Is Subcapital Realignment for Slipped Capital Femoral Epiphysis a Reproducible Technique? Midterm Results.

BACKGROUND: The modified Dunn procedure, which is based on the development of an extended retinacular flap containing the blood supply for the femoral head, allows anatomic reestablishment in patients with moderate to severe slipped capital femoral epiphysis (SCFE). Some controversy exists regarding the short-term to midterm risk of avascular necrosis (AVN) and other complications resulting from the surgical technique. QUESTIONS/PURPOSES: (1) What percentage of patients treated with an extended retinacular flap during the modified Dunn procedure for SCFE with a moderate (slip angle from 30° to 60°) or severe slip (slip angle equal or greater than 60°) develop symptomatic AVN, and what percentage underwent further surgery or had other complications? (2) What femoral head-neck alignment and position parameters relative to the greater trochanter are achieved after surgery? (3) Can we identify radiographic signs of osteoarthritis at a minimum of 4 years after surgery? METHODS: Between January 2006 and December 2018, we treated 61 patients for SCFE. During this time, we generally used the modified Dunn procedure when the slip angle was ≥ 30°. Based on this indication, the modified Dunn procedure was performed in 37 patients (41 hips) during that time period, and those patients were potentially eligible for this retrospective study. Because bilateral hips in the same patient are not statistically independent, for our analyses, we analyzed only the hip with the longer follow-up time. Of those who remained, 11% (4) were lost before the minimum study follow-up of 48 months or had incomplete datasets, leaving 89% (33) for analysis here at a median follow-up of 80 months (range 49 to 208 months). Periacetabular osteotomy or subtrochanteric rotational femoral osteotomy was added under the same anaesthesia time in 33% (11 patients). We added periacetabular osteotomy in 24% (8) when intraoperative anterior instability was present in external rotation. A femoral rotational osteotomy was added in 9% (3) when posterior instability was present in flexion and internal rotation. The mean ± standard deviation age at the time of surgery was 13 ± 1 years, and 33% (11 of 33) of patients were female. The mean slip angle was 51° ± 16º, and 15% (5) of hips had unstable slips, defined as an inability to walk with or without crutches. We documented chronic presentations in 82% (27) of patients, acute and chronic in 12% (4), and acute in 6% (2). The rate of symptomatic AVN was determined by reviewing all radiographs obtained at the latest follow-up interval. Further surgery and other complications were assessed through an electronic medical record review. Radiographic morphologic parameters were measured before surgery and at a minimum follow-up of 4 years by two senior orthopaedic surgeons. Radiographs obtained at the latest follow-up visit were also screened for signs of osteoarthritis by the same surgeons. RESULTS: At the latest follow-up, 3% (1 patient) of patients developed symptomatic AVN and underwent further surgery and 3% (1) underwent revision surgery for screw breakage after a high-energy fall. Postoperatively, the alpha angle was restored to 39º ± 6º, the anterior head-neck offset was restored to 8 ± 3 mm, the neck-shaft angle was 136º ± 6º, and the presence of a positive Klein line decreased from 64% (21 hips) to 0% (0 hips). No patients showed radiographic signs of osteoarthritis at the minimum follow-up of 4 years. CONCLUSION: In this series, the modified Dunn procedure in moderate and severe slips was a reproducible procedure, and few patients developed symptomatic AVN or experienced other complications. Hip morphology was restored, but a longer follow-up duration and a detailed analysis of the results from other centers is warranted to assess the possible long-term risk of progression to AVN or osteoarthritis. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Evaluating Link Lifetime Prediction to Support Computational Offloading Decision in VANETs.

