Roberto Cirocchi1, Isaac Cheruiyot2,3, Brandon Michael Henry4,5, Marco Artico6, Sara Gioia1, Piergaspare Palumbo7, Vincent Kipkorir4, Vito D'Andrea7, Justus Randolph8. 1. Department of Surgical Science, University of Perugia, Piazza dell'Universitá, 1, 06123, Perugia, PG, Italy. 2. Department of Human Anatomy, University of Nairobi, P.O. Box 30197, 00100, Nairobi, Kenya. isaacbmn@outlook.com. 3. International Evidence-Based Anatomy Working Group, 12 Kopernika St., 31-034, Krakow, Poland. isaacbmn@outlook.com. 4. Department of Human Anatomy, University of Nairobi, P.O. Box 30197, 00100, Nairobi, Kenya. 5. Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH, 45229, USA. 6. Department of Human Anatomy, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185, Rome, RM, Italy. 7. Department of General Surgery, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185, Rome, RM, Italy. 8. Georgia Baptist College of Nursing, Mercer University, 3001 Mercer University Drive, Atlanta, GA, 30341, USA.
Abstract
PURPOSE: To provide a comprehensive evidence-based assessment of the anatomical characteristics of the pyramidalis muscle (PM). MATERIALS AND METHODS: A thorough systematic search of the literature through August 31st 2020 was conducted on major electronic databases PubMed, Scopus and Web of Science (WOS) to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using MetaFor package in R and MetaXL. A random-effects model was applied. The primary outcome of interest was the prevalence of PM. The secondary outcomes were the dimensions (length and width) of the PM. RESULTS: A total of 11 studies (n = 787 patients; 1548 sides) were included in the meta-analysis. The multinomial pooled prevalence estimate (PPE) for a bilateral absence of the PM was 11.3% (95% CI [7.2%, 16.2%], 82.3% (95% CI [76.2%, 87.6%]) for a bilateral presence, and 6.3% (95% CI [3.3%, 10.2%]) for a unilateral presence. Of four studies (n = 37 patients) that reported the side of a unilateral presence, the PPE of a unilateral right-side presence was 42.2% (95% CI [23.0%, 62.3%]) compared to 57.8% for a unilateral left-side presence (95% CI [37.7%, 77.0%]). The mean length of the PM displayed high levels of heterogeneity, ranging from 3.12 to 12.50 cm. CONCLUSION: The pyramidalis muscle is a rather constant anatomical structure being present in approximately 90% of individuals.
PURPOSE: To provide a comprehensive evidence-based assessment of the anatomical characteristics of the pyramidalis muscle (PM). MATERIALS AND METHODS: A thorough systematic search of the literature through August 31st 2020 was conducted on major electronic databases PubMed, Scopus and Web of Science (WOS) to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using MetaFor package in R and MetaXL. A random-effects model was applied. The primary outcome of interest was the prevalence of PM. The secondary outcomes were the dimensions (length and width) of the PM. RESULTS: A total of 11 studies (n = 787 patients; 1548 sides) were included in the meta-analysis. The multinomial pooled prevalence estimate (PPE) for a bilateral absence of the PM was 11.3% (95% CI [7.2%, 16.2%], 82.3% (95% CI [76.2%, 87.6%]) for a bilateral presence, and 6.3% (95% CI [3.3%, 10.2%]) for a unilateral presence. Of four studies (n = 37 patients) that reported the side of a unilateral presence, the PPE of a unilateral right-side presence was 42.2% (95% CI [23.0%, 62.3%]) compared to 57.8% for a unilateral left-side presence (95% CI [37.7%, 77.0%]). The mean length of the PM displayed high levels of heterogeneity, ranging from 3.12 to 12.50 cm. CONCLUSION: The pyramidalis muscle is a rather constant anatomical structure being present in approximately 90% of individuals.