To evaluate the residual acetabular dysplasia in Graf type II hips after Pavlik harness treatment with a radiographic follow-up at 2 years of age.

We retrospectively reviewed the developmental dysplasia of the hip patients who were treated with the Pavlik harness between March 2018 and February 2022. Patients with Graf type II hip dysplasia who had at least one radiographic follow-up after 2 years of age were included. The following information, sex, laterality, affected side, age at harness initiation, treatment duration, α angle, and the morphology of bony roof, was collected and studied. We evaluated the radiographic acetabular index at the last follow-up and defined the value of greater than 2 standard deviations as residual acetabular dysplasia.

A total of 33 patients (53 hips) met the criteria. The mean initial α angle was 53.4°; the mean age at Pavlik harness initiation was 10.9 weeks. The mean treatment duration was 10 weeks. The mean α angle at the last ultrasound follow-up was 64.9°. The mean age of the last radiographic follow-up was 2.6 years, and 26 hips had a residual acetabular dysplasia with acetabular indexes greater than 2 standard deviations above the mean. The morphology of the acetabular bony rim (odds ratio = 4.333, P = 0.029) and age of initial treatment <12 weeks (odds ratio = 7.113, P = 0.014) were seen as significant predictors for a higher acetabular index more than 2 years of age.

A notable incidence of residual acetabular dysplasia after Pavlik harness treatment in Graf type II hips, wherein the acetabular bony roof with a blunt rim at the end of treatment and initial age after 12 weeks were independent predictors associated with residual acetabular dysplasia.

Therapeutic studies, IV.

Some patients with developmental dysplasia of the hip (DDH) before 6 months of age successfully treated by Pavlik Harness (PH) still had persistent acetabular dysplasia (PAD). This study aimed to investigate the incidence and risk factors for PAD in patients with DDH treated by PH. We retrospectively reviewed the data of 89 patients (109 hips; mean age, 3.2 ± 1.5 months) with DDH treated by PH. Prior to treatment, all patients underwent ultrasound examination and classified according to Graf's method. PH was terminated once the hip achieved imaging recovery criteria. At final follow-up, the acetabular index (AI), center-edge angle (CEA) of Wiberg were measured on radiograph. Overall, 67/109 hips (61.5%) had successful PH treatment. Among these 67 hips, 58 hips (86.6%) achieved satisfactory outcome, nine (13.4%) had PAD. Age of the patients with PAD (4.3 ± 1 months) was significantly higher than those without PAD (2.8 ± 1.5 months) ( P = 0.001). Hips with PAD had higher mean Graf grade than those with satisfactory outcome ( P = 0.014). Logistic regression-confirmed age and Graf classification were risk factors for PAD. Overall, 55/67 (82.1%) met imaging recovery criteria to stop PH treatment, whereas 12/67 hips (17.9%) did not. The rate of PAD at final follow-up in patients achieving recovery criteria (4/55; 7.3%) was significantly lower than those not achieving it (41.7%) ( P = 0.007). In conclusion, age and Graf classification are risk factors for PAD. If hips are not normal at the end of PH treatment, the risk of PAD increases further.

The purpose of this study was to evaluate the rate of residual acetabular dysplasia (RAD), defined as an acetabular index (AI) of >90th percentile of age and sex-matched controls, in a cohort of infants successfully treated with the Pavlik harness (PH).

We retrospectively studied typically developing infants at a single center, with at least 1 dislocated hip, that was successfully treated with a PH and had a minimum of 48 months follow-up. Hip dislocation was defined as <30% femoral head coverage at rest on pretreatment ultrasound or IHDI grade 3 or 4 on the pretreatment radiograph.

Forty-six dislocated hips (41 infants) were studied (4 males and 37 females). Brace treatment was initiated at an average age of 1.8 months (range: 2 d to 9.3 mo) and was maintained for an average of 10.2 months (range: 2.3 to 24.9 mo). All hips achieved IHDI grade 1 reduction. Five of 46 hips (11%) had an AI >90th percentile at the conclusion of bracing. Average follow-up was 6.5 years (range: 4.0 to 15.2 y). We found a 30% incidence of RAD (14/46 hips) on final follow-up radiographs. Of these hips, 13/14 (93%) had AI <90th percentile at the end of brace treatment. Comparing children with and without RAD, there were no differences in age at the initial visit or brace initiation, total follow-up, femoral head coverage at the initial visit, alpha angle at the initial visit, or total time in the brace (P > 0.09).