In urban mobility, Vehicular Ad Hoc Networks (VANETs) provide a variety of intelligent applications. By enhancing automobile traffic management, these technologies enable advancements in safety and help decrease the frequency of accidents. The transportation system can now follow the development and growth of cities without sacrificing the quality and organisation of its services thanks to safety apps that include collision alerts, real-time traffic information, and safe driving applications, among others. Applications can occasionally demand a lot of computing power, making their processing impractical for cars with limited onboard processing capacity. Offloading of computation is encouraged by such a restriction. However, because vehicle mobility operations are dynamic, communication times (also known as link lifetimes) between nodes are frequently short. VANET applications and processes are impacted by such communication delays (e.g., the offloading decision when using the Computational Offloading technique). Making an accurate prediction of the link lifespan between vehicles is therefore challenging. The effectiveness of the communication time estimation is currently constrained by the link lifespan prediction methods used in the computational offloading process. This work investigates five machine learning (ML) algorithms to predict the link lifetime between nodes in VANETs in different scenarios. We propose the procedures required to carry out the link lifetime prediction method using existing ML techniques. The tactic creates datasets with the features the models need to learn and be trained. The SVR and XGBoost algorithms that were selected as part of the assessment process were trained. To make the prediction using the trained models, we modified the lifespan prediction function from an offloading approach. To determine the viability of applying link lifespan predictions from the models trained in the road and urban scenarios, we conducted a performance study. The findings indicate that compared to the conventional prediction strategy described in the literature, the suggested link lifetime prediction via regression approaches decreases prediction error rates. An offloading method from the literature is extended by the selected SVR. The task loss and recovery rates might be significantly reduced using the SVR. XGBoost outperformed its ML competitors in task recovery or drop rate by 70% to 80% in an assessed hypothesis compared to an offloading choice technique in the literature. With greater offloading rates from an application on the VANET, this effort is intended to give better efficiency in estimating this data using machine learning in various vehicular settings.

Measuring Acetabular Version after Total Hip Arthroplasty: A Comparison of Two Radiographic Methods.

Objective The objective of the present work was to compare the measurement of acetabular component version on anteroposterior (AP) and on cross-table radiographs after total hip arthroplasty (THA). Methods Radiographs of 60 hips with a primary THA were selected. Version was calculated on the AP radiograph using the Lewinnek method and, on the cross-table, using the Woo and Morrey direct method. Results Mean and standard deviation (SD) were different on both radiographs, being 9.7° ± 5.5° on the AP, whereas in the cross-table the measurements were 20.6° ± 8.4° ( p < 0.001). Minding our aim of 10°, the cross-table measurements were statistically different from it ( p < 0.001), while the AP measurement did not differ ( p = 0.716). Conclusion The present study showed that the best way to correctly evaluate the acetabular component positioning following a THA is by measuring anteversion and abduction on an AP radiograph after confirming, in a cross-table radiograph, that the component is not retroverted.

Measuring Acetabular Version after Total Hip Arthroplasty: A Comparison of Two Radiographic Methods / Medição da versão acetabular após artroplastia total do quadril: Comparação de dois métodos radiográficos

Abstract Objective The objective of the present work was to compare the measurement of acetabular component version on anteroposterior (AP) and on cross-table radiographs after total hip arthroplasty (THA). Methods Radiographs of 60 hips with a primary THA were selected. Version was calculated on the AP radiograph using the Lewinnek method and, on the cross-table, using the Woo and Morrey direct method. Results Mean and standard deviation (SD) were different on both radiographs, being 9.7° ± 5.5° on the AP, whereas in the cross-table the measurements were 20.6° ± 8.4° (p < 0.001). Minding our aim of 10°, the cross-table measurements were statistically different from it (p < 0.001), while the AP measurement did not differ (p = 0.716). Conclusion The present study showed that the best way to correctly evaluate the acetabular component positioning following a THA is by measuring anteversion and abduction on an AP radiograph after confirming, in a cross-table radiograph, that the component is not retroverted.

Resumo Objetivo O objetivo do presente trabalho foi comparar a medição da versão do componente acetabular em radiografias em incidência anteroposterior (AP) e crosstable após artroplastia total do quadril (ATQ). Métodos Foram selecionadas radiografias de 60 quadris com ATQ primário. A versão foi calculada na radiografia AP usando o método de Lewinnek e, na cross-table, usando o método direto do Woo e Morrey. Resultados A média e o desvio padrão (DP) foram diferentes em ambas as radiografias, sendo 9,7° ± 5,5° no AP, enquanto na cross-table foram 20,6° ± 8,4° (p < 0,001). Considerando nosso objetivo de 10°, as medidas da cross-table foram estatisticamente diferentes dele (p < 0,001), enquanto a medição AP não diferiu (p = 0,716). Conclusão O presente estudo mostrou que a melhor maneira de avaliar corretamente o posicionamento do componente acetabular após uma ATQ é medindo a anteversão e a abdução em uma radiografia AP após confirmar, em uma radiografia cross-table, que o componente não é retrovertido.

