461 - Right Lumbosacral Plexopathy After Left Total Hip Arthroplasty

Case Diagnosis: Acute lumbosacral plexopathy after contralateral total hip arthroplasty.

Case Description: We present a 53-year-old male with history of left total hip arthroplasty, found to have hardware failure who underwent a revision. His post-operative course was complicated by right lower extremity pain, paresthesias, and footdrop. His exam was significant for trace activation of the ankle dorsiflexors, reduced ankle plantarflexor strength, diminished sensation of the lateral thigh, and allodynia of the plantar surface of the foot. He completed a two-week course of acute inpatient rehabilitation and was followed closely by PM&R after discharge. He underwent an electrodiagnostic evaluation notable for decreased amplitude of the tibial nerve, the peroneal nerve above and below the fibular head, absent right sural response, positive sharp waves and fibrillations in the tensor fascia lata, tibialis anterior, and gastrocnemius—consistent with a lumbosacral plexopathy.

Discussions: Although uncommon, nerve injuries are serious complications of procedures with prolonged static positioning such as total hip arthroplasties. Nerves comprising the lumbosacral plexus are vulnerable when patients are placed in the lateral position. Additionally, revision total hip arthroplasties have a higher incidence of nerve injury. Although the incidence of lumbosacral plexopathy after total hip arthroplasty is unclear, previous research suggests it is higher than expected, as most post-operative plexopathy cases were misdiagnosed as femoral or sciatic nerve injuries. Because the lumbosacral plexus innervates a bulk of lower extremity musculature, damage can have profound functional consequences.

Conclusions: Physiatrists are uniquely positioned to assist patients with complications such as plexopathies because they commonly care for patients in the post-operative period, have the required electrodiagnostic capabilities, and frequently manage both neuropathic pain and functional impairments. In this case, a multiphase approach to care proved to be effective with an initial stay in the acute rehabilitation setting followed by close outpatient monitoring, highlighting the importance of longitudinal physiatric care.