Threshold for anterior acetabular component overhang correlated with symptomatic iliopsoas impingement after total hip arthroplasty.

Aims: Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA. Methods: We analyzed the CT scans of 622 patients (758 THAs) between May 2011 and May 2020. From this population, we identified 136 patients with symptoms suggestive of IP impingement. Among them, six were subsequently excluded: three because the diagnosis was refuted intraoperatively, and three because they had another obvious cause of impingement, leaving 130 hips (130 patients) in the study (impingement) group. They were matched to a control group of 138 asymptomatic hips (138 patients) after THA. The anterior acetabular component overhang was measured on an axial CT slice based on anatomical landmarks (orthogonal to the pelvic axis). Results: The impingement group had a median overhang of 8 mm (interquartile range (IQR) 5 to 11) versus 0 mm (IQR 0 to 4) for the control group (p < 0.001). Using receiver operating characteristic curves, an overhang threshold of 4 mm was best correlated with a diagnosis of impingement (sensitivity 79%, specificity 85%; positive predictive value 75%, negative predictive value 85%). Conclusion: Pain after THA related to IP impingement can be reasonably linked to acetabular overhang if it exceeds 4 mm on a CT scan. Below this threshold, it seems logical to look for another cause of IP irritation or another reason for the pain after THA before concluding that impingement is present.

Corona mortis and pelvic dissection: Understanding the relationship between anatomical structures and bone areas.

Pelvic fractures are becoming increasingly frequent. The gold standard for surgical managements remains open procedures. Despite its excellent biomechanically results, it can lead to many complications. Minimally invasive surgery could reduce these complications. For complex pelvic trauma, extraperitoneal endoscopic technique has never been described. The aim of this study is to determine anatomical landmarks which are useful for endoscopic pelvic ring surgery using an extraperitoneal approach. The second objective is to compare this minimally invasive procedure to expose the bone versus a traditional open approach. After preparing the vessels with latex injections, 10 specimens are dissected alternately, using an endoscopic method (MIS) on one side and an open method on the other side. Both procedures are performed on the same subject. The visualized bone areas are drilled with burr holes. The marked surfaces are measured with photogrammetry. Finally, the data are processed (surface analysis). An extraperitoneal endoscopic dissection that follows anatomical landmarks can be performed. Bone area (mm2 ) visualized by endoscopy was 74 ± 14 (59-94) compared to 71 ± 16 (48-94) by open method. Paired t-test was performed with no significant difference between the two methods. Skin and muscular incisions were significantly lower in the MIS group (5.1, IC95% [4.1; 6.1], p < 0.001). An extraperitoneal endoscopic dissection of the pelvis can be performed. We also find no significant difference between our method and an open traditional approach concerning bone exposure. We offer a holistic approach to treat pelvic fractures by identifying key anatomical structures.

Commercially-available AI algorithm improves radiologists' sensitivity for wrist and hand fracture detection on X-ray, compared to a CT-based ground truth.

OBJECTIVES: Algorithms for fracture detection are spreading in clinical practice, but the use of X-ray-only ground truth can induce bias in their evaluation. This study assessed radiologists' performances to detect wrist and hand fractures on radiographs, using a commercially-available algorithm, compared to a computerized tomography (CT) ground truth. METHODS: Post-traumatic hand and wrist CT and concomitant X-ray examinations were retrospectively gathered. Radiographs were labeled based on CT findings. The dataset was composed of 296 consecutive cases: 118 normal (39.9%), 178 pathological (60.1%) with a total of 267 fractures visible in CT. Twenty-three radiologists with various levels of experience reviewed all radiographs without AI, then using it, blinded towards CT results. RESULTS: Using AI improved radiologists' sensitivity (Se, 0.658 to 0.703, p < 0.0001) and negative predictive value (NPV, 0.585 to 0.618, p < 0.0001), without affecting their specificity (Sp, 0.885 vs 0.891, p = 0.91) or positive predictive value (PPV, 0.887 vs 0.899, p = 0.08). On the radiographic dataset, based on the CT ground truth, stand-alone AI performances were 0.771 (Se), 0.898 (Sp), 0.684 (NPV), 0.915 (PPV), and 0.764 (AUROC) which were lower than previously reported, suggesting a potential underestimation of the number of missed fractures in the AI literature. CONCLUSIONS: AI enabled radiologists to improve their sensitivity and negative predictive value for wrist and hand fracture detection on radiographs, without affecting their specificity or positive predictive value, compared to a CT-based ground truth. Using CT as gold standard for X-ray labels is innovative, leading to algorithm performance poorer than reported elsewhere, but probably closer to clinical reality. CLINICAL RELEVANCE STATEMENT: Using an AI algorithm significantly improved radiologists' sensitivity and negative predictive value in detecting wrist and hand fractures on radiographs, with ground truth labels based on CT findings. KEY POINTS: • Using CT as a ground truth for labeling X-rays is new in AI literature, and led to algorithm performance significantly poorer than reported elsewhere (AUROC: 0.764), but probably closer to clinical reality. • AI enabled radiologists to significantly improve their sensitivity (+ 4.5%) and negative predictive value (+ 3.3%) for the detection of wrist and hand fractures on X-rays. • There was no significant change in terms of specificity or positive predictive value.

