Dysplastic Hips Have Decreased Iliofemoral Ligament Thickness on Coronal Sequences in Magnetic Resonance Imaging: A Matched Cohort Analysis.

PURPOSE: To characterize hip capsule thickness on advanced imaging in patients with and without hip dysplasia and to also evaluate differences in capsular thickness between borderline and true dysplastic patients. METHODS: Patients evaluated by the senior author for concerns of hip pathology from June 2020 to June 2021 were queried and images reviewed to determine dysplasia status by lateral center edge angle (LCEA) ≤ 25 degrees. A group of non-dysplastic patients was identified and matched for age, sex, and body mass index (BMI). Hip capsular thickness was quantified using MRI. A sub-analysis was conducted to compare true dysplastic patients (LCEA < 20°) to borderline dysplastic patients (LCEAs between 20 - 25°). Analysis included independent samples t-tests, Chi-square tests, and multivariable regression. RESULTS: Eighty total patients were included, with a mean age of 31.8 ± 11.7 years, a mean BMI of 26.6 ± 6.5 points, and 70% (56) female patients. Dysplastic patients had a mean LCEA of 19.8 ± 4.3 degrees. Dysplastic individuals had decreased capsular thickness compared to their non-dysplastic controls (2.75 ± 0.96 vs 3.52 ± 1.22 mm, p = 0.003). Multivariable regression showed decreased capsular thickness associated with decreased LCEAs (ß = 2.804, R = 0.432, p<0.001) and dysplasia (ß = -0.709, R2 = 0.056, p = 0.004). Results of a sub-analysis of the dysplastic group examining differences between accepted definitions of borderline dysplasia and true dysplasia showed no significant differences in capsular thickness between the two groups (p = 0.379). CONCLUSIONS: Patients with hip dysplasia were found to have thinner iliofemoral ligaments in the coronal plane on magnetic resonance imaging on magnetic resonance imaging. Further investigation is needed to evaluate any potential implications with hip instability given the thinner hip capsule demonstrated in this study.

Superior outcomes after arthroscopic treatment of femoroacetabular impingement and labral tears with closed versus open capsule.

PURPOSE: The purpose of the study was the clinical evaluation of the capsular management with arthroscopic treatment of femoroacetabular impingement and labral tears by comparing the functional outcomes of closed versus open capsule. METHODS: Patients with a median age of 38 years (18-55), clinical and radiological features of FAI and/or labral tear, and non-arthritic non-dysplastic hips were selected for arthroscopic treatment. Capsulotomy was performed primarily as an interportal section, then a distal extension preserving the zona orbicularis was added. The study compared two matched groups: patients with open capsule versus patients with closed capsule. Clinical outcomes were assessed by Non-Arthritic Hip Score, hip outcome scores of daily living activities and sports-specific scales. Scores were collected preoperatively and 6 months, 2 years and 5 years postoperatively. Rate of revision arthroscopy and conversion to total hip arthroplasty were used for comparing groups. Minimal clinically important differences were calculated for both groups. RESULTS: The study included 42 patients in the OC group and 44 patients in the CC group. Significant improvement of postoperative PROMs was recorded in both groups compared to preoperative scores. CC group significantly improved more than the OC group based on NAHS, HOS-ADL and HOS-SSS over all check points except for NAHS and HOS-ADL at 6 months, which were statistically non-significant. A non-significant difference was observed in the percentage of patients who met the MCID for all reported outcome scores at 5 years in both groups. The rate of reoperation was similar in both groups, but with different indications. CONCLUSION: Arthroscopic treatment of FAI and labral repair with complete closure of the hip capsule led to significantly improved functional outcomes after 5 years follow-up compared with open capsule. Closed capsule can provide greater improvement in the sports-specific outcomes at early follow-up. Controlled capsulotomy limited by zona orbicularis did not produce instability at any postoperative stage. Similar proportions of patients achieved minimal clinically important difference, and similar rates of reoperation were reported in both groups. LEVEL OF EVIDENCE: III.

The posterior capsule is distended in dysplastic hips, but the anterior capsule is not.

