1 Faculty of Medicine
Department of Radiology
Evaluation of Shenton´s line and reverse Shenton´s line evaluation in new-born pelvis plain radiographs
2
Faculty: Medical Faculty. Department: Radiology. Author: Luisa Fernandez Diaz.
Title: Shenton´s line and reverse Shenton´s line evaluation in the diagnosis of
developmental hip dysplasia.
Supervisor: Saulius Rutkauskas. Year: 2016/2017.
3
Table of contents:
Summary--- Page 4. Acknowledgements---Page 5. Conflicts of interest--- Page 6. Clearance issue by ethics commitee--- Page 7. Abbreviations---Page 8. Introduction--- Page 9. Aim and objectives of the thesis--- Page 10. Literature review--- Pages 11-17. Research methodology and methods---Page 18-20. Results and their discussion---Page 20-27. Conclusion---Page 28. Practical recommendations---Page 28. References---Page 29.
4
Summary:
The subject is contributing to discuss the reliability of the Shenton´s line and reverse Shenton´s line for the diagnosis of DDH. Measurements of AC angle, Shenton´s line, reverse Shenton´s line and rotation are done in normal and DDH patients.
The study sample was based on 98 paediatric patients, 53% were females and 45% males. The age varies from 7 till 278 days of life. The research data was collecting by the evaluation of 98 x-rays of paediatrics patients. The average of age was 100±40 days (min 7 max 278 days).
In our work, we have found that as the age increase the AC angle slowly decrease however, it was not statistically significant. We did not found any abnormal reverse Shenton´s line in our group. Additionally there was not a statistically significant correlation between the AC angle and Shenton´s line. According to our results rotation do not influence the presentation of Shenton´s line.
5
Acknowledgements:
I would like to express my sincere gratitude to my supervisor Saulius Rutkauskas for his great help in the research.
6
Conflicts of interest:
7
Clearance issued by the Ethics Committee: Date of issue: 2017/03/22
8
Abbreviations:
DDH- Developmental dysplasia of the hip. AC angle- Acetabular angle.
9
Introduction
The subject is contributing to discuss the clinical importance of the Shenton´s line and reverse Shenton´s line in normal patient to predict the usefulness in the developmental hip dysplasia.
Shenton´s and reverse Shenton´s lines are radiological parameters for the diagnosis of DDH but some studies have shown that they are not 100% accurate.
Developmental dysplasia of the hip (DDH) is a spectrum of anatomical
abnormalities of the hip joint in which the femoral head has an abnormal relationship to the acetabulum.
In case control and observational studies, female gender, breech positioning at delivery, Oligohydramnios, club foot, spinal dysraphism, arthrogryposis, generalised ligamentous laxity,family history of DDH, and increased birth weight (>4000 g) have been most consistently shown to have an association with the diagnosis of DDH. Most of the infants diagnosed with DDH have no identifiable risk factors.
Clinical presentations of DDH depend on the age of the child. New-borns present with hip instability; infants have limited hip abduction on examination; and older children and adolescents present with limping, joint pain, and osteoarthritis.
In the radiological evaluation, the relationship of the radiolucent femoral head and bony metaphysis to the acetabulum is important. The lines of Hilgenreiner, Perkins and Shenton serve as useful visual guides to recognize an abnormal relationship, particularly when the femoral head is still unossified. Acetabular index is another useful measurement, formed by the junction of Hilgenreiner's and a line drawn along the acetabular surface.
Ultrasound scanning is the investigation of choice to evaluate DDH in infants younger than six months of age. In developmental dysplasia of the hip, sonography can assess hip morphology and stability.
The goal of our work is to know the prevalence of broken Shenton´s line and reverse Shenton´s line in the normal patients and the value of these lines to diagnose the developmental hip dysplasia.
10
Aim and objectives:
1. Abstract of the thesis: The evaluation of Shenton´s line and reverse Shenton´s line is use for developmental hip dysplasia diagnosis but sometimes these lines are misleading. 2. Aim: To evaluate Shenton´s line and reverse Shenton´s line on X-Rays of new-born paediatric patients.