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.

Crystal Diseases of the Spine.

Gout, calcium pyrophosphate deposition disease, and apatite calcifications, the three main crystal disorders, may involve the spine. These disorders can be completely asymptomatic or associated with various clinical symptoms, such as acute flares and more chronic manifestations. This article presents the typical and more unusual imaging features encountered in these disorders.

Evaluation of the socioprofessional consequences of thoracic outlet syndrome.

PURPOSE: Thoracic outlet syndrome (TOS) is a ductal syndrome that can have a significant functional impact. Various studies have highlighted positional factors and repetitive movements as risk factors for the development of TOS. However, there are few literature data on the socioprofessional consequences of TOS. METHODS: We performed a prospective, cross-sectional, descriptive, multicentre study of workers having received a Doppler ultrasound diagnosis of TOS between December 17th, 2018, and March 16th, 2021. Immediately after their diagnosis, patients completed a self-questionnaire on the impact of TOS on their work activities. We assessed the frequency of TOS-related difficulties at work and the associated socioprofessional consequences. Trial Registration Number (TRN) is NCT03780647 and date of registration December 18, 2018. RESULTS: Eighty-two participants (95.3%) reported difficulties at work. Seventy-seven of the participants with difficulties (94%) worked in the tertiary sector; these difficulties were due to prolonged maintenance of a posture, carrying loads, and repetitive movements. Although the majority of participants experienced organizational problems and lacked support at work, few of them had approached support organizations, expert and/or healthcare professionals. CONCLUSIONS: TOS was almost always associated with difficulties at work (95.3%). However, poor awareness of sources of help or a perceived lack of need may discourage people with TOS from taking steps to resolve these difficulties. It is clear that the socioprofessional management of TOS requires significant improvements.

Study of Root Transparency in Different Postmortem Intervals Using Scanning Electron Microscopy.

In the fields of forensics, the identification of human remains is a recurrent problem. The estimated age at death is one of the copious criteria to be evaluated. In adult teeth, the height of the root dentin transparency is used to estimate age. However, in archaeological material, this phenomenon appears inconstant. The aim of this work was to observe the structural modifications of the sclerotic dentin in the teeth for different postmortem intervals. The study included two parts (retrospective and prospective study) with 21 human monoradicular teeth, from bodies donated to medical science with postmortem intervals (PMIs) of 0, 1, 2 and 5 years and archeological excavation. After inclusion based on resin, section and polishing, the samples were analyzed with a scanning electron microscope (SEM) JSM-7800F®, and the procedure was completed via a semiquantitative analysis of calcium and phosphorus using EDX microanalysis. The analysis showed the existence of tubular and chemical modifications of sclerotic dentin at different PMIs. Our SEM study allowed us to observe a difference in tubule aspects linked to an increased PMI: the loss of peritubular collar and the lumen obstruction of tubules with a hyperdense material. Microanalysis highlighted variations in phosphocalcic ratios among the different groups, especially in the pulp area and the canine. Our hypotheses that explain these differences are based on the postmortem modifications of the crystals of the mineral phase of sclerotic dentin under the influence of chemical and/or bacterial action.

