WO2009140742A1

WO2009140742A1 - Human orthopedic implant plate with double screw holes

Info

Publication number: WO2009140742A1
Application number: PCT/BA2009/000004
Authority: WO
Inventors: Adnan Dizdar
Original assignee: Adnan Dizdar
Priority date: 2008-05-21
Filing date: 2009-05-20
Publication date: 2009-11-26

Abstract

The new type of holes called DSHS/Sa - Double Screw Holes System - Sarajevo is intended for application in human and veterinary osteosynthesis - treatment of bone fractures by means of a stable osteosynthesis. The DSHS/Sa hole in these plates is intended for a new type of the osteosynthesis enabling placement of two screws through a single hole, thus providing for new possibilities in the fracture stabilization (Figures 1, 2, 3, 4A and 5). A scientific process of its employment in the human orthopedics and traumatology will initially start with the use of the dynamic hip implant with a working title - DSHS/Sa R and L (Figures 9 and 10). Later in the process, the DSHS/Sa holes will be applied in other types of plates and will be a part of comprehensive scientific projects (technical drawings shall be a subject of a new approval request). These new holes and adequate screw heads are defined in the technical drawings of the DSHS/Sa holes and screw heads (HDS/Sa - R and HDS/Sa - L), as well as changed shape of the screws. This represents the core of this invention being registered herein (Figures 6, 7 and 8).

Description

HUMAN ORTHOPEDIC IMPLANT PLATE WITH DOUBLE

SCREW HOLES

DSHS/Sa - Double Screw Holes System - Sarajevo

1) TECHNICAL FIELD OF THE INVENTION:

This invention relates to a change in the presently used implantation plates that contain standard holes used in a stabilization of bone fractures classified by the IPC (international patent classification) as A 61 B 17/58. In this way, we will introduce new holes that can be used for placement of two screws instead of one.

2) BRIEF SUMMARY OF THE TECHNICAL BACKGROUND

All types of human orthopedic plates used so far in the practice have offered a possibility of placing only one screw through a single plate opening. Practical work has shown that one screw per plate cannot meet and cannot provide a full-range stability.

3) SITUATION IN THE PRESENT-DAY TECHNOLOGY

The world's leading orthopedic-traumatology school of thought in the segment of internal fixation of human bone fractures is AO International seated in Bern, Switzerland. Its name stands for «Arbeitsgemeinschaft fur Osteosynthesefragen»» - Association for the study of internal fixation. Accomplishments of this association are used as a comparison basis with this invention.

Until 1977, AO International have had plates with only round holes. Starting from 1998, these holes were improved to be oval-shaped holes. Soon after, we have seen an era of compression holes, while 2003 brought along an application of another new type of holes — LCD type holes with combination round holes and angularly stable round holes. The LCP hole provides for these options: a) dynamic and intra-fragmentary compression using the standard screw - placed vertically; b) angularly stable fixation of a screw with threaded sections through the plate positioned vertically, and c) choosing between options a) and b), but using only one screw placed through the plate.

4) ESSENTIAL FEATURES OF THE INVENTION

While observing to all of the principles of a modern osteosynthesis in the use of plates with standard and LCP holes, the plates with new holes offer several advantages. The primary objective behind the application of the new hole with two screws is to improve stability of the broken bone structures (osteosynthesis - fixation of fractured bones). Its secondary objective is to achieve the lowest possible degree of impairment of vascularization of the periost due to reduced number of holes and inserted screws within an even segment of the bone contact area - which is not the case with the standard plates. Another objective of the invention is to reduce a number of screws compared to the quantity used for standard plates. This would be done by relying on our own sense of expected stability between the plate and broken bone structure by selecting adequate types of screws.

An advantage of placing new holes in the proximal femur / thigh-bone is connecting structures that have insofar been impossible to fix using only the plate with standard condylar, angular or DHS plate. Application of new holes in this segment helps us achieve a higher degree of stability of osteosynthesis since we would insert more screws within one smaller segment. This advantage is also evident in reduced level of surgical invasiveness, thus resulting in a smaller incision of the treated area (adhering to the minimum invasive surgery principle).

Further objectives and advantages of the invention are partly shown in a description provided below and shall partly be learned through practical employment of the invention.

