Are robotic-assisted and computer-navigated total hip arthroplasty associated with superior outcomes in patients who have hip dysplasia?

Introduction

Robotic-assisted (RA) and computer-navigated (CN) total hip arthroplasty (THA) have been demonstrated to improve component placement accuracy compared to manual THA (mTHA) for primary osteoarthritis. As hip dysplasia presents several additional challenges in component placement accuracy and leg length discrepancy (LLD) correction during THA, a systematic review was conducted to evaluate whether utilizing these platforms may be associated with superior outcomes over mTHA in patients who have hip dysplasia.

Methods

PubMed, Medline, EBSCOhost, and Google Scholar were searched on September 13, 2023 to identify comparative studies published after January 1, 2000 that evaluated outcomes of RA-THA or CN-THA in patients who have hip dysplasia. The query yielded 197 unique articles, which were screened for alignment with the study aims. After screening, 10 studies fulfilled all inclusion criteria, comprising 946 patients. Risk of bias was evaluated via the Methodological Index for Nonrandomized Studies tool, and the mean score was 21.2 ± 1.5.

Results

Both RA-THA and CN-THA were not associated with improved acetabular anteversion and inclination when evaluating Crowe I-IV types altogether compared to mTHA, but studies reported improved accuracy for each Crowe I and II cases when assessed individually. While studies reporting acetabular cup placement within the Lewinnek and Callanan safe zones consistently found higher odds of accurate positioning for RA-THA versus mTHA, accuracy in achieving targeted center of rotation was mixed. Also, studies reported no difference in LLD restoration for RA-THA and CN-THA compared to mTHA. While operative time may be increased when utilizing these platforms, they may also expedite specific sequences, offsetting most of the increase in operative time.

Conclusion

This review highlights the advantages of RA-THA and CN-THA for patients who have DDH, particularly when treating Crowe I and II types as superior radiographic outcomes were achieved with these intraoperative technologies. However, there remains a need for studies to investigate whether this results in patient-reported outcome measures.

Robotic-assisted total hip arthroplasty in patients with developmental dysplasia of the hip

PURPOSES

Due to the morphological diversity of deformities, technical difficulties, improperly designed components, and so on, THA remains a challenging task in dysplastic hips, especially in highly dislocated hips. The purpose of this study was to comprehensively evaluate the clinical outcomes of robot-assisted THA in patients with DDH through a large cohort study, including the precision of acetabular cup positioning, indicators of inflammatory response, indicators of muscle damage, and complications.

METHODS

We retrospectively analyzed patients with DDH who underwent THA in our prospectively constructed joint registry between August 2018 and August 2022. Finally, 147 manual THAs and 147 robotic-assisted THAs were included in the final analysis. Patient demographics, indicators of inflammation, indicators of muscle damage, operative time, Harris hip scores (HHS), and forgotten joint score (FJS) were recorded for analysis. The precision of the positioning of the acetabular component was assessed with plain radiographs.

RESULTS

In the Crowe II/III groups, the reconstructed center of rotation (COR) in the robotic-assisted group was closer to the anatomical COR with less variation than the manual group (absolute horizontal distances of COR 3.5 ± 2.8 vs. 5.4 ± 4.9 mm, p < 0.05; absolute vertical distances of COR 6.4 ± 4.1 vs. 11.7 ± 8.2 mm, p = 0.001). For all Crowe subtypes, the robotic-assisted THA significantly increased the proportion of acetabular cups located in the safety zone within 5° (all p < 0.05). Interleukin-6 and creatine kinase levels were slightly lower and significantly different in the robotic-assisted group at three days postoperatively (all p < 0.05).

CONCLUSIONS

Compared to the manual technique, the robot-assisted technique improved the precision and reproducibility of acetabular component positioning, particularly in DDH patients with Crowe types II/III. The robotic-assisted technique did not increase operative time, bleeding, complications, or revision rates, and had a slighter early inflammatory response and muscle damage.

Accuracy of portable navigation during THA in patients with severe developmental dysplasia of hip

INTRODUCTION

Correct cup placement in total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH) is considerably difficult. This study aimed to analyze the orientation accuracy of cup insertion during THA using a portable navigation system in patients with DDH.

MATERIALS AND METHODS

In this retrospective cohort study, we analyzed data from 64 patients who underwent THA using infrared stereo camera-matching portable navigation. Patients underwent THA via the anterolateral approach in the lateral decubitus position. Navigation records for intraoperative cup angles, postoperative cup angles measured on computed tomography (CT) images, and cup angle measurement differences were measured and compared between patients with non-DDH/mild DDH and severe DDH. Furthermore, the predictive factors for outliers of accurate acetabular cup placement were analyzed.

RESULTS

The average measurement absolute abduction differences (postoperative CT-navigation record) were 3.9 ± 3.5° (severe DDH) and 3.3 ± 2.6° (non-DDH/ mild DDH), and the anteversion differences were 4.7 ± 3.4° (severe DDH) and 2.3 ± 2.1° (non-DDH/ mild DDH). The anteversion difference was different between the two groups. Multivariate analysis showed that the navigation difference (absolute difference in anteversion between postoperative CT and navigation records of > 5°) was significantly associated with severe DDH (odds ratio [OR]: 3.3; p = 0.049, 95% confidence interval [CI]: 1.0-11.1) and posterior pelvic tilt (OR: 1.1; p = 0.042, 95% CI: 1.0-1.27).

CONCLUSIONS

In patients with severe DDH, it is important to pay close attention during THA using portable navigation. However, the average difference was < 5º even in patients with severe DDH, and the accuracy may be acceptable in a clinical setting when the cost is considered.

Why all newborn hip screening programs have same results-a mini review

All newborns are screened for developmental dysplasia of the hip (DDH), but countries have varying screening practices. The aim of this narrative mini review is to discuss the controversies of the screening and why it seems that all screening programs are likely to have same outcome. Different screening strategies are discussed alongside with other factors influencing DDH in this review. Universal ultrasound (US) has been praised as it finds more immature hips than clinical examination, but it has not been proven to reduce the rates of late-detected DDH or surgical management. Universal US screening increases initial treatment rates, while selective US and clinical screening have similar outcomes regarding late detection rates than universal US. This can be explained by the extrinsic factor affecting the development of the hip joint after birth and thus initial screening during the early weeks cannot find these cases.  Conclusion: It seems that DDH screening strategies have strengths and limitations without notable differences in the most severe outcomes (late-detected cases requiring operative treatment). Thus, it is important to acknowledge that the used screening policy is a combination of values and available resources rather than a decision based on clear evidence.

Pioneering a chick embryo model to explore the intrauterine etiology of developmental dysplasia of the hip in oligohydramnios conditions

OBJECTIVE

To explore the impact of oligohydramnios on fetal movement and hip development, given its association with developmental dysplasia of the hip (DDH) but unclear mechanisms.

METHODS

Chick embryos were divided into four groups based on the severity of oligohydramnios induced by amniotic fluid aspiration (control, 0.2 mL, 0.4 mL, 0.6 mL). Fetal movement was assessed by detection of movement and quantification of residual amniotic fluid volume. Hip joint development was assessed by gross anatomic analysis, micro-computed tomography (micro-CT) for cartilage assessment, and histologic observation at multiple time points. In addition, a subset of embryos from the 0.4 mL aspirated group underwent saline reinfusion and subsequent evaluation.

RESULTS

Increasing volumes of aspirated amniotic fluid resulted in worsening of fetal movement restrictions (e.g., 0.4 mL aspirated and control group at E10: frequency difference -7.765 [95% CI: -9.125, -6.404]; amplitude difference -0.343 [95% CI: -0.588, -0.097]). The 0.4 mL aspirated group had significantly smaller hip measurements compared to controls, with reduced acetabular length (-0.418 [95% CI: -0.575, -0.261]) and width (-0.304 [95% CI: -0.491, -0.117]) at day E14.5. Histological analysis revealed a smaller femoral head (1.084 ± 0.264 cm) and shallower acetabulum (0.380 ± 0.106 cm) in the 0.4 mL group. Micro-CT showed cartilage matrix degeneration (13.6% [95% CI: 0.6%, 26.7%], P = 0.043 on E14.5). Saline reinfusion resulted in significant improvements in the femoral head to greater trochanter (0.578 [95% CI: 0.323, 0.833], P = 0.001).

CONCLUSIONS

Oligohydramnios can cause DDH by restricting fetal movement and disrupting hip morphogenesis in a time-dependent manner. Timely reversal of oligohydramnios during the fetal period may prevent DDH.

In-hospital complications and readmission patterns in 13,937 patients with developmental dysplasia of the hip undergoing total hip arthroplasty: Evidence from the Chinese national database

PURPOSE

Clarifying the prognosis and readmission patterns of patients with developmental dysplasia of the hip (DDH) following total hip arthroplasty (THA) would provide important references for clinical management for this population. Using the Chinese national inpatient database (i.e., Hospital Quality Monitoring System [HQMS]), we aimed to compare in-hospital complications and readmission patterns following THA in patients with DDH and primary osteoarthritis (OA).

METHODS

Patients undergoing THA for DDH and OA between 2013 and 2019 were identified using the HQMS. Demographics and clinical characteristics were compared between the two groups. After propensity score matching, in-hospital complications and readmission patterns were compared using a logistic regression model.

RESULTS

According to the analysis of 13,937 propensity-score matched pairs, there were no significant differences in the incidence of in-hospital death (0.01 % vs 0.04 %, P = 0.142), transfusion (8.09 % vs 7.89 %, P = 0.536), wound infection (0.31 % vs 0.25 %, P = 0.364), deep venous thrombosis (0.45 % vs 0.43 %, P = 0.786), pulmonary embolism (0.03 % vs 0.05 %, P = 0.372) or all-cause readmission (2.87 % vs 3.12 %, P = 0.219) between two groups. However, DDH patients had higher surgical readmission rates than OA patients (1.43 % vs 1.14 %, P = 0.033). When analyzing causes of surgical readmission, DDH patients had increased risk of dislocation (0.37 % vs 0.21 %, P = 0.011) and aseptic loosening (0.17 % vs 0.07 %, P = 0.024) than OA patients.