Metaphyseal and Diaphyseal Contours: Variants and Pitfalls.

We discuss several variants of the metaphyseal and diaphyseal bone surfaces that may be misleading in clinical practice. They include metaphyseal stripes, spiculated metaphyseal cortex, cortical desmoid, laminated lateral supracondylar ridge, cortical vascular canals, variations in shape or lucency of normal tuberosities, cortical thickening of normal ridges, and well-organized undulated hyperostosis at the proximal phalanges.

Anatomical Variants of the Sacroiliac Joint.

Anatomical variants are frequently encountered when assessing the sacroiliac joints (SIJ) using magnetic resonance imaging. When not located in the weight-bearing part of the SIJ, variants associated with structural and edematous changes can be misinterpreted as sacroiliitis. Their correct identification is necessary to avoid radiologic pitfalls. This article reviews five SIJ variants involved in the dorsal ligamentous space (accessory SIJ, iliosacral complex, semicircular defect, bipartite iliac bony plate, and crescent iliac bony plate) and three SIJ variants involved in the cartilaginous part of the SIJ (posterior dysmorphic SIJ, isolated synostosis, and unfused ossification centers).

Anatomical study of the dorsal capsulo-scapholunate septum using high frequency ultrasonography.

INTRODUCTION: The dorsal capsulo-scapholunate septum (DCSS) is a recently described capsuloligamentous structure between the dorsal bundle of the scapholunate ligament (SLL) and the joint capsule of the wrist. It acts a secondary stabilizer of the scapholunate joint. The aim of this study was to evaluate the visibility and normal appearance of DCSS on high frequency ultrasound. HYPOTHESIS: The DCSS can be analyzed using high frequency ultrasound. MATERIALS AND METHODS: Three cadaveric wrists were dissected in order to study the DCSS; one without labeling and the other two after labeling under ultrasound guidance. On two other wrists, a correlation between the structure considered to be the DCSS on ultrasound and the corresponding CT arthrography and anatomical sections was carried out. Finally, sagittal ultrasound sections of the DCSS region on 42 healthy wrists were analyzed retrospectively. RESULTS: During dissection, the DCSS corresponded to a fibrous structure extending to the dorsal surface of the scaphoid and lunate, with certain fibers converging towards the SLL. On high-frequency ultrasound, a hyperechoic fibrillar structure was visualized at the theoretical position of the DCSS. The dissections performed after ultrasound-guided transfixion showed that its limits corresponded to the limits of the DCSS. The anatomical, CT arthrography and ultrasound sections in the DCSS region were concordant. The DCSS was retrospectively visible on at least one reference ultrasound slice in 90.5% of healthy wrists, and was always hyperechoic. Its average thickness was 1.38±0.24mm. DISCUSSION: Our study describes the normal sonographic characteristics of the DCSS, visible in a majority of healthy patients on high-frequency ultrasound. The analysis of the sonographic characteristics of the DCSS in the context of acute wrist trauma should be evaluated, and a diagnostic decision tree has been proposed. LEVEL OF EVIDENCE: IV.

3D printing for orbital volume anatomical measurement.

PURPOSE: The aim was to develop a method for reproducible orbital volume (OV) measurement in vivo based on 3D printing. METHODS: Twelve orbits were obtained from dry skulls of the Human Anatomy Department of Lille University. Computer tomography (CT) slice images of these orbits were transformed into stereo-lithography (STL) format and 3D-printed. Bone openings were closed using either putty and cellophane after printing (3D-Orb-1) or at the printing stage in silico using MeshMixer (3D-Orb-2). The results were compared with those of the conventional water-filling method as a control group (Anat-Orb). RESULTS: The observers reported a mean orbital volume of 21.3 ± 2.1 cm3 for the open-skull method, 21.2 ± 2.4 cm3 for the non-sealed 3D-printing method, and 22.2 ± 2.0 cm3 for the closed-print method. Furthermore, the intraclass correlation coefficients (ICCs) showed excellent intra-rater agreement, i.e., an ICC of 0.994 for the first observer and 0.998 for the second, and excellent interobserver agreement (ICC: 0.969). The control and 3D-Orb-1 groups show excellent agreement (ICC: 0.972). The 3D-Orb-2 exhibits moderate agreement (ICC: 0.855) with the control and appears to overestimate orbital volume slightly. CONCLUSION: Our 3D-printing method provides a standardized and reproducible method for the measurement of orbital volume.

