| Abstract ID |
| 20260127 |
| Category |
| Shoulder: Miscellaneous |
| Preferable Presentation |
| Both |
| Title |
| NEUROVASCULAR SAFETY MARGINS AROUND THE CORACOID PROCESS IN INTACT AND SIMULATED ROCKWOOD TYPE V ACROMIOCLAVICULAR JOINT INJURIES |
| Author |
|
| Presenter |
| Chaiwat Chuaychoosakoon |
| Abstract |
| Background Coracoclavicular stabilization is a common surgical treatment for high-grade acromioclavicular (AC) joint injuries, but major neurovascular structures lie close to the coracoid process, creating a risk of iatrogenic injury during open and arthroscopic procedures. Most anatomical studies have quantified coracoid-to-neurovascular distances in intact shoulders, so it remains unclear whether these data can be safely extrapolated to Rockwood type V injuries, in which the clavicle and scapula are malaligned and the spatial relationship between the coracoid and neurovascular bundle is altered. Objectives To compare the distances from the anteromedial coracoid tip and base to the lateral border of the neurovascular bundle between intact AC joints and simulated Rockwood type V AC joint injuries across three surgical positions and three measurement planes, and to determine whether intact-shoulder data can be used to guide safer surgery in high-grade injuries. Study design Cadaveric anatomical study. Methods Fifteen fresh frozen full body cadavers were dissected to expose the coracoid process and the lateral border of the neurovascular bundle. Standardized points at the anteromedial coracoid tip and base were marked with Kirschner wires. Distances from each point to the lateral border of the neurovascular bundle were measured with a digital Vernier caliper in the horizontal, oblique, and vertical planes in supine, beach chair, and lateral decubitus positions. All measurements were obtained first with an intact AC joint and then repeated after creating a simulated Rockwood type V injury by transecting the acromioclavicular and coracoclavicular ligaments and detaching the deltotrapezial fascia. Paired t tests were used to compare intact and simulated conditions for each position and plane (P < 0.05). Results The mean donor age was 69.2 ± 6.5 years (8 male, 7 female). In simulated Rockwood type V injuries, distances from both the coracoid tip and base to the neurovascular bundle were significantly greater than those in intact AC joints in the supine and beach chair positions in most measurement planes (P < 0.05). In the lateral decubitus position, however, no significant differences were observed between simulated and intact conditions in several planes, including all planes at the coracoid tip and the oblique and vertical planes at the coracoid base (P ≥ 0.05). Across conditions, the supine position generally provided the greatest distances, the beach chair position yielded intermediate distances, and the lateral decubitus position produced the shortest distances. Conclusions Neurovascular distances from the coracoid tip and base are greater in simulated Rockwood type V AC joint injuries than in intact AC joints in the supine and beach chair positions, suggesting that anatomical data from intact shoulders underestimate true safety margins in high-grade injuries. Surgeons can use intact-shoulder distances as conservative guides for coracoclavicular stabilization in the supine and beach chair positions or directly apply the position- and plane-specific values from this study to further reduce the risk of neurovascular injury. Because safety margins are smallest and differences between intact and high-grade conditions are less pronounced in the lateral decubitus position, this position warrants particular caution during procedures around the coracoid process. |