Clinical anatomy of the human Achilles subtendons twist - meta-analysis.

PURPOSE: This study aimed to provide a comprehensive and current overview of the anatomy of the Achilles tendon (AT) twisted structure, as there is a discrepancy in the literature regarding its rotating morphology. METHODS: An extensive literature search was conducted across multiple databases to identify all studies that reported relevant data on the AT torsion, with no date or language restrictions applied. Data was extracted and assessed for this meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included articles was examined using the anatomical quality assessment (AQUA) tool. RESULTS: Seven articles (n=690 limbs) were pooled into this meta-analysis. The prevalence of Achilles tendon torsion types was as follows: type II was the most common (46.7%, 95% CI: 31.6-60.9%), followed by type I (44.7%, 95% CI: 29.8-59.0%), and least commonly, type III (8.6%, 95% CI: 1.8-18.8%). Additionally, morphometric analysis, utilizing the method described by van Gils et al., revealed a mean Achilles tendon torsion of 46.5° (95% CI: 25.1-67.9°). CONCLUSIONS: This meta-analysis underscores the prominent and variable twist within the Achilles tendon among individuals, emphasizing the inherent diversity in AT morphology. Furthermore, the study highlights the importance of considering torsion angle as a potential factor influencing AT pathologies and biomechanical function.

Clinical anatomy of the popliteal artery and its implications in total knee arthroplasty: a systematic review and meta-analysis.

The popliteal artery (PA) is a lower extremity arterial vessel, a continuation of the superficial femoral artery. PA may be injured in the majority of total knee arthroplasty (TKA), as well as arthroscopic surgeries which may lead to acute ischemic injury. Our objective was analyzing morphometry of PA in relation to other structures both in flexion and extension of the knee, highlighting discrepancies in the PA's location in varying positions. Literature was reviewed in regards to morphological qualities, prevalence rates, and variants of PA were pooled. Five cadaveric and 14 radiological studies were included, totalling 1473 lower limbs. We found that PA, when nearing bone, was more predictable and fixed as seen in axial plane one and two centimeters distal to joint line at 0 degrees flexion. The distance between PA and posterior tibial cortex was estimated at 3.3 mm with 95% confidence interval (CI) 2.6-4.1 and 7.8 mm (95% CI 5.1-10.5) respectively. Once PA passed over and nearing the joint it had larger discrepancies with distance comparing the knee in 0 vs 90 degree flexion. Due to rise of TKA, arthroscopic surgeries and connected vascular complications PA has been investigated more frequently, and while majority of publications describes relationships between vessels of popliteal area and specific landmarks conducted with knee in extension, our study also implemented data regarding knee flexion thus encompassing the problem in a more dynamic manner. We believe this provides superior data for identification of PA, especially during knee surgery.

A meta-analysis of the accessory left atrial appendage and the left atrial diverticulum.

Left atrial (LA) structures, including the accessory left atrial appendage (aLAA) and left atrial diverticulum, have been studied based on their prevalence, shape, and association with arrhythmia and thrombi formation. A pooled prevalence with morphometric data has not been determined in previous research. Our goal is to provide structured, clinically relevant information on said structures for clinical practitioners to use in their daily work. We propose that morphometric data of additional LA structures is necessary when considering the possible complications during cardiac interventions. We conducted a meta-analysis of all relevant studies which used electrocardiogram (ECG)-gated computed tomography (CT) imaging to determine the prevalence of LA structures and record their morphometric characteristics as well as the presence of thrombi. Data were extracted from 19 studies (n = 6643 hearts). The pooled prevalence estimate of left atrial diverticulum and/or aLAAs were reported from 14 studies and was 28.8%. The most common location noted was anterosuperior in the LA with 70.2% of structures found there. Data regarding thrombi presence in left atrial diverticulums or aLAAs were extracted from 11 studies and a thrombus was present in 0.2%. The prevalence rates of aLAAs and left atrial diverticulums are essential in performing uncomplicated cardiac interventions and reducing risk of electrophysiological procedures. Our findings show a considerable prevalence of LA structures in varying populations, provides information regarding the general characteristics of said structures, and does not support the previously theorized associated risk of thrombus formation in relation to LA structure presence.

The meta-analysis and systematic review of prevalence and clinical anatomy of the arc of Buhler.

