|Year : 2016 | Volume
| Issue : 2 | Page : 85-89
Does Q angle change in spastic diplegia children?
TU Jimshad1, Sanam Mainali2, KS Swethankh3, Anil T John4
1 Assistant Professor, Dayananda Sagar College of Physiotherapy, Bangalore, Karnataka, India
2 Intern, Dayananda Sagar College of Physiotherapy, Bangalore, Karnataka, India
3 Chief Physiotherapist, Specialist Rehabilitation Centre, Mysore, Karnataka, India
4 Principal, Dayananda Sagar College of Physiotherapy, Bangalore, Karnataka, India
|Date of Web Publication||12-Apr-2017|
Dayananda Sagar College of Physiotherapy, Shavige Malleshwara Hills, KS Layout, Bengaluru - 560 078, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Spastic diplegia is a form of cerebral palsy that is a chronic neuromuscular condition of hypertonia and spasticity manifested as an especially high and constant tightness or stiffness in the muscles of the lower extremities of the human body, usually those of the legs, hips, and pelvis. Q angle is an angle formed by two imaginary lines, first line extending from anterior superior iliac spine to center point of patella and second line extending from tibial tuberosity to center point of patella. The abnormal twisting of patella is known as tibial torsion.
Objectives: To find Q angle value in male children with spastic diplegia aged between 7 and 12 years and to compare the degree of Q angle between children with internal and external tibial torsion.
Methodology and Procedure: A total of thirty male children aged between 7 and 12 years were divided into two groups based on their tibial torsion, and Q angle was assessed using standard goniometer.
Results: Results were statistically analyzed. There was a significant change in Q angle of children with spastic cerebral palsy, and children with spastic diplegia with internal tibial torsion have decreased Q angle and children with external tibial torsion have a significant increase in their Q angle (P = 0.001).
Conclusion: This study concludes that Q angle is a good outcome variable for assessing musculoskeletal problem related to lower limb and can be used as a major tool for prognosis during rehabilitation. This study also proves that children with spastic diplegia with internal tibial torsion have decreased Q angle and children with external tibial torsion have a significant increase in their Q angle.
Keywords: Q angle, spastic diplegia, tibial torsion
|How to cite this article:|
Jimshad T U, Mainali S, Swethankh K S, John AT. Does Q angle change in spastic diplegia children?. Indian J Cereb Palsy 2016;2:85-9
| Introduction|| |
Cerebral palsy (CP) is considered a neurological disorder caused by a nonprogressive brain injury or malformation that occurs while the child's brain is under development which primarily affects body movement and muscle coordination. CP affects body movement, muscle control, muscle coordination, muscle tone, reflex, posture, and balance. It can also impact fine motor skills, gross motor skills, and oral motor functioning. The motor disorders of CP are often accompanied by disturbances of sensation, cognition, communication, perception, and/or behavior and/or by a seizure disorder. Spastic diplegia, historically known as Little's disease, is a form of CP that is a chronic neuromuscular condition of hypertonia and spasticity manifested as an especially high and constant tightness or stiffness in the muscles of the lower extremities of the human body, usually those of the legs, hips, and pelvis. Spastic diplegic cerebral palsy patients have more extensive involvement of the lower extremity than the upper extremity. This allows most people with spastic diplegia cerebral palsy to eventually walk. Approximately 2 in 1000 live born children having cerebral palsy. Globally, the reported incidence and prevalence of CP varies by region, population, age, and severity, which may limit the generalizability of population-based results. Around 77% of CP is spastic diplegia type., In many children, the cause of CP is unknown. Possible causes include genetic abnormalities, congenital brain malformations, maternal infections or fevers, fetal injury, twins or multiple births, low birth weight, infertility treatments, birth complications, Rh incompatibility, premature birth, assisted reproductive technology, infertility treatments, medical conditions of the mother, exposure to toxic substances, breech presentation, and low Apgar score.,,
