CORR Insights®: Ganglion Cysts of the Proximal Tibiofibular Joint: Low Risk of Recurrence After Total Cyst Excision.

Although rare, ganglion cysts arising from the proximal tibiofibular joint pose a surgical challenge when the peroneal nerve is involved, either extraneurally and/or intraneurally. The goals of treatment are neurologic recovery and prevention of recurrence. Because the condition is rare, there have only been case reports and a few studies with small groups of patients [3, 4, 6]; this dearth of evidence has led to a lack of clarity on many surgical issues. Should these cysts be treated with complete excision, or is decompression adequate? Complete excision would require intraneural dissection with the possibility of additional nerve damage, whereas decompression alone might lead to a higher risk of recurrence. Indeed, one study reported a very high risk of recurrence, particularly for recurrent cysts [6]. In the current study, Papanastassiou and colleagues [7] examined 30 complete cyst excisions and found a low risk of recurrence and improved functional outcomes after complete cyst excision and ligation of the communication with the joint, without fusion of the proximal tibiofibular joint or fibula excision. Because ganglion cysts are known to arise from the joint, ligation of this communication prevents recurrence, as shown in this study [7]. Despite these excellent results, questions remain regarding the surgical decisions for these patients; for example, in many patients, communication between the joint and ganglion around the nerve is difficult to identify on imaging and during surgery. For that reason, some authors have recommended fusion or excision of the proximal tibiofibular joint to prevent recurrence [1, 4, 6]. The etiology of these cysts could give us clues about how best to treat them; for example, some have suggested that intraneural extensions of these cysts could come from the joint itself, beginning in small articular branches of the nerve and working back to the parent nerve [1, 3, 9, 11]. If this is true, perhaps moreaggressive surgery than was used in the current study [7] could be justified. But we don’t know. Because of this, the clinician faces three main challenges. The first is delineating the exact extent of the cyst based on imaging and, if possible, the extent of communication with the proximal tibiofibular joint. MRI and Doppler ultrasound have been used separately and combined to reveal the extent of the cyst. Doppler is extremely observer-dependent and may not be able to identify smaller parts of the cyst [3]. MRI has become the imaging method of choice because it has higher resolution and because it allows three-plane visualization. MRI can also identify denervated muscles in the anterolateral compartment of the leg. MRI neurography also has been shown to accurately delineate even the intraneural extent of cysts [8] The second challenge for the clinician is knowing the exact surgical strategy to follow. There is no clarity on whether cysts should be treated with complete excision with intraneural microsurgical dissection or whether simple This CORR Insights is a commentary on the article “Ganglion Cysts of the Proximal Tibiofibular Joint: Low Risk of Recurrence After Total Cyst Excision” by Papanastassiou and colleagues available at: 10.1097/CORR. 0000000000001329. The author certifies that neither he, nor any members of his immediate family, has funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request. The opinions expressed are those of the writer, and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. M. Agarwal ✉, P. D. Hinduja Hospital and Medical Research Centre, Hinduja Clinic, Room 1417, Veer Savarkar Marg, Mahim, Mumbai 400016, India, Email: mgagarwal@gmail.com M. Agarwal, P. D. Hinduja Hospital and Medical Research Centre, Hinduja Clinic, Mumbai, India