Acetabular Cartilage Research Articles

Preoperative quantitative imaging use in predicting intraoperative decision for hip labral repair versus reconstruction

Abstract Intraoperative assessment of labral quality determines arthroscopic repair versus reconstruction for hip labral tear treatment. T2 mapping technology discriminates between healthy and damaged cartilage. This study investigated if T2 mapping magnetic resonance imaging (MRI) can preoperatively predict labral repair versus reconstruction. This retrospective comparative study included patients with preoperative T2 mapping MRI who underwent hip labral repair or reconstruction at a single institution between March 2021 and February 2023. Three reviewers using Syngo.via recorded average T2 mapping values for the labrum, acetabular cartilage, and femoral cartilage on patients’ sagittal cut. Intraclass correlation values estimated rater agreement of T2 values. T2 means were compared using t-tests. Three Bayesian regression models were created, separately analyzing the labrum, acetabular cartilage, and femoral cartilage mapping values. The 95% credible intervals determined the significance of regression coefficients. A total of 63 operations were included: 14 reconstructions and 49 repairs. Participants were 14- to 50-years-old, with 35 females and 28 males. There was excellent agreement among raters for T2 measurements. There was no significant difference in average T2 values between the repair and reconstruction groups. All three models showed that the odds of labral reconstruction were negatively associated with T2 mapping values, positively associated with age, and increased in males. Preoperative T2 mapping values from the labrum, acetabular, and femoral cartilage are negatively associated with the odds of needing a labral reconstruction. Increased age and being male are associated with increased odds of needing a labral reconstruction. This study will allow further evaluation into other variables that predict labral repair versus reconstruction.

Symptomatic Acetabular Erosion After Hip Hemiarthroplasty: Is It a Major Concern? A Retrospective Analysis of 2477 Hemiarthroplasty Cases

Background/Objectives: Acetabular erosion is a postoperative condition that can occur after hip hemiarthroplasty (HA), potentially leading to pain and requiring conversion to total hip arthroplasty (THA). Given the discrepancy in its incidence and impact in the literature, this study aims to report the incidence of symptomatic acetabular erosion and the subsequent conversion to THA in all HA cases performed in a single health system. Methods: A total of 2477 HA cases had their clinical notes and serial radiographs examined for this retrospective study. Outcome measures included any records of hip or groin pain and conversion to THA that were attributed to acetabular erosion as documented in the clinical notes. Results: Two thousand four hundred and seventy-seven HA cases were reviewed in this study. The mean age for all patients in the study was 81.5 years and the mean follow up was 3.7 years. Out of the 2477 HA cases, only 12 HA cases (0.48%) in 12 patients had data records of chronic hip pain, attributable to acetabular wear in the clinical notes, of variable severity and presentations. The mean duration until the clinical documentation of acetabular wear-induced pain was 25.6 months (range, 1.4–146.4 months), with most symptomatic hip erosion cases presented within the first year (50% presented within the first 6 months) after the index HA surgery. Despite that, only five cases underwent conversion to THA (0.2%) while seven patients received conservative management. Conclusions: In patients older than 65 years of age who are candidates for HA, the incidence of symptomatic hip erosion and the subsequent conversion to THA is low and hence HA remains a viable treatment option. Based on the duration until clinical presentation of acetabular erosion, this study suggests that the state of acetabular cartilage during surgery may influence the development of early acetabular wear in most symptomatic patients. On the other hand, hip hemiarthroplasty is a rare treatment option for displaced femoral neck fractures in patients younger than 65 years of age, and its use in this patient subset depends on conditional and patient-related factors such as the activity level, cognitive function, and medical comorbidities.

A Computer Modeling-Based Target Zone for Transposition Osteotomy of the Acetabulum in Patients with Hip Dysplasia.

