2026年3月 保髋进展 JCR Q1

Developmental dysplasia of the hip (DDH), a morphological abnormality of the hip joint, is a well-recognized risk factor for hip osteoarthritis (OA). Much remains unknown about the genetic factors of DDH and its subtypes. To further understand its genetic basis, we conducted genome-wide association studies (GWASs) using a total of 1 085 Japanese DDH cases (including 788 hip dysplasia cases without dislocation and 297 cases with dislocated hip) and 24 000 controls. Additionally, we meta-analyzed with United Kingdom (UK) DDH GWAS and the largest hip OA GWAS to date. We identified three genome-wide significant novel loci, COL11A2, CALN1 and TRPM7, associated with hip dysplasia without dislocation. None of these signals were significant in dislocated hips, and additionally two of the signals had an opposite direction of association, suggesting distinct genetic architectures between the subtypes. The Japanese DDH GWAS identified five associated loci (VEGF-C, FOXC1, SMC2, SLC38A4, and TRPM7), and the trans-ancestry meta-analysis with UK revealed two loci (COL11A1 and GDF5) supported by strong trans-ancestry genetic correlation (r = 1.0). In total, nine loci were identified for DDH and its subtypes, with hip dysplasia without dislocation showing distinct genetic signals from hip dislocation. The meta-analysis of DDH and hip OA identified five novel signals for hip OA. Susceptibility loci and heritability enrichment analyses implicated pathways involving bone formation, collagen type XI trimer, and chondrocyte development, as well as their gene regulation, in DDH. These findings enhance understanding of the genetic architecture and biological pathways underlying DDH, providing new insights into its relationship with OA.

PURPOSE: To compare intraoperative findings associated with instability and clinical outcomes after hip arthroscopic femoroacetabular impingement syndrome (FAIS) surgery in patients with normal anteversion (NA) and excessive femoral anteversion (EA).

METHODS: Inclusion criteria were FAIS cases who underwent primary arthroscopic management from January 2016 to December 2019. Patients who met exclusion criteria, such as osteoarthritis (Tonnis grade ≧ 2), and patients with less than a 2-year follow-up were excluded. The remaining hips were divided into 2 groups: the NA group (femoral anteversion 10°-25°) and the EA group (femoral anteversion > 25°). Clinical outcomes were assessed using the International Hip Outcome Tool 12 (iHOT12), hip outcome score activity of daily living scale (HOS-ADL), hip outcome score activity of sports (HOS-SP), and modified Harris hip score (mHHS). Achievement rates for the patient acceptable symptomatic state (PASS) and the minimal clinically important difference (MCID) were also evaluated. Intraoperative findings suggestive of instability were analyzed.

RESULTS: The NA group included 34 hips, while the EA groups included 16 hips. Anteroinferior labral tears were significantly more prevalent in the EA group (75% vs 29.4%; P = .0051). Postoperative PROMs at 2 years were significantly worse in the EA group for iHOT12 (79.1 vs 95.1, P = .0017), HOS-ADL (91.2 vs 98.5, P = .0224), HOS-SP (83.3 vs 100, P = .0049), and mHHS (86.9 vs 96.8, P = .002). Regarding some PROMs, PASS achievement rates were also significantly lower in the EA group (iHot12: 56.2% vs 88.2%; P = .024, HOS-ADL: 62.5% vs 94.1%; P = .009), while no statistical difference was observed in MCID achievement rates. Three reoperations occurred in patients with EA, with femoral anteversion angles of 29°, 32.5°, and 33.5°.

CONCLUSIONS: Patients with EA had inferior outcomes of hip arthroscopy and a higher prevalence of anteroinferior labral tears.

LEVEL OF EVIDENCE: Level III, retrospective comparative case series.

Excessive femoral anteversion is related to inferior patient reports outcomes after hiparthroscopy. While hip femoral acetabular impingement is a more common diagnosis, awareness of the importance of femoral version for prognosis following hip arthroscopy is growing. An algorithm for the practical assessment of clinically significant femoral version is proposed.

Optimal management of the capsule in hip arthroscopy continues to evolve. Historically, periportal capsulotomy has been considered the more difficult and time-consuming approach because of its limited visualization and the perceived learning curve. However, as our understanding of the importance of capsular integrity has grown, so has our prioritization of preserving its stabilizing function to prevent iatrogenic instability. Periportal capsulotomy techniques embody this shift by limiting capsular disruption while still allowing adequate visualization. Recent literature challenges long-held assumptions and demonstrates that periportal capsulotomy can lead to shorter operative times and faster recovery. When performed thoughtfully, the efficiency of periportal capsulotomy may be driven by avoiding the need for an extensive closure often required after larger capsulotomies. Periportal capsulotomy may not be the easiest technique to learn, but in the right hands it can be the more efficient and biologically respectful approach. It may be the mountain worth climbing in hip arthroscopy.

