# Effect of Rehabilitation Training Based on Automatic Extraction Algorithm on Knee Anterior Cruciate Ligament Injury Caused by Exercise

Authors: Sibo Zhu; Jie Gao
Journal: Scanning
 (2022)

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## Abstract

Objective. In order to explore the effect of rehabilitation training based on automatic extraction algorithm on knee anterior cruciate ligament reconstruction under arthroscopy.Methods. 81 patients with anterior cruciate ligament injury were randomly divided into observation group (42 cases) and control group (39 cases). The control group was given routine nursing, while the observation group was given rehabilitation training guidance based on automatic extraction algorithm. Lysholm score, HSS score, and range of motion of knee joint extension and flexion were used to evaluate the knee joint function before and after operation in the two groups. The quality of life of the two groups was evaluated by the concise health survey scale. The results showed that 50% of deep venous thrombosis occurred on the first day and 30% on the second day after operation. There was no significant difference in preoperative Lysholm score, HSS score, and knee flexion activity between the observation group and the control group (P>0.01). After 1-month, 5-month, and 1-year follow-up, the effective rate of knee function recovery in the observation group was significantly better than that in the control group. Lysholm score, HSS score, and knee extension and flexion activity were significantly different from those in the control group (P<0.01). The postoperative SF-36 quality of life score of the observation group was significantly higher than that of the control group, indicating that the quality of life of the observation group was significantly better than that of the control group. Therefore, early postoperative rehabilitation training guidance based on automatic extraction algorithm can improve local blood circulation and improve knee function and reduce pain, so as to promote the early recovery of patients.


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## Body

## 1. Introduction

Anterior cruciate ligament (ACL) injury is a common and serious knee joint sports injury, which is a common disease in the field of sports and rehabilitation medicine. If not treated properly, it will easily lead to knee joint instability, articular cartilage, and meniscus injury and even secondary osteoarthritis, which will seriously affect the functional activities of the knee joint and significantly reduce the quality of life of patients [1, 2]. At present, arthroscopic anterior cruciate ligament (ACL) reconstruction is the preferred method to improve the instability of the knee joint after anterior cruciate ligament rupture. This technique can accurately restore the stability of the knee joint. It has the advantages of less trauma, shorter operation duration, and faster postoperative recovery. Effective rehabilitation training after surgery can further consolidate the surgical effect and promote the recovery of patient knee function, but irregular functional exercise will lead to ligament relaxation or elongated ligament after reconstruction or even rupture, so that the ligament cannot play its due function and directly affect the surgical effect [3, 4].Anterior cruciate ligament injury occurs in children, adolescents, and adults. Once the ligament injury occurs, the knee joint function will be lost, resulting in instability of knee joint straight and rotation [5]. Arthroscopic ACL reconstruction has become the standard operation to repair the injured ligament and restore the knee joint activity [6]. However, ACL reconstruction can easily lead to muscle atrophy around the joint and severe cases complicated with joint stiffness, thus losing the opportunity of knee joint function recovery. Early postoperative knee function exercise is conducive to the recovery of knee joint function [7]. Compared with patients’ independent functional exercise, joint loosening and continuous passive movement (CPM) can simulate the natural movement of the human body to make the continuous passive movement of the affected limb and accelerate the recovery of articular cartilage and surrounding tissues. Hadzovic et al.’s study determines the effect of exercise regimen on preventing injury to knee hip ligaments and knee ligaments in young female basketball players. To collect existing studies on the impact of the research prevention program on ACL damage prevention by young female basketball players, the following electronic databases were searched: PubMed, Scindeks, Pedro, J-Gate, Doaj, and Google Scholar. The analyzed study was published from 2003 to 2018, and the participants were young women’s basketball players. According to the results of this study, the most commonly used training program is the neuromuscular program, whose structure includes several types of exercises and represents a combination of core strengthening exercises, strengthening lower limb muscles, agility exercises, flexibility exercises, and balancing exercises. Finally, the application of knee injury training programs leads to motor balance, sustained capacity balance, balance, flexibility, and biomechanical capabilities associated with ACL injury, thereby improving motor performance among female basketball players [8].Based on this study, 81 patients with arthroscopy were randomly selected and a control study was conducted. Rehabilitation training guidance based on automatic extraction algorithm and control study were performed, and the effect was satisfactory. It is now reported as follows.


