RU2371093C1 - Osteoporosis diagnostic technique in non-union - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly to traumatology and orthopaedics and can be used for osteoporosis diagnostics in surgical service of non-union fractures and false joints of limb bones. It involves comparative X-ray imaging of a damaged and healthy contralateral bone segment on the same film in frontal projection with adjacent joints. In symmetric sites, out of the damage zone, thickness of cortical plates on both limbs equally spaced from joints and diametre of diaphysis at this level are evaluated. Nordine-Burnett's cortical index is calculated by formula:

where CI is cortical index, CD and XY is thickness of cortical layer, AB is diametre of diaphysis. The difference of cortical indices of damaged and healthy contralateral bone segment (ΔCI) is determined, and if said difference of cortical indices of damaged and healthy limbs is 15% or more, than osteoporosis is diagnosed. If 10%<ΔCI<15%, osteopenia or mild osteoporosis with T-criterion -2.5 to -2.7 SD. If the difference of cortical indices is 10% or less, or the difference of cortical indices is not observed, the absence of osteoporosis is diagnosed for the given patient.

EFFECT: method provides simple and qualitative diagnostics of osteoporosis and allows diagnosing mild osteoporosis and osteopenia.

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Description

The invention relates to traumatology and orthopedics, in particular to the diagnosis of osteoporosis in case of overgrown fractures and false joints of limb bones and can be used in clinical practice.

In the vast majority of cases (90.4%), non-joint of the leg and thigh bones is accompanied by post-traumatic immobilization osteoporosis (Assessment of the mineral density of bone tissue in pseudarthrosis and non-healing bone fractures of the lower extremities / S.V. Gyulnazarova, O.A. Kuznetsova // Orthopedics genius - 2002. - No. 1, p. 161-162).

Known methods for the diagnosis of osteoporosis, based on the determination of bone mineral density: photon absorptiometry, monoenergetic and dual-energy x-ray absorptiometry, quantitative computed tomography and others (J. Franke, G. Runge. "Osteoporosis". M: Medicine, 1995, p. 117 ; Rozhinskaya L.Ya. Systemic osteoporosis. M., Publisher Mokeev, 2000, p. 75-82). However, due to the high cost of equipment, these methods are not widely available to most doctors, as are laboratory diagnostics of osteoporosis. Dual energy X-ray densitometry, recognized as the "gold standard" in the diagnosis of osteoporosis, is not used enough due to the small number of bone densitometers in the Russian Federation.

Standard radiography allows you to identify both osteoporosis and its complications (fractures), and to conduct differential diagnosis of osteoporosis with various pathological conditions, accompanied by a decrease in the content of minerals in bone tissue (N.M. Mylov. Radiological diagnosis of osteoporosis // "Osteoporosis and Ostesteopathy" ", 1998, No. 3, pp. 7-8). However, it is known that x-ray diagnosis of osteoporosis is possible only with pronounced bone loss - at least 25-30% (Rozhinskaya L.Ya. Systemic osteoporosis. M: Publisher Mokeev, 2000, p. 67).

A known method for the diagnosis of osteoporosis by evaluating radiographs of various skeleton bones, for example, by the Nordin-Barnett index (Barnett E., Nordin B. // The radiological diagnosis of osteoporosis: A new approach. // Clin. Radiol. V.ll, P.166 -174, 1960). To assess osteoporosis from the femur, on the X-ray of the thigh approximately 10 cm below the trochanter, the total thickness of the medial and lateral cortical layers is determined and divided by the size of the transverse diameter of the thigh, the obtained value is multiplied by 100. With a CI value of less than 46%, osteoporosis is diagnosed (E. P. Podrushnyak. “Osteoporosis - a problem of the century”, Simferopol, “Odyssey”, 1997, p.127-128). According to a similar scheme, it is proposed to calculate the tibia index, if the index is less than 40, osteoporosis is diagnosed (V.O. Marx. Orthopedic Diagnostics. Minsk, Science and Technology Publishing House, 1978, p. 505).

With its simplicity and lightness, this method works clearly only with pronounced degrees of osteoporosis. Due to its low sensitivity, the method is not suitable for diagnosing the early stages of osteoporosis, and due to slight and slow fluctuations (inertness) of changes in the thickness of the cortical bone layer, it is only suitable for assessing the dynamics of osteoporosis over a long observation period of at least a year. This method was proposed for the diagnosis of senile and postmenopausal osteoporosis, as well as for the detection of secondary osteoporosis in patients suffering from systemic diseases (rheumatoid arthritis, systemic lupus erythematosus, diabetes mellitus, etc.). In the available literature, no information was found on the use of the cortical index in trauma patients.

The task - to simply and accurately diagnose osteoporosis in patients with bone nonunion of one of the lower extremities is solved as follows.

