[Ganglions of the wrist: proposals for topographical systematization and natural history]

We looked for the anatomic origin and mechanism of constitution of the so-called "ganglions" of the wrist.

Fifty-nine formations considered to be synovial ganglions were dissected and removed according to the same protocol by the same surgeon. Eleven were re-examined by a pathologist. All ganglions were extra-articular but had intra- and extra-capsular components. The extra-capsular part was the clinically palpable main cyst. The intra-capsular part was composed of the cystic stalk and its base of implantation. An intra-capsular stalk was present in 58 cases. The stalk was situated between the joint synovium and the capsula which it perforated at a weak point between two ligaments, forming a collar before expanding outwardly. Based on our findings, we propose a topographical systematization and natural history of ganglions of the wrist.

The stalk's implantation base was always located on bone and found in the intermediate area of Colomniati and Soubbotine, which lies outside the articular cartilage between the synovium and the ligamentous capsula. This area is exposed to mechanical stress initiating histological degenerative lesions, particularly mucoid degeneration. At the radiocarpal joint, the stalk's base of implantation was located at the distal end of the lateral dorsal or volar edge of the lunate bone or at the corresponding part of the scaphoid. The collar of the proximal ganglions was situated between the dorsal radiocarpal and transverse scaphotriquetral ligament. The collar of distal dorsal ganglions was situated between the transverse scaphotriquetral and the trapezotriquetral ligament. The collar of the lateral ganglions was situated between the lateral collateral and the transverse ligament. The collar of the volar ganglions was situated between the stylocarpal ligament and the radiolunotriquetral ligament, or between the different stylocarpal ligaments. At the level of the scaphotrapezal joint, the stalk's base of implantation was located near the collateral edge of the distal surface of the joint with the collar between the distal scaphoidal ligaments. The palmar cysts exhibited a collar between the stylocarpal ligaments and the radiolunotriquetral ligament or between the different stylocarpal ligaments.

At pathology examination, the lesions were not found to be different from those observed in other connective tissues exposed to overuse or repeated microtrauma (sports, occupational exposure). Anatomic conditions inside the joint capsula excluded extension of the mucoid degeneration transversally. The only issue was through the capsula, allowing the mucus enclosed in the connective tissue fibers to form the main cyst.

Knowledge of these different processes enabled a topographical systematization useful for complete surgical or arthroscopic removal of the ganglion. Complete resection would prevent recurrence.