RU2848266C1 - Device - bone drilling depth limiter - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to devices used in surgical traumatology and orthopaedics. The bone drilling depth limiter consists of a 20-millimetre bolt from the Ilizarov apparatus set, two 18-millimetre washers mounted on it, and a wing nut. The threaded part of the bolt on one side is bevelled along its entire length from the end surface of the bolt to its head to a uniformly increasing depth from 1/3 to 1/2 of the bolt diameter. One washer is straight, and the other is bent at an angle of 15 degrees and faces the straight washer with its concave surface.

EFFECT: increased effectiveness of treatment for orthopaedic and trauma patients requiring surgical intervention with the formation of intraosseous channels by drilling through the bone.

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Description

The invention relates to medical equipment, namely to devices used in traumatology and orthopedics.

Bone drilling is widely used in surgical traumatology and orthopedics, most often during osteosynthesis of bone fragments. However, the denser the bone, the higher the risk of uncontrolled drill penetration into soft tissue beyond the bone (usually beyond the second cortical plate during standard bicortical drilling of tubular bones). This can lead to damage to important anatomical structures, leading to iatrogenic neuritis and bleeding.

Analogues

To prevent the risk of an uncontrolled “fall” of the drill deeper than intended, with the risk of damaging soft tissue structures outside the bone, there are several practical techniques, including the following:

- decreasing the pressure along the drill axis of the working drill as the drill moves deeper and closer to the end of drilling the intraosseous canal;

- tension of the surgeon's antagonist muscles, preventing pressure along the axis of the rotating drill - in order to stop in time at the moment of its "falling" into the soft tissue;

- safety counter-holding by an assistant while the drill is in the surgeon’s hands;

- use of a factory-installed drilling depth limiter, which consists of metal rings of various sizes, up to seven or more in quantity, with a transverse threaded stopper that moves inside the ring by turning a key with a hexagonal slot.

Criticism of analogs

Reducing the pressure along the drill axis as the bone is being drilled out, although it reduces the risk of the drill "falling" deeper into the soft tissue behind the bone, does not eliminate it completely, and, secondly, it reduces the drilling efficiency and prolongs the procedure, increasing the duration of the operation.

Tension of the surgeon's antagonist muscles, which restrains the pressure along the axis of the rotating drill, in order to stop in time at the moment the drill "falls" beyond the bone into the soft tissue, also does not exclude this "falling" and prolongs the manipulation.

The counter-holding of a surgeon's drill by an assistant while it is in his hands has the same disadvantages as the above-mentioned techniques.

The use of a factory-installed drilling depth limiter, which consists of metal rings of various sizes with an internal diameter from 5 to 15 millimeters with a transverse threaded stopper that extends inside the ring and is activated by turning a key with a hex key, has the following disadvantages: lack of availability in operating rooms of trauma and orthopedic departments and trauma centers of any level; the need for different sizes (up to seven or more) for drills of different diameters; time-consuming and labor-intensive use with the need for an appropriate key with a hex key; small contact area of the transverse threaded stopper with the drill, which causes excessive load per unit area of the drill for adequate fixation of the device on it with a high probability of deformation of its lateral cutting edge.

Therefore, we chose the “defender” – Buyalsky’s spatula – as a prototype.

Prototype

The Buyalsky spatula, described in the manual “General Principles of Surgical Operations Technology” (Burykh M.P. General Principles of Surgical Operations Technology // Manual for Surgeons. - Rostov n / D.: Phoenix Publishing House, 1999. - 544 p.), was chosen as a prototype device. It is a surgical instrument designed, among other things, for inserting it behind a tubular bone on the other side of the bone being drilled at the expected exit site of the drill tip and, thus, preventing damage to soft tissues.

Criticism of the prototype

Although the prototype device, as a protector, minimizes damage to the soft tissue behind the drilled bone, it also has disadvantages, which include the following:

To insert the prototype device beyond the tubular bone on the opposite side from the drilling initiation point in the closest of the two cortical plates, it is necessary to skeletonize (i.e., separate the periosteum sequentially with a straight and then a curved raspatory) _at least ^half the bone circumference. Increasing the skeletonization zone of bone fragments inevitably reduces their vascularization and, consequently, their regenerative potential and resistance to infection. This, in turn, delays fracture healing and increases the risk of postoperative wound suppuration.

- increasing the depth of the surgical wound and the time it takes to heal;

- increase in the duration of surgical intervention.

The purpose of the invention is to optimize the process of drilling bone during orthopedic and traumatological operations, in particular during osteosynthesis of bone fragments in the treatment of fractures, pseudoarthroses and during corrective osteotomies of bones.

