RU2826771C1 - Minimally invasive method of osteosynthesis of medial fractures of femoral neck - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: minimally invasive method of osteosynthesis of medial fractures of femoral neck includes the following stages: under X-ray control into upper and lower poles of femoral head coaxially to femoral neck from subtrochanteric zone two wires are delivered parallel to each other, successively removing wires, in the formed bone canals according to the length of the femoral neck, threaded rods are drawn parallel to each other, having a self-tapping thread on the proximal end and a metric thread on the distal end, on the distal end of the upper threaded rod with the help of the guide, a temporary stop is installed with rotational movements, made in the form of a bushing with a skewed working part, until a tight contact of the working end of the support is formed with the external cortical plate of the subtrochanteric zone of the femur, and preliminary interfragmental compression is performed in the fracture zone with the help of an impactor, after removal of the impactor and the temporary support on the distal end of the upper threaded rod, using the guide, a permanent support is installed, equipped with a ratchet mechanism and made in the form of a bushing with a skewed working end and a countersunk central hole on the side of the working end, and creating a primary interfragment compression using an impactor, impactor is removed and a spring is sequentially installed on the threaded screw-rod using a conductor and a nut is screwed on until the spring is fully compressed to create a secondary compression, a nut is also screwed on the distal end of the lower threaded screw-rod, after which the upper and lower threaded screws-rods are locked with jam nuts.

EFFECT: invention provides reliable intra-fracture compression in the fracture zone during the operation, reliably stabilizes the femoral neck fracture during the whole period of treatment, promotes fracture consolidation, has low operative injuries.

1 cl, 10 dwg, 3 ex

Description

The invention relates to medicine, namely to traumatology, and is intended for use in the treatment of fractures of the proximal femur.

Fractures of the femoral neck remain a pressing problem in modern traumatology. The reason for this is the high incidence of such injuries, as well as the difficulty of achieving good treatment results. Despite the large arsenal of surgical technologies using various metal structures, necrosis and bone resorption in the fracture zone often occur in the immediate postoperative period, which leads to the disappearance of interfragmentary compression, the formation of a false joint and migration of metal structures. In this regard, a promising direction for solving the problem of treating patients with medial femoral neck fractures is the development of new minimally invasive osteosynthesis methods to improve the results of surgical treatment of this category of patients.

A method of osteosynthesis in case of medial fracture of the femoral neck is known from the state of the art (patent RU2152188, A61B17/56, A61B17/74, published 10.07.2000). The method includes a skin incision, insertion of a pin through the subtrochanteric region into the head of the femur, X-ray control, formation of an opening in the cortical layer of the bone near the pin, insertion of a retainer along the pin into the head of the femur and removal of the pin, wherein first the soft tissues are pierced through the skin incision with a tube with a mandrel fixed in it, then the pin is inserted into the bone fragments through a longitudinal channel in the mandrel and the mandrel is removed, then an opening is formed in the bone through the tube, then the retainer is inserted into the head of the femur along the pin through the tube and the tube is removed.

The disadvantage of this method is its traumatic nature, insufficient stability of fixation and slow growth of bone tissue in the fracture area.

A method for surgical treatment of medial fractures of the femoral neck is known (patent RU 169539, A61B17/56, A61B17/58, A61L27/24, A61L27/12, A61L27/40, published 2001). The method is carried out by means of one-stage reposition, fixation with a pointed three-bladed pin with a through longitudinal channel, through holes on three faces of the pin between its blades and a plug bolt, and introduction of an osteogenic preparation, using a pin having a threaded vestibule at the base with a diameter of 12-13 mm, a depth of 9-10 mm, through holes in the channels with a diameter of 2-3 mm, removed from the tip by 10-12 mm, from which grooves-grooves with a length of 40-60 mm and a depth of 1.5-2 mm pass to the base, and collapan is used as an osteogenic preparation.

The disadvantage of this method is its traumatic nature, significant disruption of blood circulation in the proximal fragment, insufficient stability of fixation, and the impossibility of bringing the fragments together during the process of marginal resorption in the fracture zone.

A method for osteosynthesis of femoral neck fractures and a compression threaded device for its implementation are known (patent RU 2322209, A61B17/56, A61B17/74, A61B17/88, published 20.04.2008). The method is based on the introduction of a compression threaded device under X-ray control along a guide pin previously drawn along the axis of the femoral neck. After repositioning the fragments with a cannulated drill along a guide pin inserted from the subtrochanteric region along the axis of the femoral neck, an opening is made to the depth of the cortical layer, after which a compression threaded device is screwed into the femoral neck along the axis of the guide pin using a removable handle, rotating the compression device clockwise, during which a cylindrical column of bone tissue is cut out with a cutter at the front end of the compression threaded device, which fills the lumen of the channel of the compression threaded device, after which the removable handle and guide pin are removed and the wound is sutured layer by layer.

