Rotational femoral osteotomies and cam resection improve hip function and internal rotation for patients with anterior hip impingement and decreased femoral version.

Femoroacetabular impingement (FAI) patients with reduced femoral version (FV) are poorly understood. The aim of this study is to assess (i) hip pain and range of motion, (ii) subjective satisfaction and (iii) subsequent surgeries of symptomatic patients who underwent rotational femoral osteotomies. A retrospective case series involving 18 patients (23 hips, 2014-2018) with anterior hip pain that underwent rotational femoral osteotomies for treatment of decreased FV was performed. The mean preoperative age was 25 ± 6 years (57% male), and all patients had decreased FV < 10° and minimum 1-year follow-up (mean follow-up 2 ± 1 years). Surgical indication was the positive anterior impingement test, limited internal rotation (IR) in 90° of flexion (mean 10 ± 8°) and IR in extension (mean 24 ± 11°), anterosuperior chondrolabral damage in Magnet resonance (MR) arthrography, CT-based measurement of decreased FV (mean 5 ± 3°, Murphy method) and no osteoarthritis (Tönnis Grade 0). Most patients had intra- and extra-articular subspine FAI (patient-specific 3D impingement simulation). Subtrochanteric rotational femoral osteotomies to increase FV (correction 20 ± 4°) were combined with cam resection (78%) and surgical hip dislocation (91%). (i) The positive anterior impingement test decreased significantly (P < 0.001) from pre- to postoperatively (100% to 9%). IR in 90° of flexion increased significantly (P < 0.001, 10 ± 8° to 31 ± 10°). (ii) Subjective satisfaction increased significantly (P < 0.001) from pre- to postoperatively (33% 77%). The mean Merle d'Aubigné and Postel score increased significantly (P < 0.001) from 14 ± 2 (8-15) points to 17 ± 1 (13-18, P < 0.001) points. Most patients (85%) reported at follow-up that they would undergo surgery again. (iii) At follow-up, all 23 hips were preserved (no conversion to total hip arthroplasty). One hip (4%) underwent revision osteosynthesis. Proximal rotational femoral osteotomies combined with cam resection improve hip pain and IR in most FAI patients with decreased FV at short-term follow-up. Rotational femoral osteotomies to increase FV are safe and effective.

Impulsivity mediates the association between narcissism and substance-related problems beyond the degree of substance use: a longitudinal observational study.

BACKGROUND: Narcissism has been implied as a putative risk factor for substance use disorders (SUDs). However, previous research did not disentangle the degree of substance use from substance-related problems, the symptoms of SUDs. This preregistered study addressed the open question whether grandiose and vulnerable narcissism and their constituent traits convey specific SUD risk, that is, explain substance-related problems beyond the degree of use. Furthermore, we tested whether impulsivity or substance use motives linked to narcissistic self-regulation mediate this association. METHODS: Narcissism, impulsivity, substance use motives, past-year substance use, and substance-related problems were assessed in 139 (poly-)substance users, 121 of whom completed a one-year follow-up. For significant longitudinal associations between narcissism factors and substance-related problems controlled for the degree of use, we tested impulsivity and substance use motives as mediators. RESULTS: Grandiose narcissism (r =.24, p =.007) and its constituent factors antagonistic (r =.27, p =.003) and agentic narcissism (r =.18, p =.050), but not vulnerable narcissism, prospectively predicted substance-related problems beyond the degree of substance use. Associations of grandiose narcissism and antagonistic narcissism with substance-related problems were fully mediated by impulsivity, but not substance use motives. Impulsivity explained roughly one third of the association of both grandiose (P̂M = 0.30) and antagonistic narcissism (P̂M = 0.26) with substance-related problems. DISCUSSION: We demonstrate that grandiose narcissism- particularly antagonistic but also agentic narcissism- is specifically linked to substance-related problems beyond the degree of substance use. The mediating effect of impulsivity but not substance use motives suggests that impulsivity may be a more important mechanism than narcissistic self-regulation in promoting SUD in narcissism. However, future studies may use more targeted measures than substance use motives to further probe the role of self-regulation. Similar result patterns for alcohol compared to all substances together indicate that mechanisms may be alike across substances. In conclusion, narcissistic individuals may not use substances more but have a higher SUD risk, informing prevention and treatment.

