RU223199U1 - Device for tenolysis of the extensor apparatus of the three-phalanx finger - Google Patents

Abstract

The utility model relates to medicine, in particular to traumatology and orthopedics, and can be used for tenolysis of the extensor apparatus of the three-phalangeal muscles. fingers during surgical interventions. A device for tenolysis of the extensor apparatus of the three-phalanx finger of the hand includes a handle, a neck and a working part with a cutting edge. The neck is made in the form of a thrust platform. The working part is arched in the longitudinal plane and has a cutting edge at the end and side edges with a one-sided sharpening directed at an angle of 45° to the outer surface. The thrust pad is made of a rectangular shape with a length of 1.5-2.5 cm and a width of 1-2 cm. The length of the arc of the working part corresponds to a sector angle of 45°, in particular a circle with a diameter of 1-1.5 cm. The claimed utility model provides effective tenolysis of the extensor muscle. device of the three-phalangeal finger of the hand, reducing the time of the procedure, reduces the risk of tissue damage due to the ease of holding the device in the hand and manipulation.

Description

The utility model relates to medicine, in particular to traumatology and orthopedics, and can be used for tenolysis of the extensor apparatus of the three-phalanx muscles. fingers during surgical interventions.

The device may be useful when performing tenolysis of the extensor apparatus of the triphalangeal finger during the elimination of contractures of the finger joints.

Contractures of the finger joints are one of the most acute problems resulting from injuries to the upper limb. According to domestic authors, contractures of the interphalangeal joints occur in 25-38% of cases after hand injuries of varying severity. According to the monograph by Deykalo V.P. The cause of disability in the structure of hand injuries in 26.2% of cases was post-traumatic contractures [1].

Data from the National Electronic Injury Surveillance System in the United States showed that there were 1,130 upper extremity injuries per 100,000 people. Post-traumatic finger joint contractures have been reported as the most common complication following upper extremity trauma [2].

Contractures have a polyetiological nature and can be dermatogenic, desmogenic, tenogenic, arthrogenic and combined [3]. However, regardless of the cause, the outcome of all contractures of the joints of the fingers is a vicious position of the organ and fixation of all finger structures in a functionally disadvantageous position by scar tissue [4]. Thus, even if the extensor apparatus of the finger is intact, the tendon can be tightly fixed to the bone by rough connective tissue. The extensor apparatus of the three-phalanx finger has its own characteristics: a thin but wide tendon, muff-like adjacent to the dorsal and partially lateral surfaces of the main and middle phalanges of the finger, is represented by central and lateral bundles. The anatomical uniqueness of this structure creates surgical difficulties during tenolysis.

According to various authors, the risk of tendon rupture can reach 1-5% among all complications of the tenolysis procedure [5].

To perform this type of intervention, the lateral or palmar approach according to Bruner is predominantly used for sufficient visualization of the dorsal and volar structures of the finger [6].

Devices specifically used for this section of surgery, such as “carpal raspators” or “raspators for tenolysis of the extensor apparatus of the fingers,” are not presented on the medical instrument market, therefore, in practice, general surgical instruments are used for these manipulations.

Curved and straight raspators are known, as well as paddles used to separate soft tissues, which are also used during open surgery on the hand.

The raspator has the following parts: a working part with an edge sharpened at an angle of 45-50°; neck; support platform for finger rest; lever. The cutting edge of the raspator can have different shapes: straight; curved in an arc, convexly facing outward; curved in a concave arc. The handle of a general surgical raspator is fixed in the palm, resting the distal phalanx of the first or second finger on the working platform to ensure clear control of the applied force. The movement of the cutting edge should be directed away from you.

Straight raspators have a working part 0.6-1.0 cm wide with a cutting edge similar to an osteotome with one-sided sharpening. The lack of bending makes it difficult to perform tenolysis due to the anatomical features of the extensor apparatus of the finger, which were listed earlier, and the cylindrical shape of the phalanx; this shape of the working part limits the range of movements of the instrument, and, as a result, increases the risk of damage to the tendon along its length.