CONCLUSION

DDH patients had an increased risk of surgical readmission following THA, mainly driven by dislocation and aseptic loosening, which should be recognized and appropriately prevented.

Preoperative Gallows traction as an adjunct to hip open reduction surgery: Is it safe and is it effective?

Background

Traction is used at our hospital before open reduction in infants with developmental dysplasia of the hip. Theoretically, it reduces soft-tissue tension, allowing an easier surgical reduction and therefore lower surgical complications. Owing to extended hospital stays, potential complications, and lack of evidence, the use of traction has decreased. This study aims to quantify whether traction is safe and whether it has any demonstrable effect.

Methods

The perioperative course of 80 patients undergoing preoperative traction and hip open reduction were reviewed. The height of hip dislocation was classified using the International Hip Dysplasia Institute classification system on both radiographs taken before and after traction. Any complications related to traction were recorded, along with the requirement for femoral shortening osteotomies, incidence of re-dislocation, and longer-term rate of avascular necrosis.

Results

Traction lowered the resting position of the majority of hips, with the median International Hip Dysplasia Institute grade before traction improving from 4 to 3, a statistically significant improvement (p < 0.00001). There were no neurovascular complications. Two babies were complicated with broken skin sores; however, surgery still progressed uneventfully. Zero hips in the cohort required femoral shortening osteotomies to achieve a tension-free reduction, and the re-dislocation rate was 0%. However, 96% of hips were Severin 1 or 2 at 6-year follow-up.

Conclusion

Notably, 1 week of preoperative traction significantly improves the resting position of the hip in high dislocations. It is safe when used in infants weighing <12 kg, and subsequent surgical outcomes are excellent, thus supporting its use ahead of developmental dysplasia of the hip open reduction surgery.

Level of evidence

Level IV.

Risk factor analysis of femoral avascular necrosis after operation for Tönnis grade IV developmental dysplasia of the hip

PURPOSE

We explored the risk factors for avascular necrosis (AVN) after surgery using open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV developmental dysplasia of the hip (DDH).

METHODS

In this retrospective study, we collected data of patients with Tönnis grade IV DDH treated with open reduction and pelvic osteotomy combined with femoral osteotomy from January 2012 to May 2020. The patients were divided into the AVN group and non-AVN group using the Kalamchi-MacEwen classification system. The clinical and imaging data of the two groups were collected, and the possible risk factors were included in the analysis. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors and odds ratios of AVN.

RESULTS

In all, 254 patients (mean age; 2.6±0.9 years, 278 hips) were included. The mean follow-up time was 3.8±1.5 years. A total of 89 hips (32%) were finally classified as AVN (Kalamchi-MacEwen II-IV). Univariate analysis showed significant associations with AVN for age (p=0.006), preoperative femoral neck anteversion (FAV) (p<0.001), femoral osteotomy length to dislocation height ratio (FDR) <1 (p<0.001), and the epiphyseal ossific nucleus diameter to the neck diameter ratio (ENR) <50% (p=0.009). Multivariate logistic regression analysis showed that only excessive preoperative FAV (OR: 1.04; 95% CI: 1.02-1.05; p<0.001) and FDR<1 (OR: 3.58; 95% CI: 2.03-6.31; p<0.001) were independent risk factors for femoral head necrosis.

CONCLUSION

Excessive preoperative FAV and FDR<1 are important risk factors for femoral AVN after open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV DDH. For children with DDH with high dislocation and excessive FAV, clinicians should fully evaluate their condition and design more personalized treatment programs to prevent AVN.

Enhancing YOLO5 for the Assessment of Irregular Pelvic Radiographs with Multimodal Information

Developmental dysplasia of the hip (DDH) is one of the most common orthopedic disorders in infants and young children. Accurate identification and localization of anatomical landmarks are prerequisites for the diagnosis of DDH. In recent years, various works have employed deep learning algorithms on radiography images for DDH diagnosis. However, none of these works have considered the incorporation of multimodal information. The pelvis exhibits distinct structures at different developmental stages, and there are also gender-based differences. In light of this, this study proposes a method to enhance the performance of deep learning models in diagnosing DDH by incorporating age and gender information into the channels. The study utilizes YOLO5 to construct a deep learning network for detecting hip joint landmarks. Moreover, a comprehensive dataset of 7750 pelvic X-ray images is established, covering ages from 4 months to 16 years and encompassing various conditions, such as deformities and post-operative cases, which authentically capture the temporal diversity and pathological complexities of DDH. Experimental results show that the YOLO5 model with integrated multimodal information achieves a mAP0.5-0.95 of 83.1% and a diagnostic accuracy of 86.7% in test dataset. The F1 scores for diagnosing cases of normal (NM), suspected dislocation (SD), mild dislocation (MD), and heavily dislocation (HD) are 90.9%, 79.8%, 63.5%, and 97.4%, respectively. Furthermore, experiments conducted on datasets of different sizes and networks of different sizes demonstrate the beneficial impact of multimodal information in improving the effectiveness of deep learning in diagnosing DDH.

Open reduction after failed closed reduction following failed Pavlik harness treatment in developmental dysplasia of the hip: One- or two-stage?

INTRODUCTION

The current published evidence for the treatment of developmental dysplasia of the hip (DDH) with failed closed reduction (CR) following failed Pavlik harness (PH) treatment is still limited. This study aimed to determine whether an one-stage open reduction (OR) would lead to a similar outcome to a two-stage OR in these patients. Meanwhile, the occurrence of femoral head avascular necrosis (AVN) and further surgery (pelvic osteotomy, PO) within the follow-up period was investigated.

MATERIALS AND METHODS

A consecutive series of DDH patients who failed CR following failed PH treatment and received OR finally between January 2008 and December 2020 were studied. The patients were divided into two groups. One group of which received OR immediately after failed CR (one-stage OR group, Group A), and the other received a delayed OR (two-stage OR group, Group B). The McKay's criteria, acetabular index (AI) and the degree of dislocation of the hips were evaluated for the final outcomes.

RESULTS

At the last follow-up, 54 (84.4%) of the 64 hips in Group A and 26 (83.9%) of 31 hips in Group B were in excellent or good condition. Comparison between the two groups revealed that there were no differences in terms of McKay grading (P = 0.950), AI (P = 0.783), incidence of AVN (P = 0.745), and also incidence of PO (P = 1.000). However, a significant lower mean AI was found in Group A, when the OR was performed in Group B (31.06 ± 4.45° vs. 33.87 ± 4.12°, P = 0.004).

CONCLUSION

Both of the one- and two-stage OR may acheive favorable outcomes. Moreover, one-stage OR is of without the general anesthesia risk associated with two-stage OR. We therefore advocate that an OR should be performed in appropriate DDH patients during the same session once a failed CR is detected.

Mid-term results of total hip arthroplasty with anatomical ultra-short cementless stem in patients with developmental dysplasia of the hip Crowe type II

The aim of this study was to present the mid-term results of ultra-short cementless stem total hip arthroplasty (THA) in patients with Crowe type II developmental dysplasia of the hip. The study consists of 68 patients (75 THAs) with a Proxima stem implanted between 2006 and 2015. The clinical results include Harris Hip Scores. Radiological follow-up reports on stem migration, bony trabecular development and radiolucent lines. Kaplan-Meier survival analysis was performed. The mean age of patients was 48.4 years, with a mean follow-up 114 months. The average Harris Hip Score improved significantly from 45.1 preoperatively to 97.6 at the final evaluation (p < 0.001). Stem migration was observed in five hips (in all of them up to the 6th postoperative month, without any further progression of migration or radiological loosening). Bony trabecular development was detected in modified Gruen zones (1, 2, 4, 6, 7 for Proxima stem): in zone 1 (0%), 2 (49.3.0%), 4 (38.7%), 6 (82.7%), 7 (0%). Radiolucent lines were observed around one cup (DeLee and Charnley zone I) and three stems (none was loose, all three with fibrous stable fixation). Complications were found in three hips (4.0%): intraoperative periprosthetic femoral fracture (threated with cerclage wire) in two hips and squeezing hip in one patient (with perioperative ceramic inlay breakage and exchange). No hip was revised. The implant survival was 100.0% both clinically and radiologically. Observations in the mean follow-up of 114 months show that the results (clinical and radiological) of the Proxima stem in patients with Crowe type II DDH are promising.

Single-nucleus RNA and multiomics in situ pairwise sequencing reveals cellular heterogeneity of the abnormal ligamentum teres in patients with developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is the most common hip deformity in pediatric orthopedics. One of the common pathological changes in DDH is the thickening and hypertrophy of the ligamentum teres. However, the underlying pathogenic mechanism responsible for these changes remains unclear. This study represents the first time that the heterogeneity of cell subsets in the abnormal ligamentum teres of patients with DDH has been resolved at the single-cell and spatial levels by snRNA-Seq and MiP-Seq. Through gene set enrichment and intercellular communication network analyses, we found that receptor-like cells and ligament stem cells may play an essential role in the pathological changes resulting in ligamentum teres thickening and hypertrophy. Eight ligand-receptor pairs related to the ECM-receptor pathway were observed to be closely associated with DDH. Further, using the Monocle R package, we predicted a differentiation trajectory of pericytes into two branches, leading to junctional ligament stem cells or fibroblasts. The expression of extracellular matrix-related genes along pseudotemporal trajectories was also investigated. Using MiP-Seq, we determined the expression distribution of marker genes specific to different cell types within the ligamentum teres, as well as differentially expressed DDH-associated genes at the spatial level.

Treatment of bilateral developmental dysplasia of the hip joint with an improved technique: A case report

BACKGROUND

Developmental dysplasia of the hip (DDH) is a common osteoarticular deformity in pediatric orthopedics. A patient with bilateral DDH was diagnosed and treated using our improved technique "(powerful overturning acetabuloplasty)" combined with femoral rotational shortening osteotomy.

