The epidemiology of developmental dysplasia of the hip in Japan: Findings from a nationwide multi-center survey

Infections with Klebsiella pneumoniae in Children Undergoing Anticancer Therapy or Hematopoietic Cell Transplantation: A Multicenter Nationwide Study

Background:Klebsiella pneumoniae is a nosocomial pathogen that causes severe infections in immunocompromised patients. The aim of the study was to conduct a microbiological and clinical analysis of K. pneumoniae infections in children with malignancies or undergoing hematopoietic cell transplantation in Poland. Methods: We conducted a retrospective, multicenter study including children and adolescents under 19 years old treated between 2012 and 2021. We analyzed patients' characteristics, microbiological data, and the outcomes of antibiotic therapy. Results: A total of 9121 newly diagnosed children were treated for malignancy and 1697 pediatric patients underwent hematopoietic cell transplantation. K. pneumoniae infections were diagnosed in 527 patients. Their overall incidence was 4.86% in pediatric hematology and oncology patients and 4.95% in patients who underwent hematopoietic cell transplantation. The incidence of infection was higher in patients with acute leukemia than with solid tumors (7.8% vs. 4.1%; OR = 2.0; 95% CI = 1.6-2.4; p < 0.0001). The most frequent source of infection was in the urinary tract at 55.2%. More than 57% of K. pneumoniae strains were extended-spectrum β-lactamase-positive and almost 34% were multidrug-resistant. Infections with K. pneumoniae contributed to death in 3.22% of patients. Conclusions: K. pneumoniae is one of the most critical pathogens in children suffering from malignancies or undergoing hematopoietic cell transplantation. The incidence of multidrug-resistant K. pneumoniae strains is increasing and contributing to poor clinical outcome.

Validation of parameters recommended for secondary screening for developmental dysplasia of the hip in Japan

BACKGROUND

Based on the Japanese Pediatric Orthopaedic Association's guidelines, secondary screening and imaging including ultrasonography and radiography, are recommended in infants with limited hip abduction (<70°) or in those with multiple risk factors including the following: asymmetrical skin creases, a family history of developmental dysplasia of the hip, female sex, and pelvic position at delivery. However, there is still little information regarding the usefulness of this guideline. The objective of this study was to investigate the association between the risk factors and developmental dysplasia of the hip diagnosed using ultrasound and radiography.

METHODS

A total of 356 infants (67 boys and 289 girls) underwent secondary ultrasonographic and radiological screening for developmental dysplasia of the hip in our hospital. Risk factors were documented from their medical records. The recommended item score, which we defined as an integrated value of the recommended item, was calculated for each patient. The limitation of hip abduction alone was a criterion for secondary screening; therefore, we defined the scores as follows: the limitation of hip abduction scored 2 points and other recommended scores were assigned 1 point. If the recommended item score was 2 points or more, we classified the infants as high-risk.

RESULTS

A total of 280 of 356 infants were included in the high-risk group, which showed a higher ratio of cases with abnormal imaging findings than the low-risk group. According to the multivariate logistic regression analyses among the recommended items, being female, skin asymmetry, and limb limitation were identified as independent risk factors for imaging abnormality and the need for Pavlik harness treatment.

CONCLUSIONS

The recommended items for secondary screening based on the Japanese Pediatric Orthopaedic Association's guidelines could be useful for screening infants in need of treatment.

Quality of life in adult patients with developmental dysplasia of the hip who were treated for hip dislocation during childhood

Developmental dysplasia of the hip (DDH) can lead to premature loss of hip function if not properly treated; however, few studies have focused on the long-term outcomes of DDH. We conducted a survey of health-related quality of life in adult patients with DDH who were treated for hip dislocation during childhood. We sent a questionnaire to 287 adult patients with DDH who were treated for hip dislocation during childhood in our institutions. We examined patient demographics, disease-specific medical history, and health-related quality of life using the short form-36. Physical component summary (PCS), mental component summary (MCS) and role/social component summary (RCS) were compared between the patients and Japanese standard values. Sixty-eight patients were evaluated after exclusion. The overall mean PCS, MCS and RCS scores of the patients were comparable to the standard values. The PCS was maintained until the age of 50, but it was significantly decreased in 10 patients over 50 years old. In addition, PCS was significantly lower in patients who underwent open reduction than in those who were conservatively reduced. The MCS and RCS of the patients did not differ from the standard values in each age and treatment group. Additionally, the PCS, MCS and RCS did not differ according to bilaterality, age at diagnosis, or requirement for additional surgeries. Physical quality of life was maintained until the age of 50 but rapidly declined thereafter in patients with DDH, especially in those who required open reduction during childhood.