MRI signal and morphological alterations of the suprapatellar fat pad in asymptomatic subjects: are these normal variants?

OBJECTIVE: To study the prevalence of suprapatellar fat pad (SPFP) MR alterations in asymptomatic subjects, in relation to a wide range of clinical/imaging parameters, including muscle performance tests and physical activity data. MATERIALS AND METHODS: We prospectively included 110 asymptomatic subjects as part of a cohort study. Inclusion criteria were no knee pain in the last year. Exclusion criteria were any medical/surgical history of a knee disorder. Subjects underwent knee and low-dose posture radiographs [EOS®], 3 T MRI, clinical examination including muscle performance tests, and physical activity monitoring. The presence/absence of SPFP alterations (hyperintensity and mass effect) were assessed through consensus reading on fluid-sensitive sequences. Differences between groups of knees with SPFP alterations and controls were tested for a total of 55 categorical/continuous clinical/imaging parameters, including SPFP relative-T2-signal, trochlear/patellar/lower-limb morphologic measurements. Wilcoxon-rank-sum and chi-square tests were used to compare groups of patients. The histological correlation was obtained in a cadaveric specimen. RESULTS: SPFP alterations were common in asymptomatic subjects: hyperintensity 57% (63/110) and mass effect 37% (41/110), with 27% (30/110) showing both. Among the 55 imaging, clinical, or activity parameters tested, only increased patellar tilt angle (p = 0.02) and TT-TG distance (p = 0.03) were statistically different between groups of SPFP alterations and controls. The histological correlation showed more abundant connective tissue in SPFP compared to the prefemoral fat pad. CONCLUSIONS: SPFP hyperintensity and mass effect are common MRI findings in asymptomatic knees, and they are not related to most imaging, clinical, and activity parameters. Care should be taken not to overcall them pathological findings as they most likely represent normal variants.

Anatomical study of the sternoclavicular joint using high-frequency ultrasound.

OBJECTIVES: The purpose of the present study was to determine whether ultrasound enables assessment of sternoclavicular structures. METHODS: A preliminary study in 3 cadavers was followed by an ultrasound study, performed by 2 musculoskeletal radiologists working in consensus, in 59 patients without history of trauma, surgery or pain in the sternoclavicular joint. The visibility, echogenicity and thickness of the sternoclavicular structures were assessed. RESULTS: The anterior sternoclavicular ligament and the interclavicular ligament could be seen in all patients (mean thickness: 1.4 mm and 1.3 mm, respectively). The articular disc was clearly seen in 66.1% of cases, and shoulder antepulsion enabled analysis in an additional 20.3%. Intra-articular joint gas was frequent (33.89% of cases), preventing analysis of the disc in 2 patients. Only the superficial anterior aspect of the clavicular and sternal articular cartilages could be assessed. Joint effusion was seen in 6.8% of cases. Clavicular osteophytes, sternal osteophytes and bone irregularities at the anterior sternoclavicular ligament insertion were detected in 33.9%, 16.9% and 16.9% of cases, respectively. CONCLUSION: The anterior sternoclavicular ligament, interclavicular ligament and anterior intra-articular structures can be visualized by ultrasound. This means of assessment may have clinical applications, particularly in patients with trauma or microtrauma.

Presurgical Perspective and Postsurgical Evaluation of Non-Achilles Tendons of the Ankle and Retinaculum.

The vast majority of non-Achilles ankle tendinopathies are related to overuse. This article discusses the clinical aspect, imaging appearance, and management of tendinopathies of the lateral, medial, and the anterior compartments with a focus on presurgical perspective and postsurgical evaluation.

Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance is effective, quick, and safe.

