Residual dysplasia after successful Pavlik harness treatment: early ultrasound predictors

The role of the cartilaginous to osseous acetabular angle ratio in children with developmental dysplasia of the hip

Purpose

This study aims to demonstrate the use of the cartilaginous to osseous acetabular angle ratio (AAR) in surgical decision-making for hip dysplasia.

Methods

Data were collected from patients who underwent an MRI of the hip after conservative treatment for developmental dysplasia of the hip between August 2019 and 2022. The data included demographic information as well as an anteroposterior pelvic radiograph. The osseous acetabular index (OAI) was measured using x-ray, while the cartilaginous acetabular index (CAI) and the cartilaginous acetabulum head index (CAHI) were measured using MRI. The square of the CAI to OAI, AAR, was calculated. The patients in the residual hip dysplasia (RHD) group were categorized as having an OAI above 20°. During the postoperative follow-up, we evaluated the patients in this group who underwent Bernese triple pelvic osteotomy. Data on surgical patients with an observation period that exceeded 1 year were collected and analyzed. The distribution of the AAR among the different groups was analyzed. A receiver operating characteristic (ROC) predictive model was constructed using the AAR of the patients in the normal and surgical groups to evaluate the need for surgery.

Results

It was found that there was a significant difference in the OAI, CAI, CAHI, and AAR between the RHD group (OAI 26.15 ± 3.90°, CAI 11.71 ± 4.70°, CAHI 79.75 ± 6.27%, and AAR 5.88 ± 4.24) and the control group patients (OAI 16.77 ± 5.39°, CAI 6.16 ± 3.13°, CAHI 85.05 ± 4.91%, and AAR 2.71 ± 2.08) (p < 0.001). A total of 93.5% of the control group patients had an AAR ≤5, while only 6.5% had an AAR >5. The results of postoperative imaging follow-up were "excellent" in 52 patients and "good" in 3, while the functional follow-up results were excellent in 53 and good in 2. In 15 patients, the observation period exceeded 1 year. The mean observation period was 633.1 ± 259.6 days and the preoperative CAHI was 71.7 ± 4.8%. Of the patients with an AAR >5, a substantial 94.8% (55/58) of them were reported to have undergone surgery, while all patients with an AAR less than or equal to 5 did not undergo surgery (91/91). Based on the ROC, a cutoff value of 5.09 was identified for the need for surgery in children with RHD.

Conclusions

A surgical decision for residual hip dysplasia can be based on the AAR. An AAR >5 may be a potential indicator for surgical intervention in patients with RHD.

Comparison of outcomes of different Graf grades of developmental dysplasia of the hip in infants treated with Tubingen splint versus Pavlik harness - A systematic review

This systematic review was designed to compare the outcomes of the two braces against each other classified by the Graf method. The databases sources included PubMed, Embase, and Google Scholar. The keywords included "DDH Tubingen versus Pavlik" and Tubingen and Pavlik separately. Included papers provided specific data regarding success and failure rate, avascular necrosis (AVN), duration, and age of intervention. The excluded studies discussed surgeries, diagnosis and mechanism, and ones that weren't in English. Total of 20 papers were included, resulting in 1243 Tubingen and 420 Pavlik samples. It was seen that the Tubingen splint had a statistically significant greater success rate and lower failure rate for Graf 2, D, and 3 hips, while both braces were not very successful for Graf 4 at success rates less than 60 %. Tubingen also had a lower incidence of AVN. Both braces shared similar ages of intervention, duration, and time per day. Both braces are very comparable to each other, each having better success rates for lower Graf grades, which points to the importance of bracing earlier to improve the success rates. The Tubingen splint had a higher success rate, lower failure rate, and lower AVN rate compared to the Pavlik harness. This points to the Tubingen splint potentially being the preferred option for bracing in infants.

The utility of ultrasound and plain radiographs in the management of developmental dysplasia of the hip

The purpose of this study is to assess the utility of follow-up radiological imaging in the management of developmental dysplasia of the hip (DDH) in patients successfully treated with the Pavlik harness. A retrospective review was conducted on all children under 6 months diagnosed with DDH at a tertiary pediatric hospital between January 2004 and December 2018. Inclusion criteria included successful Pavlik harness treatment following a standardized protocol with complete radiological documentation at 2 years of age. Ultrasonography was reviewed to measure the α and β angles and Graf classification. Anteroposterior pelvic radiographs were evaluated for the acetabular index and residual acetabular dysplasia. Seventy-eight hips from 57 infants were included in this study. The mean 6-month, 12-month and 2-year acetabular index of Graf I, IIa and IIc hips on ultrasound at 12 weeks were within the normal range according to age. There were no Graf IIb, IId, III and IV hips. All infants had normal radiographs at 2 years follow-up. The 6- and 12-month residual dysplasia rates in patients with DDH normalization at 12 weeks and 6 months range from 2.5 to 8.82%. Regardless of when the acetabular index normalized, all patients eventually had normal hip radiographs at 2 years of age. Following a standardized protocol, patients undergoing Pavlik harness treatment for DDH with Graf I and IIa hips at 12 weeks are likely to have normal plain radiographs at discharge. The incidence of residual dysplasia is very low and hence, radiographic surveillance is probably unnecessary until discharge at 2 years. Level II, retrospective study.

Acetabular index as an indicator of Pavlik harness success in grade I developmental dysplasia of the hip: A retrospective study

Purpose

Some articles have focused on the effectiveness of the Pavlik harness treatment for unstable and dislocated hips, yet data on monitoring its effectiveness with the acetabular index remains elusive. Therefore, this study aimed to assess Pavlik harness effectiveness in infants ≤6 months diagnosed with grade I developmental dysplasia of the hip using acetabular index improvement and identify the possible predictors of successful Pavlik harness treatment.

Methods

A retrospective review of infants with grade I acetabular dysplasia treated with a Pavlik harness and monitored with anteroposterior pelvis X-rays at presentation and follow-up. Successful treatment was defined as achieving an acetabular index <30°.

Results

A total of 231 infants with acetabular dysplasia were treated with a Pavlik harness. A successful outcome was achieved in 135 infants (58.4%). Younger age, lower initial acetabular index, and patients with unilateral developmental dysplasia of the hip were significant predictors of a successful outcome. An age of 4.5 months or older was found to be the threshold for an unsuccessful result following Pavlik harness treatment, with a sensitivity of 65.2% and specificity of 57.3%. An initial acetabular index of 35.5° was found to be the threshold for an unsuccessful result, with a sensitivity of 83.7% and specificity of 61.5%.

Conclusion

Pavlik Harness's success in correcting the acetabular index in acetabular dysplasia patients was related to unilateral cases, a younger age at presentation, and a lower initial acetabular index. The thresholds for unsuccessful treatment were an age of 4.5 months or greater and an acetabular index of 35.5° or higher.

Residual acetabular dysplasia after Pavlik harness treatment for Graf type II hips

Purpose

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.

Methods

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.

Results

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.

Conclusions

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.

Levels of evidence

Therapeutic studies, IV.

Incidence and risk factors for persistent acetabular dysplasia in patients with developmental dislocation of the hip treated by Pavlik Harness

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.

Defining the Incidence of Residual Acetabular Dysplasia After Successful Reduction With a Harness

BACKGROUND

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).

METHODS

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.

RESULTS

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).

CONCLUSION

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 OF EVIDENCE

Level IV: case series.

Artificial Intelligence-Assisted Ultrasound Diagnosis on Infant Developmental Dysplasia of the Hip Under Constrained Computational Resources

OBJECTIVES

Ultrasound (US) is important for diagnosing infant developmental dysplasia of the hip (DDH). However, the accuracy of the diagnosis depends heavily on expertise. We aimed to develop a novel automatic system (DDHnet) for accurate, fast, and robust diagnosis of DDH.

METHODS

An automatic system, DDHnet, was proposed to diagnose DDH by analyzing static ultrasound images. A five-fold cross-validation experiment was conducted using a dataset containing 881 patients to verify the performance of DDHnet. In addition, a blind test was conducted on 209 patients (158 normal and 51 abnormal cases). The feasibility and performance of DDHnet were investigated by embedding it into ultrasound machines at low computational cost.

RESULTS

DDHnet obtained reliable measurements and accurate diagnosis predictions. It reported an intra-class correlation coefficient (ICC) on α angle of 0.96 (95% CI: 0.93-0.97), β angle of 0.97 (95% CI: 0.95-0.98), FHC of 0.98 (95% CI: 0.96-0.99) and PFD of 0.94 (95% CI: 0.90-0.96) in abnormal cases. DDHnet achieved a sensitivity of 90.56%, specificity of 100%, accuracy of 98.64%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 98.44% for the diagnosis of DDH. For the measurement task on the US device, DDHnet took only 1.1 seconds to operate and complete, whereas the experienced senior expert required an average 41.4 seconds.

CONCLUSIONS

The proposed DDHnet demonstrate state-of-the-art performance for all four indicators of DDH diagnosis. Fast and highly accurate DDH diagnosis is achievable through DDHnet, and is accessible under constrained computational resources.

