Abstract: Relevance. Significant incidence of hip pathology in different groups of patients with cerebral palsy and factors that may

affect its formation are relevant objects of the study.

The goal of the study. To establish the features of the hip joint’s formation, examining the clinical and radiographic dependences

of the functional status and indices of the hip joint in patients with cerebral palsy.

Materials and methods. The total number of patients was 47 persons (86 joints). We conducted a clinical and radiographic

examination of the hip joints using our own methods and standard anterior-posterior radiography, as well as a statistical analysis

true parameters of the femoral neck–shaft angle and torsion of the femur.

Keywords: cerebral palsy, hip joint, radiogrammetrical indices, Reimers’ index, Wiberg angle.

Received: April 11, 2022. Revised: August 4, 2022. Accepted: September 8, 2022. Published: October 10, 2022.

1. Introduction

Pediatric orthopedists pay special attention to the determination

of instability in the hip joint (HJ) in patients with cerebral palsy

therapeutic decisions [1]. Imbalance of muscle activity, as well

as bone and joint pathology leads to decentralization of the

femoral head and the progression of instability in the HJ.

The mentioned above features encourage researchers to look

for factors underlying the pathogenesis of spastic femoral head

(FH) dislocation to detect pathological changes in HJ among

patients with cerebral palsy in a timely manner to move from

conservative to surgical treatment.

Modern radiological systems for HJ screening in patients

with cerebral palsy are focused on ascertaining the fact of

yield researchers the precise parameters of this joint. Accurate

parameters of the HJ make it possible to select patients, assess

the quality of surgery and are the key to successful surgical

interventions aimed at stabilizing the hip joint in cerebral palsy

[2]. We have developed our own method for determining the

clinical and radiographic parameters of HJ [3], that has been

used in the examination of patients with cerebral palsy.

The obtained true parameters of the HJ prompted us to a more

detailed study of the dependencies that may have an impact on

the formation of instability in this joint referring to age norms.

indices of the hip joint and femur migration in patients with

cerebral palsy

Our research is based upon the study of clinical cases of 47

patients (86 joints) with pathology of the hip joints in cerebral

palsy who have been treated in the Institute of Traumatology

and Orthopedics of the National Academy of Medical Sciences

of Ukraine during 2018-2020. The gender of the patient was not

taken into account, as previous studies did not report significant

differences between the sexes [4]. No patient had a history of

bone surgery. We investigated various factors that may

influence the formation of parameters responsible for the

relationship between the proximal femur and the acetabulum,

dependences of the influence of the proximal femur (PF)

pathology (neck-shaft angle (NSA), femoral torsion (FT),

acetabular angle (AA) and Sharp’s angle (SA)) upon WA and

RI. The age of patients ranged between 3 and 30 years: up to 4

years (5 patients), 4-6 years (10 patients), 7-9 years (10

patients), 10-12 years (8 patients), 13-16 years (13 patients), 30

years (1 patient). According to the GMFCS II level was

observed in 11 patients, III level in 16 patients, IV level in 12

patients. The sample in this study consisted mainly of patients

with spastic tetraparesis (30 patients), spastic paraparesis (9

spastic hip dislocation. AM was performed in 8 patients. Hip

radiographs (performed at the age 3 months) were preserved in

15 patients: 8 patients were diagnosed with DDH, 7 patients

were born with healthy hips. Data on whether DDH was treated

before the age 1 year were not taken into account due to their

absence.

In order to avoid exposure of healthy children, the normal

indices were taken from Kutsenok Ya.B. (Table 1) [6]. The

Reimers index up to 33% was considered as a stable joint,

subluxation (more than 33%) as a pathology.

In this study, we used the true parameters of NSA and FT

obtained from positioning using our original method [9], and all

the rest from both positionings.

