The success of closed reduction in the treatment of complex developmental dislocation of the hip

MRI assessment of femoral head docking following closed reduction of developmental dysplasia of the hip

AIMS

Eccentric reductions may become concentric through femoral head 'docking' (FHD) following closed reduction (CR) for developmental dysplasia of the hip (DDH). However, changes regarding position and morphology through FHD are not well understood. We aimed to assess these changes using serial MRI.

METHODS

We reviewed 103 patients with DDH successfully treated by CR and spica casting in a single institution between January 2016 and December 2020. MRI was routinely performed immediately after CR and at the end of each cast. Using MRI, we described the labrum-acetabular cartilage complex (LACC) morphology, and measured the femoral head to triradiate cartilage distance (FTD) on the midcoronal section. A total of 13 hips with initial complete reduction (i.e. FTD < 1 mm) and ten hips with incomplete MRI follow-up were excluded. A total of 86 patients (92 hips) with a FTD > 1 mm were included in the analysis.

RESULTS

At the end of the first cast period, 73 hips (79.3%) had a FTD < 1 mm. Multiple regression analysis showed that FTD (p = 0.011) and immobilization duration (p = 0.028) were associated with complete reduction. At the end of the second cast period, all 92 hips achieved complete reduction. The LACC on initial MRI was inverted in 69 hips (75.0%), partly inverted in 16 hips (17.4%), and everted in seven hips (7.6%). The LACC became everted-congruent in 45 hips (48.9%) and 92 hips (100%) at the end of the first and second cast period, respectively. However, a residual inverted labrum was present in 50/85 hips (58.8%) with an initial inverted or partly inverted LACC.

CONCLUSION

An eccentric reduction can become concentric after complete reduction and LACC remodelling following CR for DDH. Varying immobilization durations were required for achieving complete reduction. A residual inverted labrum was present in more than half of all hips after LACC remodelling.Cite this article: Bone Joint J 2023;105-B(2):140-147.

The limbus in developmental dysplasia of the hip: An obstacle to reduction and its images changed by the femoral head position

ABSTRACT

This study aimed to describe the shape of the limbus arthroscopically and via arthrogram and magnetic resonance imaging (MRI), and to determine whether it prevents concentric reduction of the femoral head in developmental dysplasia of the hip (DDH).Twelve patients (mean age, 10.2 months; range, 3-31 months) who underwent arthroscopic-assisted reduction for DDH were retrospectively reviewed. Limbus shapes were captured on arthrogram before reduction, after closed reduction, and after arthroscopic-assisted reduction and categorized according to the Miyake classification.On arthrogram, the superior limbus was blocked in 2 hips, inverted in 2, intermediate in 5, and everted in 3 after attempted closed reduction. After arthroscopic-assisted reduction, the limbus was everted in 7 hips and normal in 5. On arthroscopy, in all cases, the limbus appeared as a whitish, cartilage-like ring with a variably blunted edge before reduction, without inversion or eversion. On postoperative MRI, 10 of 12 superior limbi showed hypertrophy or globular compression by the femoral head with intermediate or mixed MRI signal intensities and blunted edges. The remaining 2 hips had hypertrophied superior limbi with sharp edges. On transverse plane MRI, the posterior limbus of all hips showed sharp margins with low MRI signal intensity. Residual subluxation was observed in 7 of the 12 hips with interposition of the anteroinferior limbus.The appearance of the limbus varied according to the femoral head position, and it was neither inverted nor everted. Interposed anteroinferior limbi with residual subluxation suggest impeded concentric reduction in DDH.

The role of the labrum in early treatment of unstable developmental dysplasia of the hip

The objective of the paper is to analyse the role of the labrum with particular attention to its morphological changes in unstable dysplastic hips during treatment.

Between January 2013 and December 2015, data were collected on 86 unstable, dysplastic hips, which were divided into type D (n = 13), type III (n = 49) and type IV (n = 24). The labrum was evaluated with ultrasound examination (US) for echogenicity and dimensions with inter-/intra-observer tests comparing the US images at diagnosis and at the end of treatment. Statistical analysis was performed.

