DDH Group Research Articles

A Modified Approach to Measuring Femoro-Epiphyseal Acetabular Roof (FEAR) Index Has Better Intraobserver and Interobserver Reliability Compared With the Original FEAR Index

PurposeTo propose a modified approach to measuring femoro-epiphyseal acetabular roof (FEAR) index while still abiding by its definition and biomechanical basis, and to compare the intra- and inter-observer reliabilities of the original and the modified FEAR index. To propose a classification for medial sourcil edges. MethodsWe retrospectively reviewed a consecutive series of patients treated with periacetabular osteotomy and/or hip arthroscopy at a single institute. Patients with unilateral or bilateral symptomatic borderline hip(s) were included. Hips with remarkable osteoarthritis, deformities, history of previous surgery, or without symptoms were excluded. A modified FEAR index was defined using a best-fit circle to determine the sourcil line and two ancillary lines connecting femoral head and sourcil edges to determine epiphyseal line. Lateral center-edge angle, Sharp’s angle, Tonnis angle on all hips, as well as FEAR index with original and modified approaches were measured. Intra- and inter-observer reliability were calculated as intraclass correlation coefficients (ICC) for FEAR index with both approaches and other alignments. A classification was proposed to categorize medial sourcil edges. ICC for the two approaches across different sourcil groups were also calculated. ResultsAfter reviewing 411 patients, 49 were finally included. Thirty-two patients (40 hips) were identified as having borderline dysplasia defined by an LCEA of 18 to 25 degrees. Intra-observer ICC for the modified method were good to excellent for borderline hips; poor to excellent for DDH; moderate to excellent for normal hips. As for inter-observer reliability, modified approach outperformed original approach with moderate to good inter-observer reliability (DDH group, ICC=0.650; borderline dysplasia group, ICC=0.813; normal hip group, ICC=0.709). The medial sourcil edge were classified to 3 groups upon its morphology. Type II (39.0%) and III (43.9%) sourcils were the dominant patterns. The sourcil classification had substantial intra-observer agreement (observer 4, kappa=0.68; observer 1, kappa=0.799) and moderate inter-observer agreement (kappa=0.465). Modified approach to FEAR index possessed greater inter-observer reliability in all medial sourcil edge patterns. ConclusionThe modified FEAR index has better intra- and inter-observer reliability compared with the original approach in all hip groups and sourcil groups. Type II and III sourcils accounts for the majority to which the modified approach is better. Level of EvidenceLevel II, Development of diagnostic criteria (consecutive patients with consistently applied reference standard and blinding)

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

BackgroundDevelopmental dysplasia of the hip (DDH) encompasses a range of hip disorders, from dysplasia to dislocation. One key factor is sex, with women being four to eight times more susceptible to DDH than men. However, there have been no studies investigating the second-to-fourth digit ratio (2D:4D), a biomarker of prenatal sex steroid exposure, in DDH patients. This study aimed to explore whether there is an association between the 2D:4D ratio and DDH. MethodsDigital calipers were used to measure the second and fourth finger lengths of 250 patients treated for DDH and 200 patients in the healthy control group between January 2020 and January 2023. The Mann-Whitney U test was used for non-normally distributed variables and two-way analysis of variance to assess differences in measurements between DDH patients based on sex, side, and the interaction of sex and side. The intraclass correlation coefficient (ICC) was used to assess measurement repeatability. ResultsThe median (min-max) age was 10.00 (6–16) years in the DDH group, 12.00 (6–16) years in the control group, and 10 (6–16) years for the whole cohort. There was no significant difference in terms of age between the patient and control groups (p = 0.083). When comparing the DDH group with controls the former showed higher right 2D:4D and Δ2D:4D and these differences were significant in both males and females. Among the patients, controlling for side of dysplasia did not affect right 2D:4D, left 2D:4D or Δ2D:4D. ConclusionThere was a significant association between higher 2D:4D ratios (both right and left hands) and DDH in both men and women. This indicates that the 2D:4D ratio, a marker of intrauterine estrogen/testosterone balance, is associated with DDH.

A MODIFIED APPROACH TO MEASURING FEMORO-EPIPHYSEAL ACETABULAR ROOF (FEAR) INDEX: ASSESSING THE INTRAOBSERVER AND INTEROBSERVER RELIABILITY