3. Objectives:
I. To evaluate AC angles on X-Rays of new-born paediatric patients.
II. To evaluate Shenton´s line and reverse Shenton´s line on X-Rays of new-born paediatric patients.
III. To evaluate rotation influence of new-born patients during x-ray into the presentation of the Shenton´s line and reverse Shenton´s line
11
Literature review: Definition of DDH:
Developmental dysplasia of the hip (DDH) is a spectrum of anatomical
abnormalities of the hip joint in which the femoral head has an abnormal relationship to the acetabulum.
The spectrum of DDH includes hips that are:
-Dysplastic: The hips have inadequate acetabulum formation. This disorder may not be clinically apparent but causes various radiographic abnormalities.
-Subluxated: The femoral head can be partially displaced outside of the acetabulum. -Dislocatable: The femoral head is located within the acetabulum but can be displaced by stress manoeuvres.
-Dislocated: The femoral head is completely outside the acetabulum. Dislocations are divided into two types:
— Teratologic dislocations: Teratologic dislocations occur early in utero and often are associated with other problems, such as Larsen syndrome, arthrogryposis, or spina bifida. These dislocations are extremely rare and usually require surgical treatment.
— Typical dislocations: Typical dislocations usually occur in healthy infants and may develop prenatally or postnatally.
Risk factors:
In case control and observational studies, female gender, breech positioning at delivery, Oligohydramnios, club foot, spinal dysraphism, arthrogryposis, generalised ligamentous laxity,family history of DDH, and increased birth weight (>4000 g) have been most consistently shown to have an association with the diagnosis of DDH. Most of the infants diagnosed with DDH have no identifiable risk factors. [1]
The left hip is involved three times as commonly as the right hip, perhaps related to the left occiput anterior positioning of most non-breech new-borns. In this position, the left hip resides posteriorly against the mother’s spine, potentially limiting abduction. [5]
The theory about the higher prevalence in female than in male is that girls are especially susceptible to the maternal hormone relaxin, which may contribute to ligamentous laxity with the resultant instability of the hip.
Epidemiology
DDH is not always detectable at birth, but some newborn screening surveys suggest an incidence as high as 1 in 100 newborns with evidence of instability, and 1 to 1.5 cases of dislocation per 1000 newborns[6].
12 The incidence is higher in cultures that still practice swaddling with the lower extremities fully extended and wrapped together. Studies in Native Americans showed, following a change from traditional swaddling to “safe swaddling”, a decrease in the prevalence of dysplasia from 6 times the United States average to the same prevalence as the rest of United States population. Similar experience was documented in Japan and Turkey.
Pathophysiology
DDH has multifactorial causes. Ligamentous laxity plays an important role, predisposing the developing hip to mechanical forces that cause the femoral head to move outside of the acetabulum. At birth, white children tend to have a shallow acetabulum, [8],[9] this may provide a susceptible period in which abnormal positioning or a brief period of ligamentous laxity may result in hip instability. Dysplasia a ppears to be the result of this process rather than the cause.[10]
Clinical Symptoms and Signs:
Clinical presentations of DDH depend on the age of the child. New-borns present with hip instability; infants have limited hip abduction on examination; and older children and adolescents present with limping, joint pain, and osteoarthritis.
Signs such as shortness of the femur with the hips and knees flexed that is called Galeazzi sign. Asymmetry of the thigh or gluteal folds and discrepancy of leg lengths may raise suspicion but are not specific findings for DDH.
The cornerstone of early detection is repeated, careful examination of all infants from birth and throughout the first year of life until a child begins walking.
Provocative testing includes the Barlow and Ortolani maneuvers. The Barlow test attempts to identify a dislocatable hip, while the Ortolani maneuver attempts to relocate a dislocated hip. A dislocatable hip has a distinctive ‘‘clunk’’ a feeling of instability. Both tests have been shown to have a high degree of operator dependence. Separating true dislocations (palpable clunks) from benign sounds (clicks) takes practice and experience. For physical examination, the child should be completely relaxed, on a smooth, warm, comfortable surface in a quiet environment. The examination must be performed with the diaper off and one hip is tested at a time. Very little force is required. In the Ortolani maneuver, the newborn is supine, and the hip is flexed to 90 degrees. The examiner’s index and middle fingers are placed over the greater trochanter and the thumb on the inside of the thigh. The hip is gently abducted while lifting the leg anteriorly. The Barlow test is the reverse manoeuvre. The leg is gently adducted with light pressure on the inside of the thigh with the thumb.