OBJECTIVES: The aim of this study was to assess the feasibility, performance, and complications of a non-surgical, minimally-invasive procedure of deep contraceptive implant removal under continuous ultrasound guidance. METHODS: The ultrasound-guided procedure consisted of local anesthesia using lidocaine chlorhydrate 1% (10 mg/mL) with a 21-G needle, followed by hydrodissection using NaCl 0.9% (9 mg/mL) and implant extraction using a Hartmann grasping microforceps. The parameters studied were the implant localization, success and complication rates, pain throughout the intervention, volumes of lidocaïne and NaCl used, duration of the procedure, and size of the incision. Between November 2019 and January 2021, 45 patients were referred to the musculoskeletal radiology department for ultrasound-guided removal of a deep contraceptive implant and were all retrospectively included. RESULTS: All implants were successfully removed en bloc (100%). The mean incision size was 2.7 ± 0.5 mm. The mean duration of the extraction procedure was 7.7 ± 6.3 min. There were no major complications (infection, nerve, or vessel damage). As a minor complication, 21 patients (46.7%) reported a benign superficial skin ecchymosis at the puncture site, spontaneously regressing in less than 1 week. The procedure was very well-tolerated, with low pain rating throughout (1.0 ± 1.5/10 during implant extraction). CONCLUSIONS: Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, effective, and safe. In the present cohort, all implants were successfully removed, whatever the location, with short procedural time, small incision size, low pain levels, and no significant complications. This procedure could become a gold standard in this indication. KEY POINTS: • Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, which led to a success rate of 100% whatever the location (even close to neurovascular structures), with only a small skin incision (2.7 ± 0.5 mm). • The procedure was safe, quick, without any major complications, and very well tolerated in terms of pain. • This minimally invasive ultrasound-guided procedure could become the future gold standard for the removal of deep contraceptive implants, as an alternative to surgical extraction, even for implants in difficult locations such as subfascial ones or those close to neurovascular structures.

Anatomical study of the proximal tibiofibular ligaments using ultrasound.

OBJECTIVES: No description of the proximal tibiofibular (PTF) ligaments by means of high ultrasound has yet been reported in the literature. The purpose of this study was to assess whether ultrasound may allow the assessment of these ligaments. METHODS: This study was initially undertaken in three cadaveric knees, followed by an ultrasound study performed by two musculoskeletal radiologists working in consensus of 52 patients without history of trauma or surgery of the knee, and without lateral knee pain. The visibility, echogenicity, length and thickness of the PTF ligaments were assessed. RESULTS: Regarding the anterior PTF ligament, the superior bundle and the upper and lower middle bundles were clearly seen in 42.3%, 100% and 75% of the knees, respectively. Regarding the posterior PTF ligament, the superior and middle bundles were clearly seen in 88.4% and 51.9% of the knees, respectively. The echo-anatomy of these ligaments and the probe positioning allowing their best depiction were described in this study. CONCLUSION: Most of the PTF ligaments can be visualized by means of ultrasound. This possible assessment may have clinical applications, particularly in patients with lateral knee pain.

Impact of introducing extremity cone-beam CT in an emergency radiology department: A population-based study.

BACKGROUND: Musculoskeletal cone-beam CT (CBCT) recently appeared on the market, with image quality comparable to that of high-resolution CT. It was previously implemented mainly in craniofacial surgery and in orthopedic limb surgery for weight-bearing imaging, but without large-scale assessment in emergency settings. We therefore conducted a retrospective comparative study in an emergency radiology department: 1) to assess whether introduction of CBCT dedicated to extremity traumatology reduced radiation dose delivered to the patient undergoing cross-sectional imaging, 2) to assess whether it increased turnover, and 3) to study the feasibility and practical consequences. Study hypothesis Introducing CBCT dedicated to traumatology in an emergency radiology department reduces radiation dose related to cross-sectional imaging in extremity trauma. PATIENTS AND METHODS: Two periods were distinguished: in May-November 2016, the only cross-sectional imaging available in our emergency radiology department was multi-detector CT (MDCT); in May-November 2017, both MDCT and CBCT were available. Thus, the population in period 1 (n=165) had undergone only MDCT extremity imaging, while patients in period 2 underwent either CBCT (n=139) or MDCT (n=85). Study parameters notably included dose-length product (DLP) and length of patient stay in the radiology department (turnover). RESULTS: Mean DLP was significantly reduced with the introduction of CBCT: 210.3±133.6 mGy.cm (range, 20-595) in period 1, versus 138.4±92.7 mGy.cm (range, 32-623) in period 2 (p<0.0001). Taking both periods together, mean DLP was 50.7% lower with CBCT (n=139) than MDCT (n=249): respectively, 101.6±14.9 mGy.cm (range, 50.6-126.9) versus 206.5±131.8 mGy.cm (range, 20-623) (p<0.0001). Turnover accelerated with the introduction of CBCT, with mean stay of 84.9minutes in period 1 versus 72.1minutes in period 2 (p=0.011). In period 2, turnover was 23.6% faster with CBCT than MDCT: respectively, 64.9minutes versus 85.0minutes (p=0.0004). DISCUSSION: Introducing CBCT dedicated to the extremities in an emergency radiology department was feasible. It reduced overall radiation dose and accelerated turnover. LEVEL OF EVIDENCE: III; comparative case-control study.