The essence of the invention

A device is proposed - a limiter for the depth of drilling into a bone (Fig. 1, a), characterized in that it consists of a 20-millimeter bolt (pos. 1) from the Ilizarov apparatus set, two 18-millimeter washers (pos. 3 and pos. 4) mounted on it and a wing nut (pos. 2), and wherein the threaded part of the bolt (pos. 1) on one of its sides along its entire length is obliquely ground from the end surface of the bolt (pos. 1) to its head to _{a uniformly increasing depth from 1/3 to 1/2} ^of the bolt diameter, one washer is straight (pos. 3), and the other is bent (pos. 4) at an angle of 15 degrees and its concave surface faces the straight washer (pos. 3). This allows, by turning the wing nut (pos. 2) clockwise, to fix the device (Fig. 1, b) on any section of the drill (pos. 5), clamped and locked between both washers (pos. 3 and pos. 4), and by turning the wing nut (pos. 2) counterclockwise, to unlock the drill (pos. 5) and remove the device from it.

This device is usually assembled on the operating table. It is assembled from the listed components (Fig. 1, a) by placing two washers on the bolt (item 1). The first is straight (item 3), and the second is bent at an angle of 15 degrees (item 4), with the concave side of its bend facing the other washer (item 3). Then, a wing nut (item 2) is screwed onto the bolt, thereby preparing the device for use.

The device is used as follows (Fig. 1, b). Having marked the estimated length of the drill section (pos. 5) required for drilling the bone, which is slightly greater than the bone diameter (for example, the bone diameter is 2.5 cm, and the drill section sufficient for drilling and, at the same time, safe for soft tissues outside the bone is 3.0 cm), the device is installed on it in such a way that it is between both washers (pos. 3 and pos. 4), and this position is fixed by tightening the wing nut (pos. 2) clockwise, thereby clamping the drill (pos. 5) between the washers (pos. 3 and pos. 4) and locking the device on it. The bone is then drilled without fear of "falling" into the soft tissue on the other side, since the device acts as a drilling depth limiter and rests with the edge of both washers (pos. 3 and pos. 4) against the surface of the first cortical plate of the bone when the tip of the drill protrudes beyond the second cortical plate. Other holes are drilled in the same manner, and the device is unlocked and removed from the drill (pos. 5) by turning the wing nut (pos. 2) counterclockwise. Example of device use

As an example of the application of the proposed device, we present the following observation.

Patient B., 59, was admitted to the Republican Center for Traumatology and Orthopedics (RCTO) in Makhachkala on November 29, 2023, with a diagnosis of a slow-healing fracture of the distal third of the left ulna. His medical history included a household injury approximately five months earlier. He received conservative treatment in a plaster cast, but the fracture did not heal.

On November 30, 2023, surgery was performed: extraosseous osteosynthesis of the lower third of the left ulna.

Under conduction anesthesia, a linear skin incision was made along the posterior surface of the lower third of the left forearm. The posterior surface of the ulna fragments was exposed and sparingly skeletonized (to the width of the metal structure used—an angularly stable plate), separating them, removing scar tissue, and restoring the diameter of the medullary canal. A bone fragment, unevenly fused to the distal fragment and disrupting the bone contour, was separated, freed from scar tissue, and inserted into the defect between the incongruent bone fragments. External osteosynthesis of the ulna was performed using a 110-mm angularly stable plate on six 3.5-mm screws (Fig. 2, a, b). During this operation, a pre-assembled device was used - a bone drilling depth limiter, consisting of a 20-mm bolt from the Ilizarov apparatus kit, two 18-mm washers and a wing nut mounted on it, and wherein the threaded part of the bolt on one of its sides along its entire length was obliquely ground from the end surface of the bolt to its head to a uniformly increasing depth from 1/3 to 1/2 of the bolt diameter, and one of the two washers, namely, located between the wing nut and the other washer, was bent at an angle of 15 degrees and its concave surface faced the second washer, which made it possible to fix the device on any section of the drill, clamped and locked between both washers, by turning the wing nut clockwise, and to unlock the drill and remove the device from it by turning the wing nut counterclockwise. Following bone fragment repositioning, an angularly stable plate was placed over the fragments. Given that the ulna diameter in the osteosynthesis area, including the plate placed on the bone, did not exceed 1.5 cm, the drill bit section marked for drilling and limited by the drilling device was 2.0 cm long. The device was secured to the drill bit by turning the wing nut clockwise. The intraosseous canals were then drilled sequentially, and all six 3.5 mm screws were inserted, locking their heads in the angularly stable plate. The device was then unlocked and removed from the drill bit by turning the wing nut counterclockwise. The wound was rinsed with antiseptic solutions and sutured layer by layer. An aseptic dressing was applied to the wound. The postoperative period was uneventful, and the wound healed initially. We considered the surgical outcome to be good.

