Globally inconsistent: Countries with top health indices erratic developmental hip dysplasia screening protocols.

Purpose: Developmental hip dysplasia is a prevalent pediatric musculoskeletal condition that lacks international standardized screening. We sought to characterize developmental hip dysplasia screening practices in countries with the top global health indices. We also explored diverse definitions in reported epidemiologic rates of this condition. Methods: We performed a scoping review of developmental hip dysplasia screening protocols utilizing countries ranked in the top 25 of the Bloomberg Global Health Index using a protocolized search strategy, progressing from academic to layperson sources. A reference was eligible for inclusion if it mentioned the countries' screening program and developmental hip dysplasia was the pathology of concern. Incidence rates, when present, were also recorded. The United States Census Bureau's International Database tool provided countries' populations. We compiled the data and performed descriptive statistics and appropriate validation methods. Results: Twenty countries (80%) had searchable screening programs. Clinical screening with selective universal screening was the most commonly observed (n = 16). Four countries had universal ultrasound screening: Switzerland, Austria, Germany, and Slovenia. Five countries did not have searchable programs. No countries employed radiographic screening. Incidence rates were expressly stated in the literature for nine countries; however, the cohort of interest varied from developmental hip dysplasia versus severity of developmental hip dysplasia versus miscellaneous (e.g. requiring hospitalization). Conclusion: The findings of this investigation highlight international inconsistencies regarding developmental hip dysplasia screening and epidemiologic data. Screening variations exist despite consensus statements calling for uniformity. We agree with prior literature advocating for increasing consistency in developmental hip dysplasia management or, at a minimum, increasing transparency regarding how we manage these young patients.

Protective effect of modified lange "second position" for developing avascular necrosis following closed reduction for developmental dysplasia of the hip.

BACKGROUND: Developmental Dysplasia of the Hip (DDH) is a condition affecting hip joint development in children, presenting multiple manifestations. Immobilization methods to ensure hip concentricity, such as the human position and modified Lange position, vary in effectiveness and risks, especially avascular necrosis. The purpose of this study was to identify whether closed reduction (CR), with two different immobilization techniques, is effective in avoiding complications such as residual hip dysplasia (RHD), re-dislocation, and Avascular Necrosis (AVN). METHODS: A total of 66 patients with DDH (84 hips) were treated with two different techniques of immobilization (groups A and B); the mean age at the time of reduction was 8 (6-13) months. The rates of RHD, Re-dislocation, and AVN were determined with a minimum follow-up of 48 months in both techniques. RESULTS: The Chi-square analysis conducted across the study groups unveiled that patients in Group B demonstrated a protective effect against AVN compared to those in Group A (OR: 0.248, 95% CI: 0.072-0.847, p = 0.026). However, no statistically significant differences were found between the groups concerning RHD (p = 0.563) and re-dislocation (p = 0.909). CONCLUSIONS: After the initial Human Position immobilization, the second cast with the modified Lange "second position" demonstrated a protective effect compared with maintaining the Human Position immobilization throughout the immobilization period, reducing the likelihood of AVN development in patients undergoing closed reduction for developmental dysplasia of the hip.

Hip Dysplasia in a Context of Blue Rubber Bleb Nevus Syndrome, 5-years Follow-up after Hip Arthroplasty.

Introduction: Blue rubber bleb nevus syndrome (BRBNS) is a rare congenital vascular disorder that affects the venous system. Lesions are multiple and involved not only the skin and subcutaneous tissue but also muscles, joints and organs such as the gastrointestinal tract. At present, little is known regarding its potential orthopedic complications. Case Report: We present a unique case of a patient with BRBNS displaying both intra-articular and extra-articular severe venous malformation (VM) of the hip. This extensive VM caused severe deformities in bone growth, mainly affecting the proximal femur, and impacted the muscular development of the gluteus medius and gluteus maximus. Its intra-articular extension, along with repeated secondary hemarthrosis, led to cartilaginous destruction. Consequently, the patient presented with significant coxa valga and developed acetabular dysplasia and subluxation of femoral head, during growth. In order to restore hip function and alleviate pain, the patient underwent a total hip arthroplasty (THA) at the age of 18. Discussion: The dysplastic changes in the hip joint observed in this case are attributed to the deleterious effects of VMs and coxa valga on joint anatomy and biomechanics. VMs induce recurrent hemarthrosis, leading to cartilage destruction and hip instability. Additionally, coxa valga alters hip biomechanics, exacerbating joint instability and accelerating wear. Surgical intervention with THA aimed to restore joint stability and function, although challenges arose due to anatomical complexities and limited prosthetic options. Conclusion: This is the first reported case of hip dysplasia associated with BRBNS. This case shows the involvement of vascular malformation in the development of hip dysplasia leading to total hip arthroplasty. The surgical planning and technique must take the specificity of this pathology into account to get the best result possible for the patient. This case illustrates the importance of a multidisciplinary approach to treat patients with this specific syndrome and adds valuable information to the limited literature on orthopedic complications in BRBNS.