PURPOSE: In the setting of acetabular dysplasia, the increased translational motion of the femur may damage the labrum and cartilage, as well as stretch the capsule. The purpose of the study was to investigate the relationship between the acetabular coverage and the capsular stiffness by assessing the distension of anterior and posterior joint recesses on the hip computed tomography arthrography. METHODS: One hundred thirty-three patients (138 hips) with a median age of 36 years (range 18-50 years) who received the computed tomography arthrography for evaluation of nonarthritic hip pain in our institute between 2015 and 2017 were retrospectively reviewed. The maximal distance between the anterior/posterior capsule and the anterior femoral head-neck junction/posterior femoral head on the axial imaging of computed tomography arthrography was defined as the width of anterior/posterior joint recess. The width of anterior/posterior joint recess was adjusted with the diameter of the femoral head and was then compared between acetabular dysplasia (lateral center-edge angle < 25°), normal acetabulum (lateral center-edge angle between 25 and 39°), and deep acetabulum (lateral center-edge angle > 39°). In addition, the standard univariate linear regression analysis was used to investigate the relationship between the adjusted width of anterior/posterior joint recess and anterior/posterior coverage of the hip, determined by the anterior/posterior wall index. RESULTS: The adjusted width of posterior joint recess was significantly greater in the acetabular dysplasia group than the normal acetabulum and deep acetabulum groups (p < 0.01 and p = 0.02, respectively). There was no significant difference of the adjusted width of anterior joint recess between the groups (n.s.). The adjusted width of posterior joint recess had a significant but weak negative correlation with the anterior wall index (r = - 0.25, p < 0.001), and no correlation with the posterior wall index (r = - 0.0004, n.s.). There was no significant correlation between the adjusted width of anterior joint recess and the anterior/posterior wall index (r = 0.05, n.s./r = 0.07, n.s.). CONCLUSIONS: The distension of posterior capsule on the computed tomography arthrography was significantly greater in acetabular dysplasia. In addition, there was a significant but weak negative correlation between the distension of posterior capsule and the anterior coverage of the hip. It indicated a looser posterior capsule was observed in a dysplastic hip. The relevance of posterior capsular laxity to clinical outcomes warrants further investigation. Given the fact that the distension of anterior capsule was not significantly higher in acetabular dysplasia, the need of anterior capsular plication in a dysplastic hip should be carefully evaluated. LEVEL OF EVIDENCE: Level III.

Fluoride increases the susceptibility of developmental dysplasia of the hip via increasing capsular laxity triggered by cell apoptosis and oxidative stress in vivo and in vitro.

The etiology of developmental dysplasia of the hip (DDH) is multifactorial, including breech presentation and hip capsular laxity. In particular, hip laxity is the main contributor to DDH by changing the ratio and distribution of collagens. Also, fluoride (F) affects collagens from various tissue besides bone and tooth. To investigate the association of DDH and excessive F intake, we conducted this research in lab on cell and animal model simultaneously. We established animal model of combination of DDH and F toxicity. The incidence of DDH in each group was calculated, and hip capsules were collected for testing histopathological and ultrastructural changes. The primary fibroblasts were further extracted from hip capsule and treated with F. The expression of collagen type I and III was both examined in vivo and in vitro, and the level of oxidative stress and apoptosis was also tested identically. We revealed that the incidence of DDH increased with F concentration. Furthermore, the oxidative stress and apoptosis levels of hip capsules and fibroblasts both increased after F exposure. Therefore, this study shows that excessive F intake increases susceptibility to DDH by altering hip capsular laxity in vivo and in vitro respectively. We believe that F might be a risk factor for DDH by increasing hip laxity induced by triggering fibroblast oxidative stress and apoptosis.

Capsular Management in Direct Anterior Total Hip Arthroplasty: A Randomized, Single-Blind, Controlled Trial.

BACKGROUND: The direct anterior approach (DAA) is a popular approach to total hip arthroplasty (THA). Unlike the posterior approach, the importance of anterior capsular management is unknown. This randomized controlled trial compares capsular repair versus capsulectomy. METHODS: This single-surgeon, single-blinded, parallel-group randomized controlled trial occurred between 2013 and 2016. Patients undergoing unilateral, primary THA for osteoarthritis consented to undergo blinded, simple randomization to anterior capsulotomy with repair or anterior capsulectomy. Primary outcome measures included hip range of motion, hip flexion strength, and pain with seated hip flexion. Secondary outcome measures included surgical time, estimated blood loss, postoperative complications, and hip disability and osteoarthritis outcome score. Data were prospectively collected intraoperatively, six weeks, six months, an average of over 5 years postoperatively. RESULTS: Ninety-eight patients were ultimately enrolled in the trial; 50 received capsulectomy and 48 received capsulotomy. No significant differences were seen in preoperative demographics or in primary or secondary outcomes during this study. No difference was seen in pain at final follow-up at average > 5 years postoperatively. CONCLUSION: This study demonstrates that capsular management in DAA THA does not affect postoperative pain or range of motion. The anterior capsule's role in prosthetic stability after DAA THA remains uncertain, but it does not currently appear that repair provides benefit and may lead to increased surgical time and blood loss. As such, capsular management in DAA THA is at surgeon discretion.