Family History of Developmental Dysplasia of the Hip is a Risk Factor for the Progression of Hip Osteoarthritis

BACKGROUND

Developmental dysplasia of the hip (DDH) is considered to have genetic predisposition and presents many intrafamilial occurrences. However, there is no report that evaluates the effect of DDH family history on the progression after the onset of hip osteoarthritis (OA).

METHODS

Medical interviews about detailed clinical information including family history were conducted on 298 consecutive patients who had undergone surgery for OA due to DDH. Clinical or radiographic items that are associated with the severity of DDH (total hip arthroplasty [THA], involvement of bilateral DDH, onset age of hip pain, and three radiological indices of DDH: center-edge angle, sharp angle, and acetabular roof obliquity) were collected and evaluated in multivariate analyses for their associations with DDH family history in a qualitative or quantitative manner. Survival time analyses for THA as the endpoint was also performed to evaluate the effects of DDH family history on the progression of OA.

RESULTS

The DDH family history showed significant associations with bilateral involvement of DDH (odds ratio = 2.09 [95% confidence interval {CI} 1.05 to 4.16]; P = .037), early onset of hip pain (P = .0065), and radiological severity of DDH (P = .016). The DDH family history showed a significant association with undergoing THA (odds ratio = 2.25 [95% CI 1.09 to 4.66]; P = .029), further supported by the Cox regression analyses (hazards ratio = 1.56 [95% CI 1.15 to 2.11]; P = .0044).

CONCLUSION

A DDH family history is a risk factor for the progression of hip OA. Stronger genetic predisposition to DDH leads to faster onset and progression of hip OA.

Developing an Educational Program for Ultrasound Hip Screening during Newborn and Infant Home Visits: A Protocol Paper

Ultrasound hip screening is suitable for the early identification of developmental dysplasia of the hip (DDH). Newborn and infant home visits are good opportunities for hip screening in the community, but studies focusing on nurse-led screenings are lacking. Based on a pre-post design, this study aims to develop and evaluate an ultrasound training program to improve nurses' assessment skills in detecting DDH cases during newborn and infant home visits. Said educational program will include e-learning, hands-on seminars, and clinical training. The primary outcome will be the success rate of imaging standard planes (standardized images for hip assessment) in clinical training. The secondary outcomes will include knowledge test results, objective structured clinical examination scores, time required for imaging, and inter-rater reliability between nurses and physicians. The educational program will address the issue of missed and late detection of DDH cases in resource-limited communities. This study will demonstrate the feasibility of procedures and the effectiveness of the educational program in 2024. The protocol was registered in the University Hospital Medical Information Network Clinical Trial Registry before starting the study (no. UMIN000051929, 16 August 2023).

Bilateral Involvement in Developmental Dislocation of the Hip: Analysis of 561 Patients Operated on Using the Limited Posteromedial Approach

Our objective was to scrutinize the risk factors related to bilateral involvement in the developmental dysplasia of the hip (DDH) and to inspect the impact of bilaterality on the enduring results of the DDH. All patients, aged between 6 and 18 months, who underwent surgery using the limited posteromedial approach (734 hips from 561 patients), were included in this study. The number of births, birth type, history of consanguineous marriage, family history, and swaddling were analyzed. Physical examination and complaints of the patients were evaluated, and direct radiographs were examined in terms of the redislocation, avascular necrosis, and residual acetabular dysplasia. Among the 561 patients, bilateral DDH was observed in 173 patients (30.8%). The use of swaddling was found to be statistically significant between groups (p = 0.012). The use of swaddling for more than one month was associated with a higher odds ratio for bilaterality (p = 0.001, OR = 1.56, 95% CI: 1.2-2.0). Furthermore, bilaterality was associated with a higher risk for redislocation in DDH (p = 0.001, OR = 4.25, 95% CI: 1.6-11.2). The study concludes that swaddling for over a month is strongly linked with the bilateral involvement in DDH. It is important to note that bilaterality plays a crucial role in the development of redislocation after open reduction in DDH.