## 2. Research Methods

### 2.1. General Information

81 patients with anterior cruciate ligament reconstruction under arthroscopy in a hospital were randomly selected as the research objects. Inclusion criteria are as follows: the patients had clear consciousness and had certain language communication ability. There was no history of drug dependence and mental illness. No serious complications such as heart, liver, and kidney were found. Informed consent was obtained from all participants [9]. There were 59 males and 22 females. The average age was 56.3 years (range, 14~72 years). Education level: 4 cases were illiterate, 7 cases were primary school, 45 cases were junior high school, 17 cases were senior high school (technical secondary school), and 8 cases were junior college or above. Marital status: 73 cases were married, 1 case was widowed, and 7 cases were divorced. Occupation is as follows: 46 workers, 21 farmers, and 14 cadres. The location of disease is as follows: left knee 48 cases and right knee 33 cases. The causes of injury are as follows: traffic injury in 39 cases, falling injury in 21 cases, and sports injury in 21 cases. There were 60 cases of simple anterior cruciate ligament injury, and there were 21 cases with joint injuries of medial meniscus, posterior cruciate ligament, medial collateral ligament, and lateral collateral ligament. There were 49 cases of acute injury and 32 cases of old injury. Clinical manifestations are as follows: knee joint swelling and pain with limited movement in patients with acute injury. Chronic injuries included knee pain, claudication, quadriceps atrophy, and limb weakness. The average length of stay was 8±05 days. The course of disease was 3-67.5 days (21±8 days). The selected cases were randomly divided into the observation group and control group, 42 cases in the observation group and 39 cases in the control group. There was no significant difference in age, gender, occupation, education level, lesion site, course of disease, operation method, and length of hospital stay between the two groups (P>0.05). This clinical trial was approved by the ethics committee of our hospital.


### 2.2. Method

#### 2.2.1. The Control Group Was Given Routine Nursing Care after Arthroscopic Anterior Cruciate Ligament Reconstruction

After the operation, the patient was not fully awake before the occipital supine position was removed, and the knee joint was elevated by 30 cm in the straight position, which was conducive to venous reflux and alleviating limb swelling, and the anterior cruciate ligament after transplantation was in the relaxation state with the minimum tension, so as to prevent the graft from shifting in the bone marrow tract; Elastic bandage was used to compress the knee joint, and sandbag was used to compress the knee joint; The vital signs, condition changes, sensory and motor function of the affected limbs, blood leakage of wound dressing, and quality and quantity of drainage fluid in wound cavity were closely observed; The self-made ice bag was used to completely close and cover the whole knee joint, and the ice compress lasted for 48-72 hours to achieve the effect of detumescence, hemostasis and pain relief. Targeted and personalized psychological care, diet guidance, symptomatic pain relief, health education, and functional exercise guidance were given [10].


#### 2.2.2. On the Basis of Routine Nursing in the Control Group, the Observation Group Was Given Rehabilitation Training Guidance Based on Automatic Extraction Algorithm

