An Anatomical Study of Cricoarytenoid Joint Injection Technique in Cadaver Larynx

The conventional transoral microscopic approach for cricoarytenoid joint (CAJ) injections is well-established but requires general anesthesia and operating room facilities. Recent studies suggest that transcutaneous approaches might offer a more accessible alternative. This study compares the anatomical precision of two transcutaneous injection techniques: the cricothyroid membrane (CTM) and the thyrohyoid membrane (THM) approaches. To determine the most effective and precise method for transcutaneous access to the CAJ using CTM and THM approaches in cadaveric larynges. This anatomical study was conducted on 22 adult cadaver larynges (seven female, 15 male). Two injection approaches were tested: 1) the THM approach, with measurements of entry point distances, needle length, and angles, and 2) the CTM approach, similarly measured. The precision of needle placement was assessed by visual guidance and direct measurement. Statistical analysis was performed. THM Approach: The needle was inserted 1.92 ± 1.68 mm lateral to the midline and 11.6 ± 2.45 mm below the horizontal line, with a 25.1 ± 1.47 mm depth. The sagittal angle was 141° ± 1.82° (males) and 105° ± 12.4° (females), while the coronal angle was 17.2° ± 8.59° (males) and 16.5° ± 7.43° (females). Significant differences were found between genders in horizontal distance and sagittal angle (P < 0.05). CTM Approach: The needle was inserted 2.85 ± 1.1 mm lateral to the midline and advanced 28.34 ± 3.64 mm. The sagittal angle was 43.3° ± 11.1° (males) and 56.6° ± 12.9° (females), and the coronal angle was 138.9° ± 14.5° (males) and 147.1° ± 27.0° (females). This study enhances understanding of anatomical landmarks and technical considerations for CAJ injections. The THM and CTM approaches are effective and reliable, with potential implications for improving outpatient laryngeal interventions. Further research and clinical trials are necessary to validate these findings and optimize injection techniques.