Accuracy of navigated cam resection in femoroacetabular impingement: A randomised controlled trial.

BACKGROUND: The main cause for revision hip arthroscopy surgery is incomplete bony resection of femoroacetabular impingement (FAI). This study aimed to compare the cam resection accuracy via the conventional hip arthroscopy technique with the navigation technique. METHODS: Two prospectively randomized groups were recruited: navigated (n = 15) and conventional (n = 14). A pre-operative CT and post-operative MRI scan were obtained in all cases to compare alpha angle, range of motion simulation and determine a pre-operative 3D surgical resection plan. RESULTS: Post-operatively, the mean maximal alpha angle improved significantly in the navigated group compared with the conventional group (55°vs.66°; P = 0.023), especially in the 12 o' clock position (45°vs.60°; P = 0.041). However, positioning time and radiation exposure were significantly longer in the navigated group. CONCLUSION: Navigated surgery is effective for patients with cam type FAI in helping restore normal anatomy, however, not without drawbacks. Larger studies will be required to validate our results.Jan Van Houcke was supported by a doctoral grant of the Research Foundation‐Flanders

Pre-operative Planning and Intra-operative Guidance for Shoulder Replacement Surgery

Shoulder joint replacement, or arthroplasty, is indicated in cases where arthritis or trauma has resulted in severe joint damage that in turn causes increased pain and decreased function. However, shoulder arthroplasty is less successful than hip and knee replacement, mostly due to the complexity of the shoulder joint and the resultant complexity of the replacement operation. In this paper we present a complete visualization-oriented pre-operative planning and intra-operative guidance approach for shoulder joint replacement. Our system assists the surgeon by allowing a virtual arthroplasty procedure whilst giving feedback, primarily via patient- and procedure-specific joint range of motion (ROM) simulation and visualization. After a successful planning, our system automatically generates a 3D model of a patient-specific mechanical guidance device that is then produced by a rapid prototyping machine and can be used during the operation. In this way, a computer-based guidance system is not required in the operating room

Dynamic contact area ratio in shoulder instability: an innovative diagnostic technique measuring interplay of bony lesions

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Urban green is more than the absence of city: Structural and functional neural basis of urbanicity and green space in the neighbourhood of older adults

The relationship between urbanization, the brain, and human mental health is subject to intensive debate in the current scientific literature. Particularly, since mood and anxiety disorders as well as schizophrenia are known to be more frequent in urban compared to rural regions. Here, we investigated the association between cerebral signatures, mental health and land use indicators (Urban Fabric and Urban Green) within a 1 km radius around the home address of 207 well-characterized older adults. We observed a negative association between Urban Fabric coverage and a positive association between Urban Green coverage and grey matter volume in perigenual/subgenual anterior cingulate cortex (p/sACC). Although p/sACC has repeatedly been associated with depressive symptoms, neither brain structure nor land use categories were related to measures of mental health. However, resting-state measure in p/sACC showed a negative association with Urban Fabric in our healthy sample, reminiscent of previous reports on major depression where p/sACC is often found to be reduced in activation. Interestingly, hierarchical regression analyses showed that Urban Green accounted for additional variance in brain structure beyond Urban Fabric. We take this finding as an exploratory result that hints at potentially salutogenic elements of green spaces (e.g. terpenes, nature sounds) that go beyond the absence of the detrimental elements of urban contexts (e.g. traffic noise, air pollution), which may inform the future search of environmental factors affecting mental health and disease

Location, location, location: the role of objective neighborhood characteristics for perceptions of control

Introduction: Control beliefs can protect against age-related declines in functioning. It is unclear whether neighborhood characteristics shape how much control people perceive over their life. This article studies associations of neighborhood characteristics with control beliefs of residents of a diverse metropolitan area (Berlin, Germany). Methods: We combine self-report data about perceptions of control obtained from participants in the Berlin Aging Study II (N = 507, 60-87 years, 51% women) with multisource geo-referenced indicators of neighborhood characteristics using linear regression models. Results: Findings indicate that objective neighborhood characteristics (i.e., unemployment rate) are indeed tied to perceptions of control, in particular, how much control participants feel others have over their lives. Including neighborhood characteristics in part doubled the amount of explained variance compared with a reference model covarying for demographic characteristics only (from R2 = 0.017 to R2 = 0.030 for internal control beliefs; R2 = 0.056 to R2 = 0.102 for external control beliefs in chance; R2 = 0.006 to R2 = 0.030 for external control beliefs in powerful others). Discussion/Conclusion: Findings highlight the importance of access to neighborhood resources for control beliefs across old age and can inform interventions to build up neighborhood characteristics which might be especially helpful in residential areas with high unemployment

Can combining femoral and acetabular morphology parameters improve the characterization of femoroacetabular impingement?

Femoroacetabular impingement (FAI) presupposes a dynamic interaction of the proximal femur and acetabulum producing clinical symptoms and chondrolabral damage. Currently, FAI classification is based on alpha angle and center-edge angle measurements in a single plane. However, acetabular and femoral version and neck-shaft angle also influence FAI. Furthermore, each of these parameters has a reciprocal interaction with the others; for example, a shallow acetabulum delays impingement of the femoral head with the acetabular rim. We introduce the new parameter "omega zone," which combines five parameters into one: the alpha and center-edge angles, acetabular and femoral version, and neck-shaft angle. We sought to determine whether the omega zone could differentiate patients with FAI from (1) normal control subjects (alpha < 55A degrees), but also from (2) control subjects with elevated alpha angles (a parts per thousand yenA 55A degrees). We evaluated CT data of 20 hips of male patients with symptomatic cam-type FAI and of 35 male hips extracted from 110 anonymized CT scans for vascular diagnosis. We excluded hips with osteoarthritis, developmental dysplasia, or coxa profunda (center-edge angle 20A degrees-45A degrees on AP pelvic view or corresponding coronal CT views). With dedicated software, femoral and pelvic orientation was standardized; we tested the omega zone in four hip positions in three distinct groups: patients with cam-type FAI (alpha > 60A degrees) and control subjects with normal (< 55A degrees) and high alpha angles (a parts per thousand yenA 55A degrees). The omega zone was smaller in patients with cam-type FAI than normal control subjects (alpha angle < 55A degrees) at 60A degrees and 90A degrees of flexion (mean, 12%; 95% confidence interval [CI], 7-17; p = 0.008; Cohen's d = 9%; 95% CI, 4-13; p = 0.003). Furthermore, the omega zone was smaller in all positions in patients with cam-type FAI than control subjects with high alpha angles (0A degrees p = 0.017, 30A degrees p = 0.004, 60A degrees p = 0.004, 90A degrees p = 0.007). In contrast, the omega zone did not differ between control subjects with normal or high alpha angles. In all hips, the omega zone decreased with flexion, corresponding to a decrease in remaining impingement-free motion with flexion. The omega zone visualizes and quantifies the interaction of the proximal femur and acetabulum. The omega zone differed between patients with cam-type FAI and control subjects with high alpha angles (a parts per thousand yen 55A degrees), who could not be distinguished based on alpha angle alone. For hip-preserving surgery, it can help surgeons decide whether to address the femur, the acetabulum, or both