The first stage was 1 day to 2 weeks after operation. The patients were instructed to perform systematic functional exercises according to ABCDE on the same day after operation. The purpose of functional exercise at this stage is to relax and contract muscles, promote blood circulation of lower limbs, reduce swelling of limbs, avoid deep venous thrombosis of lower limbs, and prevent adhesion and muscle atrophy. ① Patella pushing: on the first day after the operation, the patients were pushed up and down in four directions, and ice was applied for 10 minutes immediately after the activity, once a day for 3 days. ② Isometric contraction of quadriceps femoris is as follows: thigh muscle group contraction and patella upward lifting, 10 seconds each time, 10 times in each group, 6-7 groups per day. In order to make the muscles strong, sandbags can be added 10 cm above the patella. ③ Hamstring isometric contraction is as follows: toe down and heel down, lift the thigh slightly, 10 seconds each time, 10 times in each group, 6-8 groups per day. ④ Straight leg raising: the knee joint should be straightened and lifted 10~15 cm away from the bed surface, 3 groups a day, 10 times in each group, 10 seconds each time, to strengthen the stability of the knee joint. ⑤ Assisted knee flexion (closed chain exercise): hold 10 cm above the knee with both hands, lift it up slowly, and slide the heel slowly backward along the bed, gradually increasing from 15° to 30°, 45° to 60°, and 75° to 90°. Patients can reach 90° at 2 weeks after operation and then maintain 90° until 4 weeks after operation. In addition, continuous passive exercise (CPM) was given twice a day from 1 week after operation. The initial degree of CPM was 30° and increased by 5° to 10° every day. The exercise lasted for 30 minutes each time and was adjusted according to the patient’s complaint.The second stage was 2-4 weeks after operation. Continue to strengthen the muscle strength training of the first stage and gradually increase the weight-bearing walking training and further strengthen the muscle strength exercise of the affected limb and the active flexion and extension of the knee joint: walk on the ground with the toe tip, walk on crutches 2 weeks after the operation, and step forward with the crutches on the same line with the toes to keep up with the healthy legs. Three weeks after the operation, walk on crutches on the ground, and the affected leg should step forward and land on the sole of the foot. At the same time, double crutches should be placed in the same line with the toes, and the healthy legs should keep up with them.The third stage was 4-6 weeks after operation. The purpose is to enhance the ability of knee joint motion control and strengthen various functional training. The range of motion of passive flexion and extension of joint should be 0° to 140°, and that of active knee joint should be 0° to 120°, in order to take off the crutch to walk, but should pay attention to avoid violent exercise and “stop and turn” and other actions. ① Walking gait practice: strengthen the lower limb muscle strength. From 4 to 6 weeks after surgery, gait training was strengthened to start walking under excessive double abduction protection to single abduction protection to 6 weeks after surgery, and the unbranch device walked normally. ② Stand against the wall: practice around the operation. The body stands against the wall, legs should be apart from shoulder-wide, and the tip becomes warped, 10 seconds per time, 10 times per group, 3 to 5 groups per day. ③ Squats against the wall: start exercising 4 weeks after surgery. The body should be against the wall, legs, and shoulder width, and the angle gradually increased (15, 30, 45, 60, 75, and 90); slowly slide down the calf to keep parallel to the wall, each action for 10 seconds, 10 times per group, 3 groups a day. ④ Up and down stair practice: practice up and down steps starting 5 weeks after the operation. When up the steps legs first, the bottom stable, knee straight after the leg up. When down the step, the leg first, heel steady, knee straight leg down. Each group lasted 10 times until the gait was normal and the activity stopped freely. ⑤ Arch step transfer: practice began 6 weeks after surgery. Angle gradually increased, with patient tolerance. Each was kept for 10 to 30 s, 10 each, 5 groups per day. So far, patients can work and live normally, and 8 weeks after practice fast walk, patients can walk in the swimming pool and can practice power bike, at 12 weeks, patients can practice jogging, rope skipping, and other activities and later gradually restore functional activities but should pay attention to avoid strenuous exercise and “emergency stop sharp turn” and other actions.


### 2.3. Rehabilitation Training Methods

Each kind of rehabilitation exercise is carried out under the supervision of professionals trained in rehabilitation medicine knowledge. The control group received routine rehabilitation training, including the following: (1) moderate joint range of motion training (2) According to the recovery of patients, different courses were carried out.The specific method is as follows: straighten the legs, then straighten the knee joint, and then exercise the quadriceps femoris. When reaching the apex, keep relaxing for a few seconds and then continue to repeat after 10~30 seconds, four groups of actions per day. In addition to routine rehabilitation training, the study group completed proprioception training, including the following: (1) straight leg lift, side leg lift, and back leg lift training. Straight leg raising exercise: fully extend the leg and raise the heel to 15 cm away from the bed, and keep it until exhausted,10 times/group, 2~3 groups/d. Side leg lifting exercise: lying on the side, the abduction angle of the affected thigh is 45° and maintained until exhaustion, 10 times/group, 2-4 groups/D, 30 s rest between groups. Back leg raising exercise: in prone position, the affected leg is straightened and lifted backward until the toe is 5 cm away from the bed surface, 20 times/group, 2-3 groups/D, with 30 s rest between groups. (2) Adjust the function of knee joint, move under the protection of brace, and carry out static squat exercise against the wall under the protection of brace. Practice method is as follows: back against the wall, feet apart, shoulder width, gradually forward, and the body center of gravity forms a distance of about 40~50 cm. At this point, the body has shown a squat posture, so that the long axis of the lower leg is perpendicular to the ground. The angle between thigh and calf should not be less than 90 degrees. According to the action essentials, squat quietly until the pain and swelling around the knee joint, rest for 30 s, and then squat again. Repeat for 30 minutes. The number of static squat exercises against the wall is 1~3 times/d.


### 2.4. Automatic Extraction Algorithm of the Anterior Cruciate Ligament of the Knee Joint

The key to the automatic extraction of the ACL of the knee is the need to identify the cavity surface triangular slices from the three-dimensional model data of the knee. The extraction process can be summarized as follows: first, a triangular sheet of the cavity boundary surface on the femur and the tibia is selected as seeds, and the lower end surface of the femur and the upper end surface of the tibia are initially extracted using regional growth method; then, the holes on the two boundary surfaces are automatically detected, these holes are repaired, and finally, the surface edges are photoed smoothly.