Rehabilitation-Specific Predictors of Pain Intensity and Physical Activity Levels in Individuals With Acetabular Dysplasia 6 Months After Periacetabular Osteotomy.

INTRODUCTION: Individuals with acetabular dysplasia often report hip joint instability, pain, and poor hip-related function. Periacetabular osteotomy (PAO) is a surgical procedure that aims to reposition the acetabulum to improve joint congruency and improve pain and function. We aimed to examine the influence of presurgery clinical measures on functional recovery following PAO and the associations among clinical outcomes after PAO. METHODS: We screened 49 potential participants, 28 were enrolled, and 23 completed both study visits (pre-PAO and 6 months post-PAO). We evaluated dynamometer-measured hip and thigh strength, loading patterns during a squat and countermovement jump (CMJ), pain intensity, and device-measured physical activity (PA) levels (light, moderate-to-vigorous PA [MVPA], and daily steps). We used linear regression models to examine the influence of muscle strength (peak torque; limb symmetry index [LSI]) and loading patterns before PAO on pain intensity and PA levels in individuals 6 months following PAO. Additionally, we used Pearson correlation coefficient to examine cross-sectional associations among all variables 6 months following PAO. RESULTS: Lower extremity muscle strength and loading patterns during the squat and CMJ before PAO did not predict pain intensity or device-measured PA levels in individuals 6 months following PAO (p > 0.05). Six months following PAO, higher knee extensor LSI was associated with higher time spent in MVPA (r = 0.56; p = 0.016), higher hip abductor LSI was associated with both lower pain (r = 0.50; p = 0.036) and higher involved limb loading during the squat task (r = 0.59; p = 0.010). Lastly, higher hip flexor LSI was associated with higher CMJ takeoff involved limb loading (r = 0.52; p = 0.021) and higher involved hip extensor strength was associated with higher CMJ landing involved limb loading (r = 0.56; p = 0.012). CONCLUSION: Six months after PAO, higher hip and thigh muscle strength and strength symmetry were associated with lower pain, higher PA levels, and greater normalized limb loading during dynamic movement tasks.

Can acetabular dysplasia be measured on axial CT? A measurement for trauma surgeons.

BACKGROUND: Acetabular dysplasia has been theorized as a risk factor instability amongst common acetabular fractures, such as posterior wall (PW) fractures. However, common radiographic measurements often cannot be acquired in trauma patients. We evaluated axial computed tomography (CT) scans to identify novel, easily-obtained measurements that correlate with acetabular dysplasia for use in surgical indications and planning. METHODS: Patients with known acetabular dysplasia undergoing elective periacetabular osteotomy were selected. A different group of patients without pelvic ring or acetabular fractures from an institutional trauma registry were selected as a comparison group. Standard indices of dysplasia were collected, such as center-edge angle (CEA). Acetabular geometric measurements were taken at three axial levels: 0 - cranial CT slice at the dome; 1 - cranial CT where the dome is an incomplete circle; 2 - cranial CT with femoral head visible. Distances between levels were also calculated: Levels 0-1 (Dome Height; DH), Levels 1-2 (Head Height; HH), and Dome-Head Difference (DH - HH = DHD). RESULTS: DH, HH, and DHD were all significantly correlated with CEA, Tonnis angle, and Sharp's angle in dysplastic hips. All dysplastic hips had DH ≤ 2.5 mm and HH ≥ 1.25 mm. DHD ≤ 0 mm was most specific (93.6 % sensitive, 77.3 % specific) for predicting dysplasia. CONCLUSION: DH ≤ 2.5 mm, HH ≥ 1.25 mm, and DHD ≤ 0 mm were independently associated with dysplasia on axial CT scans. These measurements may be quickly and easily used by trauma surgeons to assess a trauma-based axial CT scan for acetabular dysplasia.