The Lisbon Agreement on femoroacetabular impingement imaging-part 2: general issues, parameters, and reporting.

OBJECTIVES: Imaging assessment for the clinical management of femoroacetabular impingement (FAI) is controversial because of a paucity of evidence-based guidance and notable variability among practitioners. Hence, expert consensus is needed because standardised imaging assessment is critical for clinical practice and research. We aimed to establish expert-based statements on FAI imaging by using formal methods of consensus building. METHODS: The Delphi method was used to formally derive consensus among 30 panel members from 13 countries. Forty-four questions were agreed upon, and relevant seminal literature was circulated and classified in major topics to produce answering statements. The level of evidence was noted for all statements, and panel members were asked to score their level of agreement (0-10). This is the second part of a three-part consensus series and focuses on 'General issues' and 'Parameters and reporting'. RESULTS: Forty-seven statements were generated and group consensus was reached for 45. Twenty-five statements pertaining to 'General issues' (9 addressing diagnosis, differential diagnosis, and postoperative imaging) and 'Parameters and reporting' (16 addressing femoral/acetabular parameters) were produced. CONCLUSIONS: The available evidence was reviewed critically, recommended criteria for diagnostic imaging highlighted, and the roles/values of different imaging parameters assessed. Radiographic evaluation (AP pelvis and a Dunn 45° view) is the cornerstone of hip-imaging assessment and the minimum imaging study that should be performed when evaluating adult patients for FAI. In most cases, cross-sectional imaging is warranted because MRI is the 'gold standard' imaging modality for the comprehensive evaluation, differential diagnosis assessment, and FAI surgical planning. KEY POINTS: • Diagnostic imaging for FAI is not standardised due to scarce evidence-based guidance on which imaging modalities and diagnostic criteria/parameters should be used. • Radiographic evaluation is the cornerstone of hip assessment and the minimum study that should be performed when assessing suspected FAI. Cross-sectional imaging is justified in most cases because MRI is the 'gold standard' modality for comprehensive FAI evaluation. • For acetabular morphology, coverage (Wiberg's angle and acetabular index) and version (crossover, posterior wall, and ischial spine signs) should be assessed routinely. On the femoral side, the head-neck junction morphology (α° and offset), neck morphology (NSA), and torsion should be assessed.

The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 3: imaging techniques.

OBJECTIVES: Imaging diagnosis of femoroacetabular impingement (FAI) remains controversial due to a lack of high-level evidence, leading to significant variability in patient management. Optimizing protocols and technical details is essential in FAI imaging, although challenging in clinical practice. The purpose of this agreement is to establish expert-based statements on FAI imaging, using formal consensus techniques driven by relevant literature review. Recommendations on the selection and use of imaging techniques for FAI assessment, as well as guidance on relevant radiographic and MRI classifications, are provided. METHODS: The Delphi method was used to assess agreement and derive consensus among 30 panel members (musculoskeletal radiologists and orthopedic surgeons). Forty-four questions were agreed on and classified into five major topics and recent relevant literature was circulated, in order to produce answering statements. The level of evidence was assessed for all statements and panel members scored their level of agreement with each statement during 4 Delphi rounds. Either "group consensus," "group agreement," or "no agreement" was achieved. RESULTS: Forty-seven statements were generated and group consensus was reached for 45. Twenty-two statements pertaining to "Imaging techniques" were generated. Eight statements on "Radiographic assessment" and 12 statements on "MRI evaluation" gained consensus. No agreement was reached for the 2 "Ultrasound" related statements. CONCLUSION: The first international consensus on FAI imaging was developed. Researchers and clinicians working with FAI and hip-related pain may use these recommendations to guide, develop, and implement comprehensive, evidence-based imaging protocols and classifications. KEY POINTS: • Radiographic evaluation is recommended for the initial assessment of FAI, while MRI with a dedicated protocol is the gold standard imaging technique for the comprehensive evaluation of this condition. • The MRI protocol for FAI evaluation should include unilateral small FOV with radial imaging, femoral torsion assessment, and a fluid sensitive sequence covering the whole pelvis. • The definite role of other imaging methods in FAI, such as ultrasound or CT, is still not well defined.

Femoral neck osteotomy in skeletally mature patients: surgical technique and midterm results.