This study aimed to determine the acetabular position to optimize hip biomechanics after transposition osteotomy of the acetabulum (TOA), a specific form of periacetabular osteotomy, in patients with hip dysplasia. We created patient-specific finite-element models of 46 patients with hip dysplasia to simulate 12 virtual TOA scenarios: lateral rotation to achieve a lateral center-edge angle (LCEA) of 30°, 35°, and 40° combined with anterior rotation of 0°, 5°, 10°, and 15°. Joint contact pressure (CP) on the acetabular cartilage during a single-leg stance and simulated hip range of motion without osseous impingement were calculated. The optimal acetabular position was defined as satisfying both normal joint CP and the required range of motion for activities of daily living. Multivariable logistic regression analysis was used to identify preoperative morphological predictors of osseous impingement after virtual TOA with adequate acetabular correction. The prevalence of hips in the optimal position was highest (65.2%) at an LCEA of 30°, regardless of the amount of anterior rotation. While the acetabular position minimizing peak CP varied among patients, approximately 80% exhibited normalized peak CP at an LCEA of 30° and 35° with 15° of anterior rotation, which were the 2 most favorable configurations among the 12 simulated scenarios. In this context, the preoperative head-neck offset ratio (HNOR) at the 1:30 clock position (p = 0.018) was an independent predictor of postoperative osseous impingement within the required range of motion. Specifically, an HNOR of <0.14 at the 1:30 clock position predicted limitation of required range of motion after virtual TOA (sensitivity, 57%; specificity, 81%; and area under the receiver operating characteristic curve, 0.70). Acetabular reorientation to an LCEA of between 30° and 35° with an additional 15° of anterior rotation may serve as a biomechanics-based target zone for surgeons performing TOA in most patients with hip dysplasia. However, patients with a reduced HNOR at the 1:30 clock position may experience limited range of motion in activities of daily living postoperatively. This study provides a biomechanics-based target for refining acetabular reorientation strategies during TOA while considering morphological factors that may limit the required range of motion.

Arthroscopic Chondral Nail Fixation for Treating Acetabular Cartilage Delamination Results in Improved Pain Relief at Minimum 2-year Follow-up in Patients with Femoroacetabular Impingement Syndrome: A Propensity-Matched Study

PurposeTo investigate the clinical outcomes following arthroscopic chondral nail fixation for acetabular cartilage delamination (ACD) in patients with femoroacetabular impingement syndrome (FAIS), and the presentation of ACD on MRI at follow-up. MethodsA retrospective review was performed between March 2021 and March 2022 at our institute. Patients undergoing primary hip arthroscopy for FAIS and diagnosed with ACD intraoperatively were included. Exclusion criteria were incomplete data or loss of minimum 2-year follow-up, and concomitant hip conditions including hip osteoarthritis with a Tönnis grade > 1, avascular necrosis, Legg-Calvé-Perthes disease, osteoid osteoma, synovial chondromatosis, pigmented villonodular synovitis, and developmental dysplasia of the hip (DDH). Patients who underwent chondral nail fixation were matched 1:1 with a control cohort of patients who only underwent simple debridement. Preoperative and minimum 2-year postoperative patient-reported outcome (PRO) scores including Visual Analog pain Scale (VAS), modified Harris Hip Score (mHHS), and percentage of achieving minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were collected and compared. MRI was performed preoperatively and at final follow-up to assess ACD. ResultsFifty-eight patients were included in the study (29 patients in each group). Both groups demonstrated improved VAS and mHHS following surgery (all with P < .05). The chondral nail group demonstrated better postoperative VAS (P = .022) compared to the control group, while the postoperative mHHS was comparable between the two groups (P = .852). No significant difference was found in the achievement of MCID between the two groups (all with P > .05). More patients in the chondral nail group achieved PASS of VAS compared to the control group (75.9% vs 48.3%, P = .030). No patient underwent revision surgery or conversion to total hip arthroplasty (THA). The chondral nail group demonstrated significantly higher rate of ACD healing on MRI compared to the control group (P < .001). ConclusionPatients undergoing arthroscopic chondral nail fixation for treating ACD demonstrated significant pain relief, more achievement of PASS of VAS, and higher rate of ACD healing on MRI compared to those undergoing simple debridement. Level of EvidenceLevel III; retrospective cohort study.

Evaluation of the thickness of acetabular cartilage by ultrasound in developmental dysplasia of the hip.

It has been reported that the cartilaginous roof of the acetabulum is thicker in infants with developmental dysplasia of the hip (DDH) than in those with healthy hips. However, there is limited research on the changes in the thickness of acetabular cartilage after follow-up or treatment of DDH. This study aims to report the thickness of acetabular cartilage before and after treatment of DDH. In this prospective study, infants with clinical suspicion of DDH were enrolled in the pediatric outpatient service in our hospital from January 2022 to August 2023. The thickness of acetabular cartilage was measured in the standard coronal plane. Borderline hips (Graf IIa type) were monitored with monthly ultrasound examination until they were classified as normal hips (Graf I type), while dysplastic hips (Graf IIb type or worse) were treated with the Pavlik harness until they were also classified as normal hips in the final ultrasound examination. A total of 592 children [median age, 96 days (interquartile range, 70-142 days); 197 boys] were enrolled in the study. The thickness of acetabular cartilage in dysplastic hips (4.3 ± 1.6 mm) was greater than that in normal hips (3.0 ± .39 mm, P < 0.001) and borderline hips (3.1 ± .57 mm, P < 0.001). In borderline hips, the thickness of acetabular cartilage decreased from 3.1 ± .57 mm in the initial evaluation to 2.9 ± .53 mm in the final follow-up scan (P = 0.01). In dysplastic hips, the thickness of acetabular cartilage decreased from 4.3 ± 1.6 mm in the initial evaluation to 3.5 ± .51 mm after treatment (P = 0.003). The thickness of acetabular cartilage in dysplastic hips after treatment remained greater than that in normal hips (P < 0.0001). The thickness of acetabular cartilage decreased after follow-up or treatment of DDH. Further research is required to determine whether cartilage that remain thicker in dysplastic hips than that in normal hips after treatment should be considered an early indicator of residual acetabular dysplasia.

