Gluteal muscle and subcutaneous tissue thicknesses in adults: a systematic review and meta-analysis

Background: Nurses often administer intramuscular injections at the gluteal site. This study aimed to determine gluteal muscle and subcutaneous tissue thicknesses in adults. Methods: Systematic review and meta-analysis. The databases Turkish Medline, Ulakbim, National Thesis Center, Cochrane, Web of Science, Science Direct, PubMed, CINAHL Plus with Full text (EBSCO host), OVID and SCOPUS were screened using the keywords ‘intramuscular injection’, ‘subcutaneous tissue thickness’, ‘muscle tissue thickness’ and ‘needle length’ between April and May 2021. The studies were evaluated with ultrasound. This study was reported according to the PRISMA recommendations. Results: Six studies met the eligibility criteria. The total sample size was 734 (women: 432, men: 302). The V method revealed that the ventrogluteal site had a muscle and subcutaneous tissue thickness of 38.071 ± 2.119 and 19.927 ± 2.493 mm, respectively. The geometric method revealed that the ventrogluteal site had a muscle and subcutaneous tissue thickness of 35.989 ± 4.190 and 19.661 ± 3.992 mm, respectively. The geometric method also revealed that the dorsogluteal site had a thickness of 42.560 ± 8.840 mm. According to the V method, females had thicker subcutaneous tissue at the ventrogluteal site than males ( Q = 5.37, df = 1, p = 0.0204). Body mass index did not affect the subcutaneous tissue thicknesses at the ventrogluteal site. Conclusion: The results show that gluteal muscle, subcutaneous and total tissue thicknesses vary across injection sites.