To propose a modified approach to measuring femoro-epiphyseal acetabular roof (FEAR) index while still abiding by its definition and biomechanical basis, and to compare the reliabilities of the two methods. To propose a classification for medial sourcil edges.We retrospectively reviewed a consecutive series of patients treated with periacetabular osteotomy and/or hip arthroscopy. A modified FEAR index was defined. Lateral center-edge angle, Sharp's angle, Tonnis angle on all hips, as well as FEAR index with original and modified approaches were measured. Intra- and inter-observer reliability were calculated as intraclass correlation coefficients (ICC) for FEAR index with both approaches and other alignments. A classification was proposed to categorize medial sourcil edges. ICC for the two approaches across different sourcil groups were also calculated.After reviewing 411 patients, 49 were finally included. Thirty-two patients (40 hips) were identified as having borderline dysplasia defined by an LCEA of 18 to 25 degrees. Intra-observer ICC for the modified method were good to excellent for borderline hips; poor to excellent for DDH; moderate to excellent for normal hips. As for inter-observer reliability, modified approach outperformed original approach with moderate to good inter-observer reliability (DDH group, ICC=0.636; borderline dysplasia group, ICC=0.813; normal hip group, ICC=0.704). The medial sourcils were classified to 3 groups upon its morphology. Type II(39.0%) and III(43.9%) sourcils were the dominant patterns. The sourcil classification had substantial intra-observer agreement (observer 4, kappa=0.68; observer 1, kappa=0.799) and moderate inter-observer agreement (kappa=0.465). Modified approach to FEAR index possessed greater inter-observer reliability in all medial sourcil patterns.The modified FEAR index has better intra- and inter-observer reliability compared with the original approach. Type II and III sourcils accounts for the majority to which only the modified approach is applicable.

EARLY TO MID-TERM OUTCOMES OF PERIACETABULAR OSTEOTOMY FOR DEVELOPMENTAL HIP DYSPLASIA AND FEMOROACETABULAR IMPINGEMENT: A STUDY OF 1,087 CASES USING THE NAHR DATASET

Periacetabular osteotomy (PAO) is an established treatment for developmental hip dysplasia (DDH) in young adults and can also be utilised in the management of femoroacetabular impingement (FAI) with acetabular retroversion. This study used a national registry to assess the outcomes of PAO for DDH and FAI.PAOs recorded in the UK Non-Arthroplasty Hip Registry between 2012 and November 2022 were identified along with recorded patient and surgical characteristics. Cases were grouped according to the primary pathology (DDH or FAI). Patient reported outcome measures (PROMs) captured included the International Hip Outcome Tool (iHOT)-12 (primary outcome) and the EuroQol-5 Dimensions (EQ-5D) index preoperatively and at 6 months, 1, 2, and 5 years post-operatively.1,087 PAOs were identified; 995 for DDH (91%), 98 for FAI (9%). Most patients (91%) were female. The DDH group were significantly older (mean 31.7 years) than the FAI group (25.4 years) but had similar body mass index (mean 25.7kg/m2). Overall, significant (all p<0.0001) iHOT-12 and EQ-5D improvement (delta) vs baseline pre-operative scores were achieved at 6 months (mean iHOT-12 improvement +27.4 (95%CI 25.3 to 29.5); n=515) and maintained out to 5 years (+30.0 (21.4 to 38.6); n=44 [9.8% of those eligible for follow-up at 5 years]), at which point 71% and 55% of patients continued to demonstrate a score improvement greater than or equal to the minimum clinically important difference (≥13 points) and substantial clinical benefit (≥28 points) for iHOT-12 respectively.This study demonstrates excellent functional outcomes following PAO undertaken for DDH and FAI in the short to medium term in a large national registry.

Characteristics and Outcomes of Patients Discharged Directly Home From the Pediatric Intensive Care Unit.

Introduction: Patients admitted to the pediatric intensive care unit (PICU) typically transfer to an acute care floor prior to discharge (ACD). Various circumstances, including rapid clinical improvement, technology dependence, or capacity constraints, may lead to discharge directly to home from a PICU (DDH). This practice has been studied in adult intensive care units, but research is lacking for PICU patients. Methods: We aimed to describe characteristics and outcomes of patients requiring PICU admission who experienced DDH versus ACD. We conducted a retrospective cohort study of patients ≤18 years old admitted to our academic, tertiary care PICU between 1/1/15 and 12/31/20. Patients who died or were transferred to another facility were excluded. Baseline characteristics (including home ventilator dependence) and markers of illness severity, specifically the need for vasoactive infusion or new mechanical ventilation, were compared between groups. Admission diagnoses were categorized using the Pediatric Clinical Classification System (PECCS). Our primary outcome was hospital readmission within 30 days. Results: Of 4042 PICU admissions during the study period, 768 (19%) were DDH. Baseline demographic characteristics were similar, although DDH patients were more likely to have a tracheostomy (30% vs 5%, P < .01) and require a home ventilator at discharge (24% vs 1%, P < .01). DDH was associated with being less likely to have required a vasoactive infusion (7% vs 11%, P < .01), shorter median length of stay (LOS) (2.1 days vs 5.9 days, P < .01) and increased rate of readmission within 30 days of discharge (17% vs 14%, P < .05). However, repeat analysis after removing ventilator-dependent patients at discharge (n = 202) showed no difference in rates of readmission (14% vs 14%, P = .88). Conclusions: Direct discharge home from the PICU is a common practice. DDH and ACD groups had similar 30-day readmission rate when patient admissions with home ventilator dependence were excluded.

