Background:
Controversy exists regarding the safety of bilateral simultaneous
total hip arthroplasty, in part because of the potentially higher
prevalence of pulmonary fat embolism. The purpose of the present
study was to determine if unilateral and bilateral simultaneous
total hip arthroplasty procedures resulted in different prevalences
of fat embolization, different degrees of hemodynamic compromise,
or different levels of hypoxemia or mental status changes.
Methods:
One hundred and fifty-six consecutive patients undergoing primary
total hip arthroplasty were prospectively enrolled in the study.
The study group included fifty patients undergoing bilateral simultaneous
total hip arthroplasty and 106 patients undergoing unilateral total
hip arthroplasty. One hundred hips were treated with a cemented
stem, and 106 were treated with a cementless stem. Arterial and
right atrial blood samples were obtained before implantation (baseline);
at one, three, five, and ten minutes after implantation of the acetabular
and femoral components; and at twenty-four and forty-eight hours after
the operation. Arterial blood pressure, right atrial pressure, arterial
oxygen tension, and carbon-dioxide tension were also monitored at
these times. The presence of lipid and cellular contents of bone
marrow was determined.
Results:
The prevalence of fat embolism was not significantly different
between the groups managed with bilateral and unilateral total hip
arthroplasty or between the groups managed with cemented and cementless
stems. Similarly, the prevalence of bone-marrow-cell embolization
was not significantly different between the groups managed with
bilateral and unilateral total hip arthroplasty or between the groups
managed with cemented and cementless stems. Patients with bone-marrow-cell
embolization had a significantly lower arterial oxygen tension (p
= 0.022) and oxygen saturation (p = 0.017) than did patients without
bone-marrow-cell embolization on the first postoperative day. Four
patients with bone-marrow cells in the blood samples that were obtained
from the right atrium on the first postoperative day had development
of diffuse encephalopathy with confusion and agitation that lasted
for about twenty-four hours.
Conclusions:
The prevalence of fat and bone-marrow-cell embolization was similar
in the groups managed with bilateral simultaneous and unilateral
total hip arthroplasty as well as in the groups managed with cemented
and cementless stems.