distal to the medial malleolus. In all specimens, a hypovascular region was observed, starting 2.2 ± 0.8 cm proximal to the medial malleolus and ending 0.6 ± 0.6 cm proximal to the medial malleolus with an average length of 1.5 ± 1.0 cm. The insertion of the tendon was well vascularized both on microscopic and macroscopic specimens.
  
  
  CONCLUSIONS
  The tibialis posterior tendon was supplied by 2 vessels entering the tendon approximately 4.5 cm proximal and 2.0 cm distal to the medial malleolus. A retromalleolar hypovascular region was observed.
  
  
  CONCLUSIONS
  Improved understanding of the vascularity of the tibialis posterior tendon may be helpful in clinical practice and potentially provides a basis for further evaluation of the causative factors of tibialis posterior tendinopathy.
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Mary Claire
authors.initials: MC
authors.lastname: Manske
authors.affiliation: Andrews Sports Medicine and Orthopaedic Center, Birmingham, AL, USA.
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: McKeon
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Johnson
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: McCormick
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO, USA kleins@wustl.edu.
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Klein
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000033:anatomy & histology / Q000098:blood supply*; D002102:Cadaver; D004210:Dissection; D006801:Humans; D035002:Lower Extremity; D012680:Sensitivity and Specificity; D013710:Tendons / Q000033:anatomy & histology* / Q000098:blood supply*; D013977:Tibia / Q000098:blood supply
keywords: adult acquired flat foot deformity; pes planovalgus; tibialis posterior tendon; tibialis posterior tendon dysfunction; vascular anatomy