Patella inferior pole fracture internal fixing device and screw fixing method

Abstract

The invention discloses a patella inferior pole fracture internal fixing device and a screw fixing method, the patella inferior pole fracture internal fixing device comprises an arc-shaped fixing plate, the arc-shaped fixing plate is attached to a patella; effectively wraps and fixes the subpatellar comminuted fracture block and limits the displacement of the subpatellar comminuted fracture block,and meanwhile, tightly contacts the patella body with the subpatellar comminuted fracture block and pressurizes and fixes the patellar body; the locking between the screw and the steel plate can effectively improve the pull-out resistance of the screw, so that the stability of the fracture block and the internal fixation device is further enhanced, and the looseness and failure of internal fixation are reduced; besides, suture tension reduction protection can be achieved, suture tension reduction stress and patellar ligament traction fracture block stress are kept in dynamic balance, fractureblock displacement or internal fixation failure during early knee bending movement is effectively avoided, meanwhile, damage interference to patellar tendons can be relieved, the tension band principle is considered, the mechanical principle is better met. And a more effective internal fixation choice is provided for treating patella inferior pole fracture, especially comminuted patella inferiorpole fracture.

Description

technical field [0001] The invention relates to the technical field of medical devices, in particular to an internal fixation device and screw fixation method for fractures of the lower pole of the patella. Background technique [0002] The inferior pole of the patella refers to the part of the lower 1 / 4 of the patella that is not covered by articular cartilage, about 1.5 cm long, and does not participate in the formation of the patellofemoral joint. The lower pole of the patella is contained in the patellar ligament (patella tendon) and the infrapatellar fat pad, connects the patellar tendon, and transmits the force of the quadriceps muscle to the tibial tuberosity, thereby completing knee extension. There is very cancellous bone under the patella, and most of the fractures are comminuted fractures. In mild cases, there may be several large fracture fragments. In severe cases, the fracture fragments are small and numerous, but they are still gathered together through the at...

AI Technical Summary

Problems solved by technology

In addition, the patellar tendon insertion point is extremely inferior to the patella, and too many broken bone fragments are removed, resulting in the loss of too many attachment points of the patellar tendon, resulting in poor tendon-bone union, and early postoperative activities are prone to separation of the patellar tendon and patella

[0005] 2. The comminuted fracture of the lower pole of the patella has many fragments and small fracture fragments. The patellar claw and the net plate often cannot achieve effective, reliable, and strong internal fixation. If rehabilitation exercises are performed too early, internal fixation may loosen, shift, and Re-displacement of the fracture fragments requires reoperation in severe cases; if the knee joint is immobilized for a long time before functional exercise, knee joint stiffness and lower extremity venous thrombosis are prone to occur, seriously affecting the patient's postoperative rehabilitation function exercise

[0006] 3. After the comminuted fracture of the lower pole of the patella, the stability of the attachment of the patellar tendon is poor, Kirschner wires and screws cannot be effectively reset and fixed, and simple wire or cable cerclage fixation cannot limit the separation and displacement of the fracture fragment during knee flexion. Tension reduction protection across the patella and patellar tendon or tibial tubercle can help early functional exercise, but the damage of the steel wire or cable interferes significantly with the patellar tendon

[0007] 4. During the flexion and extension of the knee joint, the long axis of the patella and the long axis of the quadriceps muscle change dynamically. When the knee joint is flexed, the shear force on the lower pole of the patella increases, which easily leads to loosening or breaking of the internal fixation.

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