The arc of Buhler (AOB) is a direct anastomosis of the celiac axis and superior mesenteric artery. This paper reviews the literature on the AOB and provides accurate and up-to-date data on its prevalence, anatomy, and clinical significance. The main scholarly online databases were carefully searched for relevant studies related to the AOB. Information was gathered and formed the basis of the analysis of this study. In total, 11 studies were used in this meta-study, consisting of 3685 total patients tested and 50 cases of the AOB presented. The pooled prevalence estimate of the AOB was determined to be 1.7% (95% CI 0.9, 2.9). By imaging type, the prevalence of the AOB was 1.8% for radiological studies (n = 3485; 95% CI 0.9, 3.0), 1.4% for computed tomography (CT) studies (n = 1417; 95% CI 0.4, 3.0), and 1.9% for angiography studies (n = 2068; 95% CI 0.5, 4.0). The AOB is sufficiently significant and should be considered when planning surgeries or radiological procedures involving the abdomen.

Systematic review and meta-analysis of the prevalence of the retrotransverse foramen of the atlas.

The retrotransverse foramen (RTF) is a nonmetric variant of the atlas vertebra that can accommodate an anastomotic vertebral vein and occipital nerve. An understanding of this variation and its occurrence is crucial, as it could aid in explanation of the unidentified cause of the high prevalence of variability in this region. The aim of this meta-analysis was to obtain data on the prevalence of the RTF and its variations according to anatomy, sex, and ethnicity. A large-scale search was conducted through the major online databases to establish and determine the pool of studies reporting data relevant to the RTF. No date or language restrictions were applied. The data collection was categorized by prevalence, type (incomplete/complete), side, sex, ethnicity, laterality, and diameter. A total of 17 studies (n = 1979 subjects) were incorporated into our analysis. The overall pooled prevalence for a complete RTF was 11.4% and the overall pooled prevalence of an incomplete (partial) RTF was 9.6%. A complete RTF was most prevalent in Africa (Sub-Saharan population) (12.1%), followed by Europe (11.8%) and Asia (9.7%). As this variant occurs in a significant number of patients in all of the aforementioned populations, recognition, and awareness, especially with thorough investigation with computer tomography angiography (CTA) should be implemented, as it is the only possible way to visualize the possible contents of RTF.

Renal agenesis: A meta-analysis of its prevalence and clinical characteristics based on 15 641 184 patients.

Our objective was to analyse the newest relevant data on worldwide prevalence and associated symptoms of renal agenesis (RA). This meta-analysis builds on previous systematic reviews to include bilateral RA, its symptoms and data on gender, unilateral RA and anomaly location prevalence. Review of available data included records in English and other languages from PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect Korean Journal Database and Russian Citation Index and Google. A total of 15 641 184 patients were analysed in relation to the prevalence of RA. The pooled prevalence of RA was 0.03% (95% CI: 0.03%-0.04%). Based on 500 subjects, a pooled prevalence of 47.96% (95% CI: 31.55%-64.58%) for unilateral and 52.04% (95% CI: 35.42%-68.45%) for bilateral RA has been set. Our study presents the newest generalized findings on bilateral RA. There appears to be universal disease and symptom prevalence with minor differences between world regions, although quality of future observational research should include genomic data. This will provide even further insight into the prognosis of various renal anomalies and their etiologies.

Prevalence and morphometry of sternal and xiphoid foramen: a meta-analysis on 16,666 subjects.

