Developmental Disorders

Pediatric hip disorders including DDH, LCPD, and SCFE — diagnostic markers, management strategies, and prevention of early-onset arthritis.

Overview

Pediatric hip disorders encompass a spectrum of anatomical and functional abnormalities requiring early diagnosis and effective treatment to prevent disease progression and maximize long-term function [1]. While approximately 75% of infants with brachial plexus birth injury recover, up to 25% sustain long-term deficits [3]. A comprehensive nonoperative protocol for developmental dysplasia of the hip (DDH) in infants demonstrates high success rates and extremely low residual dysplasia at a mean age of five years [15]. Optimal selective screening can identify 65.6% of late-presenting children for earlier diagnosis, potentially reducing late diagnosis incidence to 0.14 per 1000 [17].

Surgical intervention is indicated for congenital dislocation of the knee complicated by bilateral hip dislocation when severe stiffness, unresponsive outcomes to conservative treatment, persistent deformities, or delayed diagnosis beyond the first month of life occur [6]. Femoral nerve palsy during Pavlik harness treatment for DDH strongly predicts treatment failure, particularly when dysplasia severity is higher [10]. For patients with frank dysplasia, periacetabular osteotomy (AAOS) is the preferred treatment, whereas no single modality is preferred for borderline hip dysplasia due to their wide spectrum of instability [84]. Preliminary data suggest surgical outcomes for late-diagnosed hip dysplasia in Prader-Willi syndrome may be comparable to non-Prader-Willi cohorts, though larger validation studies are required [26].

In arthroscopic labral repair, dysplastic cohorts exhibit outcomes and failure rates similar to rigorously matched controls at midterm follow-up [12]. For mild DDH, interventions combined with sufficient surgeon experience and properly designed implants afford a more active lifestyle with favorable implant survival in hip resurfacing [27]. The AAOS Appropriate Use Criteria serve as an educational tool to guide treatment decisions for DDH in infants up to six months, aiming to improve care quality and efficiency in the absence of high-quality comparative evidence [82].

Anatomy & Pathophysiology

Pediatric hip disorders encompass a spectrum of anatomical and functional abnormalities where early diagnosis and effective treatment are required to avoid disease progression and maximize long-term function [1]. While advancements in technology and pathomechanics understanding have increased the frequency of hip injury diagnoses in young athletes, bony hip morphology was not associated with the risk of groin injuries in male professional soccer players [33, 37]. Automatic deep learning–based 3-dimensional magnetic resonance imaging analysis provides a reliable method for analyzing the contribution of the labrum and cartilage to the joint surface in different hip deformities [38].

Classification and Morphology: The greater trochanter classification system based on anatomy and biomechanics can distinguish various types of developmental dysplasia of the hip (DDH) [20]. Patients with hip dysplasia exhibit morphological changes in the knee joint that should be considered during hip and knee surgery [43]. In young adults with hip pain and labral tears, women have smaller alpha angles [64] and hips that are generally more anteverted [64].

Ligamentous and Soft Tissue Mechanics: The ligamentum teres consistently tightens to limit hip abduction, medial rotation, and lateral rotation [47]. Intrinsic sarcomere changes contribute to the development of hip displacement in cerebral palsy [42]. Hip microinstability is characterized by abnormal femoral head micromotion within the acetabulum, leading to cartilage damage and osteoarthritis [51], and is often associated with acetabular dysplasia or femoroacetabular impingement syndrome [51].

Biomechanics and Gait: From a biomechanical perspective, rotational acetabular osteotomy is more effective in relieving hip joint stress compared with the shelf procedure and Chiari osteotomy in developmental dysplasia of the hip [41]. In biomechanical analyses, a hook on an acetabular reinforcement ring effectively disperses stress and improves the initial fixation strength in dysplastic hip arthroplasty [52]. Adults with residua of congenital dysplasia of the hip exhibit specific kinematic and kinetic gait alterations, including an abnormal pelvic position [56], increased adduction moments in severe cases [56], and alterations likely driven by pain and altered proprioceptive input [56]. In children with cerebral palsy, decreased range of motion is associated with hip pain in addition to hip displacement [58].

Pathophysiology and Treatment Principles: No method is currently known to consistently restore normal anatomy in idiopathic slipped capital femoral epiphysis without damaging the femoral head or acetabulum [49]. Effective orthopaedic management of the problematic hip in adolescent and young adult patients requires an understanding of the mechanisms of hip disease [50]. The cornerstone of treatment for prearthritic hip disease is the correction of the problematic mechanical abnormality [70]. A novel model of hip femoroacetabular impingement in immature rabbits reproduces the distinctive head-neck cam deformity [71], and this proposed model led to growth arrest at the proximal femoral physis [71].