Contemplate iliosacral screw in patients with developmental dysplasia of the hip

ObjectivesOur aim in the study was evaluating sacroiliac morphology in patients with DDH and its possible effect on appropriate iliosacral screw fixation.DesignRetrospective cohort study.SettingLevel of evidence 3.Patients/participantsWe evaluated the anteroposterior pelvis X-ray and pelvic CT scans of patients. We mainly divided the patients into two groups: DDH group (n:105) and control group (n:105).InterventionThe presence of the five qualitative characteristics of sacral dysplasia evaluated according to Route in both groups. The DDH group was divided into four subgroups according to the degree of hip dysplasia.Main outcome measurementThe cross-sectional area, length of the osseous corridor, coronal and vertical angulation evaluated in both groups.ResultsThe DDH group also exhibited a significantly higher S1 coronal and axial angulation, lower S1 cross-sectional area and S1 iliosacral screw length than the control group (p:0.033, p:0,002, p:0.006, p:0,019, respectively). According to the Rout classification, 9% were normal, 31% transient, 58% dysplastic in the DDH group. 45.7% were normal, 38% transient, 17% dysplastic in the control groups. These differences between the groups were statistically significant (p < 0.001). When the DDH groups were evaluated within themselves; no statistically significant difference was observed in S1 and S2 cross-sectional area, S1 and S2 maximum estimated iliosacral screw length, S1 and S2 axial and coronal angles assessment.ConclusionSacral dysplasia was more common, narrower and more angled osseous canal for the iliosacral screw was found in the DDH group. There was no relation between the degree of hip dysplasia and sacrum morphology in the DDH group. Thus, we suggest the surgeons be aware of iatrogenic injury even in constrained dysplastic hips.

Biomechanical Characteristics of the Femoral Isthmus during Total Hip Arthroplasty in Patients with Adult Osteoporosis and Developmental Dysplasia of the Hip: A Finite Element Analysis

This study investigated the underlying mechanisms of high fracture incidence in the femoral isthmus from a biomechanical perspective. We retrospectively analyzed a total of 923 primary total hip arthroplasty (THA) patients and 355 osteoporosis (OP) patients admitted from January 2010 to January 2018. Through a series of screening conditions, 47 patients from each group were selected for inclusion in the study. The datasets on the unaffected side and affected side of the patients with unilateral developmental dysplasia of the hip (uDDH) were respectively classified as the normal group (Group I) and he tDDH group (Group II), and that of patients with osteoporosis were classified as the OP group (Group III). In this study, first, we collected computed tomography (CT) images and measured geometric parameters (inner and outer diameters) of the isthmus. Thereafter, to study biomechanical properties, we established six finite element models and calculated values of von Mises stress for each group with the methods of data conversion and grid processing. Compared with those of patients in the normal group, the values of the inner and outer diameters of femoral isthmus of patients in the DDH group were significantly lower (P < 0.001), while the inner diameters of patients in the OP group were significantly higher (P < 0.001) and the outer diameters of patients in the OP group showed no significant difference (P> 0.05). The cortical rates of patients in the normal group and the DDH group appeared insignificant (P > 0.05), and those of patients in normal group were significantly higher than those of patients in the OP group (P < 0.001). Moreover, patients in the DDH group showed a higher von Mises stress value than patients in the normal group (P < 0.001), but statistically speaking the values between patients in the OP and normal groups were insignificant (P > 0.05). The relatively shorter inner and outer diameters of the isthmus in DDH resulted in intensive von Mises stress under the torque of the hip location, and induced a high fracture incidence. However, in patients in the OP group, the geometric morphology exhibited no anatomical variation, and the fracture was not due to the intensity of von Mises stress.

Patient-specific total hip arthroplasty is superior to conventional methods for Crowe III and IV adult developmental hip dysplasia: a randomized controlled trial.

BackgroundRestoration of the acetabulum during total hip arthroplasty in adults with developmental dysplasia of the hip (DDH-THA) and resumption of hip function remain major challenges. Herein, a new patient-specific instrument (PSI) was developed that uses the superolateral rim of the acetabulum as a positioning marker to assist surgeons in adult DDH-THA.MethodsFrom January 2017 to October 2018, 104 adult DDH patients were randomized to either the PSI group or conventional operation (CO) group, and further divided into eight subgroups by stratified random sampling using Crowe’s classification. Complications, Harris hip scores (HHS), and X-ray results were recorded at 3 and 12 months after surgery.ResultsWith the exception of anteversion in CO-Crowe II group patients, there was no difference in the accuracy of cup placement and orientation between the PSI and CO groups in Crowe I and II DDH patients. With the exception of percentage of acetabular cup coverage (PACC) and the qualification rate of Crowe IV PACC patients, among all Crowe III and IV DDH groups, all postoperative indexes of cup orientation and positioning exhibited significant differences between the PSI and CO groups; however, no significant differences were observed in Crowe I and II DDH patients.ConclusionsCompared with conventional methods, the new PSI-assisted surgical method improved the accuracy of placement and orientation of the acetabulum and cup prosthesis, optimized the surgical process, reduced complications, and contributed to quicker recovery of hip function after surgery in adults with Crowe III and IV DDH-THA, but little difference was noted for those with Crowe I and II DDH.

