Question: In patients having cemented total
knee arthroplasty, how effective is the use of tourniquets in preventing
blood loss?
Design: Randomized (allocation concealed), unblinded,
controlled trial with 7-day follow-up.
Setting: A hospital in Kingston, Ontario, Canada.
Patients: 63 patients (mean age, 71 years; 59% women)
who had cemented primary total knee arthroplasty. 94% had
a diagnosis of osteoarthritis and 6% had a diagnosis of
rheumatoid arthritis. Exclusion criteria were bilateral total knee
arthroplasty performed simultaneously or less than 3 months apart, bleeding
diathesis, revision total knee arthroplasty, musculoskeletal infection of
the ipsilateral limb, and peripheral vascular disease. Follow-up
was complete.
Intervention: Patients were assigned to a tourniquet group
(n = 33) or a non-tourniquet group (n = 30)
during cemented total knee arthroplasty. In the tourniquet group, the
leg was elevated and exsanguinated before the tourniquet was inflated
to 125 to 150 mm Hg above the systolic blood pressure (maximum,
300 mm Hg). The tourniquet was deflated after the bone cement set,
and electrocautery was used to achieve hemostasis. In the non-tourniquet
group, electrocautery was used as necessary. All patients had suction
wound drains.
Main outcome measures: The primary outcome measure
was blood loss, which included intraoperative blood loss, blood
loss due to Hemovac drainage, total measured blood loss (the sum
of intraoperative and Hemovac-drainage blood loss), and calculated
blood loss (adjusted for patient sex, height, and weight). Secondary
outcome measures were operative time, complications, and length
of hospital stay.
Main results: Although intraoperative blood loss
was greater in the non-tourniquet group (P < 0.001),
the total measured blood loss did not differ between groups (P > 0.25)
(table). The calculated blood loss was greater in the tourniquet
group than in the non-tourniquet group (P = 0.02)
(table). The tourniquet group required more transfusions (30% vs. 20%; P > 0.5)
and had a longer mean operative time (83 vs. 81 min; P > 0.5),
more complications (11 vs. 5; P = 0.06),
and a longer mean hospital stay (8.5 vs. 6.9 days; P = 0.075),
but the differences did not reach statistical significance.
Conclusion: In patients having cemented total knee arthroplasty,
the use of a tourniquet during the procedure did not reduce total
blood loss.