In a single-center cohort of infants with dislocated hips treated successfully with a PH, we observed a 30% incidence of RAD at a minimum 4.0-year follow-up. Normal acetabular morphology at the end of brace treatment did not result in normal acetabular morphology at the final follow-up in 13/41 hips (32%). We recommend that surgeons should pay close attention to the year-over-year change in both the AI and AI percentile.

Level IV: case series.

This study was designed to analyze the cartilaginous predictors of residual acetabular dysplasia (RAD) after early treatment of developmental dysplasia of the hip and their diagnostic accuracy.

Databases such as PubMed, Embase, Cochrane, and Web of science were searched to screen the literature. The quality of the literature was assessed by the QUADAS-2 tool. Qualitative and quantitative synthesis of literature were performed based on extracted data. For quantitative synthesis studies, the sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve with corresponding confidence intervals were calculated.

For the cartilaginous acetabular index (CAI) group, the combined values of sensitivity, specificity, and DOR were 0.80 (95% CI = 0.54-0.93), 0.73 (95% CI = 0.57-0.84), and 10.62 (95% CI = 3.96-28.53), respectively. The corresponding values in the cartilaginous center-edge angle (CCE) group were 0.71 (95% CI = 0.57-0.82), 0.78 (95% CI = 0.66-0.87), and 8.64 (95% CI = 3.08-24.25), respectively. The area under the curve (AUC) of SROC was 0.82 (95% CI = 0.78-0.85) and 0.80 (95% CI = 0.76-0.83) for the CAI and CCE groups. The CAI group had higher sensitivity, DOR, and AUC than the CCE group.

Both of these two groups have good diagnostic accuracy, and CAI/L-AI has a little edge over CCE/L-CEA. However, there is still more research needed to determine whether they can be used as independent indications for secondary orthopedic surgery.Systematic review registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier: [CRD42022338332].

Residual acetabular dysplasia occurs in up to a third of patients treated successfully for developmental dysplasia of the hip (DDH) and has been found to be a significant risk factor for early hip osteoarthritis (OA).

Age at the time of initial reduction and the initial severity of DDH have been linked to residual acetabular dysplasia. An anteroposterior pelvic radiograph is the main diagnostic modality, but MRI also provides valuable information, particularly in equivocal cases. The literature supports intervening when significant residual acetabular dysplasia persists at 4-5 years of age, and common surgical indications include acetabular index (AI) > 25°-30°, lateral center-edge angle (LCEA) < 8°-10°, and a broken Shenton's line on radiographs; and a cartilaginous acetabular angle (CAI) > 18°, cartilaginous center-edge angle (CCE) < 13°, and/or the presence of high-signal intensity areas on MRI. Surgical options include redirectional pelvic osteotomies and reshaping acetabuloplasties, which provide comparable radiographic and clinical results.

RAD is common after treatment of DDH and requires regular follow-up for diagnosis and appropriate management to decrease the long-term risk of OA. Long-term outcomes of patients treated with pelvic osteotomies are generally favorable, and the risk of OA can be decreased, although the risk of total hip replacement in the long-term remains.

Following successful treatment of developmental hip dysplasia with a Pavlik harness, controversy exists over the benefit of continued harness use for an additional "weaning" period beyond ultrasonographic normalization versus simply terminating treatment. Although practitioners are often dogmatic in their beliefs, there is little literature to support the superiority of 1 protocol over the other. The purpose of this study was to compare the radiographic outcomes of 2 cohorts of infants with developmental hip dysplasia treated with Pavlik harness, 1 with a weaning protocol and 1 without.

This was a comparative review of patients with dislocated/reducible hips and stable dysplasia from 2 centers. All patients had pretreatment ultrasounds, and all started harness treatment before 3 months of age. On the basis of power analysis, a sufficient cohort of hips were matched based on clinical examination, age at initiation, initial α angle, and initial percent femoral head coverage. Patients from institution W (weaned) were weaned following ultrasonographic normalization, whereas those from institution NW (not weaned) immediately ceased treatment. The primary outcome was the acetabular index at 1 year of age.

In total, 16 dislocated/reducible and 16 stable dysplastic hips were matched at each center (64 total hips in 53 patients). Initial α angle and initial femoral head coverage were not different between cohorts for either stable dysplasia (P=0.59, 0.81) or dislocated/reducible hips (P=0.67, 0.70), respectively. As expected, weaned hips were treated for significantly longer in both the stable dysplasia (1540.4 vs. 1066.3 h, P<0.01), and dislocated/reducible cohorts (1596.6 vs. 1362.5 h, P=0.01). Despite this, we found no significant difference in the acetabular index at 1 year in either cohort (22.8 vs. 23.1 degrees, P=0.84 for stable dysplasia; 23.9 vs. 24.8 degrees, P=0.32 for Ortolani positive).

