Abstract
Background: The natural history of congenital
muscular torticollis and the outcome of different treatment modalities
have been poorly investigated, and the results of treatment have
varied considerably.
Methods: The main objective of this prospective
study was to evaluate the outcomes of 821 consecutive patients with
congenital muscular torticollis who were first seen when they were
less than one year old, were treated with a standardized program
of manual stretching, and were followed for a mean of 4.5 years.
Before treatment, the patients were classified into one of three
clinical groups: (1) palpable sternomastoid tumor, (2) muscular
torticollis (thickening and tightness of the sternocleidomastoid muscle),
and (3) postural torticollis (torticollis but no tightness or tumor).
Results: Of the 821 patients, 452 (55%)
had a sternomastoid tumor; 276 (34%), muscular torticollis;
and ninety-three (11%), postural torticollis. Multivariate
analysis of the outcomes showed that (1) the duration of treatment
was significantly associated with the clinical group (p < 0.0001),
a passive rotation deficit of the neck (p < 0.0001), involvement
of the right side (p < 0.0001), difficulties with the birth
(p < 0.009), and age at presentation (p < 0.0001);
(2) the overall final assessment score was associated with the rotation
deficit (p = 0.02), age at presentation (p = 0.014),
and duration of treatment (p < 0.0001); and (3) subsequent
surgical treatment was required by 8% (thirty-four) of
the 452 patients in the sternomastoid tumor group compared with 3% (eight)
of the 276 patients in the muscular torticollis group and 0% (none)
of the ninety-three patients in the postural torticollis group.
Conclusions: This large prospective study demonstrated
that controlled manual stretching is safe and effective in the treatment
of congenital muscular torticollis when a patient is seen before
the age of one year. The most important factors that predict the
outcome of manual stretching are the clinical group, the initial
deficit in rotation of the neck, and the age of the patient at presentation.
Surgical treatment is indicated when a patient has undergone at
least six months of controlled manual stretching and has residual
head tilt, deficits of passive rotation and lateral bending of the
neck of >15°, a tight muscular band or tumor, and a poor
outcome according to our special assessment chart.
The reported prevalence of congenital muscular torticollis
has ranged from 0.3% (fifteen of 5079 live births) to 2.0% (forty-three
of 2190 live births)1-7. The typical
lesion is a hard mass within the substance of a tight sternocleidomastoid
muscle. It is often recognized when a child is one to four weeks old.
The size of the lesion ranges from 1 to 3 cm in its largest transverse
diameter. It is firm and smooth, movable beneath the skin, and apparently tender
to touch8. After reaching its
maximum size, the mass gradually recedes at varying rates within
the first year and, in most patients, the muscle tightness subsides after
the mass has resolved. In some patients, large portions of the muscle
may become fibrotic. Secondary or associated skull and facial asymmetry
or plagiocephaly are often found.
Macdonald9 divided patients
with congenital muscular torticollis into two groups: those with
a sternomastoid tumor and those with tightness of the sternocleidomastoid
but no clinical tumor, which he termed muscular torticollis. Postural
torticollis is a term used to describe patients with congenital
torticollis who have all the clinical features of torticollis but with
no demonstrable tightness or tumor of the muscle10.
However, a clear distinction has not been made between postural
torticollis and congenital muscular torticollis in the literature,
and in most series the term congenital muscular torticollis includes
all three groups. To facilitate comparison with other series in
the literature, we adopted these three terms (sternomastoid tumor,
muscular torticollis, and postural torticollis) for our study.
Reports of the natural history and the outcome of treatment have
varied considerably4,9-13. A common
observation is that 54% (twenty-two of forty-one) to 70% (194
of 277) of the sternomastoid tumors resolve within the first year
after birth9,11. Some patients
have a degree of residual fibrosis of the muscle without an obvious
clinical problem, and others (9% [six of sixty-six] to
21% [eighteen of eighty-four]) have progression
to frank muscular torticollis and clinical deformity that requires
surgical intervention4,9,10,13.
Infants seen initially with muscular torticollis have an outcome
similar to that in infants with a sternomastoid tumor4.
