Objective To summarize the surgical treatment methods and progress of inferior patellar pole fractures and provide reference for clinical application. Methods The literature on surgical treatment of inferior patellar pole fractures was extensively reviewed, and the relevant research progress, advantages, and limitations were summarized. Results The inferior pole of the patella is an important part of the knee extension device, which can strengthen the force arm of the quadriceps. Inferior patellar pole fractures are relatively rare and often comminuted, usually requiring surgical treatment. At present, there are various methods to treat inferior patellar pole fractures, including patellectomy of inferior pole, tension-band wiring technique, plate internal fixation, suture anchor fixation, claw-like shape memory alloy, separate vertical wiring technique. Different methods have their own characteristics, advantages, and disadvantages. The single internal fixation method has more complications and is easy to cause fixation failure. Therefore, the trend of combining various internal fixation methods is developing at present. Conclusion When the main fragment of the inferior patellar pole fracture is large and mainly distributed transversely, the combination protocol based on tension-band wiring technique can be regarded as an ideal choice. When the fragments are severely damaged and small, the comprehensive protocol based on suture fixation can result in a better postoperative functional recovery.
Objective To compare the biomechanical differences among the three novel internal fixation modes in treatment of bicondylar four-quadrant fractures of the tibial plateau through finite-element technique, and find an internal fixation modes which was the most consistent with mechanical principles. Methods Based on the CT image data of the tibial plateau of a healthy male volunteer, a bicondylar four-quadrant fracture model of the tibial plateau and three experimental internal fixation modes were established by using finite element analysis software. The anterolateral tibial plateaus of groups A, B, and C were fixed with inverted L-shaped anatomic locking plates. In group A, the anteromedial and posteromedial plateaus were longitudinally fixed with reconstruction plates, and the posterolateral plateau was obliquely fixed with reconstruction plate. In groups B and C, the medial proximal tibia was fixed with T-shaped plate, and the posteromedial plateau was longitudinally fixed with the reconstruction plate or posterolateral plateau was obliquely fixed with the reconstruction plate, respectively. An axial load of 1 200 N was applied to the tibial plateau (a simulation of a 60 kg adult walking with physiological gait), and the maximum displacement of fracture and maximum Von-Mises stress of the tibia, implants, and fracture line were calculated in 3 groups. Results Finite element analysis showed that the stress concentration area of tibia in each group was distributed at the intersection between the fracture line and screw thread, and the stress concentration area of the implant was distributed at the joint of screws and the fracture fragments. When axial load of 1 200 N was applied, the maximum displacement of fracture fragments in the 3 groups was similar, and group A had the largest displacement (0.74 mm) and group B had the smallest displacement (0.65 mm). The maximum Von-Mises stress of implant in group C was the smallest (95.49 MPa), while that in group B was the largest (177.96 MPa). The maximum Von-Mises stress of tibia in group C was the smallest (43.35 MPa), and that in group B was the largest (120.50 MPa). The maximum Von-Mises stress of fracture line in group A was the smallest (42.60 MPa), and that in group B was the largest (120.50 MPa). Conclusion For the bicondylar four-quadrant fracture of the tibial plateau, a T-shaped plate fixed in medial tibial plateau has a stronger supporting effect than the use of two reconstruction plates fixed in the anteromedial and posteromedial plateaus, which should be served as the main plate. The reconstruction plate, which plays an auxiliary role, is easier to achieve anti-glide effect when it is longitudinally fixed in posteromedial plateau than obliquely fixed in posterolateral plateau, which contributes to the establishment of a more stable biomechanical structure.