BACKGROUND: Native hip instability encompasses a spectrum of abnormal pathomechanics under physiological loading and is associated with pain, dysfunction, and soft tissue damage. The condition spans a continuum-from developmental hip dysplasia to femoroacetabular impingement and even instability in the absence of bony deformities, as can be the case in patients with connective tissue disorders or soft tissue deficiencies. Despite advances in understanding this condition, biomechanical definitions, thresholds, and metrics remain inconsistent. We therefore sought to conduct a meeting with an international panel of experts to map available evidence on the biomechanical features of native hip instability, to identify knowledge gaps, and to explore whether current biomechanical metrics can reliably differentiate various degrees of severity of instability.

QUESTIONS/PURPOSES: In this scoping review and structured consensus document, we asked: (1) What are the biomechanical or pathomechanical features of native hip instability? (2) What are the biomechanical metrics of hip instability? (3) Can biomechanical metrics differentiate between hip microinstability versus conventional (bony) instability?

METHODS: A consensus study using the modified Delphi technique was conducted in accordance with the Accurate Consensus Reporting Document (ACCORD) guideline. The consensus meeting was held during the 15th Symposium on Joint Preserving and Minimally Invasive Surgery of the Hip, which took place in Québec City, Québec, Canada, in June 2025. The process involved a multidisciplinary steering committee and a diverse panel of 100 international participants representing 13 countries. Following a rapid scoping review, statements related to biomechanical or pathomechanical features of native hip instability and metrics of hip instability and hip microinstability were developed and sent to participants 1 week prior to the meeting. Participants voted on these statements across two Delphi rounds during the meeting, with consensus defined as ≥ 75% agreement.

RESULTS: The anatomic features of instability were identified as follows: bony morphology, static soft tissue stabilizers of the labrum and joint capsule, and muscles as dynamic stabilizers. Reported metrics for instability included femoral head translation, with translation 3 mm-this work contributes to a more standardized approach for defining joint stability, integrating bony morphology, capsulolabral integrity, and muscular stabilization. Such biomechanical insights guide surgical decision-making regarding capsular management and soft tissue repair and inform targeted rehabilitation strategies aimed at restoring hip stability.

BACKGROUND: The diagnosis of hip instability remains challenging because of its multifactorial etiology and the variability of imaging practices across institutions. Hip instability refers to a clinical condition of insufficient osseous and/or soft tissue constraint with abnormal femoral head motion and symptoms, which may occur along a morphologic spectrum that overlaps with-but is not synonymous with-developmental dysplasia of the hip. Although numerous imaging modalities and imaging parameters have been proposed, there is limited consensus on which are most relevant, how they should be measured, and what diagnostic thresholds best correlate with instability. To address this gap, a Delphi consensus study with an international panel of experts to establish standardized clinical statements for the diagnostic criteria of hip instability was conducted.

QUESTIONS/PURPOSES: (1) What are the imaging modalities and protocols for investigating hip instability? (2) Which imaging parameters are most strongly associated with clinical hip instability? (3) What are the quantitative imaging thresholds for diagnosing hip instability?

METHODS: A consensus study using a modified Delphi technique was conducted in accordance with the Accurate Consensus Reporting Document (ACCORD) guideline. Following a scoping review, 27 statements addressing imaging modalities and protocols (question 1), imaging parameters associated with hip instability (question 2), and quantitative imaging thresholds (question 3) were developed. These statements were evaluated by a multidisciplinary international expert panel during a structured consensus meeting, with two rounds of anonymous voting and consensus defined a priori as ≥ 75% agreement. Consensus was achieved for 81% (22 of 27) of statements.

RESULTS: There was strong agreement that radiography (AP pelvis, false-profile, Dunn view) and MRI and CT constitute the foundational imaging modalities for the assessment of hip instability, whereas cartilage mapping techniques and dynamic ultrasound were considered adjunctive modalities with a more limited and evolving role. Radiographic measurements such as lateral center-edge angle (LCEA), anterior wall index (AWI), posterior wall index, and Tönnis angle reached consensus as key morphologic indicators. Several quantitative thresholds were endorsed. An LCEA of 30°. In contrast, no consensus was reached for less-established imaging metrics such as the FEAR index, crescent sign, anterior capsule thickness, and dynamic femoral head translation.

