Chapter 2121: Chapter 1784: The Art of Surgery (Part 2)
The sound of the drill begins to pierce the air.
Gao Yuan picks up the guide pin and presses it against the medial side wall of the lateral femoral condyle. The tip of the guide pin nestles precisely into the center of the native footprint—a depression he had located with a probe. He adjusts the angle twice: the first for preliminary positioning, the second for fine-tuning. Both adjustments are subtle, likely only one or two degrees, but it’s these slight differences that determine if the tunnel direction will be parallel to the intercondylar notch roof or slightly angled. Parallel is ideal because the path of the graft closely mimics that of the native ligaments, optimizing biomechanics.
The drill begins to spin as Gao Yuan squeezes the trigger, his left hand gripping the handle of the guide pin, his right hand on the drill, together forming a stable triangle. As the drill bit penetrates the cortical bone, he feels an exceedingly slight vibration change, shifting from a dull vibration of hard bone to a gentle one of cancellous bone. Without pausing, he continues to advance. The drill bit moves through the cancellous bone like a needle passing through a sponge. Gao Yuan can judge the position of the drill bit within the bone based on the vibration frequency feedback, whether too shallow, too deep, off-track, or just right; all this information is transmitted through his palms to his brain. His brain makes judgments within 0.1 seconds, then his fingers execute the adjustments. The entire process requires no visual confirmation, not even conscious thought; it is an operation that has been internalized, turning into instinct.
As the drill bit breaks through the opposite side cortical bone, Gao Yuan feels a slight drop in his wrist. That "void feeling" triggers an immediate release of the trigger, stopping the drill. He withdraws the drill bit and inserts a probe into the tunnel to confirm direction and depth. The inner opening of the tunnel is centered at the native footprint, the outer opening at the predetermined position on the lateral femoral cortex; the length is four centimeters, direction parallel to the intercondylar notch, error not exceeding one millimeter.
Gao Yuan sets down the drill, stepping back half a step.
Someone murmurs something in the observation room, but the voice is too soft to discern. Yet everyone sees the tunnel’s position, perfectly centered like a laser-drilled hole. But Gao Yuan didn’t use lasers, didn’t use navigation, nor any computer-assisted devices. He only relied on one hand, a probe, a guide pin, and the most ordinary of drills.
The watching doctors sit up, realizing today’s surgery is indeed masterful, employing a positioning method unlike any mainstream technique.
Next, Gao Yuan needs to locate the tibial tunnel for the posterior cruciate ligament, the most technically challenging step of the entire surgery. The tibial insertion of the posterior cruciate ligament lies at the rear of the tibial plateau, less than a centimeter from the popliteal artery. The popliteal artery is one of the major vascular structures in the lower limb; any damage results in unimaginable consequences: massive bleeding, ischemia in the lower limb, even possible amputation. Therefore, most surgeons performing posterior cruciate reconstructions will use a special guide pin with protective devices, adopt X-ray guidance, or even split the surgery into two stages, doing the posterior cruciate first and reconstructing the anterior cruciate after healing to minimize risks.
Just as with the anterior cruciate tunnel positioning, the method for the posterior cruciate tunnel is unprecedented and novel, keeping the observing doctors riveted to the screen.
"Good!" Robert exclaims.
The drill sounds again, this time Gao Yuan is drilling slower and more cautiously. The tibial tunnel needs to be deeper than the femoral tunnel, penetrating thicker bone, with the direction being diagonally anteroinferior, forming a forty-five-degree angle with the tibial plateau. Gao Yuan stops every centimeter to use the probe and check the tissue ahead in the tunnel, confirming it doesn’t touch any blood vessels.
The tunnel is open; Gao Yuan threads a traction wire through it, pulling it out from the rear, preparing for the graft’s introduction.
Now, both tunnels are set: the femoral tunnel for the anterior cruciate ligament and the tibial tunnel for the posterior cruciate ligament. The entrances, exits, angles, and depths of both tunnels are confirmed accurate.
Next is graft preparation, Gao Yuan picks up the suture board and begins to weave the graft. This is not a simple operation: he must sew the tendon’s end into a closed loop fitted onto a fixed device. Each detail—needle placement, stitch tension, weaving density—affects the graft’s ultimate strength and healing quality. Gao Yuan’s sewing speed is rapid, yet each stitch remains precise. He uses a new method taught by Yang Ping.
The experts in the observation room quietly watch Gao Yuan’s stitching; the seemingly simple operation is handled with an artistic flair, the sewn graft akin to an exquisite craft.
The graft is ready. Gao Yuan threads each graft into its respective tunnel, pulling it out from the other end with the traction wire. The anterior cruciate graft threads from the femoral tunnel and exits the tibial tunnel; the posterior cruciate graft threads in from the tibial tunnel and is pulled from the rear. The two grafts cross within the joint cavity, forming an "X" shape.
Gao Yuan and Robert simultaneously hold the traction wires of the graft; this is the surgery’s most critical step—tension adjustment.
Tension is the hardest factor to control in ligament reconstruction; textbooks offer arrays of numbers: how many Newtons the anterior cruciate’s initial tension should be, how many for the posterior, but these numbers derive from in vitro experiments, not guaranteed to fit in a living body. Everyone’s joint shape is different, ligament tension varies, activity demands are not the same—a professional athlete and an average office worker require differing ligament tensions. Professional athletes need higher tension to cope with high-intensity loads, yet excessive tension can affect joint mobility, causing postoperative stiffness and pain. Where is this balance point? No formula can tell you.
This is where medicine, especially surgical experience, becomes essential; at this moment, it’s not data, but the surgeon’s heart and hand that are most reliable.
Gao Yuan pulls on the traction wire, slowly applying tension. He closes his eyes, feeling the resistance transmitted from the graft. The resistance isn’t rigid, but elastic, like stretching a rubber band, it gets tighter but retains a tendency to snap back. Gao Yuan searches for that "threshold"—the point where the graft is taut but hasn’t yet started exerting excessive tension. This threshold isn’t fixed; it shifts with knee flexion and extension angles, varies with posterior cruciate tension changes, differs according to patient’s weight.
After a long while, Gao Yuan says, "Fix it."
The fixing screws are driven into the tunnel. The graft is securely locked within the bone tunnel. The two ligaments form a perfect "X" at the knee joint’s center, like a miniature cable-stayed bridge, every anchor point precisely positioned, each "cable" tension perfectly set.
Gao Yuan reinserts the arthroscope into the joint cavity, conducting the final inspection.
Starting from zero degrees, he gradually flexes the patient’s knee to thirty degrees, sixty degrees, ninety degrees, one hundred twenty degrees, observing the reconstructed ligaments’ form and tension at each angle. The anterior cruciate ligament exhibits the highest tension at thirty degrees of knee flexion, relatively slack at ninety degrees; the posterior cruciate ligament is the opposite, with peak tension at ninety degrees. The tension changes of the two ligaments create a complementary relationship, this is what Yang Ping calls a "functional complex." As the knee flexes and extends, the two ligaments alternately bear loads, collaborating and constraint each other, akin to a pair of adept dance partners.
Gao Yuan gently hooks the anterior cruciate ligament with a probe. The ligament’s tension is moderate, neither slack nor overly tight. He then hooks the posterior cruciate ligament, equally perfect. He traces the probe tip along the ligament path, checking surface smoothness, ensuring no impingement, no risk of collision with the intercondylar notch. All check results are negative.
He sets down the probe, steps back half a step.
The surgery concludes.
The doctors in the observation room intuitively stand up, offering their respect to Director Gao’s surgery; this isn’t a simple operation, it is the art of surgery.
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