Assessing hip joint-related structure and patient-reported outcomes in people with Marfan syndrome.

People with Marfan syndrome (MFS) have clinical symptoms of hip pain, but to date, there is limited knowledge about hip-related structural abnormalities in these patients. Therefore, the purpose of this cross-sectional study was to assess hip-related structural abnormalities and patient-reported outcomes (PRO) in a cohort of patients with MFS compared to healthy controls. Nineteen individuals with MFS(17 females, 39.8±11.5 years) and 19 age, sex, and body mass index-matched healthy, asymptomatic individuals (17 females, 36.2±12.5 years)underwent radiographic imaging and unilateral hip MRI. The Scoring Osteoarthritis with MRI (SHOMRI) technique was used to assess hip-related morphological abnormalities between the MFS and control groups. All participants completed the Hip disability and Osteoarthritis Outcome Score (HOOS) to assess hip-related symptoms, pain, and function during activities of daily living (ADL) and quality of life (QOL). The MFS group exhibited higher lateral center edge angles (p < .001). Despite similar severity of femoral cartilage damage (p = 1.0), the MFS group exhibited a higher severity (p = 0.046)of acetabular cartilage degeneration (1.21±1.08) compared to the controls(0.53±1.02). There were no between-group differences in severity of labral pathology, subchondral cysts, or edema. Individuals with MFS also self-reported significantly lower HOOS symptoms (p = 0.003), pain (p = 0.014), ADL (p = 0.028), and QOL (p = 0.014) sub-scores, indicating worse hip-related PRO in MFS. Our study results suggest that individuals with MFS exhibit early signs of acetabular cartilage degeneration and poor hip-related clinical outcomes compared to healthy individuals. Future work should investigate the underlying biomechanical mechanisms associated with hip joint degeneration in the MFS population.

Ligamentum teres lesions are associated with compositional and structural hip cartilage degenerative change: region-specific cartilage degeneration.

To investigate the association between magnetic resonance imaging (MRI)-based ligamentum teres lesions (LTL) and structural hip degeneration. Bilateral 3-T hip MRIs of participants (n = 93 [36 men]; mean age ( ± SD) 51 years ± 15.4) recruited from the community and the orthopedic clinic of a single medical center were included. Clinical and imaging data acquired included hip disability and osteoarthritis outcome scores, semi-quantitative scoring of hip osteoarthritis on MRI (SHOMRI) scores on fluid-sensitive sequences, and cartilage T1ρ/T2 compositional sequences. An MRI-based LTL scoring system, incorporating continuity, thickening, and signal intensity, ranging from 0 (normal) to 4 (complete tear) was constructed. Hip morphological features associated with LTL, based on functional or anatomical relationships to LT, were defined. Relationships between MRI-LT scores and SHOMRI, global/regional cartilage T1ρ/T2, and proposed morphological abnormalities and LTL were explored by mixed effects linear and logistic regression models. In 82 (46.1%) hips, no pain was documented; 118 (63.4%) and 68 (36.6%) hips were graded as KL-grade ≤ 1 and ≥ 2, respectively. Compared to MRI-LT score = 0 (normal), score = 4 (complete tear) revealed significantly worse subchondral bony degenerative changes for bone marrow lesions (SHOMRI-BML) and subchondral cysts (SHOMRI-sc) (p < 0.001, p = 0.015, respectively). Global acetabular T1ρ, femoral T2 were significantly increased for abnormal MRI-LT scores (p-range = 0.005-0.032). Regional analyses revealed significantly increased T1ρ/T2 in central acetabular/increased T2 in off-central femoral regions (p-range = 0.005-0.046). Pulvinar effusion-synovitis, shallow fovea, and foveal osteophytes were significantly associated with abnormal LT MRI findings (p-range = < 0.001-0.044). MRI abnormalities of LT are associated with worse SHOMRI-sc/BML scores, indicative of hip osteoarthritis and higher T1ρ and T2 that differ by region. Pulvinar effusion-synovitis and changes in femoral head morphology are associated with LTL. Abnormal ligamentum teres findings identified via MRI are associated with structural degenerative changes of the hip joint and alterations in acetabular and femoral cartilage compositions show spatial differences in relation to LTL. The clinical significance of common ligamentum teres lesions (LTL) on MRI is not well understood. LTL identified by an MRI-based scoring system is associated with worse biomarkers, indicating more advanced degenerative hip changes. Effusion-synovitis signal at pulvinar, shallow fovea capitis, and foveal osteophytes are associated with LTL on imaging.