Are vitamin D and vitamin D receptor levels different in children with developmental dysplasia of the hip?

IntroductionDevelopmental dysplasia of the hip (DDH) is a common disorder and associated with significant morbidity of the hip joint. Several risk factors have been identified for DDH. The aim of this study is to investigate whether vitamin D and vitamin D receptor (VDR) levels differ in children with DDH and whether they have an effect on DDH development.Materials and methodsA total of 40 (17 males, 23 females; 9 right hips, 16 left hips, 15 bilateral hips) children who were treated for developmental dysplasia and 40 (23 males, 17 females) healthy children without any musculoskeletal system and metabolic disorders were included in this study between January and June 2019. Blood samples from the DDH and control groups of children were collected to measure the serum levels of vitamin D, VDR, calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP). The levels of Ca, P, and ALP were analyzed using the automated standard spectrophotometric laboratory method. The levels of vitamin D and VDR in the samples were analyzed using enzyme-linked immunoassay.ResultsThere were no significant differences in the serum levels of Ca, P, ALP, and vitamin D between the DDH and healthy groups (Ca 9.96 ± 0.47 vs. 9.92 ± 0.48 mg/dL, respectively, p = 0.721; P 5.3 ± 0.94 vs. 4.82 ± 0.88 mg/dL, respectively, p = 0.23; ALP 252.22 ± 170.15 vs. 245.3 ± 130.93 U/L, respectively, p = 0.839). However, serum VDR levels were significantly lower in children in the DDH group (5.77 ± 3.51 ng/mL) than in the healthy control group (9.25 ± 6.43 ng/mL) (p = 0.004).ConclusionsIn conclusion, we believe that low VDR levels can affect DDH regardless of the serum levels of Ca, P, ALP, and vitamin D. More comprehensive studies involving parents are needed to understand whether VDR levels mediate genetic transmission in DDH or not.

Survival Analysis of Total Hip Arthroplasty for High Hip Dislocation Secondary to Developmental Dysplasia or Septic Arthritis of the Hip

BackgroundThis retrospective study was conducted to know clinical and radiographic outcomes, complication rate, and survival of THA in patients with high hip dislocation secondary to developmental dysplasia(DDH) or septic arthritis of the hip(SSH). MethodsBetween March 2005 and September 2014, there were consecutive series of 53 THAs in patients with a highly dislocated hip secondary to DDH or SSH. Of these, 48 hips (DDH 24 and SSH 24) were reviewed at a mean follow-up of 7.9 years(range, 5.0-14.3 years). The mean age at the time of THA was 39.1 years(range, 18.0-59.0 years). ResultsIntraoperative blood loss, total drainage and blood transfusion amounts, and mean time to greater trochanter union were significantly lower in the DDH group than in the SSH group (P = .001, P = .039 and P = .014, and P = .015, respectively). No significant difference in Kaplan–Meier survivorship was observed between groups (log-rank, P = .343). The survival rates with an endpoint of cup aseptic loosening in cases with a cemented cup at 7.9 and 10 years (68.1% and 60.5%, respectively) were significantly lower than those in cementless cup cases (100%) at the same checkpoints (P = .019).. ConclusionWe found similar clinical outcomes between the DDH and SSH groups. However, due to poor bone quality and a lack of containment, cementless acetabular cups could not be performed in more than 50% of patients. Our experience shows that revision cementless fixation cup was possible due to reconstitution of the acetabulum in cases with failed cemented fixation.