Specifics of the application of new holes on these plates requires changing the heads of existing cortical and maleolar screws. This change, as opposed to the standard types of screws, entails reducing the size of screws from the existing 8.0 mm to 6.4-6.5 mm round screw head. The existing stardrive/hexagonal screwdriver shaft remains the same (Figure 6).

The first step in a practical application of the new holes in the human orthopedic implants is designing a new hip dynamic system called HDS / DSHS - Sa (Hip

Dynamic Screw /DSHS - Sarajevo) (Figures 9 and 10).

Afterwards, this new holes type shall be used on a new CP / DSHS Sa (Condylar

Plates DSHS - Sarajevo) and AP / DSHS - Sa (Angular plates DSHS - Sarajevo).

(Technical drawings attached herein).

Furthermore, this new double screw hole shall be applied on flat plates as well.

The new hole, as opposed to the conventional hole types, provides for the following options in insertion of smaller head screws:

A) Vertical placement of a single screw through a round hole (Figure 1);

B) Oblique / vertical placement of a single screw through an oval hole (Figure 2);

C) Vertical parallel placement of two screws through the same hole (Figure 3);

D) Placement of a single vertical screw through a round opening and oblique placement of the other screw through the same hole (Figure 4A);

E) Placement of a single screw through a round opening and oblique placement of the other screw in the opposite direction (Figure 4B);

F) Transverse placement of two screws (Figure 5);

G) Opting for either vertical or oblique screws in order to reduce the number of screws insertion in the osteosynthesis (Figures 1 and 2). 4a) BRIEF DESCRIPTION OF TECHNICAL DRAWINGS

Benefits of the new holes application are substantiated with these technical drawings:

01. DSHS/Sa hole - Round hole with a vertical screw - (Figure 1);

02. DSHS/Sa hole - Oval hole with an oblique-vertical/oblique screw - (Figure 2);

03. DSHS/Sa hole - Two parallel screws - (Figure 3);

04. DSHS/Sa hole - Two screws in a vertical/oblique position (Figure 4A);

05. DSHS/Sa hole - Two screws in a vertical/oblique position (Figure 4B);

06. DSHS/Sa hole - Two screws in a transverse angular position (Figure 5);

07. DSHS/Sa hole — An image of a combination screw (Figure 6);

08. DSHS/Sa hole - type "A" (Figure 7);

09. DSHS/Sa hole - type "B" (Figure 8);

10. HDS/Sa plate - type "R" - right plate with DSHS/Sa holes

11. HDS/Sa plate - type "L" - left plate with DSHS/Sa holes

5. DETAILED DESCRIPTION OF AT LEAST ONE APPLICATION MODULE FOR TfflS INVENTION

A practical implementation aspects and benefits of the DSHS/Sa holes, as opposed to the existing implant holes, are elaborated in the technical drawings provided herein (Figures 1, 2, 3, 4A, 4B, 5 and 6). The comparison of possibilities offered by the new DSHS hole with two screws and by the conventional holes has shown that the structural specifics of the new hole provide for an option of compression and dynamic osteosynthesis using two screws for the plate fixation on the bone. This option was not possible with the standard implant holes.

A combination of a round and oval hole forming a specific shape of the DSHS/Sa hole provides a possibility of insertion of two screws through this single hole, which in turn ensures other, clearly practical options. This hole shape has not been known to the surgical practice in the orthopedic-trauma segment, i.e. in the surgical segment of the ostheosynthesis process. It is for this particular reason that the new DSHS/Sa plate is to be viewed as a novelty in the current ostheosynthesis process.

In order for this new type of holes (DSHS/Sa holes) to enable placement of two screws through the single hole, we have modified the screw heads in a way to reduce the current size of 8.00 mm to 6.4 - 6.5 mm and form a ball-shaped tip of the screw.

This new shape of the screw head prevents collision between screws during their insertion. A sketch of the reduced screw head, as opposed to the standard screw head, is presented in the attached technical drawings (Figure 6).

This modified screw head required creating a new DSHS/Sa hole with a ball-shaped mill.