PURPOSE: Using an extended retinacular flap containing the blood supply for the femoral head, proximal femur osteotomies can be performed at the neck level increasing the potential of correction of complex morphologies. The aim of this study was to analyze the safety, clinical, and radiographic results of this intra-articular surgical technique performed in skeletally mature patients with a minimum follow-up of three years. METHODS: Fourteen symptomatic adult patients (16 hips) with a mean age of 26 years underwent FNO using surgical hip dislocation and an extended soft tissue flap. Radiographs and radial magnetic resonance imaging (MRI) were obtained before and after surgery to evaluate articular congruency, cartilage damage, and morphologic parameters. Clinical functional evaluation was done using the Nonarthritic Hip Score (NAHS), the Hip Outcome Score (HOS), and the modified Harris Hip Score (mHHS). RESULTS: After surgery, no avascular necrosis was observed, and all the osteotomies healed without complication. The initial neck/shaft angle (range 120 to 150°) improved in all cases to a mean value of 130° ± 4.6 (p < 0.001). In eight of nine valgus hips, the high-positioned fovea capitis changed to a normal position after surgery. The NAHS score improved from a mean of 36.5 ± 14.9 to 82.9 ± 13.9 points after surgery (p < 0.001). After surgery, the mean HOS was 87.1 ± 17.6 points, and the mean mHHS was 78.6 ± 17 points. CONCLUSIONS: In this series, femoral neck osteotomy in the adult, although technically more demanding compared with other classic osteotomies, can be considered a safe procedure with considerable potential to correct hip deformities.

Advances in FAI Imaging: a Focused Review.

PURPOSE OF REVIEW: Femoroacetabular impingement (FAI) is one of the main causes of hip pain in young adults and poses clinical challenges which have placed it at the forefront of imaging and orthopedics. Diagnostic hip imaging has dramatically changed in the past years, with the arrival of new imaging techniques and the development of magnetic resonance imaging (MRI). This article reviews the current state-of-the-art clinical routine of individuals with suspected FAI, limitations, and future directions that show promise in the field of musculoskeletal research and are likely to reshape hip imaging in the coming years. RECENT FINDINGS: The largely unknown natural disease course, especially in hips with FAI syndrome and those with asymptomatic abnormal morphologies, continues to be a problem as far as diagnosis, treatment, and prognosis are concerned. There has been a paradigm shift in recent years from bone and soft tissue morphological analysis towards the tentative development of quantitative approaches, biochemical cartilage evaluation, dynamic assessment techniques and, finally, integration of artificial intelligence (AI)/deep learning systems. Imaging, AI, and hip preserving care will continue to evolve with new problems and greater challenges. The increasing number of analytic parameters describing the hip joint, as well as new sophisticated MRI and imaging analysis, have carried practitioners beyond simplistic classifications. Reliable evidence-based guidelines, beyond differentiation into pure instability or impingement, are paramount to refine the diagnostic algorithm and define treatment indications and prognosis. Nevertheless, the boundaries of morphological, functional, and AI-aided hip assessment are gradually being pushed to new frontiers as the role of musculoskeletal imaging is rapidly evolving.

Correction to: The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 1: overview.

The original version of this article, published on 14 May 2020, unfortunately contained a mistake.

The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 1: overview.

OBJECTIVES: Imaging assessment for the clinical management of femoroacetabular impingement (FAI) syndrome remains controversial because of a paucity of evidence-based guidance and notable variability in clinical practice, ultimately requiring expert consensus. The purpose of this agreement is to establish expert-based statements on FAI imaging, using formal techniques of consensus building. METHODS: A validated Delphi method and peer-reviewed literature were used to formally derive consensus among 30 panel members (21 musculoskeletal radiologists and 9 orthopaedic surgeons) from 13 countries. Forty-four questions were agreed on, and recent relevant seminal literature was circulated and classified in five major topics ('General issues', 'Parameters and reporting', 'Radiographic assessment', 'MRI' and 'Ultrasound') in order to produce answering statements. The level of evidence was noted for all statements, and panel members were asked to score their level of agreement with each statement (0 to 10) during iterative rounds. Either 'consensus', 'agreement' or 'no agreement' was achieved. RESULTS: Forty-seven statements were generated, and group consensus was reached for 45 (95.7%). Seventeen of these statements were selected as most important for dissemination in advance. There was no agreement for the two statements pertaining to 'Ultrasound'. CONCLUSION: Radiographic evaluation is the cornerstone of hip evaluation. An anteroposterior pelvis radiograph and a Dunn 45° view are recommended for the initial assessment of FAI although MRI with a dedicated protocol is the gold standard imaging technique in this setting. The resulting consensus can serve as a tool to reduce variability in clinical practices and guide further research for the clinical management of FAI. KEY POINTS: • FAI imaging literature is extensive although often of low level of evidence. • Radiographic evaluation with a reproducible technique is the cornerstone of hip imaging assessment. • MRI with a dedicated protocol is the gold standard imaging technique for FAI assessment.