Although it is well accepted that late cases of torticollis with
a definite tight muscular band should be treated operatively,
there is no clear consensus on the management of early cases. Treatment
recommendations include observation only14,
application of an orthosis11,15,
an active home program of stimulation exercise and positioning1,11,15, gentle manual stretching1,4,11,14-17, vigorous manual manipulation
with rupturing of the tight sternocleidomastoid muscle10, and various types of operative
procedures2,4,8,18,19.
Despite the controversies, manual stretching is still the most
common treatment for both sternomastoid tumor and muscular torticollis2,10-12,14-18,20,21. Success rates
have ranged from 61% (nineteen of thirty-one)14 to 99% (ninety-nine of
100)15. However, most of the studies
have been retrospective, they often have consisted of small numbers
of patients with a wide age-range, and data often have been collected
over a long period of time. The type of congenital muscular torticollis
has rarely been defined, the severity of disease prior to treatment has
not been clear, the protocol and details of the stretching program
have not been standardized, and no standard assessment methods have
been used to compare the patients before and after treatment.
The main objective of the present prospective longitudinal study
was to evaluate, according to a standard clinical classification
system and assessment method, the effect of a standardized manual
stretching program on a large group of patients with clearly defined
congenital muscular torticollis. Another objective was to evaluate
the factors that predict the outcome of treatment.
A total of 1086 patients with congenital muscular torticollis
were first seen at birth or before the age of one year at our special
Torticollis Clinic between 1985 and 1997. Of those patients, 821
were treated with a manual stretching program and were included
in the study.
During the same period, 237 other patients who were seen in the
Torticollis Clinic were not included in this study. Of those patients,
117 who had congenital muscular torticollis presented after the
age of one year and another 120 patients had another type of torticollis
such as acute torticollis, congenital anomalies of the cervical
spine, spasmodic torticollis, obvious ocular torticollis, or another
form of neurogenic or organic torticollis.
The information recorded for all patients seen in the clinic
included gender, age at presentation, side of the torticollis, birth
history and obstetrical data (breech presentation, vacuum extraction,
forceps delivery, or caesarean section), and evidence of hip dysplasia
and any other associated congenital anomalies.
Clinical Classification of Congenital Muscular
Torticollis
All of the patients with congenital muscular torticollis were
placed into one of the following three clinical groups4,9,10: (1) sternomastoid tumor group
(those with a clinically palpable sternomastoid tumor), (2) muscular torticollis
group (those with clinical thickening and tightness of the sternocleidomastoid
muscle), and (3) postural torticollis group (those with postural head
tilt and clinical features of torticollis but without tightness
or tumor of the sternocleidomastoid muscle).
In the sternomastoid tumor group, the largest transverse diameter
of the mass was measured to the nearest 0.5 cm. The distribution
of the mass within the muscle was described as cephalad, middle,
or caudad third or whole muscle-length involvement.
Subgroups According to Limitation of Passive Range
of Rotation of the Neck
The range of rotation of the neck was measured with a specially
designed arthrodial protractor. The infant’s shoulders
were stabilized in the supine position, and the head and neck were
supported by the examiner in the neutral position, with regard to flexion
and extension, over the edge of the examination table. This position
allowed a detailed examination of the whole sternocleidomastoid
muscle and at the same time allowed the neck to be rotated and moved
freely in all directions. Normal infants have a passive range of
rotation of up to 110° to each side. Clinical experience suggests
that, compared with measurement of side-bending, measurement of
rotation has better interexaminer reliability1,11,14-16.
In a pilot study to evaluate the reproducibility of rotation measurements,
we found an interexaminer correlation coefficient of 0.71 (unpublished
data). The passive range of rotation of the neck on the side of
the torticollis was compared with that on the normal side, and limitations
were classified into two subgroups: a rotation deficit of £15°
and a rotation deficit of >15°.
Age-Group
The age at presentation was subdivided into four groups: before
the age of one month, at one to three months, at three to six months,
and at six months to one year.
Treatment Protocol
We used a manual stretching program for all patients with clinical
congenital muscular torticollis who presented with a demonstrable
deficit of passive rotation of the neck of >10. The hot,
humid, and crowded local environment precluded the use of a supportive
collar or orthosis. Patients with a deficit of passive rotation
of <10 were managed with an active home program of stimulation
exercises and positioning that was taught to the parents.
