Radiologic Evaluation of the Distal End Radius Indices in Indian Paediatric Population

Abstract

Background

The distal end radius's bony anatomy in relation to three variables—Radial Inclination, Volar tilt, and radial height—has been discussed commonly in the adult population and is not very well defined in the growing skeleton. In children aged 8–16 years old, we measured the osseous distal end radius according to radiography standards. The research comprised 130 patients, 65 males and 65 females aged 8–16. In each child, the norms for radial inclination, volar tilt, and radial epiphyseal height were established. This research defines these radiographic parameters for the paediatric population in India for the first time.

Methods

This research is an Unicentric Cross-sectional observational analytical study. We studied 130 normal wrist posteroanterior and lateral radiographs of the Indian paediatric population aged 8–16 years who reported to our OPD and calculated the three parameters—(1) Radial height, (2) Volar Tilt, and (3) Radial Inclination. Mean measurement values were analysed statistically.

Results

The Mean distal end radius volar tilt is 10.92° ± 1.76° SD with a range from 4° to 15°. The Mean distal end radial inclination is 21.04° ± 2.10° SD with a range from 15° to 25°. The Mean distal end radial height is 11.93 ± 1.44 mm SD with a range from 9.0 to 14.50 mm.

Conclusion

In true Postero-anterior and lateral wrist radiographs of the Indian paediatric population, we have established normal values that may be utilized as a guide for the evaluation and treatment of a variety of traumatic and non-traumatic problems in Indian children.

Introduction

Adult diseases affecting the wrist and distal end radius have been treated clinically using the often-discussed factors of volar tilt (additionally known as palmar inclination or palmar tilt), radial height, and radial inclination, linked to the osseous structure of the adult distal end radius [1]. To our knowledge, there has been no study conducted to identify the standard values of volar tilt, radial inclination and radial height in the Indian paediatric population. We looked at the radiographic measures of the typical osseous anatomy of the distal end radius in the paediatric population of India.

Materials and Methods

This research is an Unicentric Cross-sectional observational analytical study. Once our institution's research and ethical committee had given its approval (IEC/42/43), we studied 130 normal wrist posteroanterior and lateral radiographs of the Indian paediatric population aged 8–16 years reporting to our OPD and calculated the three parameters- (1) Radial height, (2) Volar Tilt, and (3) Radial Inclination. Mean measurement values were analysed statistically. The radiographs were taken for different reasons. Routinely in our practice, in the paediatric age group, we prefer doing bilateral forearm radiographs for comparison of the affected side with the normal side in the upper limb (forearm) trauma cases. Forearm radiographs are also routinely performed in cases of children with spinal deformity [2] and coronal plane deformities of the knees to assess the skeletal growth that determines the modality of treatment in these patients. In patients with contralateral non-traumatic pathology, radiographs were also collected for comparison with the unaffected side. We selected 16 as our cut-off age because it is likely that by then both males and females would have attained skeletal maturity [3]. We have chosen the lower limit of age to be 8 years because of several reasons. Firstly, the ossification of the last carpal bone, the Pisiform, typically occurs between the ages of 8 and 12 years. This facilitates the measurement of parameters around the distal radius during this age range. Secondly, according to a study by Gandhi RK et al. [4], most deformities of the distal third of the radius tend to fully correct within 5 years after the fracture. Considering that the distal radial epiphysis may fuse at any time between 15 and 25 years (Caffey, 1956) [5], there is a greater reluctance to accept angular deformities in children over 8–10 years of age. Thirdly, remodelling is proportional to the remaining growth potential and is more pronounced in younger children (< 8 years) [6]. Additionally, remodelling is reduced in the upper extremities compared to lower extremities, probably because the lower extremities are subjected to greater mechanical loads [7]. Based on these considerations, we established a lower limit of 8 years for our study as restoration of the normal anatomy after this age group should have no/less margin of error. Every radiograph was thoroughly examined, and we eliminated any patients who exhibited bilaterally visible signs of acute or chronic damage or deformity at the distal end of the radius. To get our measurements, we employed the Postero-anterior and lateral radiographs. Only true lateral radiographs—defined as having the ulnar head entirely superimposed behind the radius—have been used in the research [8–10]. True PA criteria include the distal radius ulna joint having no or minimum overlap, the metacarpal bases having no or minimal overlap, and the ulnar styloid process beginning from the medial ulnar cortex of the ulna bone [8–10]. On the AGFA Healthcare workstation, the radiographs had to be modified such that the magnification was set to 100% size (true size). We may view the radiographs from this computer workstation and use the computer to draw lines and angles. Instantaneously, the workstation displays the length in millimetres or centimetres and the angle in degrees. Only one observer supplied these length and angle values into the data collecting form.