High-pitched clicks are often palpable or audible during the examinations. These clicks are benign and resolve with time. By 8 to 12 weeks of age, the Ortolani and Barlow tests are no longer reliable because of increased muscle tightness and decreased capsule laxity. [1]
Bilateral dislocation of the hip, especially at a later age, can be quite difficult to diagnose. This condition often manifests as a waddling gait with hyperlordosis. Many of the aforementioned clues suggesting a unilateral dislocated hip are absent, such as the
13 Galeazzi sign, asymmetric thigh and skin folds, or asymmetrically decreased abduction. Careful examination is needed and a high level of suspicion is important.
Of primary importance is making the diagnosis of hip dislocation or dysplasia. Once this diagnosis is made, the patient should be examined to make sure that there is no underlying medical or neuromuscular disorder. Proximal femoral focal deficiency can masquerade as hip dysplasia and often manifests similarly. Because the femoral head does not ossify, the radiographic appearance also may be deceiving. Other neuromuscular disorders can manifest as dysplasia later in life, such as Charcot-Marie-Tooth disease. [1]
Radiological Evaluation
After 4 to 6 months of age, radiography becomes more useful, for the nucleus of the femoral head ossifies at approximately 4 months (50th percentile) with a normal range of 2 to 8 months. An anteroposterior view of the hips in neutral position is routinely used in the screening for DDH. [1]
Evaluating the relationship of the radiolucent femoral head and bony metaphysis to the acetabulum is important. The lines of Hilgenreiner, Perkins and Shenton serve as useful visual guides to recognize an abnormal relationship, particularly when the femoral head is still unossified.
-Hilgenreiner's line is a line through the tri-radiate cartilages. (Fig.1)
-Perkin's line: drawn at the lateral margin of the acetabulum, is perpendicular to Hilgenreiner's line. (Fig.1)
-Shenton's line is a curved line that begins at the lesser trochanter, goes up the femoral neck, and connects to a line along the inner margin of the pubis. Shenton's line is smooth in the normally located hip with no step off. In the dislocated hip, Shenton's line has a step off because the femoral neck lies cephalic to the line from the pubis. (Fig.1)[7
Figure 1. Pelvis X-Ray (AP view) of one of our patient showing Hilgenreiner's line, Perkin’s line and normal Shenton’s line. Hilgenreiner's line is a line through the tri-radiate
14 cartilages. Perkin's line: drawn at the lateral margin of the acetabulum, is perpendicular to Hilgenreiner's line. Shenton's line is a curved line that begins at the lesser trochanter, goes up the femoral neck, and connects to a line along the inner margin of the pubis. Shenton's line is smooth in the normally located hip with no step off.
-Reverse Shenton´s line is a curve line that begins in the acetabular roof and ends in the femoral head. It should be continuous and smooth. (Fig.2)
Figure 2. Pelvis X-Ray (AP view) of one of our patient showing a normal reverse Shenton´s line. Reverse Shenton´s line is a curve line that begins in the acetabular roof and ends in the femoral head. It should be continuous and smooth.
In a normally located hip, the medial beak of the femoral metaphysis lies in the lower, inner quadrant produced by the intersection of Perkin's and Hilgenreiner's lines.
Acetabular index is another useful measurement, formed by the junction of Hilgenreiner's and a line drawn along the acetabular surface (Fig.3). In normal new-borns, the acetabular index averages 27.5 degrees, at six months 23.5 degrees and at two years, 20 degrees. Thirty degrees is considered the upper limit of normal [2].
In older children, center edge angle is a useful measure. It is the angle between the Perkin's line and the line joining the center of femoral head with the lateral acetabulum. In children aged 6–13 years, an angle greater than 19 is considered normal, while in older children an angle greater than 25 is considered normal. [2].
15 Figure 3. Pelvis X-Ray (AP view) of one of our patient showing the normal acetabular angles. Acetabular angle is a measurement formed by the junction of Hilgenreiner's and a line drawn along the acetabular surface.