The curved raspatory has a working part sharply curved by 30°, which does not correspond to the anatomical curvature of the phalanx. The length of the working part is on average 0.5 cm, without providing tenolysis on the opposite side, thus not covering all components of the extensor apparatus of the three-phalanx finger of the hand (central and lateral bundles).

A surgical scapula is an instrument with a working part in the form of a smooth plate. A paddle for separating soft tissues has the following characteristic features: a flattened working part in the form of an elongated blade; a neck for fixing the instrument with your fingertips; tetrahedral massive handle (rounded edges).

The working part of the scapula for separating soft tissues does not have a sharp sharpening for peeling the extensor apparatus from rough scar tissue; excessive physical effort of the surgeon in the absence of a cutting working part can lead to disintegration or rupture of the tendon, or to ineffective tenolysis. The scapula does not have a bend corresponding to the anatomical shape of the phalanx of the finger. Holding the instrument is also not convenient for performing tenolysis: the neck of the scapula is too long, which reduces the ability to control the instrument when working in a small surgical field (finger phalanx); the neck of the scapula is not equipped with a support platform, which also reduces the accuracy of the surgeon’s movements.

The closest in technical essence is raspatory No. 7697 from Kohler [7], which can be used for tendon tenolysis. It consists of a handle, a neck and a working part. The handle has a curly shape. The length of the neck, round in cross section, thinner than the handle, allows, during an open tenolysis operation, to go under the extensor apparatus along its entire length in diameter and along its length. The working part, 1 cm long, is bent in a smooth arc at an angle of 30° to the neck, an osteotome-type cutting edge with one-sided sharpening at an angle of 45° is presented only at the end of the working part.

The disadvantage of the device chosen as a prototype is the low efficiency of tenolysis of the tendons of the three-phalanx finger. This is due to the fact that the neck, on which the surgeon rests with the supporting finger (the distal phalanx of the first or second finger), is made with a round cross-section, thin, which does not provide a sufficient support surface for the supporting finger, does not allow manipulation of the device accurately, under control, thereby increasing the most risks of damage to anatomical structures. In addition, making the working part in the form of a short arc, with sharpening only from the end of the working part, does not allow tenolysis to be carried out quickly and accurately, in “one movement” for contractures of the three-phalangeal fingers of the hand (when the extensor apparatus is fixed to the bone along its entire length, and along length and width). This form of the working part leads to the need to carry out movements repeatedly, changing the angle of application of the instrument, moving the neck under the extensor apparatus, which also increases tissue injury. Considering the limitations for free manipulation under conditions of standard lateral or palmar access according to Bruner, the insufficient support surface, coupled with the non-optimal shape and sharpening of the working instrument for the three-phalanx finger, leads to a sharp decrease in the precision of movements and, accordingly, a decrease in the effectiveness of tenolysis, an increase in tissue injury and operation time.

The task to be solved by the claimed utility model is the development of a device for tenolysis of the extensor apparatus of the three-phalanx finger, which will increase the efficiency of tenolysis, reduce the time of the procedure, and reduce the risks of tissue damage.

In order to select the optimal parameters of a device for tenolysis of the extensor apparatus of the three-phalanx finger, the authors conducted studies of analogue devices of various configurations. The experiments used a plastic dummy of the second ray, represented by the second metacarpal bone, the main, middle and distal phalanges of the second finger. The dummy was 3D printed based on a computed tomography scan of the right hand. Using a medical rubber glove fixed proximally and distally with adhesive tape to the metacarpophalangeal and proximal interphalangeal joints, respectively, the extensor apparatus of the finger was reconstructed at the level of the main phalanx. The dummy is fixed with two iron clamps on the supplies (Fig. 1). Next, the tenolysis process was simulated using alternately the three available raspators.