Technique

Volar Tilt: On a lateral radiograph of the wrist, it is calculated as the angle between a line drawn perpendicular to the long axis of the radius and a tangent line drawn along the slope of the dorsal-to-palmar surface of the radius (as shown in Fig. 1). A normal Indian adult Volar tilt is 4°–17° [11].

Fig. 1.

True lateral view showing measurement of volar tilt on AGFA workstation

Radial Inclination: It is calculated on Postero-anterior view as the angle between a line drawn parallel to the radius's long axis and a line drawn along the distal radius's articular surface (as shown in Fig. 2). A normal Indian adult radial inclination is 21°–33° [11].

Fig. 2.

True postero-anterior view of wrist showing measurement of radial inclination angle on AGFA workstation

Radial Height (Distal Radial Epiphyseal Height): Because the distal radius physis hampers the measurement of radial height in children, we have measured the height of the distal end radius physis instead of the radial height (as shown in Fig. 3). A normal Indian adult radial height is 9.1–16.7 mm [11].

Fig. 3.

True postero-anterior view of wrist showing measurement of radial height on AGFA workstation

Results

The research comprised 130 patients, 65 boys and 65 girls, varying in age from 8 to 16 years. For each patient in the aforementioned age range, the normal range of values for radial inclination, volar tilt, and radial epiphyseal height was established. The range of values of radial epiphyseal, volar tilt, and radial inclination height and their variations with gender and age are summarized in Tables 1, 2, 3.

Table 1.

Descriptive statistics of various parameters in the study (N = 130)

	Mean (SD)	Median	Range
Volar tilt (degrees)	10.92 (1.76)	11.00	4.0–15.0
Radial inclination (degrees)	21.04 (2.10)	21.00	15.0–25.0
Radial height (mm)	11.93 (1.44)	12.00	9.0–15.0

Table 2.

Gender and mean (SD) of various parameters in the study

	Volar tilt (degrees)	Radial inclination (degrees)	Radial height (mm)
Female	11.20 (1.71)	21.78 (1.82)	11.87 (1.52)
Male	10.63 (1.77)	20.29 (2.11)	11.99 (1.36)
P value	0.065	< 0.001	0.652

Table 3.

Age and mean (SD) of various parameters in the study

Age (years)	Volar tilt (degrees)	Radial inclination (degrees)	Radial height (mm)
8–10 (n = 65)	9.92 (1.66)	19.62 (1.65)	10.91 (0.94)
11–13 (n = 41)	11.34 (0.99)	21.80 (1.24)	12.45 (0.86)
14–16 (n = 24)	12.87 (0.94)	23.58 (1.01)	13.80 (0.87)
P value	< 0.001*	< 0.001*	< 0.001*

The mean values and the normal range of the three parameters in the Indian paediatric population aged 8–16 years old are summarised in Table 1. The Mean distal end radial volar tilt is 10.92° ± 1.76° SD with a range from 4° to 15°. The Mean distal end radial inclination is 21.04° ± 2.10° SD with a range from 15° to 25°. The Mean distal end radial height is 11.93 ± 1.44 mm SD with a range from 9.0 to 14.50 mm.

The variations of these values with gender are summarised in Table 2 and Fig. 4. Mean distal end radial Volar Tilt is 11.20° (± 1.71°) in females which is more than that in males at 10.63° (± 1.77°). Mean distal end Radial Inclination is 21.78° (± 1.82°) which is more than that in males at 20.29° (± 2.11°). Mean distal end radial height is 11.99 mm (± 1.36 mm) in males which is more than that in females at 11.87 mm (± 1.52 mm).

Fig. 4.

Variations of parameters with gender

The variations of these parameters with increasing age are summarised in Table 3; Figs. 5, 6. All these values demonstrated an increasing trend with an increase in age. This shows that the radiographic anatomy of the distal end radius in children changes with age.

Fig. 5.

Variations of parameters with age

Fig. 6.

Variations of parameters with age

Discussion

Due to the metaphyseal development spurt, “the distal end of the radius is among the most often fractured locations in children aged 8–16 years. These fractures typically occur following a fall onto an extended hand. It is diagnosed by wrist radiographs and is majorly managed by closed reduction and casting [12, 13]. Significantly displaced or angulated fractures in patients who are nearing skeletal maturity need surgery [14]. Despite being a fairly frequent injury (fractures of the distal forearm constitute 35–45% of all pediatric long bone fractures) [15], the distal radius anatomy in the Indian paediatric population has never been studied radiographically.