Ultrasonography
Ultrasound scanning is the investigation of choice to evaluate DDH in infants younger than six months of age. It is also the only imaging modality that enables a three-dimensional real-time image of a neonate’s .In the first 4 to 6 months of life ultrasound is more sensitive than radiography because of incomplete ossification of the femoral head in early infancy hip.
Ultrasound findings during the first month of life often can reveal minor degrees of instability or acetabular immaturity that usually resolve spontaneously without any treatment.
Many countries of the Western world, routine ultrasound screening is recommended. It is difficult to perform routine screening in developing countries due to limited resources and expertise. However, it is generally agreed that infants belonging to the high-risk group need to undergo a screening ultrasound to diagnose DDH.
In developmental dysplasia of the hip, sonography can assess hip morphology and stability. Morphological acetabular dysplasia can be categorized by an α angle < 60 degrees (mild, 50 to 59 degrees; moderate, 43 to 49 degrees; severe < 43 degrees). [3].
The normal hypoechoic cartilaginous acetabular roof may be thicker and echogenic in the dysplastic hip, due to fibrous and deformed cartilage. The dysplastic femoral head may be smaller than the contralateral femoral head. In addition, the development of the echogenic central ossification center of the hip may be delayed in children with DDH. Frankly dislocated, dysplastic femoral heads will be superolaterally positioned and smaller than the contralateral femoral head, and the acetabular landmarks will not be identified on transverse imaging. In addition, a deformed labrum becomes echogenic and may become interposed between the acetabulum and femoral head.
16 Dynamic imaging is very important in determining the position and degree of femoral head instability in patients with developmental dysplasia of the hip.
The femoral head coverage ratio and the DCI will be < 50% in patients with DDH. Dynamic coverage indexes are rated as moderately subluxed (35 to 50%), severely subluxed (10 to 35%), and dislocated (< 10%) with or without reducibility. The involved hip may be hypermobile beyond the first days of life.
Initial sonographic findings after treatment that predict late sequela include a dynamic coverage index of 22%, an αangle < 43 degrees, and abnormal echogenicity of the cartilaginous roof.[2]
Sonography of the hip joint has become the standard of care for evaluation of developmental dysplasia of the hip, and it has gained more widespread acceptance for multiple additional pathological processes in both adults and children. The hip joint, tendons, and periarticular structures can be delineated with sonography in a variety of congenital, developmental, infectious, inflammatory, and arthritic conditions. Hip sonography can provide information superior to other imaging modalities by allowing both static and dynamic evaluations. Anatomical detail, stability of the neonatal hip, and movement of the iliopsoas tendon can be assessed with stress and provocative manoeuvres. The imaging accuracy in experienced hands, relative low cost, and lack of nonionizing radiation continue to make hip sonography a valuable imaging modality
Arthrography
Arthrography is a dynamic study, performed by injecting radiopaque dye into the hip joint and then carrying out a fluoroscopic examination, usually with the patient under anaesthesia.
Although it can be performed independently, it is routinely performed in conjunction with a closed reduction. Arthrography can be helpful in determining the underlying cartilaginous profile and dynamic stability of the hip. [4]
Has also been used in conjunction with a hip MRI study to facilitate demonstration of labral tears.
When arthrography is performed in combination with a closed reduction, the adequacy of the reduction can be assessed. Increased medial joint space, as demonstrated by medial pooling of the dye and a rounded or interposing limbus, may be indicative of poor long-term results.
After closed reduction and immobilization in a hip spica cast, a limited CT scan in the transverse plane is obtained to ensure the hip is not subluxated or dislocated posteriorly.
Magnetic resonance imaging provides excellent visualization of the infant hip. However, it is not routinely performed due to the need for sedation/general anesthesia to make sure the pelvis is still during the examination.[1]
17
Treatments options
The goal of treatment is to acquire and sustain a stable, concentrically reduced hip joint at an earliest possible age with minimal complications. The goals of treatment in older children with persistent acetabular dysplasia are to delay or prevent the
development of osteoarthritis and to obviate the need for arthroplasty at a relatively young age. The duration of therapy depends on the child’s age and severity of DDH.
The Pavlik harness is now considered the treatment of choice for DDH in infants younger than 6 months. It is a dynamic splint that prevents hip extension and adduction.