Reverse Total Shoulder Arthroplasty for Treatment of 3- and 4-Part Proximal Humeral Fractures: Clinical and Radiological Analysis With Minimum Follow-Up of 2 Years.

BACKGROUND: Hemiarthroplasty has been associated with inferior and unpredictable outcomes when used in the treatment of complex proximal humeral fractures in elderly patients. In this age-group, reverse shoulder arthroplasty is gaining popularity due to the promising results presented in recent evidence. Our aim is to analyze the cases of complex proximal humeral fractures treated by reverse shoulder arthroplasty, regarding functional results and complications. MATERIALS AND METHODS: Thirty-five fractures from 33 patients with the mean age of 73.5 (65-81) years were treated with reverse shoulder arthroplasty for complex fractures of the proximal humerus. These patients were followed for a mean of 38.3 months (24-68) and analyzed regarding clinical outcomes and complications. RESULTS: The average Quick-Disabilities of the Arm, Shoulder and Hand and American Shoulder and Elbow Surgeons scores were 6.8 points and 78.3%, respectively. The mean Constant score on the affected side was 64.4 points, 19.5% less than the nonoperated side. The mean active elevation was 123°, abduction 109°, external rotation 38°, and internal rotation 41°. The radiographic tuberosity healing rate was 85.7%. There were no significant differences in outcomes, between patient with healed and reabsorbed tuberosities. Inferior scapular notching was seen in 8 patients. The global complication rate was 12.8%. CONCLUSION: Reverse shoulder arthroplasty yields good and reproductive results with acceptable complication rates in selected elderly patients with complex proximal humeral fractures.

Femoroacetabular Impingement: What the Surgeon Wants to Know.

Femoroacetabular impingement (FAI) is increasingly recognized as a risk factor for early hip degeneration in young active patients. The diagnosis depends on clinical examination and proper imaging that should be able to identify abnormal and sometimes subtle morphological changes. Labral tears and cartilage lesions rarely occur without underlying bone abnormalities. Surgical approaches to treat FAI are increasing significantly worldwide, even without a clearly defined consensus of what should be accepted as the standard imaging diagnosis for FAI morphology.Hip abnormalities encompass many variations related to the shape, size, and spatial orientation of both sides of the joint and can be difficult to characterize if adequate imaging is not available.This article presents a comprehensive review about the information orthopaedic surgeons need to know from radiologists to plan the most rational approach to a painful hip resulting from a mechanical abnormality.

Can We Discriminate Symptomatic Hip Patients From Asymptomatic Volunteers Based on Anatomic Predictors? A 3-Dimensional Magnetic Resonance Study on Cam, Pincer, and Spinopelvic Parameters.