Social Comparison Processes of Hispanic Students at Hispanic Majority Institutions.

This paper describes the types of social comparison used by Hispanic students at a Hispanic Majority Institution through two studies (N = 406). We found that students engaged in upward identification more often than downward identification, downward contrast, and upward contrast. However, when comparing themselves on an academic measure, downward identification and upward contrast became relatively more frequent. Additionally, downward identification tended to predict higher self-reported confidence about academic abilities than other types of social comparison.

Are degenerative findings detected on traction MR arthrography of the hip associated with failure of arthroscopic femoroacetabular impingement surgery?

OBJECTIVES: To identify preoperative degenerative features on traction MR arthrography associated with failure after arthroscopic femoroacetabular impingement (FAI) surgery. METHODS: Retrospective study including 102 patients (107 hips) undergoing traction magnetic resonance arthrography (MRA) of the hip at 1.5 T and subsequent hip arthroscopic FAI surgery performed (01/2016 to 02/2020) with complete follow-up. Clinical outcomes were assessed using the International Hip Outcome Tool (iHOT-12) score. Clinical endpoint for failure was defined as an iHOT-12 of < 60 points or conversion to total hip arthroplasty. MR images were assessed by two radiologists for presence of 9 degenerative lesions including osseous, chondrolabral/ligamentum teres lesions. Uni- and multivariate Cox regression analysis was performed to assess the association between MRI findings and failure of FAI surgery. RESULTS: Of the 107 hips, 27 hips (25%) met at least one endpoint at a mean 3.7 ± 0.9 years follow-up. Osteophytic changes of femur or acetabulum (hazard ratio [HR] 2.5-5.0), acetabular cysts (HR 3.4) and extensive cartilage (HR 5.1) and labral damage (HR 5.5) > 2 h on the clockface were univariate risk factors (all p < 0.05) for failure. Three risk factors for failure were identified in multivariate analysis: Acetabular cartilage damage > 2 h on the clockface (HR 3.2, p = 0.01), central femoral osteophyte (HR 3.1, p = 0.02), and femoral cartilage damage with ligamentum teres damage (HR 3.0, p = 0.04). CONCLUSION: Joint damage detected by preoperative traction MRA is associated with failure 4 years following arthroscopic FAI surgery and yields promise in preoperative risk stratification. CLINICAL RELEVANCE STATEMENT: Evaluation of negative predictors on preoperative traction MR arthrography holds the potential to improve risk stratification based on the already present joint degeneration ahead of FAI surgery. KEY POINTS: • Osteophytes, acetabular cysts, and extensive chondrolabral damage are risk factors for failure of FAI surgery. • Extensive acetabular cartilage damage, central femoral osteophytes, and combined femoral cartilage and ligamentum teres damage represent independent negative predictors. • Survival rates following hip arthroscopy progressively decrease with increasing prevalence of these three degenerative findings.

Dissociating the Link of Neural Correlates of Inhibition to the Degree of Substance Use and Substance-Related Problems: A Preregistered, Multimodal, Combined Cross-sectional and Longitudinal Study.

BACKGROUND: Frontal hypoactivation during inhibition is a promising phenotype for substance use disorders (SUDs), but studies comparing individuals with SUDs with unaffected individuals have reported inconsistent results. This may result from distinctive associations of neural correlates of inhibition with the degree of substance use and the severity of substance-related problems-two correlated but distinct facets of SUDs-reflecting a potentially disregarded confounding effect. This preregistered study tested whether frontal hypoactivation during inhibition is specifically linked to substance-related problems in SUDs beyond the degree of substance use. METHODS: A stop signal task during functional magnetic resonance imaging, trait self-control, substance use, and substance-related problems in the past 12 months were assessed in 121 (poly)substance users. One hundred seven participants completed a 1-year follow-up. We examined the association between multimodal indicators of inhibition (neural activation in regions of interest, inhibitory performance, trait self-control) and substance-related problems while controlling for the degree of substance use. RESULTS: Right inferior frontal gyrus hypoactivation explained variance in substance-related problems beyond the degree of substance use, while hyperactivation in the same region explained variance in the degree of substance use beyond the effects of substance-related problems, both cross-sectionally (problems: Bonferroni-Holm-corrected p = .048; use: p < .01) and prospectively (problems at trend level: p = .096; use: p = .01). Trait and behavioral inhibition were unrelated to problems beyond the effects of substance use (ps > .05). CONCLUSIONS: We demonstrated that frontal hypoactivation during inhibition specifically relates to substance-related problems. Interestingly, increased activity may even represent a resilience factor in substance use without SUDs. Future studies should distinguish between processes linked to the degree of substance use and substance-related problems to advance understanding of why some substance users develop SUDs and others do not.