Multiple observational studies report high rates of DDH resolution without intervention in the new-born period. The high rates are believed to be due to ongoing growth and development of the femur and the acetabular cartilage.
The majority of paediatric orthopaedic surgeons recommend immediate treatment of infants with unstable hips on examination. Some paediatric orthopaedists will allow a few weeks of close observation and will only treat babies with an abnormality that persists at 3 to 4 weeks.[1]
For children older than 6 months, open or closed reduction is usually necessary. The use of triple diapers during the newborn period is no longer recommended
Complications
The Pavlik harness treatment is usually safe, but complications have been described like redislocation, stiffness of the hip, infection, blood loss, femoral nerve compression, delayed acetabular development, and knee subluxation and the most devastating, avascular necrosis of the femoral head. Numerous studies demonstrate that extreme abduction, especially when combined with extension and internal rotation, results in a higher rate of avascular necrosis. Bracing devices may cause skin irritation.
Differences in the lengths of the legs may persist despite appropriate treatment. Untreated, hip dysplasia will lead to arthritis and deterioration of the hip, which can be severely debilitating.
Prognosis
The prognosis for children treated for hip dysplasia is very good, especially if the dysplasia is managed with closed treatment. If closed treatment is unsuccessful and open reduction is needed, the outcome may be less favourable, although the short-term outcome appears to be satisfactory. If secondary procedures are needed to obtain reduction, then the overall outcome is significantly worse.[1]
18
Research methology and methods:
The research was carried in the Lithuanian University of Health Sciences (LUHS).The evaluation of AC angle, Shenton´s line and reverse Shenton´s line and rotation in LUHS normal patients are done.
The measurement of AC angle consist in drawing the Hilgenreiner line and then drawing a second line connecting the superolateral and inferomedial margins of the acetabular surface.(for better information about the AC angle check in the Literature review) (Fig.4)
Figure 4. Pelvis X-Ray (AP view) of one of our patient showing abnormal AC angle (>30º). Acetabular angle is a useful measurement formed by the junction of
Hilgenreiner's and a line drawn along the acetabular surface.
The evaluation of Shenton´s line consist in a precious look of this line that is an imaginary curved line that connect the medial border of femoral metaphysis with the superior border of the obturator foramen. It should create a smooth arc that is not disrupted.(Fig.5)
19 Figure 5. Pelvis X-Ray (AP view) of one of our patient showing Hilgenreiner's line, Perkin’s line and left sided disrupted Shenton’s line. Hilgenreiner's line is a line through the tri-radiate cartilages. Perkin's line: drawn at the lateral margin of the acetabulum, is perpendicular to Hilgenreiner's line. Shenton´s line is an imaginary curved line that connect the medial border of femoral metaphysis with the superior border of the obturator foramen. It should create a smooth arc that is not disrupted.
The evaluation of reverse Shenton´s line consist in a precious look of this imaginary curved line that goes from the acetabular roof until the femoral head. It should be continuous and smooth.
None of our patients have abnormal reverse Shenton´s line.
A proper not rotated hip x-ray should have a straight imaginary vertical middle line. This line begin from the middle of the sacrum bone, perpendicular to the transverse line and parallel to the sacral canal, goes to the middle part of Co4 until the pubic symphysis.
If this line ends in the middle of the symphysis pubic, there is no rotation in the radiological image (Fig.7). If this line slightly goes to the right in the pubic symphysis, there is a rotation to the right in the radiological image (Fig.6). If this line slightly goes to the left in the pubic symphysis, there is a rotation to the left in the radiological image.
20 Figure 6. Pelvis X-Ray (AP view) of one of our patient showing that the radiological image is rotated to the right.
Figure 7. Pelvis X-Ray (AP view) of one of our patient showing there is no rotation in the radiography.
21
Results and their discussion:
In the X-Ray of 98 normal paediatric patients are evaluated the AC angle, Shenton´s line and reverse Shenton´s line. From these patients 53% were females and 45% males.
The average of age was 100±40 days (min 7 max 278 days). Being in the male group the youngest at 40 days of life and the oldest at 234 days of life and in the female group the youngest at 7days of life and the oldest at 278 days of life. The Average of age in male was 99.5 days ± 33 days. The Average of age in female was 99 days ± 44 days.
