Arthroscopic wrist ganglionectomy

Relevant anatomy and etiology

The dorsal wrist ganglion (DWG) is the most common cystic soft tissue tumor of the wrist. It typically originates from the dorsal portion of the scapholunate (SL) ligament at the junction of the dorsal capsular insertion, and it often expands dorsally between the third and fourth extensor compartments. It is filled with a viscous gel containing glucosamine, albumen, globulin, and hyaluronic acid. The cyst wall is made up of compressed collagen fibers and is sparsely lined with flattened cells with no true epithelial or synovial lining. A one-way valve mechanism has been proposed as an explanation for the expansion of the ganglion sac. Osterman and Raphael were only able to identify a definite ganglion stalk in 11 out of 18 patients who underwent an arthroscopic dorsal wrist ganglion excision. They postulated that because the dorsal capsular reflection separated the radiocarpal and midcarpal joints, it was possible for a ganglion stalk to travel toward the SL ligament within the substance of the dorsal capsular reflection, rather than through the radiocarpal or midcarpal spaces. As a result, the stalk may never be visualized arthroscopically. Rizzo et al. noted a discrete stalk in 12 out of 41 cases. In their series of arthroscopic ganglion resection, Edwards and Johansen found a discrete stalk in only 4 out of 45 cases, and noted diffuse cystic material and redundant capsular tissue in 38 out of 45 patients who underwent an arthroscopic DWG resection. This tissue was differentiated from synovitis in that it appeared devoid of vasculature and lacked the characteristic fronds of synovitis. Cystic material appeared to arise from the radiocarpal joint exclusively in 11 out of 42 cases and involved the midcarpal joint in 31 out of 42 cases. It extended from the radiocarpal joint into the midcarpal joint in 29 out of 42 cases and arose exclusively from the midcarpal joint in just 2 out of 42 cases. Lee et al. described injecting methylene blue into the ganglion to aid in identification of the stalk arthroscopically. Ahsan and Yao used this technique in 27 patients with a dorsal wrist ganglion and identified a ganglion stalk in 100% of the color-aided arthroscopic excisions. They reported 1 recurrence following excision.

Yamamoto et al. described the use of sonography during an arthroscopic ganglion resection in 22 patients to visualize the ganglion stalk and protect any adjacent neurovascular structures. There were 16 DWGs and 6 volar wrist ganglions. Sonographic visualization of the ganglion stalk, adjacent structures, and the tip of the arthroscopic shaver was possible in all 22 cases. This allowed them to verify a complete resection of the ganglion stalk, even though only 4 of the stalks were visible arthroscopically. Because the arthroscopic shaver was clearly visualized with an acoustic shadow during shaving, they were able to guide the shaver to the ganglion stalk and control both the depth and the direction of the shaver to ensure excision of the stalk and to aid in preventing extensor tendon injury. The sonography also allowed them to visualize the branches of the radial and ulnar arteries during resection of a volar wrist ganglion, which decreased the risk of vascular injury. At a mean follow-up of 21 months (range, 16–28 mo) 2 patients had recurrent DWGs, which is similar to other studies.

The etiology of the wrist ganglion is still debated. Ganglia arising from the wrist can be idiopathic; associated with an underlying joint disorder such as an interosseous ligament tear or laxity, or a triangular fibrocartilage complex (TFCC) tear; or associated with degenerative arthritis. Povlsen and Peckett noted abnormalities of the SL joint in 12 out of 16 and 2 out of 16 lunotriquetral (LT) joints in patients who underwent an arthroscopic DWG resection. Similarly, Langner et al. prospectively examined 46 patients who underwent an arthroscopic resection of a painful DWG (26 patients) or volar wrist ganglion (20 patients). There were 18 primary and 28 recurrent ganglions. They identified 22 TFCC lesions (48%) and 2 intracarpal ligament lesions. The TFCC perforations were more commonly associated with both the primary and recurrent volar ganglions. In Edwards et al.’s study, out of 45 cases the SL joint demonstrated Geissler type I laxity in 2 cases, type II in 22 cases, type III in 20 cases, and type IV in 1 case. The LT joint demonstrated Geissler type II laxity in 6 cases and type III in 39 cases.

Volar wrist ganglia occur less frequently than dorsal wrist ganglia. They arise either from the radioscaphoid joint, usually between the radioscaphocapitate (RSC) ligament and long radiolunate ligament (LRL), or from the midcarpal STT joint. They may occasionally originate from the flexor carpi radialis (FCR) tendon. They are histologically identical, but they are often intertwined with the radial artery.

Diagnosis

Patients with a dorsal wrist ganglion often present with complaints of a tender bump over the dorsum of their wrist. Although it may be related to minor trauma, the lesions often occur spontaneously. There may be either a history of slow growth with a fluctuation in size or a sudden onset. Forced wrist extension, such as the push-up position, often aggravates the pain. On the wrist examination, there is a round, minimally mobile subcutaneous lesion that may or may not be locally tender. The lesion will transilluminate, which differentiates it from a solid lesion. Synovitis from an underlying chronic SL dissociation may mimic the ganglion, but the thickened synovium is usually ill defined and is associated with more carpal tenderness and possibly a positive Watson test.

The volar wrist ganglion has a similar appearance. It often arises in the interval between the radial artery and FCR. On palpation there may be some mild tenderness but there should be no thrill or bruit. An Allen’s test should be performed to rule out an aneurysm or AV fistula. Transillumination may also be helpful. Other causes of volar wrist pain should be excluded including trapeziometacarpal or scaphotrapezial (ST) osteoarthritis (OA), flexor carpi radialis (FCR) tendinitis, and de Quervain disease. Plain radiographs should be taken to rule out any underlying carpal instability, or radioscaphoid or ST OA. A T2-weighted MRI will reveal an increased fluid signal and differentiate this from a solid lesion. Ultrasound can also be used for this purpose.

Treatment