Evaluation of 4.5 mm and 5.5 mm cannulated drill bits on minimally invasive removal of articular cartilage from the proximal interphalangeal joint in equine cadaver limbs
The objective was to 1) compare 4.5 mm and 5.5 mm cannulated drill bits when removing articular cartilage from the medial and lateral aspects of equine proximal interphalangeal joints on cadaver limbs and 2) prove feasibility of using cannulated drill bits in proximal interphalangeal joints of horses. Two sizes of cannulated drill bits were tested on 32 cadaver limbs (8 forelimbs and 8 hind limbs for each size of drill bit). The 4.5 mm cannulated drill bit (Group 1) was drilled from the medial and lateral aspects of the joint from one cm incision on each side in a three drill tract technique. The 5.5 mm cannulated drill bit (group 2) was performed in the same manner as group 1. The joints were then disarticulated and the soft tissues were removed. Each articular surface was grossly observed and was then digitally photographed to allow planimetry measurements to record the percentage of cartilage removed. Grossly all the tracts appeared to be within the joint and subchondral bone was present in all the tracts. Group 1 (16.07% ± 5.46) had a significantly smaller percentage of cartilage removed compared to group 2 (28.13% ± 5.15). The exact amount of articular cartilage necessary to be removed in a pastern joint arthrodesis is unknown. Clinical evaluations should be performed using these techniques to know if 16% or 28% of cartilage removed is large enough to allow for clinical fusion of the pastern joint