In 23(23.5%) of our 98 patients are visible a broken Shenton´s line and in 0% of this 98 patient are visible a broken reverse Shenton´s line. The broken Shenton´s line appear in both hips in 17 patients (17.34%) of our 98 patients and in only one hip in 6 patients (6.12%) of our 98 patients, 3 (3%) patients of them in the right hip and 3patients (3%) of them in the left hip.
The AC angles of the right hip varies from 9.90º till 35.1º.The Average was 23º ± 5º. The AC angles of the left hip varies from 13.30 ºtill 33.5º.The average was 23.5º ± 4.5º.
AC angle both hips
AC angle of both hip varies from is 35.1º as maximum till 9.9º as minimum. The Average was 23.4º ± 5 º.
AC ANGLES
FEMALE MALE BOTH
RIGHT LEFT RIGHT LEFT RIGHT LEFT
23,5º± 5º 24º±4º 23º± 4,5º 22º±4,5º 23º±5º 23,5º±4,5º Table 1. Average and Standard deviation of AC angles.
Correlation between the age and AC angles.
We compared three variables to calculate the relation between each other. The first comparison was the age with the right hip AC angles and the second comparison was the age with the left hip AC angles.
Correlation between the Age and right AC angles
We compared two variables to calculate the relation between each other. The first variable is the age and the second variable is the right hip AC angles. (Graph 1).
-Correlation: -0.08
This is a negative but weak relationship between the two variables (P-value: 0.435.). The p value is more than 0.05, showing there is no significant correlation between Age and AC angle (right).
22 Graph 1. Correlation between the age and the AC angle of the right hip.
Correlation between the Age and left AC angles
We compared two variables to calculate the relation between each other. The first variable is the age and the second variable is the left hip AC angles. (Graph 2).
-Correlation:-0.117
This is a negative correlation. The p value is more than 0.05, showing there is no significant correlation between Age and AC angle (left). P-value: 0.249.
Graph 2.Correlation between the age and the AC angle of the left hip. 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 300 A C Ang le(R ig h t Leg )
Age (in days)
0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 300 A C Ang le (Lef t Leg )
23 Figure 8. Pelvis X-Ray (AP view) of one of our patient showing abnormal AC angle (>30º). Acetabular angle is a useful measurement formed by the junction of
Hilgenreiner's and a line drawn along the acetabular surface.
Correlation between the AC angles and Shenton´s lines.
We compared three variables to calculate the relation between each other. The first comparison was the Shenton´s line with the right hip AC angles and the second comparison was the Shenton´s line with the left hip AC angles. The used method to make these calculations was the Eta correlation method. This method is use when we want to find correlation between nominal variables (Shenton´s line) and quantitative values (AC angles).
Shenton´s line VS AC angles (right)
We compared two variables to calculate the relation between each other. The first variable is the Shenton´s line and the second variable is the right hip AC angles. -Correlation: 0,090
This is a positive but weak relationship between the two variables because p value is above 0.05. P-value: 0.906.
Shenton´s line VS AC angles (left)
We compared two variables to calculate the relation between each other. The first variable is the Shenton´s line and the second variable is the left hip AC angles.
- Correlation: 0,076
This is a positive but weak relationship between the two variables because p value is above 0.05. P-value: 0,857.
24 We compared three means to calculate the relation between each other . The first comparison was the Shenton´s line with the right hip AC angles and the second
comparison was the Shenton´s line with the left hip AC angles. The used method to make these calculations was the Student´s T-test method. Since both angles were distributed by normal law for abnormal and normal Shenton´s line. ( Table 2)
Shenton´s line N Mean Std. Deviation Pvalue AC ANGLES RIGHT NORMAL 75 23,0467 4,67319 0.381 BROKEN 23 24,1000 6,03392 AC ANGLES LEFT NORMAL 75 23,2920 4,53049 0.459 BROKEN 23 24,0913 4,42215 ,
Table 2. Student´s t test was used to compare angles means. Results of comparison of means of AC angles VS Shenton´s line.
P value not significant difference between the group of normal and abnormal Shenton´s lines.
