Development and In Situ Application of an Adjustable Aiming Device to Guide Extra‐ to Intraarticular Tibial Tunnel Drilling for the Insertion of the Cranial Cruciate Ligament in Dogs

Abstract

To develop and test an arthroscopic aiming device for extra- to intraarticular tibial tunnel drilling emerging at the center of the tibial insertion (CenterTib) of the cranial cruciate ligament (CCL) in medium to large breed dogs. Descriptive experimental study. Fifty-two cadaveric hind limbs of dogs >or=20 kg BW. The mediolateral position and craniocaudal position (ccPos) of CenterTib in relation to the caudomedial meniscotibial ligament were measured on photographs of 46 dissected tibial plateaus. The proximal tibial depth (TibDepth) was determined on lateral radiographs and its correlation with ccPos was assessed using linear regression analysis. Extra- to intraarticular arthroscopic tibial tunnel drilling was performed in 6 independent cadaveric stifles. A C-guide with an adjustable craniocaudal offset was constructed and adjusted according to ccPos estimated based on TibDepth. The position of the resulting bone tunnels was compared with the position of the CenterTib. Pearson's correlation between TibDepth and ccPos was strong (R=0.86; P<.001). ccPos (y) as a function of TibDepth (x) can be expressed as y=-4.8+0.3x. Arthroscopic tunnel drilling resulted in a median deviation of the drill tunnels around the CenterTib of 1 mm. The regression equation and aiming device permit localization and targeting of CenterTib during extra- to intraarticular tibial bone tunnel drilling in vitro. The proposed technique may reduce tibial tunnel misplacement when performing intraarticular CCL repair using a tibial bone tunnel.