The thickness of the sternocleidomastoid muscle as a prognostic factor for congenital muscular torticollis

Congenital Muscular Torticollis-Current Understanding and Perinatal Risk Factors: A Retrospective Analysis

INTRODUCTION

Congenital muscular torticollis (CMT) is an asymmetrical head position resulting from structural changes in the sternocleidomastoid (SCM) muscle that occurs early during a child's development or due to perinatal trauma. Children with CMT exhibit a marked imbalance in tension between the SCMs. In a typical clinical picture, an ultrasound scan is performed to reveal characteristic lesions, such as tissue fibrosis or post-traumatic changes. An early diagnosis of CMT in newborns and the implementation of treatment offer the chance of a complete resolution. Torticollis treatment aims to restore the SCM's normal function. Surgical treatment is performed when conservative methods fail to improve the patient's condition. The indications that surgery is needed include a marked shortening of the SCM, persistent fibrosis in the muscle, constant head and facial asymmetry, and rotation or lateral flexion in the cervical spine restricted by >15°. Of all the newborn and infant anomalies, congenital torticollis is the third most common after hip dysplasia and equinovarus deformities. Some authors demonstrate that torticollis coexists with hip dysplasia.

AIM

The aim of this study was to collect data on infants referred to paediatric rehabilitation and to identify the risk factors associated with CMT in this group of patients, as well as to assess demographic and clinical characteristics concerning risk factors.

MATERIALS AND METHODS

The target population for this retrospective study consisted of 111 infants aged 0 to 5 months born in Poland and diagnosed with and undergoing treatment due to CMT. The following were determined: the relationship between the side of the CMT location and the type of delivery (caesarean section vs. vaginal), the relationship between the body weight at birth and the side of the CMT location, the relationship between the extent of SCM thickening and the type of delivery, and the incidence of CMT depending on the order of delivery.

RESULTS AND CONCLUSIONS

The data revealed that CMT is less common in female infants (n = 51, 46%) compared to male (n = 61, 54%) infants, in whom a greater birth weight was reported (p < 005). Seventy-six percent (76%) of the paediatric patients with CMT were the offspring of primipara mothers. More often, children born via vaginal delivery had left-sided torticollis with a more significant broadening of the SCM, as shown on ultrasound scans, than right-sided torticollis. Theories of torticollis development pathophysiology should be deepened and systematised, and further research is needed.

Experience with the management of 2599 cases of congenital muscular torticollis and a multicenter epidemiological investigation in 17 hospitals in China

BACKGROUND

Congenital muscular torticollis (CMT) is a common musculoskeletal disease affecting infants and young children. If CMT is not treated correctly and timely, it can lead to limited head and neck movements, head and neck deviation, and abnormal posture. In order to improve patients' symptoms and alleviate the negative impact of the disease on their lives, we are committed to exploring the treatment of CMT.

METHODS

The general clinical and ultrasonographic data of 2599 children with CMT who received standardized treatment at Shenzhen Children's Hospital from 2004 to 2020 were retrospectively reviewed. According to given treatment, children with CMT were divided into the physiotherapy group, physiotherapy combined with glucocorticoid treatment group, and surgical treatment group. We divided children with CMT into local mass, uniform thickening, and atrophy according to ultrasound features. General clinical information, treatment, and ultrasound examination data in each group were compared. Additionally, electronic medical records of 2344 patients admitted due to CMT in 17 tertiary children's hospitals of China's Futang Research Center of Pediatric Development (FRCPD) from 2015 to 2019 were retrospectively analyzed. Data on sex, age, year of admission and discharge, and treatment costs during hospitalization were extracted from the first medical record pages according to the ICD codes. The data were assessed for normality using the Kolmogorov-Smirnov test. Depending on the data distribution, they were analyzed using parametric tests, such as the t-test, or non-parametric tests. Qualitative data are expressed as percentages (%) and analyzed using the chi-square or Fisher's exact probability test, with α = 0.05 as the test level. P < 0.05 was considered to be indicative of a statistically significant difference.

