Johannes Barth1, Achilleas Boutsiadis2, Pablo Narbona3, Alexandre Lädermann4, Paolo Arrigoni5, Christopher R Adams6, Stephen S Burkhart7, Patrick J Denard8. 1. Department of Orthopaedic Surgery, Centre Osteoarticulaire des Cèdres, Grenoble, France. Electronic address: jrhbarth@yahoo.fr. 2. Department of Orthopaedic Surgery, Centre Osteoarticulaire des Cèdres, Grenoble, France. 3. Department of Shoulder Surgery, Sanatorio Allende, Córdoba, Argentina. 4. Division of Orthopaedics and Trauma Surgery, La Tour Hospital, Meyrin, Switzerland; Faculty of Medicine, University of Geneva, Geneva, Switzerland; Division of Orthopaedics and Trauma Surgery, Department of Surgery, Geneva University Hospitals, Geneva, Switzerland. 5. Università degli studi di Milano-Policlinico San Donato, Milano, Italy. 6. Department of Orthopaedics, NCH Hospital, Naples, FL, USA. 7. San Antonio Orthopaedic Group, San Antonio, TX, USA. 8. Southern Oregon Orthopedics, Medford, OR, USA.
Abstract
BACKGROUND: The aim of this study was to find reliable anatomic landmarks of the normal acromioclavicular joint (ACJ) that could enable the precise evaluation of the horizontal displacement of the clavicle after dislocation. The hypothesis was that the anterior borders of the acromion and the clavicle are always aligned in intact ACJs. MATERIALS AND METHODS: In 30 cadaveric specimens, the anterior and posterior borders of the ACJ's articular facets and the most prominent anterior and posterior bony landmarks of the acromion and the clavicle were identified. The anterior and posterior overhang of the acromion and the clavicle was measured in relation to the borders of the articular facets. Therefore, the possible anterior and posterior alignment of the ACJ was evaluated. RESULTS: Anteriorly, only 18 ACJs (60%) were aligned whereas 7 (24%) had major overhang of the acromion and 3 (10%) had major overhang of the clavicle. Similarly, 18 cases (60%) were posteriorly aligned, whereas 6 (20%) had major clavicular overhang and 4 (14%) had major overhang of the acromion. In 78% of these cases, the ACJ was aligned as well anteriorly as posteriorly (P < .001). Finally, the larger the width of the acromion (P = .032) or the clavicle (P = .049), the better the posterior joint alignment. CONCLUSION: Our hypothesis was not verified. The acromion and clavicle are not perfectly aligned in a significant number of specimens with intact ACJs (40% of cases). The most reliable landmarks remain their articular facets.
BACKGROUND: The aim of this study was to find reliable anatomic landmarks of the normal acromioclavicular joint (ACJ) that could enable the precise evaluation of the horizontal displacement of the clavicle after dislocation. The hypothesis was that the anterior borders of the acromion and the clavicle are always aligned in intact ACJs. MATERIALS AND METHODS: In 30 cadaveric specimens, the anterior and posterior borders of the ACJ's articular facets and the most prominent anterior and posterior bony landmarks of the acromion and the clavicle were identified. The anterior and posterior overhang of the acromion and the clavicle was measured in relation to the borders of the articular facets. Therefore, the possible anterior and posterior alignment of the ACJ was evaluated. RESULTS: Anteriorly, only 18 ACJs (60%) were aligned whereas 7 (24%) had major overhang of the acromion and 3 (10%) had major overhang of the clavicle. Similarly, 18 cases (60%) were posteriorly aligned, whereas 6 (20%) had major clavicular overhang and 4 (14%) had major overhang of the acromion. In 78% of these cases, the ACJ was aligned as well anteriorly as posteriorly (P < .001). Finally, the larger the width of the acromion (P = .032) or the clavicle (P = .049), the better the posterior joint alignment. CONCLUSION: Our hypothesis was not verified. The acromion and clavicle are not perfectly aligned in a significant number of specimens with intact ACJs (40% of cases). The most reliable landmarks remain their articular facets.
Authors: Jonas Pogorzelski; Knut Beitzel; Francesco Ranuccio; Klaus Wörtler; Andreas B Imhoff; Peter J Millett; Sepp Braun Journal: BMC Musculoskelet Disord Date: 2017-12-08 Impact factor: 2.362