#### 2.4.1. The Intersection of the Normal Line and the Triangular Face Sheet Is Calculated

The intersection between the normal and adjacent anatomical structures is the condition for the selection of the seed, so the intersection of the normal triangular plane is calculated. This paper uses the method proposed by Moller and Trumbore to represent the vector as a basis point and directional vector as shown in formula (1):
(1)Lt=P+td¯.A spatial triangle is simply defined as an ordered array of verticesV0,V1,V2.For any pointQ within the triangle, we can represent the relative position of this point relative to the three vertices of the triangle as shown in Equation (2):
(2)Qu,v,w=wV0+uV1+vV2.Among these,u+v+w=1. Triples (u,v,w) are called the center of gravity coordinates of Q, which can represent all points of the plane where the triangle lies, but at least one point outside the triangle is a negative number. Because w=1−u+v, we represent u,v. By substituting Equation (1) into Equation (2), the intersection of the normal lines and the triangles is calculated as shown in the formula (3):
(3)P+td=1−u+vV0+uV1+vV2.This formula can be extended as shown in formula (4):
(4)−dV1−V0V2−V0tuv=p−V0.After obtainingt, u, and v by formula above, we can determine whether the intersection Q of the normal and the triangle plane falls within the triangle (not elsewhere where the triangle is): if 0 u1,0<v and v 1 and u+v1, the intersection Q falls within the triangle; otherwise, it is on the plane of the triangle, but outside the triangle.


### 2.5. Evaluation Method

Knee joint function score and Lysholm score were used to compare the knee joint function before and after operation. The extension and flexion range of motion was compared between the two groups before and after operation; SF-36 was used to compare the quality of life between the two groups. The knee joint percentage score system is the “gold standard” for the evaluation of knee joint function. The main contents of the study are as follows: extension and deficiency, whether brace is needed or not, and the degree of varus deformity. Among them, 6 items were scored items. The lighter the symptom was, the higher the score of each item was. The full score was 100 points. The higher the score, the better the functional rehabilitation.


#### 2.5.1. Lysholm Score of Knee Joint

As shown in Table1, concise health survey scale is widely used to measure the quality of life of general population. There are 36 items divided into 8 dimensions: physiological function, including 10 items: measuring whether health status hinders normal physiological activities; physiological function, including 4 items: measurement caused by physiological health problems, including 2 items: Measure the degree of pain and the effect of pain on daily activities; overall health, including five items: individual evaluation of their own health status and its development trend; vitality, including four items: measuring the subjective feelings of individuals on their own energy and fatigue; social function, including two items: measuring the impact of physical and mental health problems on the quantity and quality of social activities; emotion, including three items: measuring the limitation of functions caused by emotional problems; and mental health, including 5 items: measuring 4 kinds of psychology, health items are motivation, depression, behavior or emotion out of control, psychological subjective feeling, and a self-assessment of health change [11]. Each of the 36 items has 4~6 alternative answers representing different levels. According to different situations, give forward or reverse scores, first calculate the original scores, and then calculate the conversion scores with the standard formula. The higher the score, the lighter the functional damage, and the better the quality of life.Table 1
Lysholm score of knee joint.
Evaluation contentLimpNeed supportInterlockInstablePainSwellWalk up and down stairsSquat downScore5515252510105Evaluation criterionExcellent≥90 points; good 80~89 points; generally 70~79 points; <70 points difference


### 2.6. Statistical Analysis

The SPSS17.0 statistical software package is used for data processing, Chi-square test is used for counting data, andT-test is used for measuring data. P<0.05 is statistically significant.