In the method for the diagnosis of osteoporosis, including the measurement by X-ray of the value of the diameter of the tubular bone, the total width of both cortical plates and the subsequent calculation of the cortical index according to the formula, according to the invention, the measurements are carried out in the symmetric zones of the affected and healthy bone segments with subsequent calculation of the cortical indices for each of them. If the difference between the values of the cortical index of the affected and healthy limbs is equal to or more than 15%, osteoporosis with a value of T criterion of at least -2.7 SD is diagnosed. When the difference in cortical index values is more than 10%, but less than 15%, osteopenia or mild osteoporosis with a T criterion from -2.5 to -2.7 SD are determined. If the difference in cortical index value is equal to or less than 10%, or if there is no difference in cortical index, normal bone density is diagnosed (i.e. the absence of osteoporosis).

Measurements in the symmetrical zones of the bone segments of both limbs on the x-ray are quite simple and allow the calculation of the cortical index (CI) under the same conditions. The values of the difference in the cortical index determining the presence of osteoporosis, osteopenia or mild osteoporosis and normal BMD in trauma patients are clinically confirmed by the authors. The authors performed a comparative radiography of the damaged and healthy contralateral bone segment on a single film in direct projection, with adjacent joints in 108 patients with unilateral lesion (nonunion), while a healthy limb had the possibility of normal functional load. On comparative radiographs, the thickness of the cortical plates on both limbs was determined at an equal distance from the joints and the diameter of the diaphysis at this level. The cortical Nordin-Barnett index was calculated (FIG. 1), the state of the bone structure was evaluated by the difference in the KI values (ΔKI) between the damaged and intact bone segments. Verification of the data was carried out according to the results of x-ray densitometry. The study of bone mineral density was performed on a DPXA X-ray densitometer (LUNAR, USA) in the lumbar spine, in the proximal sections of both thighs. When verifying the obtained data by X-ray densitometry, it was found that a decrease in the cortical index in the damaged segment by 15% or more corresponds to osteoporosis. The difference in the values of the cortical index of the affected and healthy bone segments 10% <ΔKI <15% corresponds to osteopenia or mild osteoporosis with a T-value from -2.5 to -2.7 SD. The difference in the values of the cortical index of 10% or less or the absence of a difference in the values of the cortical index of both limbs indicates that this patient has no osteoporosis. The diagnostic error of the method is 5%. Comparison of densitometry and determination of the cortical index showed that measuring the cortical index objectively reflects the state of bone mineral density in patients with nonunion of the bones of the lower extremities. Osteopenia and mild osteoporosis with a T-criterion from -2.5 to -2.7 SD (mild - determined by the authors in the study of trauma patients) are combined into one group (AKI within more than 10%, but less than 15%), so as in these cases, the tactics of treating trauma patients is the same.

Thus, the proposed method is quite simple and allows, subject to the unilateral defeat (non-union) of the limb, to identify osteoporosis, without using expensive research methods. This method is applicable in trauma patients, because allows you to arbitrarily choose the level of measurement of the cortical index for each patient, depending on the location of the fracture or the false joint.

The method is as follows.

In a patient with unilateral lesion (nonunion) of the limb before surgery, a quantitative assessment of the severity of osteoporosis is performed. For this, a comparative radiography of the damaged and healthy contralateral bone segment is carried out on one film in a direct projection, with adjacent joints. When comparing the X-ray in symmetrical areas, outside the damage zone, the thickness of the cortical plates on both limbs is determined at an equal distance from the joints and the diameter of the diaphysis at this level. For example, with localization of the false joint in the upper third of the diaphysis of the long bone, at a distance of 10-15 cm from the gap of the distal joint; with localization in the middle and lower thirds - at a distance of 10-15 cm from the gap of the proximal joint (for the thigh - at a distance of at least 15 cm). The cortical Nordin-Barnett index reflects the quantitative changes in the cortical and cancellous tubular bone, it is calculated by the formula:

where KI is the cortical index;

CD and XY are the thickness of the cortical layer;

AB is the diameter of the diaphysis.

The difference in the values of the cortical index of the damaged and healthy contralateral bone segment (ΔKI) is determined, and if the difference in the values of the cortical index of the affected and healthy limbs is equal to or more than 15%, osteoporosis is diagnosed. If the difference in the values of the cortical index is 10% <ΔKI <15%, osteopenia or osteoporosis of mild severity with a T-criterion from -2.5 to -2.7 SD are determined. If the difference in cortical index values is equal to or less than 10% or there is no difference in cortical index values of both limbs, the absence of osteoporosis in this patient is diagnosed.

This rule works when calculating the cortical index on both proximal and distal bone fragments, despite the high severity of osteoporosis in the distal extremities.

Clinical example 1. Patient B., 33 years old, was admitted to the clinic UNIITO. Diagnosis: pseudoarthrosis of the middle third of the left thigh, fracture outcome and osteosynthesis with an intramedullary shaft. The injury was 1 year 2 months old. The patient moved with a cane. Upon receipt, the intramedullary shaft is removed.