Closed reduction and plaster immobilization: an alternative solution for patients with developmental dysplasia of the hip who failed Pavlik harness treatment

BACKGROUND

The current study aims to investigate the clinical efficacy of closed reduction and cast immobilization for patients with developmental dysplasia of the hip (DDH) who failed Pavlik harness treatment.

METHODS

Patients with DDH who underwent cast immobilization under general anaesthesia after the failure of the Pavlik harness or Tübingen brace treatment between January 2015 and December 2020 were retrospectively recruited. General information, including Graf classification of initial diagnosis, initial treatment, age of cast immobilization, IHDI classification, AI index, avascular necrosis (AVN), and residual dysplasia, was collected. The incidence of AVN and late acetabular dysplasia (LACD) was also estimated. Moreover, factors related to AVN and LACD were investigated by multiple logistic regression analysis.

RESULTS

Thirty-four patients (47 hips) were finally included in the current study. Of these patients, 31 hips (66.0%) were successfully treated with closed reduction and cast immobilization. Open reduction was successfully performed in 16 hips (34.0%). Till the latest follow-up, LACD and AVN were found in 13 (27.7%) and 10 (21.3%) hips, respectively. In the open reduction group, type III and IV of the IHDI classification and type IV of the Ultrasound Graf classification were significantly higher when compared with the closed reduction group. Multiple logistic regression showed that failure of closed reduction was related to the initial types of the Ultrasound Graf and IHDI classifications.

CONCLUSIONS

Although the success rate of closed reduction after early harness failure in DDH is only 66%, we still advocate closed reduction as a first-line treatment for children who have failed sling treatment. Even if closed reduction fails, open reduction can still achieve acceptable results.

Prediction of Late Dysplasia Based on Ultrasound and Plain X-Ray at 6 Months

BACKGROUND

Developmental dysplasia of the hip represents a spectrum of deformity. Residual dysplasia at 2 years of age is associated with an increased risk for osteoarthritis and functional limitations. We compared the prognostic value of 6-month imaging modalities and aimed to identify optimal diagnostic metrics for the prediction of residual dysplasia.

METHODS

After IRB approval, patients who underwent Pavlik treatment between 2009 and 2018 with 2-year follow-up were identified. Sonographs [ultrasound (US)] and radiographs (x-ray) were obtained at 6-month and 2-year-old visits. Dysplasia at 2 years was defined as an acetabular index (AI) >24 degrees. Receiver operating characteristic curves were constructed to quantitatively compare the prognostic ability of US and x-ray-based measures at 6 months. Youden's index [(YI) (values range from 0 (poor test) to 1 (perfect test)] was used to evaluate existing cutoffs at 6 months of age (normal measurements: alpha angle (AA) ≥60 degrees, femoral head coverage (FHC) ≥50%, and AI <30 degrees) relative to newly proposed limits.

RESULTS

Fifty-nine patients were included, of which 28.8% of patients (95% CI: 17.3 to 40.4%) had acetabular dysplasia at 2 years. After adjusting for sex, AA [Area under the Curve (AUC): 80] and AI (AUC: 79) at 6 months of age were better tests than FHC (AUC: 0.77). Current diagnostic cutoffs for AA (YI: 0.08), AI (YI: 0.0), and FHC (YI: 0.06) at 6 months had poor ability to predict dysplasia at 2 years. A composite test of all measures based on proposed cutoffs (AA ≥73 degrees, FHC > 62% and AI ≤24 degrees) was a better predictor of dysplasia at 2 years (Youden's index (YI): 0.63) than any single metric.

CONCLUSIONS

The rate of residual dysplasia remains concerning. The 6-month x-ray and US both play a role in the ongoing management of the developmental dysplasia of the hip. The prediction of dysplasia is maximized when all metrics are considered collectively. Existing parameters were not accurate; We recommend the following cutoffs: AA ≥73 degrees, FHC > 62%, and AI ≤24 degrees. These cutoffs must be validated.

LEVEL OF EVIDENCE

Prognostic Level II.

Radiological predictors associated with success of treatment for developmental dysplasia of hip using the Pavlik harness: A retrospective study

BACKGROUND

While various predictors of treatment outcome of Pavlik harness have been reported, appropriate indications for treatment and relationships between patient characteristics and outcome are unclear. The present study aimed to identify radiological predictors for successful Pavlik harness treatment of DDH at the initiation of treatment and investigate the progression of radiological characteristics after successful treatment.

METHODS

One-hundred-forty-two of 527 infants who visited our hospital for secondary screening of DDH were treated with the Pavlik harness. One-hundred-eight hips of 108 infants experienced successful treatment and could be followed up until 3 years of age (group S); treatment was unsuccessful within the first 2 weeks for 22 hips of 21 infants (group F). We investigated the Graf classification and radiological parameters.

RESULTS

We observed the ipsilateral-side measurements of distance A and B as defined by Yamamuro and Chene's method to be significantly smaller and greater, respectively, in group F compared with those of group S. Group F tended to exhibit the smaller distance A and larger distance B compared to the group S among the same Graf type. The cut-off values for successful treatment at were >7.4 mm at initiation of treatment for distance A and <11.2 mm for distance B. The acetabular index (AI) of the ipsilateral side at the initiation of treatment was significantly correlated with that at 1 and 3 years of age. Patients with an AI of >32° at the initiation of harness treatment were more likely to exhibit hip dysplasia at 3 years of age.

CONCLUSIONS

Radiographic parameters prior to the Pavlik harness could be predictors of treatment failure and DDH in the future. This study showed that AI at the initiation of treatment is associated with residual acetabular dysplasia, suggesting that radiographic assessment may be useful even considering the risks associated with radiation exposure.

Hip Morphology in Periacetabular Osteotomy (PAO) Patients Treated for Developmental Dysplasia of the Hip (DDH) as Infants Compared With Those Without Infant Treatment

BACKGROUND

A subset of patients successfully treated for developmental dysplasia of the hip (DDH) as infants have symptomatic acetabular dysplasia at skeletal maturity leading to periacetabular osteotomy (PAO). The purpose of this study was to compare femoral and acetabular morphology in PAO patients with late acetabular dysplasia after previous treatment for DDH with PAO patients who do not have a history of DDH treatment.

METHODS

A single surgeon's patients who underwent PAO between 2011 and 2021 were retrospectively reviewed. Patients previously treated for infantile DDH with a Pavlik harness, abduction brace, closed reduction and spica casting, or open reduction and spica casting were included. Patients with previous bony hip surgery were excluded. Preoperative radiographic measurements of each hip were recorded including lateral center edge angle, anterior center edge angle, and Femoro-Epiphyseal Acetabular Roof index. Computed tomography measurements included the coronal center edge angle, sagittal center edge angle, Tönnis angle, acetabular anteversion at 1, 2, and 3 o'clock, femoral neck-shaft angle, femoral version, and alpha angle. Control PAO cases without a history of DDH diagnosis or treatment were matched with the infantile DDH treatment group in a 2:1 ratio based on coronal center edge angle, age, and sex.

RESULTS

There were 21 hips in 18 patients previously treated for infantile DDH (13 patients Pavlik harness, 3 abduction brace, 1 closed reduction, and 1 open reduction). The control PAO cohort was 42 hips in 42 patients who did not have previous DDH treatment. There was no statistically significant difference in any of the recorded measurements between patients previously treated for DDH and those without previous treatment including femoral version (P=0.494), anteversion at 1 o'clock (P=0.820), anteversion at 2 o'clock (P=0.584), anteversion at 3 o'clock (P=0.137), neck-shaft angle (P=0.612), lateral center edge angle (P=0.433), Femoro-Epiphyseal Acetabular Roof index (P=0.144), and alpha angle (P=0.156).

CONCLUSIONS

Femoral and acetabular morphology is similar between PAO patients with persistent symptomatic acetabular dysplasia following DDH treatment and patients presenting after skeletal maturity with acetabular dysplasia and no previous history of DDH treatment.

LEVEL OF EVIDENCE

Level III-case-control, prognostic study.

Impact of Failed Pavlik Harness Treatment on the Outcomes Following Closed or Open Reduction in Developmental Dysplasia of the Hip

PURPOSE

To investigate the impact of failed Pavlik harness (PH) treatment on the outcomes following closed reduction (CR) or open reduction (OR) in developmental dysplasia of the hip (DDH).

METHODS

Ninety-three DDH patients treated with CR or OR were enrolled. One group of which received previous PH treatment (F group) and the other (L group) not. The clinical outcomes were evaluated according to McKay's criteria. Radiographs were evaluated for acetabular index (AI) and the degree of dislocation of the hips.

RESULTS

A higher rate of CR was found in F group (P = 0.034). Before CR/OR, the mean AI in F group was significantly lower than that in L group (P = 0.000), while at the last follow-up, the AIs in both groups were all improved. In F group, there were 7 (16.67%), 18 (42.86%) and 17 (40.48%) hips were classified as Graf type II, III and IV pathologic changes, respectively, when PH treatment started, while the corresponding data were 17 (40.48%), 17 (40.48%) and 8 (19.05%) after PH treatment (P = 0.024). At the last follow-up, no significant difference was found concerning the complications between the two groups (P > 0.05).

