BE1020435A4 - TELESCOPIC INTRAMEDULAR HYDRAULIC DISTRACTION SYSTEM FOR EXTENSION, TRANSPORTATION AND COMPRESSION OF BOT AND WEAK PARTS. - Google Patents

Description

Telescopic Intramédullaire Hydraulic Distraction system for extension, transport and compression of bone and soft tissue DESCRIPTION:

GENERAL

A medical device is described useful for moving a segment of human bone with a surrounding sheath of soft tissue over an intramedullary marrow by progressively increasing the distance between the upper and middle bone fragment. This creates progressive bone tissue between the two bony fragments by stimulating the biological process of distraction osteogenesis.

If the purpose of the displacement is to transport a bone fragment without increasing the distance between the main bone fragments, the described implant serves as a transport nail (locking pin). If the displacement is intended to progressively increase the distance between two main bone fragments, it has the function of extension nail (extension pin).

The medical device consists of two tubes or cylinders in which a fixed rod can move in the distal direction (extension nail) under hydraulic pressure or a double-walled metal tube in association with a longitudinally oriented slot arranged in the middle part of this cylinder to guide a transport screw (transport nail). Below the slot there is a separate cross opening to fix the nail at the end of the distraction procedure. Both the slot and the transverse opening under the slot are in the same plane.

Proximally, the metal tube is anchored in the bone with separate screws. The screw fixation of the rod to the bone is done with identical openings at the distal end of the nail. These cross openings can lie in different planes.

A pressure chamber is located in the head piece (upper part of the cylinder) and acts as an actuator for the construction and maintenance of the necessary hydraulic pressure. The piston piston or piston is located under the pressure chamber (middle part of the cylinder)! which, for the transport nail, presses directly on the transport screw which - after insertion of the transport nail - is fixed by the slot on both sides of the bone fragment to be transported This transport screw allows displacement of the bone segment over the nail. directly on the fixed bar to achieve extension.

The pestle is hermetically separated from the cylinder wall by a shock-absorbing system that is made either from plastic or metal.

A one-way valve in the valve housing (proximal part of the head piece), made of plastic or metal, ensures that no liquid retrograde can flow back from the pressure chamber and contributes to the creation of a pressure chamber with an anti-reflux effect proximally.

A feed tube in metal or polymer connects between pressure chamber and proximal portion of the head piece. The supply of a non-expandable liquid via the valve housing to the pressure chamber (for the build-up of pressures) is via a coupling mechanism proximal to the valve housing. This is formed by a tube that connects either via the skin to an external reservoir or internally ( subcutaneous] is provided with a disposable reservoir.The tube that is brought out through the skin is finally provided with an external coupling for the telescopic control: mechanical hand pump or piezoelectric drive system.

To adjust the transport nail to the length of the bone, a mechanism was built in of blocking between rod and outer jacket of the cylinder using a blocking screw.

Multiple anti-rotatory locking mechanisms have been designed as mechanisms to ensure uni-directional translation of the bar and to prevent risk of collapse due to pressure loss after extension. An option is a locking pin mounted on a spring to drag the nail along individual oval-shaped recesses.

An alternative anti-reflux mechanism consists of a toothed locking plate (Clavet) made of Co-Cr alloy (phynox, commercial) that only allows movements in one direction (distal) and is constructed in such a way that it is complementary to a grooved recess in the fixed tube.

A second alternative to an anti-rotation blocking mechanism is based on a ratchet that allows translation (unidirectional movement) of the fixed rod in the cylinder / tube.

Multiple separate interchangeable pieces (straight or curved) can be connected to the distal end of the marrow pin to simulate different bone lengths. Expandable plastic plugs in the distal openings of the marrow pin can act to anchor the screws.

BACKGROUND

This invention is intended for bone transport and bone extension in the lower and upper limb. This invention can be used in bone defects after trauma, tumor resection or infection. Bone defects can also *> arise during the treatment of non-healing fractures (due to resection of dead bone tissue). This technique is also suitable for fixation of fractures that are difficult to heal (non-union, pseudo-arthrodesis).