In adolescents and children, a number of non-traumatic diseases, including congenital abnormalities, may impede the growth as well as development of the distal radius, carpus, and ulna. As normal wrist geometry and development are vital contributing factors to maintaining proper wrist growth and function as well as conducting proper wrist motions, restoring distal end radius parameters in paediatric fractures and non-traumatic diseases affecting the wrist is crucial. Since there is still growth potential left in this age group, restoration of the distal end radius normal anatomy can prevent long-term issues like growth plate disruption, deformities, and impaired wrist function. The steady rise in both the distal radial size and slope with aging is explained by the growth of the radial height and inclination. Loss of radial height is a practical indicator of a worse prognosis in distal radial fractures [16]. Both the paediatric and adult populations basically agree on this [17]. In physeal distal radius fractures, loss of radial height results from either overlap (bayonet apposition) or metaphyseal comminution [16]. Growth will result in an increase in the strain across the lunate due to loss of radial inclination [17].

Three values that are routinely used to ascertain the need for surgery and the acceptability of correction in adults are (1) radial height, (2) radial inclination, and (3) volar tilt. For adults, the average values of these 3 measures are known; however, for the Indian paediatric population, they are not. Our study identified the normal range of three radiographic parameters—(1) Radial height, (2) Radial inclination, and (3) Volar tilt” in the Indian paediatric population aged 8–16 years on Postero-anterior and Lateral view of the wrist radiograph. Less bone overlap may be seen in the Postero-anterior view, making it simpler to calculate these parameters. Also, two different studies: One by Johnson [16] and another by Pennock et al. [17] demonstrate that the apparent morphometric measures at the distal end of the radius are considerably increased when the forearm is supinated.

Our study has its limitations. Children have significant cartilaginous epiphyseal components periarticularly which makes them very different from adults. Only the ossified anatomy that is evident on simple radiographs has been the subject of our investigation. MR imaging is not cost-effective, despite the fact that it would have increased visibility of this cartilaginous component. Hence it becomes impractical as the study includes a large volume of patients. Another limitation of the study is the lack of ethnicity of the subjects. The study was performed at a large teaching hospital in Mumbai. Although the ethnicity of each patient was not noted for this study, results of the latest census done in 2011 [19] reveal that in the state of Maharashtra, particularly Mumbai, the population consisted of 60.7% Hindu, 25.1% Muslims, 5.4% Jain. 0.49% Sikhs, 4.4% Buddhist, 2.7% Christians 0.40% Sikh. Based on the population, we expect our study results to mostly represent normal values in Hindu population.

The difference between our study and the Western literature is compared in Table 4. In our study, the range of distal end radial inclination is 15°–25° which is in the reference range of Hosseinzadeh and Olson [1], 2018 (19.66°–24.79°) and of Sallam et al. [18], 2020 (10.5°–33.5°). The range of volar tilt in our study is 4°–15° and the lower/upper limit does not fall in the reference range of volar tilt in a study by Hosseinzadeh and Olson [1], 2018 (9.96°–13.57°) but it falls in the reference range of Sallam et al. [18] (0°–16°). The range of distal end radial height in our study is 9.0–14.50 mm which is not significantly different from the reference range of Hosseinzadeh and Olson [1], 2018 (8.73–14.01 mm). It also falls in the reference range of Sallam et al. [18], 2020 (6.6–15.4 mm). Our findings may be utilized therapeutically to create a template of normal values that doctors treating children with fractures and wrist pathologies may utilize as a reference.

Table 4.

Comparison of our study to western literature on the paediatric population

	Our study (n = 130) Age: 8–16 indian population	Hosseinzadeh P and Olson D1, 2018 (n = 372) Age: 8–16 Caucasians	Sallam AA, Briffa N12, 2020 (n = 896)
Radial inclination	15.0–25.0	19.66–24.79	10.5–33.5
Volar tilt	4.0–15.0	9.96–13.57	0–16
Radial height	9.0–14.50	8.73–14.01	6.6–15.4

Conclusion

In true Postero-anterior and lateral wrist radiographs of the Indian paediatric population, we have established normal values that may be utilized as a guide for the evaluation and treatment of a variety of traumatic and non-traumatic problems in Indian children.

Funding

None.

Data availability

The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable requests.

Declarations

Conflict of Interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.

Informed Consent

Informed consent was obtained from all individual participants included in the study.

Ethical Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (Institutional Ethics Committee Human research, LTMMC AND GH, SION + Ref: IEC/42/43) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.