JP6429858B2 - Method for determining the index of bone implant stability - Google Patents

Description

The present invention relates to bone implantation, and in particular, to a method for determining an index of bone implant stability. In this specification, “bone implant” may be simply referred to as “implant”.

  A number of bone sites are used as receiving sites for implant implantation and loading. In dentistry, these parts are mainly composed of the mandible and the upper or lower maxilla. In orthopedics, the limbs of the femur (femur), humerus or tibia (tibial) are considered. These bones are composed of two bone tissues. High density cortical bone forms a hard outer layer of bone organs. Reticulated, trabecular or cancellous bone has a high surface area but is not very dense, not flexible, weak and low in hardness. Usually occurs at the end of the long bone, near the joint. Its main anatomical and functional unit is the bone trabeculae. The ability of these bones to successfully receive implants depends not only on patient characteristics, surgical techniques and implant design, but also on bone quality and density, and the structural organization and microstructure of the cancellous bone portion. Sufficient rehabilitation opportunities are based on the initial stability of the implant placement and the good biological and biomechanical capabilities of the implant.

  Implant stability is achieved at two levels: That is, primary stability, which is mechanical stability obtained immediately after transplantation, and secondary stability obtained along the bone bonding process. Certain primary stability is a good indicator and a prerequisite for secondary stability. The ability to accurately assess not only secondary stability, but also this primary stability, makes it possible to design an appropriate surgical protocol and its follow-up.

  A major challenge is to develop methodological means that can understand the key factors that contribute to the performance of the implant, particularly with respect to the primary stability of the implant.

  Implant primary stability refers to the stability of an implant, eg, a dental implant immediately after implantation. The value is typically derived from mechanical engraving of a titanium screw implant in the patient's bone tissue. High initial stability can be an indicator of immediate loading during prosthetic reconstruction.

  The primary stability value of the implant gradually decreases with the reconstruction of the bone tissue around the implant in the first weeks after surgery and moves to secondary stability. Its properties are quite different from the initial stability because it is the result of a continuous process of osteosynthesis. When the treatment process is complete, the initial mechanical stability is completely replaced by biological stability. The most dangerous time for a successful transplant is the time of minimal initial stabilization, withholding sufficient bone reconstruction to support long-term maintenance of the implant. This usually occurs 3-4 weeks after transplantation. If the primary stability is not high enough after implantation, the mobility of the implant is high and causes failure.

  Resonant vibration frequency analysis (using an RFA-Osstel ™ device) and damping capability assessment (Periotest ™ technology) are non-destructive oral test methods for assessing the stability of implants after implantation. . In early Periodotest techniques, an electronic control rod typically strikes the implant several times per second at a constant rate. The rod is decelerated when it contacts the implant, and its frequency changes. If the implant is stable, the deceleration is high, which is a dampening effect of the tissue surrounding the implant. After hitting the implant, the rod moves back. A fast reversal indicates a high damping effect. The Periotest ™ technology is intended to provide an implant of interest that is used to assess the stability value of the implant-bone interface. Resonance frequency analysis (RFA) is a non-invasive and non-destructive quantitative measure of implant bonding by assessing changes in implant stability over time. This technique consists of using an adapter placed on a screw attached to the implant. The probe then emits magnetic pulses at various frequencies that cause the screw to vibrate. The adapter begins to vibrate and the probe hears the tone and converts it to a resonant frequency (RF), which corresponds to an ISQ (implant stability index) value. The higher the frequency, the more stable the implant. ISQ is used as a measure of the stability of dental implants and the level of bone bonding. The ISQ scale is typically 1-100, with ISQ of 55-85 being acceptable stability. In recent wireless versions, RFA uses a magnetic peg—the so-called Smart peg—connected to an implant or an abutment. The pegs are excited and RF is expressed electromagnetically as ISQ units.

  Although Periotest and RFA technologies have great promise in dentistry and contribute to the adaptation and improvement of implant technology, they have several drawbacks. The exact correlation between RFA values and bone density or cortical thickness has not yet been clearly established. The Periotest technique shows variations between operators and between devices. These techniques do not use or provide images of acceptor sites. Most importantly, both techniques allow assessment of implant stability only after implant insertion or loading, thus limiting post-operative indications in the case of inadequate stability, and for transplanted bones. Prolonged surgery time causes patient discomfort. They allow the surgeon to confirm the binding of the implant, but do not provide valid and reliable data for predicting the stability of the implanted implant. Such opportunities are not available to orthopedic surgeons.