CONCLUSIONS

PH treatment, even if failed, may have the ability of accelerating the development of the acetabulum and increasing the rate of successful CR. Thus we advocate a trial of PH treatment for all DDH patients less than 6 months of age. Meanwhile, a close monitoring by dynamic ultrasonography is required due to the risk of AVN.

MRI Predictors of Residual Dysplasia in Developmental Dysplasia of the Hip Following Open and Closed Reduction

BACKGROUND

Following open or closed reduction for children with developmental dysplasia of the hip, there remains a significant risk of residual acetabular dysplasia which can compromise the long-term health of the hip joint. The purpose of this study was to use postoperative in-spica magnetic resonance imaging (MRI) data to determine factors predictive of residual acetabular dysplasia at short-term follow-up.

METHODS

We retrospectively reviewed 63 hips in 48 patients which underwent closed or open reduction and spica casting for developmental dysplasia of the hip. MRI performed in-spica at ∼3-week follow-up were used to assess 11 validated metrics and 2 subjective factors. Acetabular index (AI) was measured on anteroposterior pelvic radiographs at 2-year postoperative follow-up. Binary logistic regression was then used to identify variables predictive of residual dysplasia, defined as an AI greater than the 90th percentile for age based on historic normative data.

RESULTS

Average age at surgical reduction was 9.3±3.2 months. 58.7% (37/63) of reductions were open. A total of 43 (68.3%) hips demonstrated residual acetabular dysplasia at 2 years postoperatively based on normative values. In those with persistent dysplasia, patients were on average older at the time of reduction (10.0 mo±3.2 vs. 8.0 mo±2.8, P=0.010) and more likely female (88.4% vs. 60.0%, P=0.010). Patients with residual dysplasia were more likely to have mild subluxation on postoperative MRI (40.0% vs. 10.5%, P=0.022). Hips with a cartilaginous acetabular index (CAI) of >23 degrees were 7.6 times more likely to develop residual dysplasia. Type of reduction (ie, closed vs. open) did not appear to influence the rate of residual dysplasia (P=0.682).

CONCLUSION

In this series, the rate of residual dysplasia after surgical reduction was higher than most previous reports, with no appreciable difference between closed and open reductions. Older age, female sex, and a higher CAI were associated with a greater risk of persistent radiographic dysplasia. In particular, hips with a CAI >23 degrees were 7.6 times more likely to be dysplastic at 2-year follow-up.

LEVEL OF EVIDENCE

Level III.

Can Medialization of Acetabular Rim Be a Prognostic Factor in Treatment of Developmental Dysplasia of Hip?

OBJECTIVES

To investigate if acetabular rim medialization (ARM) can be used as a new parameter in determining the treatment choice and duration in Graf type III and IV hips.

METHODS

Among the 12,300 infants who underwent hip ultrasound (US) according to Graf's method between 2015 and 2019, 26 infants (9 had bilateral pathology hence 35 hips) with type III and IV hips, whose follow-up data could be obtained were included in the study. Age of the infants at the initial diagnosis, ARM measurement, the duration of harness treatment, and the treatment results were noted. To determine the extent of ARM, distance between a line that is drawn tangential to the iliac wing and acetabular rim was measured.

RESULTS

In cases with poor prognosis, ARM measurement was 6 to 8.5 mm on the right hip and 4 to 9 mm on the left hip. Bilaterality or unilaterality, left or right pathology, and gender did not have a significant effect on the prognosis (P >.05). Age at the initial diagnosis and ARM had significant effects on treatment success (P = .04, P = .00, respectively). In predicting the prognosis, ARM was found to be more successful than age (AUC = 0.95 versus AUC = 0.68). When these two variables were evaluated together, the success in predicting the prognosis significantly increased (AUC = 0.98).

CONCLUSIONS

ARM measurement may have an important role in determining the treatment method and duration in Graf type III and IV hips. It can be used as a prognostic factor alone or in combination with treatment initiation time. When the two factors are combined, prognostic value significantly increases.

Residual Acetabular Dysplasia in the Reduced Hip

BACKGROUND

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).

DISCUSSION

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.

CONCLUSION

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.

Principles of Bracing in the Early Management of Developmental Dysplasia of the Hip

Bracing is considered a gold standard in treating Developmental Dysplasia of the Hip (DDH) in infants under 6 months of age with reducible hips. A variety of braces are available that work on similar principles of limiting hip adduction and extension. This paper summarises the current evidence regarding bracing in DDH. Most of the literature pertains to the Pavlik harness (PH) and there are few studies for other brace types. Bracing eliminates dislocating forces from the hamstrings, the block to reduction of the psoas and improves the muscle line of pull to stabilise the hip joint. Recent studies have shown no benefit in bracing for stable dysplasia. The rates of PH treatment failure in Ortolani-positive hips have been reported to be high. Barlow positive hips have lower Graf grades and are more amenable to PH treatment. There is consensus that the earlier the diagnosis of DDH and initiation of PH treatment, the better the outcome. Failure rates due to unsuccessful reduction and AVN are higher with treatment initiated after age 4-6 months. Studies have shown no benefits of staged weaning of braces. While there is no maximum time in brace, current consensus suggests a minimum of 6 weeks. The key to successful bracing lies in education and communication with the family.

What is the association between MRI and conventional radiography in measuring femoral head migration?

Background and purpose - Pelvic radiographs are traditionally used for assessing femoral head migration in residual acetabular dysplasia (RAD). Knowledge of the heightened importance of cartilaginous structures in this condition has led to increased use of MRI in assessing both osseous and cartilaginous structures of the pediatric hip. Therefore, we assessed the relationship between migration percentages (MP) found on MRI and conventional radiographs. Second, we analyzed the reliability of MP in MRI and radiographs.Patients and methods - We retrospectively identified 16 patients (mean age 5 years [2-8], 14 girls), examined for RAD during a period of 2½ years. 4 raters performed blinded repeated measurements of osseous migration percentage (MP) and cartilaginous migration percentage (CMP) in MRI and radiographs. Pelvic rotation and tilt indices were measured in radiographs. Bland-Altman (B-A) plots and intraclass correlation coefficients (ICC) were calculated for agreement and reliability.Results - B-A plots for MP_R and MP_MRI produced a mean difference of 6.4 with limits of agreement -11 to 24, with higher disagreements at low average MP values. Mean MP_R differed from mean MP_MRI (17% versus 23%, p < 0.001). MP_R had the best interrater reliability with an ICC of 0.92 (0.86-0.96), compared with MP_MRI and CMP with ICC values of 0.61 (0.45-0.70) and 0.52 (0.26-0.69), respectively. Intrarater reliability for MP_R, MP_MRI and CMP all had ICC values above 0.75 and did not differ statistically significantly. Differences inMP_MRI and MP_R showed no correlation to pelvic rotation index, pelvic tilt index, or interval between radiograph and MRI exams.Interpretation - Pelvic radiographs underestimated MP when compared with pelvic MRI. We propose CMP as a new imaging measurement, and conclude that it has good intrarater reliability but moderate interrater reliability. Measurement of MP in radiographs and MRI had mediocre to excellent reliability.

Timing of Repeat Ultrasound Examination in Treatment of Stable Developmental Dysplasia of the Hip

BACKGROUND

Worldwide a wide variation exists in duration of Pavlik harness treatment for infants up to 6 months with stable developmental dysplasia of the hip (DDH). The purpose of this study was to evaluate whether shortening the time to first routine follow-up ultrasound after initiation of Pavlik harness treatment would reduce treatment duration and whether this influenced radiologic outcome at 1 year of age. Furthermore, predictors of higher acetabular index (AI) at 1 year of age were investigated.

METHODS

A retrospective study was conducted in infants with stable DDH (Graf IIb and IIc) diagnosed and treated between 2015 and 2017. Two groups were identified: first routine follow-up ultrasound at 12 weeks after Pavlik harness initiation (group I) and first routine follow-up ultrasound at 6 weeks after Pavlik harness initiation (group II). In both groups, treatment was continued until repeat ultrasound measurements (every 6 wk) showed a normalized hip. Radiologic outcome at 1 year of age was defined as residual dysplasia measured on an anteroposterior hip radiograph according to the Tönnis table.

RESULTS

A total of 222 infants were included. The median time of Pavlik harness treatment was 12 weeks (interquartile range, 11.9 to 12.3) in group I compared with 6.1 weeks (interquartile range, 6.0 to 7.5) in group II (P<0.001). Residual dysplasia at 1 year of age was detected in 20 infants (16.8%) in group I compared with 11 infants (10.7%) in group II (P=0.189). The multivariable prediction model showed that positive family history and lower baseline alpha angle correlate with a higher AI at 1 year of age.

CONCLUSIONS

First routine follow-up ultrasound can be safely brought forward from 12 to 6 weeks after Pavlik harness initiation. Furthermore, infants with a positive family history for DDH and an initial low alpha angle are at higher risk to have a higher AI at 1 year of age.