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

BackgroundThe purpose of this study was to use the American College of Surgeons National Surgical Quality Improvement Program to compare the perioperative and postoperative outcomes after total hip arthroplasty (THA) for DDH and primary OA via a propensity-matched pair analysis and the valuation of THA between both groups.Material and MethodsAll patients who underwent THA between 2008 and 2016 were identified from National Surgical Quality Improvement Program database via the current procedural terminology (CPT) code. Patients were further identified and stratified based on International Statistical Classification of Diseases and Related Health Problems–9/International Statistical Classification of Diseases and Related Health Problems–10 diagnosis codes for primary OA (n = 115,166) and DDH (n = 603), which included codes for congenital hip dislocation, hip dysplasia, or juvenile osteochondrosis. Demographic variables were used to create 557 propensity-matched pairs.ResultsThe DDH group was associated with a significantly longer operative time (120.3 vs 95.9 min), higher postoperative transfusion rate (12% vs 6.6%), and longer hospital length of stay (2.8 vs 2.5 days) compared with the primary OA group (P < .001, P < .001, and P = .002, respectively). There were no statistically significant differences found between the two groups with respect to inpatient complications, discharge disposition (P = .123), readmissions (P = .615), or reoperations (P = .404).ConclusionsHealth policy makers should be cognizant of the higher complexity of THA for DDH when determining whether DDH and primary OA should be in the same bundle. Owing to the limitations of our data set, all the observed associations are likely an underestimate of the true risk posed to patients with severe DDH, as these patients were unable to be stratified in the present analysis.

Comparison of Valgus Correction Angle between Patients with Developmental Dysplasia Hip and Normal Volunteers Measured by Three-Dimensional Reconstruction and X-Ray.

Methods Bilateral VCA of 50 DDH patients and 56 normal volunteers were measured by Mimics software in the 3D method and X-ray in 2D. Two VCA (the upper VCA and the lower VCA) were measured in both two methods. Every VCA was measured by observer A and observer B for twice separately. The statistical analyses of the differences were calculated among the measurements of the VCA. Results The mean value of the upper VCA measured in 3D was 4.95° ± 0.76° in DDH group and 5.56° ± 0.62° in the normal group with significant difference (t = −6.457, p < 0.01). The VCA of DDH group and normal group measured by 3D was larger than 2D, both the upper VCA and the lower VCA. The differences indicated statistically significant. The mean value of lower VCA was 0.60° smaller than the mean value of upper VCA in normal volunteers. The mean value of the lower VCA was 0.58° larger than the mean value of the upper VCA in DDH patients. Conclusions Compared to X-ray, 3D reconstruction technology is more accurate without conventional limitations. The lower VCA of DDH patients should be regarded as the femoral intramedullary guide angle in TKA, especially for patients with femoral deformities.

Inflammatory Response of Articular Cartilage to Femoroacetabular Impingement in the Hip

Background: Femoroacetabular impingement (FAI) has been proposed as an etiologic factor in up to 50% of hips with osteoarthritis (OA). Inflammation is thought to be one of the main initiators of OA, yet little is known about the origin of intra-articular inflammation in FAI hips. Hypothesis: Articular cartilage from the impingement zone of patients with FAI has high levels of inflammation, reflecting initial inflammatory process in the hip. Study Design: Controlled laboratory study. Methods: Head-neck cartilage samples were obtained from patients with cam FAI (cam FAI, early FAI; n = 15), advanced OA secondary to cam FAI (FAI OA, late FAI; n = 15), and advanced OA secondary to developmental dysplasia of the hip (DDH OA, no impingement; n = 15). Cartilage procured from young adult donors (n = 7) served as control. Safranin O–stained sections were assessed for cartilage abnormality. Tissue viability was detected by TUNEL assay. Immunostaining of interleukin 1β (IL-1β), catabolic markers (matrix metalloproteinase 13 [MMP-13], a disintegrin and metalloproteinase with thrombospondin motif 4 [ADAMTS-4], aggrecan antibody to C-terminal neoepitope [NITEGE]), and an anabolic marker (type II collagen [COL2]) was performed to evaluate molecular inflammation and metabolic activity. The average percentage of immunopositive cells from the total cell count was calculated. Kruskal-Wallis test followed by Steel-Dwass post hoc test was used for multiple comparisons. Results: Microscopic osteoarthritic changes were more prevalent in cartilage of cam FAI and FAI OA groups compared with DDH OA and control groups. Cartilage in cam FAI and FAI OA groups, versus the DDH group, had higher expression of inflammatory molecules IL-1β (69.7% ± 18.1% and 72.5% ± 13.2% vs 32.7% ± 14.4%, respectively), MMP-13 (79.6% ± 12.6% and 71.4% ± 18.8% vs 38. 5% ± 13.3%), ADAMTS-4 (83.9% ± 12.2% and 82.6% ± 12.5% vs 45.7% ± 15.5%), and COL2 (93.6% ± 3.9% and 92.5% ± 5.8% vs 53.3% ± 21.0%) (P < .001). Expression of NITEGE was similar among groups (cam FAI, 89.7% ± 7.7%; FAI OA, 95.7% ± 4.7%; DDH OA, 93.9% ± 5.2%; P = .0742). The control group had minimal expression of inflammatory markers. Inflammatory markers were expressed in all cartilage zones of early and late FAI but only in the superficial zone of the no impingement group. Conclusion: Cartilage from the impingement zone in FAI is associated with a high expression of inflammatory markers, extending throughout all cartilage zones. Clinical Relevance: Inflammation associated with FAI likely has a deleterious effect on joint homeostasis. Further clinical and translational studies are warranted to assess whether and how surgical treatment of FAI reduces molecular inflammation.

