Treatment for developmental dysplasia of the
hip using the Pavlik harness
LONG-TERM RESULTS
J. Nakamura,
M. Kamegaya,
T. Saisu,
M. Someya,
W. Koizumi,
H. Moriya
From the Chiba
University, Chiba
City, Japan
J. Nakamura, MD, Resident
H. Moriya, MD, Professor
Department of Orthopaedic
Surgery
Graduate School of Medicine,
Chiba University, 1-8-1
Inohana, Chuo-ku, Chiba City,
260-8677, Japan.
M. Kamegaya, MD, Chief
Staff Surgeon
T. Saisu, MD, Staff Surgeon
Division of Orthopaedic
Surgery
Chiba Children’s Hospital, 579-1
Heta-chou, Midori-ku, Chiba
City, 266-0007, Chiba, Japan.
M. Someya, MD, Chief Staff
Surgeon
Division of Pediatric
Orthopaedic Surgery
Chiba Rehabilitation Center, 145-2 Honda-chou, Midori-ku,
Chiba City, 266-0005, Chiba,
Japan.
W. Koizumi, MD, Staff
Surgeon
Division of Orthopaedic
Surgery
Narita Red Cross Hospital, 90-1
Iida-chou, Narita City, 286-8523,
Chiba, Japan.
Correspondence should be sent
to Dr J. Nakamura; e-mail:
[email protected]
©2007 British Editorial Society
of Bone and Joint Surgery
doi:10.1302/0301-620X.89B2.
18057 $2.00
J Bone Joint Surg [Br]
2007;89-B:230-5.
Received 27 April 2006;
Accepted after revision 13
October 2006
230
We reviewed the medical records of 115 patients with 130 hips with developmental
dysplasia with complete dislocation in the absence of a neuromuscular disorder,
spontaneous reduction with a Pavlik harness, and a minimum of 14 years’ follow-up. The
mean age at the time of harness application was 4.8 months (1 to 12) and the mean time
spent in the harness was 6.1 months (3 to 12). A total of 108 hips (83.1%) were treated with
the harness alone and supplementary surgery for residual acetabular dysplasia, as defined
by an acetabular index > 30˚, was performed in 22 hips (16.9%).
An overall satisfactory outcome (Severin grade I or II) was achieved in 119 hips (91.5%) at
a mean follow-up of 16 years (14 to 32) with a follow-up rate of 75%. Avascular necrosis of
the femoral head was noted in 16 hips (12.3%), seven of which (44%) underwent
supplementary surgery and nine (56%) of which were classified as satisfactory. The
acetabular index was the most reliable predictor of residual acetabular dysplasia.
In 1950, Pavlik1-3 developed a functional harness for the management of developmental
dysplasia of the hip (DDH). Since then, the
Pavlik harness has gained widespread acceptance, with several reports showing favourable
rates of reduction and a low incidence of complications, such as avascular necrosis (AVN) of
the femoral head. The reported rate of reduction ranges from 70% to 99% and the incidence of AVN from 0% to 28%.4-16 These
discrepancies seem to be partly due to a lack of
clear criteria for the definition of subluxation
and dislocation. Johnson et al5 reported a
reduction rate of 99% and incidence of AVN
of 0%, but their study included subluxation.
Mubarak et al17 reported that the incidence of
AVN was higher when the harness was used to
treat dislocation rather than subluxation or
acetabular dysplasia. Therefore, the results for
dislocation should be distinguished from those
for subluxation.
There have been few reports of the longterm outcome on skeletal maturity of treating
complete dislocation with the Pavlik harness.18-22 The reported satisfactory outcome
ranges from 53% to 83%. Residual acetabular
dysplasia was one of the most influential factors leading to a poor outcome, although these
studies only included patients who were
treated conservatively and excluded those
treated by supplementary surgery. Salter23 suggested that early surgical correction of residual
hip dysplasia was necessary in patients over the
age of 18 months. We believe that the longterm outcome of patients treated with additional surgery should be included in the assessment of harness treatment.
The purpose of this retrospective review was
to clarify the long-term results of harness treatment at skeletal maturity, including supplementary surgery for complete dislocation in
DDH, to evaluate the incidence of AVN following the treatment, and to identify predictors of residual acetabular dysplasia.
