Colin Malaska, MD
Resident Physician
University of Colorado, Department of Physical Medicine and Rehabilitation
Denver, Colorado, United States
Samuel Nortman, MD
Medical Director/Physiatry Section Chief, Physical Medicine and Rehabilitation Service
University of Colorado, Rocky Mountain Regional VA Medical Center
Aurora, Colorado, United States
A 59-year-old man with no significant medical history underwent an elective angiogram with geniculate artery embolization for recurrent hemarthroses following a total right knee arthroplasty. Immediately following the procedure, he exhibited absent ankle dorsiflexion strength and profound weakness with plantar flexion and eversion of his right ankle. He also experienced severe allodynia and hyperalgesia to the entire right lower leg. Inpatient workup included an MRI of the knee, infectious and autoinflammatory labs, and perfusion exams which were all unrevealing. He was discharged on multimodal pain therapy with an ankle-foot orthotic. At follow-up one month later, his allodynia and foot drop had not improved. He reported episodes of edema, hyperemia, and temperature changes in the right leg and ankle as well. Subsequent electromyography studies revealed distal polyneuropathies of both common peroneal and tibial nerves. These findings suggested a diagnosis of Type II Complex Regional Pain Syndrome (CRPS).
Discussions:
Geniculate artery embolization is regarded as a safe and well-tolerated procedure with indications for hemarthrosis as well as for its emerging use in severe osteoarthritic knee pain. Typical adverse events include transient skin discoloration and puncture site hematoma. However, symptoms of CRPS and foot drop have not been previously associated with this procedure. Coincidentally, there are similar case presentations following transradial and transfemoral cardiac catheterizations, suggesting a possible association between minor vascular trauma and the development of CRPS.
Conclusions:
CRPS is a debilitating and poorly understood condition that is typically associated with a traumatic or infectious trigger. However, this case demonstrates there could be a risk of developing CRPS with measurable neuropathies even from a minimally invasive vascular procedure. If genicular artery embolizations become more common for treating intractable osteoarthritic knee pain, it is especially important for physiatrists to further investigate its association with CRPS and nerve injury.
