Comparison of Three Drilling Techniques for Carpometacarpal Joint Arthrodesis in Horses

Abstract

Technique 1 (fanning) and 2 (5.5 mm 3 drill tracts) may be preferable to achieve arthrodesis of the CMC joint. Morbidity and efficacy of these arthrodesis techniques need to be evaluated in vivo.

Long-Term Follow-Up Information of a Three-Tract Arthrodesis Technique for Treatment of Carpometacarpal Osteoarthritis

“…We suspect the horses that did poorly had their arthritis worsened by surgery without it producing the desired eventual bony fusion. In the cadaver research, articular damage was greater to the proximal articular surfaces with the fanning technique, likely from inadvertent pressure on the drill displacing the bit proximally [3]. However, if that error in technique did not occur during treatment of clinical cases [2], the amount of surface area damaged would be considerably greater than with the three-drill-track technique.…”

“…We used a 5.5-mm drill bit in four horses (six limbs), rather than the 4.5-mm drill bit used with the fanning technique [2] because a cadaver study showed the three-drill-tract technique with a 5.5-mm drill bit had a comparable amount of articular cartilage destruction as the fanning technique with a 4.5-mm drill bit and was superior to a 4.5-drill bit with the three-drill-tract technique [3]. We used a larger drill bit size (7.0 mm) in two cases (three limbs) to increase the width and depth of the drill tracts and, hence, surface area available for bony fusion.…”

“…However, variability in the amount of fanning of the drill bit between surgeons, and, hence, variability in the quantity of cartilage removed by each surgeon were listed as potential limitations of the fanning technique. It was felt that a technique that produced a more standardized amount of damage to the articular cartilage and subchondral bone and that was less invasive and quicker would be a benefit [3]. A cadaver Fig.…”

“…Note the extensive proliferative new bone formation extending to the middle carpal joint and the carpometacarpal joint which is clearly not fused (arrows). study was performed to evaluate three CMC arthrodesis techniques [3]; technique 1 used the original fanning technique first described [2] using a 4.5-mm drill bit; and techniques 2 and 3 described a three-drill-tract technique using 5.5-and 4.5-mm drill bits, respectively [3]. This study suggested that techniques 2 and 3 had advantages over technique 1 because they decreased subjectivity in the amount of fanning of the drill bit needed to destroy cartilage and/or subchondral bone and were simpler and easier to perform; and technique 2 produced more cartilage damage than technique 3 [3].…”

“…study was performed to evaluate three CMC arthrodesis techniques [3]; technique 1 used the original fanning technique first described [2] using a 4.5-mm drill bit; and techniques 2 and 3 described a three-drill-tract technique using 5.5-and 4.5-mm drill bits, respectively [3]. This study suggested that techniques 2 and 3 had advantages over technique 1 because they decreased subjectivity in the amount of fanning of the drill bit needed to destroy cartilage and/or subchondral bone and were simpler and easier to perform; and technique 2 produced more cartilage damage than technique 3 [3]. However, when the three-drill-tract technique using a 5.5-mm drill bit was evaluated in research horses that were free of lameness and had radiographically normal carpi, arthrodesis only occurred in two of six CMC joints [4].…”