The disadvantage of this method is the trauma of installing the fixator, significant disruption of blood circulation in the proximal fragment, insufficient rotational stability, high risk of varus deformity, and the impossibility of creating compression in the fracture zone for the entire period of consolidation.

A method of osteosynthesis of femoral neck fractures is known (patent RU 2525739, A61B17/74, published 20.08.2014), in which the fracture is repositioned and, under X-ray control, through the zone located directly under the place of transition of the greater trochanter into the femoral neck at an obtuse angle to the plane of the fracture, open outward and downward, at the maximum distance from the lower point of contact of the bone fragments, a device for fixing femoral neck fractures is introduced, containing a fixing element in the form of a rod with a feather sharpening and three to four turns of self-tapping auger-type thread, a spring, a support cup for the spring with an external thread, a spring retainer and a lock nut for fixing the position of the spring retainer.

The disadvantage of this method is the trauma of installing the fixator, significant damage to the bone tissue of the distal fragment, insufficient rotational stability, and a high risk of varus displacements in unstable fractures.

A method for osteosynthesis of the femoral neck is described, which consists in passing two cerclage loops-ties through the cortical layer of the intertrochanteric line and the head of the femur through formed channels along the anterior and posterior surfaces of the trochanteric region and the head of the femur (patent RU 2749106, A61B17/56, published 04.06.2021).

The disadvantage of this method is the significant trauma to soft tissues on the anterior and posterior surfaces of the hip joint, a high risk of damage to the main vessels and nerves, impaired blood circulation in the fracture area, high blood loss during surgery, the inability to create compression in the fracture area for the entire period of consolidation, and a high risk of varus displacements in the postoperative period.

Also known, selected as a prototype, is a method for treating medial fractures of the femoral neck, including the introduction of a derotation needle through the apex of the greater trochanter and a threaded rod coaxially with the neck into the head of the femur, in which a stop with a working end in the form of three teeth is installed on the distal end of the threaded rod with rotating movements, equipped with a locking (ratchet) mechanism until tight contact of the stop teeth with the outer cortical plate of the subtrochanteric zone of the femur in the plane of the fracture is ensured, then primary interfragmentary compression is performed by screwing the original nut onto the threaded rod, after achieving the necessary tension in the fracture zone, the original nut is unscrewed and sequentially installed on the threaded rod: a washer, a spring and an output nut, wherein the output nut is screwed until the spring is completely compressed, at the end of the operation, the derotation needle is removed from the head of the femur (patent UA 98417, A61B 17/56, A61B 17/74, 2012).

The disadvantage of the prototype is that this method cannot provide rotational stability of fragments and prevent varus displacement due to the use of only one threaded rod. The use of a stop with a working end in the form of three teeth during osteosynthesis has a high risk of perforation of the cortical plate, there is also a risk of soft tissue getting into the gap between the rod and the stop, which increases the risk of diastasis formation between fragments and the formation of a false joint.

The technical problem is to ensure stable fixation of the fragments for the period necessary for fracture consolidation with minimal trauma of the operation.

The technical problem is solved by osteosynthesis of medial fractures of the femoral neck, in which

under X-ray control, two pins are inserted parallel to each other from the subtrochanteric zone into the upper and lower poles of the femoral head coaxially with the femoral neck,

by successively removing the spokes, threaded screw rods with self-tapping threads at the proximal end and metric threads at the distal end are inserted parallel to each other into the formed bone channels according to the length of the femoral neck,

a temporary stop, made in the form of a sleeve with a beveled working part, is installed on the distal end of the upper threaded rod using a conductor with rotational movements until tight contact is formed between the working end of the stop and the outer cortical plate of the subtrochanteric zone of the femur, and preliminary interfragmentary compression is performed in the fracture zone using an impactor,

after removing the impactor and temporary stop, a permanent stop equipped with a ratchet mechanism and made in the form of a sleeve with a beveled working end and a countersunk central hole on the working end side is installed on the distal end of the upper threaded rod using a guide, and primary interfragment compression is created using the impactor,

the impactor is removed and a spring is successively installed on the threaded screw-rod using a conductor and a nut is screwed on until the spring is fully compressed to create secondary compression,

A nut is also screwed onto the distal end of the lower threaded screw rod, after which it is locked with locknuts on the upper and lower threaded screw rods.

The technical result consists in creating reliable interfragment compression in the fracture zone during the entire treatment period with minimal trauma of the operation, which ensures reliable stabilization of the femoral neck fracture. As a result, bone tissues grow together faster, and patients become active in a short time.