DELAYED GADOLINIUM-ENHACED MAGNETIC RESONANCE IMAGING OF CARTILAGE IS A PREDICTOR OF PERIACETABULAR OSTEOTOMY FAILURE IN PATIENTS 40 YEARS AND OLDER

Pelvic osteotomies for hip dysplasia results can be variable and depend on the amount of preexisting arthritis. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a technique designed to measure early arthritis, and could be used to select hips that would benefit from a joint-preserving reconstructive procedure. Our objective was to investigate the role of preoperative dGEMRIC in predicting the success of PAO in patients 40 and above. We hypothesized that patients who failed had lower preoperative dGEMRIC index compared to those who did not.Following IRB approval, patients 40 or older who underwent PAO between 1990–2013 and had preoperative dGEMRIC scan and minimum follow-up of 4 years were identified. Patients with prior hip surgeries or any pathologies were removed leading to a total of 70 patients (Age: 44.2 ± 2.9 years old, BMI: 25.7 ± 4.5 Kg/m2). We only included the first hip undergoing PAO for those with bilateral PAO. Out of 70, 19 had failure defined by the need for total hip replacement or WOMAC pain score of 10 and above within 10 years after index PAO surgery. Articular cartilage was segmented on the 3D pre-operative dGEMRIC scan. The average thickness and dGEMRIC index across the whole articular surface were analyzed.Failed hips had a lower dGEMRIC index by 115 ± 20 ms (P&lt;0.001). All but one failed hips had a dGMERIC index of 400 or less (range: 313 – 479 ms), while all survived hips had a dGMERIC index of greater than 400 (range: 403 – 691 ms). Similar trends were observed when comparing the dGEMRIC index within the 6 subgroups (P&lt;0.01). There were no differences in cartilage thickness (combined femoral head and acetabular cartilage) between the failed and survived hips (p&gt;0.2).Patients with a high dGMERIC index (indicating high GAG content) may have a higher chance of successful outcomes following PAO. Current efforts are underway to develop a multi-modal predictive model to evaluate risk of failure after PAO.

CT Arthrography With Traction in Femoro-Acetabular Impingement: How to Do It?

Computed tomography arthrography (CTA) highly correlates with arthroscopy in detecting labral tears, especially in patients with positive impingement tests. CTA enables the acquisition of isotropic datasets with high spatial resolution within a single acquisition. However, the hip is a close-fitting, congruent, and nearly spherical joint, with relatively thin cartilage. We describe herein a simple and cost-effective method using traction for hip CTA, with axial manual distraction, that helps overcome the usual limitations, by widening the articular joint space and thus better delineating both acetabular and femoral cartilages.

Save the subchondral bone plate: Debridement versus bone marrow stimulation in acetabular cartilage defects over 60 months of follow-up.

Bone marrow stimulation is a common treatment for full-thickness cartilage defects in the hip joint. However, common procedures may result in poor fibrous repair tissue and changes to the subchondral anatomy. This study investigated the clinical outcome of a cohort of International Cartilage Repair Society (ICRS) grades 3 and 4 cartilage defects treated with bone marrow stimulation compared to those who received simple debridement/chondroplasty. In this retrospective registry study, 236 patients with uni-focal acetabular chondral lesions of the hip up to 400 mm² (mean 177.4 ± 113.4 mm²) and of ICRS grade ≥3 with follow-up of at least 12 months (mean 33.2 ± 15.3 months) were included. Eighty-one patients underwent bone marrow stimulation (microfracture: n = 44, abrasion: n = 37) besides treatment of the underlying pathology, 155 patients underwent defect debridement/chondroplasty. The patient-reported outcome was measured using the International Hip Outcome Tool 33 (iHOT33) score and the Visual Analogue Scale (VAS) for pain. iHOT33 and VAS both improved highly statistically significantly (p < 0.001) in the debridement group after 6, 12, 24, 36 and 60 months compared to the preoperative scores, whereas iHOT33 and VAS after microfracture or abrasion did not show statistically significant changes over time. Twenty-four and sixty months postsurgery the debridement group revealed significant higher scores in the iHOT33 compared to the bone marrow stimulation groups. Patients with chondral lesions of the hip ≤400 mm2 sustainably benefit from arthroscopic debridement under preservation of the subchondral bone plate in terms of functional outcome and pain in contrast to patients treated with bone marrow stimulation. These findings discourage the currently recommended use of microfracture in the hip joint. Level III.

