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

Residual Acetabular Dysplasia at Walking Age: A Study of 470 Hips Treated With Pavlik Harness

BACKGROUND

This study aims to report on the acetabular indices of walking age children following successful DDH treatment with Pavlik harness and investigate risk factors for residual acetabular dysplasia (RAD).

METHODS

We retrospectively reviewed the data for children treated for DDH at a single centre between 2015 and 2020. Acetabular indices (AI) measured on pelvic radiographs taken at 2- and 4-year follow-up visits were referenced against age-matched and sex-matched normal data. Values ≥90th percentile were considered to represent RAD.

RESULTS

A total of 305 children with 470 hips were suitable for inclusion. The mean age at treatment initiation was 7.0±4.5 weeks and mean treatment duration was 15.9±4.3 weeks. Overall, 27% and 19% of hips were found to have RAD at 2- (n=448) and 4-year (n=206) follow-up, respectively. The χ2 test for independence demonstrated that the difference in the proportion of hips with RAD at both time points was significant (P=0.032). Patients with RAD at 2 years were found to have been treated for longer (P=0.028) and had lower alpha angles on final ultrasound assessment (P<0.001). Patients with RAD at 4 years were older at initiation of treatment (P=0.041), had lower alpha angles on final ultrasound assessment (P<0.001) and were more likely to have had RAD at 2 years (P<0.001). Multivariate analysis identified lower alpha angles on final ultrasound to be predictive for RAD at 2 years (P=0.011), and presence of RAD at 2 years to be predictive for RAD at 4 years (P<0.001).

CONCLUSIONS

The risk of RAD beyond walking age in children successfully treated with Pavlik harness is not negligible. However, we observed that a significant proportion of children with RAD at 2-year follow-up had spontaneously improved without any intervention. This data suggests that routine long-term radiologic follow-up of children treated with Pavlik harness is necessary, and surgical intervention to address RAD should be delayed until at least 4 years of age.

LEVEL OF EVIDENCE

Level III-case-control study.

Incidence, Prevalence, Risk Factors, and Clinical Treatment for Children with Developmental Dysplasia of the Hip in Saudi Arabia. A Systematic Review

BACKGROUND

Developmental dysplasia of the hip (DDH) leads to pain, joint instability, and early degenerative joint disease. Incidence, prevalence, and management strategies of DDH have been well-documented in several countries, but not in Saudi Arabia.

OBJECTIVE

We synthesized the current evidence regarding incidence, prevalence, risk factors, and clinical treatment for children with DDH in Saudi Arabia.

METHODS

We searched 3 databases to locate studies. Studies that included children with DDH in Saudi Arabia; reported either incidence rate, prevalence, risk factors, and/or clinical practice; and were available in English or Arabic were included. We excluded reviews, case studies, or animal studies. Two independent authors reviewed potential studies and assessed study's quality.

RESULTS

Our search yielded 67 potential studies, of which 16 studies were included (total DDH sample = 3,127; age range = 2.5 to 86.4 months). Three studies reported incidence rates ranging from 3.1 to 4.9 per 1000 births, and 3 studies reported prevalence ranging from 6 to 78%. Nine studies reported that female sex, breech position, family history, and age less than 3 years were risk factors associated with DDH. Four studies reported that brace applications and closed reduction were conservative treatments, and 9 studies reported that open hip reduction, adductor tenotomy, and/or pelvic osteotomy were surgical approaches to treat DDH.

CONCLUSIONS

In Saudi Arabia, the Incidence and prevalence rates of DDH are 3.1 to 4.9 per 1,000 births, and 6-78%, respectively (differ from what has been reported in other countries), but the risk factors of DDH in Saudi Arabia appear to be similar in comparison to other countries (female, breech presentation, family history of DDH).

Long-term Results of Developmental Hip Dysplasia Under Therapy With Pavlik Harness

INTRODUCTION

The Pavlik harness is a commonly used treatment for developmental dysplasia of the hip (DDH) of types IIc or worse, based on the Graf classification. This study aimed to assess the long-term follow-up outcomes after treating DDH with the Pavlik harness.