Community-Based Hip Screening for Up to Four-Month-Old Infants and Health Guidance for Their Caregivers in Japan: A Nation-Wide Survey

Early detection of developmental dysplasia of the hip (DDH) in children is crucial. Due to COVID-19, maternal and child health services have been suspended temporarily, increasing the risk of late detection of DDH. This study aimed to reveal Japan's current situation regarding community hip screening for newborns and infants and to provide health guidance for caregivers regarding DDH. A web-based, nationwide cross-sectional survey was conducted between February and March 2023 (n = 1737). One public health nurse overseeing maternal and child health per municipality responded to the 2022 municipality hip screening system. Among the 436 municipalities that responded (response rate: 25.1%), 97.5% implemented hip screening within 4 months, and approximately 60% performed it during newborn home visits, while only 2.3% conducted hip ultrasound screening. Perfect checking of the risk factors for DDH during newborn home visits and training opportunities for home visitors must be improved. Educational programs regarding DDH for home visitors and caregivers are needed to prevent the late diagnosis of DDH. Furthermore, collaboration between pediatric orthopedic surgeons and nurses is crucial for developing effective community-based hip-screening systems by bridging the evidence and practice gap in the early detection of DDH.

Appropriate Surgical Timing of Salter Innominate Osteotomy for Residual Acetabular Dysplasia in Children

BACKGROUND

Salter innominate osteotomy (SIO) provides favorable results for treating residual acetabular dysplasia in young children. In this study, we examined the midterm results of SIO according to the age at surgery to determine the optimal timing of this procedure.

METHODS

We retrospectively examined 50 hips of 42 patients (8 boys and 34 girls) with acetabular dysplasia who underwent SIO and were followed up until skeletal maturity. The center-edge angle (CEA) was measured based on the anteroposterior radiographs of the hip obtained before surgery, 5 weeks after surgery, and at the latest follow-up. Severin classification was evaluated at the latest follow-up. Patients were categorized into 3 groups according to age at surgery: younger than 7 years of age (group A), 7 to 8 years of age (group B), and 9 years of age or older (group C).

RESULTS

The mean preoperative CEA level of 0.9 degrees improved to 17.1 degrees postoperatively, which was increased to 28.1 degrees at the latest examination. Overall, 45 hips (90%) were classified as Severin I or II, with 96% in group A, 94% in group B, and 57% in group C. In group C, postoperative acetabular coverage was similar to that in the other groups (16.6 degrees in group A, 14.8 degrees in group B, and 18.1 degrees in group C), although the final outcome was unsatisfactory. The average improvement in CEA from postoperative to skeletal maturity was significantly smaller in group C than in the other groups (12.7 degrees in group A, 11.3 degrees in group B, and 3.0 degrees in group C).

CONCLUSIONS

SIO showed favorable outcomes with satisfactory acetabular coverage at skeletal maturity. However, satisfactory acetabular coverage could not be obtained in some older patients because of limited postoperative remodeling capacity and smaller secondary improvement of CEA. We recommend that SIO should be performed in patients aged 8 years or younger.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Epidemiology of developmental dysplasia of the hip: analysis of Japanese national database