  Implantology professionals actually use experience-based protocols and averages resulting from their expertise to design ad hoc implant and transplant surgery protocols. These values fit most surgical situations, but the implants are at high risk of failure, cause severe pain, cannot provide solutions for out-of-range patients and clinical situations, and are necessarily complex. In many cases, this leads to a surgical procedure that is temporarily relieved. Instead, an objective and accurate measurement of predicted implant stability allows the surgeon to implant the implant on a case-by-case basis so that the patient can enjoy the benefits of a personalized protocol with a high probability of success. You will be able to make informed decisions about protocol selection.

  Non-Patent Document 1 describes the relationship between bone mineral density (BMD) before implant placement, measurement of implant stability at implant placement, and bone loss around the immediate implant after one year in situ. is investigating. This method uses a computed tomography examination as a preoperative method for evaluating the density of the jawbone before implant placement. However, after one year, there was no difference in changes in marginal bone density between implants placed on survival or different density bone tissue. This can explain that bone mass or density is not a useful parameter for determining implant stability.

  Non-Patent Document 2 ("JPIS paper") discusses the stability assessment of dental implants using fractal analysis to assess bone density. The purpose of this study is to investigate whether the fractal dimension from panoramic radiographs as represented by RFA is related to the primary stability of the implant. The authors found a statistically significant linear correlation between the panoramic X-ray image and the fractal dimension calculated from the RFA ISQ values. The authors conclude that the fractal dimension of the bone may be a useful way to present a general preoperative treatment plan.

US Patent Application Publication No. 2008 / 0031412A1 US Patent Application Publication No. 1010 / 09998212A1 US Patent Application Publication No. 2011 / 0036360A1 US Pat. No. 7,609,867 French Application Publication No. 2960762A1

Bergkvist G, Koh KJ, Sahlholm S, Klintstrom E, Lindh C. et al. , “Bone density at impulse sites and its relationships to assessment of bone quality and treatment outcome”, Int J Oral Maxilof Implants. 2010 Mar-Apr; 25 (2): 321-8 Dae-Hyun Lee et al, “A clinical study of alveolar bone quality used in the first 10 minutes of the first 10 minutes, and the first 20 minutes of the first 10 minutes. 2010

The cited JPIS article is limited to panoramic X-ray images in which the fractal dimension is calculated and compared to the implant stability index ( ISQ ). The fractal dimension is intended to be the only predictor of primary stability. However, panoramic X-ray images are known to be very distorted images, and therefore may not be effective in measuring parameters such as fractal dimensions that are only relevant to scale-invariant spatial properties. The panoramic image has no scale invariant spatial characteristics.

  According to a main aspect of the present invention, a method for determining an index of bone implant stability is provided. The method includes providing a two-dimensional or three-dimensional image of a bone at a position where a bone implant is scheduled: determining a bone structural parameter at the position from the two-dimensional or three-dimensional image: the bone Providing implant stability data associated with data representing the structural parameters of the bone: and from the structural parameters of the bone and the implant stability data, an indication of the stability of the planned bone implant after implantation at the location Determining.

  The present invention applies to any kind of two-dimensional or three-dimensional X-ray scanning, except for panoramic images, because the level of distortion that appears in the panoramic image prevents it from being used.

  The bone implant can be selected from the group consisting of a dental implant and an orthopedic implant. Further, the bone implant may include a biomaterial such as a bone substitute, and in this case, the present invention provides a method for determining an indicator of its bone attachment. Often, bone implants contain screws of inert material, especially titanium.

  The method includes determining an index of bone implant stability as primary stability, which is the stability of the implant on the day of implantation of the implant in the bone, and / or after treatment and / or bone of the implant It may include determining an indication of bone implant stability as secondary stability, which is stability after bonding.

  Thus, unlike the JPIS article, which is only suitable for assessing primary stability, the method of the present invention is suitable for predicting both primary and secondary stability.

If a three-dimensional image of bone is provided at the location where the bone plant is planned, the three-dimensional image is processed as a two-dimensional image to determine the bone structural parameters to determine the bone structural parameters. Projected onto a plane to be processed or processed as a three-dimensional image.

  In this method, the implant stability data can be evaluated by resonance frequency analysis or by evaluating the damping capacity of a reference implant. Implant stability can also be assessed by resonance frequency analysis, for example, either immediately after implantation or after an osteosynthesis period.