Total Hip Replacement and Femoral Nail Lengthening for Hip Dysplasia and Limb Length Discrepancy: A Literature Review.

Developmental dysplasia of the hip (DDH) is a serious condition resulting in inadequate acetabular development, distorted bone configuration, and substantially altered hip biomechanics. An extensive leg length discrepancy (LLD) is commonly encountered in such cases, making a total hip arthroplasty (THA) procedure extremely challenging. Although good results in terms of patients' satisfaction, implant survival rates and overall improved quality of life have been reported, complication rates are considerably higher than primary THA procedures performed for idiopathic osteoarthritis. Reconstructing a dysplastic hip arthrosis and equalizing a preexisting LLD is a technically demanding procedure that is associated with significant bone and soft tissue complications. Intramedullary lengthening through motorized nails has become increasingly popular to address difficult cases with extensive LLD following THA in recent years. However, limited data on femoral lengthening procedures implemented following THA are available considering complications, radiological results, and patient-reported outcomes following staged THA and subsequent femoral lengthening using a femoral magnetically-driven intramedullary lengthening nail. We performed a literature review of the past 10 years in PubMed using the terms neglected hip dislocation, DDH, THA, and intramedullary lengthening nail as keywords. A total amount of eight cases addressing LLD through a telescoping intramedullary nail following THA in DDH have been reported in recent literature. All eight patients underwent primary THA for DDH followed by the implantation of the intramedullary lengthening nail. The mean THA was lengthened by 28.9 mm (from 13.0 to 45.0). The mean time for nail implantation after THA was 11.1 months (from 3.5 to 21). The mean time for lengthening per day through the nail was 0.94 mm (from 0.65 to 1.0) from 26 days to 70 days, and the mean lengthening through the nail was 37.6 mm (from 24.0 to 70.0). Good union and consolidation rates were reported by the authors, while there were no complications. The intramedullary distraction osteogenesis method with a telescopic rod can be an effective method to manage leg length discrepancies while avoiding soft tissue complications in challenging cases of DDH.

Development of an aid to detect adults acetabular hip dysplasia (the ALPHA alert): A mixed methods study.

OBJECTIVES: To identify the signs and symptoms that people living with acetabular hip dysplasia (AHD) describe and to provide an aid for translating the findings into practice. METHODS: A three-phased mixed methods study. Phase 1 employed an open-question online survey that enabled people with AHD (aged ≥16 years) to describe features associated with their condition. Responses were thematically analysed. A Phase 2 survey used these themes to establish how common those features were. Phase 3 created a mnemonic that prompts clinicians to suspect AHD. RESULTS: Ninety-eight respondents completed Phase 1 and sixty-two completed Phase 2. From the responses, five themes were identified: Demographic and Diagnostic Profile; Characteristics of Posture and Gait; Pain; Childhood Hip and Family History; and Hip Joint Characteristics. Within these themes, 19 common signs and symptoms were reported, represented by the ALPHA mnemonic. ALPHA describes a young age at onset of problems (Age), a limp (Limp), progressing pain (Pain), a history of childhood and family hip anomalies (History) as well as hip joint hypermobility and instability (Articulation). CONCLUSION: The findings extend current understanding of AHD indicators. ALPHA alerts clinicians to suspect a diagnosis of AHD. ALPHA may facilitate timelier referral of patients for diagnostic X-Ray and appropriate treatment. Future studies should evaluate its clinical utility.

ECAD study: Evaluating agreement degree among paediatricians in hip dysplasia assessment by the Graf ultrasound method.