In the axial transport of human bone, a bone fragment is moved over a marrow pin via hydraulic technology (transport nail). The bone movement can take place in two directions: towards proximal (compression) or towards distal (distraction). The distraction and compression nails each have several openings in their upper and lower parts. These openings can be in different planes depending on the indication. connecting Through these cross openings, screws can connect the transport nail to the bone. These openings can be provided with expanding plugs in plastic or hard material, to better anchor the screws in the marrow pin.

When extending human bone, the two parts of the extension nail (fixed rod and cylinder) are fixed to the bone with screws.

After placing the transport nail / extension nail, every day, via the connection of a telescopic drive (eg external pump), the pressure in the hydraulic chamber is increased once. This pressure increase pushes the tamper (and the transport screw for transport nail) to distal. When this shift / extension is slow (0.5 to 1.3 mm / day), bone tissue grows spontaneously in the treatment area. It is possible to move the bone up to 8 centimeters (transport nail) or extend it (extension nail). The hydraulic pressure can also be supplied are placed via an internal (subcutaneous) reservoir, which reservoir must then be connected to the hydraulic pressure chamber with a supply tube.

There are currently three systems applicable worldwide: (a) the extramedullary mechanical system such as the ring fixator from Gavriil A.

Ilizarov (US patent No. "4615338), (b) the intramedullary mechanical extension nail from JM Guichet (Albizzia nail)," ISKD nail "from J. Dean Cole (US patent 310-533-9966) and the" drive device " from Alexander Bliskunov (US Patent No. 7530981), and (c) the electromotive extension nail from A. Betz (Fitbone).

Currently, one system is applicable worldwide: the extramedullary ring fixator from Gavriil A. Ilizarov (US patent No. 4615338). In the context of Ilizarov, the limb is fixed by means of various externally visible rings that are connected to the bone by means of thin metal pins. These metal pins go straight through the limb and are fixed to the ring on either side of the limb. To guarantee the stability of the structure, these metal pins are first tensioned (100 kg). Only then are they fixed on the metal ring with connecting nuts. At least two metal pins are required per ring, which are fixed to the ring at an angle of at least 40 ° from each other. With the Ilizarov method, the bone is moved via externally visible wire rods. By moving some nuts on the threaded rod one can move the rings apart or closer.

The advantage of this technique is its reproducibility and robustness. The disadvantage, however, is patient unfriendliness and the complication rate that goes up to 79%. The most important complications are 1. Pain during the extension (the metal pins have to cut through the skin to allow distraction between the rings) 2. Infections (the long-term connection with the skin always causes a contamination of the metal pins) 3. Bending of the bone. After removal of the Ilizarov framework, the newly formed bone is not always of good quality, which may induce bending of the limb.

4. Psychological problems that can arise in the patient due to the long-term presence of the externally visible frame on their arm or leg.

With the other mechanical extension nails, the limb must be turned 54 times to activate the double gear system in the nail.

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With the Albizzia nail, the operated bone had to be turned up to 20 ° before the gear system was activated. With the ISKD nail this torsion is reduced to 3 °. The advantage of the mechanical systems is that the whole is built into the patient, which in theory reduces the chance of infections. A disadvantage of the Albizzia nail is the large turning angle that is required to activate the gear system. The latter considerably reduces patient comfort. With the ISKD nail the angle of rotation is smaller (3 °) but gives the specific disadvantage that the preprogrammed nail can run wild. With a sudden extension of several centimeters in one day. This sudden extension of the limb can cause paralysis and delayed bone healing. Both nails have the disadvantage that they are straight, which makes insertion into a bent bone more difficult.

The electromotoric nail (fitbone) shares the advantage with the mechanical extension pin that it can be placed completely internally (activation by electro-mechanical impulses). Rust and collapse of the extension are noted as a major disadvantage. This rusting gave rise to some pseudotumors.

The proposed concept was developed to solve the problems mentioned above. The objective is to design an easy-to-use extension pin that uses the well-known method of (non-compressible) fluid mechanics to achieve a controlled displacement of bone and soft tissue through pressure transfer (hydraulics) according to Hagén poiseuille. such an implant described by Götz & Schellmann but never put into practice. "Archiv. Orthopädische Unfall-Surgery 82: 305-310, JF Bergmann Publishing Munich (1975]".