CASE SUMMARY

A 4-year-old girl who was diagnosed with bilateral DDH could not stand normally, and sought surgical treatment to solve the problem of double hip extension and standing. As this child had high dislocation of the hip joint and the acetabular index was high, we changed the traditional acetabuloplasty to "powerful turnover acetabuloplasty" combined with femoral rotation shortening osteotomy. During the short-term postoperative follow-up (1, 3, 6, 9, 12, and 15 months), the child had no discomfort in her lower limbs. After the braces and internal fixation plates were removed, formal rehabilitation training was actively carried out.

CONCLUSION

Our "powerful overturning acetabuloplasty" combined with femoral rotational shortening osteotomy is feasible in the treatment of DDH in children. This technology may be widely used in the clinic.

COL11A1 is associated with developmental dysplasia of the hip and secondary osteoarthritis in the HUNT study

Objective

Developmental dysplasia of the hip (DDH) is a congenital condition affecting 2-3% of all infants. DDH increases the risk of osteoarthritis, is the cause of 30 ​% of all total hip arthroplasties (THAs) in adults <40 years of age and can result in loss of life quality. Our aim was to explore the genetic background of DDH in order to improve diagnosis, management and longterm outcome.

Design

We used the large, ongoing, longitudinal Trøndelag Health Study (HUNT) database. Case definition was based on ICD-9/-10 diagnoses of DDH, or osteoarthritis secondary to DDH. Analyses were performed using SAIGE software, with covariates including sex, batch, birth year and principal components. We included only single nucleotide polymorphisms (SNPs) with minor allele frequency (MAF) ≥ 0.01, R2≥ 0.8 and Hardy-Weinberg equilibrium (HWE) P-value ≥ 0.0001. Significance level was set at p ​< ​5 ​× ​10-8. Meta-analysis using data from DDH and primary osteoarthritis genome-wide association studies (GWASs) was done using METAL software. The study was approved by the regional ethical committee.

Results

Analysis included 69,500 individuals, of which 408 cases, and 8,531,386 SNPs. Two SNPs near COL11A1 were significantly associated with DDH; rs713162 (β  ​= ​-0.43, SE ​= ​0.07, p ​= ​8.4 ​× ​10-9) and rs6577334 (β  ​= ​-0.43, SE ​= ​0.08, p ​= ​8.9 ​× ​10-9). COL11A1 has previously been associated with acetabular dysplasia and osteoarthritis. Meta-analysis supported previous GWAS findings of both DDH and primary osteoarthritis.

Conclusions

This large, genome-wide case-control study indicates an association between COL11A1 and DDH and is an important contribution to investigating the etiology of DDH, with further research needed.

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.

Augmented reality-guided pelvic osteotomy of Ganz: feasibility in cadavers

INTRODUCTION

The periacetabular osteotomy is a technically demanding procedure with the goal to improve the osseous containment of the femoral head. The options for controlled execution of the osteotomies and verification of the acetabular reorientation are limited. With the assistance of augmented reality, new possibilities are emerging to guide this intervention. However, the scientific knowledge regarding AR navigation for PAO is sparse.

METHODS

In this cadaveric study, we wanted to find out, if the execution of this complex procedure is feasible with AR guidance, quantify the accuracy of the execution of the three-dimensional plan, and find out what has to be done to proceed to real surgery. Therefore, an AR guidance for the PAO was developed and applied on 14 human hip cadavers. The guidance included performance of the four osteotomies and reorientation of the acetabular fragment. The osteotomy starting points, the orientation of the osteotomy planes, as well as the reorientation of the acetabular fragment were compared to the 3D planning.

RESULTS

The mean 3D distance between planned and performed starting points was between 9 and 17 mm. The mean angle between planned and performed osteotomies was between 6° and 7°. The mean reorientation error between the planned and performed rotation of the acetabular fragment was between 2° and 11°.

CONCLUSION

The planned correction can be achieved with promising accuracy and without serious errors. Further steps for a translation from the cadaver to the patient have been identified and must be addressed in future work.

Long-term course of developmental dysplasia of the hip: follow-up of the non-operated hips of patients undergoing unilateral rotational acetabular osteotomy for twenty-four years

PURPOSE

To follow-up the non-operated hips of patients who underwent unilateral rotational acetabular osteotomy (RAO) for bilateral developmental dysplasia of the hip (DDH) for a minimum of 20 years to clarify (1) the timing of onset of hip osteoarthritis (OA) in DDH, and (2) factors associated with the development of OA.

METHODS

This study included 92 non-operated hips of patients who underwent unilateral RAO for bilateral DDH. We examined the timing of OA onset and total hip arthroplasty (THA) and the joint survival rate in the studied hips. Furthermore, the patients were divided into those with OA onset (progression group) and those without OA onset and compared in terms of lateral center-edge angle (LCEA), sharp angle, acetabular head index (AHI), acetabular roof obliquity (ARO), joint congruity, and the presence or absence of OA progression on the RAO side.

RESULTS

The progression group experienced OA onset 12 years after RAO and underwent THA 6 years after OA onset. The 20-year joint survival rate was 73% with the endpoint of OA onset and 81% with the endpoint of THA. The progression group had significantly smaller LCEA and AHI and larger ARO. The risk of developing OA was 8.2 times greater in patients with LCEA ≤ 7° than in those with LCEA > 7°.

CONCLUSION

The patients with OA progression group experienced OA onset at an average age of 55 years. A small LCEA (≤ 7°) was identified as a risk factor for the development of OA.

Periacetabular osteotomy for symptomatic hip dysplasia in middle aged patients: does age alone matter?

BACKGROUND

Conflicting evidence exists regarding outcomes in middle-aged patients undergoing periacetabular osteotomy (PAO) for symptomatic developmental dysplasia of the hip (DDH).

AIMS

To compare patient reported outcomes (PROMs) of middle-aged PAO patients with younger patient groups.

METHODS

Retrospective analysis of prospectively collected data of PAO patients between 01/2015 and 06/2017 at a single orthopedic university center with a primary diagnosis of symptomatic DDH. The cohort was divided into four age groups and compared: < 20, 20-30, 30-40 and > 40 years. Joint function was assessed using iHOT-12, mHHS and SHV. Activity level was assessed using UCLA Activity score. Patient satisfaction and pain were assessed on the numerical rating scale 0-10. Conversion rates to THA were assessed.

RESULTS

Out of 202 PAOs, 120 cases with complete data were included. Mean follow-up was 63 months (range 47-81 months). Eighteen patients were < 20 years old, 54 were 20-30 years, 37 were 30-40 years, 11 patients were older than 40. No significant differences were observed for preoperative or postoperative iHOT-12 (p = 0.898; p = 0.087), mHHS (p = 0.878; p = 0.103), SHV (p = 0.602; p = 0.352) or UCLA (p = 0.539; p = 0.978) between groups. Improvement deltas were also not significantly different for all PROMs. Postoperative patient satisfaction was similar between groups (p = 0.783).

CONCLUSION

Patients with symptomatic DDH may benefit from PAO even at middle age with similar outcomes and pre- to postoperative improvements as younger age groups. Indication should be based on biological age and preoperative joint condition rather than age.

Comparison of clinical and radiological outcomes for the anterior and medial approaches to open reduction in the treatment of bilateral developmental dysplasia of the hip: a systematic review protocol

BACKGROUND

Developmental dysplasia of the hip (DDH) affects 1-3% of newborns and 20% of cases are bilateral. The optimal surgical management strategy for patients with bilateral DDH who fail bracing, closed reduction or present too late for these methods to be used is unclear. There are proponents of both medial approach open reduction (MAOR) and anterior approach open reduction (AOR); however, there is little evidence to inform this debate.

METHODS

We will perform a systematic review designed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol. We will search the medical and scientific databases including the grey and difficult to locate literature. The Medical Subject Headings "developmental dysplasia of the hip", "congenital dysplasia of the hip", "congenital hip dislocation", "developmental hip dislocation", and their abbreviations, "DDH" and "CDH" will be used, along with the qualifier "bilateral". Reviewers will independently screen records for inclusion and then independently extract data on study design, population characteristics, details of operative intervention and outcomes from the selected records. Data will be synthesised and a meta-analysis performed if possible. If not possible we will analyse data according to Systematic Review without Meta-Analysis guidance. All studies will be assessed for risk of bias. For each outcome measure a summary of findings will be presented in a table with the overall quality of the recommendation assessed using the Grading of Recommendations Assessment Development and Evaluation approach.

DISCUSSION

The decision to perform MAOR or AOR in patients with bilateral DDH who have failed conservative management is not well informed by the current literature. High-quality, comparative studies are exceptionally challenging to perform for this patient population and likely to be extremely uncommon. A systematic review provides the best opportunity to deliver the highest possible quality of evidence for bilateral DDH surgical management.

SYSTEMATIC REVIEW REGISTRATION

The protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42022362325).

Risk factors of developmental dysplasia of the hip in infants: A meta-analysis based on cohort studies

INTRODUCTION

Developmental dysplasia of the hip (DDH) is a prevalent condition in children. Currently, the exact etiology of DDH remains uncertain. The objective of this study was to conduct a meta-analysis to investigate the risk factors associated with DDH in infants. The findings would provide a theoretical foundation for targeted early screening and diagnosis.

HYPOTHESIS

Several indicators, such as gender, intrauterine position, family history of DDH, gestational age, delivery mode, amniotic fluid levels, swaddling, parity, fetus number, combined musculoskeletal deformities, birth weight, and physical examination results, may serve as risk factors for DDH.

MATERIALS AND METHODS

Cohort studies investigating the risk factors of DDH in infants through logistic regression analysis were searched in the Wanfang, VIP citation, China National Knowledge Infrastructure (CNKI), China Biology Medicine disc, Excerpta Medica Database (Embase), PubMed, and Cochrane Library databases up to May 2023. After extracting the data from eligible literature and assessing them using the Newcastle-Ottawa Scale (NOS), articles were selected based on pre-established inclusion and exclusion criteria.