The first to use was a straight rasp with one-sided sharpening at the end of the working part, without a stop pad (Fig. 2, 3). During the experiment, the following disadvantages were identified: a high risk of damage to the extensor apparatus due to the lack of anatomical bending of the working part of the raspator, inconvenience of fixing the instrument in the surgeon’s hand (very thin handle), reduced maneuverability of the instrument due to the lack of a stop pad for the finger, a handle of small diameter; the absence of a cutting edge along the entire edge of the working part of the instrument makes tenolysis in the proximal and distal directions difficult (Fig. 4).

Next, we used a rasp, bent along an arc of a 10° sector of a circle, with one-sided sharpening of the working part at the end (Fig. 5, 6). During the experiment, the risk of damage to the extensor apparatus was low, however, the other above-mentioned disadvantages of the first raspator were inherent in this instrument to the same extent (Fig. 7).

The third instrument had a thrust platform for the distal phalanx of the finger, a neck (Fig. 8, 9) with a thrust platform and a straight working part curved at an angle of 100° to the neck of the instrument, an osteotome-type cutting edge along all edges of the working part. The following disadvantages have been identified: the long neck reduces the maneuverability and control of the instrument when performing tenolysis in a limited anatomical area; the working part (Fig. 10) does not cover the entire area of tenolysis, the bend of the transition between the neck and the working part corresponds to the anatomical bend of the phalanx, but when located on the bone of the instrument, the working part falls only on ½ of the extensor apparatus in diameter, which implies ineffective tenolysis.

Also, during the experiment, five rays were printed on a 3D printer (the second ray, represented by the metacarpal bone and three phalanges - main, middle, distal) based on computed tomography of the right hands of five different patients. When measuring experimental ray models on a cross-section, it was revealed that the average value of the phalanx arc corresponds to the arc of a sector of a circle of 45°.

During the experiment, it was concluded that the shape of the working part of the device, optimal for tenolysis of the extensor apparatus of the triphalangeal finger, should correspond to the average shape and size of the main phalanx of the triphalangeal finger. Taking into account the fact that the extensor apparatus is adjacent to the dorsal and partially lateral surfaces of the phalanx of the fingers, the bend of the working part of the device must correspond to the dorsal arch of the main phalanx. When measuring a cross-section of an experimental beam model, it was revealed that the average value of the phalanx arc corresponds to the arc of a 45° sector of a circle. The working surface of this form will correspond to the anatomical shape of the main phalanx and will allow tenolysis of the extensor apparatus of the finger to be performed effectively along its entire length.

During the experiment, it was revealed that in order to increase the efficiency of tenolysis, reduce the risk of damage to anatomical structures, and increase the ergonomic properties of the raspator, the following type of device is required: a large handle that turns into a neck, which is made in the form of a thrust platform for the distal phalanx of the first or second finger of the surgeon’s hand, a working part of the device is curved in accordance with the anatomical feature of the bend of the main phalanx of the finger (Fig. 11, 12, 13), the working part has a cutting edge (with one-sided sharpening) along the entire edge of the working part. Depending on the anthropometric parameters of the hand of a particular patient, the shape of the working part (the length of the arc and the shape of the arc, determined by the cross-sectional diameter of the phalanx of the operated finger) corresponds to the arc of a sector of 45° of a circle with a diameter of 1-1.5 cm.

The technical result of the claimed utility model is to provide the possibility of safe and anatomical tenolysis with ease of use.

The technical result is achieved due to the fact that in the device for tenolysis of the extensor apparatus of the three-phalanx finger of the hand, including a handle, a neck and a working part with a cutting edge at the end, the cutting edge has a one-sided sharpening directed at an angle of 45° to the outer surface, according to the useful model, the neck is made in the form of a thrust pad, the working part is arched in the longitudinal plane and has a cutting edge on the side edges with one-sided sharpening directed at an angle of 45° to the outer surface.

In particular embodiments of the claimed device, the thrust pad is made of a rectangular shape with a length of 1.5-2.5 cm and a width of 1-2 cm; the length of the arc corresponds to a sector angle of 45°, in particular from a circle with a diameter of 1-1.5 cm.

