Research Day
ANATOMY OF THE NAVICULOCUNEIFORM JOINT
Document Type
Abstract
Date
2021
Abstract
Introduction: The naviculocuneiform (NC) joint is implicated in numerous pathologies of the foot and ankle. Purpose: To describe the articular surface of the NC joint. We hypothesize that unique anatomic features of the cartilage surface are useful to guide operative planning.
Methods: The articular cartilage from twenty cadaver NC joints was quantified by calibrated digital imaging software.
Results: For the distal navicular articulation, 75.4% of the mean area was cartilage. The shape of the medial and middle facets was triangular (10/20 and 20/20 specimens, respectively). The fibrous component was at the plantar aspect of the facets. The lateral facet was quadrilateral (10/20) with fibrous tissue along the lateral and plantar borders. For the proximal medial, middle, and lateral cuneiform articulations, 69.6%, 75.7%, and 75.8% the mean areas were cartilage, respectively. The medial and middle facets were triangular (14/20 and 18/20, respectively), and the lateral facet oval (18/20). Mean dorsal-plantar height of the navicular facets was 18mm. The medial, middle, and lateral cuneiform facets were 15mm, 17mm, and 15mm, respectively. Mean length from the medial navicular facet to the middle facet was 41.3% the mean total length across all facets.
Conclusion: When preparing the NC joint for arthrodesis, the surgeon should know that the cartilage can extend 19mm dorsal to plantar. This ensures all cartilage is removed and aids to estimate screw length in subchondral bone. Additionally, the central third of the navicular, where most navicular stress fractures occur, lies in the inter-facet ridge between the medial and middle navicular facets.