Playful mouth-to-mouth interactions of belugas (Delphinapterus leucas) in managed care.

Belugas (Delphinapterus leucas) engage in many forms of play (e.g., object, water, locomotor), but no play is quite as curious as the unusual form of cooperative social play involving mouth-to-mouth interactions. These playful interactions are characterized by two belugas approaching each other head-to-head and interlocking their jaws, clasping one another, as if they were shaking hands. Observed in belugas both in the wild and in managed care, it is seemingly an important type of social play that offers a unique way of socializing with conspecifics. To describe this unusual behavior, a group of belugas in managed care was observed from 2007 to 2019. Although adults participated in mouth-to-mouth interactions, most were initiated and received by young belugas. Both males and females engaged in mouth-to-mouth interactions and did so at similar frequencies. Individual differences in how many mouth-to-mouth interactions were initiated among calves were also observed. Due to the unique, cooperative nature of mouth-to-mouth interactions, which require both social and motor skills, it is hypothesized that these interactions may be used to test social and motor competency.

Can gadolinium contrast agents be replaced with saline for direct MR arthrography of the hip? A pilot study with arthroscopic comparison.

OBJECTIVE: To compare image quality and diagnostic performance of preoperative direct hip magnetic resonance arthrography (MRA) performed with gadolinium contrast agent and saline solution. METHODS: IRB-approved retrospective study of 140 age and sex-matched symptomatic patients with femoroacetabular impingement, who either underwent intra-articular injection of 15-20 mL gadopentetate dimeglumine (GBCA), 2.0 mmol/L ("GBCA-MRA" group, n = 70), or 0.9% saline solution ("Saline-MRA" group, n = 70) for preoperative hip MRA and subsequent hip arthroscopy. 1.5 T hip MRA was performed including leg traction. Two readers assessed image quality using a 5-point Likert scale (1-5, excellent-poor), labrum and femoroacetabular cartilage lesions. Arthroscopic diagnosis was used to calculate diagnostic accuracy which was compared between groups with Fisher's exact tests. Image quality was compared with the Mann-Whitney U tests. RESULTS: Mean age was 33 years ± 9, 21% female patients. Image quality was excellent (GBCA-MRA mean range, 1.1-1.3 vs 1.1-1.2 points for Saline-MRA) and not different between groups (all p > 0.05) except for image contrast which was lower for Saline-MRA group (GBCA-MRA 1.1 ± 0.4 vs Saline-MRA 1.8 ± 0.5; p < 0.001). Accuracy was high for both groups for reader 1/reader 2 for labrum (GBCA-MRA 94%/ 96% versus Saline-MRA 96%/93%; p > 0.999/p = 0.904) and acetabular (GBCA-MRA 86%/ 83% versus Saline-MRA 89%/87%; p = 0.902/p = 0.901) and femoral cartilage lesions (GBCA-MRA 97%/ 99% versus Saline-MRA 97%/97%; both p > 0.999). CONCLUSION: Diagnostic accuracy and image quality of Saline-MRA and GBCA-MRA is high in assessing chondrolabral lesions underlining the potential role of non-gadolinium-based hip MRA. KEY POINTS: • Image quality of Saline-MRA and GBCA-MRA was excellent for labrum, acetabular and femoral cartilage, ligamentum teres, and the capsule (all p > 0.18). • The overall image contrast was lower for Saline-MRA (Saline-MRA 1.8 ± 0.5 vs. GBCA-MRA 1.1 ± 0.4; p < 0.001). • Diagnostic accuracy was high for Saline-MRA and GBCA-MRA for labrum (96% vs. 94%; p > 0.999), acetabular cartilage damage (89% vs. 86%; p = 0.902), femoral cartilage damage (97% vs. 97%; p > 0.999), and extensive cartilage damage (97% vs. 93%; p = 0.904).