Developmental dysplasia of the hip (DDH) is the most common musculoskeletal anomaly of childhood. This study analyses paediatrician's concordance performing hip ultrasound according to Graf's method. An analytical cross-sectional study is designed. Patients' hips are evaluated by Graf's ultrasound method at 4-6 and 12-16 weeks of age. Demographic characteristics, pregnancy history, factors related to DDH, hip type, and α and ß angles are collected. To assess the agreement degree of hip diagnosis and hip types Kappa index (I. kappa) is used. Intraclass correlation coefficient (ICC) evaluates the concordance of α and ß angles. A p value < 0.05 is considered statistically significant. All results are represented with their 95% confidence interval (95% CI). Four hundred sixty-seven neonates are recruited and meet the inclusion criteria. A total of 3182 images were analysed. Agreement between paediatricians according to hip diagnosis and different types ranges from moderate to almost perfect I. kappa 0.6-1.0 (95% CI 0.5-0.7; 95% CI 1.0-1.0). α angle ICC for paediatricians is between 0.75 and 0.88 (95% CI 0.61-0.86; 95% CI 0.80-0.92). ß angle value agreement degree among paediatricians at both visits is moderate. The Graf method is the most popular ultrasound technique for hip assessment. In our setting, paediatricians carry out children follow-up; therefore, they should perform universal screening. In this study agreement degree between paediatricians varies between substantial and almost perfect. Conclusion: The Graf ultrasound procedure performed by paediatricians is a reliable test and can be used for DDH screening. What is Known • Developmental dysplasia of the hip (DDH) is the most common congenital musculoskeletal anomaly of childhood. Early diagnosis and treatment improve DDH prognosis. Lack of detection can cause complications such as lameness, early osteoarthritis and need for hip replacement at an early age. What is New • Today, the best screening method is still subject of debate. But it seems that with selective screening many pathological hips go unnoticed. Universal screening implementation may be a challenge in some countries. But the question is if this could be carried out by paediatricians as part of healthy child follow-up.

Developmental Dysplasia of the Hip and Laterality: The Importance of Graded Severity of the Contralateral Hip.

Background: Laterality and bilaterality have been reported as prognostic variables in developmental dysplasia of the hip (DDH) outcomes. However, there is little clarity across the literature on the reporting of laterality in developmental dysplasia of the hip (DDH) due to the variability in severity of the condition. It is widely accepted that the left hip is most frequently affected; however, the true incidence of unilateral left, unilateral right and bilateral cases can be hard to quantify and compare across studies. The purpose of this study was to examine laterality accounting for graded severity in a multi-centre, international prospective observational study of infants with hip dysplasia to demonstrate the complexity of this issue. Methods: A multi-centre, prospective hip dysplasia database was analyzed from 2010 to April 2015. Baseline diagnosis was used to classify patients into a graded laterality category accounting for hip status within the DDH spectrum. Results: A total of 496 patients were included in the analysis; 328 were <6 months old at diagnosis and 168 were between 6 and 18 months old. Of these patients, 421 had at least one frankly dislocated hip. Unilateral left hip dislocations were most common, with 223 patients, followed by unilateral right and bilateral dislocations with 106 and 92 respectively. Stratifying these patients based on status of the contralateral hip, 54 unilateral left and 31 unilateral right dislocated patients also had a dysplastic or unstable contralateral hip. There were significantly fewer bilateral patients in the 6 to 18-month group (p = 0.0005). When classifying laterality by affected hip, bilaterality became the predominant finding, comprising 42% of all patients. Conclusions: Findings from this multi-centre prospective study demonstrate the necessity to account for the graded severity in hip status when reporting DDH laterality. To accurately compare laterality across studies, a standardized, comprehensive classification should be established, as contralateral hip status may impact prognosis and treatment outcomes. Level of Evidence: Level II Prognostic Study.

Femoral head decentration on hip MRI: comparison between imaging planes, methods of contrast administration, and hip deformities.

OBJECTIVES: To compare the prevalence of femoral head decentration (FHD) on different MR imaging planes in patients undergoing direct/indirect hip MR arthrography (MRA) with asymptomatic controls and to evaluate its association with osseous deformities. METHODS: IRB-approved retrospective single-center study of symptomatic hips undergoing direct or indirect hip MRA at 3 T. Asymptomatic participants underwent non-contrast hip MRI at 3 T. FHD was defined as a continuous fluid layer between the acetabulum and femoral head and assessed on axial, sagittal and radial images. The association of intra-articular/intra-venous contrast agents and the prevalence of FHD was evaluated. The association of FHD with osseous deformities and joint damage was assessed using multiple logistic regression analysis. RESULTS: Three-hundred ninety-four patients (447 hips, mean age 31 ± 9 years, 247 females) were included and compared to 43 asymptomatic controls (43 hips, mean age 31 ± 6 years, 26 females). FHD was most prevalent on radial images and more frequent in symptomatic hips (30% versus 2%, p < 0.001). FHD prevalence was not associated with the presence/absence of intra-articular contrast agents (30% versus 22%, OR = 1.5 (95% CI 0.9-2.5), p = 0.125). FHD was associated with hip dysplasia (OR = 6.1 (3.3-11.1), p < 0.001), excessive femoral torsion (OR = 3.0 (1.3-6.8), p = 0.010), and severe cartilage damage (OR = 3.6 (2.0-6.7), p < 0.001). CONCLUSION: While rare in asymptomatic patients, femoral head decentration in symptomatic patients is associated with osseous deformities predisposing to hip instability, as well as with extensive cartilage damage. CRITICAL RELEVANCE STATEMENT: Decentration of the femoral head on radial MRA may be interpreted as a sign of hip instability in symptomatic hips without extensive cartilage defects. Its presence could unmask hip instability and yield promise in surgical decision-making. KEY POINTS: The best method of identifying femoral head decentration is radial MRI. The presence/absence of intra-articular contrast is not associated with femoral head decentration. Femoral head decentration is associated with hip deformities predisposing to hip instability.

