navicular syndrome is a chronic degenerative condition of navicular bursa and navicular bone that primarily involves damage to the surface of the bone and the overlying DDFT.
I haven't seen the full text of these, but are they of any interest?
Sherlock, C., Mair, T., & Blunden, T. (2008). Deep erosions of the palmar aspect of the navicular bone diagnosed by standing magnetic resonance imaging. Equine veterinary journal, 40(7), 684-692.
Smith, M. R. W., & Wright, I. M. (2012). Endoscopic evaluation of the navicular bursa: observations, treatment and outcome in 92 cases with identified pathology. Equine veterinary journal, 44(3), 339-345.
Parkes, R., Newton, R., & Dyson, S. (2015). Is there an association between clinical features, response to diagnostic analgesia and radiological findings in horses with a magnetic resonance imaging diagnosis of navicular disease or other injuries of the podotrochlear apparatus?. The Veterinary Journal, 204(1), 40-46.