A Deep Learning Method for Quantification of Femoral Head Necrosis Based on Routine Hip MRI for Improved Surgical Decision Making.

(1) Background: To evaluate the performance of a deep learning model to automatically segment femoral head necrosis (FHN) based on a standard 2D MRI sequence compared to manual segmentations for 3D quantification of FHN. (2) Methods: Twenty-six patients (thirty hips) with avascular necrosis underwent preoperative MR arthrography including a coronal 2D PD-w sequence and a 3D T1 VIBE sequence. Manual ground truth segmentations of the necrotic and unaffected bone were then performed by an expert reader to train a self-configuring nnU-Net model. Testing of the network performance was performed using a 5-fold cross-validation and Dice coefficients were calculated. In addition, performance across the three segmentations were compared using six parameters: volume of necrosis, volume of unaffected bone, percent of necrotic bone volume, surface of necrotic bone, unaffected femoral head surface, and percent of necrotic femoral head surface area. (3) Results: Comparison between the manual 3D and manual 2D segmentations as well as 2D with the automatic model yielded significant, strong correlations (Rp > 0.9) across all six parameters of necrosis. Dice coefficients between manual- and automated 2D segmentations of necrotic- and unaffected bone were 75 ± 15% and 91 ± 5%, respectively. None of the six parameters of FHN differed between the manual and automated 2D segmentations and showed strong correlations (Rp > 0.9). Necrotic volume and surface area showed significant differences (all p < 0.05) between early and advanced ARCO grading as opposed to the modified Kerboul angle, which was comparable between both groups (p > 0.05). (4) Conclusions: Our deep learning model to automatically segment femoral necrosis based on a routine hip MRI was highly accurate. Coupled with improved quantification for volume and surface area, as opposed to 2D angles, staging and course of treatment can become better tailored to patients with varying degrees of AVN.

Keep Calm and Be Humble: Can Intellectual Humility Predict Test Anxiety?

Test anxiety is common and may lead to a range of negative outcomes, including poor exam performance. Therefore, it is important to explore psychological predictors of test anxiety. In this paper, we examined whether intellectual humility can predict test anxiety. In Study 1, college students (N = 181) completed an intellectual humility measure with four subscales and two different measures of test anxiety. In Study 2 (N = 196), a community sample recruited from an online workforce completed the same measures. In both studies, we found that intellectual humility was negatively related to test anxiety, such that higher intellectual humility predicted lower test anxiety. Specifically, Study 1 demonstrated a negative correlation between intellectual humility and the Sarason Test Anxiety Scale; Study 2 confirmed this negative relationship with both the Sarason and Westside test anxiety scales. We also found that this relationship was largely driven by the intellectual humility subscale of Independence of Intellect and Ego. Additionally, these results were present even when controlling for key demographic factors. These findings highlight intellectual humility's role in predicting exam anxiety and offer a potential avenue for intellectual humility to be leveraged into interventions to decrease exam anxiety in the future.

Context Matters: Stress for Minority Students Who Attend Minority-Majority Universities.

Research on college student stress has typically focused on institutions where the student population is predominately White and continuing-generation. This study explored student stress in a unique context-a public regional university where the majority of students are Latinx, first-generation (FGCS), and of low socioeconomic status (SES). Of the 355 participants in the study, 72.4% self-identified as Latinx and 59.7% were FGCS. Additionally, on a subjective scale of socioeconomic status (1 = lowest, 10 = highest), the mean response was 5.76 (SD = 1.56). Participants (18 years old or older) who were enrolled in a first-year seminar course were recruited for this study. Through an online survey during Fall 2018, first-year students reported levels of perceived and experienced stress related to academic, economic, intrapersonal, and interpersonal concerns. Results of regression analyses indicated that most types of stress were predicted by students' Latinx identity status and SES; FGCS status did not significantly predict stress. These findings highlight the need to explore solutions to address stress for Latinx and/or low SES students. Additionally, the study underscores the necessity of conducting research at educational institutions in which Latinx, FGC, and low SES students comprise the majority of the student body.