RESULTS

A total of eleven literature reports covering 979,757 infants were included in this meta-analysis. The publication bias did not significantly influence the results. The incidence rate of DDH was 47.99‰ among infants with risk factors compared to 3.21‰ in the general population. Risk factors for DDH included being female (OR=6.97, 95% CI: 5.18-9.39, p<0.001), breech delivery (OR=4.14, 95% CI: 3.09-5.54, p<0.001), positive family history (OR=4.07, 95% CI: 2.20-7.52, p<0.001), cesarean section (OR=1.11, 95% CI: 1.01-1.21, p=0.032), oligohydramnios (OR=3.93, 95% CI: 1.29-12.01, p=0.016), swaddling (OR=6.74, 95% CI: 1.25-36.31, p=0.026), firstborn status (OR=1.84, 95% CI: 1.49-2.53, p<0.001), combined musculoskeletal malformations (OR=2.27, 95% CI: 1.58-3.27, p<0.001), and physical signs of DDH (OR=8.71, 95% CI: 2.44-31.07, p=0.001). Premature delivery (OR=0.91, 95% CI: 0.88-0.95, p<0.001) was a protective factor for DDH. The relationship between multiple pregnancies (OR=0.58, 95% CI: 0.33-1.02, p=0.060) and low birth weight (OR=0.62, 95% CI: 0.14-2.76, p=0.529) in relation to DDH remained uncertain.

DISCUSSION

This meta-analysis shows that female, breech delivery, positive family history, cesarean section, firstborn status, oligohydramnios, swaddling and combined musculoskeletal malformations are associated with DDH. Premature delivery appeared to be a protective factor against DDH. Nevertheless, the other factors need more research to reach more conclusive results.

LEVEL OF EVIDENCE

III; meta-analysis.

Transgluteal Ultrasonography in Spica Cast in the Post-reduction Assessment of Hip Developmental Dysplasia

OBJECTIVE

Concentric circle reduction is one of the outcomes after reduction of developmental dysplasia of the hip (DDH). Radiography and magnetic resonance imaging (MRI) are used to confirm the reduction results. In this study, we evaluated the reduction results of the coronal section of the hip using transgluteal ultrasonography.

METHODS

We enrolled 46 children admitted to our hospital for closed or open reduction plaster fixation of DDH between January 2021 and December 2022. Thirty-eight patients had unilateral DDH, and eight patients had bilateral DDH. Transgluteal ultrasonography, radiography and MRI were done on the patients during the 7 d after reduction, and the results were interpreted by different radiologists. The covering of the femoral head and the distance between the medial margin of the femoral head and the acetabulum (HSD) were measured after calculating the maximum coronal surface of the iliac bone. MRI is regarded as the gold standard for determining hip reduction or dislocation. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ultrasound and radiography were determined and compared.

RESULTS

The sensitivity, specificity, PPV and NPV of transgluteal ultrasonography were 100% (confidence interval [CI]: 69.2%-100%), 97.7% (CI: 88%-99.9%), 90.9% (CI: 59%-98.6%) and 100%, respectively, higher than those of radiography, which were 50% (CI: 18.7%-81.3%), 86.4% (CI: 72.6%-94.8%), 45.5% (CI: 24%-68.7%) and 88.4% (CI: 80.2%-93.5%), respectively. Ultrasonography had a higher sensitivity (100% vs. 50%, p < 0.01) and positive predictive rate (90.9% vs. 45.5%, p < 0.01) than radiography. Ultrasonography revealed that a distance between the head and socket (HSD) >8 mm indicated a strong suspicion for a poor reduction.

CONCLUSION

Transgluteal coronal ultrasound scan with semiquantitative assessment of acetabular femoral head coverage and measurement of HSD can effectively monitor the reduction relationship between the two in children after DDH reduction.

Length of treatment and ultrasound timing in infants with developmental dysplasia of the hip

PURPOSE

Developmental dysplasia of the hip (DDH) joint is a complex condition that may lead to severe problems. Ultrasound scan (USS) in the first four-to-six weeks of life is considered the gold-standard for diagnosis while the Pavlik harness (PH) is a widely utilized method as first-line treatment. The purpose of this study is to compare clinical outcomes of infants with DDH in relation to the timing and frequency of USS following application of the PH.

METHODS

Retrospective data were collected over a 5-year period from February 2017 to February 2022. We included patients who underwent the first USS post-diagnosis and PH application in two, three, four and six weeks. Two-hundred-twenty-five patients were included and divided in four groups according to timing of the first follow-up: week-2, n = 13; week-3, n = 66; week-4, n = 95; and week-6, n = 51. For every patient Graf classification, treatment length and number of follow-ups were documented.

RESULTS

Week-3 and week-4 groups displayed a statistically significant shorter treatment length compared to week-6 group (p value < 0.001), while also demonstrating a lower number of sonographic follow-ups per patient compared to both week-6 (p value < 0.001) and week-2 (p value = 0.002 vs week-3; p value < 0.001 vs week 4). Week-4 group presented the highest treatment completion (56%) on first visit post-diagnosis. Conservative treatment with PH failed in 1.8% (4/225) and displayed no significant difference among all subgroups.

CONCLUSIONS

Differences in timing of first USS post-DDH diagnosis and initiation of treatment can lead to discrete outcomes with implications to the clinical outcome and cost effectiveness.

Effect of the Pavlik harness used in the treatment of developmental dysplasia of the hip on unaided sitting and independent walking age

Background

Pavlik harness is the most widely used orthosis in the treatment of developmental dysplasia of the hip. The aim of this study was to evaluate the effect of the Pavlik harness on the development of "unaided sitting" and "independent walking" in infants with developmental dysplasia of the hip.

Methods

This prospective study, conducted from 2017 to 2020, included infants undergoing Pavlik harness therapy. Inclusion criteria comprised gestational age > 37 weeks, treatment initiation before 6 months of age, and no prior treatment for developmental dysplasia of the hip. We assessed treatment initiation age, treatment duration, and the age of achieving unaided sitting and independent walking.

Results

In the patient group, unaided sitting commenced at a mean age of 6.8 ± 1.6 (range: 4-11) months, while independent walking began at a mean age of 12.7 ± 1.8 (range: 9-18) months. By 15 months, 92% of the patients achieved independent walking. In the control group, unaided sitting occurred at a mean age of 6.1 ± 1.1 (range: 4-8) months, and independent walking at 11.8 ± 1.6 (range: 9-18) months. A significant positive correlation was observed between the duration of Pavlik harness usage and the age of unaided sitting (p < 0.001) and independent walking (p < 0.001).

Conclusion

Our study indicates that Pavlik harness treatment for developmental dysplasia of the hip is generally safe and does not lead to clinically significant delays in unaided sitting and independent walking. However, some minor delays may occur due to extended orthosis use.

Level of evidence

level III-prospective cohort study.

Ultrasonographic screening for developmental dysplasia of the hip: the Graf method revisited

Until the 1980s, the diagnosis of developmental dysplasia of the hip (DDH) was based on clinical examination and radiographic imaging. In 1980, Reinhard Graf developed his own ultrasonographic method for the examination of the infant hip joint. Graf's method evaluates the osseous and cartilaginous coverage of the femoral head by the acetabulum in the infantile hip joint by measuring the angles α and β. The validity of Graf method is that with these measurements the hip joint is further classified by Graf classification into types I to IV that guide treatment. Currently, Graf method is considered the gold standard examination for the diagnosis of DDH in many European countries. This review article aims to discuss the incidence, risk factors and pathophysiology of DDH, and to emphasize on the Graf method for the evaluation, classification, prevention and further management of this entity.

Pain, function and quality of life are impaired in adults undergoing periacetabular osteotomy (PAO) for hip dysplasia: a systematic review and meta-analysis

BACKGROUND

Hip dysplasia is a common condition in active adults with hip pain that can lead to joint degeneration. Periacetabular osteotomy (PAO) is a common surgical treatment for hip dysplasia. The effect of this surgery on pain, function and quality of life (QOL) has not been systematically analysed.

PURPOSE

In adults with hip dysplasia: (1) evaluate differences in pain, function and QOL in those undergoing PAO and healthy controls; (2) evaluate pre- to post-PAO changes in pain, function and QOL; (3) evaluate differences in pain, function and QOL in those with mild versus severe dysplasia, undergoing PAO; and (4) evaluate differences in pain, function and QOL in those having primary PAO versus those with previous hip arthroscopy.

METHODS

A comprehensive, reproducible search strategy was performed on 5 different databases. We included studies that assessed pain, function and QOL in adults undergoing PAO for hip dysplasia, using hip-specific patient reported outcomes measures.

RESULTS

From 5017 titles and abstracts screened, 62 studies were included. Meta-analysis showed PAO patients had worse outcomes pre- and post-PAO compared to healthy participants. Specifically, pain (standardised mean difference [SMD] 95% confidence interval [CI]): -4.05; -4.78 to -3.32), function (-2.81; -3.89 to -1.74), and QOL (-4.10; -4.43 to -3.77) were significantly poorer preoperatively.Meta-analysis found patients experienced improvements following PAO. Pain improved from pre-surgery to 1-year (standardised paired difference [SPD] 1.35; 95% CI, 1.02-1.67) and 2 years postoperatively (1.35; 1.16-1.54). For function, the activities of daily living scores at 1 year (1.22; 1.09-1.35) and 2 years (1.06; 0.9-1.22) and QOL at 1 year (1.36; 1.22-1.5) and 2 years (1.3; 1.1-1.5) all improved. No difference was found between patients undergoing PAO with mild versus severe dysplasia.

CONCLUSIONS

Before undergoing PAO surgery, adults with hip dysplasia have worse levels of pain, function and QOL compared to healthy participants. These levels improve following PAO, but do not reach the same level as their healthy participants.

REGISTRATION

PROSPERO (CRD42020144748).

Ultra-long-term results of the Chiari pelvic osteotomy in hip dysplasia patients: a minimum of thirty-five years follow-up

PURPOSE

The Chiari pelvic osteotomy was the first surgical procedure to address hip dysplasia by changing the position of the acetabulum by medialization, thus creating a bony roof and improving biomechanical conditions. The aim of this retrospective cohort study was to report on the very long-term results of this technique.

METHODS

Out of a consecutive series of 1536 hips, 504 in 405 patients were available for follow-up. The patients were assessed by physical and radiological examination. A Kaplan-Meier survival analysis with total hip arthroplasty as an endpoint was performed and stratified for age groups, pre-operative diagnosis, sex and osteoarthritis stage.