Patients and Methods
The medical records of 221 patients who were
treated with a Pavlik harness (Nihan Gishusokuseizo Co., Tokyo, Japan) for DDH at Chiba
University Hospital and Chiba Children’s
Hospital between 1972 and 1991 were
reviewed. The criteria for inclusion in the study
were: 1) complete dislocation in the absence of
a neuromuscular disorder. This was diagnosed
clinically by a positive Ortolani sign,24 or
radiologically by lateral and cephalad displacement of the proximal end of the femur, accompanied by interruption of Shenton’s and
Perkin’s lines;25 2) the harness was applied as
an initial treatment and successfully reduced
the dislocation; 3) radiological follow-up until
at least 14 years of age. We excluded 23
patients with subluxations. Seven patients suffering from neuromuscular disorders (cerebral
THE JOURNAL OF BONE AND JOINT SURGERY
TREATMENT FOR DEVELOPMENTAL DYSPLASIA OF THE HIP USING THE PAVLIK HARNESS
231
within the first two weeks, the harness was discontinued
and closed reduction under general anaesthesia was
attempted after three weeks of preliminary horizontal tracReduced
tion. If the hip was still unstable, open reduction was conUnreduced
sidered. The harness was worn full-time during the first
four weeks after spontaneous reduction, and then part-time
for a further five months. During part-time wearing, the
Continuous harness
- Closed reduction
harness was removed only for bathing. The parents were
treatment
- Open reduction
instructed in the management of the harness. This schedule
followed the original method described by Pavlik.1,2
The medical records regarding the Ortolani sign24 were
Radiological evaluation at a
complete for only 108 of the 191 hips. Of the 108 hips, 92
mean age of 4.9 years (3 to 7)
were Ortolani positive and reducible and 16 were Ortolani
negative and irreducible. Reduction using the harness was
successful in 66 of the Ortolani-positive hips (72%) and 13
of the Ortolani-negative hips (81%).
Acetabular index < 30˚
Acetabular index ≥ 30˚
(residual acetabular
Of the 38 hips that failed to respond to harness treatdysplasia)
ment, 31 required closed and seven open reduction.
Radiological follow-up was carried out every 6 to 12
months
after the initial treatment and the plain radiograph
Outpatients follow-up
Supplementary surgery
Harness-only group
Supplementary group n=22 taken a mean age of 4.9 years (3 to 7) was used to evaluate
n=108 (83.1%)
(16.9%)
the indications for additional surgery. The acetabular index
(AI)26,27 was used as the basic indicator of residual acetabFig. 1
ular dysplasia. Periodic examination was continued for
Protocol for the initial treatment of developmental dysplasia of the hip.
patients with an AI < 30˚ (harness-only group), and additional surgery was indicated for those with an AI of 30˚ or
more (supplementary group) (Fig. 1). The operative
method depended upon the state of the joint and the surpalsy in three, chromosomal abnormality in two, skeletal geon’s preference. The centre-edge angle of Wiberg28 and
dysplasia in one, and inborn error of metabolism in one) the centre-head distance discrepancy29 in unilateral cases,
were also excluded. Harness treatment failed in all seven. In were also measured on the radiographs taken at a mean age
the remaining 191 patients (206 hips), harness treatment of 4.9 years (3 to 7).
The Severin classification system30 was used to evaluate
succeeded in 153 and failed in 38. The rate of reduction
was 81.6% (168 of 206). Follow-up in 38 patients was the result at the end of follow-up. Classes I and II were conuntil they were less than 14 years of age, so these patients sidered satisfactory and classes III, IV, V and VI were unsatwere excluded. We studied the remaining 115 patients (13 isfactory. AVN was classified by the method of Kalamchi
boys and 102 girls) with 130 affected hips (32 right, 68 left and MacEwen.31 Type I AVN was excluded from the statisand 15 bilateral). The mean age at harness application was tical analysis because of its good prognosis. Types II, III and
4.8 months (1 to 12). The mean time spent in the harness IV were considered significant.
was 6.1 months (3 to 12). The mean age at final examina- Statistical analysis. Overall results of the harness treattion was 16.0 years and 115 patients were followed up for ment. We evaluated whether reducibility (Ortolani sign
more than 15 years, with a follow-up rate of 75% (115 of positive or negative) affected outcome. Two-by-two contingency tables32 were computed to tabulate the incidence of
153).