The TIHLS concept was introduced (Fig. 1] by animal experimental research on sheep by means of manual pressure increase (K.N. Vanden Weghe].

The Inductive coupling between two coils of the concept of magnetic extension nail (integrated coil) from Vito (Van Tichelen, • »

Ceuterick] and Optidrive (De Quecker] gave uncontrollable and robust displacement influenced by metal objects in the environment, making these derived models unusable, and it was only in 2003 that the concept of K. Vanden Weghe was introduced for the first time as an extra-medullary arrangement. human application (Fig. 2) designed in collaboration with UZLeuven (P. Reynders). This design was the cradle for the intra-medullary development of the following years and several consecutive models were developed, first for extension, later for transport of bone segments. versions (such as from rigid transdermal instrument tube to a flexible inlet; from classical anterograde valve to additional mechanical protection for collapse by means of

locking, anti-rotation technique and methods such as locking pins, blocking bars, clavet and ratchet] were the result of years (2005-2008) R&D of TIHLS use in clinical test phase (M. Peter-John].

The distraction pins are designed for the femur and lower leg, but the principle can be applied to any other leg and can also be used with other medical devices to achieve similar goals (vertebral corrections in scoliosis). The illustrations are not exhaustive.

TECHNIC

A medical device is designed to transport or extend a human bone segment and its soft tissue mantle (Fig. 3 and Fig. 4] (Fig.

5 and FIG. 6] by metered increase in fluid pressure in the pressure chamber of the marrow pin. By applying an increase in pressure via external (extracorporeal) or internal (intracorporeal) pressure, the rod (nail) is pushed out of the tube or butterfly tube, since the transport nail (Fig. 3 and Fig. 4) is fixed at the ends with the aid of screws, a bone segment separated from the upper and lower bone portion by an ostéotomy (Fig. 3] can slide down over the nail, resulting in a bone displacement (Fig. 4). With the extension nail (Fig. 5) good anchoring to the bone is responsible for distraction, resulting in an extension of bone (Fig. 6). The space that is created between the bone fragments is progressively filled with its own bone tissue (Fig. 4 and Fig. 6 after procedure)

Initially, the doctor removes the soft marrow tissue in the bone by using milling cutters mounted on a flexible support rod. The bone is run through (ostéotomy) and the transport nail or extension nail is inserted. The transport nail or extension nail is fixed to the bone via screws at its ends. An external plastic or metal tube allows the doctor to introduce sterile fluid under pressure to activate the actuator.

For this, he uses an external pump that can insert liquid into the transport stud manually, electronically or via piezo-electric mechanism. Use can also be made of internally arranged liquid reservoir under pressure which can autonomously effect the pressure increase in the extension or locking pin.

FIG. 3, FIG. 4, FIG. 5 and FIG. 6 illustrate the general aspect of the extension nail (Fig 5 and Fig. 6) and transport nail (Fig. 3 and Fig. 4) in an upper or lower leg (see figure). The marrow nails are provided with a pliable, thin supply tube (1) that can be manufactured in metal or any other plastic material and that is biocompatible for use in the human body (316L or polymer in polyimide). In the proximal part of the butterfly, for both the transport and extension studs, there is the head piece (2) with the check valve housing and the proximal locking openings in the coronal plane (5) and in the sagital plane (3) and below it. actuator or pressure chamber (11). The transport and extension nail is fixed to the bone via these locking openings with the aid of osteosynthesis screws (4). These locking openings may be provided with a locking mechanism, such as an expandable metal or polymer plug that fixes the screws in the marrow pin. A longitudinally oriented slot (6) is located in the middle part of the butterfly. The transport screw (7) is placed in the upper armpit of this slot. Upon activation of the transport nail, the ram (18) presses against the transport screw (7). Just below the slot there is a cross opening (9).

At the end of the bone transport, the displaced bone segment is additionally fixed by a blocking screw (10). This screw is

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placed under the skin through the bone in the transverse opening (9) and prevents the bone segment from jumping back. A mechanism is provided in the lower part of the butterfly to adjust the extendable rod / nail (8) to the length of the bone. At the distal end of the extendable rod / nail, distal locking openings (12) are provided for osteosynthesis screws (4) to fix the transport and extension nail to the bone. These openings can be provided with a blocking mechanism (expanding plug) that blocks the screws in the transport nail. These expanding plugs may be resorbable in metal or non-resorbable polymer. The cylinder consists of a double-walled structure (13 and 14) with the extendable rod for both types of nails. Bone growth (15) during progressive distraction (transport nail) or after extension (extension nail) occurs as a result of bone movement.