At the end of treatment of unstable, dysplastic hips, the labrum was more echogenic with a frequency of 97% and was larger with a frequency of 96%.

The labrum has an active stabilizing role in unstable dysplastic hips and it undergoes a statistically significant increase of echogenicity and dimensions after treatment.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180053

Ultrasonographic changes of labrum morphology in patients with developmental dysplasia of the hip: a preliminary report on 74 dysplastic and unstable hips

The aim of the study was to verify the labrum's morphological changes in unstable and dysplastic hips during treatment. Between January 2013 and April 2015, 74 dysplastic hips were divided into type D (n=12), type III (n=40), and type IV (n=22). The labrum was evaluated on ultrasonography (US) for echogenicity and dimensions with interobserver/intraobserver tests: test 1 (US at diagnosis and control group), test 2 (US at diagnosis and 6 weeks post-treatment), and test 3 (US at diagnosis and at end of treatment). Statistical analysis was performed. The labrum was less echogenic in test 1 and more echogenic in test 3, and the labrum was smaller in test 1 and larger in test 3. The labrum undergoes statistically significant increase of echogenicity and dimensions after treatment, suggesting a stabilizing role. Level of Evidence: Level II, Oxford Center for Evidence-based Medicine.

Association between open or closed reduction and avascular necrosis in developmental dysplasia of the hip: A PRISMA-compliant meta-analysis of observational studies

BACKGROUND

The risk of avascular necrosis of the femoral head (AVN) after treatment of developmental dysplasia of the hip is associated with the method of reduction. Some authors have suggested that open reduction is a risk factor for AVN; however, this is controversial. To our knowledge, a quantitative comparison of the incidence of AVN between closed and open reduction has not been conducted.

METHODS

Published studies were identified by searching PubMed, EMBASE, and the Cochrane Library up to May, 2015, focusing on the incidence of AVN after closed or open reduction for developmental dysplasia of the hip in children aged <3 years. Patients were age-matched who were treated by either closed or open reduction, but without pelvic or femoral osteotomy. Two authors independently assessed eligibility and abstracted data. Discrepancies were discussed and resolved by consensus. We pooled the odds ratios (ORs) and 95% confidence intervals (95%CIs) from individual studies using a random-effects model and evaluated heterogeneity and publication bias.

RESULTS

Nine retrospective studies were included in this analysis. The pooled OR for comparing open reduction with closed reduction for all grades of AVN was 2.26 (95%CI = 1.21-4.22), with moderate heterogeneity (I = 44.7%, P = 0.107). The pooled OR for grades II to IV AVN was 2.46 (95%CI = 0.93-6.51), with high heterogeneity (I = 69.6%, P = 0.003). A significant association was also found for the further surgery between open and closed reduction, with a pooled OR of 0.30 (95%CI = 0.15-0.60) and moderate heterogeneity (I = 46.4%, P = 0.133). No evidence of publication bias or significant heterogeneity between subgroups was detected by meta-regression analyses.

CONCLUSION

Findings from this meta-analysis suggest that open reduction is a risk factor for the development of AVN compared with closed treatment. Future studies are warranted to investigate how open reduction combined with pelvis and/or femoral osteotomy affects the incidence of AVN.

The presence of an ossific nucleus does not protect against osteonecrosis after treatment of developmental dysplasia of the hip

BACKGROUND

Osteonecrosis (ON) is a major complication after treatment of developmental dysplasia of the hip (DDH). Several studies have explored the absence of the femoral head ossific nucleus at the time of hip reduction as a risk factor for the development of ON, but findings have been inconsistent.

QUESTIONS/PURPOSES

We therefore determined the incidence of ON in children who underwent reduction of a dislocated hip in the presence or absence of the ossific nucleus.

PATIENTS AND METHODS

We retrospectively reviewed the radiographs of 105 hips in 89 patients treated for DDH at the age of 18 months or younger. Radiographs were graded for the presence of the ossific nucleus at the time of hip reduction and for the presence of ON, as graded by the Bucholz and Ogden classification, for patients at a mean age of 10 years. We used log-binomial regression to estimate if the presence of the ossific nucleus was associated with a lower incidence of ON.