LEVEL OF EVIDENCE

Level III-retrospective study.

Is There a Benefit to Weaning Pavlik Harness Treatment in Infantile DDH?

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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 OF EVIDENCE

Level III.

Part-time Abduction Bracing in Infants With Residual Acetabular Dysplasia: Does Compliance Monitoring Support a Dose-dependent Relationship?

INTRODUCTION

Residual acetabular dysplasia is often seen after successful Pavlik treatment or during follow-up for infants with risk factors for developmental dysplasia of the hip. A previous study supported the effectiveness of part-time abduction bracing for treating this residual dysplasia. However, the relationship between time in the brace and acetabular improvement was not established given the lack of compliance data. The purpose of this prospective study was to validate the effect of part-time bracing on acetabular dysplasia and determine if a dose-dependent relationship exists.

METHODS

Eligibility criteria included infants ~6 months of age with an AP pelvic radiograph demonstrating acetabular dysplasia, defined as an acetabular index (AI) ≥30 degrees. After obtaining informed consent, a rigid abduction orthosis was prescribed with a thermal compliance sensor. Patients were instructed to wear the brace for nights/naps and follow-up at 1 year of age for repeat radiograph. AIs were measured by the senior author who was blinded to the compliance data. Hours of wear were compared with changes in AI over the study period using descriptive statistics and a generalized estimating equation model.

RESULTS

Our series consisted of 26 infants (36 hips) with a mean age at enrollment of 5.9 months (range, 4.9 to 7.9); 84.6% were female individuals. At a mean follow-up of 6 months (range, 5.1 to 8.2), average wear time/day was 11.5 hours (range, 1.3 to 21.7), and total time in brace averaged 1698 hours (range, 218 to 3244 hours). The mean improvement in AI over the study period was 4.8 degrees (95% confidence interval, 3.9-5.5 degrees). The authors found a significant correlation between average hours of brace wear per day and improvement in AI (r=0.36, P<0.05), a relationship that remained significant in our multivariate model after adjusting for confounders.

CONCLUSIONS

Part-time abduction bracing is effective for treating residual dysplasia, with the degree of improvement in AI correlating with hours of brace wear per day. Given this dose-dependent relationship, the optimal hours of wear may depend on the severity of residual dysplasia and the tolerance of the child and family to bracing.

Residual hip dysplasia in children: osseous and cartilaginous acetabular angles to guide further treatment-a pilot study

PURPOSE

In case of residual hip dysplasia (RHD) in children, pelvic radiographs are sometimes insufficient to precisely evaluate the entire coverage of the femoral head, when trying to decide on the need for further reconstructive procedures.

METHODS

This study retrospectively compares the bony and the cartilaginous acetabular angle of Hilgenreiner (HTE) of 60 paediatric hips on pelvic MRI separated in two groups. Group 1 included 31 hips with RHD defined by a bony HTE > 20°. Group 2 included 27 hips with a HTE < 20°. They were compared by introducing a new ratio calculated from the square of cartilaginous HTE above the bony HTE on frontal MRI. The normal upper limit for this acetabular angle ratio was extrapolated from the published normal values of cartilaginous HTE and bony HTE in children.

RESULTS

The acetabular angle ratio was statistically significantly increased in the hips with RHD with a mean value of 7.1 ± 4.7 compared to the hips in the control group presenting a mean value of 2.1 ± 1.9 (p < 0.00001).

CONCLUSIONS

This newly introduced ratio seems to be a helpful tool to orientate the further treatment in children presenting borderline RHD.

Ultrasound Characteristics of Clinically Dislocated But Reducible Hips With DDH

BACKGROUND

Although ultrasound (US) is frequently used in diagnosis and management of infantile developmental dysplasia of the hip, precise ultrasonographic parameters of what constitutes a dislocation, subluxation etc remain poorly defined. The purpose of this study was (1) to describe the ultrasonographic characteristics of a large cohort of clinically dislocated but reducible hips and (2) to begin to develop ultrasonographic definitions for what constitutes a hip dislocation.

METHODS

A retrospective review of prospectively collected data from an international multicenter study group on developmental dysplasia of the hip was conducted on all patients under 6 months of age with hip(s) that were dislocated at rest but reducible based on initial physical examination (ie, Ortolani positive). Femoral head coverage (FHC), alpha angle (α), and beta angle (β) were measured on pretreatment US by the individual treating surgeon, and were recorded directly into the database.

RESULTS

Based on 325 Ortolani positive hips, the median FHC on presentation was 10% with an interquartile range of 0% to 23%. A total of 126 of the 327 hips (39%) demonstrated 0% FHC. The 90th percentile was found to be at 33% FHC. Of 264 hips with sufficient α data, the median α was 43 degrees with an interquartile range from 37 to 49 degrees. The 90th percentile for α was at 54 degrees. A total of 164 hips had documented β with a median of 66 degrees and an interquartile range of 57 to 79 degrees; the 90th percentile was at 94 degrees.

CONCLUSIONS

Analysis of a large cohort of patients with dislocated but reducible hips reveals a median percent FHC of 10%, a median α of 43 degrees, and a median β of 66 degrees on initial US. Using a threshold at the 90th percentile, a sensible ultrasonographic definition of a dislocated hip seems to be FHC≤33%, implying that FHC between 34% and 50% may be reasonably termed a subluxation. Although these findings are consistent with previous, smaller reports, further prospective research is necessary to validate these thresholds.

LEVEL OF EVIDENCE

Level IV-diagnostic study.

Correlations between ultrasonographic and subsequent radiographic findings of developmental dysplasia of the hips

Purpose

The study aimed to investigate the utility of ultrasonographic (US) findings in predicting the subsequent radiographic parameters of developmental dysplasia of the hips.

Methods

In this 12-year retrospective cohort study, all new-born infants with a positive clinical examination or risk factors were included. They were scheduled for hip ultrasonography in the first 3 months, and subsequent radiographs at 1 year of life. The US images were evaluated using the Graf classification, Harcke’s dynamic screening method, and Terjesen’s femoral head coverage method. The radiographic images were evaluated using the acetabular index and femoral head position. The overall US or radiographic findings were considered abnormal if they were classified as abnormal for any of their respective parameters. The overall US and radiographic parameters were correlated.

Results

A total of 160 patients were included. The overall US and radiographic parameters showed no statistically significant difference (P=0.050). The sensitivity, specificity, and accuracy of the overall US parameters were 57.1%, 84.9%, and 81.3%, respectively. All three individual US parameters showed no statistically significant differences, with the overall radiographic findings and acetabular index (P>0.05). However, they showed a statistically significant difference, with the position of the femoral head (P<0.001), with the US parameters having an excellent negative predictive value of 100% for identifying an abnormal femoral head position.

Conclusion

The current study suggests that US findings evaluated in the first 3 months of life showed no statistically significant difference with radiographic findings evaluated at 1 year of life. The US parameters showed an excellent negative predictive value for abnormal femoral head position on radiographs.

Graf Type-IV Hips Have a Higher Risk of Residual Acetabular Dysplasia at 1 Year of Age Following Successful Pavlik Harness Treatment for Developmental Hip Dysplasia

BACKGROUND

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.

METHODS

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).

RESULTS

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).

CONCLUSIONS

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 OF EVIDENCE

Level III-therapeutic study.

Late acetabular dysplasia after successful treatment for developmental dysplasia of the hip using the Pavlik method: A systematic literature review

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).

Level of evidence

IV.

Exploration of femoral head coverage in screening developmental dysplasia of the hip in infants

PURPOSE

To investigate the relationship of femoral head coverage (FHC) with Graf's classification for diagnosis of developmental dysplasia of the hip (DDH) and its role in evaluating hip stability.

METHODS

A total of 4222 hips were screened ultrasonographically with Graf's and Harcke's methods. The stability of hips was analyzed using the difference between FHCs at neutral and flexion positions (FHC-D).

RESULTS

(1) For the non-dislocated hips, the mean value of FHC at the neutral position was 59.4%, which was significantly greater than 55.0% of FHC at the flexion position (p < 0.001). (2) FHC at the neutral position corresponding to Graf I, IIa/b, IIc, D, III, and IV was 63.0 ± 4.7%, 57.0 ± 5.2%, 49.5 ± 5.5%, 37.7 ± 3.7%, 30.2 ± 12.7%, and 7.4 ± 11.9%, respectively, and that at the flexion position was 59.0 ± 4.4%, 50.7 ± 9.4%, 35.2 ± 5.2%, 30.8 ± 1.3%, 23.4 ± 10.7%, and 4.7 ± 9.9%, respectively, showing a statistically significant difference between the two positions. (3) The AUC of FHC-D in evaluating the stability of hips was 0.972. When the threshold was 8.5%, the sensitivity, specificity, and accuracy of FHC-D in detecting hip instability were 89.0%, 93.0%, and 93.9%, respectively.

CONCLUSIONS

FHC can be used as a reference indicator for DDH classification. FHC at different positions corresponds to different reference values, and FHC-D can be used as a quantitative indicator for assessment of hip stability.