Classification

Developmental Dysplasia of the Hip (DDH): The term "developmental dysplasia of the hip" is preferred over "congenital hip dislocation" to capture the spectrum of pathology [35]. A novel classification system based on the greater trochanter of the femur can distinguish various types of DDH and aid in surgical strategy selection [20]. Despite these advancements, a unified classification system for developmental dysplasia of the hip is still needed [35].

Legg-Calvé-Perthes Disease: Children with a lower range of abduction at diagnosis (before the fragmentation stage) developed a higher degree of lateral pillar involvement as measured by the lateral pillar classification [78]. The intra-rater reliability of the Stulberg Classification System for Legg-Calvé-Perthes disease was marginally acceptable [83]. There is significant variability between classifications assigned by different raters using the Stulberg system, even after intervention [83]. This variability calls into question the validity of treatment decisions, outcome evaluations, or epidemiological studies based on it [83].

Osteomyelitis and Skeletal Dysplasia: The OMT classification system removes contradictions present in the IFSSH system and demonstrates acceptable inter- and intraobserver reliability [69]. The OMT classification remains limited for conditions without a clear understanding of the mechanism of dysmorphology [69]. The OMT classification is regarded as a needed and appropriate replacement for the IFSSH classification with further refinements [73]. Updates on common skeletal dysplasias, including Marfan syndrome and Osteogenesis Imperfecta, are presented to guide management of associated skeletal deformities and complications [4].

Limb Lengthening and Deformity Correction: Recent advancements in limb lengthening and deformity correction include new assessment methods and classification systems for conditions such as congenital pseudarthrosis, achondroplasia, and lower-extremity deformities [62]. New techniques, classifications, and outcomes in limb lengthening and deformity correction have been highlighted across various pediatric and trauma conditions [76].

Other Considerations: Understanding the natural history and management options of hip instability is important for preventing disability and maintaining independence in the aging Down syndrome population [2]. There is a clear need for robust research into a new scoring system for generalized joint laxity with standardized methods and validated measures [85]. A new classification system for long-term unreduced hip joint dislocation, secondary osteoarthritis, and pseudoarthrosis could help surgeons estimate potential difficulties during total hip arthroplasty [86].

Clinical Presentation

Pediatric hip disorders encompass a spectrum of anatomical and functional abnormalities where early diagnosis is critical to prevent progression and maximize long-term function [1]. Greater emphasis must be placed on additional clinical signs to guide radiological screening in infants and children [5]. Optimum application of selective screening programs could have facilitated earlier diagnosis in 65.6% of late-presenting children with developmental dysplasia of the hip (DDH) [17].

Inspection and Stature: All patients with disproportionate short stature secondary to a dwarfing condition manifest spinal disorders, with kyphosis being the most common abnormality [7]. Diagnosis of hypochondroplasia is often difficult in infancy and childhood but becomes evident as characteristic growth patterns and roentgenographic features develop [14]. In adolescents or young adults presenting with hip dysplasia, clinicians should explore a neuromuscular etiology, specifically Charcot-Marie-Tooth disease [22].

Pain and Functional Complaints: Overweight or obesity is a major characteristic for boys with slipped capital femoral epiphysis (SCFE), where knee pain as an initial symptom frequently causes diagnostic delay [45]. Early-stage Legg-Calvé-Perthes disease is associated with substantial morbidity due to the frequency of pain and missed school [25]. A skeletally mature, young, active patient with insidious activity-related groin pain and/or lateral hip pain warrants investigation for DDH [54]. Affected patients with osteonecrosis secondary to DDH demonstrate minimal physical disability and a normal quality of life but reduced hip function [57].

Stability, Deformity, and Special Tests: Surgical intervention is indicated for congenital dislocation of the knee complicated with bilateral hip dislocation when severe stiffness, unresponsive outcomes to conservative treatment, persistent deformities, or delayed diagnosis beyond the first month of life are present [6]. Eight patients (17%) developed dysplasia of the contralateral hip in cases of unilateral late-detected congenital dislocation of the hip, suggesting a developmental process rather than an unnoticed dysplasia from infancy [8]. Outcomes for late-presenting developmental hip dysplasia deteriorate with increasing delay, reaching a tipping point around eight years of age after which treatment complications may yield outcomes no better than the untreated clinical course [18].

Red-Flag Patterns and Bilateral Disease: Distinguishing between concurrent and sequential onset is necessary in children with bilateral Perthes' disease as outcomes differ [23]. Children with higher GMFCS levels or dyskinetic cerebral palsy are more likely to develop scoliosis and windswept hip deformity at a younger age [40].