PURPOSE: Sternal foramen is a perforation of the sternum that can be a source of misdiagnosis during radiographic imaging or life-threatening perforations during bone marrow sampling. The aim of this study was to conduct a meta-analysis on the prevalence, morphometrics, and location of foramen in the sternal body and xiphoid process, describe morphometric features of this phenomenon, and thus verify its clinical importance. Moreover, our secondary outcome was to compare effectiveness of various imaging methods in diagnosis of the sternal or xiphoid foramen. METHODS: A comprehensive search was conducted on major scientific databases to identify studies containing relevant information. Data on foramen's prevalence, location, morphometrics, and accompanying findings were extracted and pooled into a meta-analysis using MetaXL 5.0. RESULTS: Thirty-five studies (n = 16,666 subjects) were included. The overall pooled prevalence of a foramen in the sternal body and/or a xiphoid process was 8.9% (95% CI 6.5-11.7) and it equaled 6.5% (95% CI 5.6-7.6) for sternal body alone and 2.9% (95% CI 0.5-6.9) for the xiphoid process. The foramen was more prevalent in males than in females (12.2% vs. 6.8%). The prevalence of sternal foramen was higher in South American [13.9% (95% CI 11.2-16.9)] and African [13.6% (95% CI 9.7-18.0)] studies compared to North American [6.2% (95% CI 5.0-7.5)] and European populations [8.6% (95% CI 3.1-16.3)]. Mean transverse and vertical diameter of foramen equaled 4.7 mm (95% CI 3.8-5.5), and 5.6 mm (95% CI 4.2-6.9), respectively. CONCLUSION: Our analysis proves that the sternal foramina are structures of significant prevalence and size. Any physician should keep them in mind when performing punctures in this area.

The subscapularis muscle: A meta-analysis of its variations, prevalence, and anatomy.

BACKGROUND: The subscapularis (SSC) is the largest rotator cuff muscle and is involved in the medial rotation, abduction, adduction, and anterior stabilization of the shoulder. It is anatomically variable, as is the morphology and prevalence of the accessory SSC (aSSC), a rare muscle slip attached to the SSC. There is no current review investigating the prevalence and morphometrics of the SSC and aSSC. PURPOSE: To investigate the prevalence of the morphological variants of the SSC and aSSC via meta-analysis and review the relevant literature involving cadaveric, magnetic resonance imaging, and ultrasonographic studies. STUDY DESIGN: Meta-analysis. MATERIALS AND METHODS: Literature data reporting the prevalence rates and morphometrics of the SSC and aSSC and their variants were pooled. Literature searches and data analyses were performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Anatomical Quality Assurance guidelines. RESULTS: Forty-six studies, totaling 2166 shoulders, were assessed. The SSC showed an overall length, thickness, cross-sectional area, and volume of 152.2 mm (95% confidence interval, CI, 103.8-200.5 mm), 5.6 mm (95% CI, 4.6-6.6 mm), 18.1 cm2 (95% CI, 14.2-22.0 cm2 ), and 126.9 cm3 (95% CI, 87.2-166.5 cm3 ), respectively. The SSC displayed substantial variations in its origin and insertion points and in the composition of its tendon. The aSSC had an overall pooled prevalence of 24.6% (95% CI, 0.0%-76.9%). CONCLUSIONS: The SSC and aSSC have been implicated in multiple shoulder pathologies, including muscle and tendon ruptures and neurovascular compromise. A better understanding of SSC and aSSC variants when diagnosing and treating their related pathologies will reduce patient morbidity and improve treatment regimens.

Anatomy of the greater palatine foramen and canal and their clinical significance in relation to the greater palatine artery: a systematic review and meta-analysis.

PURPOSE: Accurate knowledge of greater palatine foramen (GPF) and greater palatine canal (GPC) anatomy is necessary to avoid injury to the greater palatine artery (GPA) when performing a variety of anesthesiologic, dental or surgical procedures. The aim of this paper was to perform a systematic review and meta-analysis of literature on the anatomy and localization of bony structures associated with the GPA, namely the GPF and GPC. METHODS: A systematic literature search was performed using PubMed, Embase, ScienceDirect, and Web of Science databases. Seventy-five studies were included in the meta-analysis (n = 22,202 subjects). RESULTS: The meta-analysis showed that the GPF is positioned 17.21 mm (95% CI = 16.34-18.09 mm) from the posterior nasal spine, 2.56 mm (95% CI = 1.90-3.22 mm) from the posterior border of the hard palate, 46.24 mm (95% CI = 44.30-48.18 mm) from the anterior nasal spine, 15.22 mm (95% CI = 15.00-15.43 mm) from the midline maxillary suture, 37.32 mm (95% CI = 36.19-38.45 mm) from the incisive foramen, and opposite the third maxillary molar (M3) in 64.9% (58.7-70.7%) of the total population. CONCLUSION: An up-to-date, comprehensive analysis of GPF and GPC clinical anatomy is presented. The results from this evidence-based anatomical study provides a unified set of data to aid clinicians in their practice.

Variations in human pulmonary vein ostia morphology: A systematic review with meta-analysis.