FIG. 7, FIG. 8 and FIG. 9 are detailed drawings of the proximal part of the cylinder for both the transport and extension stud. It contains a head piece (2), pressure chamber (11) and piston or pistil (18). The supply tube or filler pipe (1) is pliable (flexible), and can be made with any biocompatible material, either plastic (polyimide) or metal (316L). This tube supplies sterile fluid from an internal reservoir or is connected to an external matching coupling, for example for connecting an external pump. This flexible hose is held centrally by a cover screw (Fig. 7, 19; Fig. 8, 19; Fig. 9, 19a) with a teflon jacket (Fig. 7, 19; Fig. 8, 19; Fig. 9,19b). Via a nut (Fig. 7, 20; Fig. 8, 20; Fig. 9, 20b) the conical coupling (Fig. 7, 20; Fig. 8, 20; Fig. 9, 20a) is pressed onto the flexible supply hose and fitted in the internal valve housing (21) in the middle part of the head piece. The proximal part of the head piece (2) is provided with 2 to 4 positioning notches (6) to correctly carry out the placement of the directional arm in the marrow pin. This directional arm serves to lock the proximal part of the marrow pin. The non-return valve (13) with spring (22) is locked in the lower part of the valve housing (21) by means of the locking screw (16).

To lose pressure. To avoid this, a seal (23) is provided between the valve housing and its container with a biocompatible elastomer (or peek ring). A channel (24) connects the valve housing (21) with the pressure chamber (11). The connecting channel (25) runs through the distal portion of the head piece (12) where the proximal locking openings (3] and (5) are located.The pressure chamber (11] is located in the double-walled cylinder (13] and (14] where the long piston or pistil (18]. The long piston is pushed downwards by the accumulated fluid pressure (in a direction away from the upper marrow part). This long piston consists of a plunger head (18] and a plunger tail (29] The plunger head is provided with a double 7 system of annular elastomeric shock absorbers (26] and two stabilizers in peek (Fig. 23, 27] and a guide ring (Fig. 23, 28], which guarantee a good seal between piston and fluid chamber. This perfect seal is necessary to maintain a pressure gradient between the check valve (13) and the piston or piston (29).

FIG. 10a, FIG. 10b, Fig. 10c is a representation of the head piece with lead-in, conical coupling, locking openings, valve housing, produced in one piece.

FIG. 11 is a detailed representation of the center portion of the butterfly nail of the transport stud with illustration of the piston or pistil (18). The long piston (pusher) that is pushed to distal pressure beyond the double-sided longitudinal slot (6), and presses on the transport screw (7) that is located transversely in the bone segment, which in turn takes the bone segment with it. Just below the slot, there is a transport bore (9) where a fixation screw (10) is placed at the end of the bone distraction (blocking) procedure.

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FIG. 12 illustrates the distal aspect of the transport nail with the transition from the bone transport portion (30) and the extendable bar / nail (8). Here the rod / nail (8) can be manually slid out of the cylinder (31) manually, according to the arrow, for the purpose of adapting the extension nail to the length of the bone.

FIG. 13 and FIG. 14 illustrate the possibility of attaching attachments. either straight or curved. Different attachments can also be provided which can extend the length of the full bar (8). This extension (33a) is pre-fixed on the fixed rod (8) with a locking screw (34) (detail, see Fig. 19). These extensions can be provided with openings or slots. Multiple screws can be inserted into these openings or slot to give the distraction pin the necessary stability. These attachments are straight or slightly bent to follow the bend of the bone.

FIG. 15 illustrates the shifts of the distal full bar from the double-walled cylinder. It also clarifies the mechanical locking system that, together with the non-return valve, prevents the sliding-in rod from collapsing.