Quantification and correlation of hip capsular volume to demographic and radiographic predictors.

PURPOSE: The purpose of this study was to develop a novel method to quantify hip capsular volume in patients undergoing hip arthroscopic surgery, utilizing magnetic resonance arthrogram (MRA) and to determine whether there are demographic or radiological factors that are associated with capsular volume. METHODS: A retrospective review was performed from 2006 to 2014 of consecutive patients who presented with hip pain and received a hip MRA and plain radiographs. All patients were suspected of soft tissue injury due to underlying femoroacetabular impingement (FAI). A novel technique using Osirix MD for the quantification of capsular and femoral head volumes was described. RESULTS: Ninety-seven patients met the study criteria and were included for analysis. The average total capsular volume (including the femoral head) measured 79.89 ± 20.35 cm(3), average femoral head volume 46.68 ± 12.32 cm(3), and average true capsular volume measured 33.20 ± 12.58 cm(3). Average total capsular:femoral head volume ratio was 1.74 ± 0.27. Significant differences were seen between genders for total capsular volume (P < 0.01), femoral head volume (P < 0.01), and true capsular volume (P < 0.01). Total capsular volume:femoral head ratio was greater for females, but was not statistically significant (n.s.). Femoral head volume significantly correlated with alpha angle (P < 0.01), height (P < 0.01), BMI (P < 0.01), BMI (P = 0.02), and age (P < 0.01). Total capsular volume significantly correlated with height (P < 0.01), BMI (P = 0.01), and age (P < 0.01). Age was also correlated with true capsular volume (P = 0.011). No significant differences in capsular volumes were found between normal and abnormal radiographic measurements. CONCLUSION: The current study describes a reproducible radiographic measurement for hip capsule volumes from MRAs. Only gender was predictive of total capsular volume, femoral head volume, and true capsular volume. There were no macroscopic anatomical differences evident on MRA. This method showed good intra- and inter-observer reliability and can aid in future research regarding hip capsule volumes. This novel technique may potentially allow clinicians a readily available and reliable method to detect large and redundant capsules, a possible predisposition for hip micro-instability. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

Specimen-specific finite element representations of implanted hip capsules.

The hip capsule is a ligamentous structure that contributes to hip stability. This article developed specimen-specific finite element models that replicated internal-external (I-E) laxity for ten implanted hip capsules. Capsule properties were calibrated to minimize root mean square error (RMSE) between model and experimental torques. RMSE across specimens was 1.02 ± 0.21 Nm for I-E laxity and 0.78 ± 0.33 Nm and 1.10 ± 0.48 Nm during anterior and posterior dislocation, respectively. RMSE for the same models with average capsule properties was 2.39 ± 0.68 Nm. Specimen-specific models demonstrated the importance of capsule tensioning in hip stability and have relevance for surgical planning and evaluation of implant designs.

Late post-arthroscopy hip instability. Diagnosis, treatment, and 5-year follow-up: A case report.

