Hamstring tendon graft for anterior cruciate ligament reconstruction - Home Study Program

AORN Journal,  Oct, 2002  by Deborah M. Boni,  George E. Herriott

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Placement of incisions. To achieve cleaner synovial penetration in the knee, the surgeon distends the patient's knee with saline before making the initial stab incision. The surgeon places his or her thumb in the angle between the patellar tendon and the joint line of the flexed knee and makes the incision above his or her thumb. The next stab incision is anteromedial. The point of entry should be slightly higher than that of the lateral incision to facilitate access to the region of the posterior horn of the meniscus.

Repair of associated injuries. Before the surgeon makes an incision to harvest the tendon graft, he or she assesses the knee arthroscopically for signs of meniscal tears and other associated injuries or to confirm the ACL rupture. If a meniscal tear is present, the surgeon either repairs it with 2-0 meniscal sutures or performs a partial meniscectomy using an aggressive arthroscopic blade and suction/shaver. After the surgeon assesses the knee and verifies an ACL rupture, he or she makes the incision to harvest the graft. Depending on surgeon preference, the tourniquet may be inflated to 300 mm Hg or 10 mm Hg higher than the patient's systolic pressure to provide a bloodless field. If the surgeon believes that the procedure may last longer than two hours, he or she may opt not to inflate the tourniquet.

Obtaining the tendon graft. An oblique or longitudinal incision approximately 4 cm to 7 cm long is made 2 cm to 3 cm medial to the tibial tubercle, and blunt dissection is carried through the subcutaneous fat to expose the sartorius muscle (Figure 4). The surgeon identifies by finger palpation the pes anserine tendons, which are the final common tendinous insertion of the sartorius, gracilis, and semitendinosus tendons along the proximal-medial aspect of the tibia (Figure 5). These muscles serve as flexors and internal rotators and help protect the knee from rotary as well as valgus stress. (6) The surgeon incises the skin and bluntly dissects through the subcutaneous fat to expose the sartorius. The gracilis and semitendinosus tendons can be seen and palpated as two small bumps lying under sartorial fascia. (7) After the surgeon separates the gracilis and semitendinosus tendons, he or she harvests them with a closed or slotted tendon stripper (Figure 6). The surgeon places a whip stitch on the tendon end with a #2 polyester braided nonabsorbable suture so that traction can be applied to each tendon. The surgeon pushes the tendon stripper in an upward direction along the course of the gracilis tendon until it is separated from its muscle belly. (8) The scrub person wraps the tendon graft in a moist laparotomy sponge and places it on the small back table. The surgeon harvests the semitendinosus tendon in the same manner. The tendons should measure approximately 100 mm to 150 mm in length when folded in half.

[FIGURE 4-6 OMITTED]

Preparing the graft. The assistant prepares the tendons using the graft preparation board. The graft preparation board is flat with a ruler along its edge to measure the length of the graft. A post at each end with removable clamps is used to hold the tendon securely. The assistant extracts muscle fibers from the tendon using a knife blade or periosteal elevator. After the tendon is free from muscle fibers, the assistant places a whip stitch on the proximal end of the tendon using a #2 polyester braided nonabsorbable suture. He or she folds the graft to half its original length and sizes the diameter using the tubular sizers ranging from 7 mm to 12 mm. The average graft size is between 8 mm and 9 mm in diameter (Figure 7). After sizing the graft, the assistant unfolds the graft to its original length and slips a button with a loop on the tendon. He or she again folds the graft in half and places it back on the graft master using the button holder attachment. The graft now is ready for later placement. The surgeon must create the tibial and femoral tunnels before the graft can be placed.