Treatment protocol (Fig. 1). The harness was applied in the AVN and long-term outcome (satisfactory or unsatisfacout-patient clinic to patients who were more than three tory). Separate tables were computed for the reducibility.
months old or who weighed more than 6 kg. The baby lay Fisher’s exact probability test was applied. A p-value < 0.05
supine on a flat, semi-rigid bed and was free to roll and was considered significant.
turn. Parents were instructed to cradle the baby in their Long-term results of the harness-only and the supplemenarms whenever the baby cried. We examined the movement tary groups. Two-by-two contingency tables were comof the lower legs every few days during the first two weeks puted to tabulate long-term outcome. Separate tables were
and established whether the dislocation was reduced either computed for the incidence of AVN (absence and presence of
clinically or radiologically. Ultrasound screening was only AVN in the harness-only group or the supplementary group).
adopted from 1990, so the majority of patients were mon- Fisher’s exact probability test was applied. A p-value < 0.05
itored clinically and radiologically. As a result we did not was considered to be significant.
evaluate the ultrasound images in the few patients exam- Indicators of residual acetabular dysplasia. Correlation analyined by ultrasound. If reduction could not be obtained sis between AI and centre-edge angle and between AI and
Pavlik harness
VOL. 89-B, No. 2, FEBRUARY 2007
232
J. NAKAMURA, M. KAMEGAYA, T. SAISU, M. SOMEYA, W. KOIZUMI, H. MORIYA
Table I. Long-term results (Severin classification30)
Unsatisfactory
Satisfactory
Group (number of hips)
Ia
IIa
IIb
III
Harness-only (108)
Total (%)
63
33
100 (92.6)
Ib
1
3
6 2
8 (7.4)
Supplementary (22)
Total (%)
8
6
19 (86.4)
3
2
2 1
3 (13.6)
Overall (130)
71
4
5
Total (%)
119 (91.5)
39
8
IVa
3
11 (8.5)
Table II. Relationship between long-term results and avascular necrosis (AVN)
Satisfactory Unsatisfactory Significance*
Group (number of hips)
Harness-only (108)
AVN absent (%)
AVN present (%)
99
9
96 (97)
4 (44)
3 (3)
5 (56)
p < 0.0001*
Supplementary (22)
AVN absent (%)
AVN present (%)
15
7
14 (93)
5 (71)
1 (7)
2 (29)
NS
* Fisher’s exact probability test; NS, not significant
centre-head distance discrepancy at around five years of age
was performed using Spearman’s coefficient. A p-value <
0.05 was considered significant.
This study protocol was approved by our institutional
review board.
Results
Overall results of the harness treatment. Patients
were
followed-up for a mean of 16 years (14 to 32). At final follow-up 119 of 130 hips (91.5%) were considered satisfactory (Severin classes I and II). AVN was identified in 16 hips
(12.3%), seven type II, four type III, and five type IV. However, a satisfactory outcome was obtained in nine of these
(56%) with AVN. We excluded type I AVN, which occurred
in seven hips, all of which were classified as Severin Ia.
At a mean age of 4.9 years (3 to 7), 108 of the 130 hips
(83.1%) showed an AI of less than 30˚ and were treated
only in the harness (harness-only group). However, 22 hips
(16.9%) showed residual acetabular dysplasia, defined by
an AI of 30˚ or more, and underwent supplementary surgery (supplementary group), which included 15 Salter
innominate osteotomies,23,33 four combined procedures of
Salter innominate osteotomy and femoral varus osteotomy,
and three Pemberton osteotomies.34
Of the 79 hips reduced by the harness, 66 were reducible
(Ortolani positive) and 13 were irreducible (Ortolani negative). Of the 66 reducible hips, 61 (92%) were classified as
Severin I/II and AVN was noted in six (9%). All of the 13
irreducible hips (100%) were classified as Severin I/II, and
AVN was noted in one (8%). There was no statistically significant difference between reducibility and outcome.
In 30 of the 38 hips treated by closed or open reduction
the patient had reached at least 14 years of age. Of these 30
hips, 25 were Severin I/II (83%) despite AVN in eight
(27%).
Long-term results of the harness-only and the supplementary groups. In the harness-only group 100 of 108 hips
(93%) were considered satisfactory (Severin class I or II) at
final follow-up and 19 of 22 hips (86%) in the supplementary group (Table I). Of the 16 hips with AVN, nine were
treated conservatively, and seven showed residual acetabular dysplasia and underwent supplementary surgery.