  The bone structure / tissue parameters used in the present invention are not measurements of the fractal dimension and cannot be compared to the fractal dimension in an image-like type. Calculated from experimental variograms of gray levels in the image. In the JPIS paper, the fractal dimension is performed using a tile counting method from skeletal images, which is very different from the experimental variogram measurements performed from images containing trabeculae used in the present invention. Is.

  In the present invention, bone tissue parameters are calculated directly at the gray levels contained in the X-ray image, and local variations in pixel intensity are determined to be almost final estimates. In contrast, in the cited JPIS paper, the fractal dimension is calculated from a skeletonized binary image in which no information remains in the local contrast.

  Both the cited invention and the cited JPIS article refer to RFA because RFA is the ultimate criterion for assessing the stability of an object inserted into a material. Nevertheless, in the cited paper, RFA is only used as a comparison, but in the present invention, RFA values are incorporated into the process and used to define the optimal shape of bone tissue parameters. Yes.

  Although the cited paper focuses only on primary stability, the present invention provides an assessment of the primary or secondary stability of the implant.

  The cited JPIS paper shows a very low or even unimportant relationship between RFA and the fractal dimension, which shows that the described method provides a strong predictor of implant primary stability. It is not appropriate to get.

  In one embodiment, the evaluation of implant data includes a biomechanical test such as measuring the pullout strength of the implant.

  In other embodiments, the evaluation of the implant data includes a biological analysis of the bone connectivity of the implant.

  Other aspects of the invention include assessment of bone structural parameters before surgery as a predictive material for implants and post surgery to monitor bone attachment.

The tissue analysis that determines the structural parameters of the bone is the analysis of trabecular tissue.

  The bone structural parameters are advantageously determined by tissue analysis of a two-dimensional or three-dimensional grayscale image in the region of interest at the location where the bone implant is scheduled.

In a preferred embodiment, the computing device determines bone structural parameters by performing a series of the following steps to process a digitized two-dimensional or three-dimensional image. a) searching for the gray level h (O) of each pixel of the 2D or 3D image in the region of interest of the 2D or 3D image; b) surrounding the pixel for which the gray level h (O) was searched Selecting a set of pixels at distance r; c) searching for a gray level h (r) of said set of pixels; d) formula: V (r) = [ h (r) −h (O) ] ² E) calculating a function V (r) representing a difference between the gray level h (r) and the gray level h (O); e) a horizontal axis as the distance r and a vertical axis as the function V. Tracing a curve associated with V (r) obtained on a logarithmic scale as (r); and f) determining a slope of the curve as a structural parameter α of the bone.
The present invention relates to bone implantation, and in particular, to a method for determining an index of bone implant stability. In this specification, “bone implant” may be simply referred to as “implant”.

The invention will now be described by way of example with reference to the accompanying drawings in which:
FIG. 3 is a cross-sectional view of a dental implant inserted into a jawbone. FIG. 3 is a cross-sectional view of an orthopedic implant inserted into a knee bone. FIG. 3 is a view of a portion of a reference bone sample used after placement of an implant. FIG. 6 is an X-ray image of a bone sample covered by an extracted region of interest where an implant is to be placed. FIG. 6 is an X-ray image of a patient's mandible covered by an extracted region of interest where an implant is to be placed. It is a graph of the maximum correlation of an implant stability index and a bone tissue parameter. FIG. 5 is a table 1 showing bone tissue parameters for each configuration and calculated ISQ values for each implant (or corresponding relevant region on the jawbone). It is a table | surface and is Table 2 which shows the bone tissue parameter with respect to each structure, and the correlation coefficient of ISQ. It is an X-ray image of a patient's spine showing an extracted region of interest where the implant is to be placed.

  The present invention relates to a method for determining an indication of the quality of a bone site intended to receive an implant, which is used as a predictor of the stability of an implant that is screwed or adhered thereto. A preferred embodiment of the method of the present invention is characterized by the use of receptor bone site imaging techniques, and the gray level space of the scanned image of the receptor bone site before loading and screwing / adhering the implant. Quantitative analysis of global variation can be used. By using specialized software, the spatial variation of these gray shades can be directly correlated with bone tissue, which is a strong predictor of implant osteosynthesis. The output of the analysis method shows a digitized optical measurement variogram of gray shades in the image so that the stability indicator of a particular receptor bone region is evaluated by the average value of this region's indicator. It is constituted by. For each pixel in the image of the receptor site, the variation of the surrounding pixels can be calculated as the sum of the squared differences in gray shade intensity at a given distance of the reference pixel. These variations are then plotted using a log scale. Using a one-to-one mathematical function, a pixel area that can be computerized is defined, and a measure of stability is calculated as the slope of this function.

