Abstract
For as long as surgeons have been performing total and partial knee arthroplasty, surgeons have debated the efficacy, safety, and requirement of a pneumatic tourniquet. Advocates claim that blood loss is less, visualization is improved, and the cement technique is better with the use of a tourniquet. Others would argue that the use of the tourniquet or limited tourniquet use is safer, does not increase blood loss, and does not compromise visualization and cementing technique.
Multiple meta-analyses have been performed that provide very little true evidence of superiority. One such study from Yi et al, concludes that the use of the tourniquet reduces surgical time, intraoperative and total blood loss, but increases postoperative total blood loss. They also conclude that DVT and SSI are “relatively augmented” with use. There may be issues with the timing of tourniquet release in these pooled studies, with others stating that releasing the tourniquet prior to wound closure, supposedly for hemostasis, significantly increases the total and calculated blood loss. Huang et al report that with proper control in the amount of pressure, a debatable topic in and of itself, and shorter duration of inflation, release after closure can reduce blood loss without increased complications. One additional issue is patellar tracking, and the need to lateral release. The tourniquet significantly affects assessment of tracking and the need for lateral release, potentially causing the surgeon to unnecessarily perform a lateral release with the tourniquet inflated.
Lastly, research has suggested that using a tourniquet may affect recovery of lower extremity strength and function. Dennis et al compared quadriceps strength and found that use of the tourniquet resulted in “slightly” lower strength postoperatively out to 3 months. The fatal flaw in this study and others is that there is no accepted minimal clinically important difference for quad function, and thus they powered their study to detect a difference of 12 Nm, and the actual difference, while statistically significant, did not even meet their arbitrary power set point. Thus, while strength may be slightly impaired by the use of a tourniquet, it was not different enough to meet their criteria. Additionally, in their study, 64% of the “no-tourniquet” knees actually had a tourniquet used for cementation to “minimise blood at the bone-cement interface and maximise fixation”. Clearly, even these authors are concerned with the results of not using a tourniquet.
These authors utilise a pneumatic tourniquet in all cases of primary TKA and release the tourniquet prior to closure to ensure hemostasis and accurately assess patellar tracking. In doing so, we use the methodology of limb occlusion pressure to minimise the pressure to that necessary for ensuring a clear field. Additionally, these authors emphasise the ultimate in surgical efficiency allowing for extremely short tourniquet times, even in the most difficult cases. As an example, in 1300 consecutive obese patients with BMI equal or greater than 35, the average tourniquet time for primary TKA was 49 minutes. These short times, with the minimum pressure allow for the best of both worlds and little to no downside.