Manual stretching was done three times a week by a properly trained
and experienced physiotherapist who used a standardized program.
Each session consisted of three repetitions of fifteen manual stretches
of the tight muscle with a gentle force sustained for one second
and a rest period of ten seconds in between. The parents were also
taught to carry out a home program of active positioning with specific
instructions that they should not do any passive stretching or manipulation.
Treatment duration was defined as the time between the initial assessment
and the time that full passive rotation of the neck was regained
or when there was no further improvement after more than six months
of treatment.
The indication for surgery was a persistent head tilt, with deficits
of passive rotation and lateral bending of the neck of >15°,
a tight band or tumor in the sternocleidomastoid, and a poor result
according to the special assessment chart (Table I). Surgical
candidates either had not responded or had shown no further improvement
after at least six months of manual stretching. The majority of patients
had a caudad unipolar open release with partial excision of the
clavicular and sternal heads of the sternocleidomastoid. Postoperatively,
after the wound had stabilized, an intensive physiotherapy program
including scar massage, maintenance of full passive motion of the
neck, and active strengthening exercises for a period of three to
four months was prescribed. For patients who had a surgical release
when they were more than two years old, a postoperative multiadjustable
torticollis brace was prescribed for a period of three months, in addition
to the physiotherapy program, to maintain the neck in the corrected
position.
Follow-up Assessment
All patients were followed regularly in the special Torticollis
Clinic; they were seen every two months during treatment and at
regular intervals until the final assessment. The degree of head
tilt, the active and passive range of rotation and lateral bending
of the head, facial asymmetry, the size of the tumor and the time
of disappearance of the tumor, and any complications such as ecchymosis
or fracture of the clavicle were recorded at the time of the visit.
The outcome of treatment was analyzed with reference to the total
duration of the treatment period, the overall score at the final
assessment, and the need for operative treatment. The overall results were
graded according to a scoring system and were designated as excellent,
good, fair, or poor on the basis of both subjective and
objective criteria derived from a number of previous studies (Table I)11,14,15,17,19.
Statistical Analysis
Both univariate and multivariate analysis were used to assess
the data. Univariate analysis included the chi-square or chi-square
exact test, t test, Mann-Whitney test, and Kruskal-Wallis test,
where appropriate. Subgroup analyses were performed if there was
a significant association between the two factors. The corresponding
p values were adjusted by the number of paired comparisons performed.
Multivariate analysis included generalized linear models and logistic
regression with relative risks, and their exact 95% confidence
intervals were calculated. For statistical analysis, the overall
scores were subgrouped into an excellent or good group and a fair
or poor group. Similarly, the rotation groups, consisting of the
patients who had £15 of rotation and those who
had >15, were analyzed separately. The rotation groups
and the clinical groups could not be fitted simultaneously into
the same multivariate analysis; hence, these two variables were
analyzed separately.
Statistical analyses were done with the SPSS for Windows statistical
software (release 8.0; SPSS, Chicago, Illinois), S-PLUS (version
4.3; MathSoft, Seattle, Washington), and StatXact (version 2.05; CYTEL
Software, Cambridge, Massachusetts) computer programs. The level
of significance was set at 5%.
A total of 1086 patients with congenital muscular torticollis
who were less than one year old were seen from 1985 to 1997. Of
those patients, 821 were treated with the manual stretching program and
788 (96%) of them were available for the overall final
evaluation. The mean duration of follow-up was 4.5 years (range,1.5
to 13.0 years).
Clinical Classification
A total of 452 patients (55%) had a sternomastoid tumor,
276 (34%) had muscular torticollis, and ninety-three (11%)
had postural torticollis. Torticollis was found on the left side
in 51% (420) of the patients and on the right side in 49% (401),
with no significant difference between the numbers with right and
left involvement in any of the three clinical groups. The male:female
ratio was 3:2 in all three clinical groups.
Age at Presentation
Of the total of 821 patients, 193 (24%) presented to the
clinic within one month after birth; 363 (44%), from one
to three months; 187 (23%), from three to six months; and
seventy-eight (10%), from six to twelve months (Table II).