Imaging Technique Initially, a 2D or 3D image of the bone is provided at the location where the implant is planned.

  The images referred to herein are made using, for example, X-ray imaging techniques, particularly digital radiography, two-photon absorption imaging, standard scanners, and cone beam scanners.

As described, when a 3D image of bone is provided at a location where a bone implant is planned, the 3D image is on a plane to be processed as a 2D image to determine bone structural parameters. Projected or processed as a three-dimensional image to determine bone structural parameters.

  Providing a two-dimensional or three-dimensional X-ray image of bone for the prognosis of bone structure is described in Patent Documents 1 to 3, for example.

  Digital x-ray imaging uses direct or indirect techniques, and both techniques can be used in numerical x-ray imaging.

Bone structure parameters According to the method of the present invention, the bone structure parameters at the location where the implant is planned are derived from two-dimensional or three-dimensional images. As the bone structural parameter, for example, trabecular tissue is used for the tissue analysis . The bone structural parameters can be determined, for example, by tissue analysis of a 2D or 3D grayscale image of a 2D image within the region of interest at the location where the bone implant is scheduled.

  Gray shades are defined as different luminance steps depending on the amount defined in the image. The minimum difference between the two shades of gray corresponds to the image quantification process. The contrast ratio is defined as the maximum luminance value divided by the minimum luminance value when the dynamic range is the number of shades of gray between the minimum and maximum values.

A preferred method for obtaining bone structural parameters is described in US Pat. No. 6,057,086, which is summarized in that the computing device performs the following steps to process a digitized two-dimensional or three-dimensional image.
a) retrieving the gray level h (O) of each pixel of the 2D or 3D image in the region of interest of the 2D or 3D image;
b) selecting a set of pixels at a distance r around the pixels for which the gray level h (O) was retrieved;
c) retrieving the gray level h (r) of the set of pixels;
d) A function V (r) representing the difference between the gray level h (r) and the gray level h (O) using the formula: V (r) = [ h (r) −h (O) ] ^2. Calculating step;
e) following a curve associated with V (r) obtained on a logarithmic scale with the horizontal axis as the distance r and the vertical axis as the function V (r); and f) the slope of the curve. Determining the bone structure parameter α.

  In steps a) to f), numerous technical choices can be made for the calculation, and the bone structural parameters will change. Part of the method of the invention consists of adjusting these choices to maximize the correlation between bone structural parameters and implant stability.

  Another method for obtaining the bone structural parameters disclosed in US Pat. No. 6,053,836 selects a region of interest in a gray level image of bone tissue, calculates a gray level, and compares this with a limit value. Is based on that. The value of the light emission parameter is determined according to the gray level and the threshold value. The image is obtained using an imaging device with a new value of the radiation parameter.

Implant Stability Data The method of the present invention includes providing implant stability data associated with data indicative of bone structural parameters.

  Implant stability data is collected using bone samples (in vitro from human cadaver or in vivo from patient bone) and a series of reference implants. A reference implant is implanted in the bone sample and the stability of the implant is assessed using an implant stability meter that calculates the RFA of all implanted implants. Implant stability is recorded immediately after implantation (primary stability) and / or after the period of bone attachment (secondary stability, in vivo bone only).

  A two-dimensional or three-dimensional image of the bone sample is acquired and bone structural parameters are calculated from the image using various variables.

  Implant stability data is used to select appropriate variables. The selected variable maximizes the correlation between bone structural parameters and RFA. Several sets of variables are defined, one uses primary stability data to optimize bone structural parameters as an index of primary stability of the implant, and the other uses the secondary stability of the implant. Secondary stability data is used to optimize bone structural parameters as indicators. A set of additional variables to optimize bone structural parameters as an indicator of implant stability in different types of bones: mandible, maxilla, hip, femur, knee joint, tibia, shoulder, etc. Can be used. Additional sets of variables include: various types of implants: dental implants having various forms; orthopedic implants that may be pins, bars, screws or plates; substitute bones (in this case, bone structural parameters Can be used to optimize bone structure parameters as an indicator of implant stability).

Determination of an indication of the stability of the planned bone implant The method of the present invention is based on the determined bone structural parameters and from the implant stability data of the planned bone implant after implantation at the location. Provides for determining stability indicators.

  Acquire a 2D or 3D image of the bone intended to receive one or more implants. Bone structural parameters are calculated from the image using variables optimized for the determination of primary stability (and conversely secondary stability).