The invention is illustrated by figures 1-10, where

Fig. 1 shows the preliminary insertion of two needles from the subtrochanteric zone into the upper

and the lower poles of the femoral head,

in Fig. 2 the introduction of threaded rod screws,

Fig. 3 shows the installation of a temporary stop,

in Fig. 4 installation of a permanent stop, spring and nuts,

Fig. 5 shows a diagram of a threaded screw rod with a stop, spring and nuts,

Fig. 6 shows a photograph of a threaded rod screw with a stop, spring and nuts,

Fig. 7 is a photograph of a permanent stop from the working end with a countersunk

central hole,

Fig. 8-10 X-rays of patients (on the left is an X-ray of a fracture upon admission to hospital, on the right is an X-ray after osteosynthesis).

The method is carried out as follows.

After closed manual repositioning according to Whitman, two spokes 3 are inserted parallel to each other into the upper and lower poles from the subtrochanteric zone under X-ray control into the head 1 of the femur coaxially with the neck of the femur 2 (Fig. 1), which ensures preliminary fixation of the fragments and their rotational stability.

By successively removing the pins 3, two threaded screw rods 4 and 5 are inserted parallel to each other into the formed bone canals in such a way that the section of the upper threaded screw rod 4 with metric thread outside the bone is 2.5 cm, and the section of the lower threaded screw rod 5 with metric thread outside the bone is 1.5 cm (Fig. 2). Insertion of the second threaded screw rod 5 ensures rotational stability of the fracture (on one threaded screw rod there is a risk of angular rotation of the head relative to the distal fragment) and prevention of varus displacements in the postoperative period (the two-support position of the lower threaded screw rod in the distal fragment (Adams arc and external cortical plate) allows to effectively prevent varus displacement of fragments in the postoperative period). A necessary condition for osteosynthesis is the parallel passage of threaded screw-rods (the angle between the rods should not exceed the conventional limit of 5 degrees), otherwise the possibility of a telescopic effect in the process of marginal resorption of bone fragments is hampered (the threaded screw-rods may become a “spacer” between the fragments, which will make it difficult to bring them together).

A temporary stop 6, made in the form of a sleeve with a beveled working part (Fig. 3), is installed on the distal end of the upper threaded screw-rod 4 using a conductor with rotational movements until tight contact with the outer cortical plate of the subtrochanteric zone of the femur is formed, then preliminary interfragmentary compression is performed in the fracture zone using an impactor 7. The role of preliminary compression is to “knock” the fragments together, to squeeze them in such a way as to crush the most protruding trabeculae. In this case, the stronger areas of bone tissue of one fragment press through the more fragile areas of the second fragment, i.e. a new area of contact of the fragments with a minimum gap is created. In young patients, such “shrinkage” of the fracture is insignificant (up to 1 mm), but in older patients with osteoporosis, such “shrinkage” can reach 4-5 mm. In addition, the installation of a temporary stop facilitates the movement, spreading, and “sealing” of soft tissue fragments and periosteum to the cortical plate, which subsequently, when installing a permanent stop, reduces the risk of them getting into the gap between the threaded screw-rod and the permanent stop.

After removing the impactor 7 and the trial stop 6, a permanent stop 8 is installed on the distal end of the upper threaded screw-rod 4 using a guide, equipped with a ratchet mechanism 9 and made in the form of a sleeve with a beveled working end and a countersunk central hole on the side of the working end (see Fig. 4-6), and primary interfragment compression is created using the impactor. Due to the beveled working end, tight contact of the stop 8 with the bone tissue of the outer cortical plate of the subtrochanteric zone of the femur is ensured, which ensures uniform distribution of the mechanical load on the bone tissue, prevents perforation of the cortical plate in the postoperative period and helps maintain reliable interfragment compression. The presence of a countersunk central hole on the beveled end of the stop 8 prevents soft tissue fragments from getting into the gap between the threaded screw-rod 4 and the stop 8 (Fig. 7), which ensures the possibility of unimpeded movement of the stop 8 along the threaded screw-rod 4, since blocking the movement of the stop can lead to the disappearance of interfragment compression and the loss of fixation stability. The ratchet mechanism 9 allows maintaining the primary interfragment compression during implantation at the initial level (Fig. 4), allows for a direct telescopic effect of the stop 8 along the rod 4 as the marginal resorption of bone fragments occurs in the postoperative period and makes the reverse telescopic effect impossible, which prevents the formation of diastasis between the fragments, reliably stabilizes the femoral neck fracture, and enables rapid fusion of bone tissue with minimal trauma of the operation and blood loss.