Radiographic Findings Associated With Mild Hip Dysplasia in 3869 Patients Using a Deep Learning Measurement Tool.

Background: Hip dysplasia is considered one of the leading etiologies contributing to hip degeneration and the eventual need for total hip arthroplasty (THA). We validated a deep learning (DL) algorithm to measure angles relevant to hip dysplasia and applied this algorithm to determine the prevalence of dysplasia in a large population based on incremental radiographic cutoffs. Methods: Patients from the Osteoarthritis Initiative with anteroposterior pelvis radiographs and without previous THAs were included. A DL algorithm automated 3 angles associated with hip dysplasia: modified lateral center-edge angle (LCEA), Tönnis angle, and modified Sharp angle. The algorithm was validated against manual measurements, and all angles were measured in a cohort of 3869 patients (61.2 ± 9.2 years, 57.1% female). The percentile distributions and prevalence of dysplastic hips were analyzed using each angle. Results: The algorithm had no significant difference (P > .05) in measurements (paired difference: 0.3°-0.7°) against readers and had excellent agreement for dysplasia classification (kappa = 0.78-0.88). In 140 minutes, 23,214 measurements were automated for 3869 patients. LCEA and Sharp angles were higher and the Tönnis angle was lower (P < .01) in females. The dysplastic hip prevalence varied from 2.5% to 20% utilizing the following cutoffs: 17.3°-25.5° (LCEA), 9.4°-15.6° (Tönnis), and 41.3°-45.9° (Sharp). Conclusions: A DL algorithm was developed to measure and classify hips with mild hip dysplasia. The reported prevalence of dysplasia in a large patient cohort was dependent on both the measurement and threshold, with 12.4% of patients having dysplasia radiographic indices indicative of higher THA risk.

The Etiology of Neuromuscular Hip Dysplasia and Implications for Management: A Narrative Review.

This study summarizes the current knowledge of the etiology of hip dysplasia in children with neuromuscular disease and the implications for management. This article is based on a review of development of the hip joint from embryology through childhood growth. This knowledge is then applied to selective case reviews to show how the understanding of these developmental principles can be used to plan specific treatments. The development of the hip joint is controlled by genetic shape determination, but the final adult shape is heavily dependent on the mechanical environment experienced by the hip joint during growth and development. Children with neuromuscular conditions show a high incidence of coxa valga, hip dysplasia, and subluxation. The etiology of hip pathology is influenced by factors including functional status, muscular tone, motor control, child's age, and muscle strength. These factors in combination influence the development of high neck-shaft angle and acetabular dysplasia in many children. The hip joint reaction force (HJRF) direction and magnitude determine the location of the femoral head in the acetabulum, the acetabular development, and the shape of the femoral neck. The full range of motion is required to develop a round femoral head. Persistent abnormal direction and/or magnitude of HJRF related to the muscular tone can lead to a deformed femoral head and a dysplastic acetabulum. Predominating thigh position is the primary cause defining the direction of the HJRF, leading to subluxation in nonambulatory children. The magnitude and direction of the HJRF determine the acetabular shape. The age of the child when these pathomechanics occur acts as a factor increasing the risk of hip subluxation. Understanding the risk factors leading to hip pathology can help to define principles for the management of neurologic hip impairment. The type of neurologic impairment as defined by functional severity assessed by Gross Motor Function Classification System and muscle tone can help to predict the risk of hip joint deformity. A good understanding of the biomechanical mechanisms can be valuable for treatment planning.