INTRODUCTION: Hip instability following arthroscopy is a rare complication with a clinical spectrum ranging from gross dislocation (macro-instability) to micro-instability, characterized by pain and limitation for daily activities. Therefore, it should be considered as a potential differential diagnosis in patients experiencing persistent pain after hip arthroscopy. CASE PRESENTATION: A 41-year-old male presented with a history of anterior hip dislocation and macro-instability symptoms three years post-hip arthroscopy. Magnetic resonance imaging (MRI) revealed a disruption of the anterior hip capsule. The patient initiated physiotherapy and resumed activities, but ten months later, experienced another anterior dislocation. Pain and apprehension during external hip rotation were evident. Three-dimensional computed tomography (CT) indicated irregularities in the anterior and superior margin of the acetabulum, while MRI arthrogram showed a rupture of the anterior capsule and deficiency in the anterior hip ligaments. Open reconstruction of the anterior capsule was performed, resulting in favorable progression over the 5-year follow-up. DISCUSSION: This case highlights post-arthroscopy hip instability with a delayed presentation, possibly linked to chronic anterior capsule deficiency and inadequate acetabular coverage. Primary capsule repair after hip arthroscopy has proven effective in reducing the occurrence of instability symptoms and reoperations. CONCLUSIONS: Post-arthroscopic hip instability may manifest immediately after surgery or several years later. Open reconstruction of the anterior capsule emerges as a successful strategy for addressing this complication, demonstrating satisfactory outcomes in a 5-year follow-up.

Relationship Between Hip Capsular Thickness and Instability After Previous Hip Arthroscopic Surgery: A Matched-Cohort Analysis.

Background: Thinner anterior hip capsules are associated with hip laxity, but there is little known about the impact of capsular thickness on the development of instability after primary hip arthroscopic surgery. Purpose: To investigate the relationship between hip capsular thickness as measured on preoperative magnetic resonance imaging (MRI) and the development of hip instability after hip arthroscopic surgery for femoroacetabular impingement. Study Design: Case-control study; Level of evidence, 3. Methods: We reviewed revision hip arthroscopic procedures performed between January 1, 2019, and May 1, 2021, at a single institution. Inclusion criteria were preoperative MRI/magnetic resonance arthrography, completion of the study traction protocol, and asymmetric distraction between the hips of ≥3 mm on examination under anesthesia. A comparison group of patients treated for femoroacetabular impingement with primary hip arthroscopic surgery who did not develop capsular instability were matched 1:1 to the patients with instability. Superolateral hip capsular thickness was measured on MRI before index surgery. Analysis was conducted using independent-samples t tests and multivariable linear regression. Results: A total of 44 patients were included, with 22 patients each in the instability and no-instability groups. The mean capsular thickness was lower in the patients with hip instability than in those without (1.9 ± 0.6 vs 3.4 ± 1.1 mm, respectively; P < .001). Decreased capsular thickness was significantly associated with hips with instability versus no-instability (ß = -1.468 [95% CI, -2.049 to -0.887]; P < .001). Conclusion: Thinner preoperative hip capsules in the region of the iliofemoral ligament were seen in patients who subsequently underwent revision arthroscopic surgery for hip instability compared to patients who underwent primary hip arthroscopic surgery without subsequent revision. Patients at a higher risk for the development of postoperative hip instability had a superolateral hip capsular thickness of <2 mm.

The Role of the Hip Capsule in Restoring Stability in the Initial Phase of Hip Distraction: An In Vivo Analysis.

Background: The labral suction seal has been shown to provide the majority of resistance in the initial phase of hip distraction. However, the effect of an unrepaired interportal capsulotomy and capsular repair on the initial phase of hip distractive stability in vivo is not well understood. Purpose: To investigate the effect of capsular repair on the initial phase of distractive stability of hip joints in patients with femoroacetabular impingement (FAI) syndrome. Study Design: Controlled laboratory study. Methods: Patients undergoing primary hip arthroscopy for FAI between March and August 2020 were prospectively enrolled. Total joint space was measured on fluoroscopic images at the medial and lateral edges of the sourcil at 12.5-lb (5.7-kg) axial traction intervals (up to 100 lb [45.4 kg]) in 3 capsular states: (1) native capsule, (2) interportal capsulotomy, and (3) capsular repair. Distraction on anteroposterior radiographs was calculated as the difference between total joint space at each traction interval and baseline joint space at 0 lb, normalized to millimeters. The native, capsulotomy, and capsular repair states were compared using Wilcoxon signed-rank and McNemar tests. Results: Included were 36 hips in 35 patients. The median force required to distract ≥3 mm was 75 lb (34.0 kg; 95% CI, 70-80 lb [31.8-36.3 kg]) in both the native and capsular repair states (P = .629), which was significantly greater than the median force required to distract ≥3 mm in the capsulotomy state (50 lb [22.7 kg]; 95% CI, 45-55 lb [20.4-24.9 kg]) (P < .001). The most rapid rates of change in joint space were observed at the traction interval at which hips first achieved ≥3 mm of distraction (n = 33 hips; 92%). Conclusion: The traction force at which hips distracted ≥3 mm was 75 lb (34.0 kg) in both the native capsular and capsular repair states. Significantly less traction force (50 lb [22.7 kg]) distracted hips ≥3 mm in the capsulotomy state. Complete capsular closure after interportal capsulotomy resulted in restoration of initial distractive stability relative to the unrepaired capsulotomy state at time zero after primary hip arthroscopy. Clinical Relevance: This study provides surgeons with an improved understanding of the additional stability to the hip joint from capsular repair after hip arthroscopy for FAI syndrome.