RESULTS

Three types of CMT were defined based on sternocleidomastoid muscle ultrasound examination characteristics: local mass, uniform thickening, and atrophy. Age at first diagnosis was 69.21 ± 108.41 days in local mass type group, 216.85 ± 324.09 days in uniform thickening group, and 417.88 ± 739.05 days in atrophy- type group; while age at first physiotherapy use was 94.06 ± 206.49 days, 255.00 ± 430.62 days, 540.92 ± 1059.29 respectively. The children included in local mass type group have shown a high success rate of conservative treatment, with a rate of 7.5% of children underwent surgery. Age at first diagnosis was 112.44 ± 224.12 days in the physiotherapy group, 115.87 ± 144.86 days in the physiotherapy combined with glucocorticoid treatment subgroup, whereas the age at first physiotherapy use was 137.38 ± 312.11 and 196.91 ± 344.26 days respectively. In the observation period (2015-2019) the mean age at surgery for CMT in 17 tertiary children's hospitals of the FRCPD was 50 months. Overall, 663 children with CMT were 1-2 years of age, accounting for the largest proportion (28.3%). Followed by 417 individuals (17.8%) were 7-14 years of age, indicating that there are still more children with CMT receiving surgical treatment later.

CONCLUSIONS

Early diagnosis and treatment are essential to improve the conservative treatment success rate and achieve good prognosis in children with CMT. Our team's concept for treating CMT is as follows: after diagnosing the children, we will adopt the standardized protocol of treatment, with physiotherapy combined with the injection of glucocorticoid drugs and SCM release surgery, when needed. This program has a high conservative treatment success rate and may facilitate the achievement of better prognosis and reduced teratogenicity rate.

The Effectiveness and Safety of Botulinum Toxin Injections for the Treatment of Congenital Muscular Torticollis

OBJECTIVE

Botulinum toxin have been used to treat congenital muscular torticollis for the last 25 years; however, few studies have been published with only limited cases and short-term follow-up. The aim of the present study is to systematically review the effectiveness and safety of botulinum toxin injections for congenital muscular torticollis by analyzing these relevant literatures.

METHODS

The authors searched PubMed, Web of Science, EMBASE, Cochrane Library, China Biology Medicine, for all articles about botulinum toxin injections for the congenital muscular torticollis. The MINORS evaluation tool was adopted to evaluate the quality of these studies. Meta-analysis calculations are made by R software 3.6.2.

RESULTS

This study search involved strict inclusion criteria and targeted data collection. Ten studies were included, with a total of 411 patients, comprising 1 non-randomized experimental study and 9 cases or case series. The results of our meta-analysis of single rate showed that the overall effective rate of botulinum toxin for congenital muscular torticollis was 84% (95% confidence interval [CI] 67%-96%). After botulinum toxin treatment, the conversion rate to surgery was 9% (95% CI 4%-22%), and the adverse reaction rate was 1% (95% CI 0%-3%). The most common adverse reactions among these included studies involve injection site erythema and transient dysphagia.

CONCLUSION

Current evidence shows that botulinum toxin injections for the treatment of congenital muscular torticollis is safe and effective, with few serious adverse reactions. Further well-designed, larger randomized trials are warranted.

Correlations between the Clinical and Ultrasonographic Parameters of Congenital Muscular Torticollis without a Sternocleidomastoid Mass

Objective

To determine whether ultrasonography at initial presentation can help assess the clinical severity of congenital muscular torticollis (CMT) in infants without a sternocleidomastoid muscle (SCM) mass.

Materials and Methods

This retrospective study included 71 infants aged less than 12 months (4.1 ± 2.3 months) with non-mass CMT. The clinical severity was divided into three grades (groups 1–3) based on the degree of lateral head bending or cervical rotation. The difference (SCM-D) and ratio (SCM-R) between the maximal thickness of the affected and non-affected SCMs were obtained using transverse and longitudinal ultrasonography. The sonographic echotexture and echogenicity of the involved SCM were reviewed.

Results

A significant difference was observed in the SCM-D (0.42 ± 0.30 mm in group 1; 0.74 ± 0.50 mm in group 2; 1.14 ± 0.85 mm in group 3; p = 0.002) and SCM-R (1.069 ± 0.067 in group 1; 1.129 ± 0.087 in group 2; 1.204 ± 0.150 in group 3; p = 0.001) among the groups when measured along the longitudinal but not along the transverse ultrasonography plane. The areas under the curves of the SCM-R and SCM-D measured by longitudinal ultrasonography were 0.731 (p < 0.001) and 0.731 (p < 0.001) for group 1 versus groups 2–3. The proportions of heterogeneous echotexture or hyperechogenicity in the involved SCM did not differ significantly among the three clinical groups (all p > 0.05).

Conclusion

Ultrasonography can aid in assessing the clinical severity of CMT in infants without an SCM mass at the time of initial diagnosis. The SCM-R and SCM-D helped grade the clinical severity when obtained by longitudinal scan.