One hundred and fifty-five (34%) of the 452 patients
who had a sternomastoid tumor were seen within one month after birth,
and 264 (58%) were seen from one to three months after
birth. Only thirty-four (12%) of the 276 patients with
muscular torticollis presented in the first month, whereas eighty-five
(31%) were first seen from one to three months after birth.
Of the ninety-three patients who had postural torticollis, seventy-five
(81%) presented more than three months after birth. A significant
difference with regard to the age at presentation was detected between
the sternomastoid tumor group and the muscular torticollis group (p < 0.0001),
the sternomastoid tumor group and the postural torticollis group
(p < 0.001), and the muscular torticollis group and the
postural torticollis group (p < 0.003).
The mean age (and standard deviation) at presentation was 44
33 days in the sternomastoid tumor group, 109 74 days in the muscular
torticollis group, and 143 75 days in the postural torticollis group,
indicating that the patients in the sternomastoid tumor group presented
earlier than those in the other two groups (p < 0.001).
Limitation of Range of Rotation of the Neck
A rotation limitation of >15° was more prevalent in the
sternomastoid tumor group (72% [327] of
452 patients) than in the muscular torticollis group (32% [eighty-eight] of
276 patients) (p < 0.0001) or the postural torticollis
group (4% [four] of ninety-three patients)
(p < 0.0001) (Table III).
The 419 patients with a rotation deficit of >15 had a
higher rate of breech presentation (17% [seventy-two],
p < 0.0001) and vacuum extraction (30% [125],
p < 0.0001) than the 402 patients who had a rotation deficit
of £15 (7% [thirty] and 14% [fifty-six],
respectively). Seven (2%) of the 402 patients with a rotation
deficit of £15 had hip dysplasia compared with 7% (thirty)
of the 419 who had a rotation deficit of >15 (p < 0.0002).
The median age at presentation of the patients with a rotation deficit
of >15 (thirty-six days) was earlier than that of the patients
with a rotation deficit of £15 (ninety-five days) (p < 0.0001).
Complications of Manual Stretching
Sudden giving-way or snapping of the sternomastoid was observed
during treatment with manual stretching in 8% (thirty-seven)
of the 452 patients with a sternomastoid tumor. Stepwise logistic regression
revealed that those who had hip dysplasia, left-sided involvement,
a rotation deficit of >15, and were less than one month
old at presentation were at higher risk for this event. Sudden giving-way
was followed by clinical signs of bruising and an increase in the
range of motion of the neck, signifying a possible tear or rupture
of the muscle. On subsequent follow-up examination at a mean of 4.5
years, sudden giving-way did not seem to have resulted in an increased
need for operative treatment (two [5%] of
the thirty-seven patients who had had giving-way had an operation
compared with thirty-two [8%] of the
415 patients who had not had giving-way; p = 1.00). Overall,
the clinical result was good or excellent in thirty-five (95%)
of the thirty-seven patients who had giving-way and in 354 (85%)
of the 415 patients who had not had giving-way (p = 0.291).
Determinants and Predictors of Outcome of Treatment
The outcome of treatment was analyzed with respect to the duration
of treatment, the overall score at the final assessment, and the
necessity for operative treatment.
Duration of Treatment
The median duration of treatment was 3.7 months for the sternomastoid
tumor group, 2.5 months for the muscular torticollis group, and
1.4 months for the postural torticollis group. A significant difference
with respect to duration of treatment was detected between the sternomastoid
tumor group and the muscular torticollis group, the sternomastoid
tumor group and the postural torticollis group, and the muscular
torticollis group and the postural torticollis group (p < 0.0001
for each) (Table III).
The duration of treatment was found, with univariate analysis,
to be significantly associated with the age at presentation, the
clinical group, the initial rotation deficit, breech presentation,
difficulties with the birth, and the side of torticollis (p < 0.05). Thus,
a patient with a sternomastoid tumor of the right side, whose birth
was associated with difficulties, who is seen more than one month
after birth, and who has a rotation deficit of >15 is more likely
to need longer treatment.