RESULTS

The average follow-up was 36 ± 8.1 years (range, 35.2 to 54). The average pain level on the Visual Analogue Scale was 2.9 ± 2.6 (range 0 to 8.7). The average Harris Hip Score was 80.2 ± 17.4 (range 17.4 to 100). Correction of dysplasia was effective and remained stable over time. Osteoarthritis significantly increased over time with 53% Tönnis grade 3 at follow-up. The cumulative survivorship was 79.8% (95% confidence interval (CI), 76.1-83.2%) at 20 years, 57.1% (95% CI, 52.8-61.8%) at 30 years and 35% (95% CI, 30.3-40.3%) at 40 years. Young age, male sex and low osteoarthritis grade were positive prognostic factors.

CONCLUSIONS

Although the Chiari pelvic osteotomy is considered a salvage procedure nowadays, it achieved excellent long-term results even in indications, which would be treated differently today. Young patients without osteoarthritis had the best outcome.

The outcomes of total hip arthroplasty in developmental dysplasia of hip versus osteoarthritis: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to compare the outcomes of total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH) and those with osteoarthritis (OA).

METHODS

Four databases were searched from inception till February 2023 for original studies that compared the outcomes of THA in DDH and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and failure modes (i.e. aseptic loosening, PJI, instability, and periprosthetic fractures), hospital stay and costs. This review was conducted as per PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 9 observational studies with 575,255 THA (469,224 hips) were included, with a mean age of 50.6 years and 62.1 years for DDH and OA groups, respectively. There was a statistically significant difference in revision rate between DDH and OA patients in favour of OA (OR, 1.66; 95% CI 1.11-2.48; p-value, 0.0251). However, dislocation rate (OR, 1.78, 95% CI 0.58-5.51; p-value, 0.200), aseptic loosening (OR, 1.69; 95% CI 0.26-10.84; p-value, 0.346) and PJI (OR, 0.76; 95% CI 0.56-1.03; p-value, 0.063) were comparable across both groups.

CONCLUSION

A higher revision rate following total hip arthroplasty was associated with DDH compared with osteoarthritis. However, both groups had similar dislocation rates, aseptic loosening and PJI. Consideration of confounding factors, such as patient age and activity level, is crucial when interpreting these findings. LEVEL OF EVIDENCE : III.

TRIAL REGISTRATION

PROSPERO registration: CRD42023396192.

An Eastern Europe and Middle East multinational expert Delphi consensus study on the prevention, diagnosis, and treatment of developmental dysplasia of the hip before walking age

PURPOSE

The incidence of developmental dysplasia of the hip (DDH) is higher in Eastern Europeans and Middle Easterners. This study aimed to establish consensus among experts in this geographical area on the management of DDH before walking age.

METHODS

Fourteen experienced orthopedic surgeons agreed to participate in a four-round online consensus panel by the Delphi method. The questionnaire included 31 statements concerning the prevention, diagnosis, and treatment of DDH before walking age.

RESULTS

Consensus was established for 26 (84%) of 31 statements. Hip ultrasonography is the proper diagnostic tool under six months in DDH; universal newborn hip screening between three and six weeks is necessary; positive family history, breech presentation, female gender, and postnatal swaddling are the most important risk factors; Ortolani, Barlow tests, and limitation of abduction are the most important clinical findings; Pavlik harness is the first bracing preference; some Graf type IIa hips and all Graf type IIb and worse hips need abduction bracing treatment; the uppermost age limit for closed and open reductions is 12 months and 12-24 months, respectively; anatomic reduction is essential in closed and open reductions, postoperative MRI or CT is not always indicated; anterior approach open reduction is better than medial approach open reduction; forceful reduction and extreme positioning of the hips (> 60° hip abduction) are the two significant risk factors for osteonecrosis of the femoral head.

CONCLUSION

The findings of the present study may be useful for clinicians because a practical reference, based on the opinions of the multinational expert panel, but may not be applicable to all settings is provided.

[Advances in revision surgery after primary total hip arthroplasty for Crowe type developmental dysplasia of the hip]

Objective

To review research advances of revision surgery after primary total hip arthroplasty (THA) for patients with Crowe type Ⅳ developmental dysplasia of the hip (DDH).

Methods

The recent literature on revision surgery after primary THA in patients with Crowe type Ⅳ DDH was reviewed. The reasons for revision surgery were analyzed and the difficulties of revision surgery, the management methods, and the related prosthesis choices were summarized.

Results

Patients with Crowe type Ⅳ DDH have small anteroposterior diameter of the acetabulum, large variation in acetabular and femoral anteversion angles, severe soft tissue contractures, which make both THA and revision surgery more difficult. There are many reasons for patients undergoing revision surgery after primary THA, mainly due to aseptic loosening of the prosthesis. Therefore, it is necessary to restore anatomical structures in primary THA, as much as possible and reduce the generation of wear particles to avoid postoperative loosening of the prosthesis. Due to the anatomical characteristics of Crowe type Ⅳ DDH, the patients have acetabular and femoral bone defects, and the repair and reconstruction of bone defects become the key to revision surgery. The acetabular side is usually reconstructed with the appropriate acetabular cup or combined metal block, Cage, or custom component depending on the extent of the bone defect, while the femoral side is preferred to the S-ROM prosthesis. In addition, the prosthetic interface should be ceramic-ceramic or ceramic-highly cross-linked polyethylene wherever possible.

Conclusion

The reasons leading to revision surgery after primary THA in patients with Crowe type Ⅳ DDH and the surgical difficulties have been clarified, and a large number of clinical studies have proposed corresponding revision modalities based on which good early- and mid-term outcomes have been obtained, but further follow-up is needed to clarify the long-term outcomes. With technological advances and the development of new materials, personalized prostheses for these patients are expected to become a reality.

Risk factors for a false negative Ortolani and Barlow examination in developmental dysplasia of the hip

INTRODUCTION

Although universal screening by neonatal clinical examination with Ortolani and Barlow manoeuvres is widely adopted, its role as a sole screening tool is controversial due to its poor sensitivity and failure in identifying hip joints that eventually require surgical intervention.

HYPOTHESIS

This study aims to identify risk factors for a false negative Ortolani and Barlow examination in neonatal screening for DDH. The hypothesis is that risk factors for developmental dysplasia of the hips could similarly be risk factors for a false negative Ortolani and Barlow examination.

MATERIAL AND METHODS

In the 14-year retrospective cohort study, all newborn infants born in a single institution from 1st January 1999 to 31st December 2013 were screened clinically with the Ortolani/Barlow manoeuvre by a neonatologist. Infants with positive risk factors, despite a normal clinical examination, were then scheduled for bilateral hip ultrasound in the first three months of life and evaluated according to the Graf's method, Harcke's method of dynamic ultrasound screening and Terjesen's method of evaluation for femoral head coverage.

RESULTS

A total of 164 infants with normal Ortolani and Barlow examinations were scheduled for bilateral hip ultrasound due to the presence of risk factors. Amongst these, 32 (19.5%) infants were evaluated to have an abnormal hip on ultrasound. Breech position was the only statistically significant risk factor for a false negative Ortolani/Barlow examination (14/34, 41.2% vs. 18/112, 13.8%; p<0.001).

DISCUSSION

Sonographic hip examinations are recommended for all infants with breech presentation even if they have a normal Ortolani and Barlow examination.

LEVEL OF EVIDENCE

III; case-control study.

Analysis of 900 patients

BACKGROUND

Developmental dysplasia of the hip (DDH) is a disorder of hip development that leads to dysplasia, subluxation, or total hip dislocation. Early detection of DDH is important, and early initiation of abduction treatment is key to successful correction of the hip joint. However, mild forms of DDH, including hip instability without complete dislocation, have good spontaneous healing potential, and a watchful waiting strategy in mild DDH has been found to be safe. In this study, we aimed to evaluate the cost differences between different treatment strategies for DDH.

MATERIAL AND METHODS

Data were collected retrospectively from the medical records of all children diagnosed with diagnosis and treatment of DDH in Tampere University hospital between 1998 and 2018. In total, 948 patients were included in the study. Patients who underwent casting or operative treatment (n = 48) were excluded from the analysis. All Ortolani positive children were subjected to early abduction treatment. Children with Ortolani negative DDH were subjected to either watchful waiting or early abduction treatment, based on the clinicians' decision. The regression model estimates for the number of clinical visits with and without ultrasound examination were assessed together with cost reports from Tampere University Hospital for the calculation of savings per patient in spontaneous recovery.

RESULTS

Alpha angles at one month of age (p < 0.001) and treatment method (p < 0.001) affected the number of clinical visits and ultrasound examinations during the treatment follow-up. A low alpha angle predicted closer follow-up, and children with spontaneous recovery had lower numbers of clinical visits and ultrasound examinations than children in abduction treatment. Spontaneous recovery was found to result in approximately 375€/patient savings compared to successful abduction treatment.

CONCLUSION

With correct patient selection, a watchful waiting strategy is cost-effective in treating mild developmental dysplasia of the hip, considering the high percentage of spontaneous recovery.

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.

Femoral head translation in borderline and definite dysplastic hips during weight-bearing: 2D/3D image registration analysis

PURPOSE

The aims of this study were to 1) assess femoral head translation during weight-bearing in symptomatic developmental dysplasia of the hip (DDH) and 2) compare it between borderline DDH and definite DDH.

METHODS

The study included four individuals with borderline DDH and nine with definite DDH, scheduled for periacetabular osteotomy. Anteroposterior X-ray images of the hip joint were obtained in the standing position, and computed tomography images of the pelvis were obtained in the supine position. Femoral head translation from the supine to a standing position was measured using 2D/3D X-ray image registration.

RESULTS

From a supine to a standing position, the femoral head translated 0.3 mm laterally, 0.5 mm anteriorly, and 0.5 mm superiorly on average. The mean femoral head translation in 3D between the supine and standing positions was 1.5 mm. The 3D femoral head translation in the borderline DDH group was significantly greater than that in the definite DDH group. In the definite DDH group, there was a significant correlation between the center edge (CE) angle and 3D femoral head translation (ρ = -0.78, P = 0.012).