Features of the invention that distinguish it from the prototype

The design features (distinctive features from the prototype) of the device - limiter of bone drilling depth, are the following:

- the device consists of a 20-mm bolt (pos. 1) from the Ilizarov apparatus kit, two 18-mm washers (pos. 3 and pos. 4) mounted on it, and a wing nut (pos. 2);

- the threaded part of the bolt (pos. 1) is obliquely ground along one of its sides along its entire length from the end surface of the bolt (pos. 1) to its head to a uniformly increasing depth from 1/3 to ^1/2 of the _bolt diameter;

- one washer is straight (pos. 3), and the other is curved (pos. 4) at an angle of 15 degrees and with its concave surface faces the straight washer (pos. 32), which allows you to fix the device (Fig. 1, b) by turning the wing nut (pos. 2) clockwise on any section of the drill (pos. 5), clamped and locked between both washers (pos. 3 and pos. 4), and by turning the wing nut (pos. 2) counterclockwise - unlock the drill (pos. 5) and remove the device from it;

- on the operating table, this device is in assembled form, for which two washers are placed on the bolt (pos. 1), the first of which is straight (pos. 3), and the second is bent at an angle of 15 degrees (pos. 4), while the concave side of its bend faces the other washer (pos. 3), then a wing nut (pos. 2) is screwed onto the bolt, thereby preparing the device for use;

- use the device as follows (Fig. 1, b): having marked the estimated length of the drill section required for drilling the bone, install the device on it in such a way that the drill (pos. 5) is between both washers (pos. 3 and pos. 4), and fix this position by turning the wing nut (pos. 2) clockwise, thereby clamping the drill (pos. 5) between the washers (pos. 3 and pos. 4) and locking this device on the drill;

- remove the device from the drill (pos. 5) by turning the wing nut (pos. 2) counterclockwise.

The technical result (advantages over the prototype) of the device - limiter of the depth of drilling of bone, are the following:

- quick use of the device - with installation at any drill level;

- no need for auxiliary tools and keys, since the locking and subsequent unlocking of the device on the drill is carried out by turning the wing nut with the surgeon’s fingers clockwise and counterclockwise;

- no need for different device sizes, since the length of the bolt (20 mm) of the device allows it to be used in any range of drill diameters: from 1.5 mm to 15 mm (the drills most widely used in traumatology and orthopedics have a diameter of 2.5 to 5.5 mm);

- no need for skeletonization of the bone area on the side where the drill tip exits through its second cortical plate with maximum preservation of vascularization and periosteal osteogenesis;

- maximum preservation of vascularization, regenerative potential and resistance of bone fragments to infection helps to reduce the time it takes for a bone fracture to heal and reduces the risk of suppuration of the postoperative wound;

- reduction of the duration of surgical intervention;

- cost-effectiveness and ease of manufacture of the device, the components of which are publicly available;

- no increase in drill wear from using the device, since the contact area between the drill section and the drill-facing surfaces of both washers is sufficient to firmly lock the device on the drill without damaging its cutting edge;

- the device is reusable and does not lose its operational properties over time.

Thus, the proposed device allows for increasing the effectiveness of treatment for orthopedic and trauma patients requiring bone drilling.

Information taken into account:

1) Traumatology and Orthopedics: A Manual for Physicians / Edited by N.V.Kornilov: in 4 volumes. - V. 1: General Issues of Traumatology and Orthopedics. - St. Petersburg: Gipppokrat, 2006. - 624 pp. - pp. 303-388;

2) Traumatology: National Guidelines / Edited by G.P. Kotelnikov, S.P. Mironov - 4th ed., revised and enlarged. - Moscow: GEOTAR-Media, 2022. - 784 p. (Series "National Guidelines") DOI: 10.33029/9704-6636-0-INJ-2022-1-784;

3) Device for precision osteoperforation (Guseynov A.G.). Patent for invention No. 2410058 dated January 27, 2011;

4) Device for osteoperforation (Guseynov A.G.). Patent for invention No. 2465847 dated 11/10/2012;

5) Burykh M.P. General principles of surgical technology // Manual for surgeons. - Rostov n / D.: Phoenix Publishing House, 1999. - 544 p. - prototype device.

Claims (1)

The device is a depth limiter for drilling into a bone, characterized in that it consists of a 20-millimeter bolt from the Ilizarov apparatus kit, two 18-millimeter washers and a wing nut mounted on it, and at the same time, the threaded part of the bolt on one of its sides is obliquely ground along its entire length from the end surface of the bolt to its head to a uniformly increasing depth from 1/3 to 1/2 of the bolt diameter, one washer is straight, and the other is bent at an angle of 15 degrees and its concave surface faces the straight washer.