Long-term results of custom-made femoral stems

The progress of 3D imaging and manufacturing of implants has made it possible to achieve a custom-made concept in THA. The custom-made cementless femoral stem provides optimal implant stability combined with restoration of the native hip mechanics. The purpose of this study was to evaluate the long-term survivorship of custom-made hip femoral stems in two populations of patients undergoing THA: patients under 50years old (young patients group) and patients with high-grade developmental dysplasia of the hip (DDH group). Aseries of 232 primary custom-made cementless THA stems were retrospectively evaluated in patients less than 50 years old at the time of surgery and at follow-up after an average of 20years. Asecond series of 26custom-made cementless stem THAs for late DDH (21patients) including only Crowe gradeIII and gradeIV were also retrospectively evaluated with an average follow-up of 16years. The clinical and radiological evaluations were performed preoperatively and at yearly intervals. For the young patient group, the follow-up ranged from 14to 27years. The HHS and the Merle D'Aubigne-Postel score significantly improved from preoperatively to amean of 94.1 (range 48-100) and 15.9 (range 9-18), respectively. Taking stem revision for aseptic loosening as an endpoint, survivorship was 96.8% at 20years (95% confidence interval, CI 95.1-98.5). For the DDH group, the follow-up ranged from 10 to 22years. The mean HHS increased significantly from preoperative 49 ± 22points to the most recent follow-up examination with 8613points and survivorship was 96.1% (95% CI, 92.7-99.9). Custom-made femoral stems provide good functional outcome and long-term survivorship in two specific populations of patients undergoing THAs: patients under 50years old with high expectations and patients with high-grade DDH.

Different subchondral trabecular bone microstructure and biomechanical properties between developmental dysplasia of the hip and primary osteoarthritis

ObjectiveDevelopmental dysplasia of the hip (DDH) is recognized as a frequent cause of secondary osteoarthritis (OA). The purpose in this study was to compare structural and biomechanical properties of subchondral trabecular bone ​and its relationship with cartilage damage between patients with DDH and patients with primary hip OA. MethodsForty-three femoral head specimens obtained from patients who underwent total hip arthroplasty [DDH, n ​= ​17; primary OA, n ​= ​16; and normal control (NC), n ​= ​10] were scanned by microcomputed tomography and analyzed by individual trabecula segmentation to obtain the microstructural types of subchondral trabecular bone. The biomechanical properties were analyzed by micro–finite element analysis, and cartilage damage was evaluated by histology. The linear regression analysis was used to indicate the association between microstructures, biomechanical property, and articular cartilage. ResultsThe DDH group showed the lowest total bone volume fractions (BV/TV) and plate BV/TV in the three groups (p ​< ​0.05). There were also different discrepancies between the three groups in plate/rod trabecular number, plate/rod trabecular thickness, trabecular plate surface area/trabecular rod length, and junction density with different modes (plate–plate, rod–rod, and plate–rod junction density). The micro–finite element analysis, histology, and linear regression revealed that the subchondral trabecular bone in the DDH group had inferior biomechanical properties ​and cartilage damage of patients with DDH was more serious with different subchondral trabecular bone microstructures. ConclusionOur findings detected deteriorating subchondral trabecular bone microstructures in patients with DDH. The mass and type of subchondral trabecular bone play a key role in mechanical properties in DDH, which might be related to cartilage damage. The translational potential of this articleOur findings suggested that changes of subchondral trabecular bone play a critical role ​in DDH progression and that the improvement on subchondral trabecular bone may be a sensitive and promising way in treatment of DDH.

Effects of shooting position on X-ray evaluation index of developmental hip dysplasia