Treatment of developmental dysplasia of the hip with the Pavlik harness in children under six months of age: indications, results and failures

PURPOSE

The aim of this article is to review the current concepts in the indications, results and failure causes of the treatment of developmental dysplasia of the hip (DDH) with the Pavlik harness.

METHODS

The reported variables influencing the outcome in the Pavlik harness treatment were analyzed.

RESULTS

Significant discrepancies about the clinical and radiological outcomes, the rates of failure and complications as well as the variables influencing the treatment outcome occur in the published studies due to the heterogeneity of the data and the differences in the methods used. The overall short-, mid- or long-term success rate of the treatment ranges from 45% to 100% and it is commonly over 75%. The rate of osteonecrosis of the femoral head ranges from 1% to 30%. Age, gender, laterality, radiological or clinical severity of the initial hip pathology and parents' compliance are the commonly reported determinants of failure of the treatment.

CONCLUSION

The failure in treatment with the Pavlik harness is multifactorial, initial type of hip dysplasia being the most prominent followed by the treatment initiation age. This type of treatment cannot be considered as the best option in Graf IV hips (hip ultrasonography) or highly dislocated hips (plain radiography) and in infants older than three months of age, as the risk of failure and development of complications including osteonecrosis and femoral nerve palsy seem to increase in such circumstances. Large-scale, comparative studies including homogenous data are needed to answer the unsolved questions concerning indications.

Development of unstable hips after treatment with the Tübingen splint: mid-term follow-up of 83 hip joints

INTRODUCTION

Early diagnosis and treatment of hip dysplasia are widely accepted as major factors for beneficial outcome. However, modalities for reduction and retention as well as for imaging are currently under clinical investigation. Local and general risk factors, e.g., breech presentation and the family's desire to avoid in-hospital treatment are major concerns in the decision-making process and consultation. For treatment of unstable hips in newborns the treatment with the Tübingen splint has proven good results in recent studies. However, mid- and long-term outcome studies are missing. We report on clinical results and X-ray parameter of initially unstable hips after treatment with the Tübingen splint at two time points: 12-24 and 24-48 months of age.

MATERIALS AND METHODS

Included were newborns with 83 unstable hips (type D, III, IV according to Graf) which were successfully treated with the Tübingen splint-used as reduction splint 24 h per day/7 days per week-until type I hips were documented by ultrasound examination. Measurments are based on routine pelvic X-ray control at the age of 12-24 and 24-48 months. The acetabular angle was determined and according to the Tönnis-Classification evaluated into: normal findings (< 1 s), slightly dysplastic findings (1-2 s) and severely dysplastic findings (> 2 s). Children with secondary hip dysplasia were not included in this series.

RESULTS

In 2nd year of life, 45 hips (54.2%; initial hip type D: 47.4%, III: 63.2%, IV: 42.9%) of the formerly unstable hips show normal X-ray findings. Although final ultrasound showed normal findings, at this time point 28 hips (33.7%; initial hip type D: 34.2%, III: 31.6%, IV: 42.9%) were slightly dysplastic and 10 (12.0%%; initial hip type D: 18.4%, III: 5.3%, IV: 14.3%) still severely dysplastic. At the age of 24-48 months, the percentage of radiologic normal hips had increased to 61 hips (73.5%; initial hip type D: 68.4%, III: 81.6%, IV: 57.1%), the number of slightly (19 hips) and severely dysplastic (3 hips) hips had decreased 22.9% (initial hip type D: 28.9%, III: 15.8%, IV: 28.6%) respectively 3.6% (initial hip type D: 2.6%, III: 2.6%, IV: 14.3%). At this time no operative intervention was neccessary.

CONCLUSIONS

Our mid-term data show on the one hand a good development of unstable hips after successful treatment with the Tübingen splint. On the other hand despite successful therapy and normal ultrasound findings at the end of treatment further imaging by X-ray are mandatory to close follow-up and to detect those which might need surgical correction of residual dysplasia.

The pubo-femoral distance decreases with Pavlik harness treatment for developmental dysplasia of the hip in newborns

OBJECTIVE

To evaluate the evolution of the ultrasonographic pubo-femoral distance (PFD) before and after Pavlik harness treatment for developmental dysplasia of the hip (DDH) in newborns.

PATIENTS AND METHODS

Twenty-five patients (16.7 ± 10.4 days; 19 females, six males) diagnosed with DDH and treated using the Pavlik harness were included. Eighteen patients had bilateral, and seven unilateral DDH, with a total of 43 dysplastic hips. The seven non-dysplastic hips in unilateral cases were used for comparison. The PFD was measured in the coronal and axial planes with the hip flexed to approximately 90°, before and after an average of 93 days of treatment. The femoral head coverage was assessed in the coronal plane, and correlated with PFD values.

RESULTS

In dysplastic hips, the mean PFD decreased from 6.1 ± 1.8 mm to 3.0 ± 0.7 mm in the axial (adjusted difference, 2.9 mm; p < 0.01), and from 5.9 ± 2.0 to 3.0 ± 0.6 mm in the coronal plane (adjusted difference 2.7 mm; p < 0.01). The femoral head coverage increased from 30.8 to 62.1%, and the mean differences of femoral head coverage and PFD were significantly correlated (p < 0.001). There was no difference between treated dysplastic and non-dysplastic hips. There was high intra- and inter-observer agreement for PFD measurements.

CONCLUSION

The PFD decreased significantly after DDH treatment using the Pavlik harness in newborns, and showed significant correlation with the femoral head coverage improvement. PFD might be a reliable tool for monitoring DDH treatment in newborns treated using the Pavlik harness.

A Reliable and Valid Objective Structured Assessment of Technical Skill for the Application of a Pavlik Harness Based on International Expert Consensus

BACKGROUND

The use of competency-based training is increasing in medical education as it offers individualized learning opportunities to master required skills. Inherent to this method of teaching is the need for standardized and objective assessments of skill mastery. In orthopaedic surgery, educational programs have focused on surgical skills with lesser emphasis on nonoperative techniques. Accordingly, formal evaluation tools specific to Pavlik Harness application do not exist, despite its widespread use and potential complications from inappropriate application. This study sought to develop a reliable and valid evaluation tool based on international expert consensus to standardize and evaluate Pavlik Harness application for developmental dysplasia of the hip.

METHODS

Consensus was sought from 10 content experts using Delphi methodology. Resulting items formed the Objective Structured Assessment of Technical Skill (OSATS). Thirty-five participants were selected into 3 a priori groups (expert, intermediate and novice) based on Pavlik Harness experience. On 2 occasions, 3 content experts assessed randomized and deidentified videotapes of each participant applying a Pavlik Harness to an infant model using the OSATS and global rating scales (GRS). The reliability and validity of the OSATS was determined with intraclass (ICC) and Pearson correlations and analysis of variance (ANOVA).

RESULTS

Consensus was obtained after 2 rounds of structured surveying and resulted in a 25-item OSATS. The reliability of the OSATS was excellent with an ICC of 0.96 for interrater and 0.98 for test-retest reliability. Construct validity was excellent with high correlations between OSATS and GRS (>0.90). In addition, the OSATS discriminated between expert, intermediate, and novice users.

CONCLUSIONS

We have developed a competency-based evaluation tool for Pavlik Harness application based on consensus from international experts. The OSATS has been shown to be a reliable and valid method for assessing Pavlik Harness application that can discriminate between expert, intermediate, and novice users.

LEVEL OF EVIDENCE

Level II.

Intraoperative Arthrogram Predicts Residual Dysplasia after Successful Closed Reduction of DDH

OBJECTIVE

To determine the incidence of residual dysplasia after closed reduction (CR) of developmental dysplasia of the hip (DDH) and assess correlations between quality of arthrogram-guided CR and residual dysplasia using a new intraoperative radiographic criterion.

METHODS

Data of a consecutive series of 126 patients with DDH in 139 hips treated at our institution by arthrogram-guided CR from March 2006 to June 2013 were reviewed in this retrospective study. There were 23 boys and 103 girls with 88 affected left hips and 51 right hips. The average age at closed reduction was 14 months (range, 7-19 months) and average duration of follow-up 36 months (range, 24-100 months). Femoral head coverage (FHC) and arthrography type (A/B/C) on best reduced arthrographic images, acetabular index (AI) and Wiberg Center-Edge (CE) angle on anteroposterior (AP) pelvis radiograph at latest follow-up were measured. Residual hip dysplasia was determined according to the Harcke acetabular dysplasia radiographic standard. Patients were divided into non-late acetabular dysplasia (non-LACD) and late acetabular dysplasia (LACD) groups according to final results and age at reduction, sex and side compared between these two groups. Correlations between FHC and arthrography type and residual hip dysplasia were analyzed. Multiple logistic regression analysis was used to analyze sex, AI at CR, arthrography type and FHC with LACD. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff value for FHC.

