The tormenting three o'clock in the afternoon finally arrived.

Director Han didn't come back, Director Ouyang and Director Bai went out to fly knives, and Director Ding was a dragon anyway.

Director Tian and Dr. Jin are here. Originally, this kind of learning class was mainly for young doctors.

The video of Professor Zhang's surgery was repeatedly played on the high-definition screen.

There were a lot of people, so Yao Ling hurriedly arranged for two nurses to help and add some folding chairs inside.

Zhang Lin sat at the outermost desk in the first row, spread out a notebook, and everyone signed and clocked in on the notebook in turn.

"Sign in, brothers, don't forget."

Zhang Lin shouted loudly, and if he had forgotten, hurry up and make up for it.

Professor Zhang didn't come for the time being, and he asked Yang Ping to inform him when he was about to finish, and he wanted to say a few words.

He said that with him, the children were afraid to speak, so he didn't make a mess.

"Professor Zhang, you're in good spirits today." Someone greeted Zhang Lin.

Everyone was shocked, Nima, did Professor Zhang call him casually?

"Hurry up, there's no seat."

"In the elevator."

The WeChat group is urging each other.

The people were almost there, Zhang Lin Xiaowu maintained the order, Director Tian looked at the watch, and explained to Song Zimo: "Start on time at three o'clock." ”

At the meeting, Director Tian had the highest title, so he naturally presided over the meeting, and he also wanted to listen to this lesson, for Professor Zhang's operation, he was so fast and bold, he also wanted to participate in the discussion.

The seats were full, and there were a lot of folding chairs around, but it was still not enough, and some people were standing.

Usually small lectures, some guys have various reasons, and there are always people who will find ways to slip away.

Today, except for the emergency surgery with the general inpatient, all the others came, all the interns arrived, and people from other departments also came. It's not too crowded.

Three o'clock, start on time.

Song Zimo stepped onto the podium, with the iconic unbuttoned white coat.

He is a natural star, in addition to his excellent appearance, confident temperament, and his pair of Thor's eyes, which are full of electricity, and have made countless girls fall for him.

But today, the vast majority of those present are men, as if no matter how much electricity there is, it is empty.

"Biomechanical Analysis of Hip Fractures"

Biomechanics, no stranger to orthopedic surgeons, a compulsory course for graduate students.

When you see these words, you are familiar and unfamiliar, and for biomechanics, there are only these words left in your mind, and you can't even remember the fragmentary concepts.

"For Professor Zhang Zongshun's operation, why did he walk on the ground so quickly, and he was completely weight-bearing, everyone is very concerned about this issue. Today, Dr. Yang and I will use the lecture time to study and discuss with you. Song Zimo spoke at a medium speed and spoke clearly.

"Intertrochanteric fractures of the femur are no strangers to frequent contact with surgery. What everyone wonders about is that this intertrochanteric fracture is shattered, and it can actually walk on the ground within 24 hours? Or is it fully weight-bearing? Is this reckless, or is there a scientific basis, I'm going to tell you about it now, and you pay attention to the animation on the screen. ”

An animated demonstration of the hip joint appeared on the screen, based on the CT 3D reconstruction, which completely simulated Professor Zhang's fracture at that time.

"You see, at that time, Professor Zhang's intertrochanteric fracture was shattered, and it was also a medial shatter. The stability of this fracture is completely supported by the medial cortical bone, which is the load-bearing wall, and now the medial side is shattered, so it is believed that it is impossible to walk with weight in the early postoperative period. Song Zimo quickly entered the focus of the problem.

The animation continues and is now a simulation of a fracture postoperative, with the conduction of gravity marked by red lines and arrows.

A few classmates, close to the desk with a snack, secretly reached out to grab a few candy to eat, and immediately retracted their hands, don't miss the knowledge points.

Song Zimo propped his hands on the podium: "This involves the knowledge of mechanics in orthopedics, that is, biomechanics. Most of us have only a sporadic grasp of biomechanics, if not even a sporadic mastery. If it weren't for the stimulation of this surgery, I wouldn't have realized how important biomechanics are to orthopedic surgery. But our Dr. Yang realized it and actively applied it to the surgery. ”

Song Zimo stepped down from the podium, turned his back to the screen, and walked between the lines. Yang Ping remembered that when he first came to the hospital, during the interview, this guy's arrogant posture was also like this, talking and walking between the lines.

"For this fracture to achieve early weight-bearing walking, two conditions must be met: anatomical reduction, which establishes conditions for bony support; Removes stress to reduce the burden on bony support. Look! Song Zimo turned around and faced the screen.

"Needless to say, the anatomical reduction has completely reduced several bone pieces, and everyone has no doubts. I'm just going to talk about the second one, shunt stress, and that's the focus of today, the application of biomechanics! "Song Zimo is very eloquent, and he turned a class into a speech.

Yang Ping's belly: I worked hard to do the operation, and this guy is cool on the podium.