There was no incidence of AVN after supplementary surgery.
In the absence of AVN in the harness-only group, 96 hips
were satisfactory and three unsatisfactory; in the presence
of AVN, four hips were satisfactory and five unsatisfactory
(Table II). There was a significant difference between hips
with AVN and those without AVN in the long-term results
of the harness-only group (p < 0.0001). In the absence of
AVN in the supplementary group, 14 hips were satisfactory
and one was unsatisfactory; in the presence of AVN, five
hips were satisfactory and two were unsatisfactory. There
was no significant difference between hips with and without AVN in the long-term results of the supplementary
group.
Indicators of residual acetabular dysplasia. The mean AI at
a mean age of 4.9 years (3 to 7) was 22.6˚ (12˚ to 34˚) in the
harness-only group and 33.9˚ (30˚ to 43˚) in the supplementary group. There was a predictably significant difference
between these groups (p < 0.0001). The mean centre-edge
angle at a mean age of 4.9 years (3 to 7) was 17.7˚ (-3˚ to
31˚) in the harness-only group and 3.4˚(-30˚ to 12˚) in the
supplementary group. The mean centre-head distance discrepancy was 3.0% (-6.6% to 17%) in the harness-only
group and 8.5% (0% to 26.6%) in the supplementary
group. Correlation between AI and centre-edge angle at a
mean age of 4.9 years (3 to 7) was shown by a strong negative Spearman’s correlation coefficient of -0.85 (95% CI
-0.89% to -0.79%). Correlation between AI and centrehead distance discrepancy was shown by a moderate Spearman’s correlation coefficient of 0.40 (95% CI 0.21% to
0.55%).
Discussion
The long-term results of the Pavlik harness used for dislocation only in this study were satisfactory compared with
previous reports. Fujioka et al22 reported a 78% satisfactory outcome with 23.6 years of follow-up, but included
both dislocation and subluxation. Mubarak et al17 reported
that if subluxation was considered a type of dislocation, the
results were better. We believe that one reason for our
favourable long-term results was that additional surgery
for residual acetabular dysplasia was performed when indicated on the radiograph at a mean age of 4.9 years (3 to 7)
(Fig. 2). Mitani et al21 reported a satisfactory outcome in
only 67% of patients treated with the harness and no addiTHE JOURNAL OF BONE AND JOINT SURGERY
TREATMENT FOR DEVELOPMENTAL DYSPLASIA OF THE HIP USING THE PAVLIK HARNESS
233
Fig. 3a
Fig. 2a
Fig. 3b
Fig. 2b
Anteroposterior radiograph in a five-year-old girl with bilateral developmental dysplasia of the hip treated with the Pavlik harness. The
acetabular index was 34˚ on the right and 39˚ on the left. Only the left
hip had a Salter innominate osteotomy because her parents refused the
procedure on the right. Figure 2b – Anteroposterior radiograph at 14
years of age. The left hip has developed good acetabular cover (centreedge angle 32˚) and was classified as Severin class Ia. The right hip
continues to have acetabular dysplasia (centre-edge angle 15˚) and
shows a break in Shenton’s line (Severin class IVa).
tional surgery for residual acetabular dysplasia. Tucci et
al18 reported a satisfactory outcome in 83% of patients followed up for 12 years, but excluded those who required a
supplementary operation for acetabular dysplasia. Our
long-term results include both the harness-only group and
the supplementary surgery group.
Albinana et al35 have shown that AI is a reliable indicator
of acetabular development. They concluded that an AI > 30˚
four years after closed or open reduction was associated
with an 80% probability of developing a Severin grade III/
IV hip. On the other hand, Murakami and Katada19
reported that a minimum centre-edge angle of 10˚ at five or
VOL. 89-B, No. 2, FEBRUARY 2007
Fig. 3c
Figure 3a - Anteroposterior radiograph of a five-year-old girl with left
developmental dysplasia of the hip. The acetabular index was 27˚ and
she was treated with a harness only. Figure 3b – Anteroposterior radiograph at 10 years of age. The left hip developed with good acetabular
cover (centre-edge angle 24˚) but premature lateral growth arrest was
noted. The result was expected to be favourable at that time. Figure 3c
– Anteroposterior radiograph at 20 years of age. The valgus deformity
due to the early closure of the lateral part of the physis has progressed,
resulting in an unsatisfactory outcome (Severin class III; centre-edge
angle 18˚).
six years of age may be a reasonable threshold of normality.