After creating the primary compression, the impactor is removed and a conductor is installed on the end of the threaded screw-rod 4, along which the spring 10 and nut 11 are successively installed, with the nut 11 being screwed until the spring 10 is fully compressed. The spring 10 ensures the movement of the constant stop 8 along the threaded screw-rod 4 as the marginal resorption of the bone fragments occurs and maintains secondary prolonged interfragment compression throughout the entire consolidation period.

A nut 11 is also screwed onto the distal end of the lower threaded screw-rod 5, after which locking is performed with locknuts 12 on the upper 4 and lower 5 threaded screw-rods, which reduces the risk of loss of secondary compression on the upper threaded screw-rod 4 and proximal migration of the lower threaded screw-rod 5. Then the wound is washed, drained and sutured.

The implementation of the invention is illustrated by the following examples.

Clinical example 1 (Fig. 8)

Patient P., 76, was delivered by ambulance to the Melitopol Regional Hospital, Zaporizhia Oblast, after a traffic accident. He was hit by a car while crossing the street. He was examined and inspected by the traumatologist on duty, and X-rays were taken in direct and axial projections. The X-ray showed a medial fracture of the right femoral neck with displacement of fragments. After a clinical examination and appropriate preparation, the patient underwent surgery using the above-described technique. The wound was sutured and an aseptic dressing was applied.

The wound healed by primary intention and the patient was discharged in a satisfactory condition, no complications were observed. The control radiograph after 6 and 12 months showed consolidation of the fracture. A good functional result and complete social and medical rehabilitation were achieved.

Clinical example 2 (Fig. 9)

Patient P., 86, was delivered by ambulance to the Melitopol Regional Hospital, Zaporizhia Oblast, after a domestic injury, a fall at home. Complaints of pain in the area of the right hip joint. An examination was conducted, an examination by the traumatologist on duty, and radiography was performed in the direct and axial projection. The radiograph shows a medial fracture of the neck of the right femur with displacement of fragments. After a clinical analysis and appropriate preparation, the patient underwent surgery using the above-described method.

The wound healed by primary intention and the patient was discharged in a satisfactory condition, no complications were observed. The control radiograph after 6 and 12 months showed consolidation of the fracture. A good functional result and complete social and medical rehabilitation were achieved.

Clinical example 3 (Fig. 10)

Patient P., 65, was delivered by ambulance to the Melitopol Regional Hospital, Zaporizhia Oblast, after a domestic injury, a fall in the street. Complaints of pain in the area of the right hip joint. Clinically, pain, external rotation, a positive "sticking heel" symptom are noted, axial load causes sharp pain. An examination, examination by the traumatologist on duty, and radiography in direct and axial projections were performed. The radiograph shows a medial fracture of the neck of the right femur with displacement of fragments. After clinical analysis and appropriate preparation, the patient underwent surgery using the above-described technique.

The wound healed by primary intention and the patient was discharged in a satisfactory condition, no complications were observed. The control radiograph after 6 and 12 months showed consolidation of the fracture. A good functional result and complete social and medical rehabilitation were achieved.

Thus, the proposed minimally invasive method of osteosynthesis of medial femoral neck fractures creates reliable interfragmentary compression in the fracture zone during surgery, reliably stabilizes the femoral neck fracture throughout the entire treatment period, promotes fracture consolidation, has low surgical trauma, which as a result allows to reduce the treatment time of patients with medial femoral neck fractures and minimize complications.

Claims (7)

A method of osteosynthesis of medial fractures of the femoral neck, in which under X-ray control, two pins are inserted parallel to each other from the subtrochanteric zone into the upper and lower poles of the femoral head coaxially with the femoral neck, by successively removing the spokes, threaded screw rods with self-tapping threads at the proximal end and metric threads at the distal end are inserted parallel to each other into the formed bone channels according to the length of the femoral neck, a temporary stop, made in the form of a sleeve with a beveled working part, is installed on the distal end of the upper threaded rod using a conductor with rotational movements until tight contact is formed between the working end of the stop and the outer cortical plate of the subtrochanteric zone of the femur, and preliminary interfragmentary compression is performed in the fracture zone using an impactor, after removing the impactor and temporary stop, a permanent stop equipped with a ratchet mechanism and made in the form of a sleeve with a beveled working end and a countersunk central hole on the working end side is installed on the distal end of the upper threaded rod using a guide, and primary interfragment compression is created using the impactor, the impactor is removed and a spring is successively installed on the threaded screw-rod using a conductor and a nut is screwed on until the spring is fully compressed to create secondary compression, A nut is also screwed onto the distal end of the lower threaded screw rod, after which it is locked with locknuts on the upper and lower threaded screw rods.