Investigations

Plain radiography: Pediatric hip disorders encompass a spectrum of anatomical and functional abnormalities necessitating early diagnosis to prevent progression and maximize long-term function [1]. Radiographs are critical for detecting spinal anomalies in patients with acetabular dysplasia [39] and for identifying the progression of hip disorders in cerebral palsy from subluxation to dislocation and pain [75]. In cases of disproportionate short stature secondary to dwarfing conditions, spinal manifestations, most commonly kyphosis, are universal [7]. Radiological screening in infants and children should be guided by the presence of additional clinical signs [5]. Diagnosis of slipped capital femoral epiphysis (SCFE) is often delayed, with radiological severity worsening as time to diagnosis increases [24]; notably, 6.6% of young adults exhibit radiological findings consistent with prior SCFE [67]. The posterior rim ossification sign is a normal finding in adolescent hip development that may lead to misinterpretation of acetabular coverage [79]. For metaphyseal dysostosis, roentgenographic findings can disprove previous diagnoses of rickets and osteogenesis imperfecta [74].

CT: Computed tomography demonstrates higher interobserver reliability than MRI for measuring femoral anteversion [65]. However, the diagnosis of femoral anteversion should not rely exclusively on either physical examination or radiologic criteria [65].

Other Considerations: The optimal corrective position of the acetabular fragment for developmental dysplasia of the hip is severity dependent rather than confined to the radiological normal range [66]. Clinicians should consider a neuromuscular etiology, specifically Charcot-Marie-Tooth disease, in adolescents or young adults presenting with hip dysplasia [22]. While adolescent and adult patients with longitudinal deficiencies exhibit mild-to-severe radiologic abnormalities around the shoulder girdle, these findings do not negatively affect shoulder function, with overall outcome scores remaining excellent [16]. Deformity recurrence is common in arthrogryposis and amyoplasia, particularly in skeletally immature patients [46]. Pelvic obliquity is more frequently associated with infrapelvic factors in young children, indicating a need for early awareness of this complication [63]. The greatest correction of radiological parameters and clinical outcomes for hip dysplasia in adolescence is achieved in patients who underwent hip surgery during childhood [53]. Diagnosis of hypochondroplasia is difficult in infancy and childhood but becomes evident as characteristic growth patterns and roentgenographic features develop [14].

Treatment

Pediatric hip disorders encompass a spectrum of anatomical and functional abnormalities where early diagnosis and effective treatment are paramount to altering the natural history of the disease and maximizing long-term function [1, 9]. Understanding the natural history and management options is critical for preventing disability and maintaining independence in an increasingly aging and active Down syndrome population [2].

Non-Operative

Initial Management: Nonsurgical treatment is the initial choice for almost all congenital foot deformities, with surgery generally reserved for cases where conservative measures fail to relieve symptoms or improve function [32]. For Perthes' disease diagnosed before age six, non-surgical management is advised [34]. In osteonecrosis of the femoral head associated with Gaucher disease, symptomatic management includes bed rest, analgesics, and non-weight-bearing on the involved limb during the symptomatic stage, as no known treatment effectively prevents femoral head deformity [44]. A comprehensive nonoperative protocol for developmental dysplasia of the hip (DDH) in infants demonstrates high success rates and extremely low residual dysplasia at a mean age of five years [15]. The majority of patients with residual acetabular dysplasia at two years post-brace treatment for DDH spontaneously resolve by five years [72].

Screening and Monitoring: Greater emphasis should be placed on additional clinical signs to guide radiological screening in babies and children [5]. Universal ultrasound screening of newborn infants is recommended against; however, imaging before six months of age is supported for infants with significant risk factors such as breech presentation, family history, or clinical instability [68]. Diagnostic delays in slipped capital femoral epiphysis (SCFE) are common, and radiological severity worsens with increasing time to diagnosis [24].

Operative

Indications: Surgical intervention is indicated for severe stiffness, unresponsive outcomes to conservative treatment, persistent deformities, or diagnoses and treatments occurring beyond the first month after birth [6]. For coxa vara in childhood, surgical management is indicated for progressive, painful, unilateral deformity or leg-length discrepancy, whereas moderate nonprogressive deformity often does not require surgery [61]. In situ pinning remains the preferred treatment for both stable and unstable SCFE, though residual deformity leads to high rates of subsequent disability [81]. Orthopaedic management for metaphyseal chondrodysplasia, Schmid type, is limited to deformity correction, and children should not be overtreated [55].

Surgical Approach / Technique: Early treatment using a Pavlik harness is generally safe and effective in patients younger than six months [9]. Treatment recommendations for DDH in children aged 6 months to 4 years have shifted from being based solely on age to addressing the specific disorder and avoiding iatrogenic osteonecrosis [80]. Management of early, symptomatic DDH in adolescents and young adults includes nonsurgical modalities and open joint preservation techniques [36]. A non-physeal-sparing arthroscopic approach for femoroacetabular impingement in adolescents with open physes is safe and effective, showing no evidence of clinically relevant growth arrest-related deformity or physeal instability with a minimum of one year of follow-up [60]. Early results of surgical treatment for acetabular dysplasia with labral tears indicate improved patient-reported outcome measures, though long-term evidence remains limited [13].