The classroom was silent, and all the attention was concentrated on grasping the knowledge.

"In order to divert the stress, the tension band and the barrel hoop principle were used."

Tension belt everyone is familiar with ulnar olecranon fractures and patellar fractures are often done, turning tensile stress into compressive stress. This is the first time I've heard of this barrel hoop.

Someone started scratching their heads and necks.

"The outer steel cable is the tension belt, and the three steel cable rings that fix the fracture are the barrel hoops." Song Zimo returned to the podium, and the marker symbols turned into the mouse moved on the screen.

"Notice the animation, when the person walks upright, the normal gravity line, from the spine to the second sacral vertebrae, to the hip joint, from the femoral head down the lower limb gravity perpendicular."

The animation is extremely beautiful and intuitive, and the red gravity lines generally follow the route just mentioned.

"For ordinary simple intertrochanteric fractures, bony support can bear the weight, so simple trochanteric fractures, after anatomical reduction, PFNA fixation, can rest assured that you can walk with weight within 24 hours. But what if there is a comminuted intertrochanteric fracture and the bony support cannot bear the weight?"

What to do? Cold! I'm here to listen to the lecture, you ask me. Everyone's thinking was mobilized by Song Zimo.

"For gravity diversion, it's the best thing to do. Watch this animation. ”

It used to be a normal person's gravity conduction animation, but now it has been replaced by an animation of Professor Zhang's postoperative fracture model.

"Gravity starts from the femoral head and is divided into four routes, the bony support conducts part downward, the intramedullary nail conducts part downward, part of it is converted into the tension of the outer tension belt cable, and part of it becomes the expansion force of the three steel cable hoops. In this way, the bony support reduces the burden, avoids the displacement of the fracture, reduces the burden of the intramedullary nail, and avoids fatigue and fracture. ”

The animation is simple and easy to understand, with red gravity shunts, one down along the femoral backbone, one down along the intramedullary nail, and the two finally merge; The two red arrows of the outer steel cable ring are reversed along the steel cable, forming a downward pulling trend; Three steel hoops, surrounded by arrows, seemed to explode in all directions.

Understood, understood, everyone suddenly realized, and some people were still puzzled, and the audience began to talk to each other.

Dr. Jin and Director Tian sat together: "This is really ingenious, I usually have applications for steel cables, but I don't understand it so deeply, this requires a lot of familiarity with various parameters of bone blocks, steel cables, and intramedullary nails, so I dare to combine them like this, right?" The position thickness of the three steel cable rings should be very particular, especially when the ring is locked, the tightness of each ring is different? ”

Director Tian turned sideways and said, "You're right, the tightness of these three rings is different. In this way, under the action of compressive stress, ensure that the tip of the distal end of the medial main bone block is always slightly towards the medullary cavity to resist the notch, otherwise once it is towards the medullary cavity, it will not take long to slide out, and the hoop will fail. The mechanical knowledge contained in this operation is beyond the scope of the orthopedic surgeon's knowledge, Lao Jin, I have gained knowledge, it turns out that the steel cable can be used like this. ”

"This guy is a bit evil, Director Han's vision is too poisonous, I heard that he picked it up during the interview of this batch of newcomers." Dr. King said.

Director Tian smiled: "Do you remember? On his first day on the job, he embarrassed me, this guy, thanks to him, otherwise I would have really fallen into the pit. ”

Dr. Kim remembered, "You said that occult femoral neck fracture, I went out to a meeting that day, and I came back to listen to the doctor under me. ”

In private, Director Tian and Dr. Jin also talked about it, Dr. Jin is much older than Director Tian, although he is still the attending officer, but Director Tian respects him very much and does not see him as an attending officer at all.

There was a lot of discussion in the audience, and it was a mess, and everyone's cognition was a little swiped.

Everyone is in this profession and has received professional education, so there is basically no obstacle with such an explanation, plus an animated demonstration.

There are so many mechanical principles in orthopedic surgery, could Newton also study medicine? I really suspect that he was enlightened not because of apples, but because of broken bones.

Song Zimo banged on the podium, and the audience slowly quieted down: "I want to emphasize one point, the next similar operation, you will fail if you use the same method!" ”

When I asked this question, I just woke up and was confused again.

Song Zimo explained: "Why? If you don't master the principles of biomechanics, you can't achieve satisfactory results. The number, thickness, position, tightness, and intertwined structure of the ring steel cable are not placed casually, otherwise it will become an ordinary fixed ring, which cannot change the direction of force and maintain the stability of the fracture. ”

Is it so particular about a ring?

That tension band, everyone usually knows that ulna olecranon fractures and patellar fractures are often used, but I didn't expect this kind of wonderful use.

The steel cable ring is also used, isn't it sometimes pierced to fix the fracture? What kind of stress is converted?

What a headache!

Song Zimo asked everyone to be quiet again: "Now let's rest for ten minutes, eat something, and discuss it later." ”