FIG. 15a and FIG. 15b illustrates an enlargement of the lower part of the inner cylinder (13). Its inner wall has asymmetrical recesses (33b). A mechanical locking mechanism, consisting of one or two round bars (36), pushed apart by a spring (37). These spring-locking pins (36 and 37) slide over the serrated wall of the inner cylinder (13). Each time these locking pins end up in a recess, this prevents the recoil of the fixed rod (8).

FIG. 16a, FIG. 16b, FIG. 17a, FIG. 17b and FIG. 17c illustrate the distal aspect of the cylinder with the rod (8) located in the double-walled cylinder (13 and 14) of the transport nail and advancing at the extension nail.

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This full rod is provided along with a shallow slot (38) along which an oval locking plate or slot (39) fits. This oval locking plate is secured in an oval recess in the inner cylinder (13). The full rod (8) with longitudinal slot (38) can slide along a locking plate (39) and provide sufficient rotational stability to the rod / nail. A plug (45) can be used for locking with a fixation screw and extra stability after bottling. The oval locking plate (39) can be equipped with a few round locking pins (44) mounted on a spring (41). These locking pins drag over a serrated base of the spigot slot. With these locking pins a recoil of the fixed rod can be prevented.

FIG. 18a and 18b illustrate an alternative: This clavet (40) made of co-cr alloy (phynox) contains a toothed locking pin (41) sunk into a recess of the clavet and can be projected out by means of. a spring (42), The locking pin of the clavet is congruent with the congruent slot of the rod (8] provided with notches (43)

FIG. 19 represents a blocking screw (45) and is used to lock the extendable portion of the transport stud. Through this mechanism, the length of the transport nail can be adjusted to the length of the bone. The thick portion of the screw rests against the outer jacket or husk (14) and in a recess of the full rod (38).

FIG. 20a, FIG. 20b, FIG. 20c, FIG. 21a, FIG. 21b, FIG. 22a and FIG. 22b. A ratchet (45) consisting of an opening rod (46) for a fitting rod and a foot (47) that fits bilaterally into a mutual toothed groove (48) embedded in a longitudinal recess of the fixed rod (2) and by means of e.g. the described rod (50), fitting into its opening (46), held in place by fixation (through drill holes) on both diametrical sides of the metal cylinder (49). By hydraulic pressure build-up, the fixed rod is advanced over the ratchet along the described toothed groove (48) on both sides of the longitudinal slot in the rod. This acts as an anti-reflux mechanism.

FIG. 23a and FIG. 23b illustrate an overview of the cylinder with various components described in the previous figures.

DRAWINGS:

Fig 1: Animal experimental designs on sheep (2000 - 2001)

Fig 2: First extra-medullary design for human use [2003]

FIG. 3a: Transport nail. Application before extension: Frontal View Lower leg + TIHLS

FIG. 3b: Transport nail. Application before extension: Lateral View TIHLS Fig. 4a: Transport nail. Application after extension: Frontal View Lower leg + TIHLS

Fig 4b: Transport nail. Application after extension: Lateral View TIHLS Fig. 5a: Extension nail. Application before extension: Frontal View Lower leg + TIHLS

FIG. 5b: Extension nail. Application before extension: Lateral View TIHLS Fig 6a: Extension nail. Application after extension: Frontal View Upper leg + TIHLS

Fig 6b: Extension nail. Application after extension: Frontal View TIHLS Fig. 7: Proximal part of the cylinder - Forward-backward view Fig. 8: Proximal part of the cylinder - lateral view

FIG. 9: Head piece: Proximal part: insert flexible tube in conical structure. 10a: Head piece: conical coupling, locking openings, valve body: one-piece production - Top view

FIG. 10b: Head piece: conical coupling, locking openings, valve body: ^ * one-piece production - Forward-backward view

FIG. 10c: Head piece: conical coupling, locking openings, valve body: one-piece production - Lateral view

FIG. 11: Transport nail. Middle part

FIG. 12: Transport nail: Adjustment of the extension bar to the length of the bone