Combined femoral and acetabular version is sex-related and differs between patients with hip dysplasia and acetabular retroversion.

AIMS: Frequency of abnormal femoral and acetabular version (AV) and combinations are unclear in patients with developmental dysplasia of the hip (DDH). This study aimed to investigate femoral version (FV), the proportion of increased FV and femoral retroversion, and combined-version (CV, FV+AV) in DDH patients and acetabular-retroversion (AR). PATIENTS AND METHODS: A retrospective IRB-approved observational study was performed with 78 symptomatic DDH patients (90 hips) and 65 patients with femoroacetabular-impingement (FAI) due to AR (77 hips, diagnosis on AP radiographs). CT/MRI-based measurement of FV (Murphy method) and central AV were compared. Frequency of increased FV(FV > 25°), severely increased FV (FV > 35°) and excessive FV (FV > 45°) and of decreased FV (FV < 10°) and CV (McKibbin-index/COTAV-index) was analysed. RESULTS: Mean FV and CV was significantly (p < 0.001) increased of DDH patients (mean ± SD of 25 ± 11° and 47 ± 18°) compared to AR (16 ± 11° and 28 ± 13°). Mean FV of female DDH patients (27 ± 16°) and AR (19 ± 12°) was significantly (p < 0.001) increased compared to male DDH patients (18 ± 13°) and AR (13 ± 8°). Frequency of increased FV (>25°) was 47% and of severely increased FV (>35°) was 23% for DDH patients. Proportion of femoral retroversion (FV < 10°) was significantly (p < 0.001) higher in patients AR (31%) compared to DDH patients (17%). 18% of DDH patients had AV > 25° combined with FV > 25°. Of patients with AR, 12% had FV < 10° combined with AV < 10°. CONCLUSION: Patients with DDH and AR have remarkable sex-related differences of FV and CV. Frequency of severely increased FV > 35° (23%) is considerable for patients with DDH, but 17% exhibited decreased FV, that could influence management. The different combinations underline the importance of patient-specific evaluation before open hip preservation surgery (periacetabular osteotomy and femoral derotation osteotomy) and hip-arthroscopy.

Coxa valga and antetorta increases differences among different femoral version measurements : potential implications for derotational femoral osteotomy planning.

AIMS: To evaluate how abnormal proximal femoral anatomy affects different femoral version measurements in young patients with hip pain. METHODS: First, femoral version was measured in 50 hips of symptomatic consecutively selected patients with hip pain (mean age 20 years (SD 6), 60% (n = 25) females) on preoperative CT scans using different measurement methods: Lee et al, Reikerås et al, Tomczak et al, and Murphy et al. Neck-shaft angle (NSA) and α angle were measured on coronal and radial CT images. Second, CT scans from three patients with femoral retroversion, normal femoral version, and anteversion were used to create 3D femur models, which were manipulated to generate models with different NSAs and different cam lesions, resulting in eight models per patient. Femoral version measurements were repeated on manipulated femora. RESULTS: Comparing the different measurement methods for femoral version resulted in a maximum mean difference of 18° (95% CI 16 to 20) between the most proximal (Lee et al) and most distal (Murphy et al) methods. Higher differences in proximal and distal femoral version measurement techniques were seen in femora with greater femoral version (r > 0.46; p < 0.001) and greater NSA (r > 0.37; p = 0.008) between all measurement methods. In the parametric 3D manipulation analysis, differences in femoral version increased 11° and 9° in patients with high and normal femoral version, respectively, with increasing NSA (110° to 150°). CONCLUSION: Measurement of femoral version angles differ depending on the method used to almost 20°, which is in the range of the aimed surgical correction in derotational femoral osteotomy and thus can be considered clinically relevant. Differences between proximal and distal measurement methods further increase by increasing femoral version and NSA. Measurement methods that take the entire proximal femur into account by using distal landmarks may produce more sensitive measurements of these differences.Cite this article: Bone Jt Open 2022;3(10):759-766.