Multivariate analysis was performed to identify the most important
determinants or predictors of the duration of treatment. The significant
variables from the univariate analysis were entered into the generalized
linear model analysis to assess the confounding factors
associated with duration of treatment. Logarithm transformation
was applied to make the variable less skewed. The results showed that
the duration of treatment was significantly associated with a rotation
deficit of >15 (p < 0.0001), the clinical group
(p < 0.0001), an age of more than one month at presentation
(p < 0.0001), involvement of the right side (p < 0.0001),
and difficulties with the birth (p < 0.009).
Overall Final Score
Of the 821 patients in our study, 788 (96%) were available
for the overall final evaluation at a mean of 4.5 years (range,
1.5 to 13.0 years). The results were significantly different among
the clinical groups. One percent (one) of the eighty-seven patients
in the postural torticollis group, 6% (sixteen) of the
258 in the muscular torticollis group, and 12% (fifty-four)
of the 443 in the sternomastoid tumor group had a fair or poor result.
A significant difference was detected between the sternomastoid tumor
group and the muscular torticollis group (p = 0.033) and
between the sternomastoid tumor group and the postural torticollis
group (p = 0.006) but not between the muscular torticollis
group and the postural torticollis group (p = 0.249).
With use of univariate analysis, the final overall score was
found to be strongly associated with the clinical group (p = 0.0008),
rotation deficit (p < 0.0001), age at presentation (p < 0.0001),
side of involvement (p = 0.035), and difficulties with
the birth (p < 0.017). Thus, a patient with a sternomastoid
tumor, whose birth was associated with difficulties, who is first
seen more than one month after birth, and who has a rotation deficit
of >15 is more likely to have a worse final overall score
(Table IV).
Multivariate analysis with use of the stepwise logistic regression
analysis showed that worse overall scores were associated with a
rotation deficit of >15 (p = 0.02), an age of
one to three months at the time of presentation (p = 0.014),
and the duration of treatment (p < 0.0001) (Table V). After adjustment,
the side of involvement and the clinical group were not found to
be associated with worse overall scores.
Prediction of the Need for Surgical Treatment
Thirty-four (8%) of the 452 patients who had a sternomastoid
tumor needed an operation compared with eight (3%) of the
276 patients in the muscular torticollis group. None of the patients
who had postural torticollis had surgical treatment (Table III). A significant
difference was detected between the sternomastoid tumor group and
the muscular torticollis group (p = 0.027) and between
the sternomastoid tumor group and the postural torticollis group
(p = 0.006) with respect to the need for an operation.
No significant difference was found between the muscular torticollis
group and the postural torticollis group (p = 0.63).
Univariate analysis showed that the factors significantly associated
with operative treatment were the age at presentation, rotation
deficit, clinical group, lateral bending, craniofacial asymmetry
and head tilt, and overall score (Table VI). Thus, a patient with a sternomastoid
tumor who has craniofacial asymmetry and head tilt, is first seen
more than one month after birth, and has a rotation deformity of >15°
and a poor overall score is more likely to need surgical treatment.
No significant association was found between the side of involvement
and the need for an operation (p = 0.081).
Multivariate analysis with the stepwise logistic regression model
showed that the confounding risk factors for an operation were a
late age at presentation (p = 0.008) and the clinical group
(sternomastoid tumor) (p = 0.023) or a rotation deficit
of > 15 (p < 0.0001) (Table VII).
It is difficult to find reliable reports on the outcome of treatment
of congenital muscular torticollis. McDaniel et al.13, in their comprehensive review of
the findings in patients with a sternomastoid tumor, reported that 30% (eighty-three
of 277) to 46% (nineteen of forty-one)9,11 had
natural progression to simple fibrosis of the sternocleidomastoid
without substantial clinical problems and that the percentage of
patients who had progression to frank torticollis requiring surgical
treatment ranged from 9% (six of sixty-six) to 21% (eighteen
of eight-four)4,9,10,12,13. Hulbert10 was the first to describe clearly
the importance of differentiating postural torticollis from true
sternomastoid tumor and muscular torticollis. The natural history
of postural torticollis is always benign; it resolves within a few
months, and operative treatment is never indicated. Jones12 prospectively studied 100 patients
with congenital muscular torticollis and followed them until they were
twelve years old. Sixty-six had a sternomastoid tumor, and thirty-four
had muscular torticollis. Fifty percent of the patients with a sternomastoid tumor
were found to have no evidence of the disorder at six months of
age, 30% had some residual tightness, and 9% required
operative treatment of the torticollis. Of the thirty-four patients
with muscular torticollis, four (12%) had an operation
and eight (24%) had residual fibrosis.