Since the defeat of the limb was one-sided, and the right limb was subjected to normal functional load, then the proposed method conducted a comparative x-ray of the damaged and healthy contralateral bone segments (Figure 2 - Radiograph of patient B. (arrows indicate the measurement level).

When measuring the diameter of the diaphysis and cortical layers of the proximal fragment at a distance of 15 cm from the slit of the hip joint, the following data were obtained:

Hip The width of the medial cortical layer, mm The width of the lateral cortical layer, mm Diaphysis diameter, mm KI Healthy leg 8 8 28 0.57 Stricken
leg 7 5 26 0.46

When comparing the KI on the affected and healthy hips, the difference in cortical indices ΔKI = 0.11 mm was obtained, which amounted to 19.2%. Since the decrease in CI on the affected limb was more than 15%, the patient is diagnosed with osteoporosis. The study of the BMD in this patient by x-ray densitometry confirmed the presence of osteoporosis with a T-criterion of -3.4 SD in the affected limb.

Clinical example 2. Patient M., 23 years old, was admitted to the clinic UNIITO. Diagnosis: pseudoarthrosis of the middle third of the right tibia, incorrectly fused fracture of the middle third of the fibula, outcome of the fracture and osteosynthesis of the Ilizarov apparatus. After an injury of 2 years 2 months, she moved with a cane, fixing her lower leg with an orthosis (unilateral lesion of the limb).

According to the proposed method, a comparative radiography of the damaged and healthy contralateral bone segment was carried out. The measurements were made at a distance of 10 cm from the ankle joint crack (Figure 3 - Radiograph of patient M. (arrows indicate the level of measurement).

The following data were obtained:

Hip The width of the medial cortical layer, mm The width of the lateral cortical layer, mm Diaphysis diameter, mm KI Healthy leg 3 four 23 0.30 Stricken
leg 3 3 22 0.27

When comparing the KI on the affected and healthy legs, the difference in cortical indices was obtained ΔKI = 0.03 mm, which amounted to 10.4%. Since the decrease in CI on the affected limb falls within 10% <ΔKI <15%, the patient is diagnosed with osteopenia. An examination of the BMD in this patient by x-ray densitometry confirmed the presence of osteopenia with a T-criterion of -1.8 SD in the affected limb.

Clinical example 3. Patient F., 48 years old, was admitted to the clinic UNIITO. Diagnosis: pseudoarthrosis of the left tibia in the lower third (lesion of the extremity unilateral).

According to the proposed method, a comparative radiography of the damaged and healthy contralateral bone segments was carried out. The measurements were made at a distance of 15 cm from the gap of the knee joint (Figure 4 - X-ray of the patient F. (arrows indicate the level of measurement). The following data were obtained:

When comparing the CI on the affected and healthy legs, there was no difference in cortical indices ΔKI = 0 mm. Since there was no decrease in CI on the affected limb (i.e., the difference in cortical index values is less than 10%), the patient is diagnosed with normal BMD, which is confirmed by X-ray densitometry: T-test -0.6 SD in the affected limb.

A method for quantitative assessment of osteoporosis by calculating the difference in the values of the cortical Nordin-Barnett index of damaged and healthy limbs is applicable provided that the lesion is one-sided and the normal functional load of a healthy limb is possible. The method is not applicable in the presence of periosteal strata (for example, as a result of previous osteosynthesis by a plate), with the sclerosing form of osteomyelitis, and in other cases, if it is impossible to accurately measure the thickness of the cortical layer.

Thus, the method allows to diagnose osteoporosis in trauma patients, it is simple, does not require additional costs, special training of a doctor and the availability of expensive equipment. The proposed method also allows to diagnose mild osteoporosis and osteopenia, which is impossible using standard technology. The ability to diagnose the early stages of osteoporosis allows you to timely choose the most optimal way of prevention and adjust treatment after surgery.

Claims (1)

A method for the diagnosis of osteoporosis, including the measurement of the size of the diameter of the tubular bone (AB), the total width of both cortical plates (CD, XY) and the subsequent calculation of the cortical index according to the formula KI = CD-XY / AB, characterized in that the measurements are carried out in symmetric areas of the bone segments of the affected and healthy limbs, followed by calculation of cortical indices for each of them, determine the difference in the values of the cortical indices of the affected and healthy limbs and with the difference in the values of cortical indexes equal to or more than 15% are diagnosed with osteoporosis, with a difference in cortical indices in the range of more than 10%, but less than 15% are diagnosed with mild osteopenia or mild osteoporosis with a T-criterion from -2.5 to -2.7 SD, and with the difference in cortical index values is less than 10% or the absence of a difference in cortical index values of both limbs is the normal bone mineral density.

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