METHODS

Between 1995 and 2006, ultrasound screening was conducted on 7372 newborns within the first days of life. Among them, 203 dysplastic hips in 152 patients, whose sonograms were Graf type IIc or worse, were treated with Pavlik harness. Treatment was discontinued if the measurement indicated Graf type Ia/b. More than 20 years later (mean: 20.46 y), patients were invited for clinical evaluation (Oxford Hips Score, Schulthess Hip Score, Harris Hip Score) and radiologic examination (center-edge angle according to Wiberg and the Severis classification, the rate of roofing of the femoral head via the Reimers migration percentage, and the Sharp angle).

RESULTS

Of the 152 patients, 60 (39.5%) participants with 80 (39.4%) affected hips (57.7% type IIc, 7.9% type D, and 15.6% type IIIa/b) were reexamined. The average follow-up duration was 20.5 years, with a maximum of 25.9 years. According to the Severin's classification, only 2 (3.77%) patients, each with one affected hip, showed slight residual dysplasia. The Reimer's migration percentage indicated an average of almost 90% canopy cover in the patient collective studied. No avascular necrosis was found, and the Sharp angle showed an average of almost 38 degrees. Only 4 participants with each one affected hip showed residual dysplasia according to the Sharp angle. The clinical results were quite satisfying, as none of the patients experienced hip pain that significantly limited their everyday activities or sports engagement, requiring medical attention before this study.Conclusions:Conservative therapy of DDH (Graf type IIc, D, III) with the Pavlik harness has demonstrated very good therapeutic success and a very low rate of residual dysplasia (2.81%). Both the radiologic and clinical outcomes were highly satisfactory.

LEVEL OF EVIDENCE

Level IV.

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.

A comprehensive nonoperative treatment protocol for developmental dysplasia of the hip in infants

Aims

Brace treatment is the cornerstone of managing developmental dysplasia of the hip (DDH), yet there is a lack of evidence-based treatment protocols, which results in wide variations in practice. To resolve this, we have developed a comprehensive nonoperative treatment protocol conforming to published consensus principles, with well-defined a priori criteria for inclusion and successful treatment.

Methods

This was a single-centre, prospective, longitudinal cohort study of a consecutive series of infants with ultrasound-confirmed DDH who underwent a comprehensive nonoperative brace management protocol in a unified multidisciplinary clinic between January 2012 and December 2016 with five-year follow-up radiographs. The radiological outcomes were acetabular index-lateral edge (AI-L), acetabular index-sourcil (AI-S), centre-edge angle (CEA), acetabular depth ratio (ADR), International Hip Dysplasia Institute (IHDI) grade, and evidence of avascular necrosis (AVN). At five years, each hip was classified as normal (< 1 SD), borderline dysplastic (1 to 2 SDs), or dysplastic (> 2 SDs) based on validated radiological norm-referenced values.

Results

Of 993 infants assessed clinically and sonographically, 21% (212 infants, 354 abnormal hips) had DDH and were included. Of these, 95% (202 infants, 335 hips) successfully completed bracing, and 5% (ten infants, 19 hips) failed bracing due to irreducible hip(s). The success rate of bracing for unilateral dislocations was 88% (45/51 infants) and for bilateral dislocations 83% (20/24 infants). The femoral nerve palsy rate was 1% (2/212 infants). At five-year follow-up (mean 63 months (SD 5.9; 49 to 83)) the prevalence of residual dysplasia after successful brace treatment was 1.6% (5/312 hips). All hips were IHDI grade I and none had AVN. Four children (4/186; 2%) subsequently underwent surgery for residual dysplasia.

Conclusion

Our comprehensive protocol for nonoperative treatment of infant DDH has shown high rates of success and extremely low rates of residual dysplasia at a mean age of five years.

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.

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.

Hip morphology on initial ultrasound predicts hip morphology at one year in developmental dysplasia of the hip

Purpose:

This study aimed to determine whether point-of-care ultrasound performed during the Pavlik method treatment of developmental dysplasia of the hip predicts acetabular morphology at 12 months of age.

Methods:

We reviewed the medical records, ultrasounds, and radiographs of patients treated successfully with the Pavlik method between 2017 and 2019. We performed sonographic measurements on point-of-care ultrasound at the initial presentation, the Pavlik discontinuation, and an additional sonographic follow-up. We measured the acetabular index on a plain anteroposterior radiograph of the pelvis obtained at a minimum of 12 months of age. Spearman’s rank correlation coefficient was used to analyze for correlation between sonographic measurements and the acetabular index.