Example 1 Dental Implant FIG. 1 shows, by way of example, a cutaway view of a dental implant 1.18 inserted into a jawbone 1.16. The jawbone 1.16 is composed of cortical bone and trabecular bone. The quality of the trabecular bone is an important determinant of good bone bonding of the implant. As shown, the tooth has a crown 1.10 over a root 1.12 that extends through the gingiva 1.14 and into the lower jawbone 1.16. The teeth incorporate an implant 1.18 in the form of a screw made of an inert material, preferably titanium.

  Before loading the implant, an X-ray image of the area of the jawbone where the implant 1.18 is scheduled is taken. This X-ray image is analyzed to determine bone structural parameters representing trabecular tissue by tissue analysis of a 2D or 3D gray level image of the region of interest at the location where the bone implant is scheduled. . Bone structure parameters are designed to assess trabecular quality. Preferably, this analysis is performed using the method described in US Pat. This bone structural parameter is compared to a series of predetermined values from a series of reference implants, as described above in “Implant Stability Data” and also from equivalent types of bone, ie, mandible or maxilla. The selected variable is also used for comparison.

The resulting calculation yields a value that predicts whether the scheduled implant is stable for primary and secondary stability. If the results indicate that the implant should be stable, the dentist can perform the implant and reduce the delay before loading. If the results indicate that the implant is unstable, the dentist can take any necessary action.

  After transplantation, primary and secondary stability can be confirmed by RFA measurement and compared with predicted values.

Example 2 Orthopedic Implant FIG. 2 shows by way of example an X-ray diagram of an orthopedic knee implant 2.12 inserted into a femur (femur) 2.16 and a tibia (tibial) 2.18. . The femur 2.16 and the tibia 2.18 are composed of cortical bone and trabecular bone. Trabecular quality is an important determinant for a successful osteosynthesis of the implant. As shown, the implant is inserted into the femur and tibia, primarily at their trabecular site. This is because they are the bone-implant contact surfaces within the trabecular bone (bones with fast remodeling speed), which is an important determinant of good osteosynthesis.

  Prior to loading the implant, an X-ray image of the area of the knee where the implant 2.12 is scheduled is taken. This X-ray image is analyzed to determine bone structural parameters representing trabecular tissue by tissue analysis of a 2D or 3D gray level image of the region of interest at the location where the bone implant is scheduled. . Bone structure parameters are designed to assess trabecular quality. Preferably, this analysis is performed using the method described in US Pat. This bone structural parameter is compared to a series of predetermined values from a series of reference implants, as described above in “Implant Stability Data”, and selected variables from an equivalent type of bone, ie, knee. Also compared using.

  The resulting calculation yields a value that predicts whether the scheduled implant is stable for primary and secondary stability. If the results indicate that the implant should be stable, the orthopedic surgeon can perform the implant and reduce the delay before functional recovery. If the results indicate that the implant is unstable, the orthopedic surgeon can take any necessary action.

Example 3 Primary Stability of Dental Implants in the Posterior Mandible Using a complete bone sample 3.1A (FIG. 3.1) without teeth, ie the mandible, the location is where the implant is placed, Define the posterior part of the lower jaw. A standard imaging protocol is used to take an image of the bone sample, eg, an X-ray image around the apex of the root (FIG. 3.2). For each of the resulting images, one or several of the 3.2A regions of interest are drawn on the bone where the implant will be placed ( Figure 3.1 ). Thereafter, the tissue analysis is preferably performed using the method described in Patent Document 4. For each region of interest, the bone structural parameters are calculated using several arrangements C ₁ (Table 1, FIG. 3.5).

Using the same set of bone samples, a reference dental implant is placed in the previously defined location 3.1B (FIG. 3.1). Implant stability is measured using reference frequency analysis with a reference Osstel device to determine the implant stability index (ISQ) ( Table 1 , Figure 3.5).

  For each region of interest and for each configuration of tissue analysis, the correlation of ISQ and bone structural parameters is determined (Table 2, Figure 3.6).

Finally, the maximum correlation C ₁ is determined ( FIG. 3.4 and Table 2, FIG. 3.6) and the corresponding structure of the tissue analysis is stored. This correlation C ₁ is specific for assessing the primary stability of dental implants in the posterior mandibular region using this type of medical imaging device.

Using an x-ray image of the bone of the patient where the implant is scheduled, i.e., the posterior part of the mandible (Fig. 3.3), the region of interest 3.3A is drawn on the bone where the implant is planned. Histological analysis is calculated by using configuration C _1. The value obtained makes it possible to predict whether the planned implant is stable immediately after installation (primary stability). If the results indicate that the implant should be stable, the dentist can perform the implant and, for example, reduce the delay before loading. If the results indicate that the implant is unstable, the dentist can take any necessary action.