BACKGROUND: Given the high prevalence of patients with hip deformities and no ongoing hip dysfunction, understanding the anatomic factors predicting the symptomatic state is critical. One such variable is how the spinopelvic parameters (SPPs) may interplay with hip anatomic factors. HYPOTHESIS/PURPOSE: SPPs and femoral- and acetabular-specific parameters may predict which patients will become symptomatic. The purpose was to determine which anatomic characteristics with specific cutoffs were associated with hip symptom development and how these parameters relate to each other. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 2. METHODS: 548 participants were designated either symptomatic patients (n = 176, scheduled for surgery with hip pain and/or functional limitation) or asymptomatic volunteers (n = 372, no pain) and underwent 3-dimensional magnetic resonance imaging. Multiple femoral (α angle, Ω angle, neck angle, torsion), acetabular (version, coverage), and spinopelvic (pelvic tilt, sacral slope [SS], pelvic incidence) parameters were measured semiautomatically. Normative values, optimal differentiating thresholds, and a logistic regression analysis were computed. RESULTS: Symptomatic patients had larger cam deformities (defined by increased Ω angle and α angle), smaller acetabular coverage, and larger pelvic incidence and SS angles compared with the asymptomatic volunteers. Discriminant receiver operating characteristic analysis confirmed that radial 2-o'clock α angle (threshold 58°-60°, sensitivity 75%-60%, specificity 80%-84%; area under the curve [AUC] = 0.831), Ω angle (threshold 43°, sensitivity 72%, specificity 70%; AUC = 0.830), acetabular inclination (threshold 6°, sensitivity 65%, specificity 70%; AUC = 0.709), and SS (threshold 44°, sensitivity 72%, specificity 75%; AUC = 0.801) ( P < .005) were the best parameters to classify participants. When parameters were entered into a logistic regression, significant positive predictors for the symptomatic patients were achieved for SS, acetabular inclination, Ω angle, and α angle at 2-o'clock, correctly classifying 85% of cases (model sensitivity 72%, specificity 91%; AUC = 0.919). CONCLUSION: Complex dynamic interplay exists between the hip and SPPs. A cam deformity, acetabular undercoverage, and increased SPP angles are predictive of a hip symptomatic state. SPPs were significant to discriminate between participants and were important in combination with other hip deformities. Symptomatic patients can be effectively differentiated from asymptomatic volunteers based on predictive anatomic factors.

Arthroscopic versus open treatment of cam-type femoro-acetabular impingement: retrospective cohort clinical study.

PURPOSE: The purpose of this study was to determine if there were significant differences between patients submitted to hip arthroscopy (HA) and surgical hip dislocation (SHD) to treat femoro-acetabular impingement (FAI), which variables were significantly associated with hip function before surgery and those predictive of the applied functional outcome scale and its variation rate after surgery. METHODS: We selected 198 patients treated with HA or SHD with a mean follow-up of 59 months. Inclusion criteria were ages 18-50 years, isolated FAI cam morphology and complete clinical and radiologic documentation. The subjective outcome measure used was the nonarthritic hip score (NAHS). We compared pre-operative and post-operative NAHS, alpha angles and complication rates. Multiple linear regression analyses were performed to find which variables could influence NAHS values. RESULTS: The mean alpha-angle value improved from 71.5° to 40.8°, and mean NAHS improved from 50 to 83 points, with no difference between groups (HA/SHD). We found only a 16.9% influence rate on the pre-operative score, explained by variables of gender/pre-operative alpha angle and presence of degenerative changes/age. The influence rate on the NAHS variation ratio after surgery was 62.8%, explained by the variables of pre-operative score, type of surgery and type of surgery/alpha angle. The complication rate was 7%. CONCLUSIONS: FAI surgery can be considered effective in improving patient symptoms. There were no differences in clinical or radiographic results between techniques. We could more accurately predict the variation ratio of NAHS after surgery than its pre-operative value.

Valgus Slipped Capital Femoral Epiphysis: Pathophysiology of Motion and Results of Intracapsular Realignment.

OBJECTIVES: The purpose of this study was to report (1) a different but specific pattern of impingement in hips involved with valgus slipped capital femoral epiphysis (valgus SCFE) and (2) the results of surgical treatment using intracapsular realignment techniques. DESIGN: Case series. SETTING: Multiple academic centers. PATIENTS: Six patients with 8 involved hips referred for valgus alignment of proximal femoral epiphysis (valgus SCFE). INTERVENTION: Intracapsular realignment osteotomy combined with periacetabular osteotomy if needed. MAIN OUTCOME MEASUREMENT: The clinical and radiographical results and pathophysiology of motion. RESULTS: Eight hips in 6 patients were treated with subcapital (5 hips) or femoral neck (3 hips) osteotomy for realignment. The medially prominent metaphysis created an inclusive impingement at the anterior acetabular wall, whereas the high coxa valga favored impacting impingement at the posterior head-neck junction. The mean preoperative epiphyseal-shaft angle of 110.5 (range 90-125 degrees) was reduced to 62 degrees (range 55-70 degrees) postoperatively. At the last follow-up, all but 1 hip were pain-free and impingement-free, with normal range of motion. One hip was replaced after repeated attempts of correction. The overall hip functional result using modified Merle d'Aubigne scoring system was excellent in 5 hips (18-16 points), good in 2 hips (16-15 points), and poor in 1 hip (6 points). CONCLUSIONS: Impingement in valgus SCFE deformity is specific and complex. Anatomical realignment can lead to favorable results by the restoration of normal morphology and impingement-free range of motion. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Hip shape is symmetric, non-dependent on limb dominance and gender-specific: implications for femoroacetabular impingement. A 3D CT analysis in asymptomatic subjects.