The clinical application value of 3.0T magnetic resonance T2 mapping imaging in evaluating the degree of acetabular cartilage degeneration in joint replacement surgery running title: MRI and acetabular cartilage degeneration

BackgroundTo explore and compare the values of 3.0T magnetic resonance imaging (MRI) T2 mapping in evaluating the degree of acetabular cartilage degeneration in hip replacement surgery.MethodsA total of 26 elderly patients with femoral neck fractures who were scanned in 3.0T MRI T2 mapping quantification technique were included. Basing on MRI images, the degree of acetabular cartilage degeneration was classified into Grade 0, 1, 2, 3 and 4, according to the International Cartilage Repair Society (ICRS) scores. In addition, 8 healthy volunteers were included for control group.ResultsBy comparison with health population, T2 relaxation values in the anterior, superior, and posterior regions of acetabular cartilage in patients with femoral neck fracture were obviously increased (P < 0.001). Among the patients with femoral neck fractures, there were 16 hip joint with Grade 1–2 (mild degeneration subgroup) and 10 hip joints with Grade 3–4 (severe degeneration subgroup), accounting for 61.54% and 38.46%, respectively. Additionally, T2 relaxation values in the anterior and superior bands of articular cartilage were positively related to the MRI-based grading (P < 0.05); while there was no significant difference of T2 relaxation values in the posterior areas of articular cartilage between severe degeneration subgroup and mild degeneration subgroup (P > 0.05). Importantly, acetabular cartilage degeneration can be detected through signal changes of T2 mapping pseudo-color images.Conclusion3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration, which can effectively monitor the disease course.

Association of Patient Satisfaction 2 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome With Minimum 10-Year Patient-Reported Outcomes and Survivorship

Background: Previous studies have shown that short-term outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) predict midterm outcomes, but a limited number of studies have evaluated whether short-term outcomes predict long-term outcomes and survivorship. Purpose: To evaluate whether achieving clinically significant outcomes at 2 years after hip arthroscopy for FAIS can predict patient-reported outcomes (PROs) and survivorship at 10 years. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent primary hip arthroscopy for FAIS between June 2012 and December 2012 with a minimum 10-year follow-up were identified. Using previously established thresholds, we classified patients who achieved the 2-year Patient Acceptable Symptom State (PASS) for the visual analog scale (VAS) for satisfaction as the high satisfaction group and patients who did not as the low satisfaction group. Minimum 10-year PROs were then compared between the groups, including scores for the Hip Outcome Score (HOS)–Activities of Daily Living and –Sports Specific, the modified Harris Hip Score, the VAS for pain, and the VAS for satisfaction. Reoperation-free survivorship was compared. Results: Of 120 eligible consecutive patients, 85 patients were included (70.8% follow-up rate), of whom 61.2% were female. The mean age was 34.0 ± 12.8 years, and the mean body mass index was 25.4 ± 4.6. Of the 85 patients, 29 (34.1%) did not achieve PASS for the VAS for satisfaction at 2 years postoperatively compared with 56 (65.9%) who did. The low satisfaction group had significantly worse acetabular chondral grades at the time of surgery (P = .008). At minimum 10-year follow-up, the high satisfaction group showed significantly better HOS-Activities of Daily Living, HOS-Sports Specific, modified Harris Hip Score, VAS pain, and VAS satisfaction scores (P≤ .031). Compared with the low satisfaction group, the high satisfaction group had a significantly lower rate of secondary surgery (1.8% vs 24.1%, respectively; P = .002). Conclusion: Patients who achieved PASS for the VAS for satisfaction at 2 years after hip arthroscopy demonstrated superior minimum 10-year outcomes compared with patients who did not, including greater PRO scores and a higher survivorship rate. The high satisfaction group had lower grade acetabular cartilage damage at the time of surgery compared with those who did not achieve PASS for the VAS for satisfaction at 2 years.

Association Between Severity of Chondrolabral Junction Breakdown and Functional Outcomes After Hip Arthroscopy for Acetabular Labral Tears