FIG. 13: Distraction nail. Attachments. Frontal view

FIG. 14: Distraction nail. Attachments. Lateral view

FIG. 15a: Mechanical locking (distal]. Locking in advance

FIG. 15b: Mechanical locking (distal] Locking - Detail

FIG. 16a: Oval shaped recess bar, locking plate, key - longitudinal Fig. 16b: Oval shaped recess, locking plate, key - cross section. 17a: Anti-reflux: Shallow slit Fig. 17b: Anti-reflux (locking plate, spi) and anti-rotation (locking pin)

FIG. 17c: Anti-reflux (locking plate, spi) and anti-rotation (locking pin) - detail

FIG. 18a: Clavet - Long sight

FIG. 18b: Clavet - Cross section

FIG. 19: Locking screw

FIG. 20a: Ratchet - Overview

FIG. 2Öb: Pin for fixing ratchet in tube - longitudinal view Fig. 20c: Pin for fixing ratchet in tube - cross view Fig. 21a: tube (cylinder) - longitudinal view Fig. 21b: Rod with recess for ratchet - longitudinal view Fig. 22a: Ratchet system: Ratchet

FIG. 22b: Ratchet system: Ratchet-containing rod - longitudinal overview Fig. 23a: Transport nail: Cylinder with different components. 23b: Transport nail: Spi-slot and locking plate - detail

FIG. 24: Accessories Head piece: plunger head, non-return valve, spring, flexible inlet (polyimide)

FIG. 25: lengthening Nail, Production 2006, J. Van Bael - tube with extended nail injteflon and original locking pin

FIG. 26: lengthening Nail, Production 2006, J. Van Bael - tube with retracted * * nail and metal supply tube, ending with swagelok coupling for hand pump

Fig: 27: lengthening Nail, Production 2006, J. Van Bael - nail, cylinder with metal supply tube ending with swagelock coupling, plunger (head and tail)

FIG. 28: lehgthehing Nail, Production 2006, J Van 'Bael - Cylinder with supply tube and swagelock coupling

Claims (7)

1. The created space after the displacement of bone pieces is progressively filled with their own bone tissue; The medical device consists of a metal tube (cylinder) with a longitudinal slot in the middle segment. The proximal portion of the distraction nail is attached with screws to the proximal bone portion and the distal portion of the distraction nail is attached with screws to the distal bone portion; The hydraulic pressure chamber of the metal cylinder is in contact with the upper part of the extension or transport nail; A non-return valve is located between the hydraulic pressure chamber and the delivery pipe; The supply tube is connected externally to a coupling system or internally to a fluid reservoir and made of a biocompatible flexible material; and is specially fixed with a conical sleeve and nut in the proximal portion of the transport and extension stud; The non-return valve is mounted on a resilient mechanism located in a housing and the housing of which is screwed into the proximal portion of the transport and extension nail; Provided with an elastomeric seal; A center piece with a feed-through channel through which openings are drilled in different planes, in which plugs can be provided that expand when screws pass through; A pressure chamber where the fluid is pressurized and sealed by a stamper provided with x-shaped sealing rings that can retain a pressure gradient between the actuator and the distal side of the stamper; 2. The medical device described in claim 1. also contains a double-walled hollow tube and a longitudinal slot in its middle portion and a circular opening just below the longitudinal slot, in the same plane as the slot. 3. The medical device described in claim 1. also contains a full rod that is slit longitudinally and can move in the double-walled hollow tube; 4. The medical device described in claim 1. also includes an oval locking plate, clavet, or ratchet that slides into the slotted full rod and is fixed in an oval space in the inner wall of the cylinder and ensures rotational stability; 5. The medical device described in claim 1. also contains in its distal part a mechanical blocking system that prevents axial collapse of the nail; The mechanical blocking system is located in a recess in the full rod and consists of two round locking pins mounted on a spring; The mechanical blocking system moves over a serrated edge on the inner wall of the cylinder; 6. The medical device described in claim 1. also contains a distal full extendable rod, the length of which can be extended with extensions; These extensions are provided with multiple transversal> * openings; The extensions can be provided with a slot in which a locking screw fits; These extensions can be straight or curved depending on the anatomical requirement of the marrow canal; 7. The medical device described in claim 1. also contains an external drive system that can drive the internal actuator via mechanical, electromagnetic or piezoelectric means; The medical device may also have an internal drive system that drives the internal actuator via mechanical, electromagnetic or piezoelectric means.