RESULTS

We identified ON in 37 of the 105 hips (35%). The incidence of ON at 10 years was 40% in the absence of the ossific nucleus and 32% in the presence of the ossific nucleus (adjusted relative risk, 0.86; 95% confidence interval, 0.36-1.81). When only radiographic changes of Grade II and greater were considered ON, the risk was still not increased (relative risk, 1.26; 95% confidence interval, 0.62-2.56).

CONCLUSION

Patients with an ossific nucleus at the time of hip reduction showed a slight tendency toward better outcomes. The ossific nucleus did not protect for ON.

LEVEL OF EVIDENCE

Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Ossification of the femoral head at closed reduction for developmental dysplasia of the hip and its influence on the long-term outcome

The management of developmental dysplasia of the hip, particularly the timing of closed reduction with regard to the presence of the femoral head ossific nucleus, is controversial. The clinical and radiological outcome was assessed in a strictly defined group of 48 hips in 42 patients with an average of 11.1 years follow-up. One hundred percent of patients had an excellent or good result at final follow-up; 8.3% showed evidence of avascular necrosis and six hips underwent further surgery after closed reduction. There was no relationship between the presence or absence of an ossific nucleus at the time of closed reduction and the final outcome. In this well-defined group, closed reduction is safe and provides excellent results in the long term.

The surgical treatment of established congenital dislocation of the hip: results of surgery after planned delayed intervention following the appearance of the capital femoral ossific nucleus

It has been proposed that the presence of the capital femoral ossific nucleus confers protection against ischemic injury or avascular necrosis (AVN) at the time of reduction of a congenitally dislocated hip. The current literature is contradictory. A prospective study was undertaken of the clinical and radiologic outcomes following closed or open reduction. Fifty hips were included in the study. These cases had presented late or had failed conservative treatment. In 28 hips treatment was intentionally delayed until the appearance of the ossific nucleus (but not beyond 13 months) and in 22 the ossific nucleus was present at clinical presentation. Six hips reached the age of 13 months without an ossific nucleus appearing and progressed to treatment. The significant AVN rate (more than grade 1) was 7% for closed reduction and 14% for open. However, the amended rate if hips were excluded that had failed Pavlik harness treatment was 0.0% and 9%, respectively (4% overall). Further surgical procedures were necessary in 57% of hips undergoing closed reduction and 41% after open, which compares favorably with other series. The authors conclude that the presence of the ossific nucleus is an important factor in the prevention of AVN, particularly after late closed reduction. Intentional delay in the timing of surgery does not condemn a hip to open surgery, but there is a comparable rate of secondary procedures becoming necessary, particularly after closed reduction. A simultaneous pelvic procedure may be appropriate after late closed reduction. The delayed strategy to await the appearance of the ossific nucleus for previously untreated dislocation allows a simple treatment algorithm to be employed that produces good clinical and radiologic outcomes.

The role of arthrography-guided closed reduction in minimizing the incidence of avascular necrosis in developmental dysplasia of the hip

Avascular necrosis of the femoral head is the most serious complication after closed reduction in developmental dysplasia of the hip. Although arthrography has a well-established role in the treatment of developmental dysplasia of the hip, its use is not universal. A prospective study was conducted to compare the incidence of avascular necrosis after closed reduction in developmental dysplasia of the hip performed with and without arthrography in 85 patients, with a minimum of 5 years follow up. Arthrographic criteria were evaluated including lateralization of the femoral head and the type of limbus encountered. Hips treated by closed reduction based on arthrographic evaluation had significantly less incidence of avascular necrosis when compared with those treated by closed reduction without arthrographic guidance. Closed reduction with lateralization of more than 4 mm, and those hips with an inverted limbus were associated with an increased risk of avascular necrosis.