Despite greater total harness time, infants treated with additional Pavlik weaning did not demonstrate significantly different radiographic results at 1 year of age compared with those who were not weaned. However, differences in follow-up protocols between centers support the need for a more rigorous randomized controlled trial.

Level III.

Currently, hip sonography is used for early diagnosis and for monitoring developmental dysplasia of the hip (DDH) treatment in many countries. An early pioneer of ultrasonography for early diagnosis of DDH was Graf. Based on the Graf approach, hip ultrasonography is more sensitive and specific than radiography for the diagnosis of DDH, because of its capability to show cartilaginous structures of the hip joint. The aim of this study was to compare radiographic and ultrasonographic findings in patients treated for DDH. This study included 88 infants (98hips) treated for DDH. Radiography was simultaneously used for treatment and follow-up evaluation in addition to ultrasonography after six months of age. A retrospective evaluation was made of the ultrasonographs and radiographs of these infants. Of the total 98 hips, 28 were normal both ultrasonographically and radiographically, and a pathologic hip was demonstrated in 32 hips both sonographically and radiographically. Hip ultrasonography showed abnormal development in 32 hips, while radiography showed abnormal development in 70 hips. In 38 hips, the findings were normal according to ultrasonography but pathological according to radiography. There were no hips that were normal radiographically but pathological sonographically. When radiography is accepted as the standard imaging method in our study patients, the sensitivity and specificity of hip ultrasonography were determined as 45.7% [95% confidence interval (CI): 41.5-45.7] and 100% (95% CI: 89.4-100), respectively. These findings suggest that hip maturation apparent on ultrasonography may not be consistent with radiographic hip development in infants treated for DDH.

We asked whether patient-specific factors and ultrasound (US) measurements of hip dysplasia severity at initial examination influence short-term residual acetabular dysplasia in patients successfully treated with Pavlik harness for developmental hip dysplasia.

After IRB approval, 134 hips (84 patients) successfully treated by the Pavlik method between August 2011 and October 2014 with follow-up at 12 months of age were identified. Early successful treatment was defined as normal examination and US after approximately 12 weeks of Pavlik treatment. Multivariate linear and logistic regression models were used to identify factors associated with acetabular index (AI) measurements at 12 months as well as factors associated with an increase in AI between the 6- and 12-month timepoints (dysplastic progression).

The study consisted of 134 hips (84 patients). The distribution of dysplastic, Barlow, and Ortolani hips was 44.8% (N=60), 30.6% (N=41), and 24.6% (N=33), respectively. The crude incidence of residual dysplasia at the 6-month visit (AI>30 degrees) was 11.7% (12/102). The incidence of residual dysplasia at the 12-month visit (AI>28 degrees) was 11.8% (13/111). Graf type was the only variable associated with AI values at the 12-month visit (mean difference: Graf type-IV-Other, 2.6; 95% confidence interval, 0.3-4.9; P=0.026).

The risk of residual acetabular dysplasia after normal hip US following Pavlik treatment is not negligible. Radiographic surveillance is warranted to monitor and screen for dysplasia progression. Patients with dislocated Graf type-IV hips at diagnosis are at increased risk of residual acetabular dysplasia at 1 year after successful treatment with the Pavlik method.

Level III-therapeutic study.

The Pavlik method is the most common method used for treatment of developmental dysplasia of the hip (DDH). Late acetabular dysplasia despite successful treatment, however, has had varied reporting. A systematic review was performed, investigating the long-term outcomes of DDH treated with the Pavlik method. Seventeen studies met inclusionary criteria, including 6029 hips treated with an average of 5.29 years follow-up. Radiographic evidence of late dysplasia was present in 280 hips, with 109 hips requiring additional surgery. A specified treatment algorithm had significantly decreased rates of radiographic dysplasia (3.8% vs 17.6%, p = 0.004).

IV.

Residual acetabular dysplasia is a frequent cause of secondary osteoarthritis of the hip and its management is still controversial. The aim of this review is to describe residual acetabular dysplasia, to estimate the age limit above which surgical management is needed, and to emphasize the role of assistive imaging in evaluating predictive parameters for future acetabular development. A decision-making algorithm is presented.