Implant Selection: A modular stem is recommended as a routine choice for total hip arthroplasty in patients with Crowe I and II DDH [48]. Interventions combined with sufficient surgeon experience and properly designed implants afford patients with mild DDH a more active lifestyle with favorable implant survival in hip resurfacing [27]. The early clinical efficacy of three-dimensional printing integrated acetabular prosthesis in the treatment of hip dysplasia in total hip arthroplasty is satisfactory [77].

Other Considerations: Femoral nerve palsy is strongly predictive of treatment failure in DDH, with the impact being greatest when the condition is higher in severity [10]. The aetiology of shortening and the age of the patient should be considered when deciding the surgical protocol for distraction lengthening, as congenital cases had higher complication rates and longer fixation durations [11]. Approximately 75% of infants with brachial plexus birth injury will recover, leaving up to 25% with long-term deficits [3]. Preliminary findings suggest outcomes for late diagnosed hip dysplasia in children with Prader-Willi syndrome may be comparable to those of hip dysplasia without Prader-Willi syndrome, though further studies with larger cohorts are required to validate these observations [26].

Complications

Nerve palsy: Femoral nerve palsy is strongly predictive of treatment failure in developmental dysplasia of the hip (DDH), with the impact being greatest when the DDH is higher in severity [10]. In the context of brachial plexus birth injury, approximately 75% of infants recover, leaving up to 25% with long-term deficits [3].

Instability: Early diagnosis and treatment of DDH are paramount to favorably alter the natural history of the disease [9]. Early treatment using a Pavlik harness is generally safe and effective in patients younger than 6 months [9]. The natural history of infant hip instability without subluxation or dislocation involves spontaneous normalization of the acetabular index within 3 years of age [28]. Conversely, early detection and treatment are critical to reducing complications and optimizing long-term outcomes for infants with DDH up to 6 months of age [88].

Other Considerations: Pediatric hip disorders involve a spectrum of anatomical and functional abnormalities requiring early diagnosis and effective treatment to avoid disease progression and maximize long-term function [1]. Understanding the natural history and management options is important for preventing disability in the aging Down syndrome population [2]. All patients with disproportionate short stature secondary to a dwarfing condition manifested a spinal disorder, with kyphosis being the most common abnormality [7]. Eight patients (17%) developed dysplasia of the contralateral hip, suggesting a developmental process rather than an unnoticed dysplasia from infancy [8]. Congenital forearm shortening cases exhibited higher complication rates and longer fixation durations compared to other etiologies [11]. In the dysplastic cohort, outcomes and failure rates for arthroscopic labral repair were similar to rigorously matched controls at midterm follow-up [12]. Early results of surgical treatment for acetabular dysplasia with labral tears indicate improved patient-reported outcome measures, though long-term evidence remains limited [13]. While short-term and intermediate-term results of hip preservation are favorable, evidence on long-term functional outcomes and failure rates beyond 10 years is limited [19]. Survivorship for patients with borderline dysplasia undergoing primary hip arthroscopy was 98.2% at midterm follow-up and 76.3% at long-term follow-up [21]. Total hip arthroplasty in adolescent and young adult patients demonstrated a Kaplan-Meier survivorship estimate of 95.8% at 10 and 15 years, maintained because no revisions occurred after 6 years of follow-up [29]. Recent literature has enhanced the understanding of pathoanatomy and natural history of brachial plexus birth palsy, leading to improved care [30]. Degenerative changes occurred earliest in patients with DDH, whereas the natural history of femoroacetabular impingement (FAI) was similar to structurally normal hips [31]. In reported cases of protrusio acetabuli in childhood, the deformity was almost fully present at an early age with practically no increase by age eighteen [89]. The cam deformity appears to have been nonexistent among ancient humans and is perhaps predominantly a product of modern-day stresses [90]. Despite DDH being congenital and heritable, high-quality genetic research is scarce and no genetic risk factors have been soundly established [91]. Short- and long-term outcomes of traumatic hip dislocation are largely driven by the time from injury to reduction and associated injuries [92].

Recovery

Light activity (weeks): Specific timelines for light activity or return to desk work are not explicitly defined in the available evidence for these developmental disorders. However, early-stage Legg-Calvé-Perthes disease is associated with substantial morbidity and potential social cost due to the frequency of pain and missed school [25].