RESULTS

Forty-five of 139 hips (32.4%) had residual hip dysplasia. Avascular necrosis of the femoral head occurred in 11 hips (7.9%), nine of which had acetabular dysplasia. There were no significant differences between the two groups in age at reduction, sex or side. FHC differed significantly between the two groups (51.2% ± 15.3% vs . 28.5% ± 15.9%, t = 4.718, P = 0.000). A significantly greater percentage of the arthrography Type C group than Type A and B groups had LACD (χ(2) = 17.170, P = 0.017). According to multiple logistic regression analysis, FHC was the only prognostic factor for LACD. There was a clear cutoff value for FHC (30%), under which 81.8% hips were determined as having LACD according to ROC curve analysis.

CONCLUSIONS

Intraoperative arthrogram-determined FHC is an alternative predictor of residual hip dysplasia after CR of DDH and FHC ≤30% can be considered the criterion for unacceptable reduction.

Higher Pavlik Harness Treatment Failure Is Seen in Graf Type IV Ortolani-positive Hips in Males

BACKGROUND

Patients with developmental dysplasia of the hip (DDH) whose hips are dislocated but reducible (Ortolani positive) are more likely to experience Pavlik harness treatment failure than are patients with dysplastic and reduced but dislocatable (Barlow positive) hips. However, data regarding factors associated with failure are limited and conflicting.

QUESTIONS/PURPOSES

We asked: (1) What is the frequency of Pavlik harness treatment failure among Ortolani-positive hips, Barlow-positive hips, and dysplastic hips? (2) What are the factors predictive of failure of Pavlik harness treatment for Ortolani-positive hips?

METHODS

In this retrospective study we identified 150 patients who underwent the Pavlik harness method for treatment of DDH between August 2011 and July 2015. Six patients initially treated at an outside facility, four patients with associated conditions, and three who pursued treatment elsewhere were excluded. A total of 137 patients (215 hips) with a median age at the time of Pavlik placement of 30 days (range, 4-155 days) were included. Of the 215 hips, 78 (36.3%) were Ortolani positive, 60 (27.9%) were Barlow positive, and 77 (35.8%) were stable, with the diagnosis of dysplasia made on ultrasound. All patients were treated with the Pavlik harness method. The primary outcome was failure of the Pavlik harness to achieve and maintain concentric hip reduction assessed by examination and ultrasound. All patients were followed after completion of Pavlik treatment for a minimum of 2 months (mean, 3 months; range, 2-4 months). In addition, 90% (122 of 137) of the patients were followed for a minimum of 6 months. Patient-specific data including family history, breech versus cephalic presentation at birth, age, sex, laterality, and hip abduction were recorded. Ultrasound data at the time of diagnosis included Graf classification, alpha angle, and percentage of femoral head coverage.

RESULTS

The Pavlik harness method failed in 27% (21 of 78) of hips that were Ortolani positive, 8% (six of 77) with dysplasia, and 5% (three of 60) that were Barlow positive. After controlling for potential confounding variables, such as range of hip abduction, male sex (adjusted odds ratio [OR], 6.9; 95% CI, 2.0-24.2; p = 0.002) and Graf Type IV ultrasound classification (dislocated hip with alpha angle less than 43° and labrum displaced downward) (OR, 4.4; 95% CI, 1.3-15.4; p = 0.019) were identified as independent predictors of failure of Pavlik treatment among Ortolani-positive hips.

CONCLUSIONS

Ultrasound imaging of the hip should be part of the initial assessment for Ortolani-positive hips, as the ultrasound classification was found to have prognostic implications. Parents of male infants with Graf Type IV hips should be counseled regarding the higher risk of Pavlik failure. Future well-designed prospective controlled studies are necessary to establish whether alternative strategies to the Pavlik harness might improve the early outcomes of DDH in males with Graf Type IV hips.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Risk factors for avascular necrosis after closed reduction for developmental dysplasia of the hip

PURPOSE

The purpose of this study was to identify and evaluate risk factors of avascular necrosis (AVN) after closed treatment for developmental dysplasia of the hip (DDH).

METHODS

A retrospective review of children diagnosed with DDH at a tertiary-care children's hospital between 1986 and 2009 was performed. The presence of AVN was assessed according to Salter's classification system.

RESULTS

Eighty-two affected hips in 70 children with an average age of 10 months at closed reduction (range 1-31 months) and 5 years (range 2-19 years) of follow-up met the inclusion criteria. Twenty-nine (of 82, 35 %) affected hips developed AVN. The use of pre-reduction traction (p = 0.019) increased the risk of AVN, while preoperative Pavlik harness or brace trial (p = 0.28), presence of ossific nucleus at the time of closed reduction (p = 0.16), and adductor tenotomy (p = 0.37) were not significant factors. Laterality (right vs. left) was also not a significant risk factor (p = 0.75), but patients who underwent closed reduction for bilateral DDH were less likely to develop AVN (p = 0.027). Overall, the degree of abduction did not affect the rate of AVN (p = 0.87). However, in patients treated with closed reduction younger than 6 months of age, the rate of AVN was increased with abduction ≥50° (9/15, 60 %) compared to abduction <50° (0/8, 0 %) (p = 0.007). Patients who developed AVN were more likely to require subsequent surgery (p = 0.034) and more likely to report a fair/poor clinical outcome (p = 0.049).

CONCLUSIONS

The risk of AVN (35 %) following closed reduction and spica casting for DDH is high. The degree of abduction in spica casts appears to be a risk factor in patients ≤6 months old. The authors recommend that abduction in spica casts should be limited to <50° in children younger than 6 months of age.

LEVEL OF EVIDENCE

IV.

Success of Pavlik Harness Treatment Decreases in Patients ≥ 4 Months and in Ultrasonographically Dislocated Hips in Developmental Dysplasia of the Hip

BACKGROUND

Treatment of developmental dysplasia of the hip (DDH) using the Pavlik harness has been a widely used method in patients between 0 and 6 months of age for many years. However, the factors influencing the success rate of this treatment modality have still not exactly been determined as a result of the limited number of clinical studies with higher level of evidence.

QUESTIONS/PURPOSES

We, therefore, asked whether (1) patient-related variables such as age, gender, and laterality; coexisting risk factors including family history, breech presentation, intrauterine packing, first-born girl, oligohydroamnios, and swaddling; and (2) the severity of hip dysplasia, defined by ultrasonography, are associated with differences in the success rate of Pavlik harness treatment in infants with DDH.

METHODS

Between 2012 and 2014, we treated 153 children (≤ 6 months of age) with DDH using the Pavlik harness. Hip dysplasia apart from coexisting neuromuscular disorders, congenital abnormalities, or syndromes was our inclusion criteria. Of patients thus treated, 130 (85%) were available for the evaluation of patient- and hip-related variables against the success of Pavlik harness treatment. Mean age of these patients on day of diagnosis and initiation of treatment was 108 days. The diagnostic and followup examinations of the hips were made by ultrasonography using Graf's method. Pavlik harness treatment was initiated in Graf Type IIa- and worse hips and treatment was considered "successful" when a Graf Type I hip was achieved. Pavlik harness treatment was successful in 92 (71%) patients (130 of 181 hips [72%]).

RESULTS

Age was the only patient-related variable influencing the success rate of the treatment; the mean age of children in whom Pavlik harness treatment succeeded (97 ± 38 days; 95% confidence interval [CI], 90-112) was lower than the age of those who failed (135 ± 37 days; 95% CI, 123-147; p < 0.001). The highest success rate was obtained in children younger than age 3 months (37 of 40 [93%]) and the lowest one older than age 5 months (nine of 24 [37%]) (p < 0.001). The threshold age value related to an increased risk of failure was found to be 4 months and older, which had a sensitivity of 66% and a specificity of 77% (p < 0.001). A higher initial α angle was observed in the hips in which the treatment succeeded (53° ± 6°; 95% CI, 51°-53°) than in those that failed (47° ± 7°; 95% CI, 45°-50°; p < 0.001). The threshold α angle value related to an increased risk of treatment failure was 46° and less, which had a sensitivity of 47% and a specificity of 86% (p < 0.001). Dislocated hips (Graf Type III and IV hips) had the lowest rate of treatment success (five of 19 [26%] and two of four [50%], respectively), whereas Graf Type IIa- hips had the highest (27 of 29 [93%]) (p < 0.001).

CONCLUSIONS

We conclude that Pavlik harness treatment is less effective in children at and over the age of 4 months at the time the harness is first applied as well as in hips with complete dislocations and hips with severely deficient acetabular bony roofs. In such older patients and worse hip types, the use of initial Pavlik harness treatment needs to be revisited. Future studies, comparing the outcomes of the Pavlik harness treatment and other types of interventions in such patients and hip types, are needed.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Developmental dysplasia of the hip: What has changed in the last 20 years?