The head and the type of this new opening had to be adequate in measure to the type and quality of the new hole (Figure 6). 6a) BENEFITS OF THE DSHS/Sa HOLE

- The DSHS/Sa hole enabling fixation of one screw vertically, while the other is inserted angularly through the same hole, provides for a so called divergent/angular stability of the fixation between the plate and the bone.

It is for this reason that the DSHS/Sa plate is technically safer and stronger in terms of stability, which is unlike the types currently applied in the ostheosynthesis.

- Placement of a divergent screw through a single hole captures a length of the bone marrow that equals a diameter of 2.5 to 3 holes in the standard plates. Because of this, a number of the new DSHS/Sa holes in the new plates will be much lower.

- The DSHS/Sa hole also provides for a higher rate of stability than the holes applied so far in the ostheosynthesis. This is because of the two screws placed in divergent manner and because of the reduced number of screws used in the plate-to-the-bone fixation since we can now choose between six ways of placing the screws depending on the fracture type and on a personal experience of a surgeon.

- The DSHS/Sa hole also reduces the damage rate of bone structures due to the reduced rate of drilling and burning involved in these structures.

Furthermore, this lower degree of drilling through the bone reduces damages to periostal and endostal blood supply to the bone, as well as preserves blood vessels carrying nutrients to bones.

- It is very important to note that a combination of parallel and divergent screws in a metaphysis of long bones increases the stability of softer segments of bones. This is surely of a special significance.

- Possibilities that the DSHS/Sa holes are offering in regions wider than the plates themselves relate mostly to the hip and knee regions, especially if applied in oblique positions to the plate. In this way, the plate would capture those bone parts that were not inaccessible through the conventional holes. For example, in a trochanteric hip region - we can achieve even better stability of a broken small trochanter or even additional stability of the lower part of the neck of the thigh bone (femur).

- Applying the new DSHS/Sa hole in the implants creates preconditions for a size and length reduction of the implant, which in turn results in a smaller incision. This principle directly relates to the adherence to the minimum invasive surgery technique.

- Better stability in the ostheosynthesis (an implant to the bone fixation) provides an incentive for a better healing of the fracture and therefore reduced failure rate in the surgical practice. 7) INVENTION EMPLOYMENT METHOD

The invention of the DSHS/Sa holes and their application in the implants enable practical, useful and permanent change in a large number of human orthopedic implants.

AU types of implants applying the DSHS/Sa holes can be developed in the regular course of the implants manufacturing.

The inventor has decided for this new DSHS/Sa hole to be initially applied in a new design of the dynamic plate intended for fractures of a proximal femur region. The invention's working title is HDS/Sa - Hip Dynamic Screw / Sarajevo.

Attached technical drawings of the HDS/Sa - R and HDS/Sa - L clearly indicate to a difference between the conventional DHS plate and HDS/Sa plate following the AO International school of thought.

This difference is reflected in a use of the new DSHS/Sa hole. Also, the standard DHS plate that is two-sided, has not modified into two new plates - left (L) and right (R) plates.

Besides, new DSHS/Sa holes have a specific positioning in relation to the DHS plates.

The technical drawings of the HDS/Sa - R and HDS/Sa - L are attached herein (Figures

9 and 10).

The practical employment of these new HDS/Sa plates in surgery shall point out to their specifics and benefits compared to the standard type of the DHS plate.

In the later stage, the new DHS/Sa plates will also be applied to other plate types intended for the human orthopedic implants. Technical drawings will be provided in additional attachments of the invention application for the DSHS/Sa holes.

A process of scientific comparison will prove the quality and benefits of the new plate type.

Signature or stamp of the invention applicant

Claims

PATENT REQUEST

1. The human orthopedic plate for the osteosynthesis with openings for screws is specific in a sense that these holes are designed in a way that the single slot can be used for insertion of two screws.

2. The human orthopedic plate hole is specific in a sense that it represents a combination of a round and an oval hole, which enables placement of two screws through the same hole.

3. As per the item 2. the hole is specific in a sense that it is ball-shaped and fits the ball-shaped form of the screw head.

4. Screws designed for the human orthopedic plate insertion are specific in a sense that the screw head is ball-shaped (Figure 6), which enables placement of two screws through a singe hole.

Adnan Dizdar