Advantages of the proposed device:

1. The working part is smoothly curved in an arc, in particular a sector of a circle of 45°, which corresponds to the anatomical shape of the main phalanx of the three-phalanx finger and allows tenolysis of the extensor apparatus to be performed using standard incisions (lateral, palmar according to Bruner), eliminating the need for additional incisions;

2. The cutting edge is made along the edges of the working part, including its end, which allows movements in the transverse and longitudinal directions relative to the axis of the finger, thus ensuring effective tenolysis of the entire extensor apparatus;

3. The outer surface of the working part is sharpened at an angle of 45° relative to the inner surface, so the inner surface slides along the bone with the sharp part, peeling the extensor from the bone without the risk of damaging the extensor apparatus;

4. The neck is made in the form of a thrust platform, allowing the distal phalanx of the first or second finger to be applied, which stabilizes the position of the device in the surgeon’s hand and makes it possible to perform all movements with extreme precision and accuracy in a limited anatomical area and taking into account the anatomical shape of the working part, which fits tightly phalanx;

5. The proposed device is easy to use and anatomically shaped, allowing to minimize the number of instruments used in manipulation, and also eliminates the need for additional incisions;

6. The possibility of sterilization and reuse determines the economic feasibility of using the claimed device for tenolysis of the extensor apparatus of the three-phalanx finger.

The claimed device is illustrated by drawings, where:

Fig. 1 - A dummy of the second ray, including the metacarpal bone, the main, middle and distal phalanges of the second finger, a recreated extensor.

Fig. 2 - General view of the device involved in the experiment (straight raspatory), front view.

Fig. 3 - General view of the device involved in the experiment (straight raspatory), side view.

Fig. 4 - Experiment (recreation of the tenolysis procedure of the extensor apparatus of the main phalanx) with a direct raspatory on a dummy of the second ray.

Fig. 5 - General view of the device involved in the experiment (curved raspatory), front view.

Fig. 6 - General view of the device involved in the experiment (curved raspatory), side view.

Fig. 7 - Experiment (recreation of the tenolysis procedure of the extensor apparatus of the main phalanx) with a curved straight raspatory on a dummy of the second ray.

Fig. 8 - General view of the proposed device (raspatory), front view.

Fig. 9 - General view of the proposed device (raspatory), side view.

Fig. 10 - Experiment (recreation of the tenolysis procedure of the extensor apparatus of the main phalanx) with the proposed raspatory on a dummy of the second ray.

Fig. 11 - General view of the claimed device, side view.

Fig. 12 - General view of the claimed device, top view.

Fig. 13 - General view of the claimed device, bottom view.

Fig. 14 - Recreation of the procedure for tenolysis of the extensor apparatus of the main phalanx with the proposed raspatory on a dummy of the second ray.

Fig. 15 - Claimed device, top view.

Fig. 16 - Claimed device, side view.

Fig. 17 - Section of the working part of the device by plane A-A and schematic location relative to the finger bone.

The claimed device (Fig. 11, 12, 13) is made of metal or a metal alloy approved for use in traumatology and orthopedics and contains a handle 1, a neck 2 made in the form of a thrust pad, as well as a working part 3 with a cutting edge along all edges working part, including the end (Fig. 15, 16).

Handle 1 is made in the form of a straight cylinder, widened and rounded at the base. The neck 2 starts from the distal part of the handle 1, extends from the handle in a horizontal plane and is made in the form of a thrust platform, for example a rectangular shape, the length of which is 1.5-2.5 cm and a width of 1-2 cm. The working part 3 starts from the center neck 2 (thrust platform), extends from it 2 in the horizontal plane and in the lateral projection has the shape of an arc of a 45° sector of a circle. The outer surface 4 (convex) of the working part 3 is sharpened (beveled) to the inner surface 5 (concave) at an angle of 45°, respectively, the cutting edge is made along all edges of the working part 3, including its end.

This device is used as follows: the surgeon places the first or second finger on the thrust pad (neck 2), clasps the handle 1 with the palm and four fingers, this position of the surgeon’s hand ensures stability and control of the device, increases the accuracy of work in a relatively small surgical space (Fig. 14 ).