In the study, the results of the analysis are presented in the

form of distributions of clinical parameters (in %), arithmetic

mean and standard deviation (M ± SD). Comparisons between

acetabular angle, Sharp’s angle) to demonstrate how the former

In comparison with groups of patients by age in SP in 8 joints

M=35.6±4.8 was within normal limits, in 71 joints (91.03%)

M=14.6±16.3 and there was a WA decrease. There was a

statistically significant increase in the frequency of detection of

reduced WA in SP depending on the increase of GMFCS levels

(p<0.05, p=0,003). In normal WA (p>0.05, p=0.55) the

difference between groups was statistically insignificant, and in

the increase GMFCS level (p<0.05, p=0.01). With normal WA

in PATOOM (p>0.05, p=0.47) the difference between the

groups was statistically insignificant, with a decrease in the

angle (p<0.05, p=0.0039) there were significant inter-group

differences. In comparison with groups of patients according to

GMFCS (II, III, IV levels) in SP in 47 joints (59.49%) the RI

average M=16.7±6.6 was within normal limits, in 32 joints

(40.51%) M=50.2±17.2 and there was an RI increase. There

was a statistically significant increase in the frequency of

detection of increased RI in PATOOM depending on the

difference was statistically insignificant. In PATOOM in 61

joints (70.93%) RI average M=18.3±7.1 was within normal

limits, in 25 joints (29.07%) M=45.5±16.0 and there was a RI

increase. There was a statistically significant increase in the

frequency of increased RI detection in PATOOM depending on

the separated group (p<0.05, p=0.015). In non-increased RI

(90.59%) M=14.6±16.3 and there was a decrease of WA. There

were statistically significant differences in WA in SP by groups

(p<0.05, p=0.043). When observing reduced WA (p<0.05,

p=0.0009), significant differences were observed between

groups. WA in PATOOM in 6 joints (7.06%) average values

M=35.8±5.2 were within the normal, in 79 joints (92.94%)

M=17.2±12.1 and there was a WA decrease. Statistically

insignificant differences in WA in PATOOM by groups

(p<0.05, p=0.083) were found. Significant differences between

groups were observed in a WA decrease (p<0.05, p=0.001). In

There were statistically significant differences in RI in the SP

by groups (p<0.05, p=0.018). In non-increased RI (p>0.05,

p=0.79) and in its increase (p>0.05, p=0.98) the difference

between the groups was statistically insignificant. In PATOOM

in 61 joints (70.93%) RI average M=18.3±7.1 was within

normal limits, in 25 joints (29.07%) M=45.5±16.0 and there

on DDH (DDH, healthy joints at birth) in SP in 2 joints (7.41%)

the WA average M=35.6±4.8 was within normal limits, in 25

joints (92.59%) M=14.6±16.3 and there was a WA decrease.

Statistically insignificant differences of WA in SP by groups

(p<0.05, p=0.10) were found. In normal WA (p>0.05, p=0.29)

and in its reduction (p>0.05, p=0.23) the difference between the

groups was statistically insignificant. WA in PATOOM in 1

joint (3.70%) average values M=35.8±5.2 were within the

normal, in 26 joints (96.30%) M=17.2±12.1 and there was a

WA decrease. Statistically insignificant differences of WA in

significant, medium-strength, inverse correlation was found

between NSA and WA in PATOOM (R=-0.3582, p<0.05).

In normal FT the frequency of pathological WA detection in

SP was 2 (66,67%) cases, in increase of FT in statistically

insignificant way (p>0.05, p=0.14) the frequency of

pathological WA detection increases in 75 cases (91.46%).

(93.90%). Using Pearson correlation method, a significant,

medium-strength, inverse correlation was found between FT

and WA in PATOOM (R=-0.3125, p<0.05).