Background: Despite focus on surgical preservation of the chondrolabral junction (CLJ), the transition zone between the acetabular cartilage and labrum, the association between severity of CLJ breakdown and functional outcomes after hip arthroscopy remains unexplored. Purpose: To assess the influence of CLJ breakdown on patient-reported outcome measures (PROMs) at a 24-month follow-up after hip arthroscopy for symptomatic labral tears. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review of prospectively collected data was conducted to identify patients ≥18 years of age with a minimum 24-month follow-up who underwent hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears secondary to femoroacetabular impingement. The Beck classification of transition zone cartilage was used to grade CLJ damage; patients with grades 0 to 2 were stratified into the mild CLJ damage cohort, and those with grades 3 and 4 were stratified into the severe CLJ damage cohort. PROMs were collected at baseline and at 3, 6, 12 months, and annually thereafter postoperatively. Linear mixed-effects models were used to compare PROMs. Rates of achieving clinically meaningful thresholds and subsequent surgery rates were also compared. Results: In total, 198 patients met the inclusion criteria, with a mean follow-up of 3.54 ± 1.26 years. A total of 95 patients with severe CLJ damage (mean age, 34.9 ± 10.5 years) were compared with 103 patients with mild CLJ damage (mean age, 38.2 ± 11.9 years). Hip Outcome Score–Activities of Daily Living (HOS-ADL), Non-Arthritic Hip Score (NAHS), and visual analog score for pain were inferior in the severe CLJ group at enrollment and all follow-up time points (P≤ .05). However, patients with severe CLJ breakdown exhibited greater improvements in HOS-ADL and NAHS at the 24-month follow-up and achieved clinically meaningful thresholds at equivalent rates to patients with mild CLJ breakdown. Subsequent surgery rates were 6.8% and 12.6% in patients with mild versus severe CLJ damage, respectively (P = .250). Conclusion: Severe CLJ breakdown is associated with increased pain and decreased functional level preoperatively and up to 24 months after hip arthroscopy. Despite this, patients with severe CLJ breakdown experienced greater improvements in functional outcomes at a 24-month follow-up and achieved clinical thresholds at similar rates to patients with mild CLJ damage. Thus, while worse baseline pain and functional levels may indicate severe CLJ breakdown, these patients still benefit substantially from hip arthroscopy.

Risk factors for avascular necrosis of the femoral head after developmental hip dislocation reduction surgery and construction of Nomogram prediction model

BackgroundTo analyze the risk factors for the development of avascular necrosis (AVN) of the femoral head after reduction surgery in children with developmental hip dysplasia (DDH), and to establish a prediction nomogram.MethodsThe clinical data of 134 children with DDH (169 hips) treated with closure reduction or open reduction from December 2016 to December 2019 were retrospectively analyzed. Independent risk factors for AVN after DDH reduction being combined with cast external immobilization were determined by univariate analysis and multivariate logistic regression and used to generate nomograms predicting the occurrence of AVN.ResultsA total of 169 hip joints in 134 children met the inclusion criteria, with a mean age at surgery of 10.7 ± 4.56 months (range: 4–22 months) and a mean follow-up duration of 38.32 ± 27.00 months (range: 12–94 months). AVN developed in 42 hip joints (24.9%); univariate analysis showed that the International Hip Dysplasia Institute (IHDI) grade, preoperative development of the femoral head ossification nucleus, cartilage acetabular index, femoral head to acetabular Y-shaped cartilage distance, residual acetabular dysplasia, acetabular abduction angle exceeding 60°, and the final follow-up acetabular index (AI) were associated with the development of AVN (P < 0.05). Multivariate logistic regression analysis showed that the preoperative IHDI grade, development of the femoral head ossification nucleus, acetabular abduction angle exceeding 60°, and the final follow-up AI were independent risk factors for AVN development (P < 0.05). Internal validation of the Nomogram prediction model showed a consistency index of 0.833.ConclusionPreoperative IHDI grade, preoperative development of the femoral head ossification nucleus, final AI, and acetabular abduction angle exceeding 60° are risk factors for AVN development. This study successfully constructed a Nomogram prediction model for AVN after casting surgery for DDH that can predict the occurrence of AVN after casting surgery for DDH.

The Otto Aufranc Award: Does Hip Arthroscopy at the Time of Periacetabular Osteotomy Improve the Clinical Outcome for the Treatment of Hip Dysplasia? A Multicenter Randomized Clinical Trial