Developmental dysplasia of the hip (DDH) describes the spectrum of structural abnormalities that involve the growing hip. Early diagnosis and treatment is critical to provide the best possible functional outcome. Persistence of hip dysplasia into adolescence and adulthood may result in abnormal gait, decreased strength and increased rate of degenerative hip and knee joint disease. Despite efforts to recognize and treat all cases of DDH soon after birth, diagnosis is delayed in some children, and outcomes deteriorate with increasing delay of presentation. Different screening programs for DDH were implicated. The suspicion is raised based on a physical examination soon after birth. Radiography and ultrasonography are used to confirm the diagnosis. The role of other imaging modalities, such as magnetic resonance imaging, is still undetermined; however, extensive research is underway on this subject. Treatment depends on the age of the patient and the reducibility of the hip joint. At an early age and up to 6 mo, the main treatment is an abduction brace like the Pavlik harness. If this fails, closed reduction and spica casting is usually done. After the age of 18 mo, treatment usually consists of open reduction and hip reconstruction surgery. Various treatment protocols have been proposed. We summarize the current practice for detection and treatment of DDH, emphasizing updates in screening and treatment during the last two decades.

Radiographic Follow-up of DDH in Infants: Are X-rays Necessary After a Normalized Ultrasound?

BACKGROUND

Concerns about radiation exposure have created a controversy over long-term radiographic follow-up of developmental dysplasia of the hip (DDH) in infants who achieve normal clinical and ultrasonographic examinations. The purpose of this study was to assess the importance of continued radiographic monitoring by contrasting the incidence of residual radiographic dysplasia to the risks of radiation exposure.

METHODS

We reviewed a consecutive series of infants with idiopathic DDH presenting to our institution over 4 years. Infants with "normalized DDH" had achieved a stable clinical examination with an ultrasound revealing no signs of either hip instability or acetabular dysplasia. We excluded infants with persistently abnormal ultrasonographic indices, clinical examinations, or both by 6 months of age, including those requiring surgical reduction. Anteroposterior pelvic radiographs at approximately 6 and 12 months of age were then evaluated for evidence of residual radiographic acetabular dysplasia. Radiation effective dose was calculated using PCXMC software.

RESULTS

We identified 115 infants with DDH who had achieved both normal ultrasonographic and clinical examinations at 3.1±1.1 months of age. At the age of 6.6±0.8 months, 17% of all infants demonstrated radiographic signs of acetabular dysplasia. Of infants left untreated (n=106), 33% had dysplasia on subsequent radiographs at 12.5±1.2 months of age. No significant differences were evident in either the 6- or 12-month rates of dysplasia between infants successfully treated with a Pavlik harness and infants normalizing without treatment but with a history of risk factors (P>0.05). The radiation effective dose was <0.01 mSv for the combined 6- and 12-month single-view anteroposterior radiographs of the pelvis.

CONCLUSIONS

The notable incidences of radiographic dysplasia after previous DDH normalization in our study cohort appear to outweigh the risks of radiation exposure. Our findings may warrant radiographic follow-up in this population of infants through at least walking age to allow timely diagnosis and early intervention of residual acetabular dysplasia.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Ultrasound for Infants at Risk for Developmental Dysplasia of the Hip

The best screening method for developmental dysplasia of the hip is controversial. Ultrasonography is sensitive, but cost-effectiveness may limit its use. This study assessed whether ultrasound screening would increase in effectiveness if targeted toward infants with established risk factors for developmental dysplasia of the hip and normal findings on physical examination. All ultrasound scans performed at the authors' institution from January 2007 through January 2011 to screen for developmental dysplasia of the hip were reviewed. Infants with risk factors for developmental dysplasia of the hip and normal findings on physical examination by orthopedic faculty or a pediatrician were selected. Of the 530 cases that were reviewed, 217 had risk factors for developmental dysplasia of the hip and normal findings on physical examination. Mean age of the 217 selected patients was 6.9 weeks. Of the patients, 83% were female, 77% had breech presentation, 30% were firstborn children, 13% had intrauterine packaging abnormalities, and 3% had a family history of developmental dysplasia of the hip. Of the 217 infants, 44 had 1 risk factor, 121 had 2 risk factors, 46 had 3 risk factors, and 6 had 4 risk factors. Dynamic ultrasound evaluation showed instability in 17 patients, for a 7.8% incidence of developmental dysplasia of the hip. All 17 patients were treated with a Pavlik harness. The results suggested that selective ultrasound screening may be effective in infants with risk factors and normal findings on physical examination. Selective ultrasound screening changed treatment management in almost 8% of patients and clinical follow-up in 6.5%. Analysis of the cost-effectiveness of screening is needed.

Factors associated with an unfavourable outcome after Salter innominate osteotomy in patients with unilateral developmental dysplasia of the hip: does occult dysplasia of the contralateral hip affect the outcome?

Salter innominate osteotomy is an effective reconstructive procedure for the treatment of developmental dysplasia of the hip (DDH), but some children have a poor outcome at skeletal maturity. In order to investigate factors associated with an unfavourable outcome, we assessed the development of the contralateral hip. We retrospectively reviewed 46 patients who underwent a unilateral Salter osteotomy at between five and seven years of age, with a mean follow-up of 10.3 years (7 to 20). The patients were divided into three groups according to the centre-edge angle (CEA) of the contralateral hip at skeletal maturity: normal (> 25°, 22 patients), borderline (20° to 25°, 17 patients) and dysplastic (< 20°, 7 patients). The CEA of the affected hip was measured pre-operatively, at eight to nine years of age, at 11 to 12 years of age and at skeletal maturity. The CEA of the affected hip was significantly smaller in the borderline and dysplastic groups at 11 and 12 years of age (p = 0.012) and at skeletal maturity (p = 0.017) than in the normal group. Severin group III was seen in two (11.8%) and four hips (57.1%) of the borderline and dysplastic groups, respectively (p < 0.001). Limited individual development of the acetabulum was associated with an unfavourable outcome following Salter osteotomy.

Developmental dysplasia of the hip in neonates: evolution of acetabular dysplasia after hip stabilization by brief Pavlik harness treatment

BACKGROUND

The recommended treatment duration in neonates with developmental dysplasia of the hip (DDH) varies depending on whether prolonged Pavlik harness therapy is believed to favourably affect the course of the acetabular dysplasia. According to one theory, several months of additional Pavlik harness therapy after achieving hip reduction contributes to correct the acetabular dysplasia. Another theory holds that hip dislocation induces the acetabular dysplasia, which corrects spontaneously once the femoral head is properly seated in the acetabulum. Here, we evaluated this second theory by studying outcomes after early brief Pavlik harness therapy.

HYPOTHESIS

Acetabular dysplasia associated with neonatal hip instability undergoes self-correction provided stable hip reduction is achieved very early after birth. Therefore, the duration of Pavlik harness therapy can be substantially shortened.

MATERIALS AND METHODS

We defined hip instability as either reducible hip dislocation or a very easily dislocatable hip with a soft clunk precluding determination of spontaneous hip position as dislocated or reduced. Static and dynamic ultrasound scans were obtained. Patients with ultrasonographic instability (pubo-femoral distance>5mm with less than 50% of coverage) underwent a second physical examination and received treatment. We re-evaluated 42 abnormal hips in 30 patients after a mean follow-up of 6.7 years (range, 5-14 years). Mean age at treatment initiation was 5 days (range, 1-15 days) and mean treatment duration was 34 days (range, 15-75 days).

RESULTS

Mean acetabular angle was 20° (range, 12°-30°) and mean Wiberg's lateral centre-edge angle was 30° (range, 22°-35°). Blunting of the lateral angle of the bony roof was noted in 8 hips at last follow-up. In 1 patient whose hip was stable clinically but unstable by ultrasonography at 21 days of age, recurrent dislocation occurred at 5 months of age. The Severin class was 1a in all patients.

DISCUSSION

Despite continuing controversy about whether hip dislocation induces dysplasia or vice versa, the need for early treatment is universally recognised. The optimal treatment duration, however, remains debated. Proponents of the familial determinism of DDH consider that acetabular shaping is genetically programmed when the femoral head is centred in the acetabular socket. Others advocate routine prolongation of Pavlik harness therapy for 2 months or longer, based on the opinion that this strategy decreases the dislocation recurrence rate and that mechanical hip unloading may promote correction of the dysplasia. Mean treatment duration in our population was 34 days and our sole objective was to treat the instability. The hip was reduced and held in its proper position long enough to allow sufficient capsule and ligament tightening to stabilise the hip. Under these conditions, the acetabular dysplasia underwent self-correction that was not related to treatment duration.

CONCLUSION

Very early Pavlik harness therapy to ensure rapid hip reduction and stabilisation optimises the potential of the acetabulum for spontaneous remodelling.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Abduction bracing for residual acetabular dysplasia in infantile DDH

BACKGROUND

Abduction bracing is often used to treat residual acetabular dysplasia in infants whose acetabular indices (AI) exceed 30 degrees after 6 months of age. However, little data exist to support this practice. The purpose of this study was to determine the efficacy of part-time abduction bracing in treating residual acetabular dysplasia by comparing a cohort of braced infants with a cohort of unbraced infants.

