gms | German Medical Science

Objectives/Interrogation: Several surgical approaches to the medial elbow have been described however it remains unclear which exposure provides the optimal view of relevant medial elbow structures. The purpose of this anatomic study is to determine the visible surface area of the coronoid process, distal humerus and radial head through five described approaches to the medial elbow; the muscle splitting approach to the ulnar collateral ligament of the elbow, the medial "Over the Top" approach, the extended medial elbow approach, the floor of the ulnar nerve approach, and the Taylor and Scham approach.

Methods: Eight fresh frozen cadaveric upper extremity specimens were dissected. Five surgical approaches were performed on each specimen, the muscle splitting approach to the ulnar collateral ligament of the elbow, the medial "Over the Top" approach, the extended medial elbow approach, the floor of the ulnar nerve approach, and the Taylor and Scham approach. The sequence was standardized, moving from least to most invasive. After completing each exposure, the intervals were closed prior to the next interval being exposed. The muscle splitting approach to the ulnar collateral ligament was performed first, followed by the medial "Over the Top" approach, the extended medial elbow approach, the floor of the ulnar nerve approach, and the Taylor and Scham Approach. After each surgical approach was performed, standard retractors were placed and imaging of bony visualization was performed using a laser surface scanning system (Artec Space Spider, Artec 3D, Santa Clara, California) and digitized. The radius, ulna and humerus were then stripped of all soft tissue and laser surface scanned in the same manner. The scans were then segmented using commercially available digital software (Geomagic Wrap, 3D Systems Corporation, Rock Hill, South Carolina) and the surface area visualized was determined.

Results and Conclusions: The extended medial elbow approach showed the highest proportion of the total elbow joint (coronoid, distal humerus and radial head) from the medial side, with a surface area of 13.9cm2, or 15% of the joint. It also provided the best visualization of the coronoid (3.2cm2 or 26% of the surface area), and distal humerus (9.9cm2 or 15%), while the medial "Over the Top" approach was best at visualizing the radial head (0.8cm2 or 7%). In conclusion, the extended medial elbow approach provides the greatest surface area visualization of the distal humerus and coronoid process from the medial side.