Anatomical basis of arthroscopic capsulotomy for elbow stiffness

Stiffness is a frequent condition in elbow pathologies, both traumatic and non-traumatic, and usually requires an operative treatment including an anterior capsulotomy. Elbow arthroscopy is certainly an alternative to surgery, but the technique of arthroscopic capsulotomy remains controversial. Our aim was to study the anterior elbow capsule anatomy to recommend an efficient and safe arthroscopic capsulotomy. We dissected ten cadaveric elbows and analyzed the insertions of the anterior capsule, their variations and the relationships with the surrounding neurovascular structures (radial and median nerve, brachial artery). The influence of elbow flexion was studied on fresh elbows with radioscopic evaluation. The distances between the anterior capsule and the neurovascular structures were measured at four reference levels. The insertions of the anterior capsule were also studied on the embalmed elbows. The radial nerve is always the closest structure to the capsule, but in this study it was always protected by the brachialis muscle. The distance between the anterior capsule and the neurovascular structures is consistently higher on the proximal side, regardless of which structure is considered. The 90° flexion position allows the best capsular distension and offers optimal security with regard to neurovascular structures. All arthroscopic surgeons are concerned about potential neurovascular complications (varying from 0 to 14% in the literature). Previous anatomical studies examined the relationships between the arthroscopic portals and the neurovascular structures. This study developed a precise description of the relationship between the anterior capsule and the surrounding neurovascular structures, which let us recommend technical parameters to conduct a safe arthroscopic capsulotomy.