After a standard incision in the area of the main phalanx of the finger (a shaped incision according to Bruner or a linear incision along the neutral lines of the main phalanx), access is made to the extensor apparatus of the finger, the device is positioned in the surgeon's hand in the above manner, working part 3 is inserted above the bone of the main phalanx under the extensor apparatus of the finger , perform a movement “from yourself”, in such a way that the working part 3 of the device moves transversely relative to the axis of the finger and slides between the bone of the main phalanx and the extensor apparatus due to the sharpened end of the working part 3 of the device, without changing the position of the device, then perform movements in the longitudinal direction finger “distally” and “proximally” due to sharpening along all edges of the working part 3, these movements perform tenolysis of the extensor apparatus of the finger along its entire length. The anatomical bending of the working part 3 allows for effective tenolysis taking into account the cylindrical shape of the bone of the main phalanx and the extensor apparatus of the finger of the hand, which is muff-like adjacent to its dorsal and partially lateral surfaces, and the wedge-shaped one-sided sharpening of the working part 3 minimizes the risk of damage to the tendons (central and lateral bundles) of the extensor apparatus finger of the hand.

Thus, the claimed utility model provides effective tenolysis of the extensor apparatus of the three-phalanx finger, reduces the procedure time, and reduces the risk of tissue damage due to the ease of holding the device in the hand and manipulation.

Bibliography:

1. Deykalo, V.P. Clinical and statistical aspects and medical rehabilitation of hand injuries: [monograph] / V.P. Deykalo; Ministry of Health of the Republic of Belarus, Vitebsk State Medical University. - Vitebsk: [VSMU], 2003. - 125 p.

2. Ootes, D., Lambers, K. T., & Ring, D. C. (2012). The epidemiology of upper extremity injuries presenting to the emergency department in the United States. Hand (New York, N.Y.), 7(1), 18-22. https://doi.org/10.1007/s11552-011-9383-z.

3. Wang, E. D., & Rahgozar, P. (2019). The Pathogenesis and Treatment of the Stiff Finger. Clinics in plastic surgery, 46(3), 339-345. https://doi.org/10.1016/j.cps.2019.02.007

4. Rongières M. (2018). Management of posttraumatic finger contractures in adults. Hand surgery & rehabilitation, 37(5), 275-280. https://doi.org/10.1016/j.hansur.2018.06.003

5. Kher S, Graham DJ, Symes M, Lawson R, Sivakumar BS. Outcomes of Isolated Digital Flexor Tenolysis: A Systematic Review. J Hand Surg Asian Pac Vol. 2021;26(4):580-587. doi:10.1142/S2424835521500557

6. Griffin M, Hindocha S, Jordan D, Saleh M, Khan W. Management of extensor tendon injuries. Open Orthop J 2012;6:36-42. doi: 10.2174/1874325001206010036. Epub 2012 Feb 23. PMID: 22431949; PMCID: PMC3293224.

7. Color-Coded Raspatory 17.5 cm, No. 7697. Official KOHLER Dental Instrument Store. Dental instrument KOHLER, http://www.kohlermed.ru/?p=3511, access date 10/25/2023.

Claims (4)

1. A device for tenolysis of the extensor apparatus of the three-phalanx finger of the hand, including a handle, a neck and a working part with a cutting edge at the end, wherein the cutting edge has a one-sided sharpening directed at an angle of 45° to the outer surface, characterized in that the neck is made in the form of a persistent platform, the working part is made arc-shaped in the longitudinal plane and has a cutting edge on the side edges with one-sided sharpening directed at an angle of 45° to the outer surface. 2. The device according to claim 1, characterized in that the thrust platform is made of a rectangular shape with a length of 1.5-2.5 cm and a width of 1-2 cm. 3. The device according to claim 1, characterized in that the length of the arc of the working part corresponds to a sector angle of 45°. 4. The device according to claim 3, characterized in that the length of the arc of the working part corresponds to a sector angle of 45° of a circle with a diameter of 1-1.5 cm.