[Treatment strategies for the combination of hip dysplasia, femoroacetabular impingement and malrotation of the proximal femur : How much should be corrected?] / Therapieentscheidung bei Kombinationspathologien Dysplasie ­ FAI ­ Fehlrotation : Wann und wieviel sollte korrigiert werden?

BACKGROUND: Hip dysplasia, FAI and femoral malrotation often occur together, resulting in mixed symptoms and severe biomechanical limitations of the hip. OBJECTIVES: To report on the current recommendations for the best possible diagnosis and treatment strategies of combination pathologies in hip-preserving surgery. METHODS: Review and discussion of the relevant literature with consideration of own experience in the treatment of complex combined pathomorphologies of the hip. RESULTS: Patient history and a thorough clinical examination are key for determining the predominant pathomorphologies causing the symptoms. Standardized conventional ap pelvic and axial images of the hip are the basis for the radiological assessment of the hip, supplemented with MRI, CT and animations of the hip, depending on the case. As the pathologies influence each other functionally, a stepwise approach to treatment is recommended. The functionally most relevant pathology is treated first, followed by further corrections as needed. The primary goal is to achieve a stable hip with normal acetabular coverage, followed by an impingement-free range of motion and normalized musculoskeletal function. Care must be taken in the choice of surgical method to ensure that all pathologies can be adequately treated. CONCLUSION: Complex, combined pathologies of the hip can be treated sufficiently with hip-preserving surgery. A thorough diagnosis is important in order to recognize the functional interaction of the different pathologies. The goal of the surgical therapy is a correctly covered, stable hip with a normal range of motion.

Automated quantification of cartilage quality for hip treatment decision support.

PURPOSE: Preservation surgery can halt the progress of joint degradation, preserving the life of the hip; however, outcome depends on the existing cartilage quality. Biochemical analysis of the hip cartilage utilizing MRI sequences such as delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), in addition to morphological analysis, can be used to detect early signs of cartilage degradation. However, a complete, accurate 3D analysis of the cartilage regions and layers is currently not possible due to a lack of diagnostic tools. METHODS: A system for the efficient automatic parametrization of the 3D hip cartilage was developed. 2D U-nets were trained on manually annotated dual-flip angle (DFA) dGEMRIC for femoral head localization and cartilage segmentation. A fully automated cartilage sectioning pipeline for analysis of central and peripheral regions, femoral-acetabular layers, and a variable number of section slices, was developed along with functionality for the automatic calculation of dGEMRIC index, thickness, surface area, and volume. RESULTS: The trained networks locate the femoral head and segment the cartilage with a Dice similarity coefficient of 88 ± 3 and 83 ± 4% on DFA and magnetization-prepared 2 rapid gradient-echo (MP2RAGE) dGEMRIC, respectively. A completely automatic cartilage analysis was performed in 18s, and no significant difference for average dGEMRIC index, volume, surface area, and thickness calculated on manual and automatic segmentation was observed. CONCLUSION: An application for the 3D analysis of hip cartilage was developed for the automated detection of subtle morphological and biochemical signs of cartilage degradation in prognostic studies and clinical diagnosis. The segmentation network achieved a 4-time increase in processing speed without loss of segmentation accuracy on both normal and deformed anatomy, enabling accurate parametrization. Retraining of the networks with the promising MP2RAGE protocol would enable analysis without the need for B1 inhomogeneity correction in the future.

Investigation of lateralization of socio-sexual behavior in belugas (Delphinapterus leucas).

The majority of cetacean research suggests a right side/left cerebral hemisphere bias for processing visuospatial information and a left side/right cerebral hemisphere bias for processing social information. Beluga (Delphinapterus leucas) socio-sexual behavior involves motor skills coordination and is also hypothesized to serve a social function. The present study assessed whether 14 belugas in managed care displayed side bias in their lateral socio-sexual presentation behavior. No species-level bias was found, the majority of individuals did not display a side bias, and side use was not dependent on sex of the recipient, although some influence of swim direction was found. Only males had a statistically significant but small left side preference. Furthermore, there was a linear correlation with the left side being used increasingly more over Years 1-6 of life. This study suggests that belugas do not display consistent laterality of socio-sexual presentation behavior, which is in contrast to the laterality of mother-calf positions for belugas and the high levels of laterality that are reported for some behaviors of other cetacean species. Thus, it seems that beluga socio-sexual presentation behavior is flexible and may serve both motor skills practice and social functions, which likely involve both cerebral hemispheres as a cognitively engaging behavior.