Full activity (months): Evidence regarding the specific month ranges for full activity or return to sport is limited. While short-term and intermediate-term results for hip preservation are favorable, there is limited evidence on long-term functional outcomes and failure rates beyond the 10-year mark [19]. Similarly, long-term evidence regarding surgical treatment for acetabular dysplasia with labral tears remains limited [13].

Complete recovery / outcome plateau (months): The natural history of infant hip instability (without subluxation or dislocation) includes spontaneous normalization of the acetabular index within 3 years of age [28]. For brachial plexus birth injury, approximately 75% of infants will recover, while up to 25% will have long-term deficits [3]. In cases of unilateral late-detected congenital dislocation of the hip, a tipping point for outcomes is reached around eight years of age, after which complications from treatment may produce outcomes no better than the untreated clinical course [18]. Outcomes for late presenting developmental hip dysplasia deteriorate with increasing delay of presentation [18]. Despite generally good function at the latest follow-up evaluation, the prognosis for patients treated with closed reduction for congenital dysplasia of the hip remained guarded [87].

Rehabilitation protocol: Early treatment using a Pavlik harness is generally safe and effective in patients younger than 6 months with developmental dysplasia of the hip [9]. Radiographic parameters of the cervical spine in children have been documented longitudinally from before the age of three years through skeletal maturity [93].

Functional milestones: Pediatric hip disorders require early diagnosis and effective treatment to avoid disease progression and maximize long-term function [1]. Understanding the natural history and management options is important for preventing disability and maintaining independence in the aging Down syndrome population [2]. Distinguishing between concurrent and sequential onset is necessary in children with bilateral Perthes' disease as outcomes differ [23]. Adolescent and adult patients with longitudinal deficiencies of the upper limb exhibit various mild-to-severe radiologic abnormalities around the shoulder girdle, yet these did not seem to negatively affect shoulder function, as overall outcome scores were excellent [16]. The dysplastic cohort had outcomes and failure rates similar to rigorously matched controls at midterm follow-up after arthroscopic labral repair [12]. Early results of surgical treatment for acetabular dysplasia with labral tears indicate improved patient reported outcome measures [13]. Survivorship for patients with borderline dysplasia undergoing primary hip arthroscopy was 98.2% at midterm follow-up and 76.3% at long-term follow-up [21]. The Kaplan-Meier survivorship estimate for contemporary total hip arthroplasty in adolescent and young adult patients is 95.8% at 10 and 15 years, with no revisions occurring in the cohort after 6 years of follow-up [29].

Other Considerations: Eight patients (17%) developed dysplasia of the contralateral hip in cases of unilateral late-detected congenital dislocation of the hip, suggesting this appears to be a developmental process rather than an unnoticed dysplasia present from infancy [8]. Early diagnosis and treatment of developmental dysplasia of the hip is of paramount importance to favorably alter the natural history of the disease [9]. Recent literature has enhanced understanding of pathoanatomy and natural history in brachial plexus birth palsy, leading to improved care [30]. Degenerative change occurred earliest in patients with developmental dysplasia of the hip (DDH), whereas the natural history of patients with femoroacetabular impingement (FAI) was quite similar to structurally normal hips [31].