Accuracy of non-guided versus ultrasound-guided injections in cervical muscles: a cadaver study.

INTRODUCTION: The col-cap concept encouraged neurologists to inject a large group of muscles in the treatment of cervical dystonia. This includes deep muscles such as the obliquus capitis inferior or the semispinalis capitis, and muscles close to vascular or neurological structures such as scalene muscles. Our aim was to determine the accuracy of injections in cervical muscles using ultrasonography (US) or palpation of anatomical landmarks. METHODS: A mix of paint, gelatin and iodized contrast agent was injected in nine pairs of cervical muscles of human cadavers, according to two injection techniques: US-guided and non-guided. The dye was localized on 1 cm-thick, frozen slices. RESULTS: A total of 102 muscles was injected in the US-guided group (n = 8). The global accuracy was 88.2%. The lowest accuracy was in the OCI (41.7%); trying to avoid the vertebral artery, injections were too medial. A total of 54 muscles was injected in the non-guided group (n = 3). The global accuracy was 48.0%; moreover, some dye was found in four blood vessels. The embalming process produced texture changes, making difficult the palpation of bony landmarks. CONCLUSIONS: Our results indicate that US-guided injections are more accurate than non-guided injections in most cervical muscles.

Enlarged External Occipital Protuberance in young French individuals' head CT: stability in prevalence, size and type between 2011 and 2019.

External Occipital Protuberance (EOP) enlargement has been recently reported to increase in young adults, with a putative link with postural factors such as the use of smartphones. This study aims to analyze finely the changes in prevalence and size of EOP enlargement in millennials, throughout the smartphone era (2011 - 2019). Anonymized head Computerized Tomography (CT) examinations from patients aged 18-30 in 2011 (n = 205) or 2019 (n = 240), were reviewed to assess the type of EOP and to measure its volume in case of enlargement. Additional CT analyses were performed on two ancient skulls, from a XVIth century young male and a young female Egyptian mummy. There was no significant evolution in the prevalence of EOP enlargement between 2011 (92/205, 44.9%) and 2019 (106/240; 44.2%) (P = 0.92). There was no significant evolution either in the distribution of enlarged EOP volumes (P = 0.14) or of EOP types (P = 0.92) between 2011 and 2019. In the meantime, rates of smartphone ownership in millennials rose from 35% to 98%. Compared to 2019 volumes, the Egyptian mummy displayed an EOP enlargement corresponding to the 85th percentile for young women, and the XVIth century skull to the 73rd percentile for young men. In conclusion, on a population scale, prevalence and volume of enlarged EOP in millennials remain stable between 2011 and 2019, which makes the impact of rapidly growing modern environmental factors on EOP changes unlikely. EOP enlargement was also already present in ancient skulls from young individuals, with measurements within today's upper ranges.

Styloidogenic compression of the internal jugular vein, a new venous entrapment syndrome?

Internal jugular vein (IJV) thrombosis is mainly related to central venous catheter, malignancy, and ovarian hyperstimulation syndrome. We report a case of IJV thrombosis possibly related to IJV compression between the styloid process and the first cervical vertebra (C1) transverse process. To support this hypothesis, we perform radiological assessment of the IJV and examine its relationship with the styloid process and C1 transverse process in 34 controls. Our results showed a strong correlation between IJV diameter and styloid process-C1 transverse process distance. Compared to control subjects, our patient had a short styloid process-C1 transverse process distance, which suggests its involvement in IJV thrombosis.