Ex vivo study of minimally invasive procedures for cartilage removal from the metacarpophalangeal or metatarsophalangeal joint and for fetlock tension band application.

Abstract

To describe reliable minimally invasive procedures for (1) removing cartilage by joint distraction and articular drilling for equine metacarpophalangeal (MCP)/metatarsophalangeal (MTP) arthrodesis; (2) applying a palmar/plantar tension band without MCP/MTP joint luxation. Experimental study. Cadaveric equine limbs (n = 12). All limbs were used to evaluate the drilling technique. First the MCP/MTP joint was distracted with a 5.5-mm cortical screw. Then, through four stab incisions, articular cartilage was removed with a 4.5-mm drill. Six randomly chosen limbs were then tested for minimally invasive tension band application with a specially designed cannula. Accurate positioning of the tension band was assessed radiographically. All MCP/MTP joints were disarticulated, and the areas of removed cartilage were visually assessed and measured by using planimetry. The mean percentage of removed cartilage was 66.8% ± 7.6% for the metacarpus/metatarsus surface, 67.9% ± 8.6% for the proximal phalanx surface, and 59.5% ± 1% for the two sesamoid bones. The tension band could be accurately placed through four stab incisions with the cannula. This minimally invasive technique for cartilage removal was efficient and should be favorable for joint fusion in some clinical situations. The minimally invasive tension band application through stab incisions was feasible and repeatable. These procedures should allow total minimally invasive MCP/MTP arthrodesis and be used in selected clinical cases.