Key Evidence

• [L5] Understanding the natural history and management options is an important part of preventing disability and maintaining independence in an increasingly aging and active Down syndrome population. (10.5435/jaaos-d-17-00179)
• [L3] Greater emphasis should be placed on the presence of additional clinical signs to guide radiological screening in babies and children. (10.1302/0301-620x.100b5.bjj-2017-0994.r2)
• [Case_report] However, surgical intervention should be considered in cases with severe stiffness, unresponsive outcomes to conservative treatment, persistent deformities, or diagnoses and treatments occurring beyond the first month after birth. (10.1186/s12891-024-07316-1)
• [L4] All patients with disproportionate short stature secondary to a dwarfing condition had some manifestation of a spinal disorder, with kyphosis being the most common abnormality. (10.2106/00004623-198163090-00007)
• [L3] Eight patients (17%) developed dysplasia of the contralateral hip, which appears to be a developmental process rather than an unnoticed dysplasia present from infancy. (10.1302/0301-620x.96b9.33768)
• [L3] This complication is strongly predictive of failure of treatment, and its impact is greatest when the developmental dysplasia of the hip is higher in severity. (10.2106/jbjs.j.01210)
• [L4] The aetiology of shortening and the age of the patient should be considered when deciding the surgical protocol, as congenital cases had higher complication rates and longer fixation durations. (10.1054/jhsb.1999.0309)
• [L3] The dysplastic cohort had outcomes and failure rates similar to those of rigorously matched controls at midterm follow-up. (10.1177/0363546518767399)
• [L5] Early results indicate improved patient reported outcome measures, though long-term evidence remains limited. (10.1016/j.arthro.2022.03.010)
• [L4] The diagnosis is difficult in infancy and childhood but is evident when the characteristic growth pattern and roentgenographic features develop. (10.2106/00004623-196951040-00011)
• [L3] Our comprehensive protocol for nonoperative treatment of infant DDH has shown high rates of success and extremely low rates of residual dysplasia at a mean age of five years. (10.1302/0301-620x.105b8.bjj-2023-0149.r1)
• [L4] Adolescent and adult patients with longitudinal deficiencies exhibit various mild-to-severe radiologic abnormalities around the shoulder girdle, but these findings did not seem to negatively affect shoulder function as the overall outcome scores were excellent. (10.1016/j.jse.2023.05.025)
• [L4] With optimum application of the selective screening programme, 65.6% of late-presenting children had the potential for an earlier diagnosis, which would have reduced the incidence of late diagnosis to 0.14 per 1000. (10.1302/0301-620x.97b11.35286)
• [L4] Outcomes deteriorate with increasing delay of presentation, with a tipping point reached around eight years of age after which complications from treatment may produce outcomes no better than the untreated clinical course. (10.1302/0301-620x.97b6.35395)
• [L5] While short-term and intermediate-term results are favorable, there is limited evidence on long-term functional outcomes and failure rates beyond the 10-year mark. (10.1007/s00167-023-07409-9)
• [L3] The greater trochanter classification system based on the anatomy and biomechanics could distinguish various types of DDH and aid in making surgical strategies. (10.1016/j.arth.2025.08.013)
• [L4] Survivorship at midterm follow-up was 98.2% and 76.3% at long-term follow-up. (10.1016/j.arthro.2022.12.030)
• [L4] The authors recommend that clinicians explore a neuromuscular etiology, specifically Charcot-Marie-Tooth disease, in adolescents or young adults presenting with hip dysplasia. (10.2106/00004623-199507000-00017)
• [L2] Distinguishing between concurrent and sequential onset is necessary as outcomes differ. (10.1302/0301-620x.98b4.36045)
• [L3] Diagnostic delays were common and radiological severity worsened with increasing time to diagnosis. (10.1302/0301-620x.104b4.bjj-2021-1709.r1)
• [L2] This prospective study provides a new international multicenter representation of early LCPD, highlighting the substantial morbidity and potential social cost and burden for children and families due to the frequency of pain and missed school. (10.5435/jaaos-d-19-00379)
• [L4] While preliminary findings suggest outcomes may be comparable to those of HD without PWS, further studies with larger cohorts are required to validate these observations. (10.1186/s12891-025-08470-w)
• [L3] The interventions reported here, combined with sufficient surgeon experience and properly designed implants, afford patients with mild developmental dysplasia a more active lifestyle with favorable implant survival. (10.1186/s12891-016-1095-7)
• [L3] The natural history of infant hip instability (without subluxation or dislocation) has spontaneous normalization of the acetabular index within 3 years of age. (10.1186/1471-2474-15-355)
• [L5] The authors clarify that the Kaplan-Meier survivorship estimate of 95.8% at 10 and 15 years is maintained because no revisions occurred in the cohort after 6 years of follow-up. (10.1016/j.arth.2025.02.048)
• [L5] Recent literature has enhanced understanding of pathoanatomy and natural history, leading to improved care. (10.1016/j.jhsa.2009.11.026)
• [L3] Degenerative change occurred earliest in patients with DDH, whereas the natural history of patients with FAI was quite similar to structurally normal hips. (10.1007/s11999-016-4815-2)
• [L5] Hip injuries in young athletes are being diagnosed with increasing frequency due to advancements in technology and understanding of pathomechanics. (10.5435/jaaos-21-11-665)
