RU182958U1 - Silicone insert for the trapezium-metacarpal joint - Google Patents

Abstract

The utility model relates to medicine, namely to traumatology and orthopedics, and is a silicone insert for restoring the function of the trapezium-metacarpal joint. Silicone insert for the trapezium-metacarpal joint, having a complex geometric shape, through holes for fixation, characterized in that the shape of the insert resembles a biconcave lens in cross section, and in the longitudinal section - an irregular ellipse; the liner has a width of up to 15 mm, a length of up to 11 mm, a height in the lateral part of up to 6 mm, in the middle part of up to 3 mm, in the medial part of up to 4 mm, while the medial surface of the liner is concave and the lateral convex; four through holes with a diameter of up to 2 mm pass through the insert in the longitudinal plane.

Description

The utility model relates to medicine, namely to traumatology and orthopedics, and is a silicone insert for restoring the function of the trapezium-metacarpal joint. At the articular end of the trapezium bone, destructive processes often develop after acute and chronic injuries and diseases that cause its deformation, which significantly impairs the function of the trapezium-metacarpal joint and the hand as a whole. The restoration of joint function is possible with radical operations such as endoprosthetics, which themselves are very traumatic. Of interest is the search for implants that would restore the function of the joint without resection of the articular ends of the bones that form it.

Known bone autograft for replacing a bone defect of the lunate bone, taken from the iliac crest, having a cortical and spongy part, a cylindrical shape with a diameter of up to 1 cm and a height of 1 cm [1].

The disadvantage of this graft is the lack of fixation points to the lunate bone, possible graft osteolysis in the early postoperative period, its instability and migration.

Known bone allograft taken from the tuberosity of the tibia to replace the scaphoid defect, having the shape of a parallelepiped up to 1.5 cm long, up to 1 cm wide, up to 0.8 cm high [2].

The disadvantage of the transplant is the lack of points of its fixation to the scaphoid, a high risk of rejection and resorption of the allograft.

Known silicone implant to eliminate defects of the auricles, having a complex geometric shape, two through holes located in one plane of the implant with a diameter of up to 2 mm for its fixation [3].

The disadvantage of the implant is the presence of only two points of its fixation, which does not ensure its stability and increases the risk of migration; the implant cannot be used to restore the integrity of the trapezium-metacarpal joint. This implant was taken by us as a prototype.

The technical result of creating a utility model is the restoration of the function of the trapezium-metacarpal joint without resection of its articular ends.

The technical result is achieved in that the shape of the insert resembles a biconcave lens in cross section, and in the longitudinal section an irregular ellipse; the liner has a width of up to 15 mm, a length of up to 11 mm, a height in the lateral part of up to 6 mm., in the middle part of up to 3 mm., in the medial part of up to 4 mm., while the medial surface of the liner is concave and the lateral convex; four through holes with a diameter of up to 2 mm pass through the insert in the longitudinal plane.

The complex geometric shape of the liner and its dimensions are due to the anatomical features of the articulating bones and, in particular, the articular ends of the bones that form the trapezium-metacarpal joint. Due to its elasticity, the silicone insert fits easily on the articular surface of the trapezium bone. Through four through holes, the insert is securely fixed to the trapezium bone with transossal sutures. The material of the liner provides its damping properties during movements and loads. After installing the silicone insert, the anatomical shape of the bone-trapezoid is restored. This prevents the formation of subluxation of the I metacarpal bone and restores the function of the trapezium-metacarpal joint.

The utility model is illustrated by graphic material. Figure 1 and figure 2 shows a silicone insert that has a medial (1), middle (2) and lateral (3) parts, a convex lateral surface (4), a concave medial surface (5), four through holes (6).

Silicone liner is used as follows. Intraoperatively, the insert is placed in the cavity of the trapezium-metacarpal joint so that its concave medial surface faces the lateral surface of the base of the second metacarpal bone and fits snugly to it, its convex lateral surface is in place of the lateral tubercle of the trapezium bone, replacing the formed defect of the trapezium, restoring the most "saddle" shape of the trapezoid bone.

The insert is fixed to the trapezium bone through four through holes with transossal sutures. Combine the surface of the liner with the head of the metacarpal bone, checking the stability of the joint. Suture the wound.

The use of the silicone insert of the trapezium-metacarpal joint is illustrated by a clinical example.

Patient Z., 63 years old, was admitted to the department of traumatology and orthopedics of the NKZ DKB at st. Samara 03/20/2017 with a diagnosis of Deforming arthrosis of the trapezio-metacarpal joint of the right hand with a subluxation of the I metacarpal bone. NSF 2 degree. Persistent pain. The operation was performed - installation of the developed silicone insert in the cavity of the trapezium-metacarpal joint with its transossal fixation. Subluxation of the I metacarpal bone and deformation of the trapezius-metacarpal joint were eliminated. There were no intraoperative complications during insert insertion. In the postoperative period - implant fixation was stable, insolvency, no migration was observed. After a period of rehabilitation, the patient fully restored the function of the trapezium-metacarpal joint, she returned to the usual loads on the hand.

The silicone insert can be used in trauma and orthopedic hospitals to restore the function of the trapezium-metacarpal joint when performing reconstructive operations on the hand.

Information sources

1. Bochud RS, Buchler U: Kienbock disease, early stage 3-Height reconstruction and core revascularization of the lunate, J Hand Surj 19: 466-478, 1994;

2. Arora R, Gschwentner M, Krappinger D, et al: Fixation of nondisplaced scaphoid fractures: making treatment cost effective; prospective controlled trial, Arch Orthop Trauma Surg 127: 34-39, 2007;

3. http://facesurgery.pro/news/lechenie-defectov-ushnoi-rakovinyi.html, 2015.

Claims (1)

Silicone insert for the trapezium-metacarpal joint, having a complex geometric shape, through holes for fixation, characterized in that the shape of the insert resembles a biconcave lens in cross section, and in the longitudinal section - an irregular ellipse; the liner has a width of up to 15 mm, a length of up to 11 mm, a height in the lateral part of up to 6 mm, in the middle part of up to 3 mm, in the medial part of up to 4 mm, while the medial surface of the liner is concave and the lateral convex; four through holes with a diameter of up to 2 mm pass through the insert in the longitudinal plane.

Images