Resident in Equine Surgery University of Queensland Karrabin, Queensland, Australia
Access to the articular surfaces of the distal interphalangeal (DIP) joint and cartilage removal may be inadequate for arthrodesis when using previously described arthroscopic approaches. Using distodorsally located arthroscopic portals and transection of the DIP joint collateral ligaments greater than 80% of DIP joint articular cartilage would be removed with this technique. Twelve cadaver limbs were used. Routine palmar/plantar arthroscopic portals were made and the medial and lateral DIP joint collateral ligaments were transected. Dorsal arthroscopic portals were made 10mm proximal to the coronary band. Cartilage was removed using various sized curettes and motorized burrs. The DIP joints were disarticulated and the areas of cartilage removed were visually assessed and measured using planimetry. The percentage of cartilage removed was calculated. The overall median [IQR] percentage (%) of cartilage removed from the third phalanx was 92.07% [88.74-93.00], 97.26% (95.68-98.37) for the dorsal surface of the navicular bone, 84.03% (78.86-89.93) for the distal border of the navicular bone and 93.15% (88.59-94.58) for the distal condyles of the second phalanx. This minimally invasive technique for cartilage removal was effective and should be considered when performing arthrodesis of the DIP joint. Cartilage was removed from cadaver limbs with no radiographic evidence of osteoarthritis. Greater percentage of articular cartilage removed should result in more rapid osseous union following arthrodesis.