Results:

A total of 72 patients were included in the final analysis. There were no residual or late dysplasia cases at the last radiographic follow-up (mean age = 14.8 ± 2.7 months). Sonographic parameters at the initial presentation significantly correlated with the acetabular index at the final radiographic follow-up (p < 0.001). Patients with worsening degrees of developmental dysplasia of the hip based on stability on sonographic testing (stable, unstable, or dislocated) had higher acetabular indices at the final radiographic follow-up (p < 0.05).

Conclusion:

Point-of-care ultrasound at initial presentation and the Pavlik discontinuation significantly correlate with acetabular morphology at 1–1.5 years of age. At initial presentation, hips that were unstable or dislocated on point-of-care ultrasound had significantly greater acetabular indices than stable hips at the final follow-up.

Level of evidence:

level IV case series.

Residual dysplasia of the hip after successful ultrasound-monitored treatment: how does an infant's hip evolve?

Despite that normal values for the hip joint are reached at the end of ultrasound-monitored-treatment, the development of the acetabulum can be compromised during the growth phase. The acetabular index (AI) measured on a pelvic radiograph has been proven to be a reliable parameter. The aim of this study is to gain a better understanding of the dynamics of once-treated, residually dysplastic hips. This should be achieved by radiographically following these hips up to a milestone-examination at the end of preschool age. A total of 120 hips of consecutive 60 infants were included in this examination, each presenting with a residual developmental dysplasia of the hips (DDH) after successful ultrasound-monitored harness treatment. Radiographic follow-up was assessed retrospectively around 18 months, 3 years and 6 years of age, and the AI was measured. The age-dependent Tönnis classification was applied. The hips were assigned normal, mildly or severely dysplastic. Dependent t -test for paired samples indicated a highly significant improvement of the AI-values, including from the first to the second and from the second to the third follow-up. The percentage distribution into the Tönnis classification changed remarkably: in the first follow-up, 36 of the 120 hips were evaluated 'severely dysplastic', in the third follow-up only 1. On the other hand, three hips underwent acetabuloplasty. Even after normal values have been achieved at the end of ultrasound-monitored treatment, there remains a risk of residual dysplasia of the hips. Particularly, when the first radiographic examination shows nonphysiological findings, further close-meshed follow-up is recommended. Level of evidence: retrospective study of therapeutic outcome, consecutive patients, level II.

Twelve-week standard of care protocol longer than median time to normalization among IIc hips treated with Pavlik harness

Best treatment protocols for infants with developmental dysplasia of the hip (DDH) are poorly defined. This study estimates the time to normalization among Graf IIc hips undergoing Pavlik harness treatment. Following institutional review board approval, patients referred for DDH evaluation at a pediatric institution between 2009 and 2018 (n = 1424 hips/712 patients) were identified. We isolated all Graf IIc hips that underwent Pavlik harness treatment (n = 132 hips/n = 106 patients). Demographic and outcome measures were collected. Normalization was defined as alpha angle greater than or equal to 60° and femoral head coverage greater than or equal to 50%. Kaplan-Meier and Cox proportional hazards regression analyses modeled time to normalization and identified factors associated with earlier normalization. Median time to normalization was 7.0 weeks. At 12 weeks standard treatment, 85.8% [95% confidence interval (CI): 80.2-91.9%] had normalized. Greater femoral head coverage [hazard ratio (HR) per 1% increase: 1.03; 95% CI: 1.01-1.05; P = 0.0068] and hip stability at treatment initiation (HR unstable vs. stable: 0.64; 95% CI: 0.44-0.93; P = 0.0192) were associated with longer time to normalization. Some patients may not need 12 weeks of Pavlik bracing, particularly those with stable presentation who normalize before week 12. Shorter treatment lengths offer benefit without sacrificing long-term outcomes. Findings reinforce growing evidence that femoral head coverage should be a more significant consideration during diagnosis and instability is a concerning finding on examination.

Does a Graf Type-I Hip Justify the Discontinuation of Pavlik Harness Treatment in Patients with Developmental Dislocation of the Hip?