CONCLUSION: This international Delphi consensus defined core imaging approaches and threshold values for the evaluation of hip instability. Although agreement was reached on key morphometric parameters and diagnostic thresholds, a lack of consensus exists around newer soft tissue and dynamic measures, highlighting important areas for future research.

CLINICAL RELEVANCE: In patients with suspected clinical hip instability, standard radiography should be used as the first-line imaging modality, followed by targeted use of CT and MRI to evaluate three-dimensional bony morphology and soft tissue stabilizers. Imaging findings should be interpreted within a stepwise, algorithmic framework that integrates clinical assessment with multiple complementary imaging parameters rather than relying on isolated measurements. Ultimately, accurate diagnosis of hip instability depends on the integration of findings from multiple modalities. Additionally, it must be recognized that hip instability may exist even in the absence of characteristic radiologic signs.

BACKGROUND: Computed tomography (CT)-based, artificial intelligence (AI)-assisted three-dimensional (3D) preoperative planning is increasingly used to standardize component sizing and positioning in total hip arthroplasty (THA). In complex secondary hip osteoarthritis (HOA), perioperative burden and early recovery are particularly relevant to older or medically complex patients, yet it remains unclear whether etiology still shapes these outcomes under a unified planning pathway and single implant system.

METHODS: This single-center retrospective cohort analyzed 95 consecutive cementless primary THAs for developmental dysplasia of the hip-associated

HOA (DDH-HOA, RESULTS: Planning performance was comparable (cup match 59.62% vs. 65.12%; stem match 61.54% vs. 67.44%), with similar Lewinnek/Callanan safe-zone attainment and a median leg-length discrepancy (LLD) of 1 mm in both groups. Intraoperative blood loss was lower in DDH-HOA than in post-septic HOA (212.69 ± 62.31 vs. 243.72 ± 58.64 mL,

CONCLUSION: Under a unified CT-based AI-assisted 3D planning pathway and single cementless system, sizing concordance and radiographic target attainment were similarly high across etiologies. By 24 months, PROMs were broadly comparable between groups. Post-septic sequelae were associated with greater intraoperative blood loss and less favorable pain and function at 1 month, supporting etiology-informed counseling and targeted perioperative risk mitigation.

BACKGROUND: Computed tomography (CT)-based, artificial intelligence (AI)-assisted three-dimensional (3D) preoperative planning is increasingly used to standardize component sizing and positioning in total hip arthroplasty (THA). In complex secondary hip osteoarthritis (HOA), perioperative burden and early recovery are particularly relevant to older or medically complex patients, yet it remains unclear whether etiology still shapes these outcomes under a unified planning pathway and single implant system.

METHODS: This single-center retrospective cohort analyzed 95 consecutive cementless primary THAs for developmental dysplasia of the hip-associated

HOA (DDH-HOA, RESULTS: Planning performance was comparable (cup match 59.62% vs. 65.12%; stem match 61.54% vs. 67.44%), with similar Lewinnek/Callanan safe-zone attainment and a median leg-length discrepancy (LLD) of 1 mm in both groups. Intraoperative blood loss was lower in DDH-HOA than in post-septic HOA (212.69 ± 62.31 vs. 243.72 ± 58.64 mL,

CONCLUSION: Under a unified CT-based AI-assisted 3D planning pathway and single cementless system, sizing concordance and radiographic target attainment were similarly high across etiologies. By 24 months, PROMs were broadly comparable between groups. Post-septic sequelae were associated with greater intraoperative blood loss and less favorable pain and function at 1 month, supporting etiology-informed counseling and targeted perioperative risk mitigation.

PURPOSE: Focal labral ossification is a recognized radiographic finding in developmental dysplasia (DDH) and is typically regarded as a chronic lesion resulting from excessive stress on the chondro-labral junction. The necessity for direct surgical intervention at the time of periacetabular osteotomy (PAO) for these ossifications remains a subject of debate. This study aimed to explore the natural course of pre-existing focal labral ossifications following isolated PAO in adolescents and adults, hypothesizing that biomechanical correction alone would facilitate the spontaneous resolution of this focal labral metaplasia.

METHODS: A retrospective observational subgroup analysis of an institutional database identified a single treatment group who underwent isolated PAO for symptomatic DDH in adolescents and adults between January 2022 and November 2024. Pre- and 1-year postoperative radiographs were independently assessed for the status of the labral ossification. Radiographic parameters of acetabular coverage and validated patient-reported outcome measures (PROMs) were compared between hips with and without ossification. Multivariable regression analysis was performed to identify factors associated with labral ossification.