CONCLUSIONS

Symptomatic DDH showed femoral head translation in the anterior, lateral, and superior directions during weight-bearing. In definite DDH, the amount of femoral head translation was negatively correlated with the CE angle. The amount of 3D translation in patients with borderline DDH was larger than that in definite DDH. Dynamic joint instability during weight-bearing was observed in borderline DDH as well as definite DDH. Treatment to enhance joint stability during weight-bearing is important in both cases.

Transverse subtrochanteric shortening osteotomy with double tension-band fixation during THA for Crowe III-IV developmental dysplasia: 12-year outcomes

BACKGROUND

When performing total hip arthroplasty in patients with severe developmental dysplasia, shortening the femur facilitates reduction while also preventing sciatic or crural nerve injury and excessive length of the operated limb. No consensus exists about the optimal type of implant and best internal fixation procedure, two parameters that directly govern the risk of the most common intraoperative and postoperative complications (diaphyseal fractures, dislocation, non-union). To minimise these risks, we developed a technique combining a transverse subtrochanteric shortening osteotomy, a long ovoid-profiled, cementless stem anchored in the metaphysis, and double tension-band wiring for internal fixation. The primary objective of this study was to evaluate the outcomes of this technique with emphasis on (i) complications and femoral implant survival, (ii) clinical outcomes (functional scores and lower-limb length inequality [LLLI]), and time to healing.

HYPOTHESIS

Our technique is associated with low rates of intraoperative and postoperative complications.

MATERIAL AND METHODS

This single-centre retrospective cohort study included patients who underwent THA with a transverse subtrochanteric shortening osteotomy and fixation using double tension-band wiring to treat severe (Crowe III or IV) developmental hip dysplasia. The femoral implant was a long, ovoid, cementless stem fully coated with hydroxyapatite. We collected the intraoperative and postoperative complications, survival, LLLI, functional scores (Harris Hip Score [HHS] and Forgotten Joint Score [FJS]), patient satisfaction, and radiographic outcomes.

RESULTS

The study included 31 hips in 25 patients. Two patients (2/31 hips, 6.5%) were lost to follow-up, leaving 29 hips for the analysis of postoperative outcomes. Mean follow-up was 13.7±4.2 years (range, 5.8-18.3 years). The four intraoperative complications (4/31, 12.9%) consisted fracture of the diaphysis (2/31, 6.5%), fracture of the greater trochanter (1/31, 3.2%), and sciatic nerve injury followed by a full recovery (1/29, 3.4%). The 8 (8/29, 27.5%) postoperative complications consisted of dislocation (2/29, 6.9%), stem subsidence (2/29, 6.9%), and non-union (4/29, 13.8%). Femoral implant survival at last follow-up was 87.1% (95% CI, 76.1-99.7). The mean HHS increased from 39.6±12.0 (range, 14-61) before surgery to 81.7±13.2 (range, 48-100) at last follow-up (p<0.01). The FJS at last follow-up indicated that the joint was forgotten in 14/29 (48.2%) cases and caused only acceptable symptoms in 9/29 (31.0%) of cases. Clinically significant (≥ 1cm) LLLI was present in 8/29 (27.6%) patients postoperatively compared to 19/29 (65.5%) preoperatively. The mean LLLI decreased from 20.8±19.7mm (range, 0-60mm) to 5.0±7.3mm (range, 0-30mm). Mean time to healing was 4.3±2.4 months (range, 2-11 months).

CONCLUSION

Regarding these complex procedures, this technique was associated with low rates of intraoperative fractures and early postoperative complications. However, femoral stem survival was shorter than in earlier studies and the non-union rate was high, despite satisfactory functional and clinical outcomes.

LEVEL OF EVIDENCE IV

A cross-sectional study evaluating patients' preferences for Salter innominate osteotomy

BACKGROUND

Residual acetabular dysplasia in children after reduction of hip dislocation is often treated using Salter innominate osteotomy to prevent future osteoarthritis. Preventive surgery for asymptomatic patients, which could result in overtreatment, should be carefully applied with consideration of patients' opinions. In this study, we aimed to describe opinions on Salter innominate osteotomy as preventive surgery for children among adult patients who had undergone periacetabular osteotomy for hip pain due to hip dysplasia.

METHODS

A mail-in questionnaire survey was conducted with 77 patients who underwent periacetabular osteotomy. Participants responded whether they would recommend Salter innominate osteotomy as preventive surgery for children and the reason for their opinion. We also performed a patient-based evaluation using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire and assessed clinical outcome measures with the Japanese Orthopedic Association score. Their recommendations and reasons were evaluated, and associations between their opinions and demographic and clinical characteristics were analyzed.

RESULTS

Forty-three patients (56%) responded to the questionnaire. Of these, 10 (23%) patients recommended undergoing Salter innominate osteotomy, 28 (65%) patients did not, and 5 (12%) patients responded they were undecided. No significant association was observed between their opinions and demographic/clinical characteristics evaluated in the survey. The most frequent reason for why they do not recommend Salter innominate osteotomy was related to uncertainty about future hip pain.

CONCLUSIONS

In total, 65% of the study participants did not recommend Salter innominate osteotomy for children with risk of dysplasia in the future. Participants' preferences regarding preventive surgery were not influenced by demographic and clinical characteristics.

A novel approach for screening standard anteroposterior pelvic radiographs in children

Anteroposterior pelvic radiography is the first-line imaging modality for diagnosing developmental dysplasia of the hip (DDH). Nonstandard radiographs with pelvic malposition make the correct diagnosis of DDH challenging. However, as the only method available for screening standard pelvic radiographs, traditional manual assessment is relatively laborious and potentially erroneous. We retrospectively collected 3,247 pelvic radiographs. There were 2,887 radiographs randomly selected to train and optimize the AI model. Then 362 radiographs were used to test the model's diagnostic performance. Its diagnostic accuracy was assessed using receiver operating characteristic (ROC) curves and measurement consistency using Bland-Altman plots. In 362 radiographs, the AI model's area under ROC curves, accuracy, sensitivity, and specificity for quality assessment was 0.993, 99.4% (360/362), 98.6% (138/140), and 100.0% (222/222), respectively. Compared with clinicians, the 95% limits of agreement (Bland-Altman analysis) for pelvic tilt index (PTI) and pelvic rotation index (PRI), as determined by the model, were -0.052-0.072 and -0.088-0.055, respectively.

CONCLUSIONS

The artificial intelligence-assisted method was more efficient and highly consistent with clinical experts. This method can be used for real-time validation of the quality of pelvic radiographs in current picture archiving and communications systems (PACS).

WHAT IS KNOWN

• Nonstandard pediatric radiographs with pelvic malposition make the correct diagnosis of developmental dysplasia of the hip (DDH) challenging. • Traditional manual assessment remains the only method available for screening standard pediatric pelvic radiographs, which is relatively laborious and potentially erroneous.

WHAT IS NEW

• This study proposed an artificial intelligence-assisted model to assess the quality of pediatric pelvic radiographs accurately and efficiently. • We recommend the integration of the model into current picture archiving and communications systems (PACS) for real-time screening of standard pediatric pelvic radiographs.

Patients with developmental dysplasia of the hip shows higher digit ratio (2D:4D)

BACKGROUND

Developmental dysplasia of the hip (DDH) encompasses a range of hip disorders, from dysplasia to dislocation. One key factor is sex, with women being four to eight times more susceptible to DDH than men. However, there have been no studies investigating the second-to-fourth digit ratio (2D:4D), a biomarker of prenatal sex steroid exposure, in DDH patients. This study aimed to explore whether there is an association between the 2D:4D ratio and DDH.

METHODS

Digital calipers were used to measure the second and fourth finger lengths of 250 patients treated for DDH and 200 patients in the healthy control group between January 2020 and January 2023. The Mann-Whitney U test was used for non-normally distributed variables and two-way analysis of variance to assess differences in measurements between DDH patients based on sex, side, and the interaction of sex and side. The intraclass correlation coefficient (ICC) was used to assess measurement repeatability.

RESULTS

The median (min-max) age was 10.00 (6-16) years in the DDH group, 12.00 (6-16) years in the control group, and 10 (6-16) years for the whole cohort. There was no significant difference in terms of age between the patient and control groups (p = 0.083). When comparing the DDH group with controls the former showed higher right 2D:4D and Δ2D:4D and these differences were significant in both males and females. Among the patients, controlling for side of dysplasia did not affect right 2D:4D, left 2D:4D or Δ2D:4D.

CONCLUSION

There was a significant association between higher 2D:4D ratios (both right and left hands) and DDH in both men and women. This indicates that the 2D:4D ratio, a marker of intrauterine estrogen/testosterone balance, is associated with DDH.

Screw fixation after tripe pelvic osteotomy is reliable: changes of acetabular correction are rare and do not correlate with risk factors

PURPOSE

The aim of this examination was to assess whether there is a change of acetabular correction after triple pelvic osteotomy (TPO) and if so, whether there is a correlation with patient-specific risk factors or with certain periods in the postoperative course.

METHODS

A consecutive series of 241 TPO was reviewed retrospectively. The close-meshed radiographic follow-up of the first 12 weeks comprised pelvic radiographs performed immediately after the procedure, 5 days, 6 and 12 weeks after TPO. Three observers measured the lateral center edge angle, acetabular index and the craniocaudal offset of the pubic osteotomy. Patient-specific risk factors (e. g. age, gender, body mass index, nicotine abuse) and certain periods in the postoperative course were correlated with a change of acetabular correction.

RESULTS

After application of the exclusion criteria, 225 hips were available for further examination. Intraclass correlation coefficient resulted in predominantly excellent agreement between the measurements of the three observers (0.74-0.91). In 27 cases (12%), the three observers agreed on a change of acetabular correction. In 18 cases (8%), there was a slight change, in 9 cases (4%), a relevant change. The latter entailed consequences in the postoperative aftercare. General equation estimation did not show any correlation between a change of acetabular correction and patient-specific risk factors or certain periods in the postoperative course (p = 0.79-0.99).