Post-Arthroplasty Spatiotemporal Gait Parameters in Patients with Hip Osteoarthritis or Developmental Dysplasia of the Hip: An Observational Study.

Total hip arthroplasty (THA) is a preferred treatment for primary osteoarthritis (OA) or secondary degenerative arthropathy due to developmental hip dysplasia (DDH). Gait analysis is considered a gold standard for evaluating post-arthroplasty walking patterns. This study compared post-THA spatiotemporal gait parameters (SGPs) between OA and DDH patients and explored correlations with demographic and clinical variables. Thirty patients (15 per group) were recorded during gait and their SGPs were analyzed. Functionality was evaluated with the Oxford Hip Score (OHS). The OA patients were significantly older than DDH patients (p < 0.005). Significant and moderate to strong were the correlations between SGPs, age, and four items of the OHS concerning hip pain and activities of daily life (0.31 < Pearson's r < 0.51 all p < 0.05). Following THA, both groups exhibited similar levels of the examined gait parameters. Post-arthroplasty SGPs and OHS correlations indicate limitations in certain activities. Given the absence of pre-operative data and the correlation between age and SGPs and OHS, ANCOVA testing revealed that age adjusts OHS and SGP values, while pre-operative diagnosis has no main effect. These findings indicate that hip OA or DDH do not affect postoperative SGPs and patients' functionality. Future studies should examine both kinematic and kinetic data to better evaluate the post-THA gait patterns of OA and DDH patients.

Persistently elevated joint contact stress after periacetabular osteotomy is associated with joint failure at minimum 10-year follow-up.

Periacetabular osteotomy (PAO) is a common treatment for prearthritic hip dysplasia. The goal of this investigation was to determine if computationally assessed hip contact mechanics are associated with joint failure at minimum 10-year follow-up. One hundred patients with hip dysplasia (125 hips) completed patient-reported outcomes an average of 13.8 years (range 10.0-18.0 years) after PAO. 63/125 hips were classified as having failed: 26 converted to total hip arthroplasty (THA) and 37 with significant disability indicated by modified Harris Hip Score (mHHS) ≤ 70. Differences in discrete element analysis-computed contact mechanics were compared between (1) preserved and failed hips, (2) preserved hips and hips that failed by THA, and (3) preserved hips and hips that failed by mHHS ≤ 70. Failed hips had significantly higher preoperative contact stress and exposure metrics (p < 0.001-0.009) than preserved hips. Failed hips also had significantly higher postoperative peak contact stress (p = 0.018), higher mean contact stress (p < 0.001), and smaller contact area (p = 0.044). When assessed based on type of failure, hips that failed by THA had significantly higher postoperative contact stress and exposure metrics than preserved hips (p < 0.001-0.020). In hips that failed by mHHS ≤ 70, mean postoperative contact stress exposure was significantly higher compared to preserved hips (p = 0.043). Despite improved radiographic measures of dysplasia after PAO, pathologic joint contact mechanics can persist and predict treatment failure at minimum 10 years after surgery. Operative and nonoperative techniques specifically intended to reduce harmful contact mechanics in dysplastic hips may have the potential to further improve clinical outcomes after PAO.

The role of different acetabular morphologies on patient-reported outcomes following periacetabular osteotomy in borderline hip dysplasia.