• [L3] Non-surgical management should be advised in children in whom the diagnosis of Perthes' disease is made before the age of six years. (10.1302/0301-620x.107b5.bjj-2024-1160.r2)
• [Letter] The term 'developmental dysplasia of the hip' is preferred over 'congenital hip dislocation' to capture the spectrum of pathology, though a unified classification system is still needed. (10.1007/s11999-008-0630-8)
• [L5] Management of early, symptomatic DDH includes nonsurgical modalities and open joint preservation techniques. (10.5435/jaaos-d-18-00533)
• [L2] Bony hip morphology was not associated with the risk of groin injuries. (10.1177/0363546518763373)
• [L4] This study paves the way for a more in-depth understanding of the underlying pathomechanism and a reliable 3D analysis of the hip joint that can be indicative for surgical decision-making in patients with hip deformities. (10.1177/03635465251339758)
• [L3] Patients with acetabular dysplasia have an increased frequency of spinal anomalies seen on standard hip radiographs. (10.1302/0301-620x.103b8.bjj-2020-2481.r1)
• [L2] Children with higher GMFCS level or dyskinetic CP are more likely to develop these deformities at a younger age. (10.1186/s12891-024-07350-z)
• [L5] From biomechanics points, RAO was more effective in relieving hip joint stress compared with shelf procedure and Chiari osteotomy. (10.1186/1471-2474-15-47)
• [L3] These findings suggest intrinsic sarcomere changes contribute to the development of hip displacement. (10.1186/s13018-019-1239-1)
• [L2] These changes should be considered during hip and knee surgery. (10.1007/s00167-012-2242-9)
• [L4] The authors recommend symptomatic management with bed rest and analgesics followed by non-weight-bearing on the involved limb during the symptomatic stage of bone crisis, as no known treatment effectively prevents femoral head deformity. (10.2106/00004623-199601000-00003)
• [L3] Overweight or obesity is a major characteristic for boys with SCFE, while knee pain as an initial symptom causes a delay in diagnosis. (10.1186/s12891-017-1665-3)
• [L5] Deformity recurrence is common, particularly in skeletally immature patients. (10.5435/00124635-200211000-00006)
• [L5] The ligamentum teres consistently tightened to limit hip abduction, medial rotation, and lateral rotation. (10.1007/s00167-012-2262-5)
• [L3] We recommend the modular stem as routine choice for these patients. (10.1186/s13018-019-1408-2)
• [L5] No method of consistently restoring normal anatomy without damaging the femoral head or acetabulum is known. (10.2106/jbjs.17.00015)
• [L5] Effective orthopaedic management requires an understanding of the mechanisms of hip disease as well as surgical expertise. (10.5435/00124635-201105000-00005)
• [Paper] In biomechanical analyses, the hook effectively dispersed stress and improved the initial fixation strength of the acetabular reinforcement ring. (10.1186/s13018-018-1023-7)
• [L3] The greatest correction of radiological parameters and clinical outcomes was found in patients who had undergone hip surgery in childhood. (10.1302/0301-620x.104b7.bjj-2021-1771.r1)
• [L4] The diagnosis of developmental dysplasia of the hip should be suspected and investigated when a skeletally mature, young, active patient has a predominant complaint of insidious activity-related groin pain and/or lateral hip pain. (10.2106/jbjs.j.01735)
• [L4] Orthopaedic management is limited to the correction of deformity, and children should not be overtreated. (10.2106/00004623-198062040-00023)
• [L4] The study demonstrates that adults with residua of congenital dysplasia of the hip exhibit specific kinematic and kinetic gait alterations, including an abnormal pelvic position and increased adduction moments in severe cases, which are likely driven by pain and altered proprioceptive input. (10.2106/00004623-199610000-00003)
• [L3] Affected patients demonstrated minimal physical disability, a normal quality of life but reduced hip function. (10.1186/s12891-020-03865-3)
• [L3] In addition to hip displacement, decreased range of motion was also associated with hip pain. (10.1186/s12891-019-2449-8)
• [L4] A non-physeal-sparing arthroscopic approach for FAI in adolescents with open physes is safe and effective with no evidence of clinically relevant complication of growth arrest-related deformity or physeal instability in patients with a minimum of 1 year of follow-up after surgery. (10.1016/j.arthro.2019.01.029)
• [L5] Surgical management is indicated for progressive, painful, unilateral deformity or leg-length discrepancy, while moderate nonprogressive deformity often does not require surgery. (10.5435/00124635-199803000-00003)
• [L5] This update summarizes recent advancements in limb lengthening and deformity correction, including new assessment methods, classification systems, surgical techniques, and outcomes across various conditions such as congenital pseudarthrosis, achondroplasia, and lower-extremity deformities. (10.2106/jbjs.23.00310)
• [L3] Pelvic obliquity was more often associated with infrapelvic factors and seen in young children, indicating the need for early awareness of this complication. (10.1186/s12891-020-03484-y)
• [L3] In young adults with hip pain and labral tears, women have smaller alpha angles and hips that are generally more anteverted. (10.1016/j.arthro.2012.07.008)
• [L3] CT was found to have higher interobserver reliability than MRI, and diagnosis should not rely exclusively on either examination or radiologic criteria. (10.1016/j.arthro.2011.10.021)
• [L5] The optimal corrective position of the acetabular fragment is severity dependent rather than within the radiological normal range for developmental dysplasia of the hip. (10.1186/s13018-016-0445-3)
