The longitudinal incision should be 8 to 10 cm long and 1cm medial to the tendon. The surgeon should plan for the lower end to incorporate the tibial tunnel. The incision can be as short as 5 cm if cosmetic appearance is important. The author has used two separate transverse incisions in the past, but prefers, in a teaching situation, to use the longitudinal incision. Studies have shown that the two transverse incisions do not injure the infrapatellar branch of the nerve, and the patients are able to kneel after the patellar tendon harvest.
A double-bladed knife cuts a 10-mm wide graft from the central third of the tendon (Fig. 7.4). The surgeon should mark the length of the bone plugs, patella: 2.5 cm, tibia: 3.5 cm.
A Hall (Linvatec, Largo, FL) microoscillating saw is used to cut the bone plugs (Fig. 7.5). The initial cut is vertical through the cortex for 4 to 5 mm. Then the saw is angled at 60° and cut to 8 mm in depth. A deep V-cut should be avoided, as it can lead to a stress riser and late fracture. A 1/16-in. drill bit is used to make two holes in each bone plug. The bone plugs are gently lifted out with a small 1-cm wide osteotome. The base of the bone plug should be flat. The graft is freed from the fat pad with scissors.
If the bone plug is cut too thin, or fractured, then the fixation will have to be augmented by tying the sutures over a screw post or a button. The video on the CD demonstrates the technique of patellar tendon harvest.
The transfer of the graft from the harvest site to the back table is where it can be dropped (Fig. 7.6). Everyone on the team must be aware of that potential complication. The options for the dropped graft are to
change the graft to semitendinosus, allograft, or synthetic, or to cleanse the graft with chlorhexidine. The cleansing should consist of mechanically irrigating the graft by multiple separate rinsing.
On the back table, the author's group uses a graft preparation table. Measure the total length of the graft (Fig. 7.7). And use a small rongeur or bone cutter to size the bone plugs: the patella plug to 9 mm and the tibia bone plug to 10 mm. The cylindrical sizing tubes from Linvatec should be used to determine the size. The patella end should be made round to pass easily into the femoral tunnel. Leader sutures should be put through the holes in the bone plugs; in the patella use 2 number 0 Vicryl and in the tibia bone plug use 2 number 2 Ti-Cron. The Vicryl sutures (Ethicon, J&J, Boston, MA) are tied together in a knot that rests on the tip of the bone block. This makes it easy to pull into the femoral tunnel. A blue mark with a marking pen is placed at the patella bone tendon junction.
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