Association Between Anterior Hip Capsule Thickening and Sagittal Pelvic Alignment Among Patients With Developmental Dysplasia of the Hip.

INTRODUCTION: The pathogenesis and pathology of secondary osteoarthritis (OA) of the hip, which is mainly due to developmental dysplasia of the hip (DDH), in Japan are obscure. There are some reports on the thickening of the hip capsule, but the relationship between the thickness of the hip capsule and the pelvic alignment due to hip deformity is not well known. This research investigated whether the capsular thickness of female DDH patients was related to pelvic alignment. METHODS: This single-center cross-sectional study included female patients aged 50-79 years (n=13) who had undergone primary total hip arthroplasty (THA) due to secondary hip OA with a background of DDH. The part of the hip capsule including the iliofemoral ligament was resected and measured directly with a digital caliper. The Sharp angle, center-edge (CE) angle, sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and lumbar lordosis angle (LLA) were measured with an X-ray image to investigate the relationship between the capsular thickness and the pelvic posture. RESULTS: Pearson's correlation coefficient showed a negative correlation between hip capsular thickness and Sharp angle (r=-0.57, p>0.05). No significant correlation was found between the thickness of the hip capsule and the sagittal X-ray parameters including SS, PT, PI, LLA, and CE angle in the coronal plane. CONCLUSION: The thickness of the hip capsule is moderately associated with the Sharp angle on the coronal plane. The results of this study suggest that the thickness of the joint capsule does not necessarily relate to the degenerative process among patients with DDH and the process can be complex to apply two-dimensional postural indices for the explanation.

Can Hip Passive Range of Motion Predict Hip Microinstability? A Comparative Study.

Background: Hip microinstability is an increasingly recognized cause of pain and disability in young adults. It is unknown whether differences in passive hip range of motion (ROM) exist between patients with versus without hip microinstability. Hypothesis: Underlying ligamentous and capsular laxity will result in differences in clinically detectable passive ROM between patients with femoroacetabular impingement (FAI), patients with microinstability, and asymptomatic controls. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A retrospective review of all patients undergoing hip arthroscopy between 2012 and 2018 was conducted. Patients with a diagnosis of isolated microinstability based on intraoperative findings were identified and classified as having isolated FAI, instability, or FAI + instability. Patients without a history of hip injury were included as controls. Range of motion was recorded in the supine position for flexion, internal rotation, and external rotation. Univariate and multivariate analysis was performed on each measurement in isolation as well as combinations of motion to include total rotation arc, flexion + rotation arc, and flexion + 2× rotation arc Models were then created and tested to predict instability status. Results: In total, 263 hips were included: 69 with isolated instability, 50 with FAI, 50 with FAI + instability, and 94 control hips. A higher proportion of patients in the instability and FAI + instability groups were female compared with the FAI and control groups (P < .001). On univariate analysis, differences were found in all groups in all planes of motion (P < .001). Multivariable analysis demonstrated differences in all groups in flexion and flexion + rotation arc. In symptomatic patients, the best performing predictive model for hip microinstability was flexion + rotation arc ≥200° (Akaike information criterion, 132.3; P < .001) with a sensitivity of 68.9%, specificity of 80.0%, positive predictive value of 89.1%, and negative predictive value of 51.9%. Conclusion: Patients with hip microinstability had significantly greater ROM than symptomatic and asymptomatic cohorts without hip microinstability. Symptomatic patients with hip flexion + rotation arc ≥200° were highly likely to have positive intraoperative findings for hip microinstability, whereas instability status was difficult to predict in patients with a flexion + rotation arc of <200°.

What happens in the medium-term to capsule-thickening plasties for iliopsoas impingement after total hip arthroplasty? Evaluation of 14 procedures at 4years' follow-up.