METHODS

We performed a retrospective review of a consecutive series of patients with developmental dysplasia of the hip (DDH) treated at our institution over 4 years. Children with stable, treated DDH but residual acetabular dysplasia at 6 months of age were identified; those with available anteroposterior pelvic radiographs at 6 months and 1 year of age were included. Patients who required open surgical reduction and those with syndromic or neuromuscular diagnoses were excluded. On the basis of practice variations at our institution, some orthopaedists start bracing when the 6-month radiograph demonstrates an AI≥30 degrees, whereas others do not; we compared these 2 cohorts. Braced patients were instructed to wear an abduction orthosis during nights and naps until follow-up at 1 year of age. The AI at 6 months and 1 year of age for both cohorts were then measured by a single observer and the differences compared.

RESULTS

Seventy-six hips in 52 patients were identified with residual dysplasia on the 6-month radiograph. Thirty-nine hips (27 patients) were unbraced, 31 hips (21 patients) were braced, and 6 hips (4 patients) were excluded for cross-over. Over a 6-month period, the braced cohort had significantly better improvement in the AI of 5.3 degrees (95% confidence interval, 4.3 to 6.3 degrees) compared to the unbraced cohort which had an improvement in the AI of only 1.1 degrees (95% confidence interval 0.6 to 1.6 degrees) (P<0.001).

CONCLUSIONS

In this comparative analysis of infants with residual acetabular dysplasia treated with abduction bracing or observation, part-time bracing significantly improved the acetabular index between 6 and 12 months of age. Part-time use of an abduction orthosis is effective for improving residual acetabular dysplasia in infants with DDH.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

High failure rate of the Pavlik harness in dislocated hips: is it bilaterality?

BACKGROUND

The purpose of this study was to evaluate the efficacy of Pavlik harness treatment in patients with bilaterally dislocated Graf type IV hips and compare them to cases with unilaterally dislocated hips.

METHODS

Twenty-one patients (42 hips) who presented with bilaterally dislocated hips with no prior treatment were studied. The comparison group consisted of 33 patients (33 hips) with unilateral hip dislocation treated with the same protocol. Successful treatment was defined as relocation of the hips within 3 weeks of Pavlik harness application.

RESULTS

Twelve of 21 patients (57%) in the bilateral group (6 failed bilaterally, 6 unilaterally) and 18/33 patients (54.5%) in the unilateral group failed harness treatment.

CONCLUSIONS

The use of the Pavlik harness in dislocated hips is associated with a high failure rate. Patients presenting with bilaterally dislocated hips however, are at no greater risk for failure than patients presenting with unilateral hip dislocation.

LEVEL OF EVIDENCE

Level III.

The Pavlik method: a systematic review of current concepts

We present a systematic review of the use of the Pavlik method in developmental dysplasia of the hip. Our aims were to evaluate treatment protocols, reported results and factors associated with successful outcomes. We found 218 relevant citations, of which 62 fulfilled our inclusion criteria. Our results have shown satisfactory clinical and radiological outcomes with the use of the harness at long-term follow-up. However, failures of harness use have been reported along with episodes of avascular necrosis. Ultrasound plays a key role in the early detection of such cases. Alternative methods of splintage have been described but larger comparative studies are required to change current practice.

Developmental dysplasia of the hip in the newborn: A systematic review

Developmental dysplasia of the hip (DDH) denotes a wide spectrum of conditions ranging from subtle acetabular dysplasia to irreducible hip dislocations. Clinical diagnostic tests complement ultrasound imaging in allowing diagnosis, classification and monitoring of this condition. Classification systems relate to the alpha and beta angles in addition to the dynamic coverage index (DCI). Screening programmes for DDH show considerable geographic variation; certain risk factors have been identified which necessitate ultrasound assessment of the newborn. The treatment of DDH has undergone significant evolution, but the current gold standard is still the Pavlik harness. Duration of Pavlik harness treatment has been reported to range from 3 to 9.3 mo. The beta angle, DCI and the superior/lateral femoral head displacement can be assessed via ultrasound to estimate the likelihood of success. Success rates of between 7% and 99% have been reported when using the harness to treat DDH. Avascular necrosis remains the most devastating complication of harness usage with a reported rate of between 0% and 28%. Alternative non-surgical treatment methods used for DDH include devices proposed by LeDamany, Frejka, Lorenz and Ortolani. The Rosen splint and Wagner stocking have also been used for DDH treatment. Surgical treatment for DDH comprises open reduction alongside a combination of femoral or pelvic osteotomies. Femoral osteotomies are carried out in cases of excessive anteversion or valgus deformity of the femoral neck. The two principal pelvic osteotomies most commonly performed are the Salter osteotomy and Pemberton acetabuloplasty. Serious surgical complications include epiphyseal damage, sciatic nerve damage and femoral neck fracture.

The early detection and management of unstable concentric closed reduction of DDH with percutaneous K-wire fixation in infants 6 to 12 months of age

BACKGROUND

In some infants with developmental dysplasia of the hip, concentric closed reduction, although initially achievable, cannot be maintained even by casting because of a deficient posterior acetabular wall. Usually, these hips will redislocate in the cast and a rereduction will be necessary, often requiring an open reduction subsequently.

METHODS

A 3-year retrospective review of 88 infants, (M/F; 14/74) 6 to 12 months of age with 124 dislocated hips, was conducted to assess the efficacy of percutaneous Kirschner wire fixation in achieving permanent hip stability. A "hip-at-risk" instability test was developed to detect potentially unstable hips at the time of closed reduction that might redislocate in the hip spica cast, and these hips were stabilized with a percutaneous K-wire through the greater trochanter into the pelvic bone.

RESULTS

The hip instability test was positive in 27 hips and negative in 97. Percutaneous K-wire fixation was used to stabilize 21 hips with a positive hip instability test. All 21 unstable hips that were stabilized with the K-wire technique maintained their concentric reduction and went on to stable development. No K-wire breakage was encountered and only 1 superficial pin tract infection occurred.

CONCLUSIONS

K-wire stabilization of unstable closed reductions is a safe, reliable technique for maintaining concentric hip reduction in infants 6 to 12 months of age with developmental dislocation of the hips.

LEVEL OF EVIDENCE

Level II retrospective study.

Bilaterally dislocated hips treated with the Pavlik harness are not at a higher risk for failure

BACKGROUND

The purpose of this study is to evaluate the efficacy of the Pavlik harness treatment in patients with bilaterally dislocated hips, and to compare them with cases with unilaterally dislocated hips.

METHODS

Twenty-nine patients (58 hips) were identified who presented with bilateral dislocated hips with no earlier treatment and received dynamic ultrasound examination. The comparison group consisted of 38 patients (38 hips) with unilateral hip dislocation treated with the same protocol. Successful treatment was defined as relocation/reduction of the hips within 3 weeks of Pavlik harness application.

RESULTS

Seventeen of 29 patients (59%) in the bilateral group (7 bilateral, 10 unilateral) and 22 of 38 patients (58%) in the unilateral group failed the harness treatment. There was no difference in the duration of harness wear for successful patients regardless of presentation.

CONCLUSIONS

Patients presenting with bilaterally dislocated hips treated with the Pavlik harness are at no greater risk for failure than patients presenting with unilateral hip dislocation.

LEVEL OF EVIDENCE

Level 3.

Ultrasonographic findings in hips with a positive Ortolani sign and their relationship to Pavlik harness failure

BACKGROUND

In developmental dysplasia, Pavlik harness treatment of hips with a positive Ortolani sign fails in up to 40% of such patients; however, no study has described factors for failure associated with ultrasonographic parameters. The goal of this study was to describe unique ultrasonographic markers in hips with a positive Ortolani sign that are associated with Pavlik harness failure.

METHODS

A retrospective review was performed of all patients less than six months old who were treated for developmental dysplasia of the hip with a Pavlik harness from 1991 to 2005 at a single institution. Inclusion criteria for this study were patients with a hip that was dislocated but reducible (a positive Ortolani sign), treatment with a Pavlik harness, and an ultrasound examination performed within four weeks after the initiation of treatment. The initial coronal ultrasound studies were graded with use of the Graf classification, the percentage of femoral head coverage, labral morphology, and two new measurements: superior femoral head displacement relative to the labrum and total femoral head displacement.

RESULTS

Eighty-five patients with 115 hips fitting the inclusion criteria were identified. Pavlik harness treatment was successful in seventy-two hips (63%) and failed in forty-three hips (37%). Increased beta angle, decreased femoral head coverage, an inverted labrum, decreased superior femoral head displacement relative to the labrum, and decreased total femoral head displacement were significantly correlated with Pavlik harness failure (p < 0.001 for all). A finding of 0 degrees of superior femoral head displacement relative to the labrum was seen in 98% of the hips with successful Pavlik harness treatment. Total femoral head displacement of less than -30 degrees was found in 89% of the hips with a failure of Pavlik harness treatment.

CONCLUSIONS

We identified two new objective measurements on static ultrasound examinations of the hip that are associated with the outcome of Pavlik harness treatment in patients with developmental dysplasia and a positive Ortolani sign. A femoral head positioned below the labrum is strongly associated with success of the Pavlik harness treatment, whereas a hip with a femoral head that is located substantially superior and lateral to the labrum is associated with Pavlik harness treatment failure. The presence of a deficient cartilaginous anlage and an inverted labrum may provide a pathoanatomical explanation for Pavlik harness treatment failure.