This study aimed to establish the most accurate and up-to-date anatomical knowledge of pulmonary veins (PV), ostia variations, diameters and ostial area, to provide physicians, especially heart and thoracic surgeons with exact knowledge concerning this area. The main online medical databases, such as PubMed, Embase, Scopus, Web of Science, and Google Scholar, were searched to gather all studies in which the variations, maximal diameter, and ostial area of the PVs were investigated. During the study, the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Additionally, the critical appraisal tool for anatomical meta-analysis (CATAM) was used to provide the highest quality findings. The most common ostia variation is the classical one, which contains the left superior pulmonary vein (LSPV), left inferior pulmonary vein (LIPV), right superior pulmonary vein (RSPV) and right inferior pulmonary vein (RIPV). The mean diameter and ostial area of each pulmonary vein were established in the general population and in multiple variations considering the method of collecting the data and geographical location. Significant variability in PV ostia is observed. Left-sided PVs have smaller ostia than the corresponding right-sided PVs, and the inferior PVs ostia are smaller than the superior. The LCPV ostium size is the largest among all veins analyzed, while the RMPV ostium is the smallest. The results of this meta-analysis are hoped to help clinicians in planning and performing procedures that involve the pulmonary and cardiac areas, especially catheter ablation for atrial fibrillation.

The persistent median artery and its vascular patterns: A meta-analysis of 10,394 subjects.

The presence of a persistent median artery (PMA) has been implicated in the development of compression neuropathies and surgical complications. Due to the large variability in the prevalence of the PMA and its subtypes in the literature, more awareness of its anatomy is needed. The aim of our meta-analysis was to find the pooled prevalence of the antebrachial and palmar persistent median arteries. An extensive search through the major databases was performed to identify all articles and references matching our inclusion criteria. The extracted data included methods of investigation, prevalence of the PMA, anatomical subtype (antebrachial, palmar), side, sex, laterality, and ethnicity. A total of 64 studies (n = 10,394 hands) were included in this meta-analysis. An antebrachial pattern was revealed to be more prevalent than a palmar pattern (34.0% vs. 8.6%). A palmar PMA was reported in 2.6% of patients undergoing surgery for carpal tunnel syndrome when compared to cadaveric studies of adult patients in which the prevalence was 8.6%. Both patterns of PMA are prevalent in a considerable portion of the general population. As the estimated prevalence of the PMA was found to be significantly lower in patients undergoing surgery for carpal tunnel syndrome than those reported in cadaveric studies, its etiological contribution to carpal tunnel syndrome is questionable. Surgeons operating on the forearm and carpal tunnel should understand the anatomy and surgical implications of the PMA and its anatomical patterns.

Neglected workforce: pharmacists and their health-related quality of life.

BACKGROUND: pharmacists remain on the frontline of public health around the globe and their performance directly impacts patients' safety. So far, to our knowledge, no European study has been dedicated to their heath-related quality of life (HQoL). Therefore, the primarily aim of our study was to evaluate HQoL of Polish pharmacists utilizing the SF-36 health survey with regard to anthropometric and lifestyle-related variables. METHODS: A total sample screened consisted of 1412 respondents, yet 765 pharmacists (mean age 40, 86.3% females) finally participated in the study. HQoL was assessed with the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). RESULTS: The lowest median scores were noted for general health (GH, 50.0) and vitality (V, 60.0) domains. No gender differences regarding physical and mental summary scores were found. Significant difference of HQoL was found among the assessed age groups in several domains, especially physical functioning (PF) and GH (p <0.001) scores, and especially in the group of 51-60-year-old-respondents. Correlations were found between PF (r = -0.29, p <0.001), GH (r = -0.25, p <0.001) and age as well PF (r = -0.27, p <0.001), GH (r = -0.21, p <0.001) and BMI. Self-assessed dietary habits were correlated with PF (r = 0.22, p <0.001), mental health (r = 0.25, p <0.001), GH (r = 0.27, p <0.001) and V (r = 0.30, p <0.001) scores. CONCLUSIONS: The analysis indicates that pharmacists tend to have similar mental and physical burden according to SF-36, with age, BMI and dietary habits as predominant factors influencing their HQoL. The study presents unique values for future comparative analyses related, for instance, to the influence of the ongoing pandemic on HQoL of health-care providers.