BackgroundA periacetabular osteotomy (PAO) is often sufficient to treat the symptoms and improve quality of life for symptomatic hip dysplasia. However, acetabular cartilage and labral pathologies are very commonly present, and there is a lack of evidence examining the benefits of adjunct arthroscopy to treat these. The goal of this study was to compare the clinical outcome of patients undergoing PAO with and without arthroscopy, with the primary end point being the International Hip Outcome Tool-33 at 1 year. MethodsIn a multicenter study, 203 patients who had symptomatic hip dysplasia were randomized: 97 patients undergoing an isolated PAO (mean age 27 years [range, 16 to 44]; mean body mass index of 25.1 [range, 18.3 to 37.2]; 86% women) and 91 patients undergoing PAO who had an arthroscopy (mean age 27 years [range, 16 to 49]; mean body mass index of 25.1 [17.5 to 25.1]; 90% women). ResultsAt a mean follow-up of 2.3 years (range, 1 to 5), all patients exhibited improvements in their functional score, with no significant differences between PAO plus arthroscopy versus PAO alone at 12 months postsurgery on all scores: preoperative International Hip Outcome Tool-33 score of 31.2 (standard deviation [SD] 16.0) versus 36.4 (SD 15.9), and 12 months postoperative score of 72.4 (SD 23.4) versus 73.7 (SD 22.6). The preoperative Hip disability and Osteoarthritis Outcome pain score was 60.3 (SD 19.6) versus 66.1 (SD 20.0) and 12 months postoperative 88.2 (SD 15.8) versus 88.4 (SD 18.3). The mean preoperative physical health Patient-Reported Outcomes Measurement Information System score was 42.5 (SD 8.0) versus 44.2 (SD 8.8) and 12 months postoperative 48.7 (SD 8.5) versus 52.0 (SD 10.6). There were 4 patients with PAO without arthroscopy who required an arthroscopy later to resolve persistent symptoms, and 1 patient from the PAO plus arthroscopy group required an additional arthroscopy. ConclusionsThis randomized controlled trial has failed to show any significant clinical benefit in performing hip arthroscopy at the time of the PAO at 1-year follow-up. Longer follow-up will be required to determine if hip arthroscopy provides added value to a PAO for symptomatic hip dysplasia.

Comparison of 3T MR arthrography and 3T MRI in intra-articular hip pathology: a cost-analysis.

MR arthrography (MRA) has previously been the radiological gold standard for investigating labral and chondral lesions of the hip joint. In recent years, 3T MRI has demonstrated comparable accuracy, being adopted as the first-line imaging investigation in many institutions. We compare the associated increased cost and radiation dose of the fluoroscopic component of the MRA compared to MRI. In this retrospective review over 2years, 120 patients (mean age 27.3years ± 13.2, range 8-67) underwent 3T MRA or non-contrast 3T MRI. Three musculoskeletal radiologists reported the data independently. Primary objectives included cost-comparison between each and radiation dose of the fluoroscopic component of the MRA. Secondary objectives included comparing detection of pathology involving the acetabular labrum, femoral cartilage, and acetabular cartilage. Then, 58 (48%) underwent 3T MRA and 62 (52%) patients underwent 3T MRI. The added cost of the fluoroscopic injection prior to MRA was €116.31/patient, equating to €7211.22 savings/year. MRA was associated with a small radiation dose of 0.003mSv. Transitioning from 3T MRA to 3T MRI in the investigation of intra-articular hip pathology increases cost savings and reduces radiation dose.

Porcine computational modeling to investigate developmental dysplasia of the hip.

While it is well-established that early detection and initiation of treatment of developmental dysplasia of the hip (DDH) is crucial to successful clinical outcomes, research on the mechanics of the hip joint during healthy and pathological hip development in infants is limited. Quantification of mechanical behavior in both the healthy and dysplastic developing joints may provide insight into the causes of DDHand facilitate innovation in treatment options. In this study, subject-specific three-dimensional finite element models of two pigs were developed: one healthy pig and one pig with induced dysplasia in the right hindlimb. The objectives of this study were: (1) to characterize mechanical behavior in the acetabular articular cartilage during a normal walking cycle by analyzing six metrics: contact pressure, contact area, strain energy density, von Mises stress, principal stress, and principal strain; and (2) to quantify the effect on joint mechanics of three anatomic abnormalities previously identified as related to DDH: variation in acetabular coverage, morphological changes in the femoral head, and changes in the articular cartilage. All metrics, except the contact area, were elevated in the dysplastic joint. Morphological changes in the femoral head were determined to be the most significant factors in elevating contact pressure in the articular cartilage, while the effects of acetabular coverage and changes in the articular cartilage were less significant. The quantification of the pathomechanics of DDH in this study can help identify key mechanical factors that restore normal hip development and can lead to mechanics-driven treatment options.

Specificities in the Structure of the Cartilage of Patients with Advanced Stages of Developmental Dysplasia of the Hip.

Developmental dysplasia of the hip (DDH) presents varying degrees of femoral head dislocation, with severe cases leading to the formation of a new articular surface on the external side of the iliac bone-the neoacetabulum. Despite conventional understanding suggesting otherwise, a tissue resembling hyaline cartilage is found in the neoacetabulum and acetabulum of Crowe III and IV patients, indicating a potential for hyaline cartilage development without mechanical pressure. To test this theory, acetabular and femoral head cartilage obtained from patients with DDH was stained with hematoxylin-eosin and toluidine blue. The immunohistochemical analysis for collagen types II and VI and aggrecan was performed, as well as delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) analysis on a 7.0 T micro-MRI machine. The results obtained from DDH patients were compared to those of the control groups. Hyaline cartilage was found in the neoacetabulum and the acetabulum of patients with DDH. The nature of the tissue was confirmed with both the histological and the MRI analyses. The results of this study proved the presence of hyaline cartilage in patients with DDH at anatomical regions genetically predisposed to be bone tissue and at regions that are not subjected to mechanical stress. This is the first time that the neoacetabular cartilage of patients with advanced stages of DDH has been characterized in detail.

