Kershaw Joshua T, Oxley Bill, Allen Matthew J
Department of Veterinary Medicine, Surgical Discovery Centre, University of Cambridge, Cambridge, United Kingdom.
Vet3D, Kendall, United Kingdom.
Vet Comp Orthop Traumatol. 2025 Sep;38(5):214-220. doi: 10.1055/a-2510-3720. Epub 2025 Feb 11.
The goal of this study was to compare the accuracy and safety of a transcondylar screw (TCS) placed using a 3D-printed patient-specific guide (PSG) or a generic aiming device (AD). We hypothesized that PSG is more accurate (i.e., positioning and orientation closer to the optimal trajectory) and safer (reduced incidence of joint violation) than the AD.A total of seven pairs of forelimbs were allocated to PSG and AD groups. After CT scanning, the optimal TCS orientation was planned in silico by a surgical specialist, and guides were printed. Using the PSG or AD, a 2.5-mm drill hole was drilled from medial to lateral across the humeral condyle. The positioning of the "planned" and "achieved" drill holes was defined on postoperative CT. The accuracy of TCS positioning and the risk of joint penetration were then calculated for the two groups.Positioning of the entry and exit holes was significantly more accurate in the PSG group. Differences in screw angulation were not significantly different between groups. Despite the presence of an outlier (caused by incomplete seating of the PSG against the bone), 7 out of 7 screws positioned with PSG were "safe," while 3 out of 7 from the AD group would have violated the joint.Our data confirm the technical superiority of PSG over the AD for placement of a TCS in the humeral condyle.
本研究的目的是比较使用3D打印的患者特异性导板（PSG）或通用瞄准装置（AD）置入髁间螺钉（TCS）的准确性和安全性。我们假设PSG比AD更准确（即定位和方向更接近最佳轨迹）且更安全（关节侵犯发生率降低）。总共七对前肢被分配到PSG组和AD组。CT扫描后，由外科专家在计算机上规划TCS的最佳方向，并打印导板。使用PSG或AD，从内侧向外侧穿过肱骨髁钻一个2.5毫米的钻孔。术后CT确定“计划”和“实际”钻孔的位置。然后计算两组TCS定位的准确性和关节穿透的风险。PSG组的进针点和出针点定位明显更准确。两组之间螺钉角度的差异无显著差异。尽管存在一个异常值（由PSG与骨不完全贴合引起），但使用PSG定位的7枚螺钉中有7枚“安全”，而AD组的7枚螺钉中有3枚会侵犯关节。我们的数据证实了在肱骨髁置入TCS时，PSG相对于AD的技术优势。
