Early perioperative magnetic resonance findings in patients with foot drop following total hip Arthroplasty: A descriptive case-series. Issue 161 (April 2023)

• Record Type: Journal Article
• Authors: Thejeel, Bashiar; Tan, Ek Tsoon; Colucci, Philip G.; Gonzalez Della Valle, Alejandro; Sneag, Darryl B.
• Is Part Of: European journal of radiology. Issue 161(2023)
• Publication Date: 2023-04
• Subjects: Total hip arthroplasty -- Sciatic nerve -- MRI -- Foot drop; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2023.110727
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: Sciatic nerve injury is a potential complication in posterior approach total hip arthroplasty. Perioperative imaging with MR neurography can diagnose patients presenting with foot drop with iatrogenic sciatic nerve injuries. A spectrum of sciatic nerve injuries can be diagnosed including traction injury, compression, and tethering. Early diagnosis of sciatic nerve injury can expedite treatment and improve outcomes. Abstract: Purpose: This study aims to characterize iatrogenic sciatic nerve injury patterns in the early, perioperative period following posterior-approach total hip arthroplasty (THA) with magnetic resonance imaging (MRI). Methods: This was an IRB-approved retrospective analysis of patients acquired from a longitudinal, single site radiology database of patients who underwent MRI for "foot drop" within 4 weeks following posterior-approach THA surgery, over a 20-year period. Results: MRI exams from 51 patients (mean age 62 years; 32 females) who met inclusion criteria were evaluated. Mean time to MRI was 2.4 days. Of 51 patients, 43 underwent primary THA, 6 revision THA and 2 explantation with antibiotic spacer placement. Ten exams revealed a normal appearance of the sciatic nerve. Nineteen showed compression of the sciatic nerve by edema or a fluid collection, without intrinsic nerve abnormality. Fifteen demonstrated perineural tethering or scar/granulation tissue encasement of the nerve, and in half of these cases the sciatic nerve was enlarged and/or hyperintense on fluid-sensitive sequences. Six patients had sciatic nerve compression secondary to quadratus femoris retraction. Six patients had complete resolution of the foot drop at a mean follow-up of 37.3 months following surgery, and in these cases the sciatic nerve appeared normal on the initial postoperative MRI. Remaining patients all had persistent weakness and paresthesias in the sciatic nerve distribution at a mean follow-up duration of 34.3 months. Conclusion: This retrospective case series demonstrates various sciatic nerve injury patterns in the early perioperative period on MRI and proposes a targeted MRI protocol to evaluate the sciatic nerve post THA surgery.