Clinical Usefulness of Sonoelastography in Infants With Congenital Muscular Torticollis

Objective

To evaluate the clinical usefulness of sonoelastography in infants with congenital muscular torticollis (CMT).

Methods

The medical records of 215 infants clinically diagnosed with CMT were retrospectively reviewed. Fifty-three infants met the inclusion criteria as follows: 1) infants diagnosed as CMT with a palpable neck mass before 3 months of age, 2) infants who were evaluated initially by both B-mode ultrasonography and sonoelastography, and 3) infants who had received physical therapy after being diagnosed with CMT. We checked the thickness of the sternocleidomastoid (SCM) muscles in B-mode ultrasonography, strain ratio of the SCM muscles in sonoelastography, and treatment duration. We evaluated the correlation between the treatment duration and the following factors: SCM muscle thickness, ratio of SCM muscle thickness on the affected to unaffected side (A/U ratio), and strain ratio.

Results

Both the thickness of the affected SCM muscle and the A/U ratio did not show significant correlation with the treatment duration (p=0.66, p=0.90). The strain ratio of the affected SCM muscle was significantly greater than that of the unaffected SCM muscle (p<0.001), and the strain ratio showed significant correlation with the treatment duration (p=0.001).

Conclusion

Sonoelastography may be a useful adjunctive tool to B-mode ultrasonography for evaluating infants with CMT, especially when predicting their rehabilitation outcomes.

Quantitative analysis of magnetic resonance imaging of the neck and its usefulness in management of congenital muscular torticollis

Objective

To quantify magnetic resonance imaging (MRI) findings of congenital muscular torticollis (CMT) and to demonstrate the usefulness of quantitative MRI findings in the management of CMT.

Methods

This was a retrospective study of 160 subjects with CMT who had undergone neck MRI at the age of 48 months or younger at a tertiary medical center. Among the 160 subjects, 54 had undergone surgical release of CMT and 106 subjects had not undergone surgery. For the quantitative analysis, the ratios of area and intensity of the MRI findings were measured and compared between the two groups (ratio of area = the largest cross-sectional area of the SCM with CMT - the cross-sectional area of the contralateral SCM without CMT / the cross-sectional area of the contralateral SCM without CMT; ratio of intensity = the mean gray color intensity of the contralateral SCM without CMT - the lowest mean gray color intensity of the SCM with CMT / the mean gray color intensity of the contralateral SCM without CMT). Receiver operating characteristic (ROC) curve analysis was conducted for the ratios of area and intensity in order to find the optimal cutoff value for determining the need for surgery in CMT cases.

Results

The ratios of area and intensity were significantly higher in the surgical group than in the non-surgical group (p≤0.001), suggesting that the sternocleidomastoid muscle (SCM) was thicker and darker in the surgical group than in the non-surgical group. The optimal cutoff value for the ratio of area was 0.17 and that for the ratio of intensity was 0.05. All subjects with a ratio of intensity less than 0.03 belonged to the non-surgical group, and all subjects with a ratio of intensity greater than 0.16 were categorized in the surgical group.

Conclusion

The quantitative MRI findings, i.e., ratios of area and intensity, may provide a guideline for deciding the need for surgical intervention in CMT patients. Further prospective studies are required to verify these findings.

Factors that affect the rehabilitation duration in patients with congenital muscular torticollis

OBJECTIVE

To determine which factors affect the rehabilitation duration in patients with congenital muscular torticollis (CMT) and to predict the duration of rehabilitation and prognosis.

METHODS

One hundred and eighteen patients (79 males and 39 females) who were diagnosed with CMT and received physical therapy were enrolled in this study. We retrospectively reviewed the information in terms of sex, gestational age, birth weight, methods of delivery, fetal presentation, age at diagnosis, the affected sternocleidomastoid (SCM) muscle site, SCM muscle thickness, ratio of muscle thickness on the affected side to that on the unaffected side (called the 'abnormal/normal [A/N] ratio'), and range of motion for cervical rotation and side bending.

RESULTS

The SCM muscle thickness and A/N ratio had a positive linear relationship with the rehabilitation duration. Patients who were in the breech position needed longer rehabilitation. The birth weight and age at diagnosis were negatively correlated with the rehabilitation duration. However, the cervical range of motion, mass site, sex, gestational age, and methods of delivery were not correlated with the rehabilitation duration.

CONCLUSION

Patients with a thicker SCM, lower birth weight, and history of breech delivery had a longer rehabilitation duration.