BackgroundDevelopmental dysplasia of the hip (DDH) is a cluster of hip development disorders that affects infants. The incidence of DDH-related dislocation (DDH-dislocation) is reportedly 0.1-0.3%; however, the nationwide incidence of DDH-dislocation in Japan has not been previously reported. The primary aim of this study was to report the nationwide incidence of DDH-dislocation in Japan using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), and to examine its regional variation across Japan.MethodsThis was a retrospective birth cohort study using the NDB. Data on patients born between 2011 and 2013 and assigned DDH-dislocation-related disease codes during 2011-2018 were extracted. Among these, patients who underwent treatment for DDH-dislocation between 2011 and 2018 were defined as patients with DDH-dislocation.ResultsAcross the 2011, 2012, and 2013 birth cohorts, 2367 patients were diagnosed with DDH-dislocation, yielding the nationwide incidence of 0.076%. Region-specific incidence rates were almost similar across Japan. Secondary analyses revealed that 273 (11.5%) patients were diagnosed at the age of ≥1 year. The effect of birth during the cold months on the incidence of DDH-dislocation was significant (relative risk [RR]=1.89, 95% confidence interval [CI]: 1.75-2.06). The risk of DDH-dislocation among girls was approximately seven times higher than that among boys.ConclusionsThis is the first study to report the nationwide incidence of DDH-dislocation in Japan, which was estimated at 0.076%. The regional variation was trivial and unlikely to be clinically significant. Thus, the incidence rates were approximately equal across all regions in Japan.

A longitudinal study for the prediction of the mature acetabular morphology using childhood magnetic resonance imaging

BACKGROUND

Although acetabular dysplasia is a common etiology of osteoarthritis of the hip regardless of the history of developmental dysplasia of the hip (DDH), whether or not corrective surgeries are beneficial for the childhood asymptomatic acetabular dysplasia remains controversial due to a lack of evidence. We conducted a longitudinal study to compare the cartilaginous morphology on childhood magnetic resonance imaging (MRI) and the mature hip morphology of the same patient and to assess the predictive indicators for future acetabular dysplasia.

METHODS

A total of 92 unaffected hips (47 unilateral DDH and 45 unilateral Legg-Calvé-Perthes disease) were reviewed for X-ray and MRI findings on childhood (mean age: 6.0 years) and X-ray findings from a skeletally mature age with a mean follow-up period of 15.1 years. The following parameters were measured and compared: the immature-acetabular index (AI) and center edge angle (CE) on immature X-ray; the cartilage- and bone- AI, CE, Sharp and acetabular head index (AHI) on childhood MRI; and the mature-acetabular roof obliquity (ARO), CE, Sharp and AHI on skeletally mature X-ray. The prognostic factors on childhood MRI for acetabular dysplasia, defined by a CE of <20° on skeletally mature X-ray were also assessed.

RESULTS

Positive correlations were shown between the cartilage-AI and mature-ARO (7.6°/6.3°; r = 0.44), the cartilage-CE and mature-CE (27.8°/28.0°; r = 0.62), the cartilage-Sharp and mature-Sharp (44.4°/41.8°; r = 0.52) and the cartilage-AHI and mature-AHI (78.7%/80.3%; r = 0.46). A multivariate analysis indicated cartilage-CE to be an independent predictor for acetabular dysplasia with a cut-off value of 22°. Children with a cartilage-CE <22° developed more frequently acetabular dysplasia compared to the others (52.4% vs. 1.4%).

CONCLUSIONS

Childhood MRI findings are useful for the prediction of acetabular dysplasia without a DDH history. Children with a cartilage-CE ≥23° are likely to achieve a non-dysplastic hip without the need for surgical intervention.

Pelvic osteotomies for acetabular dysplasia: Are there outcomes, survivorship and complication differences between different osteotomy techniques?