• [L3] This study indicates that 6.6% of young adults have radiological findings consistent with a prior SCFE, which seems to be more common than previously reported. (10.1302/0301-620x.95b4.29910)
• [L1] The guideline recommends against universal ultrasound screening of newborn infants but supports imaging before 6 months of age for infants with significant risk factors such as breech presentation, family history, or clinical instability. (10.5435/jaaos-d-15-00006)
• [L4] The OMT classification removes contradictions present in the IFSSH system and demonstrates acceptable inter- and intraobserver reliability, though it remains limited for conditions without a clear understanding of the mechanism of dysmorphology. (10.1016/j.jhsa.2013.03.019)
• [L5] The cornerstone of treatment of the prearthritic hip is the correction of the problematic mechanical abnormality. (10.2106/jbjs.20.01494)
• [L5] The proposed model led to growth arrest at the proximal femoral physis, resulting in a femoral head-neck deformity similar to human FAI. (10.1177/03635465221090645)
• [L3] The majority of patients with residual acetabular dysplasia at two years post-brace treatment spontaneously resolved by five years. (10.1302/0301-620x.106b7.bjj-2023-1169.r1)
• [L3] With further refinements, we regard the OMT classification as a needed and appropriate replacement for the IFSSH classification. (10.1016/j.jhsa.2013.11.014)
• [L4] Histological and roentgenographic findings in a child with metaphyseal dysostosis disprove previous diagnoses of rickets and osteogenesis imperfecta. (10.2106/00004623-197355030-00021)
• [L5] Hip disorders in cerebral palsy progress from subluxation to dislocation and pain, requiring early detection via radiographs and comprehensive treatment including soft-tissue lengthening or one-stage reconstruction; salvage options for skeletally mature patients with neglected hips remain limited. (10.5435/00124635-200205000-00006)
• [L5] This Specialty Update summarizes recent research and major events in limb lengthening and deformity correction, highlighting new techniques, classifications, and outcomes across various pediatric and trauma conditions. (10.2106/jbjs.16.00460)
• [L4] The early clinical efficacy is satisfactory. (10.1016/j.arth.2025.05.024)
• [L3] Children with a lower range of abduction at diagnosis (before the fragmentation stage) developed a higher degree of lateral pillar involvement as measured by the lateral pillar classification. (10.1186/s12891-020-03705-4)
• [L3] The posterior rim ossification sign is a normal finding in adolescent hip development that can lead to misinterpretation of acetabular coverage on radiographs. (10.2106/jbjs.n.00553)
• [L5] Treatment recommendations for DDH in children aged 6 months to 4 years have shifted from being based solely on age to addressing the specific disorder and avoiding iatrogenic osteonecrosis. (10.5435/00124635-200111000-00005)
• [L5] The AAOS Appropriate Use Criteria provide an educational tool to guide clinicians through treatment decisions for DDH in infants up to six months, aiming to improve care quality and efficiency in the absence of high-quality comparative evidence. (10.5435/jaaos-d-18-00499)
• [L4] Although intra-rater reliability was marginally acceptable, the degree of variability between the classifications assigned by different raters — even after the intervention — calls into question the reliability of the system of Stulberg et al.; consequently, the validity of any treatment decisions, outcome evaluations, or epidemiological studies based on this system is also in question. (10.2106/00004623-199909000-00002)
• [L5] While the data support that patients with frank dysplasia are best treated with PAO, there is no such preferred treatment for patients with BHD, who have a wide spectrum of instability. (10.1177/0363546519881411)
• [Commentary] There is a clear need for robust research into a new scoring system with standardized methods and validated measures. (10.1016/j.arthro.2025.08.013)
• [L4] The new classification system could help surgeons estimate potential difficulties during total hip arthroplasty. (10.1186/s12891-020-03678-4)
• [L3] Despite generally good function at the latest follow-up evaluation, the prognosis for these patients remained guarded. (10.2106/00004623-199412000-00004)
• [L5] Early detection and treatment is critical to reducing complications and optimizing outcomes for patients in the long term. (10.5435/jaaos-d-18-00500)
• [L4] In the reported cases, the deformity was almost fully present at an early age with practically no increase by age eighteen. (10.2106/00004623-196345020-00017)
• [L4] The cam deformity appears to have been nonexistent among ancient humans and is perhaps predominantly a product of modern-day stresses. (10.2106/jbjs.o.00169)
• [L1] Despite DDH being known to be congenital and heritable, high quality genetic research is scarce and no genetic risk factors have been soundly established, prompting the need for more research. (10.1186/s12891-024-07795-2)
• [L5] Short and long-term outcomes are largely driven by the amount of time from injury to reduction and associated injuries. (10.5435/jaaos-d-23-01013)
• [L3] The measurements presented in the current study are important because they are the first, as far as we know, to document the radiographic parameters of the cervical spine in children who were followed longitudinally from before the age of three years through the course of growth and development until skeletal maturity. (10.2106/00004623-200108000-00011)

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[92] Traumatic Hip Dislocation: Pediatric and Adult Evaluation and Management. Journal of the American Academy of Orthopaedic Surgeons. 2024. DOI: 10.5435/jaaos-d-23-01013

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