Innervation of the wrist joint: Literature review and clinical implications.

The aim of this study was to review the literature on the innervation of the wrist with an emphasis on pathological and therapeutic aspects. The nerves involved in wrist innervation and their mechanoreceptor endings are described. The literature over the past 30 years includes several topics that are still subjects of discussion and debate and require further research.

Clinical Anatomy of the Posterior Meniscofemoral Ligament of Wrisberg: An Original MRI Study, Meta-analysis, and Systematic Review.

BACKGROUND: The posterior meniscofemoral ligament (pMFL) of Wrisberg attaches to the posterior horn of the lateral meniscus and the lateral intercondylar aspect of the medial femoral condyle and passes posteriorly to the posterior cruciate ligament (PCL). The pMFL plays a role in recovery after PCL injuries and offers stability to the lateral meniscus, promoting normal knee function. PURPOSE/HYPOTHESIS: The aim of the magnetic resonance imaging (MRI) arm of this study was to evaluate the prevalence of the pMFL in Polish patients. The purpose of the systematic review and meta-analysis was to evaluate the clinical relevance of the pMFL in knee surgery. It was hypothesized that extensive variability exists in reports on the prevalence, function, and clinical significance of the pMFL. STUDY DESIGN: Cross-sectional study and systematic review; Level of evidence, 3. METHODS: A retrospective MRI investigation was conducted on 100 randomly selected lower limbs of Polish patients (56 male, 44 female) performed in 2019 to determine the prevalence of the pMFL. Additionally, an extensive literature search of major online databases was performed to evaluate all reported data on the pMFL. Assessments of article eligibility and data extraction were completed independently by 2 reviewers, and all disagreements were resolved via a consensus. A quality assessment of the included articles was performed using the Anatomical Quality Assessment tool. RESULTS: In the MRI arm of this study, the pMFL was observed in 73 of the 100 limbs. In the meta-analysis, 47 studies were included, totaling 4940 lower limbs. The pooled prevalence of the pMFL was found to be 70.4% (95% CI, 63.4%-76.9%); the mean length was 27.7 mm (95% CI, 24.8-30.5 mm) and the mean widths were 4.5, 6.1, and 4.1 mm for the meniscal and femoral attachments and midportion, respectively. The mean pMFL thickness was 2.3 mm (95% CI, 1.8-2.7 mm). CONCLUSION: Despite the variability in the literature, the pMFL was found to be a prevalent and large anatomic structure in the knee joint. The shared features of this ligament with the PCL necessitate the consideration of its value in planning and performing arthroscopic procedures of the knee.

Clinical Anatomy of the Anterior Meniscofemoral Ligament of Humphrey: An Original MRI Study, Meta-analysis, and Systematic Review.

BACKGROUND: The anterior meniscofemoral ligament (aMFL) of Humphrey is an anatomically variable fibrous band of connective tissue that attaches between the lateral aspect of the medial femoral condyle and posterior horn of the lateral meniscus, running posterior to the anterior cruciate ligament and anterior to the posterior cruciate ligament (PCL). The presence of an intact aMFL may contribute to stabilization of the lateral compartment of the knee joint. PURPOSE: The original magnetic resonance imaging (MRI) arm of this study aimed to assess the aMFL incidence among Polish patients. The goal of the systematic review and meta-analysis was to review the literature discussing the clinical anatomy of the aMFL and provide data on its prevalence. It was hypothesized that significant heterogeneity exists within the published literature. STUDY DESIGN: Cross-sectional study and systematic review; Level of evidence, 3. METHODS: A retrospective investigation was performed on the MRI scans of 100 knees (52 right, 48 left) of Polish patients. Scans were randomly selected from a database of MRI examinations performed in 2019. For the meta-analysis, major online databases were queried for data on the aMFL, and 2 authors independently assessed and extracted data from all included studies. A quality assessment of the included articles was performed using the Anatomical Quality Assessment tool. RESULTS: In the MRI arm of this study, the aMFL was found in 62 of the 100 lower limbs. The meta-analysis included 41 studies with a total of 4220 limbs. The aMFL was present in 55.5% (95% CI, 45.5%-65.3%) of cases. Arthroscopic studies yielded the highest prevalence (82.3% [95% CI, 36.6%-100.0%]); of MRI studies, the highest prevalence was at 3.0-T strength (51.0% [95% CI, 13.3%-88.2%]). CONCLUSION: Significant variability in the prevalence of the aMFL was found in the literature. More emphasis should be placed on the clinical relevance of injuries to the aMFL because of its significant role in the function of the knee. It is important to be aware that, because of the anatomy of the aMFL, the ligament can also function to support a torn PCL.