INTRODUCTION: The treatment option for borderline hip dysplasia (BHD) includes hip arthroscopy and periacetabular osteotomy (PAO). To the present day the controversial discussion remains, which intervention to prefer. Literature reports supporting an educated choice are scare, based on small patient cohorts and do not address the variability of acetabular morphology. Consequently, we intended to report PAO outcomes, from patients diagnosed with BHD, dependent on acetabular morphology, in a large patient cohort and aimed to define risk factors for poor clinical results and patient satisfaction. MATERIALS AND METHODS: A prospective monocentre study was conducted. Patients enrolled underwent PAO for symptomatic BHD (LCEA, 18°-25°). A total of 107 hips were included with 94 complete data sets were available for evaluation with a minimum follow-up of 1 year and a mean follow-up of 2.3 years. The mean age was 31 ± 8.2 years, and 81.3% were female. As the primary outcome measure, we utilized the modified Harris hip score (mHHS) with minimal clinically important change (MCID) of eight to define clinical failure. Results were compared after a comprehensive radiographic assessment distinguishing between lateral deficient vs. anterior/posterolateral deficient acetabular and stable vs. unstable hip joints. RESULTS: Overall, clinical success was achieved in 91.5% of patients and the mHHS improved significantly (52 vs. 84.7, p < 0.001). Eight hips failed to achieve the MCID and four had radiographic signs of overcorrection. Comparing variable joint morphologies, the rate of clinical success was higher in patients with an anterior/posterolateral deficient acetabular covarage compared to lateral deficient acetabular (95.2% vs. 90.4%). tThe highest rate of clinical failure was recorded in unstable hip joints (85.7% vs. 92.5% in stable hips). CONCLUSIONS: This study demonstrates that PAO is an effective means to treat symptomatic BHD with variable acetabular morphologies, achieving a clinical success in 91.5% of all patients. To maintain a high level of safety and patient satisfaction technical accuracy appears crucial.

Biomechanical analysis of load distribution in porcine hip joints at different acetabular coverages.

BACKGROUND: Developmental dysplasia of the hip causes secondary osteoarthritis. Finite element analysis suggests high hip joint contact pressure in patients with hip dysplasia and a reduction in contact pressure after periacetabular osteotomy. However, few biomechanical studies have examined the load distribution in the hip joint. This study aimed to investigate the biomechanical properties of load distribution in porcine hip joints at different acetabular coverages. METHODS: Six porcine hip joints were analyzed using three models: 1) neutral coverage, 2) 15° under-coverage (defined as dysplasia model), and 3) 15° over-coverage created by varying the acetabular coverage. The load distribution was assessed using a pressure-mapping sensor system after applying a loading force of 100 N to the hip joint. RESULTS: In the dysplasia model, the load was concentrated at the acetabular rim; in the neutral and over-coverage models, it was dispersed. The average contact pressure was significantly higher in the dysplasia model than in the neutral coverage model ([0.42 vs. 0.3 MPa]; p = 0.004). The contact area was significantly smaller in the dysplasia model than in the neutral coverage model ([250.7 vs. 345.0 mm2]; p = 0.004). No significant differences were observed in contact pressure or area between the neutral and over-coverage models. CONCLUSIONS: Insufficient acetabular coverage in the dysplasia model demonstrated higher contact pressure and smaller contact area than the neutral model. Conversely, the contact pressure and area in the over-coverage model did not differ significantly from those in the normal model. Therefore, surgeons should note that acetabular coverage overcorrection has limited effect; normalization is crucial during periacetabular osteotomy.

Predictive Factors for Intraoperative Determination for the Need of Femoral Osteochondroplasty After Periacetabular Osteotomy for Acetabular Dysplasia.

Background: Determination of need for osteochondroplasty (OCP) during periacetabular osteotomy (PAO) commonly relies on intraoperative assessment of internal rotation at 90° flexion (IRF). Performing an OCP helps decrease the risk of iatrogenic femoroacetabular impingement from PAO reduction. Avoiding impingement helps decrease risks of accelerated secondary osteoarthritis. The literature is limited for factors that predict need for OCPs during PAOs. The purpose of this study was to (1) define the characteristics of patients needing concurrent OCP and provide OCP rate based on IRF and femoral version and (2) identify predictive factors (clinical, radiographic) associated with need for OCP during PAO. As some surgeons determine need for OCP pre-operatively, predictive factors would aid decision making. Methods: This was a prospective cohort of 224 hips (207 patients) who underwent PAO for symptomatic acetabular dysplasia, of which 154 hips (69%) underwent OCP between years 2013 and 2017. Patients underwent OCP if they had restrictions in motion or impingement intra-operatively. Pre-operative factors such as age, sex, BMI, and CT findings were recorded that underwent univariate and multivariable analyses. Multivariable analysis found predictors that were described using odds ratios and 95% confidence intervals. IRF>30° and femoral version 10°-25° were used as the reference groups during categorical analysis. P-values ≤0.05 were considered significant. Results: Alpha angles >55° (OR= 2.20, CI: 1.08-4.52, p= 0.03), IRF≤20° (OR: 9.52, CI: 3.87-23.40, p<0.001), IRF >20°-30° (OR: 2.68, CI: 1.08-6.62, p=0.03), and femoral version <10° (OR: 5.26, CI: 1.09-25.30, p=0.04) were associated with increased odds of OCP. On continuous modeling, decreasing femoral version (OR: 1.07, CI: 1.02-1.12, p=0.002) and IRF (OR: 1.06, CI: 1.03-1.09, p<0.001) were associated with increased chance of OCP. For 5° changes, the chance of OCP increased by 40% (OR: 1.40, CI: 1.13-1.73, p=0.002) and 35% (OR: 1.35, IC: 1.16-1.57, p<0.001), respectively. Conclusion: Awareness of need for OCP may be valuable in peri-operative planning for these patients especially since some surgeons perform this technique arthroscopically before PAO. Factors associated with increased chances of OCP were alpha angles >55°, decreased IRF, and decreased femoral version. More studies in the future would help determine how OCP affects patient outcomes. Level of Evidence: III.

