Pretest

Introduction

Minimizing postoperative blood loss is every surgeon's goal. The logistical problems of pre-donation, the cost of marrow stimulating medications, and the vagaries of using nonautologous blood have spurred new efforts in decreasing peri- and postoperative blood loss.

Popliteal Artery

Although it has been suggested that no large blood vessels bleed in the area where total knee replacement (TKR) is performed, two exist. The first is the popliteal artery. When the knee is extended, the popliteal artery is placed under tension against the posterior capsule. Resecting the tibia in extension can result in the artery being cut by the saw blade if it were to pass beyond the confines of the posterior tibial metaphyseal cortex. Although it was taught that when the knee was flexed, the popliteal artery was displaced posteriorly, this was proven not to be the case by Zaidi et al.¹ Using duplex ultrasonography in 10 normal patients, they found that in 50% of knees, the artery was closer to the tibia in 90° of knee flexion than in full extension.

Care should be taken when resecting the tibia, especially in large posterior osteophytes. Although the tibia can be resected with the knee partially flexed, it may be safer in many cases to fully flex the knee and displace the tibia forward for this step in the surgery. Furthermore, the tibia can be resected in sections, allowing further visualization of its posterior aspect.

Lateral Inferior Genicular Artery

A second major source of bleeding is the lateral inferior genicular artery. This artery is immediately adjacent to the location on the posterolateral plateau where a retractor often is placed to displace the patella laterally. The author routinely coagulates the posterolateral corner because the vessel itself may be difficult to visualize.

Decreasing Blood Loss

Cyclooxygenase-1 inhibitory drugs can cause platelet inhibition and capillary oozing after the tourniquet is released in TKR. These medications should be discontinued prior to surgery. Unfortunately, no consensus exists regarding the exact time for discontinuation. More powerful anti-platelet drugs such as clopidogrel bisulfate should be discontinued at least 1 week prior to surgery.

Does releasing a tourniquet and obtaining hemostasis decrease the amount of bleeding compared to leaving the tourniquet inflated until the end of the procedure? The data are conflicting. Burkart et al² demonstrated no statistical difference in a randomized study in which cemented implants were used. Widman and Isacson³ likewise demonstrated in a randomized study no statistical difference in the amount of blood loss. They found, however, a great incidence of problems with the latter technique, including increased postoperative pain and increased difficulty in regaining motion.

Lotke et al⁴ found the greatest blood loss when the tourniquet was deflated intraoperatively and reinflated prior to closure. Abdel-Salam and Eyres⁵ studied patients randomly assigned either to having TKR with or without a tourniquet. No significant difference was noted in blood loss or operating time. They found, however, that patients without a tourniquet fared better postoperatively with less pain and earlier knee flexion.

Barwell et al⁶ studied the difference between deflating the tourniquet at the end of the procedure as opposed to deflating it when the implants were in place, and prior to closure. They found that patients in whom the tourniquet was released early had sonnerstraight leg raising and fewer wound complications.

It has been stated that by leaving a drain in the knee and connecting it to suction, the vessels are "kept open" and blood loss is increased. No data substantiate this allegation. Likewise it has been alleged that if the knee is not drained, it will fill with blood and tamponade any open vessels. This also is only anecdotal and a large hemarthrosis can lead to decreased wound healing and decreased ability to regain motion.

Lotke et al⁴ have shown that the use of a continuous passive motion machine or other early motion protocol types may increase bleeding transiently; this effect should be balanced against the salutary effects of early motion in regaining motion and function.

The author routinely uses ice packs around the surgical dressing for the first 48-72 hours postoperatively. Cooling may be expedited through the use of various cooling pads, which deliver a continuous effect without the logistics of filling ice packs.

Blood loss can be decreased by collagen shrinkage of the surfaces. The author has been using a radiofrequent energy generator to shrink collagen vessels. The uncovered areas of the bone, the cut surfaces of the capsule and quadriceps, and the posterolateral and -medial corners of the knee are routinely collagen shrunk using a bipolar generator with saline as an intermediary conductor.

In an ongoing multicenter study using a collagen shrinkage device, the early data demonstrate decreased blood loss in the postoperative drains. In the author's experience, this procedure adds less than 2 minutes of operating time and has been efficacious.

It has been suggested that blood loss can be deceased by using a fibrin sealant. This technique (Autoseal; Harvest Technologies Corp, Plymouth, Mass) requires that a sample of the patient's blood be centrifuged to form a fibrinogen button that is applied over the cut ends of the bone. The procedure is effective, however, it is time consuming and, currently, expensive to use.

References

1. Zaidi SH, Cobb AG, Bentley G. Danger to the popliteal artery in high tibial osteotomy. J Bone Joint Surg Br. 1995; 77:384-386.
2. Burkart BC, Bourne RB, Rorabeck CH, Kirk PG, Nott L. The efficacy of tourniquet release in blood conservation after total knee arthroplasty. Clin Orthop. 1994; 299:147-152.
3. Widman J, Isacson J. Surgical hemostasis after tourniquet release does not reduce blood loss in total knee replacement. A prospective randomized study of 81 patients. Acta Orthop Scand. 1999; 70:268-270.
4. Lotke PA, Faralli VJ, Orenstein EM, Ecker ML. Blood loss after total knee replacement. Effects of tourniquet release and continuous passive motion. J Bone Joint Surg Am. 1991; 73:1037-1040.
5. Abdel-Salam A, Eyres KS. Effects of tourniquet during total knee arthroplasty. A prospective randomized study. J Bone Joint Surg Br. 1995; 77:250-253.
6. Barwell J, Anderson G, Hassan A, Rawlings I, Barwell NJ. The effects of early tourniquet release during total knee arthroplasty: A prospective randomized double-blind study. J Bone Joint Surg Br. 1997; 79:265-268.