Objective To explore the impacts of the imaging positions on the sagittal tilt of the pelvis and the imaging parameters of the hip joint. Methods From December 2015 to October 2016, a total of 78 female DDH patients (DDH group) who received Bernese periarticular osteotomy were enrolled, aged 28.41±9.91 years (range 18-49 years) with 135 hips. There were 21 cases on one side and 57 cases on both sides. Another 26 female volunteers without spinal and hip disease were enrolled as the control group, aged 23.54±5.58 years (range 18-49 years) with 52 hips. X-ray films of the anterior and posterior pelvis were performed in both groups. The pelvic sagittal tilt was evaluated by measurement (pubic symphysis to sacrococcygeal distance, PSSC), with lateral center-edge angle of Wiberg (LCEA), Tonnis angle (TA), and Sharp angle (angle of Sharp, SA) assessed the degree of hip dysplasia and assessed the horizontal positional relationship between the femoral head and the acetabulum using tear drop distance (TD). All data were measured twice by two measurers independently. The correlation between hip parameters and X-ray position was analyzed. Results The average PSSC in the supine and standing positions of the control group were 53.73±16.22 mm and 36.45±14.21 mm, respectively with significant difference-17.28±8.07 mm (t=-10.913, P=0.000). The PSSC of the supine and standing positions of the DDH group were 56.76±13.54 mm and 48.62±15.44 mm, respectively with significant difference-8.13±13.02 mm (t=-5.516, P=0.000). The PSSC of the standing DDH group was larger than that in the control group. There was no significant difference in the PSSC between the two groups in the supine position. Furthermore, there were no significant difference in the supine and standing PSSC between the unilateral and bilateral DDH patients (P>0.05). In the control group, the hip in supine and standing position, LCEA averaged 30.33°±4.69° and 29.70°±3.83° (P>0.05), and TA averaged 4.05°±3.51° and 4.36°±3.07° (P>0.05), respectively. SA averaged 40.53°±4.34° and 41.79°±3.16° (P>0.05), and TD averaged 6.80±0.98 mm and 6.65±1.30 mm (P>0.05), respectively. In the DDH group, the hip in supine and standing positions, LCEA averaged 3.07°±12.07° and 1.69°±12.11° (P 0.05), respectively. SA averaged 48.01°±4.68° and 48.49°±4.74° (P>0.05), respectively, and TD averaged 10.51±3.51 mm and 10.93±4.23 mm (P>0.05), respectively. Conclusion From supine to standing, the pelvis backward is the main trend in sagittal plane. In standing, the pelvis of female DDH patients is forward contrast with normal women. There was no difference in pelvic tilt between unilateral and bilateral DDH patients. Female DDH patients from the supine to standing, hip coverage decreased, while the femoral head appeared horizontally outward. The hip joint of DDH patients is unstable. Key words: Hip dislocation, congenital; Pelvis; Photogrammetry; Osteotomy

Pattern of Inflammatory Molecules in Cartilage of the Impingement Zone in FAI Hips Suggests Origin of Hip Degeneration

Objectives: Femoroacetabular impingement (FAI) is considered a common cause of articular cartilage damage and early hip osteoarthritis (OA) in the young-adult patients. Molecular inflammation is believed to be one of the main initiators of hip OA. Matrix metalloproteinase (MMP)-13 and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4 are known to function as extracellular matrix degrading enzymes in OA joints and have been shown to increase during the process of OA onset. Interleukin (IL)-1β is considered one of the key cytokines involved in the pathogenesis of OA. The aim of this study is to characterize inflammation and early OA pathways in cartilage from the head-neck impingement area in patients with symptomatic FAI cam. Methods: Cartilage samples were obtained in the head neck-junction area from 37 patients undergoing hip surgery between May 2017 and July 2018. Nine patients had a clinical diagnosis of FAI cam (FAI cam) and 15 patients presented advanced OA secondary to FAI cam (OA FAI). These cartilage samples were compared to cartilage samples obtained from similar head neck-junction area from 13 patients with advanced OA secondary to developmental dysplasia of the hip with no impingement (OA DDH). Radiographically, the α-angle was utilized to confirm hip impingement. All histological sections were stained with Safranin-O to assess cartilage degeneration. OARSI grade and Mankin score were used to quantify degenerative OA changes. Immunohistochemistry was performed for IL-1β, MMP-13 and ADAMTS-4. Quantification of immunopositive cells was performed in a blinded fashion. One-way analysis of variance with Tukey’s post hoc test was applied to analyze differences between three groups. Results: FAI cam patients were significantly younger than OA FAI patients (p&lt;0.001) and OA DDH patients (p=0.0461) (Table 1). The average α-angle was significantly higher in the FAI cam and OA FAI groups than the OA DDH group (p&lt;0.001). Cartilage samples from the FAI cam and the OA FAI groups showed degenerative changes. The average OARSI grade was significantly (p&lt;0.01) higher in FAI cam (4.0±0.4) and OA FAI (3.6±0.9) compared to OA DDH (2.2±0.6). The average Mankin score was significantly (p&lt;0.001) higher in FAI cam (7.6±1.2) and OA FAI (6.9±1.8) than OA DDH (4.1±0.7). IL-1β was expressed in cartilage samples from all groups, although the pattern varied.IL-1β was expressed mainly in the superficial layer in the OA DDH group but throughout all cartilage layers in the FAI cam and OA FAI groups. The % immunopositive cells were significantly (p&lt;0.001) higher in FAI cam (58.1±8.9) and OA FAI (71.3±12.4) than OA DDH (28.9±6.3). Similar pattern of distribution was observed for MMP-13 (72.7±11.3, 70.2±18.2 vs 38.0±8.6; p&lt;0.001, p&lt;0.001) and ADAMTS-4 (73.1±7.3, 82.0±12.3 vs 45.3±12.7; p&lt;0.001, p&lt;0.001) (Figure 1). Conclusion: Osteoarthritic changes are evident in the cartilage from the head-neck area of patients with FAI cam morphology. Inflammatory molecules were evident in both early and late stages of hip impingement, suggesting the head-neck impingement area is a potential mediator of inflammation and joint degeneration. [Figure: see text][Table: see text]

The Demographics of Canine Hip Dysplasia in the United States and Canada.