The Q angle was first defined by Brattstrom. He described the Q angle as an angle with its apex at the patella and formed between the ligamentum patellae and the extension of the line formed by the quadriceps femoris muscle resultant force. It was later measured using the anterior superior iliac spine (ASIS) as the proximal landmark. The Q angle provides an estimate of the vector force between the quadriceps femoris muscle and the patellar tendon. It is formed by the crossing of two imaginary lines. The first line extends from the ASIS to the center of the patella (CP). The second line is drawn from the tibial tuberosity (TT) to the CP. The angle formed between these two lines represents the Q angle. The Q angle has come to be accepted as an important factor in assessing knee joint function. The values of Q angle in a child's knee cover a wide range. Frequently, its extreme values are responsible for complaints or the appearance of some pathological conditions (e.g., chondromalacia and recurrent dislocation of patella). Any variation in Q angle, either less or more, can lead to gait abnormality as well as increased susceptibility to injuries. Although numerous studies on the Q angle have been conducted worldwide, relatively few of them have focused on Q angle in children population. The values of Q angle documented by various researchers in literature vary. The normal range of Q angle for children aged between 7 and 12 years is: males – 13.1 ± 3.5 (range: 10–17) and females – 13.7 ± 4.9 (range: 10–19). Females tend to have slightly higher Q angle because of their wider pelvis. It is evident that lower extremity alignment characteristics may change the position of the anatomical landmarks used to measure the Q angle, thus impacting its magnitude, mainly the alignment of femur and tibia. Tibial torsion is the angle between the transverse axis of the knee and the transmalleolar axis. Internal tibial torsion is inward twisting of the tibia and is the most common cause of intoeing. It affects males and females equally and is often asymmetrical with the left side affected more than right. The cause is believed to be intrauterine position, sleeping in the prone position after birth, and sitting on the feet. The child with internal tibial torsion walks with the patella facing forward and the feet pointing inward. External tibial torsion is outward twisting of tibia and is usually a common cause of an out-toe gait. External tibial torsion is usually seen between 4 and 7 years of age. It is often unilateral and more common on the right side. The tibia rotates laterally with growth, making lateral tibial torsion worse. Femoral anteversion describes the normal position of the femur, which is medially rotated on its long axis at birth. It is often familial and is usually bilateral, affecting females more than males. The child with increased femoral anteversion walks with his or her patellae and feet pointing inward. The gait appears clumsy, and the child may trip as a result of crossing his or her feet. Objectives of this study were to find Q angle value in male children with spastic diplegia aged between 7 and 12 years and to compare the degree of Q angle between children with internal and external tibial torsion.
| Methodology and Procedure|| |
A total of thirty male children aged 7–12 years who were diagnosed with spastic diplegia were included as the study sample. The study design was observational, cross-sectional study which was carried out in pediatric rehabilitation centers in Mysore and Bengaluru. Sample was collected on the basis of convenience sampling after giving due consideration to inclusion and exclusion criteria. The inclusion criteria were male children aged between 7 and 12 years diagnosed with spastic diplegia cerebral palsy and children who were at least able to stand with minimum support. Exclusion criteria were children who had undergone prior orthopedic surgery at lower extremities, children who were having systemic or localized infections, and children with severe contracture.
Informed consent was obtained from parents of children before assessment, and ethical clearance has been obtained from the Ethical Committee of Dayananda Sagar College of Physiotherapy, Bengaluru. Children were then divided into two groups: Group A included 15 children with internal tibial torsion and Group B included 15 children with external tibial torsion. Tibial torsion was measured by assessing thigh–foot angle. Data were collected by measuring Q angle with the use of standard goniometer. In both groups, Q angle was assessed with children lying in supine position to maintain homogeneity of the data.
Measurement of Q angle
A standard goniometer was used to measure the Q angle. The measurement of the Q angle was performed with all the children lying in supine position and keeping the pelvis square. For marking center point of patella, borders of patella were palpated, and the outline marking the patella was drawn using a pen. The point of intersection of maximum vertical and transverse diameters of patella was marked as center point (CP). The point of maximum prominence was marked as the TT. A straight line was drawn from ASIS to CP using the straight edge of measuring tape. The second was drawn from CP to TT. The angle formed between these two lines was measured using standard goniometer.
Measurement of tibial torsion
Tibial torsion was assessed with thigh–foot angle. The assessment was performed with children lying in prone position and knee flexed to 90° and ankle in neutral position. The axis of thigh and the axis of foot were noted, and the angle between the two axes was measured as thigh–foot angle. Negative thigh–foot angle denoted internal tibial torsion and positive thigh–foot angle denoted external tibial torsion.
