METHOD FOR INDIVIDUAL ENDOPROSTHESIS OF METACARPOPHALANGEAL JOINT Russian patent published in 2024 - IPC A61B17/56 A61F2/42 

FIELD: medicine.

SUBSTANCE: invention relates to traumatology and orthopedics, and can be used for individual endoprosthesis of metacarpophalangeal joint of hand. Computed tomography—CT of metacarpophalangeal joints (MPJ) is performed. An image of the MPJ of a healthy hand is used to produce an image of how the MPJ of the injured finger should look. Healthy and injured joints are printed on 3D printer. On the produced models, using a drill through the articular surfaces, 1 mm K-wires are inserted into the metacarpal bone and the main phalanx. Medullary canals are drilled out along the inserted wires with cannulated drills 2 mm for the main phalanx and 3.5 mm for the metacarpal bone. Articular surface is treated. Model shaft is spilled with boiling wax with subsequent cooling, and the model shaft is re-drilled, thus creating a wax tunnel. Treated models are filled with silicone of class A, which is modeled according to the shape of the articular surface of the model of a healthy joint. Silicone prototypes of the prostheses are scanned with an intraoral scanner and digital 3D model of the prosthesis is obtained. Virtual models of implants are processed in EXOCAD programs and transferred to a milling machine. Prepared endoprostheses and bone models are sterilized in an autoclave. Arched incision is made along the rear of the metacarpophalangeal joint. Common extensor tendon is separated and moved aside. Joint capsulotomy is performed. Articular surfaces are visualized. 1 mm K-wire is inserted through the articular surface into the metacarpal bone to the base. Wire is placed in the center of the channel; the channel is drilled out along the guide wire. Then, using a WS physiodispenser, cutters from a Lindemann set are used to treat a head of a metacarpal bone in accordance with 3D model without damaging the attachment points of the collateral ligaments of the joint. Through the articular surface in the distal direction, a K-wire is inserted into the main phalanx intramedullary to the head of the phalanx, X-ray control is performed in frontal and lateral projections. Wire is placed in the center of the canal, the canal is drilled with a cannulated drill on the guide wire, selecting the drilling depth depending on the diameter and length of the prosthesis leg. Using a WS physiodispenser, the articular surface of the main phalanx is treated with cutters from the Lindemann set in accordance with 3D model. After the articular surfaces are prepared, the endoprosthesis components are installed, starting from the main phalanx component, by impaction of the endoprosthesis leg into the medullary canal. Metacarpal bone component is installed; X-ray control and movement control are performed.

EFFECT: method provides restoration of MPJ, reduction of pain syndrome, improvement of functional results of surgical treatment, as well as reducing the number of intraoperative and postoperative complications due to restoration of the anatomical integrity of the injured joint.

1 cl, 15 dwg, 1 ex