Canine hip dysplasia (CHD) is a common problem in veterinary medicine. We report the demographics of CHD using the entire hip dysplasia registry from the Orthopedic Foundation for Animals, analyzing differences by breed, sex, laterality, seasonal variation in birth, and latitude. There were 921,046 unique records. Each dog was classified using the American Kennel Club (AKC) and Fédération Cynologique Internationale (FCI) systems. Statistical analysis was performed with bivariate and logistic regression procedures. The overall CHD prevalence was 15.56%. The OR for CHD was higher in females (1.05), those born in spring (1.14) and winter (1.13), and those in more southern latitudes (OR 2.12). Within AKC groups, working dogs had the highest risk of CHD (OR 1.882) with hounds being the reference group. Within FCI groups, the pinscher/molossoid group had the highest risk of CHD (OR 4.168) with sighthounds being the reference group. The similarities between CHD and DDH are striking. Within DDH there are two different types, the typical infantile DDH and the late onset adolescent/adult acetabular dysplasia, with different demographics; the demographics of CHD are more similar to the later onset DDH group. Comparative studies of both disorders should lead to a better understanding of both CHD and DDH.

A short-stem hip implant with metaphyseal anchorage in patients with developmental dysplasia of the hip.

Short-stem implants are routinely used for total hip arthroplasty in younger patients that are more likely to have secondary osteoarthritis than older patients. To investigate the applicability of short-stem hip implants for secondary osteoarthritis due to developmental dysplasia of the hip. This study analyzed the clinical and radiological results of patients with developmental dysplasia of the hip (DDH, 58 hips) and compared them to those of patients with primary osteoarthritis (POA, 59 hips) treated with the metaphyseal total hip arthroplasty (Metha®) short stem with metaphyseal fixation. The mean clinical and radiological follow-up periods were 2.9 ± 1.1 years and 3.8 ± 1.9 years, respectively. The mean Harris Hip Score (HHS) significantly increased in both groups over this period (p< 0.0001). The caput-collum-diaphysis (CCD) angle was significantly lower in the POA group prior to surgery and significantly increased in the POA and and decreased in DDH groups, respectively. The preoperative femoral offset was lower in the DDH group and increased significantly after surgery. The Metha® short stem in patients with DDH allows good reconstruction of joint biomechanics with a good clinical outcome.

The Dega Osteotomy: A Versatile Osteotomy in the Treatment of Developmental and Neuromuscular Hip Pathology

The purpose of this study is to evaluate the use of the Dega osteotomy in the treatment of hip pathology resulting from both developmental dysplasia (DDH) and neuromuscular disease (NM). We retrospectively reviewed the results of one surgeon's operative experience with the Dega osteotomy for the treatment of DDH and NM. Forty-four patients (50 hips) with an average length of follow-up of 53 months were identified. The Dega was customized at the time of surgery to provide more anterior or posterior coverage depending on the needs of the individual hip. In all cases, there were no intraoperative complications and all hips were well reduced postoperatively. In the DDH group, there were 22 children (26 hips), who underwent surgery at a mean age of 3.1 years. Thirteen hips had a concomitant open reduction and 4 had a femoral osteotomy. There were 5 complications: 2 femoral head lateralizations, 2 avascular necroses (asymptomatic), and 1 traumatic dislocation. One patient (1 hip) had a reoperation. All patients had unlimited physical activity with no limp with an improvement in the acetabular index from 37 degrees preoperatively to 13 degrees at last follow-up. In the NM group, there were 22 children (24 hips), who underwent surgery at a mean age of 6.3 years. Twenty-three hips had concomitant procedures performed. At an average of 56 months postoperatively, all patients were pain-free. There were 5 complications: 1 graft dislodgement, 1 graft collapse, and 3 femoral head lateralizations. Three patients (3 hips) had a reoperation. Acetabular index improved from 36 degrees preoperatively to 14 degrees, and the migration percentage ranged from 84% to 14%. In this series of Dega osteotomies, one of the largest in the English literature, the osteotomy seems safe and effective in the treatment of both DDH and NM hip disease. The Dega osteotomy is utilitarian, as it may provide increased acetabular coverage anteriorly or posteriorly depending on where it is hinged. Therapeutic study, clinical case series: level IV.