Magnetic resonance arthrography in children with developmental hip dysplasia

Conventional and gadolinium enhanced magnetic resonance arthrograms were done on 14 hips in 10 children ages 7 to 24 months. The contralateral normal hips in those with unilateral disease were studied with unenhanced magnetic resonance imaging for comparison. By conventional arthrography, there were no well visualized structures. Visualized structures seen as filling defects were the labrum, ligamentum teres, and transverse acetabular ligament. By magnetic resonance arthrography, well visualized structures were the labrum, ligamentum teres, transverse acetabular ligament, and pulvinar. By unenhanced magnetic resonance imaging, well visualized structures were the labrum, ligamentum teres, and transverse acetabular ligament. The difference in visualization by magnetic resonance arthrography versus conventional arthrography was statistically significant with respect to all five structures: labrum, ligamentum teres, transverse acetabular ligament, pulvinar, and psoas tendon. The difference in visualization by magnetic resonance arthrography versus unenhanced magnetic resonance imaging was statistically significant with respect to the labrum and pulvinar. Magnetic resonance arthrography is indicated for assessing complete concentric reduction when it does not appear to be achieved by conventional arthrography, for confirming closed reduction immediately after manipulation, and potentially for preoperative planning for an open reduction.

Utility of MRI in detecting obstacles to reduction in developmental dysplasia of the hip: comparison with two-directional arthrography and correlation with intraoperative findings

We studied the utility of magnetic resonance imaging (MRI) in detecting obstacles to reduction in developmental dysplasia of the hip (DDH) by comparing MRI findings with two-directional arthrograms and intraoperative findings. In 36 patients there were 38 DDHs; 23 complete dislocations and 15 residual subluxations. Coronal and transverse sections of T1-weighted images were used. Interpositions in the acetabulum and the anterior, superior, and posterior portions of the limbus, which were intracapsular obstacles to reduction, were evaluated. MRI and arthrography were useful for assessing the shape of the anterior portion of the limbus. In complete dislocations, MRI findings proved more valuable to detect deformities of the posterior portion of the limbus. Four of ten limbus excisions showed intermediate intensity signals on MRI. The histology was characterized by reparative granulation tissue with new capillary formation and organized thrombi. MRI proved useful for detecting obstacles to reduction, as well as for assessing morphological and histological abnormalities.

The prognostic importance of the ossific nucleus in the treatment of congenital dysplasia of the hip

Ischemic necrosis of the femoral head occurring after the treatment of congenital dysplasia of the hip can negatively affect the long-term prognosis of the involved hip. Some investigators have suggested that the presence of the ossific nucleus of the femoral head at the time of closed or open reduction is associated with a lower rate of ischemic necrosis. This finding, if verified, could lead to a delay in the treatment of a dislocated hip until ossification of the femoral head has begun, which may be well after the age when the patient has started to walk. We conducted a computerized search of the medical records at our two tertiary-care children's hospitals to identify all patients with congenital dysplasia of the hip who had had a closed or open reduction between January 1, 1979, and December 31, 1993. One hundred and twenty-four patients (153 hips) who satisfied the criteria for inclusion were identified. The ossific nucleus was present in ninety hips and absent in sixty-three. Closed reduction was used in 112 hips and open reduction, in forty-one. Ischemic necrosis was identified in five hips (3 percent): four (6 percent) of the sixty-three hips that did not have an ossific nucleus and one (1 percent) of the ninety hips that had an ossific nucleus at the time of the reduction. With the numbers available for study, we could not detect a difference between these two groups. The age at reduction (p > 0.99), the method of reduction (p = 0.611), previous treatment with a Pavlik harness (p = 0.592), the use of preliminary traction (p = 0.602), concomitant procedures (p > 0.99), and a failure of the primary closed reduction (p = 0.579) were not associated with the development of ischemic necrosis after reduction. In our analysis of patients who were managed over a fifteen-year period, the data did not support the hypothesis that the presence of an ossific nucleus at the time of reduction of a congenitally dislocated hip is associated with a lower prevalence of ischemic necrosis of the femoral head. Sound operative principles dictate that operative reduction of a congenitally displaced hip should be performed when the child can be safely placed under anesthesia and without regard to the presence or absence of the ossific nucleus.