RESULTS: Of 389 hips undergoing PAO, 41 (10%) demonstrated preoperative labral ossification. Baseline PROMs and most radiographic parameters were comparable between hips with and without ossification, although posterior coverage was significantly reduced in the ossification group. At 1-year follow-up, 37 of 41 hips (90%) showed complete radiographic resolution of labral ossification, two hips (5%) demonstrated partial regression and two hips (5%) remained unchanged. Multivariable analysis identified a mild association between posterior coverage and the presence of ossification, while no associations were found with activity level or PROMs.

CONCLUSION: Isolated PAO was found to be strongly associated with spontaneous remission of focal rim ossification in the vast majority of dysplastic hips within 1 year after surgery. These findings challenge the concept that focal rim ossifications represent irreversible degenerative pathology and instead suggest that they are a more appropriately interpreted as a metaplastic adaptation, indicating a remodeling potential of the chondro-labral junction following biomechanical correction alone. Routine surgical treatment of chronic labral ossifications at the time of PAO may therefore be unnecessary.

LEVEL OF EVIDENCE: Level III.

BACKGROUND: Patients with femoroacetabular impingement (FAI) frequently experience sacroiliac joint (SIJ) pain. Patients with concomitant lower back symptoms may be at risk for poor patient-reported outcomes after cam resection.

PURPOSE: To investigate whether SIJ stress in patients with FAI changes depending on posture or cam resection.

STUDY DESIGN: Descriptive laboratory study.

METHODS: Preoperative and postoperative computed tomography (CT) scans were analyzed in 31 patients with FAI who underwent cam resection. We created CT models of the lumbar spine, pelvis, and hip joints, including the SIJ cartilage and surrounding ligaments. For both pre- and postoperative conditions, we constructed models of standing, sitting, and sitting with 10° posterior pelvic tilt positions and measured the equivalent stress in the anterior, superior-posterior, and inferior-posterior regions of the SIJ under a 600-N load.

RESULTS: Preoperatively, the equivalent stress in the posterior-inferior SIJ region was generally higher in the sitting than in the standing position (up to 2.87-fold,

CONCLUSION: In patients with FAI, the equivalent stress in the lower portion of the SIJ generally increased in the sitting posture. Cam resection decreased the equivalent stress in the posterior-inferior SIJ region in the sitting posture to a level similar to that observed with a 10° posterior pelvic tilt before surgery.

CLINICAL RELEVANCE: These findings suggest that optimizing pelvic posture and appropriate cam resection may help mitigate SIJ-related pain in patients with FAI, providing valuable insights for surgical planning and rehabilitation strategies.

BACKGROUND: Graf's introduction of hip ultrasonography (US) in the 1980s coincided with a major change in developmental hip dysplasia (DDH) screening and diagnostic practice, with a gradual reduction in reliance on examination- and radiograph-only strategies.

METHODS: A natural language processing pipeline and non-negative matrix factorization (NLP-NMF) were applied to Scopus-indexed DDH publications, extracting topics and weights across 4 epochs (pre-1980, 1980-1984, 1985-1989, 1980-2024) anchored to the 1980 US milestone. Topic co-occurrence networks, weight distributions, and segmented regression summarized thematic shifts and tested for a 1980 breakpoint.

RESULTS: In the post-1980 corpus, a distinct diagnostic imaging theme emerged and strengthened, while surgery declined and anatomy remained influential. In 1985-1989, joint anatomy dominated (39.1%), followed by diagnosis (18.6%), pediatric orthopedics (15.3%), surgery (13.7%), and conservative treatment (13.4%). Across 1980-2024, clinical evaluation accounted for 31.5% of publications, followed by anatomy (19.6%), genetic anomaly (16.7%), diagnostic imaging (16.6%), and surgery (15.6%). Within diagnostic imaging, US carried a high weight (0.948), underscoring its central role. Segmented regression identified a structural breakpoint around 1980, temporally coincident with the period in which hip US entered clinical practice and diffused across the field.

CONCLUSION: The NLP-NMF analysis of 4 decades of DDH literature shows a sustained pivot toward imagingsupported,n clinically anchored evaluation and growing attention to etiologic and syndromic/anomaly contexts alongside anatomical determinants, with potential implications for earlier detection, risk-aligned follow-up, and more targeted use of operative management.   Cite this article as: Taşkin R, Yılar S, Budak İ, Uğur F. Ultrasonography and the reorientation of developmental hip dysplasia research: an NLP-NMF trend analysis (1980-2024). Eurasian J Med. 2026, 58 (2), 1249, doi:10.5152/eurasianjmed.2026.251249.