This review explores the technological advancements in, engineering considerations regarding, and quality standards of veterinary patellar groove replacement implants. Veterinary-specific regulations for these implants are currently lacking. Therefore, human knee implant benchmarks are used as references. These benchmarks guide evaluation of the surface quality, material selection, biocompatibility, and mechanical performance of the implant to ensure reliability and longevity. Patellar luxation is a common orthopedic disorder in small animals which leads to patellofemoral joint instability and cartilage degeneration, and is often caused by angular limb deformities that disrupt patellar alignment. In severe cases, patellar groove replacement is necessary to restore function and alleviate pain. The implant materials must provide durability, mechanical strength, and biocompatibility to withstand joint forces while ensuring minimal wear. High-quality surface finishes reduce the friction experienced by these materials, improving their long-term performance. Advances in 3D printing allow the creation of patient-specific implants. These implants offer an enhanced anatomical fit and enhanced functionality, which is especially beneficial in complex cases. However, challenges remain in achieving consistent manufacturing quality and economic feasibility. While custom implants are invaluable for difficult cases, standardized designs are sufficient for routine applications. Combining human implant standards with new manufacturing technologies improves veterinary orthopedic solutions. This integration expands the treatment options for patellar luxation and enhances the quality and accessibility of implants.

Laparotomic attenuation of an intrahepatic portosystemic shunt (IHPSS) is more difficult than an extrahepatic one, and results in a higher risk of complications because the identification of the aberrant vessel in the liver remains often a challenge. Excessive preparation and traction of the parenchyma results in trauma, bleeding, and prolonged surgery, which is what worsens the prognosis. Therefore, based on computed tomographic angiography, we printed 3-dimensional (3D) individual patient liver models, scaled 1:1, and used them for surgery planning and as a guide during intraoperative identification of the shunt in four dogs with IHPSS. The advantages of the 3D technology are simple and precise planning of the surgery, fast intraoperative identification of the shunt, and low invasive dissection of the liver parenchyma. We conclude that 3D technology can potentially raise the recovery rate. To the best of our knowledge, this was the first application of 3D models in the surgery of canine IHPSS.

(1) Background: Anatomically pre-contoured plates usually require only minimal or even no intraoperative contouring. For complex cases, such plates also assist the surgeon as an anatomical template during fracture reduction. In this study, we present our experience of using a 3D printing technology for the treatment of bicondylar humeral fractures in feline cadavers. (2) Methods: Surgeries were performed on 15 pairs of front limbs amputated at the scapula. The limbs were obtained from 15 adult cats without obvious pathology of the skeleton. After flexion of the elbow and subperiosteal elevation of the anconeus muscle, the humeral Y-T fractures were created using a bone chisel and mallet. A custom-made anatomically pre-contoured interlocking plate was used to reduce and stabilise the medial aspect of the humeral condyle to the humeral diaphysis. After reduction of the humeral condyle, a positional locking screw was then inserted from the medial to the lateral side and a straight 2.4/2.7 interlocking bone plate was used to stabilise the lateral part of the condyle to the humeral diaphysis. (3) Results: The length of the humerus ranged from 98.2 to 107.0 mm and did not differ significantly between the left and right bone. The diameter of the isthmus of the humeral condyle ranged from 5.2 to 5.5 mm and did not differ significantly between the left and right bone. In all 30 limbs, bicondylar fracture was accompanied by epicondylar comminution. In 7/30 limbs (4 left, 3 right) the fracture of the humeral shaft was also present. In the left limbs, the postoperative articular surface defect of the humeral condyle was small (2 mm) in 2/15 cases in which the condylar screw was incorrectly inserted. In the right limbs, the postoperative articular surface defect of the humeral condyle was small (<1 mm) in 14/15 cases and moderate (1–2 mm) in 1 case. (4) Conclusions: 3D printing and the technology of metal powder sintering offers a wide range of possibilities for the development of new surgical implants. The anatomically pre-contoured bone plate appears to be a valuable tool in the reduction and stabilisation of Y-T humeral fractures in adult domestic cats weighing 3.0 to 4.5 kg.