INTRODUCTION: In 2015, we described a capsule-thickening technique via an anterior approach for iliopsoas cup impingement. To our knowledge, medium-term results have not been reported. We therefore retrospectively analyzed all cases in the initial series and those since 2015, to assess this original technique over a longer follow-up: (1) to analyze complications, and (2) to assess functional outcome. HYPOTHESIS: The study hypothesis was that this surgical solution has a success rate sufficient for it to be included in the therapeutic armamentarium for iliopsoas impingement. MATERIAL AND METHOD: Fourteen patients were included. Nine plasties were in first line, 3 after tenotomy, and 2 after cup exchange. The anterior Hueter approach was used, visualizing anterior cup overhang, sometimes associated with penetration of the anterior capsule, and enabling capsule-thickening by a folded Vicryl™ mesh. Functional results were analyzed. RESULTS: At a median 4years' follow-up (IQR: 2-5; range: 1-9), change over baseline in Oxford score was 7 points (p=0.004), median Medical Research Council thigh flexion strength score was 5 (IQR: 5-5), and 50% of patients (7/14) were satisfied or very satisfied. The major complications rate was 7% (1/14), for 1 irrigation of infected hematoma, cured without recurrence; there was also 1 minor case of injury to the lateral cutaneous nerve of the thigh. Forty-three percent of patients (6/14) exhibited a minimal clinically important difference (MCID) and 64% (9/14) a patient-acceptable symptom state (PASS). Median anatomic overhang on anatomic CT transverse slice was 7mm (IQR: 3-8; range: 0-13). Four patients underwent secondary acetabular component exchange; their median overhang was 7.5mm (IQR: 7-8) compared to 5mm (IQR: 2-8) for the other patients (p-value non-calculable). CONCLUSION: This surgical option seems interesting when acetabular overhang is not too great, especially as it does not affect flexion strength. LEVEL OF EVIDENCE: IV.

Capsular Management During Hip Arthroscopy.

PURPOSE OF REVIEW: Hip arthroscopy is widely used for the management of intra-articular pathology and there has been growing interest in strategies for management of the hip capsule during surgery. The hip capsule is an essential structure that provides stability to the joint and it is necessarily violated during procedures that address intra-articular pathology. This article reviews different approaches to capsular management during hip arthroscopy including anatomical considerations for capsulotomy, techniques, clinical outcomes, and the role of routine capsular repair. This article also reviews the concept of hip microinstability and its potential impact on capsular management options as well as iatrogenic complications that can occur as a result of poor capsular management. RECENT FINDINGS: Current research highlights the key functional role of the hip capsule and the importance of preserving its anatomy during surgery. Capsulotomies that involve less tissue violation (periportal and puncture-type approaches) do not appear to require routine capsular repair to achieve good outcomes. Many studies have investigated the role of capsular repair following more extensive capsulotomy types (interportal and T-type), with most authors reporting superior outcomes with routine capsular repair. Strategies for capsular management during hip arthroscopy range from conservative capsulotomy techniques aimed to minimize capsular violation to more extensive capsulotomies with routine capsule closure, all of which have good short- to mid-term outcomes. There is a growing trend towards decreasing iatrogenic capsular tissue injury when possible and fully repairing the capsule when larger capsulotomies are utilized. Future research may reveal that patients with microinstability may require a more specific approach to capsular management.