OBJECTIVE: To determine the reference intervals (RefInt) of the quantitative morphometric parameters of femoroacetabular impingement (FAI) in asymptomatic hips with computed tomography (CT) and determine their dependence on age, side, limb dominance and sex. METHODS: We prospectively included 590 patients and evaluated 1111 hips with semi-automated CT analysis. We calculated overall, side- and sex-specific parameters for imaging signs of cam [omega and alpha angle (α°)] and pincer-type morphology [acetabular version (ACvers), lateral centre-edge angle (LCEA) and cranio-caudal coverage]. RESULTS: Hip shape was symmetrical and did not depend on limb dominance. The 95% RefInt limits were sex-different for all cam-type parameters and extended beyond current abnormal thresholds. Specifically, the upper limits of RefInt for α° at 12:00, 1:30 and 3:00 o'clock positions were 56°, 70° and 58°, respectively, and 45° for LCEA. Acetabular morphology varied between age groups, with a trend toward an LCEA/ACvers increase over time. CONCLUSION: Our morphometric measurements can be used to estimate normal hip morphology in asymptomatic individuals. Notably they extended beyond current thresholds used for FAI imaging diagnosis, which was most pronounced for cam-type parameters. We suggest the need to reassess α° RefInt and consider a 60° threshold for the 12:00/3:00 positions and 65-70° for other antero-superior positions. KEY POINTS: • Hip shape is symmetrical regardless of limb dominance. • Pincer/cam morphology is frequent in asymptomatic subjects (20 and 71%, respectively). • LCEA and acetabular version increases with age (5-7° between opposite age groups). • Femoral morphology is stable after physeal closure (in the absence of pathology). • Alpha and omega angle thresholds should be set according to sex.

Clinical rating scale for pantothenate kinase-associated neurodegeneration: A pilot study.

BACKGROUND: Pantothenate kinase-associated neurodegeneration is a progressive neurological disorder occurring in both childhood and adulthood. The objective of this study was to design and pilot-test a disease-specific clinical rating scale for the assessment of patients with pantothenate kinase-associated neurodegeneration. METHODS: In this international cross-sectional study, patients were examined at the referral centers following a standardized protocol. The motor examination was filmed, allowing 3 independent specialists in movement disorders to analyze 28 patients for interrater reliability assessment. The scale included 34 items (maximal score, 135) encompassing 6 subscales for cognition, behavior, disability, parkinsonism, dystonia, and other neurological signs. RESULTS: Forty-seven genetically confirmed patients (30 ± 17 years; range, 6-77 years) were examined with the scale (mean score, 62 ± 21; range, 20-106). Dystonia with prominent cranial involvement and atypical parkinsonian features were present in all patients. Other common signs were cognitive impairment, psychiatric features, and slow and hypometric saccades. Dystonia, parkinsonism, and other neurological features had a moderate to strong correlation with disability. The scale showed good internal consistency for the total scale (Cronbach's α = 0.87). On interrater analysis, weighted kappa values (0.30-0.93) showed substantial or excellent agreement in 85% of the items. The scale also discriminated a subgroup of homozygous c.1583C>T patients with lower scores, supporting construct validity for the scale. CONCLUSIONS: The proposed scale seems to be a reliable and valid instrument for the assessment of pediatric and adult patients with pantothenate kinase-associated neurodegeneration. Additional validation studies with a larger sample size will be required to confirm the present results and to complete the scale validation testing. © 2017 International Parkinson and Movement Disorder Society.

Arterial Topographic Anatomy Near the Femoral Head-Neck Perforation with Surgical Relevance.