Measurements were taken once by a single investigator. Data were analyzed using SPSS software for Window (version 17, Chicago, USA), and P value was set as 0.05. Descriptive statistics and Chi-square test were used to analyze baseline data for demographic data. Paired and unpaired t-test used to find the significance of difference in Q angle among within the groups and between the groups.
| Results|| |
[Table 1] shows baseline characteristics of thirty children considered for the study [Diagram 1]. Mean age of Group A was 8.73 and Group B was 8.67 which was not statistically significant (P > 0.898). Mean body mass index of Group A was 17.13 and Group B was 16.80 which was not statistically significant either (P > 0.609).
[Table 2] compares the limb length between left and right leg of individual children in both the groups [Diagram 2]. The mean limb lengths of children in Group A were 52.13 (left leg) and 52.07 (right leg) which was not statistically significant (P > 0.967) and in Group B were 52.47 (left leg) and 52.53 (right leg) which was not statistically significant either (P > 0.957). Similarly, [Table 3] compares the Q angle of left and right knee of individual children [Diagram 3]. In children of Group A, the left knee mean Q angle was 6.40 and right knee was 6.47. In Group B, the left knee mean Q angle was 22.60 and right knee was 22.40. Both the results were statistically insignificant with P > 0.887 and P > 0.670, respectively. [Table 4] is of importance and provides stable support to the conclusion of this study [Diagram 4]. The left knee mean Q angle of Group A was 6.40 and Group B was 22.60 with P < 0.0001 and right knee mean Q angle of Group A was 6.47 and Group B was 22.40 with P < 0.0001. The results obtained in [Table 4] were statistically significant. It shows that the Q angle of the children in Group A, i.e., children with internal tibial torsion showed a decrease in Q angle, whereas the children in Group B, i.e., children who had externally rotated tibia showed a significant increase in Q angle.
| Discussion|| |
The purpose of this current study was to find Q angle value in male children with spastic diplegia aged between 7 and 12 years and to compare the degree of Q angle between children with internal and external tibial torsion. Q angle can be taken as one of the measures to assess the prognosis during rehabilitation as well as to plan the treatment protocol. Children included in this study were aged above 7 years; Q angle might not be used as an assessment tool for children below 7 years of age because of the continuous physiological changes occurring in the lower extremity alignment. Genu varum and medial tibial torsion are normal in newborn and infants, and maximal varus is present at 6–12 months of age. With normal growth, the lower limbs gradually straighten, but with further normal development, knees gradually drift into valgus. This valgus deformity is maximal at around age 3–4 years. Finally, the genu valgum spontaneously correct by the age of 7 years to that of the adult alignment of the lower limbs., Excessive genu valgum witnesses increase in Q angle, whereas there is a decrease in Q angle is noticed in case of genu varum. Literature support for this study was very less as there was very few studies related to Q angle and pediatric population, especially children with cerebral palsy. Hence, in this study, most of the statement for result was a hypothetical statement, children with spastic diplegia have abnormal alignment of lower limb changing the position of anatomical landmarks used to measure Q angle. In this study, children who had their tibia rotated externally showed increased degree of Q angle. In case of external tibial torsion, the patella is found to move medially relative to the ASIS and the TT also moves laterally, thus increasing the Q angle. Likewise, children with internal tibial torsion had decreased Q angle. This could be due to the displacement of patella laterally relative to ASIS and medial displacement of TT due to internal tibial torsion. In most of spastic children, femur is found to be internally rotated, i.e., femoral anteversion. Excessive femoral anteversion is associated with an in-toe gait. To compensate the excessive intoeing, there occurs adaptive external rotation of tibia on femur once the child starts walking. However, the children included in this study were not subjected to walking independently; thus compensatory rotation of tibia had not occurred yet. The inability to measure femoral torsion, tibiofemoral angle, or measurement of knee alignment is a limitation of this study because of unwillingness to expose the children to radiation; however, the tibial torsion is measured with thigh–foot angle with children lying in prone position and knee flexed to 90° and ankle in neutral position. Similarly, less sample size and no Modified Ashworth Scale (MAS) measurement are other limitations.
| Conclusion|| |
After analyzing results from the current study and support from past literatures, this study concludes that Q angle is a good outcome variable for assessing musculoskeletal problem related to lower limb. In case of children with spastic diplegia, there occurs a deviation of Q angle from its normal range which can be used as a major tool for prognosis during rehabilitation. This study also proves that children with spastic diplegia with internal tibial torsion have decreased Q angle and children with external tibial torsion have a significant increase in their Q angle.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]