Figure 9. Pelvis X-Ray (AP view) of one of our patient showing Hilgenreiner's line, Perkin’s line and left sided disrupted Shenton’s line. Hilgenreiner's line is a line through the tri-radiate cartilages. Perkin's line: drawn at the lateral margin of the acetabulum, is perpendicular to Hilgenreiner's line. Shenton´s line is an imaginary curved line that connect the medial border of femoral metaphysis with the superior border of the obturator foramen. It should create a smooth arc that is not disrupted.
25
Correlation between the rotation and Shenton´s line.
We compared three variables to calculate the relation between each other. The first comparison was the no radiological rotation with the broken Shenton´s line, the second comparison was the Right side rotation with the broken Shenton´s line and the third comparison was the left side rotation with the broken Shenton´s line .The used method to make these calculations was the Pearson Chi square method. To evaluate the strength of the comparison Cramer´s coefficient test is use. (Graph 3)
-Correlation: 0.082 (very weak)
This is a positive but weak relationship between the two variables because p value is above 0.05. P-value: 0.717.
-During rotation, 25.8% of our patients shows a broken Shenton´s line -During left rotation, 24.1% of our patients shows a broken Shenton´s line. -During right rotation, 27%of our patients shows a broken Shenton´s line. -During NO rotation, 18.8% of our patients shows a broken Shenton´s line.
Graph 3. Graph shows the appearance of the broken Shenton’s line when the x-ray is rotated or when is not rotated.
Correlation between the rotation with the Shenton´s line of the right hip.
We compared two variables to calculate the relation between each other. The first variable is the rotation and the second variable is the Shenton´s line of the right hip. (Graph 4) -Correlation: 0.151 25,8% 18,8% 74,2% 81,3% 0,0% 10,0% 20,0% 30,0% 40,0% 50,0% 60,0% 70,0% 80,0% 90,0% ROTATION NO ROTATION
ROTATION VS SHENTON´S LINE
26 This is a positive but weak relationship between the two variables because p value is above 0.05. P-value: 0.328.
During left rotation: 20.7% of our patients shows a right hip broken Shenton´s line. During right rotation: 27%of our patients shows a right broken Shenton´s line. During NO rotation: 12.5% of our patients shows a right broken Shenton´s line.
Graph 4. Graph shows the appearance of the broken Shenton’s line in the right hip when the x-ray is rotated or when is not rotated.
Correlation between the rotation with the Shenton´s line of the left hip.
We compared two variables to calculate the relation between each other. The first variable is the rotation and the second variable is the Shenton´s line of the left hip. (Graph 5)
-Correlation: 0.090
This is a positive but weak relationship between the two variables because p value is above 0.05. P-value: 0.670.
During left rotation: 20.7% of our patients shows a left hip broken Shenton´s line. During right rotation: 24.3%of our patients shows a left broken Shenton´s line. During NO rotation: 15.6% of our patients shows a left broken Shenton´s line
12,5% 20,7% 87,5% 79,3% 0,0% 10,0% 20,0% 30,0% 40,0% 50,0% 60,0% 70,0% 80,0% 90,0% 100,0% ROTATION NO ROTATION
ROTATION VS RIGHT SHENTON´S LINE
27 Graph 5. Graph shows the appearance of the broken Shenton’s line in the left hip when the x-ray is rotated or when is not rotated.
We did not find any broken reverse Shenton´s line in our 98 patients.
The correlation between the Age and AC angle shows that is negative and not significant. As age increase, the AC angle of the right hip decrease but they don´t affect each other that much.
The correlation between the Shenton´s line and AC angle shows that is positive and not significant.
The correlation between the rotation and Shenton´s line shows that is positive and not significant.
Rhee PC, Woodcock JA in the Academic Network for Conservational Hip Outcomes Research Group. J Bone Joint Surg Am. 2011 May; 93 Suppl 2:35-9. doi: 10.2106/JBJS.J.01717[11]. Their conclusion is the Shenton line is a reliable and accurate radiographic marker to detect superior femoral head subluxation indicative of acetabular dysplasia. The conclusion of our work is that the Shenton´s line is not a reliable and accurate marker for DDH diagnosis due to our findings of broken Shenton´s line in normal paediatric patients.
