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LAHAINA, Hawaii — While the overall incidence of nerve palsy
resulting from total hip replacement remains low, patients
undergoing revision surgery have a threefold risk for nerve
injury, and women are at a higher risk than men.
Thomas P. Schmalzried, MD, of St. Vincent Medical Center in Los
Angeles, said that in an analysis he conducted with colleagues
S. Noordin, MD, and Harlan C. Amstutz, MD, of more than 34,000
total hip replacements (primary and revision), there were 359
nerve palsies — a 1% overall prevalence. However, the incidence
among revision surgeries escalated to 2.5%, (0.9% for primary
cases), and patients with developmental dysplasia of the hip (DDH)
demonstrated a 5% risk for nerve palsy.
Even more alarming: nerve palsy occurred in women nearly twice
as much as men, he said.
"What this all says to me is that anatomy plays a role," he told
attendees at Orthopedics Today Hawaii 2008, here. "Nerve palsy
is a vexing complication. You might be doing what you usually
do, but because of the variances in anatomy — if the nerve isn't
where it usually is or if it takes a course around the hip joint
different from where it usually goes — indirect injury may be
the result."
He said the sciatic nerve is the most frequently injured nerve
in THR, accounting for 79% of all nerve palsies. Injury to the
sciatic nerve or the peroneal division of the sciatic nerve
typically occurs proximally at the level of the hip joint.
Electromyography has demonstrated evidence of nerve injury in
70% of extremities following THR, he added.
"In our research, femoral nerve injuries tend to be more
frequent when we use an anterolateral approach to THR," he said.
This is because the femoral nerve is close to the anterior
aspect of the hip joint and, consequently, to the anterior
acetabular retractors.
Schmalzried said that if neuropathy is suspected in a THR
patient, the orthopedic surgeon should consult with the
neurologist.
"Be nice to your neurologist," he said. "He can help you
validate your findings and identify the exact source or location
of the nerve injury."
For more information:
Schmalzried TP. Nerve and vascular injuries associated with
total hip arthroplasty. Presented at Orthopedics Today Hawaii
2008. Jan. 13-16, 2008. Lahaina, Maui, Hawaii.
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