CONCLUSION

Every once treated hip should be followed-up with the same attention, irrespective of the apparent risk profile. There is no rationale to skip a radiographic follow-up in the first 12 weeks after TPO.

Prognostic factors for failed Pavlik harness treatment in infants with developmental dysplasia of the hip: a retrospective cohort study

PURPOSE

Pavlik harness treatment is the most common treatment in newborns diagnosed with developmental dysplasia of the hip (DDH). The success rates and predictors for failure have been debated over the last decade. In this study, we explored our treatment failure rate and potential prognostic factors that could predict the failure of Pavlik harness (PH) treatment in patients with DDH.

METHODS

Two hundred and sixty-five patients were treated with PH based on the Graf hip types of classification. Age, gender, first born status, family history, foot deformity, plagiocephaly, breech presentation, hip abduction, hip stability, Graf hip type, Galeazzi sign, bilateralism, and femoral nerve palsy were tested as predictors for failure in multivariate logistic regression mode. Success and failure were determined by the normalization of the hip based on the Graf hip classification.

RESULTS

The failure rate of patients treated with Pavlik harness was 16.6% which is within the reported range of failure rate. The mean age of patients who were successfully treated was 6.73 weeks in comparison to 8.84 weeks for those who failed. Age, plagiocephaly, hip instability, Graf classification, and the development of femoral nerve palsy were found to be predictors for failure of PH treatment upon univariate analysis only. However, only the presence of Galeazzi sign, hip instability, high grades of Graf hip classification, and the development of femoral nerve palsy proved to be independent predictors for failed PH treatment upon multivariate logistic regression analysis.

CONCLUSIONS

Pavlik harness treatment is a successful treatment with an average success of 83.4%. Several independent predictors for failure of PH treatment have been identified. These include a positive Galeazzi sign, a frankly dislocated hip, Graf types III and IV, and the development of femoral nerve palsy.

Natural progression of the pubofemoral distance with age and its correlation with future acetabular index

OBJECTIVES

This study investigated the progression of pubofemoral distance (PFD) with age and assessed the correlation between PFD and late acetabular index (AI) measurements.

METHODS

This prospective observational study was conducted between January 2017 and December 2021. We enrolled 223 newborns who underwent the first, second, and third hip ultrasounds, and pelvis radiograph at a mean age of 18.6 days, 3.1 months, 5.2 months, and 6.8 months, respectively. The difference between PFD measured at serial ultrasounds and the correlation with AI were analyzed.

RESULTS

The PFD increased significantly (p < 0.001) at serial measurements. The mean PFD at the first, second, and third ultrasounds were 3.3 (2.0-5.7), 4.3 (2.9-7.2), and 5.1 (3.3-8.0) mm, respectively. The PFD at three ultrasounds were all significantly (p < 0.001) and positively correlated with AI, with the Pearson correlation coefficients being 0.658, 0.696, and 0.753 for the first, second, and third ultrasounds, respectively. Using AI as reference, the diagnostic ability of PFD was calculated by the areas under the receiver operating characteristic curve, which was 0.845, 0.902, and 0.938 for the first, second, and third PFD, respectively. For the first, second, and third ultrasounds, PFD cutoff values of ≥ 3.9, ≥ 5.0, and ≥ 5.7 mm, respectively, yielded the greatest sensitivity and specificity in predicting late abnormal AI.

CONCLUSION

The PFD naturally progresses with age and is positively correlated with AI. The PFD has potential for predicting residual dysplasia. However, the cutoff for abnormal PFD values may require adjustment according to the patient's age.

KEY POINTS

• The pubofemoral distance measured in hip ultrasonography naturally increases as the infant's hips mature. • The early pubofemoral distance demonstrates a positive correlation with late acetabular index measurements. • The pubofemoral distance may help physicians predict abnormal acetabular index. However, the cutoff for abnormal pubofemoral distance values may require adjustment according to patient's age.

Identification of screw spacing on pediatric hip locking plate in proximal femoral osteotomy

This study describes a computational analysis technique for evaluating the effect of screw spacing and angle on the pediatric hip locking plate system in proximal femoral osteotomy in pediatric patients having DDH with an aberrant femoral head and femoral angle. Under static compressive load conditions, the stresses of the screw and bone were examined as the screw spacing and angle changed. The spacing and angle of various screws were specifically considered as variables in this study based on the pile mechanism studied in civil engineering. As with the group pile mechanism, the tighter the screw spacing under static compressive loads, the more the overlapping effect between the bone stresses and the screws develops, increasing the risk of injuring the patient's bone. Therefore, a series of simulations was performed to determine the optimal screw spacing and angles to minimize the overlapping effect of bone stress. In addition, a formula for determining the minimum screw spacing was proposed based on the computational simulation results. Finally, if the outcomes of this study are applied to pediatric patients with DDH in the pre-proximal femoral osteotomy stage, post-operative load-induced femur damage will be reduced.

Visualization of acetabular coverage with radar chart before and after curved periacetabular osteotomy in dysplastic hips

BACKGROUND

Curved periacetabular osteotomy (CPO) is indicated for patients with developmental dysplasia of hip (DDH) to prevent progressive osteoarthritis. Patients with DDH have not only lateral acetabulum dysplasia but also anterior and posterior dysplasia. The full circumference acetabular coverage angle (ACA) of the femoral head should be evaluated preoperatively. This study aimed to determine the full circumference ACA in the patients with DDH before and after CPO compared with the coverage in normal patients.

METHODS

Twenty-three patients (a total of 24 hips) with DDH undergoing CPO between February 2006 and March 2014 were included in this study. The normal group was defined as the normal side in patients with unilateral osteonecrosis of the femoral head (ONFH) and the non-collapsed femoral head side in patients with bilateral ONFH. Pre- and postoperative hip functions were evaluated using the Japanese Orthopedic Association (JOA) hip score. ACA was measured using pre- and postoperative three-dimensional computed tomography (3DCT) and described as a clock using a radar chart. The ACA of the normal group was evaluated in the same manner as that for patients who underwent CPO. The ACA before CPO was compared with the ACA after CPO, the ACA before CPO was compared with that of the normal group and the ACA after CPO was compared with that of the normal group at each location.

RESULTS

The mean JOA hip scores improved significantly from 69 preoperatively to 88 postoperatively. The superior, posterior, and anterior ACA after CPO significantly increased and the inferior ACA decreased compared with ACA before CPO. The superior, posterior, and anterior ACA before CPO were significantly smaller than ACA in the normal group. The ACA after CPO were similar to the normal group.

CONCLUSIONS

CPO improved the anterosuperior coverage of the femoral head but reduced its inferior coverage. The radar chart could visualize acetabulum full circumference and was useful for three-dimensional pre-postoperative evaluation.

The Role of Global Femoral Offset in Total Hip Arthroplasty with High Hip Center Technique

OBJECTIVE

The high hip center (HHC) technique has been proposed for the treatment of patients with developmental dysplaisa of the hip (DDH) who have an acetabular bone defect. However, the importance of global femoral offset (FO) in the application of this technique has not been sufficiently appreciated. Our goals were to confirm that the HHC technique is feasible in the treatment of patients with DDH and to assess the function of global FO in this procedure.

METHODS

We retrospectively analyzed 73 patients who underwent total hip arthroplasty using high hip center technique for unilateral DDH at our hospital between January 2014 and June 2019. According to global FO, the patients were split into three groups: increased FO group (increment greater than 5 mm), restored FO group (restoration within 5 mm) and decreased FO group (reduction greater than 5 mm). Patients' medical records and plain radiographs were reviewed. One-way ANOVA was used to compare radiographic outcomes and Harris hip score (HHS). Paired t-test was used to assess preoperative and postoperative HHS and leg length discrepancy. Trochanteric pain syndrome, Trendelenburg sign and postoperative limp was evaluated with Fisher's exact test.

RESULTS

The average follow-up time was 7.5 ± 1.4 years. The patients' HHS and leg length discrepancy were significantly improved (p < 0.05). In terms of vertical acetabular height, abductor arm, postoperative leg length difference, and acetabular cup inclination, there was no statistically significant difference between the three groups. At the last follow-up, HHS was significantly higher in the restored FO group than in the decreased FO and increased FO groups. Trochanteric pain syndrome occurred in 15.0% and Trendelenburg sign and postoperative limp in 8.2% of all patients, respectively. Trochanteric pain syndrome, Trendelenburg sign and postoperative limp did not differ significantly across the three groups. One patient in increased FO group underwent revision for dislocation 6 years after surgery.

CONCLUSION

The HHC technique is an alternative technique for total hip arthroplasty in patients with acetabular bone abnormalities, according to the results of the mid-term follow-up. Also, controlling the correction of the global femoral offset to within 5 mm may lead to better clinical outcomes.

Chondro-osseous border in baby hip ultrasonography for developmental dysplasia of the hip: an indispensable litmus paper for the accuracy of scientific publications

PURPOSE

The aim of our study was to use the chondro-osseous border (COB) as an indispensable assessment criterion to evaluate the quality of baby hip ultrasonography (US) images in the literature pertaining to the application of Graf's technique.

MATERIALS AND METHODS

Our literature review search yielded 144 articles. Of these, 41 contained images that were stated to be based on the application of Graf's technique. Two reviewers, a radiologist and an orthopaedic surgeon, both course instructors for the use of baby hip US for developmental dysplasia of the hip (DDH), independently evaluated the articles to assess the diagnostic validity of the published images on the basis of a single criterion: the identification of the COB.

RESULTS

Of the 41 articles which were analyzed, 15 contained images without a COB, which corresponds to 36% (roughly, one out of three). Articles from countries where universal screening is performed (Germany, Italy, Switzerland, Mongolia) were all correct. All the articles from Turkey, a country which has made significant contribution with published material about Graf's technique over many years, and most of the articles from China (80%), where Graf's technique has become popular in recent years, contained correct images.

CONCLUSION

Published literature lacks strict criteria for the publication of correct images corresponding to Graf's technique in baby hip US. This fact raises concerns about the quality of published material (and, as a corollary, the quality of clinical application of the technique) and should have ramifications on scientific journal policies regarding the publication of such manuscripts.