Example 4-Primary stability of orthopedic implants in the spine.
A set of bone samples, such as a spine sample, is used to take a plain X-ray image of the spine using standard imaging protocols (FIG. 4). For each of the resulting images, one or several of the 4A regions of interest are drawn on the bone where the implant will be placed. Thereafter, the tissue analysis is preferably performed using the method described in Patent Document 4. For each region of interest, the bone structure parameters are calculated using several configurations C _i .

  Using the same set of bone samples, the spinal implant is placed in a previously defined location. The stability of the implant is then measured by measuring the force required to pull the implant from the bone sample. For each region of interest and each configuration of the tissue analysis, the correlation of pullout strength and bone structure parameters is determined.

Finally, determine the maximum correlation and store the corresponding structure of the organizational analysis. This configuration C _a is specific for evaluating the primary stability of this type of spinal implant using this type of medical imaging device.

Using a simple X-ray image of the patient's spine where the implant is planned, the region of interest 4A is drawn on the bone image where the implant will be placed. Tissue analysis is calculated using configuration C _a . With the values obtained, it is possible to predict whether the planned implant is stable immediately after installation (primary stability).

Claims (9)

A calculation device for determining an indication of the stability of a planned bone implant after implantation of the bone implant before transplanting the planned bone implant into bone;
(i) providing a two-dimensional or three-dimensional image of the bone at which the bone implant is scheduled;
(ii) determining a bone structural parameter at the position from the two-dimensional or three-dimensional image;
(iii) providing bone implant stability data associated with data representing the structural parameters of the bone;
(iv) determining, from the determined bone structural parameters and the bone implant stability data, an indicator for the stability of the planned bone implant after implantation at the location;
Is executed by the computing device,
The structural parameters of the bone in the step (ii) are determined by tissue analysis of a two-dimensional or three-dimensional grayscale image in a region of interest at a position where the bone implant is planned, and the tissue analysis is In order to analyze the spatial variation of the level, it is carried out directly at the grayscale level contained in the 2D or 3D image,
Assessing the bone implant stability data of step (iii) by at least one of a biomechanical test including a resonance frequency analysis of a reference implant, a dampening ability of the reference implant, or a measurement of the pullout strength of the reference implant;
In the step of determining the index (iv), an index of stability of a bone implant scheduled as primary stability is determined, and the primary stability is a bone implant on the day when the bone implant is implanted in the bone. Is the predicted stability of the method.   The method of claim 1, wherein the bone implant is a dental implant or an orthopedic implant.   The method according to claim 1 or 2, wherein the bone implant comprises a bone substitute or other biomaterial.   4. The method of claim 1, 2 or 3, wherein the bone implant comprises a screw of inert material.   Said calculating device determining an indication of the stability of the bone implant as a secondary stability, which is the stability from the start of the healing of the bone implant to the end of the healing and / or after osteosynthesis of the bone implant. The method of any one of Claims 1-4 containing.   The computing device provides a three-dimensional image of the bone at the location where the bone implant is scheduled and projects the three-dimensional image onto a plane that is processed as a two-dimensional image to determine bone structural parameters. The method according to claim 1, wherein the method is processed as a three-dimensional image.   The method according to any one of the preceding claims, wherein the computing device determines the structural parameters of the bone before surgery as a prediction of bone implant stability and after surgery to monitor implant bonding. .   The method according to any one of claims 1 to 7, wherein the tissue analysis for determining the structural parameter of the bone is an analysis of trabecular tissue. 9. The method according to any one of claims 1 to 8, wherein the computing device processes the digitized two-dimensional or three-dimensional image of the bone structural parameter [alpha]. ) To step f) are performed in a continuous manner and determined.
a) retrieving the gray level h (O) of each pixel of the 2D or 3D image in the region of interest of the 2D or 3D image;
b) selecting a set of pixels at a distance r around the pixels for which the gray level h (O) was retrieved;
c) retrieving the gray level h (r) of the set of pixels;
d) A function V (r) representing the difference between the gray level h (r) and the gray level h (O) using the formula: V (r) = [ h (r) −h (O) ] ^2. Calculating step;
e) following a curve associated with V (r) obtained on a logarithmic scale with the horizontal axis as the distance r and the vertical axis as the function V (r); and f) the slope of the curve. Determining the bone structure parameter α.

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