BACKGROUND: Knowledge of the vascular supply of the femoral head is crucial for hip-preserving surgical procedures. The critical area for reshaping cam deformity is at the retinacular vessel penetration, an area with ill-defined topographic anatomy. We performed a cadaver study of the extension of the lateral retinaculum near the head-neck junction, distribution of the arterial vascular foramina, and initial intracapital course of these vessels. METHODS: In 16 fresh proximal parts of the femur without head-neck deformities, the deep branch of the medial femoral circumflex artery was injected with gadolinium for magnetic resonance imaging (MRI) sequences to identify arterial structures. RESULTS: We found a mean number of 4.5 arterial foramina, showing a predominance from 10 to 12 o'clock. The retinaculum extended 20 mm from 1 to 10 o'clock. The surface distance from the cartilage border to the vascular foramina under the synovial fold was 6.5 mm, and the depth from the same cartilage border to the initial intraosseous vessel pathways was 5.3 mm. CONCLUSIONS: The data add further precision to the arterial topography at the retinacular foramina, an area that is crucial for the perfusion of the femoral head. It may overlap with the area of anterolateral cam deformity and plays a role in choosing the cuts for subcapital and intracapital osteotomies. CLINICAL RELEVANCE: The information is taken from normal hips and may not be directly applicable to the deformed hip. Nevertheless, it is a prerequisite for a surgeon to understand the normal anatomy and use those boundaries to prevent mistakes during intra-articular joint-preserving hip surgical procedures.

On the utility of 3D hand cursors to explore medical volume datasets with a touchless interface.

Analyzing medical volume datasets requires interactive visualization so that users can extract anatomo-physiological information in real-time. Conventional volume rendering systems rely on 2D input devices, such as mice and keyboards, which are known to hamper 3D analysis as users often struggle to obtain the desired orientation that is only achieved after several attempts. In this paper, we address which 3D analysis tools are better performed with 3D hand cursors operating on a touchless interface comparatively to a 2D input devices running on a conventional WIMP interface. The main goals of this paper are to explore the capabilities of (simple) hand gestures to facilitate sterile manipulation of 3D medical data on a touchless interface, without resorting on wearables, and to evaluate the surgical feasibility of the proposed interface next to senior surgeons (N=5) and interns (N=2). To this end, we developed a touchless interface controlled via hand gestures and body postures to rapidly rotate and position medical volume images in three-dimensions, where each hand acts as an interactive 3D cursor. User studies were conducted with laypeople, while informal evaluation sessions were carried with senior surgeons, radiologists and professional biomedical engineers. Results demonstrate its usability as the proposed touchless interface improves spatial awareness and a more fluent interaction with the 3D volume than with traditional 2D input devices, as it requires lesser number of attempts to achieve the desired orientation by avoiding the composition of several cumulative rotations, which is typically necessary in WIMP interfaces. However, tasks requiring precision such as clipping plane visualization and tagging are best performed with mouse-based systems due to noise, incorrect gestures detection and problems in skeleton tracking that need to be addressed before tests in real medical environments might be performed.

Recommendations to Reduce Risk of Nerve Injury During Bernese Periacetabular Osteotomy (PAO).

The Bernese periacetabular osteotomy (PAO) is a widely used procedure to reorient a dysplastic acetabulum resulting from developmental dysplasia of the hip, retroversion, protrusio, or some deformities with a traumatic etiology. Throughout the execution, the lateral femoral cutaneous nerve (LFCN) as well as the obturator, femoral, and sciatic nerves can be injured. Injury to 1 of the 3 major nerves is a devastating event for the patient followed by an ill-defined period of hope for nerve recovery and fear of lifelong disability. Surgical experience is an essential factor in reducing the prevalence of nerve injury, whereas proof of the value of intraoperative fluoroscopy and nerve monitoring still must be established. Although it is known that, for example, the ischial cuts of the complex osteotomy place the sciatic nerve at risk, the action causing the nerve injury is rarely clear in the individual situation. The literature has been mostly limited to reports of incidence and offers little analytic information. Through the use of cadaveric dissections, we visualized the possible impacts of the different steps of the procedure on the nerves in their anatomic vicinity, and the present report demonstrates how nerves can be protected with retractor positioning and how lower-limb positioning can lead to nerve relaxation, an important means to avoid mechanical injury. While the frequent injuries of the LFCN are exclusively related to the approach, sciatic nerve injuries are mainly the result of the ischial osteotomy steps and femoral nerve injuries are seen nearly exclusively with the correction of the acetabular fragment. The authors implemented the demonstrated measures for 9 years, during which approximately 800 periacetabular osteotomies resulted in a total of 2 femoral and 2 sciatic nerve lesions-or a nerve injury rate of 0.5%. The nerves injuries resolved within 6 to 9 months in 3 hips, and 1 patient had a definitive foot drop requiring a splint at the time of writing.