Background: To analyze the clinical data of patients aged < 6 months with developmental dislocation of the hip (DDH) treated with Pavlik Harness (PH) in order to identify the best time to terminate PH treatment. Method: Fifty-four patients (47 females, 7 males; 63 hips) met the inclusion criteria and were included in the study; there were 33 (61.1%) left, 12 (22.2%) right and 9 (16.7%) bilateral DDH. The mean age at diagnosis was 11.8 ± 5.9 weeks (range, 1.4−25.5). All patients underwent fulltime PH treatment for about three months. At completion of PH treatment, patients were then divided into Group A, including patients with clinically stable hip joint and Graf type-I hip on ultrasound (US), and Group B, including patients with clinically stable hip joint and well-reduced hip on anterior-posterior (AP) radiographs without acetabular dysplasia. Six months after completion of PH treatment, the presence/absence of residual acetabular dysplasia (RAD) was evaluated on AP pelvis radiographs. The t-test and chi-square test were used to compare the differences in age, gender, side, Graf classification and RAD rate between the two groups of patients. Results: At completion of PH treatment, 45 hips were in Group A and 18 in Group B. There were no significant differences in age, gender, side, preoperative alpha angle and Graf classification between the two groups. Six months after discontinuation of PH, the AI in Group A (27.1° ± 6.8°) was significantly higher than that in Group B (21.9° ± 3.5°; p = 0.001); moreover 23 hips (51.1%) in Group A developed RAD compared to one hip in Group B (5.6%; p = 0.001). Among Group A patients, those with RAD were significantly older (13.7 ± 4.9 weeks) than those with normal hips (7.6 ± 3.8 weeks; p < 0.001); the incidence of RAD was significantly lower in patients with Graf type-II D hips (22.2%) than in patients with Graf type-III (70%) and type-IV hips (71.4%; p = 0.006). However, logistic regression analysis identified age as the only risk factor for RAD. All 24 hips with RAD (24/63, 38.1%) were treated with abduction braces. At final follow-up, AI in Group A (20.5° ± 3.3°) was not significantly different from that in Group B (21.9° ± 3.3°; p = 0.132). At the last follow-up visit, five hips (11.1%) in Group A still had RAD, compared to none in Group B (p = 0.31). Conclusions: In patients with DDH treated by PH, Graf type-I on US is not an absolute timing to terminate PH treatment. In addition, patients ≥ 13 weeks had a high risk of RAD despite PH treatment as 51.1% of infants developed RAD during follow up. Follow-up radiographs should be requested in all patients achieving Graf type-I hips at completion of PH treatment.

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.

Treatment of unstable hips with the Tübingen splint in early postnatal period: radiological mid-term results of 75 hips with mean follow-up of 5.5 years

PURPOSE

For treatment of unstable hips, the Tübingen splint is a treatment option. After the initial treatment, regular radiological follow-up examinations are recommended but there is a lack of long-term outcome studies. Therefore, the further development of unstable hips treated with the Tübingen splint were evaluated.

METHODS

From 2004 to 2015 116 patients with 161 unstable hips treated with the Tübingen splint were evaluated. Inclusion criteria were: 1) successfully treated unstable hip (type D, III and IV); 2) pelvic radiographs at the age of one to ≤ two, two to ≤ four and four to ≤ eight years. The acetabular index (ACI) of all and the centre-edge angle (CEA) of the third radiograph were measured and classified according to the Tönnis classification.

RESULTS

A total of 53 patients with 75 unstable hips (type D 34 (45.3%), III 33 (44.0%), IV 8 (10.7%)) were included. In comparison of the first, second and third radiograph, an increase of normal findings was seen in 31 (41.3%) to 53 (70.7%) and 60 (80.0%) hips, respectively. However, a decrease of slightly dysplastic hips from 31 (41.3%) to 19 (25.3%) and 14 (18.7%) respectively and severely dysplastic hips from 13 (17.3%) to three (4.0%) and one (1.3%) hip respectively was detected. In comparison of first to second radiograph, 32 hips improved and five hips deteriorated and of second to third radiograph 16 hips improved and six hips deteriorated. The Tönnis classification of ACI compared with CEA showed no significant differences (p = 0.442).

CONCLUSION

This study shows a good development of unstable hips treated with the Tübingen splint with mean follow-up 5.5 years. Nevertheless, unexpected deteriorations could be identified. The CEA is an alternative to the ACI.

LEVEL OF EVIDENCE

IV.