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    Acromion-axillary nerve distance and its relation to the arm length in the prediction of the axillary nerve position: A clinical study
    (PubMed, 2022) Yıldırım, Cem; Demirel, Mehmet; Bayram, Erhan; Ekinci, Mehmet; Yılmaz, Murat
    Background: Because of the broad anatomic variation in the course of the axillary nerve, several cadaveric studies have investigated the acromion-axillary nerve distance and its association with the humeral length to predict the axillary nerve location. This study aimed to analyze the acromion-axillary nerve distance (AAND) and its relation to the arm length (AL) in patients who underwent internal plate fxation for proximal humerus fractures. Methods: The present prospective study involved 37 patients (15 female, 22 male; the mean age=51 years, age range 19–76) with displaced proximal humerus fractures treated by open reduction and internal fxation. After anatomic reduction and fxation were achieved, the following parameters were measured in each patient before wound closure without making an extra incision or dissection: (1) the distance from the anterolateral edge of the acromion to the course of the axillary nerve was recorded as the acromion-axillary nerve distance and (2) the distance from the anterolateral edge of the acromion to the lateral epicondyle of the humerus was recorded as arm length. The ratio of AAND to AL was then calculated and recorded as the axillary nerve index (ANI). Results: The mean AAND was 6±0.36 cm (range 5.5–6.6), and the mean arm length was 32.91±2.9 cm (range 24–38). The mean axillary nerve ratio was 0.18±0.02 (range 0.16 to 0.23). There was a signifcant moderate positive correlation between AL and AAND (p=0.006; r=0.447). The axillary nerve location was predictable in only 18% of the patients. Conclusion: During the anterolateral deltoid-splitting approach to the shoulder joint, 5.5 cm from the anterolateral edge of the acromion could be considered a safe zone to prevent possible axillary nerve injury. Keywords: Axillary nerve, Trans-deltoid approach, Deltoid-splitting approach, Iatrogenic nerve injury, Safe zone
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    The Effect of Supplementary Staple Fixation on Biomechanical Properties of Soft Tissue Graft Tibial Fixation in Anterior Cruciate Ligament Reconstruction
    (Georg Thieme Verlag Kg, 2024) Yildirim, Cem; Demirel, Mehmet; Koraman, Emre; Muratoglu, Osman Gorkem; Yamak, Fatih; Bozdag, Sureyya Ergun; Kocabey, Yavuz
    This study aimed to test and compare the biomechanical properties of three tibial fixation methods of anterior cruciate ligament (ACL) tendon grafts under cyclic load and load-to-failure testing in the bovine proximal tibiae, comprising (1) staple fixation alone, (2) interference screw fixation alone, and (3) interference screw fixation with a supplementary staple. Twenty-four bovine tibiae used in the study were divided into three groups (eight proximal tibiae in each group) based on tibial fixation methods of ACL tendon grafts: group A (a spiked ligament staple alone), group B (a cannulated interference screw alone), and group C (a cannulated interference screw with a supplementary staple). Each graft fixation was exposed to cyclic loading conditions. Significant differences were determined in failure load among the three groups (p = 0.008). The mean failure load was significantly higher in group B (717.04 +/- 218.51 N) than in group A (308.03 +/- 17.22 N) (p = 0.006). No significant differences were observed among the groups regarding axial stiffness (p = 0.442). Cyclic displacement differed significantly among the three groups (p = 0.005). In pairwise comparisons, the mean cyclic displacement was significantly higher in group A (8.22 +/- 3.24 mm) compared with group C (1.49 +/- 0.41 mm) (p = 0.005). Failure displacement varied considerably among the groups (p = 0.037). Although group B (15.53 +/- 6.43 mm) exhibited a greater mean failure displacement than both group A (4.9 +/- 0.75 mm) and group C (8.84 +/- 4.65 mm), these differences did not reach statistical significance (p = 0.602 and p = 0.329, respectively). Interference screw fixation alone and supplementary staple fixation have biomechanically similar characteristics in terms of initial strength and stiffness of tibial ACL soft tissue graft fixation. Regardless of staple use, an interference screw with the same diameter as the tibial tunnel can ensure sufficient tensile strength in tibial ACL graft fixation.