Evidence-Based Clinical Anatomy of the Popliteofibular Ligament and Its Importance in Orthopaedic Surgery: Cadaveric Versus Magnetic Resonance Imaging Meta-analysis and Radiological Study.

BACKGROUND: The popliteofibular ligament (PFL) is a static stabilizer of the posterolateral corner of the knee, preventing varus angulation, tibial rotation, and posterior translation. The PFL is anatomically variable, and there is no current review that outlines its prevalence rate and morphological variations. PURPOSE: To investigate the anatomic prevalence and morphological qualities of the PFL in various global patient populations via a meta-analysis of relevant literature involving both cadaveric dissections and patient-based research using magnetic resonance imaging (MRI) scans. STUDY DESIGN: Meta-analysis. METHODS: We pooled literature data detailing PFL prevalence rates and performed a retrospective MRI study of 100 knees to determine the overall PFL prevalence. Data searches and analyses were performed according to Anatomical Quality Assurance and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: There were 30 cadaveric studies and 11 MRI studies (including our radiological investigation), representing a total of 1595 lower limbs. The meta-analysis of cadaveric studies showed a higher prevalence of the PFL than the meta-analysis of MRI studies, with 98.4% (95% CI, 97.5%-99.2%) and 89.0% (95% CI, 73.9%-98.6%), respectively. Our MRI investigation reported a PFL prevalence of 92.0%. CONCLUSION: The PFL was found to be a constant or rarely absent anatomic structure of the human knee according to the analysis of cadaveric dissection studies, and it was identified notably less on MRI, albeit not significantly. Increasing PFL anatomic knowledge, including awareness of its prevalence and morphological diversity, will improve injury diagnoses, treatment methods, and prognoses.

The superficial temporal artery: A meta-analysis of its prevalence and morphology.

INTRODUCTION: The superficial temporal artery (STA) is a terminal branch of the external carotid artery. It supplies the regions of scalp and face. The morphometrical data concerning STAs are not consistent; therefore, in this systemic review and meta-analysis, we aimed in this to provide an up-to-date data on its anatomic features. MATERIAL AND METHODS: In order to do this, PubMed, Embase, ScienceDirect, and Web of Science were searched. We followed the Preferred Reporting Items and Review and Meta-Analyses guidelines for the meta-analysis. Studies that reported the prevalence and anatomical data regarding STA were included in further analyses. RESULTS: Out of 1,446 studies initially evaluated, 21 were included in the meta-analysis (874 patients/donors). The STA diameter was 1.5 mm (95% confidence interval [CI]: 1.47-1.53 mm). The frontal and parietal branches of the STA were present in 97.6% (95% CIs: 94.6-99.5%) and 96.4% (95% CIs: 93.5-98.5%) of the cases, respectively. The STA bifurcation point was located above the zygomatic arch in 79.1% (95% CI: 68.0-84.3), below the zygomatic arch in 6.7% (95% CI: 2.4-12.1), and on the zygomatic arch in 11.1% of the cases (95% CI: 5.4-17.5). There was no bifurcation of the STA in 3.1% of the cases (95% CI: 0.4-7.3). CONCLUSION: The most comprehensive analysis of STA morphological features is presented. The results from this evidence-based anatomical study will improve understanding of the clinical STA anatomy, which in turn has major implications for understanding the STA in clinical practice.

Prevalence and Clinical Implications of the Primitive Trigeminal Artery and its Variants: A Meta-Analysis.