Emery15 reported on a series
of 100 patients with congenital muscular torticollis who presented
before the age of two years (range, 0.5 to 15.5 months) and were treated
with a defined home protocol of stretching and active positioning
stimulation. A successful end point was considered to be a lateral
bending or rotation deficit of <6. The duration of treatment was
used as the outcome dependent variable. The mean duration of treatment
was 6.9 months for the sternomastoid tumor group and 3.9 months
for the muscular torticollis group. According to multiple regression
analysis, the only significant determinant or predictor of treatment
duration was the severity of restriction of neck rotation at the
beginning of treatment (p = 0.0074). A high attrition rate occurred
in that study, with only 100 of 181 patients available for the final
analysis. Only the duration of treatment was used as an outcome parameter,
and the follow-up period was relatively short. The treatment program
was performed by the parents and not by trained therapists, making
standardization of the technique difficult.
To our knowledge, the present study is the only prospective series
with standardized pretreatment classification of the clinical groups,
validated assessment techniques, and a standard manual stretching
protocol performed by experienced physiotherapists. To identify
the determinants of the outcome of treatment in more detail, three
parameters were measured in this study: the duration of treatment,
the overall clinical result, and the necessity for operative treatment.
The mean duration of treatment was found to be significantly
longer in the sternomastoid tumor group (3.7 months) than in the
muscular torticollis group (2.5 months) (p < 0.0001). Univariate
analysis demonstrated that the clinical group (sternomastoid tumor),
an older age at presentation, difficulties with the birth, involvement
of the right side, and rotation deformity of >15° were
all significantly associated with a longer duration of treatment
(p < 0.05). The clinical group (sternomastoid tumor), age
at presentation, more severe rotation deformity, and duration of
treatment all were predictors of the final score.
The current study is unique in that the necessity for operative
treatment was used as an outcome parameter. All of the patients
had regular follow-up examinations in a special torticollis clinic
with use of a clear assessment protocol. The follow-up rate was 96%.
Only patients with a fair or poor final overall score were treated
operatively. Statistical analysis showed that the most important
predictors of the need for operative treatment were the clinical
group (sternomastoid tumor), the severity of the rotation deformity,
and an older age at presentation. None of the patients in the postural
torticollis group needed surgical intervention, an observation that
is consistent with the findings of Hulbert10,
who demonstrated the importance of recognizing postural torticollis.
The current series of patients had much better overall results
with a lower rate of operative intervention compared with those
in most of the reported series2,4,10-12,14-18,20,21.
If patients with postural torticollis were included in the analysis,
the success rate would have been even higher. Several factors may
explain the high success rate associated with manual stretching
in our series. First, all manual stretching was conducted with use
of a clear protocol by trained physiotherapists rather than by parents.
Second, the majority of our patients were first seen early, in the first
few months of life, and treatment was started relatively early.
The effect of stretching on muscles is not totally understood.
A recent study on surgical specimens of sternomastoid tumor, with
use of detailed electron microscopic and immunohistochemical techniques,
showed that myoblasts exist in the proliferating interstitium of
the tumor and are primarily responsible for the maturation and resolution
of the tumor, possibly by producing normal myofibrils22. Given the right stimulus and a
favorable environment, these myoblasts may be activated and contribute
to the regeneration and repair of the abnormal sternocleidomastoid.
Controlled manual stretching may provide a favorable stimulation
for myogenesis. In contrast, without the right stimulus or in cases
of severe damage, fibroblasts may prevail with resultant progressive
fibrosis, as is typical of late muscular torticollis.
The present study showed that controlled manual stretching is
safe and effective in the treatment of congenital muscular
torticollis in about 95% of patients who are first seen
before the age of one year. The most important factors that predict
the outcome of manual stretching are the clinical group (sternomastoid
tumor, muscular torticollis, or postural torticollis), the initial
deficit in rotation of the neck, and the age at presentation. Surgical
treatment is indicated when a patient has undergone at least six
months of controlled manual stretching and has a residual head tilt,
deficits of passive rotation and lateral bending of the neck of >15°,
a tight band or tumor, and a poor result defined as an overall score
of <6 points according to our special assessment scale.