The medial approach is a traditional portal during elbow arthroscopy. Some researchers have suggested that the caudo-medial arthroscopic approach allows better visualization of the medial and caudal elbow compartments. Such a portal is created caudally to the medial humeral epicondyle’s caudal aspect in the ulnar nerve’s vicinity. Therefore, we investigated the risk of ulnar nerve injury following the caudo-medial portal placement in 30 canine cadavers. After the telescope was inserted, an incision was made to visualize the nerve, and the distance between the cannula and the nerve was measured. An injury was diagnosed when the telescope at least scratched the nerve. The distance between the arthroscopic cannula and the ulnar nerve ranged from 0 to 8.0 mm (median: 0.5 mm) in 60 joints. Nerve injury occurred in 16/30 dogs (53%; CI 95%: 36%, 70%)—in 11 unilaterally and 5 bilaterally. In addition, in eight dogs, the cannula directly touched the nerve, creating a high risk of trauma. In total, nerve injury or high risk of trauma occurred in 21/30 dogs (70%; CI 95%: 52%, 83%). Ulnar nerve injury during caudo-medial arthroscopic portal creation appears common.

The aim of this study was to compare the degree of visibility of the lateral and medial menisci before and after tibial plateau leveling osteotomy (TPLO) on 3D-printed models created after laser scanning of the right tibia with menisci derived from a fresh cadaver of a 4-year-old adult male golden retriever. The models were produced of white polylactic acid, and the menisci were filled with light-curing red resin. The models showed a similar conformation as the natural specimen harvested from the cadaver, maintaining the same length and width, in addition to reproducing the anatomical structures. From the pre- and post-TPLO radiographs, it was possible to identify the anatomical structures corresponding to the tibial plateau. The preoperative tibial plateau angle was 26.2°, and the postoperative one ranged between 4.0° and 5.3° (4.6 ± 0.4°). In the bird’s-eye photo, the total number of red pixels in the lateral and the medial meniscus was 2,053,995 and 2,140,939, respectively. Before TPLO, only between 14% and 19% of the entire area of the menisci was visible, and the unhidden part of the entire area of the meniscus before TPLO did not differ significantly between the lateral (16.2 ± 1.6%) and the medial (16.4 ± 1.6%) meniscus (p = 0.351). The visible part of the entire meniscus area increased significantly after TPLO both in the lateral and medial menisci (p < 0.001)—mean difference ± SD of 30.3 ± 4.3% (CI 95%: 27.9%, 32.6%) and 36.4 ± 6.4% (CI 95%: 32.9%, 40.0%), respectively. In conclusion, the intraoperative examination and treatment of dog menisci are easier after TPLO.

Atlantoaxial instability (AAI) in toy- and small-breed dogs remains a significant clinical challenge, as the restricted anatomical space and risk of complications complicate the selection of implants. This study aimed to compare three patient-specific Ti-6Al-4V stabilizers for the C1–C2 region: a clinically used ventral C1–C3 plate, a shortened ventral C1–C2 plate, and a dorsal C1–C2 implant. Computed tomography, segmentation, virtual reduction, CAD/CAM design, and finite element analysis were employed to evaluate the linear-static mechanical behavior of each construct under loading ranging from 5 to 25 N, with a focus on displacements, von Mises stresses, and peri-screw bone strains. Additionally, cadaver procedures were performed in nine small-breed dogs using custom drill guides and additively manufactured implants to evaluate procedural feasibility and implantation time. Finite element models demonstrated that all stabilizers operated within material and biological safety limits. The C1–C3 plate exhibited the highest implant stresses, while the C1–C2 plate demonstrated an intermediate response, and the dorsal implant minimized implant stresses, albeit by increasing bone stresses. Cadaver experiments revealed that dorsal fixation required less implantation time than ventral fixation. Collectively, the findings indicate that all evaluated constructs represent safe stabilization options, and the choice of implant should reflect the preferred load-transfer pathway as well as anatomical or surgical constraints that may limit ventral access.