BACKGROUND: The primitive trigeminal artery (PTA) is the most common and the largest persistent carotid-basilar anastomosis. Primitive trigeminal artery variants (PTAVs) are anastomoses between the internal carotid artery and cerebellar arteries. These vessels pose a risk of hemorrhagic or ischemic complications during neurosurgical procedures in the parasellar and intrasellar regions. The aim of this study was to determine the prevalence of both PTA and PTAVs and their clinically important anatomic features. METHODS: Major electronic databases were thoroughly searched for studies on PTA and PTAV. References in the included articles were also evaluated. Data regarding prevalence, laterality, origin, course patterns, and associated anomalies were extracted and pooled into a meta-analysis. RESULTS: A total of 39 studies (110,866 patients) were included in the meta-analysis. The total pooled prevalence estimate of PTA and PTAVs combined was 0.4% (95% confidence interval [CI], 0.3-0.5). Individually, PTA was present in 0.3% of patients and PTAV in 0.2%. Both arteries most often originated from the C4 internal carotid artery and took a course lateral to the dorsum sellae. The anterior inferior cerebellar artery type was the predominant PTAV (72.1%). Basilar artery hypoplasia was found in 42.5% of patients with a PTA. CONCLUSIONS: PTA and PTAVs are rare vessels, but they are clinically important because they can contribute to trigeminal neuralgia. Knowledge of the potential course of these arteries is essential in neuroradiology and neurosurgery, especially in minimally invasive procedures such as the endoscopic endonasal transsphenoidal approach to the pituitary gland and the percutaneous gasserian ganglion procedure.

The gastrocnemiofibular ligament: A new, more anatomically accurate name for the fabellofibular ligament-An original magnetic resonance imaging study and meta-analysis.

INTRODUCTION: The fabellofibular ligament (FFL) is a component of the posterolateral corner (PLC) of the knee and is an anatomically variable static stabilizer. Several investigations have reported prevalence rates for the FFL among their subjects, but no overall prevalence rate has been reported. MATERIALS AND METHODS: We conducted a meta-analysis of all relevant studies reporting prevalence rates of the FFL according to PRISMA and AQUA guidelines and pooled prevalence data using MetaXL 5.3. We also conducted a retroactive magnetic resonance imaging (MRI) study of 100 knees to assess FFL and fabella prevalence. RESULTS: Twenty-one studies (from 18 articles) and our MRI data were used in this meta-analysis (n = 1,176 knees). The pooled prevalence estimate (PPE) for FFL absence was 37.4% (95% confidence interval [CI], 24.5-51.3%). When divided by continent, PPEs of FFL absence were 31.5% (95% CI, 1.4-72.7%), 58.2% (95% CI, 44.1-71.6%), and 29.0% (95% CI, 14.7-45.7%) for North American, European, and Asian subjects, respectively. Cadaveric and MRI studies showed PPEs of FFL absence of 31.5% and 49.7%, respectively. Our MRI results showed PPEs of FFL and fabella absences of 42.0 and 80.0%, respectively. CONCLUSIONS: Understanding prevalence rates and anatomical geometry of the FFL will assist surgeons in repairing PLC injuries. Our MRI data and previous studies suggest the FFL is frequently present in knees lacking a fabella. Based on the observations of this study, we propose the ligament be renamed the gastrocnemiofibular ligament.

The Accessory Parotid Gland and its Clinical Significance.

PURPOSE: The accessory parotid gland is a collection of salivary tissue separate from the main parotid gland. When present, it may complicate parotidectomies, promote parotitis, and serve as a potential site for benign and malignant lesions to arise. The aim of this study was to provide a comprehensive and current overview of the anatomy of the accessory parotid gland, as there is a wide discrepancy in the literature regarding its prevalence. MATERIALS AND METHODS: The authors conducted a search in PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect, Korean Journal Database, and Russian Citation Index to identify all studies which reported relevant data on the accessory, with no date or language restrictions applied. Data on prevalence, side of occurrence, and sex dimorphism of the accessory parotid gland were extracted and pooled into a meta-analysis. RESULTS: A total of 13 articles (n = 3115 subjects) were included in the study. The results revealed that the overall pooled prevalence of an accessory parotid gland was 32.1% (95% confidence interval: 21.2-44.0). It was more prevalent in cadaveric studies (35.8%) than in computed tomography studies (21.5%), had a higher prevalence in Asia (33.8%) as compared to North America (23.5%), and when present, it was most often found as an unilateral structure (77.8%). CONCLUSIONS: With respect to the findings presented, the accessory parotid gland may be considered an anatomical variation likely to encounter in the population. More anatomical studies on the structure and its prevalence are needed, in all regions of the world, to provide a representative global overview.