Hip Impingement Location in Maximal Hip Flexion in Patients With Femoroacetabular Impingement With and Without Femoral Retroversion.

BACKGROUND: Symptomatic patients with femoroacetabular impingement (FAI) have limitations in daily activities and sports and report the exacerbation of hip pain in deep flexion. Yet, the exact impingement location in deep flexion and the effect of femoral version (FV) are unclear. PURPOSE: To investigate the acetabular and femoral locations of intra- or extra-articular hip impingement in flexion in patients with FAI with and without femoral retroversion. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: An institutional review board-approved retrospective study involving 84 hips (68 participants) was performed. Of these, symptomatic patients (37 hips) with anterior FAI and femoral retroversion (FV <5°) were compared with symptomatic patients (21 hips) with anterior FAI (normal FV) and with a control group (26 asymptomatic hips without FAI and normal FV). All patients were symptomatic, had anterior hip pain, and had positive anterior impingement test findings. Most of the patients had hip/groin pain in maximal flexion or deep flexion or during sports. All 84 hips underwent pelvic computed tomography (CT) to measure FV as well as validated dynamic impingement simulation with patient-specific CT-based 3-dimensional models using the equidistant method. RESULTS: In maximal hip flexion, femoral impingement was located anterior-inferior at 4 o'clock (57%) and 5 o'clock (32%) in patients with femoral retroversion and mostly at 5 o'clock in patients without femoral retroversion (69%) and in asymptomatic controls (76%). Acetabular intra-articular impingement was located anterior-superior (2 o'clock) in all 3 groups. In 125° of flexion, patients with femoral retroversion had a significantly (P < .001) higher prevalence of anterior extra-articular subspine impingement (54%) and anterior intra-articular impingement (89%) compared with the control group (29% and 62%, respectively). CONCLUSION: Knowing the exact location of hip impingement in deep flexion has implications for surgical treatment, sports, and physical therapy and confirms previous recommendations: Deep flexion (eg, during squats/lunges) should be avoided in patients with FAI and even more in patients with femoral retroversion. Patients with femoral retroversion may benefit and have less pain when avoiding deep flexion. For these patients, the femoral location of the impingement conflict in flexion was different (anterior-inferior) and distal to the cam deformity compared with the location during the anterior impingement test (anterior-superior). This could be important for preoperative planning and bone resection (cam resection or acetabular rim trimming) during hip arthroscopy or open hip preservation surgery to ensure that the region of impingement is appropriately identified before treatment.

Combined abnormalities of femoral version and acetabular version and McKibbin Index in FAI patients evaluated for hip preservation surgery.

Frequencies of combined abnormalities of femoral version (FV) and acetabular version (AV) and of abnormalities of the McKibbin index are unknown. To investigate the prevalence of combined abnormalities of FV and AV and of abnormalities of the McKibbin index in symptomatic patients with femoroacetabular impingement (FAI), a retrospective, Institutional Review Board (IRB)-approved study of 333 symptomatic patients (384 hips) that were presented with hip pain and FAI was performed. The computed tomography/magnetic resonance imaging based measurement of central AV, cranial AV and FV was compared among five subgroups with distinguished FAI subgroups and patients that underwent a hip preservation surgery. The allocation to each subgroup was based on AP radiographs. Normal AV and FV were 10-25°. The McKibbin index is the sum of central AV and FV. Of patients that underwent a hip preservation surgery, 73% had a normal McKibbin index (20-50°) but 27% had an abnormal McKibbin index. Of all patients, 72% had a normal McKibbin index, but 28% had abnormal McKibbin index. The prevalence of combined abnormalities of FV and AV varied among subgroups: a higher prevalence of decreased central AV combined with decreased FV of patients with acetabular-retroversion group (12%) and overcoverage (11%) was found compared with mixed-type FAI (5%). Normal AV combined with normal FV was present in 41% of patients with cam-type FAI and in 34% of patients with overcoverage. Patients that underwent a hip preservation surgery had normal mean FV (17 ± 11°), central AV (19 ± 7°), cranial AV (16 ± 10°) and McKibbin index (36 ± 14°). Frequency of combined abnormalities of AV and FV differs between subgroups of FAI patients. Aggravated and compensated McKibbin index was prevalent in FAI patients. This has implications for open hip preservation surgery (surgical hip dislocation or femoral derotation osteotomy) or hip arthroscopy or non-operative treatment.

