John Defant, MD
Resident
The Ohio State University
Johnstown, Ohio, United States
Michael Baria, MD
Associate Professor of Physical Medicine and Rehabilitation; Director of Sports Orthobiologics
The Ohio State University
Columbus, Ohio, United States
Peroneal neuropathy from a ganglion cyst in the proximal tibiofibular syndesmosis
Case Description:
A 39-year-old female presented to our outpatient orthopedic clinic with complaints of difficulty running and driving due to right knee and leg pain for one week duration. She described it as a tingling, sharp pain located in the lateral aspect of the knee which radiated into her ankle on the lateral side. She denied prior injury. Denied numbness. The patient had preserved strength and sensation in the affected limb. She underwent right peroneal steroid injection and participated in physical therapy but had continued symptoms. MRI identified a 0.7 x 0.7 cm ganglion cyst in the proximal tibiofibular syndesmosis. The patient attempted joint aspiration however the cyst was unable to be aspirated secondary to proximity of peroneal nerve and nerve irritability symptoms. At the time of this submission, an EMG is pending.
Discussions:
Ganglion cysts in the tibiofibular syndesmosis causing peroneal compression and neuropathic pain is a rare event with limited description in the literature. Few reports of peroneal neuropathy due to cysts have been described and these cases vary in anatomical cyst location, treatment algorithm, and patient outcomes. This case provides insight into navigating an ambiguous area of treatment for a rare complication. Steroid injections and aspirations alone have been associated with the high rates of cyst reoccurrence, both of which provided little relief to our patient. MRI can demonstrate muscle denervation with hyperintensity on T2 signals but this is not specific for staging neuropathic progression. Electrodiagnostic studies are a helpful adjunctive assessment and can evaluate sensory and motor impairments to guide discussions of surgical planning.
Conclusions:
Peroneal neuropathy from a ganglion cyst in the proximal tibiofibular syndesmosis is a rare event. Treatment of this condition would benefit from further discussion of patient outcomes.