Emmanouil Morakis, Rachel Buckingham, Tim Theologis, Andrew Wainwright, Michael Benson Nuffield Orthopaedic Centre, Oxford, UKTitle The “Reverse Shenton’s line” in the diagnosis of developmental dysplasia of the hip in children under 18 months of age[12]. Their conclusion is the “reverse Shenton’s line” is an accurate and reliable radiographic sign in the diagnosis of DDH in children younger than 18 months of age. It shows better specificity than the “Shenton’s line” in the group of non-orthopaedic doctors. We did not find any broken reverse Shenton´s line in our 98 paediatric patients, for this reason we cannot compare our work with this article.
15,6% 20,7% 84,4% 79,3% 0,0% 10,0% 20,0% 30,0% 40,0% 50,0% 60,0% 70,0% 80,0% 90,0% ROTATION NO ROTATION
ROTATION VS LEFT SHENTON´S LINE
28
Conclussion:
1. We have found that as the age increase the AC angle slowly decrease however, it was not statistically significant.
2. We did not found any abnormal reverse Shenton´s line in our group. Additionally there was not a statistically significant correlation between the AC angle and Shenton´s line.
3. According to our results rotation do not influence the presentation of Shenton´s line.
Practical recommendations:
The Shenton´s line and reverse Shenton´s line should be used very carefully for patient with DDH diagnosis because our data shows broken lines even in normal paediatrics patients.
29
References:
1.Polina Gelfer, MD, FAAP, & Kathleen A. Kennedy, MD, MPH. Bridgeport Health Department, Bridgeport, Connecticut. MD University of Texas Medical School at Houston, Texas. Pediatr Health Care. (2008). 22, 318-322.
2. Shahryar Noordin, Masood Umer, Kamran Hafeez, Haq Nawaz Section of Orthopedics, Dept. of Surgery, Aga Khan University, Karachi, Pakistan Orthopedic Reviews 2010; volume 2:e19
3. Alexiev VA, Harcke HT, Kumar SJ. Residual dysplasia after successful Pavlik harness treatment: early ultrasound predictors. J Pediatr Orthop 2006;26:16–23
4. Henle P, Tannast M, Siebenrock KA. [Imaging in developmental dysplasia of the hip]. Orthopade. 2008 Jun. 37 (6):525-31.
5. Wynne-Davies R (1970) Acetabular dysplasia and familial joint laxity: two
etiological factors in congenital dislocation of the hip: a review of 589 patients and their families. J Bone Joint Surg Br52:704–716.
6. Barlow TG. Early diagnosis and treatment of congenital dislocation of the hip. J Bone Joint Surg Br. 1962. 44-B:292-301
7. Roposch Andreas, Nicole M. Moreau, Elizabeth Uleryk and Andrea S. Doria.
“Developmental Dysplasia of the Hip: Quality of Reporting of Diagnostic Accuracy for US1.” Radiology 241, no. 3 (December 2006): 854-860.
8. McKibbin B. Anatomical factors in the stability of the hip joint in the newborn. J Bone Joint Surg Br. 1970 Feb. 52(1):148-59.
9.Rális Z, McKibbin B. Changes in shape of the human hip joint during its development and their relation to its stability. J Bone Joint Surg Br. 1973 Nov. 55(4):780-5.
10. Skirving AP, Scadden WJ. The African neonatal hip and its immunity from congenital dislocation. J Bone Joint Surg Br. 1979 Aug. 61-B(3):339-41.
11. Rhee PC, Woodcock JA, Clohisy JC, Millis M, Sucato DJ, Beaulé PE, Trousdale RT, Sierra RJ; The Shenton line in the diagnosis of acetabular dysplasia in the skeletally mature patient. Academic Network for Conservational Hip Outcomes Research Group.. J Bone Joint Surg Am. 2011 May;93 Suppl 2:35-9. doi: 10.2106/JBJS.J.01717.
12. Emmanouil Morakis, Rachel Buckingham, Tim Theologis, Andrew Wainwright, Michael Benson Nuffield Orthopaedic Centre, Oxford, UKTitle The “Reverse
Shenton’s line” in the diagnosis of developmental dysplasia of the hip in children under 18 months of age.