The purpose of this study was to evaluate the safety and efficacy of Periacetabular osteotomy (PAO), rotational acetabular osteotomy (RAO), and eccentric rotational acetabular osteotomy (ERAO) for treating hip dysplasia by comparing complication rates, survivorship, and functional outcomes after treatment. A systematic review in the MEDLINE and CINAHL databases was performed, and studies reporting outcomes after pelvic osteotomy for hip dysplasia with a minimum of 1-year follow-up or reported postoperative complications was included. Patient demographics, radiographic measurements, patient reported outcomes including the modified Harris hip score (mHHS), complications using the modified Clavien-Dindo classification, and reoperations were extracted from each study. A meta-analysis of outcome scores, complications, change in acetabular coverage, and revision rates for the 3 pelvic osteotomies was performed. A total of 47 articles detailing outcomes of 6,107 patients undergoing pelvic osteotomies were included in the final analysis. When stratified by procedure, RAO had a statistically greater change in LCEA when compared to PAO (33.9° vs 18.0°; P <0.001). The average pooled mHHS improvement was 15.6 (95% CI: 8.3–22.8, I²= 99.4%). Although ERAO had higher mean score improvements when compared to RAO and PAO, the difference was not statistically significant (P >0.05). Lastly, patients undergoing PAO had a statistically greater complication rate than those undergoing ERAO and RAO (P <0.001 for both), while revision rate was not statistically different between the 3 techniques. In summary, there are many more publications on PAO surgery with a wide range of reported complications. Complications after ERAO and RAO surgery are lower than PAO surgery in the literature, but it is unclear whether this represents an actual difference or a reporting bias. Lastly, there are no significant differences between revisions, or postoperative reported outcomes between the 3 techniques.

Total Hip Arthroplasty for Developmental Dysplasia of Hip vs Osteoarthritis: A Propensity Matched Pair Analysis

Background

The purpose of this study was to use the American College of Surgeons National Surgical Quality Improvement Program to compare the perioperative and postoperative outcomes after total hip arthroplasty (THA) for DDH and primary OA via a propensity-matched pair analysis and the valuation of THA between both groups.

Material and Methods

All patients who underwent THA between 2008 and 2016 were identified from National Surgical Quality Improvement Program database via the current procedural terminology (CPT) code. Patients were further identified and stratified based on International Statistical Classification of Diseases and Related Health Problems-9/International Statistical Classification of Diseases and Related Health Problems-10 diagnosis codes for primary OA (n = 115,166) and DDH (n = 603), which included codes for congenital hip dislocation, hip dysplasia, or juvenile osteochondrosis. Demographic variables were used to create 557 propensity-matched pairs.

Results

The DDH group was associated with a significantly longer operative time (120.3 vs 95.9 min), higher postoperative transfusion rate (12% vs 6.6%), and longer hospital length of stay (2.8 vs 2.5 days) compared with the primary OA group (P < .001, P < .001, and P = .002, respectively). There were no statistically significant differences found between the two groups with respect to inpatient complications, discharge disposition (P = .123), readmissions (P = .615), or reoperations (P = .404).

Conclusions

Health policy makers should be cognizant of the higher complexity of THA for DDH when determining whether DDH and primary OA should be in the same bundle. Owing to the limitations of our data set, all the observed associations are likely an underestimate of the true risk posed to patients with severe DDH, as these patients were unable to be stratified in the present analysis.

Evaluation of errors in measurements of infantile hip radiograph using digitally reconstructed radiograph from three-dimensional MRI

Purpose

Plain hip radiograph is commonly used for the diagnosis of infantile acetabular dysplasia. Many infants are unable to maintain adequate position during radiography. Besides, the infantile hip is much smaller and has a higher cartilage component in the acetabulum and proximal femur compared with the adult hip. In this study, we developed a digitally reconstructed radiograph synthesized from magnetic resonance imaging (MRI) and investigated errors of hip radiographic measurements in different pelvic positions.

Patients and methods

MRI of both hips was performed in 10 patients (mean age 3.9 years). Three-dimensional (3D) bone models were created from MRI data. We tilted 3D pelvic bone models between 10° anteversion and retroversion and through 10° rotation on the affected and contralateral sides using 3D axes. Following this, we created digitally reconstructed radiographs in each pelvic position and calculated the acetabular index (AI), center-edge angle (CEA), migration percentage (MP), and teardrop distance (TDD).

Results

AI tended to increase with pelvic retroversion and did not change with pelvic rotation. CEA tended to decrease with pelvic retroversion and rotation on the contralateral side. MP increased with pelvic retroversion and rotation on the contralateral side. TDD did not change significantly with pelvic tilt and rotation.

Conclusions

Radiographic measurements of hip in infants were highly influenced by pelvic movement. AI was influenced by pelvic tilt; CEA and MP were influenced by both pelvic tilt and rotation. We need to keep in mind that infantile hip radiographs could have about ±5° errors in AI and CEA.