Long-Term Outcomes of Cementless Bipolar Hemiarthroplasty in Young Patients With Osteonecrosis of the Femoral Head: The Impact of Implant Improvements and Preoperative Stage.

Introduction Advancements in bipolar hemiarthroplasty (BHA) implants in the mid-1990s contributed to favorable short-term outcomes for osteonecrosis of the femoral head (ONFH), particularly in cases without acetabular cartilage lesions. Nevertheless, long-term results remain unclear. In this study, we investigated (i) the impact of new-generation BHA implants and (ii) the effect of the preoperative stage on long-term outcomes in young patients with ONFH. Methods The records of consecutive patients with ONFH who underwent cementless BHA were retrospectively reviewed. Patients aged ≥60 years, with <10 years of follow-up, or who underwent acetabular reaming during surgery were excluded. Radiographical and clinical outcomes of patients who received first-generation BHAs and new-generation BHAs (developed after 1998) were compared by stratifying based on preoperative stage 2/3A and 3B/4, according to the Japanese Investigation Committee classification. Results Overall, 50 hips from 39 patients (mean age: 44.6 years; 64% male) with an average follow-up of 18.6 years were included. The frequency of advanced-stage patients was significantly higher in the first-generation BHA group than in the new-generation group. Regarding postoperative outcomes, the first-generation BHA group had higher acetabular erosion grades (p<0.001) and more femoral component loosening than those in the new-generation group (p<0.001). Revisions were performed in eight hips (seven in the first-generation and one in the new-generation BHA groups, p<0.001). In the new-generation BHA group, there were no significant differences in patient background between stage 2/3A and 3B/4 groups, and only one case in the stage 3B/4 group required revision. In the new-generation group, the grade of acetabular erosion was significantly higher for stage 3B/4 than stage 2/3A (p<0.001); other radiographical and clinical outcomes did not differ significantly between stages. Conclusion New-generation BHAs have significantly better implant survival rates for early-stage ONFH than those of first-generation BHAs. These findings indicate that BHA is an acceptable treatment option for early-stage ONFH in young patients.

A new height contouring method for severity prediction in cam-type hip joints: 20 subject-specific cases

Cam-type femoroacetabular impingement syndrome (FAIS) is characterised by a non-spherical continuation of the femoral head into the femoral head-neck junction and is associated with damage to the acetabular cartilage. Diagnostic methods based on cam shape are progressing from 2D radiographic measurements to 3D CT measures, providing greater insight. There is currently no consensus on how to describe the 3D cam lesion shape and subject-specific impingement mechanisms are difficult to determine.A novel 3D ‘contour’ method was used to describe the proximal femur of 20 cam-type hips. Five contours, analogous to height contours on a terrain map, were used to describe the femoral head-neck junction, capturing the progressive height of the cam lesion. From that description, the cam apex (a subject's largest alpha angle), cam extent (spread around the femoral head), cam location (position around the femoral head) and average acetabular coverage, were recorded. A previously developed hip impingement model was used to apply 126 activity-based motions to each subject-specific hip shape and predict impingement occurrence and depth of incursion past the acetabular rim. Correlations between shape measures and impingement occurrence were investigated.The two contours representing the lowest heights (close to the head best fit sphere and 1 mm greater than that) generated cam alpha angle and cam extent measurements which contained the typical clinical measures (Alpha: close to best fit 47°-98°, at 1 mm 45°–77°; Extent: close to best fit 0°–129°, at 1 mm 0°–100°). The remaining contours described the progressive height of the cam lesion up to 4 mm greater than the head radius. Impingement was predicted predominantly from the first 1 mm height of the cam, with only two subjects impinging at a cam height greater than 2 mm. Therefore, it is possible that adequate resection of the first 1 mm of cam height is the most critical in reducing a subject's impingement severity.Impingement occurrence was positively correlated with the cam apex (ρ = 0.84 close to best fit, ρ = 0.70 at 1 mm height), the cam extent (ρ = 0.68 close to best fit, ρ = 0.80 at 1 mm height) and the acetabular coverage (ρ = 0.50, at 1 mm height). However, in line with other work on cam impingement, correlations between any single shape measure and the risk of impingement were not strong enough to be used with confidence as predictive tools. This supports the further development of modelling tools which sufficiently capture the complex shape and can generate an impingement risk metric which accounts for joint motion.