Rehabilitation following periacetabular osteotomy for acetabular dysplasia: A qualitative interview study exploring challenges, hopes and expectations among patients in Denmark and Australia.

INTRODUCTION: Guidelines have been proposed for post-operative rehabilitation following periacetabular osteotomy (PAO). However, the perspectives of individuals undergoing PAO have not been considered. AIM: The present study aimed to explore the perceived challenges of everyday life and hopes for and expectations of post-PAO rehabilitation from the perspective of individuals with acetabular dysplasia living in Denmark and Australia. METHODS: In this qualitative study, we used a hermeneutic phenomenological approach with semi-structured interviews to explore the perspectives of 25 participants (four males), aged 16-43 years, who underwent a PAO. Purposeful sampling was used to provide variations in age and sex. Inclusion criteria were age above 15 years, radiographic evidence of acetabular dysplasia, PAO within the last seven weeks and undergoing post-operative rehabilitation. Inductive content analysis was adopted to code and analyse interviews. RESULTS: The analysis of the interview transcripts revealed four major themes: different expectations, self-confidence, tailored rehabilitation and aligning expectations. Several subthemes emerged within each theme, and similar patterns with minor variations were identified across countries. However, the financial burden of self-funded surgery and rehabilitation challenged some Australian participants, whereas none of the Danish participants mentioned this challenge. CONCLUSION: Our findings elucidate the diverse range of hopes and expectations in individuals undergoing PAO, and how these relate to their perceived challenges. In particular, the findings highlight the importance of aligning expectations between individuals and clinicians when designing the rehabilitation.

Peri-Operative Management of Periacetabular Osteotomy: A Report of Current Practices from the Anchor Group, Supporting Literature, and Areas for Future Investigation.

Background: Periacetabular osteotomy (PAO) is a well-established surgical treatment for hip dysplasia, but very few studies report the impact of peri-operative management strategies on early pain and function. The purpose of this study is to describe peri-operative management variability among a group of experienced surgeons and review the literature supporting these practice patterns. Methods: We surveyed 16 surgeons that perform PAO to document various aspects of peri-operative management at four stages: pre-operative, intra-operative, post-operative in the hospital, and at discharge. Our goal was to report current surgical pain management strategies, adjunct medications, type of anesthesia, deep venous thrombosis and heterotopic ossification prophylaxis strategies, initiation of physical therapy, and use of continuous passive motion (CPM). We reviewed current literature to identify studies supporting these perioperative strategies and identify knowledge gaps that would benefit from further investigation. Results: Of the 16 surgeons surveyed, 75% had been in practice greater than 10 years and most had not altered their post-operative protocol for more than 3 years. 15/16 surgeons felt that length of stay could be reduced at their institution with improved peri-operative pain management. 6/16 were considering or had already implemented outpatient PAO as a part of their practice. We found significant variability in the pain medications provided at all peri-operative stages. 14/16 utilized general anesthesia, and many utilized epidural or peripheral nerve blocks. 6/16 surgeons utilized surgical field block (also referred to as periarticular block). These surgeons advocated that surgical field block was an effective intervention with no/minimal complication risk. There is very little literature critically evaluating efficacy of these perioperative management strategies for PAO. Conclusion: There is significant practice variability in peri-operative management of PAO surgery. We report various strategies utilized by a group of experienced surgeons and review supporting literature. There are significant knowledge gaps in best surgical pain management strategies, adjunct medications, surgical field blocks, and use of CPM that need further investigation. Level of Evidence: IV.