Authors: Albert M Isaacs Rajiv Midha Nicholas M Desy Kimberly K Amrami Robert J Spinner
Publish Date: 2016/08/25
Volume: 158, Issue: 11, Pages: 2225-2229
Abstract
Intraneural ganglion cysts in the tarsal tunnel are rare We present a patient who had an intraneural ganglion cyst involving the medial and lateral plantar and distal tibial nerves Magnetic resonance imaging revealed evidence to support the jointrelated ie subtalar origin of the cyst Careful reinterpretation of the imaging supported a phasic mechanism ie crossover to explain the interrelated pathogenesis of the intraneural cyst within the three nerves This mechanism is analogous to that described for the prototypes—the peroneal tibial and sciatic nerves in the knee region—and can be generalized to other nerves in the foot and ankle region We believe that understanding the pathogenesis sheds light on the effective treatmentAnother scholarly contribution from the Spinner group confirming his articular branch theory for the formation of intraneural ganglion cysts In this case very convincing imaging and intraoperative evidence is presented to support the formation and spread of the cyst from the subtalar joint spreading proximally into the medial plantar nerve up to the tibial nerve and then extending distally into the lateral plantar nerve Presumably the tarsal tunnel prevents further proximal spread of the cyst The schematic figure is a beautiful rendering of what was found and seen The third figure shows similar findings in another outside case The authors are to be commended for making an important observation that impacts surgical treatment and clinical outcome by preventing intraneural recurrence of the ganglion cyst through an understanding of its pathogenesis
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