Intraoperative hemorrhage in revision total hip arthroplasty: a retrospective single-center study

PURPOSE

The amount of intraoperative hemorrhages and factors associated with hemorrhages and transfusions during revision total hip arthroplasty (reTHA) have not been identified for Japanese patients. We aimed to clarify the amount of intraoperative hemorrhages, and to elucidate the factors associated with hemorrhages and transfusions during reTHA in Japanese patients.

METHODS

We retrospectively reviewed patients who underwent reTHA (n = 48) and primary total hip arthroplasty (pTHA) (n = 615) in a single hospital and extracted data regarding hemorrhage, transfusion, patient comorbidities, and surgical anesthesia. We defined massive blood loss (MBL) as a hemorrhage comprising more than half of the circulating blood volume within 3 h. The odds ratio (OR) and 95% confidence interval (CI) were estimated using a multivariate logistic regression analysis.

RESULTS

There was a significant difference in hemorrhages between reTHA and pTHA patients (1790 g versus 625 g; p < 0.001). Among patients with reTHA, MBL was significantly associated with younger age (OR 0.91; 95% CI 0.84-1.00; p = 0.04) and lower body mass index (BMI) (OR 0.69; 95% CI 0.53-0.91; p = 0.01). Although not significant, the incidence of MBL tended to be higher for patients with hyperlipidemia (OR 4.88; 95% CI 0.99-24.1; p = 0.051). Furthermore, the need for allogeneic transfusion was significantly associated with the number of prepared autologous blood packs (OR 0.15; 95% CI 0.07-0.55; p = 0.002).

CONCLUSION

Although this study was limited by its small population and a possibility of underestimating the hemorrhage, hemorrhages in reTHA patients was two times greater than that in pTHA patients. Younger age and lower BMI increased the risk of MBL in reTHA. Preparing autologous blood decreased the risk of intraoperative allogeneic transfusion.

Instability of the Hip Joint After Posterior Acetabular Wall Fracture: Independent Risk Factors Remain Elusive

BACKGROUND

Exact determinants of hip instability have not been established for fractures of the posterior wall of the acetabulum involving ≤50% of the wall. Therefore, examination of the hip under anesthesia (EUA) is routinely performed. Recently, the superior exit point of the fracture has been reported to be an important identifiable risk factor. Pre-existing adult hip dysplasia (developmental dysplasia of the hip [DDH]) is thought to have a similar role. The purpose of this study was to determine if any known radiographic measurements and signs associated with DDH, or any fracture characteristics, are independent risk factors for hip instability after fracture of the posterior wall of the acetabulum.

METHODS

All patients with a posterior acetabular wall fracture (OTA 62.A1) treated at our institution between 2004 and 2015 were considered for the study. Inclusion criteria were an age of ≥18 years, an isolated posterior acetabular wall fracture involving ≤50% of the acetabular wall, adequate imaging, and documented EUA results. Evaluated variables included fracture fragment size, superior exit point of the fracture, center-edge angle, acetabular index, Tönnis angle, lateralized head sign, crossover sign, posterior wall sign, ischial spine sign, and hip version. Data were examined using univariate testing, followed by a multivariate logistic regression analysis.

RESULTS

Sixty-eight patients met all of the inclusion criteria. Univariate analyses identified the posterior wall sign (p = 0.033), ischial spine sign (p = 0.030), and proximity of the superior exit point of the fracture to the acetabular dome (p = 0.044) as having a significant association with hip instability. However, multivariate logistic regression modeling revealed that none of these factors were significant independent risk factors.

CONCLUSIONS

Consistent with previous studies, univariate analyses identified certain radiographic findings as significant risk factors for hip instability in the setting of a fracture of the posterior wall of the acetabulum. However, subsequent multivariate logistic regression modeling showed that no studied variable was an independent risk factor. Our results indicate that important factors leading to hip instability are yet to be identified or the contributions of the measured variables are relatively small. Therefore, EUA should remain the main clinical determinant of hip stability status.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.