Evaluation of the Community's Awareness of Developmental Dysplasia of the Hip: A Cross-Sectional Study in Jordan.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a condition where there is an abnormal relationship between the femoral head and acetabulum. DDH is prevalent in Jordan, where late presentations of complicated cases are common due to the absence of a national screening program and cultural behaviors that can exacerbate DDH progression. The study aims to prove that the absence of a nationwide screening program and low awareness of the population about DDH are the primary reasons for the high incidence of late-presenting DDH in Jordan. The study highlights the need for addressing modifiable risk factors like swaddling and correcting common misconceptions such as using multiple diapers as a treatment option. METHODS: The cross-sectional study evaluated the awareness level of DDH among Jordan residents above the age of 18. An online questionnaire was used, containing two sections. The Chi-square test was used to analyze the level of awareness scores according to demographic variables and cultural norms such as tight swaddling and using multiple diapers. The sample was categorized into three groups based on their scores: low awareness (0-4), moderate awareness (5-8), and high awareness (9-12). RESULTS: The study included 1013 participants. The results indicated that 48.9% had moderate awareness, 37.8% had low awareness, and 13.3% had high awareness of DDH. Gender and place of residence had no significant relationship with the level of awareness. However, the majority of participants with high and moderate levels of awareness were in the 25-40 years age group, and healthcare workers had the highest levels of awareness. The study showed that 33.9% of participants gained their knowledge from either relatives or self-experience, while awareness campaigns were the least assessed source of information with only 2.9% of participants getting their information from them. The study also revealed misconceptions regarding DDH, such as the belief that tight swaddling and wearing many diapers reduced the risk of developing DDH. Additionally, about half of the participants were unaware of the presence of screening guidelines for DDH. CONCLUSION: The study underscores the urgent need to establish a national screening program and awareness campaigns to increase knowledge about DDH and prevent late presentations of complicated cases in Jordan. The study findings provide essential information for the development of future DDH campaigns and screening protocols.

Instantaneous Generation of Subject-Specific Finite Element Models of the Hip Capsule.

Subject-specific hip capsule models could offer insights into impingement and dislocation risk when coupled with computer-aided surgery, but model calibration is time-consuming using traditional techniques. This study developed a framework for instantaneously generating subject-specific finite element (FE) capsule representations from regression models trained with a probabilistic approach. A validated FE model of the implanted hip capsule was evaluated probabilistically to generate a training dataset relating capsule geometry and material properties to hip laxity. Multivariate regression models were trained using 90% of trials to predict capsule properties based on hip laxity and attachment site information. The regression models were validated using the remaining 10% of the training set by comparing differences in hip laxity between the original trials and the regression-derived capsules. Root mean square errors (RMSEs) in laxity predictions ranged from 1.8° to 2.3°, depending on the type of laxity used in the training set. The RMSE, when predicting the laxity measured from five cadaveric specimens with total hip arthroplasty, was 4.5°. Model generation time was reduced from days to milliseconds. The results demonstrated the potential of regression-based training to instantaneously generate subject-specific FE models and have implications for integrating subject-specific capsule models into surgical planning software.

Handle With Care: The Anterior Hip Capsule Plays a Key Role in Daily Hip Performance.

Background: Passive energy storage and return has long been recognized as one of the central mechanisms for minimizing the energy cost needed for terrestrial locomotion. Although the iliofemoral ligament (IFL) is the strongest ligament in the body, its potential role in energy-efficient walking remains unexplored. Purpose: To identify the contribution of the IFL to the amount of work performed by the hip muscles for normal, straight-level walking. Study Design: Controlled laboratory study. Methods: Straight-level walking of 50 healthy and injury-free adults was simulated using the AnyBody Modeling System. For each participant, the bone morphology and soft tissue properties were nonuniformly scaled. The superior and inferior parts of the IFL were represented by 2 springs each, and a linear force-strain relation was defined. A parameter study was conducted to account for the uncertainty surrounding the mechanical properties of the IFL. The work required from the gluteus, quadriceps, iliopsoas, and sartorius with and without inclusion of the IFL was calculated. Analysis of variance with subsequent post hoc paired t test was used to test the significance of IFL presence on the required mechanical work. Results: During walking, the strain in the IFL reached a median of 18.7% (95% CI, 8.0%-26.5%), with the largest values obtained at toe-off. With the IFL undamaged and fully operational, the effort required by the hip flexor muscles was reduced by a median of 54% (99% CI, 45%-62%) for the iliopsoas and by a median of 41% (99% CI, 27%-54%) for the sartorius muscles. The inclusion of the IFL did not significantly alter the work required by the gluteus and the quadriceps. Conclusion: The findings emphasized the key role the IFL plays in hip flexion by working synergistically with the hip musculature. Clinical Relevance: The importance of the contribution of the IFL to the hip flexors warrants careful handling and repair of these ligaments in cases of surgery and structural damage.

Contributions of the ischiofemoral ligament, iliofemoral ligament, and conjoined tendon to hip stability after total hip arthroplasty: A cadaveric study.