The emergence and early development of socio-sexual behavior in beluga calves (Delphinapterus leucas).

While the ontogeny of beluga (Delphinapterus leucas) socio-sexual behavior has been documented in animals between 37- and 108-months-old, the first 36 months of life are yet to be examined. This study investigated how socio-sexual behaviors emerge over the first three years of life in a group of belugas in managed care. The emergence of socio-sexual behaviors was relatively consistent among immature animals. More complex behaviors, like s-posture presentations, developed in a piecemeal fashion (i.e., simple components of the behavior sequence emerged before complex components). The presence of an adult male significantly predicted if immature belugas would initiate and participate in socio-sexual behavior. However, partner preferences changed with age. In the first year of life, belugas engaged in sexual behavior with their mother most frequently but preferred to play with older males if given a choice. By the third year of life, belugas engaged in socio-sexual behavior most frequently with other immature animals. These findings enhance our understanding of how belugas develop sexually and socially and have implications for social housing practices of immature belugas.

How frequent is absolute femoral retroversion in symptomatic patients with cam- and pincer-type femoroacetabular impingement?

AIMS: The frequency of severe femoral retroversion is unclear in patients with femoroacetabular impingement (FAI). This study aimed to investigate mean femoral version (FV), the frequency of absolute femoral retroversion, and the combination of decreased FV and acetabular retroversion (AR) in symptomatic patients with FAI subtypes. METHODS: A retrospective institutional review board-approved observational study was performed with 333 symptomatic patients (384 hips) with hip pain due to FAI evaluated for hip preservation surgery. Overall, 142 patients (165 hips) had cam-type FAI, while 118 patients (137 hips) had mixed-type FAI. The allocation to each subgroup was based on reference values calculated on anteroposterior radiographs. CT/MRI-based measurement of FV (Murphy method) and AV were retrospectively compared among five FAI subgroups. Frequency of decreased FV < 10°, severely decreased FV < 5°, and absolute femoral retroversion (FV < 0°) was analyzed. RESULTS: A significantly (p < 0.001) lower mean FV was found in patients with cam-type FAI (15° (SD 10°)), and in patients with mixed-type FAI (17° (SD 11°)) compared to severe over-coverage (20° (SD 12°). Frequency of decreased FV < 10° was significantly (p < 0.001) higher in patients with cam-type FAI (28%, 46 hips) and in patients with over-coverage (29%, 11 hips) compared to severe over-coverage (12%, 5 hips). Absolute femoral retroversion (FV < 0°) was found in 13% (5 hips) of patients with over-coverage, 6% (10 hips) of patients with cam-type FAI, and 5% (7 hips) of patients with mixed-type FAI. The frequency of decreased FV< 10° combined with acetabular retroversion (AV < 10°) was 6% (8 hips) in patients with mixed-type FAI and 5% (20 hips) in all FAI patients. Of patients with over-coverage, 11% (4 hips) had decreased FV < 10° combined with acetabular retroversion (AV < 10°). CONCLUSION: Patients with cam-type FAI had a considerable proportion (28%) of decreased FV < 10° and 6% had absolute femoral retroversion (FV < 0°), even more for patients with pincer-type FAI due to over-coverage (29% and 13%). This could be important for patients evaluated for open hip preservation surgery or hip arthroscopy, and each patient requires careful personalized evaluation. Cite this article: Bone Jt Open 2022;3(7):557-565.