Cheng JC, and Au AW: Infantile torticollis: a review of 624 cases. J Pediatr Orthop,1994.14: 802-8, 14802
1994
[PubMed]
Coventry MB, and Harris LE: Congenital muscular torticollis in infancy. Some observations
regarding treatment. J Bone Joint Surg Am,1959.41: 815-22, 41815
1959
[PubMed]
Dunn PM: Congenital sternomastoid torticollis: an intrauterine postural
deformity [abstract]. Arch Dis Child,1974.49: 824, 49824
1974
[PubMed]
Ling CM, and Low YS: Sternomastoid tumor and muscular torticollis. Clin Orthop,1972.86: 144-50, 86144
1972
[PubMed]
Ling CMBalanchandran
N. A prospective study of sternomastoid tumour in a closed
community. Proceedings of the 10th Singapore Malaysia Congress of
Medicine; 1975. p 233-6.
Suzuki S; Yamamuro T; and Fujita A: The aetiological relationship between congenital torticollis
and obstetrical paralysis. Int Orthop,1984.8: 175-81, 8175
1984
[PubMed]
Tubby AH. Deformities,
including diseases of the bones and joints. A textbook of orthopaedic
surgery. 2nd ed. London: Macmillan; 1912. p 56.
Chandler FA: Muscular torticollis. J Bone Joint Surg Am,1948.30: 566-9, 30566
1948
Macdonald D: Sternomastoid tumour and muscular torticollis. J Bone Joint Surg Br,1969.51: 432-43, 51432
1969
[PubMed]
Hulbert KF: Congenital torticollis. J Bone Joint Surg Br,1950.32: 50-9, 3250
1950
Binder H; Eng GD; Gaiser JF; and Koch B: Congenital muscular torticollis: results of conservative
management with long-term follow-up in 85 cases. Arch Phys Med Rehabil,1987.68: 222-5, 68222
1987
[PubMed]
Jones PG. Torticollis
in infancy and childhood. Sternomastoid fibrosis and the sternomastoid "tumour." Springfield,
IL: Charles C Thomas; 1968. p 3-16.
McDaniel A; Hirsch BE; Kornblut AD; and Armbrustmacher VM: Torticollis in infancy and adolescence. Ear Nose Throat J,1984.63: 478-87, 63478
1984
[PubMed]
Canale ST; Griffin DW; and Hubbard CN: Congenital muscular torticollis: a long-term follow-up. J Bone Joint Surg Am,1982.64: 810-6, 64810
1982
[PubMed]
Emery C: The determinants of treatment duration for congenital
muscular torticollis. Phys Ther,1994.74: 921-9, 74921
1994
[PubMed]
Leung YK, and Leung PC: The efficacy of manipulative treatment for sternomastoid
tumours. J Bone Joint Surg Br,1987.69: 473-8, 69473
1987
[PubMed]
Morrison DL, and MacEwen D: Congenital muscular torticollis: observations regarding
clinical findings, associated conditions, and results of treatment. J Pediatr Orthop,1982.2: 500-5, 2500
1982
[PubMed]
Ferkel RD; Westin GW; Dawson EG; and Oppenheim WL: Muscular torticollis. A modified surgical approach. J Bone Joint Surg Am,1983.65: 894-900, 65894
1983
[PubMed]
Lee EH; Kang YK; and Bose K: Surgical correction of muscular torticollis in the older
child. J Pediatr Orthop,1986.6: 585-9, 6585
1986
[PubMed]
Colonna PC: Congenital torticollis. VA Med Mon,1927.53: 794-6, 53794
1927
Gruhn J, and Hurwitt ES: Fibrous sternomastoid tumor of infancy. Pediatr,1951.8: 522-6, 8522
1951
Tang S; Liu Z; Quan X; Qin J; and Zhang D: Sternocleidomastoid pseudotumor of infants and congenital
muscular torticollis: fine-structure research. J Pediatr Orthop,1998.18: 214-8, 18214
1998
[PubMed]