Keywords:
Prostheses, Image verification, Acute, Surgery, Imaging sequences, Complications, MR, Image manipulation / Reconstruction, Conventional radiography, Neuroradiology peripheral nerve, Musculoskeletal system, Anatomy
Authors:
C. Y. Ng1, J. S. Wong2, P. Suresh1, J. Keenan1; 1Plymouth/UK, 2Oswestry/UK
DOI:
10.26044/essr2019/P-0146
Background
Sciatic nerve injury is a recognised complication of dislocated prosthetic and native hips,
with the incidence varying from 0.7% to 10% 1,2.
However,
injury to the sciatic nerve after closed reduction of a dislocated hip replacement is rare3,4.
To our knowledge,
there are only 8 other documented cases of sciatic nerve injuries after closed reduction in the literature 1,3-9.
6 of which have described sciatic nerve entwinement around a total hip replacement (THR) 1,3,5-8.
Our case is the only other report so far that describes entwinement and traumatic splitting of the sciatic nerve by the femoral prosthesis demonstrated by cross-sectional imaging.
We present a case of a 77 year old woman who sustained a dislocated revised left THR 9 days after her procedure.
She underwent a difficult closed reduction under anaesthesia,
but unfortunately developed a dense left sciatic nerve palsy subsequently.
She then received a Metal-artefact reduction sequence (MARS) MRI,
which suggested sciatic nerve splitting and entwinement around the femoral neck prosthesis.
Urgent surgery was performed,
which confirmed the nerve was split and its anterior half entwined around the femoral neck prosthesis.
The patient was eventually discharged with residual left sided foot palsy.
Although it was not demonstrated in our case,
the initial hypothesis of a high bifurcation resulting in a split nerve entwinement was considered.
Hence,
this report will also highlight the incidences of the normal variants of the sciatic nerve and their detection using MRI.