Using Pearson correlation method, a reliable, strong, direct

correlation was found between the AA measured in both

PATOOM, the frequency of pathological WA detection in SP

was 33 (82.50%) cases, with increasing of AA in statistically

significant way (p<0.05, p=0.01) increases the frequency of

pathological WA in 44 (97.78%) cases. Using Pearson

Using Pearson correlation method, a reliable, medium-strength,

direct correlation between NSA and RI in SP (R=0.4131,

p<0.05) was detected. In the PATOOM and normal NSA, the

frequency of pathological RI detection was 1 (3.57%) cases,

with increasing of NSA in statistically significant way (p<0.05,

p=0.000) increases the frequency of pathological RI detection

pathological RI detection in 33 (39.76%) cases. Using Pearson

correlation method, a reliable, medium-strength, direct

correlation between FT and RI in SP was found (R=0.3916,

p<0.05). In the PATOOM with normal FT, the frequency of

pathological RI detection was 0 (0.0%), with an increase of FT

in statistically insignificant way (p>0.05, p=0.25) increases the

frequency of pathological RI detection in 25 (30.12%) cases

(Fig. 3). Using Pearson correlation method, a reliable, medium-

strength, direct correlation between FT and RI was found in the

PATOOM (R=0.3304, p<0.05).

statistically significant way (p<0.05, p=0.03) increases the

frequency of increased NSA detection in 35 (77.78%) cases

(Fig. 6). Using Pearson correlation method, reliable, medium-

strength, direct correlations between AA and NSA in SP

(R=0.6072, p<0.05) and in the PATOOM (R=0.3888, p<0.05)

were revealed.

and in the PATOOM (R=0.3703, p<0.05) were revealed.

In normal AA the frequency of pathological FT detection was

38 (92.68%) cases, in increase of AK in statistically

insignificant way (p>0.05, p=0.06) the frequency of detection

of the increased FT in 45 (100.0%) cases increases as well (Fig.

7). Using Pearson correlation method, reliable, weak, direct

correlations between AA and FT in SP (R=0.2409, p<0.05) and

in the PATOOM (R=0.2640, p<0.05) were revealed.

In normal SA the frequency of pathological FT detection was

30 (96.77%) cases, in increase of SA in statistically

in the form of review articles and in the form of case studies.

cerebral palsy, but performed examinations of the hip joints of

Medical Sciences of Ukraine. Most patients did not ambulate

promising in terms of verticalization. The older age groups

No relationship was found between WA in both positionings

relationship between the proximal femur and the acetabulum

spastic FH dislocation occurs, the ambulation function is lost.

Analyzing WA in both positionings among patients with

cerebral palsy who had an AM in their medical history and

patients who did not have it, we did not find a statistically

significant inter-group difference. The dependences between

the RI and the studied groups in the SP and the absence of

among patients with cerebral palsy after this operation. Only

clinical indications for AM are used, often without taking into

account the bone pathology of the hip joint. Our studies show

that AM does not affect WA (the relationship between PF and

the acetabulum) in patients with cerebral palsy, and there are

some dependences on the effect upon RI (stability index) in

standart positioning.

We did not find statistically significant differences when

analyzing WA in both positionings in the groups of patients

with DDH and patients born with healthy hip joints confirmed

dislocation.

Significant, medium-strength, inverse correlations between

FT and WA in both positionings and reliable, medium-strength,

direct correlations between FT and RI in both positionings were

found. At the same time, with increasing FT, the frequency of

pathological WA and RI detection in both positionings

non-ambulating patients with cerebral palsy compensate

pathological FT by internal rotation of the thighs, thus

minimizing its impact upon the acetabulum, but this position

contributes to the most common posterolateral spastic FH

dislocation.

A reliable, strong, inverse correlation between AA and WA

in both positionings and a reliable, medium, direct correlation

between AA and RI in both positionings were found. With

increasing AA in statistically significant way increases the

frequency of of pathological WA detection in SP, and slightly

placement of the patellas. In the 1980's it was believed that the

knee joint when ambulating should work in the sagittal plane,

thus the author chose this positioning. Although the author did

not deny the measurement of RI in other positionings and noted

the minimum percentage of error [14].

The Reimers’ index showed greater reliability compared to

cerebral palsy. PATOOM can be used to screen the hip joints in

significant effect upon the acetabular parameters in the frontal

plane, but there were significant, moderate, inverse correlations

between FT and WA and direct correlations between FT and

RI.

preparation of this article.

Fig. 4 The association between the detection of the normal and pathological acetabular angle (AA) and Reimers’ index (RI) in the standard

positioning (SP) and positioning according to our own method (PATOOM).