However, Kim et al27 reported that the centre-edge angle is
only useful in children over the age of five years because the
234
J. NAKAMURA, M. KAMEGAYA, T. SAISU, M. SOMEYA, W. KOIZUMI, H. MORIYA
centre of the femoral head is difficult to define in a younger
child with an eccentrically-located ossific nucleus. Ogata et
al36 reported that it was sometimes difficult to distinguish
precisely the lateral edge of the acetabulum because of the
indistinct shadow of the sourcil. Chen et al29 demonstrated
that centre-head discrepancy was the most significant correlative factor in predicting the outcome of acetabular
development, and Kim, Kim and Yoo37 reported that a
centre-head distance discrepancy > 6% and the upward orientation of the sourcil at four or five years of age were indications for additional surgery. However, centre-head
distance discrepancy can only be used in unilateral cases.
Because AI correlated with centre-edge angle and centrehead distance discrepancy, and satisfactory results of 86%
were obtained in the supplementary group, we believe that
an AI > 30˚ around five years of age is the most useful predictor of residual acetabular dysplasia and an indicator for
additional surgery.
Severin30 stated that a follow-up study that does not
include the majority of patients originally treated is incomplete. We believe that our follow-up rate is higher than
those previously reported.18-22 Cashman et al14 reported a
prospective study with 89.9% follow-up, but their mean
follow-up period was only 6.5 years. This is not enough to
clarify the long-term results of DDH because the Severin
classification is different in those between six and 13 years
of age and over 14 years of age.33,38 Furthermore, Koizumi
et al39 reported that Kalamchi29 type II AVN may not be
recognised until after ten years of age. We experienced such
a case (Fig. 3) and emphasise the importance of follow-up
until at least skeletal maturity. The reported incidence of
AVN in complete dislocation ranges from 7.3% to 14% at
skeletal maturity.18-22
Our use of the harness followed Pavlik’s original method.1,2
He used the harness for all patients with dislocation up to the
age of one year. Viere et al40 recommended a trial of the harness in patients with a typical dislocation up to the age of
seven months, even if the dislocation could not be reduced by
the Ortolani manoeuvre. In our series there was no statistically
significant difference in reducibility (as assessed by the Ortolani sign) or outcome. On the other hand, Mostert, Tulp and
Castelein41 suggested that the harness should not be used in
Graf type IV hips,42 as in their hands it was successful in only
50% of such hips. The incidence of AVN in this study was
higher in hips which failed harness treatment and required
closed or open reduction than in those that responded to harness treatment. However, it is still unclear whether wearing the
harness for even a short time affects the occurrence of AVN.
Herring43 suggested that the harness has a screening role. Hips
which failed to respond to harness treatment were recalcitrant,
at risk of failure with other types of treatment, and required a
cautious approach. The influence on AVN of further treatment should not be ignored. We never forcibly reduced dislocated hips with the harness and never continued to use it
unless spontaneous reduction occurred within two weeks.
Takahashi9 reported that spontaneous reductions were
observed as early as three to four days, and usually within
a week after application of the harness. Harris et al12 also
suggested that the treatment should be abandoned if the hip
could not be reduced after two to four weeks of treatment.
In the harness-only group there was a significant difference in outcome between those with AVN and those without, but there was no significant difference between those
with and without AVN in the supplementary group. We
suggest that supplementary surgery may improve the outcome in AVN with residual acetabular dysplasia.
Since 1991 we have modified the use of the Pavlik harness to reduce the incidence of AVN, based on the studies
by Grill et al10 and Ramsey et al.4 Small pillows are placed
under the knees of supine babies to allow their abduction
within a safe zone a few days after reduction, when they do
not want to move their legs. We start the application routinely at about 70˚ of flexion and increase it slowly, as
babies and their hips need time to adapt to the therapeutic
position of the harness. We repeatedly explain the procedure to parents by means of our brochures to promote a
better understanding of the treatment. Spontaneous reduction is monitored using ultrasonography via an anterior
approach.44,45 In a recent short-term study, the incidence of
AVN was reduced to 0%.46
The incidence of AVN was nil in the group initially
reduced with the Pavlik harness in Chiba Children’s Hospital. The initial treatment of developmental dysplasia of the
hip is important if AVN of the femoral head is to be
avoided.
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
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