An adequate soft tissue balance is important in total hip arthroplasty (THA). This study assessed the contribution of the iliofemoral ligament, ischiofemoral ligament, and conjoined tendon to the range of hip rotation after THA and hip stability in response to axial traction. THA was performed in eight fresh-frozen cadaveric specimens via an anterolateral approach using a navigation system. The ischiofemoral ligament, the medial arm of the iliofemoral ligament, and the conjoined tendon were resected in that order. The ranges of external and internal rotation and the amount of movement of the femoral head in response to axial traction were measured with the hip in 10° of extension, the neutral position, and in 10°, 30°, and 60° of flexion. Resection of the medial arm of the iliofemoral ligament significantly increased the range of external rotation in 10° of extension, the neutral position, and in 10°, 30°, and 60° of flexion. The conjoined tendon was the most important inhibitor of internal rotation from 10° of extension to 30° of flexion. Although each single element had a minor role in stabilizing the hip when axial traction was applied, resection of two or more elements significantly affected joint stability. The iliofemoral ligament and conjoined tendon are the main inhibitors of external rotation and internal rotation, respectively, when THA is performed using an anterior or anterolateral approach. Resection of two or more elements could greatly affect hip stability when axial traction is applied.

Pericapsular Nerve Group Block and Iliopsoas Plane Block: A Scoping Review of Quadriceps Weakness after Two Proclaimed Motor-Sparing Hip Blocks.

Iliopsoas plane (IP) is a fascial plane deep to the iliopsoas complex that can serve as a potential space for the injection of local anesthetics to selectively block the articular branches of femoral nerve and accessory obturator nerve to the anterior hip capsule. Two highly similar ultrasound-guided interfascial plane blocks that target the IP, pericapsular nerve group (PENG) block and iliopsoas plane block (IPB), were both designed to achieve motor-sparing sensory block to the anterior hip capsule. However, the most recent evidence shows that PENG block can cause 25% or more of quadriceps weakness, while IPB remains the hip block that can preserve quadriceps strength. In this scoping review of quadriceps weakness after PENG block and IPB, we first performed a focused review on the complicated anatomy surrounding the anterior hip capsule. Then, we systematically searched for all currently available cadaveric and clinical studies utilizing PENG block and IPB, with a focus on quadriceps weakness and its potential mechanism from the perspectives of fascial plane spread along and outside of the IP. We conclude that quadriceps weakness after PENG block, which places its needle tip directly deep to iliopsoas tendon (IT), may be the result of iliopectineal bursal injection. The incidental bursal injection, which can be observed on ultrasound as a medial fascial plane spread, can cause bursal rupture/puncture and an anteromedial extra-IP spread to involve the femoral nerve proper within fascia iliaca compartment (FIC). In comparison, IPB places its needle tip lateral to IT and injects just one-fourth of the volume of PENG block. The current evidence, albeit still limited, supports IPB as the true motor-sparing hip block. To avoid quadriceps weakness after PENG block, a more laterally placed needle tip, away from the undersurface of IT, and a reduction in injection volume should be considered. Future studies should focus on comparing the analgesic effects and quadriceps function impairment between PENG block and IPB.

Collagen I in the Hip Capsule Plays a Role in Postoperative Clinical Function in Patients With Developmental Dysplasia of the Hip.

The aims of the present study is to evaluate the roles of collagen I and III in the hip capsule in the postoperative clinical function of patients with developmental dysplasia of the hip (DDH). Hip capsules from 155 hips of 120 patients were collected during surgery. The patients were divided into three groups according to age: I: 2-3.5 years; II: 3.5-5 years; and III: 5-6 years. Patient clinical function and radiographic outcomes were evaluated with the McKay scores and Severin classification. The expression of collagen I and III was detected through immunohistochemistry and quantitative reverse transcription polymerase chain reaction (RT-PCR) and analyzed according to age, sex, degree of dislocation and McKay classification. All patients received open reduction and pelvic osteotomy and/or femoral shortening osteotomy and achieved good results on the basis of postoperative X-ray imaging. The average follow-up time was 3.4 years (range 2-4.3 years). There were no changes in the expression of collagen III in the different groups. The expression of collagen I according to age and sex was not significantly different. Lower expression of collagen I was observed in DDH patients with a higher degree of dislocation according to the Tonnis grade. The highest expression of collagen I was detected in the group with poor clinical function according to the McKay classification. Collagen I is correlated with the degree of dislocation and is a risk factor for poor clinical function in DDH patients. Collagen I is correlated with the degree of hip dislocation and poor clinical function in DDH patients.