Are the outcomes of single-stage open reduction and Dega osteotomy the same when treating DDH in patients younger than 8 years old? A prospective cohort study

BACKGROUND

The primary objective was to report our early results after a one-stage procedure [open reduction (OR), Dega pelvic osteotomy (DPO), and femoral osteotomy (FO) when needed] for surgical management of a cohort of patients with developmental dysplasia of the hip (DDH). The secondary objective was to compare the functional, radiological, and complications among patients younger and older than 30 months.

MATERIALS AND METHODS

This prospective cohort study included 71 hips with DDH in 61 patients with a mean age of 34.3 ± 19.5 months. All patients underwent one-stage surgical procedures, including OR + DPO and FO, if needed. Functional and radiographic assessment at the last follow-up was conducted using the modified Severin grading system and the Severin classification system, respectively, in addition to assessing the acetabular index (AI), osteotomies healing, and presence of complications. We divided patients into two groups, younger than 30 months (group I) and older than 30 months (group II).

RESULTS

We included 35 hips in group I and 36 in group II. All hips received OR + DPO, while 25 (69.4%) hips in group II had FO. The operative time was significantly longer in group II (103.19 ± 20.74 versus 72.43 ± 11.59 min, p < 0.001). After a mean follow up of 21.3 ± 2.3 months, the functional outcomes were satisfactory in 62 (87.3%) hips (94.3% in group I and 80.6% in group II, p = 0.35). There was a significant improvement in the AI in all patients compared with preoperative values (27.2° ± 2.9 versus 37° ± 4.2, p < 0.05). Furthermore, 63 (88.7%) hips had satisfactory radiographic outcomes (94.3% in group I and 83.3% in group II, p = 0.26), and all osteotomies showed radiographic healing. The overall complications incidence was significantly lower in group I compared with group II (5.7% versus 30.6%, p < 0.05), and avascular necrosis occurred in 4 (5.6%) hips, all in group II (p = 0.06).

CONCLUSION

One-stage procedure entailing open reduction, Dega pelvic osteotomy, and femoral osteotomy when needed for managing DDH in patients younger than eight years old revealed acceptable clinical and radiological outcomes. However, there was a higher need for a concomitant femoral osteotomy in patients older than 2.5 years, and complications were more frequent.

LEVEL OF EVIDENCE III

Relationships between self-perceived and clinical expression of pain and function differ based on the underlying pathology of the human hip

BACKGROUND

Patient-reported outcomes are commonly used to assess patient symptoms. The effect of specific hip pathology on relationships between perceived and objectively measured symptoms remains unclear. The purpose of this study was to evaluate differences of function and pain in patients with FAIS and DDH, to assess the correlation between perceived and objective function, and to determine the influence of pain on measures of function.

METHODS

This prospective cross-sectional study included 35 pre-operative patients (60% female) with femoroacetabular impingement syndrome (FAIS) and 37 pre-operative patients (92% female) with developmental dysplasia of the hip (DDH). Objectively measured function (6-min walk [6MWT], single leg hop [SLHT], Biodex sway [BST], hip abduction strength [HABST], and STAR excursion balance reach [STAR] tests), patient-reported function (UCLA Activity, Hip Outcome Score [HOS], Short Form 12 [SF-12], and Hip Disability and Osteoarthritis Outcome Score [HOOS]), and patient-reported pain (HOOS Pain, visual analogue scale (VAS), and a pain location scale) were collected during a pre-surgical clinic visit. Between-group comparisons of patient scores were performed using Wilcoxon Rank-Sum tests. Within-group correlations were analyzed using Spearman's rank correlation coefficients. Statistical correlation strength was defined as low (r =  ± 0.1-0.3), moderate (r =  ± 0.3-0.5) and strong (r >  ± 0.5).

RESULTS

Patients with DDH reported greater pain and lower function compared to patients with FAIS. 6MWT distance was moderately-to-strongly correlated with a number of patient-reported measures of function (FAIS: r = 0.37 to 0.62, DDH: r = 0.36 to 0.55). Additionally, in patients with DDH, SLHT distance was well correlated with patient reported function (r = 0.37 to 0.60). Correlations between patient-reported pain and objectively measured function were sparse in both patient groups. In patients with FAIS, only 6MWT distance and HOOS Pain (r = -0.53) were significantly correlated. In patients with DDH, 6MWT distance was significantly correlated with VAS Average (r = -0.52) and Best (r = -0.53) pain.

CONCLUSION

Pain is greater and function is lower in patients with DDH compared to patients with FAIS. Moreover, the relationship between pain and function differs between patient groups. Understanding these differences is valuable for informing treatment decisions. We recommend these insights be incorporated within the clinical continuum of care, particularly during evaluation and selection of surgical and therapeutic interventions.

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.

Risk factors for lateralization or superiorization of the center of the femoral head in eccentric rotational acetabular osteotomy

PURPOSE

This study aimed to clarify the factors that cause the lateralization and superiorization of the femoral head after eccentric rotational acetabular osteotomy (ERAO) by examining the three-dimensional morphology of the osteotomy site using computed tomography (CT).

METHODS

This study included 52 patients who underwent ERAO for hip dysplasia. Postoperatively, the center of the femoral head was measured for lateralization and superiorization. We defined the iliac and sciatic osteotomy angles in the coronal and axial CT planes, respectively. The surgical factors for lateralization and superiorization were analysed using multiple logistic regression analysis. We also analysed the relationship between the femoral head relocation and clinical outcomes (as assessed using Japanese Orthopaedic Association (JOA) scores).

RESULTS

Thirty-five patients had hips with lateralized femoral heads, and 25 patients' femoral heads were superiorized. Logistic regression analysis revealed that a higher osteotomy angle of the ilium in the coronal plane served as a significant predictor of superiorization of the femoral head. Similarly, a larger osteotomy angle of the ischium in the axial plane and the amount of change in the lateral centre edge angle were identified as predictors of lateralization. A weak negative correlation was observed between the amount of lateralization and the JOA score.

CONCLUSION

Large osteotomy angles in the superior and posterior aspects of the acetabulum carry a risk of superiorization and lateralization of the center of the femoral head. Surgeons should be aware of the need to chisel through the internal plate to achieve the results described in the ERAO theory.

STUDY DESIGN

A single-center, retrospective study.

Three-dimensional femur morphology analysis for the optimal location of subtrochanteric osteotomy with an implanted Wagner cone stem in total hip arthroplasty for Crowe type IV developmental dysplasia of the hip

BACKGROUND

This study aimed to accurately evaluate the matching of proximal and distal femoral segments and fitting of the femur-femoral stem in patients with Crowe type IV developmental dysplasia of the hip (DDH) who have undergone subtrochanteric osteotomy at different locations with an implanted Wagner cone stem to improve the rate of the bone union at the osteotomy site.

METHODS

Three-dimensional femur morphology of 40 patients with Crowe type IV DDH was evaluated at each cross-section to determine the femoral cortical bone area. This study focused on five osteotomy lengths (2.5, 3, 3.5, 4, and 4.5 cm). The overlapped area between the proximal and distal cortical bone segments was defined as the contact area (S, mm²), and the contact area to distal cortical bone area ratio was defined as the coincidence rate (R). Three indicators were used to evaluate the matching and fitting of the osteotomy sites with the implanted Wagner cone stems: (1) higher S and R between the proximal and distal segments; (2) the effective fixation length of the femoral stem at the distal segments being at least 1.5 cm; and (3) osteotomy did not involve the isthmus.

RESULTS

In all groups, S significantly decreased in the two proximal levels above the 0.5 cm level below the lesser trochanter (LT) compared with those below this level. In comparison, at osteotomy lengths from 2.5 to 4 cm, R significantly decreased in the three proximal levels. The optimal osteotomy levels ranged from 1.5 and 2.5 cm below the LT for an appropriately sized stem.

CONCLUSIONS

Subtrochanteric osteotomy at the optimal level not only ensures fitting of the femur-femoral stem but also meets the requirements of a higher S and R to ensure adequate reduction and stabilization at the osteotomy site, which may contribute to the bone union. Although the optimal osteotomy level varies with the size of the femoral stem and the length of the subtrochanteric osteotomy, the optimal osteotomy levels for an appropriately sized Wagner cone femoral stem implantation range from 1.5 to 2.5 cm below the LT.

Ultrasonography in the evaluation of various factors of developmental dysplasia of the hip in infants: Results from a retrospective study in a large hospital of northwest China

BACKGROUND

The occurrence and development of developmental dysplasia of the hip (DDH) are related to a variety of factors, which have been reported in the literature, but the literature does not mention factors related to the severity of DDH. The purpose of this study is to analyze the related factors of the occurrence and severity of DDH in combination with the Graf ultrasonic diagnostic classification.

METHODS

This study was a monocentric retrospective study describing the factors associated with DDH in a large hospital of northwest China. A total of 3046 infants (6092 hips) within 6 months after birth using the Graf method were admitted to our department between 2014 and 2018. We analyzed data of DDH. After reviewing medical charts and diagnostic examination results, we assessed whether factors such as ethnicity, gender, gestational age, birth weight, diagnosis age, maternal age, mode of delivery, fetal presentation, amniotic fluid volume and birth order, had any effect on development of hip.

RESULT

① Analysis showed that DDH mostly occurs in female and left hip joint, related to intrauterine fetal presentation, amniotic fluid volume, gestational age, mode of delivery, prenatal weight, and diagnosis age after birth, and the occurrence of DDH is also related to maternal age (All P＜0.05). Ethnicity and first born showed have no obvious correlation with DDH incidence (p = 0.718, 0.147, respectively). ② The strongest correlation was found with amniotic fluid, followed by birth weight. ③ The severity of DDH was correlated with ethnicity, births, prenatal weight, gestational age, diagnosis age and maternal age (All P＜0.05, respectively). ④ There were significant differences in treatment methods, duration and prognosis among different types of DDH.

CONCLUSIONS

The occurrence and development of DDH are related to a variety of factors. Ultrasound examination can provide an early assessment of the hip development status of infants and may play an important role in establishing an early clinical diagnosis treatment and monitoring and prognosis.