## 2.1. General Information

81 patients with anterior cruciate ligament reconstruction under arthroscopy in a hospital were randomly selected as the research objects. Inclusion criteria are as follows: the patients had clear consciousness and had certain language communication ability. There was no history of drug dependence and mental illness. No serious complications such as heart, liver, and kidney were found. Informed consent was obtained from all participants [9]. There were 59 males and 22 females. The average age was 56.3 years (range, 14~72 years). Education level: 4 cases were illiterate, 7 cases were primary school, 45 cases were junior high school, 17 cases were senior high school (technical secondary school), and 8 cases were junior college or above. Marital status: 73 cases were married, 1 case was widowed, and 7 cases were divorced. Occupation is as follows: 46 workers, 21 farmers, and 14 cadres. The location of disease is as follows: left knee 48 cases and right knee 33 cases. The causes of injury are as follows: traffic injury in 39 cases, falling injury in 21 cases, and sports injury in 21 cases. There were 60 cases of simple anterior cruciate ligament injury, and there were 21 cases with joint injuries of medial meniscus, posterior cruciate ligament, medial collateral ligament, and lateral collateral ligament. There were 49 cases of acute injury and 32 cases of old injury. Clinical manifestations are as follows: knee joint swelling and pain with limited movement in patients with acute injury. Chronic injuries included knee pain, claudication, quadriceps atrophy, and limb weakness. The average length of stay was 8±05 days. The course of disease was 3-67.5 days (21±8 days). The selected cases were randomly divided into the observation group and control group, 42 cases in the observation group and 39 cases in the control group. There was no significant difference in age, gender, occupation, education level, lesion site, course of disease, operation method, and length of hospital stay between the two groups (P>0.05). This clinical trial was approved by the ethics committee of our hospital.


## 2.2. Method

### 2.2.1. The Control Group Was Given Routine Nursing Care after Arthroscopic Anterior Cruciate Ligament Reconstruction

After the operation, the patient was not fully awake before the occipital supine position was removed, and the knee joint was elevated by 30 cm in the straight position, which was conducive to venous reflux and alleviating limb swelling, and the anterior cruciate ligament after transplantation was in the relaxation state with the minimum tension, so as to prevent the graft from shifting in the bone marrow tract; Elastic bandage was used to compress the knee joint, and sandbag was used to compress the knee joint; The vital signs, condition changes, sensory and motor function of the affected limbs, blood leakage of wound dressing, and quality and quantity of drainage fluid in wound cavity were closely observed; The self-made ice bag was used to completely close and cover the whole knee joint, and the ice compress lasted for 48-72 hours to achieve the effect of detumescence, hemostasis and pain relief. Targeted and personalized psychological care, diet guidance, symptomatic pain relief, health education, and functional exercise guidance were given [10].


### 2.2.2. On the Basis of Routine Nursing in the Control Group, the Observation Group Was Given Rehabilitation Training Guidance Based on Automatic Extraction Algorithm

The first stage was 1 day to 2 weeks after operation. The patients were instructed to perform systematic functional exercises according to ABCDE on the same day after operation. The purpose of functional exercise at this stage is to relax and contract muscles, promote blood circulation of lower limbs, reduce swelling of limbs, avoid deep venous thrombosis of lower limbs, and prevent adhesion and muscle atrophy. ① Patella pushing: on the first day after the operation, the patients were pushed up and down in four directions, and ice was applied for 10 minutes immediately after the activity, once a day for 3 days. ② Isometric contraction of quadriceps femoris is as follows: thigh muscle group contraction and patella upward lifting, 10 seconds each time, 10 times in each group, 6-7 groups per day. In order to make the muscles strong, sandbags can be added 10 cm above the patella. ③ Hamstring isometric contraction is as follows: toe down and heel down, lift the thigh slightly, 10 seconds each time, 10 times in each group, 6-8 groups per day. ④ Straight leg raising: the knee joint should be straightened and lifted 10~15 cm away from the bed surface, 3 groups a day, 10 times in each group, 10 seconds each time, to strengthen the stability of the knee joint. ⑤ Assisted knee flexion (closed chain exercise): hold 10 cm above the knee with both hands, lift it up slowly, and slide the heel slowly backward along the bed, gradually increasing from 15° to 30°, 45° to 60°, and 75° to 90°. Patients can reach 90° at 2 weeks after operation and then maintain 90° until 4 weeks after operation. In addition, continuous passive exercise (CPM) was given twice a day from 1 week after operation. The initial degree of CPM was 30° and increased by 5° to 10° every day. The exercise lasted for 30 minutes each time and was adjusted according to the patient’s complaint.The second stage was 2-4 weeks after operation. Continue to strengthen the muscle strength training of the first stage and gradually increase the weight-bearing walking training and further strengthen the muscle strength exercise of the affected limb and the active flexion and extension of the knee joint: walk on the ground with the toe tip, walk on crutches 2 weeks after the operation, and step forward with the crutches on the same line with the toes to keep up with the healthy legs. Three weeks after the operation, walk on crutches on the ground, and the affected leg should step forward and land on the sole of the foot. At the same time, double crutches should be placed in the same line with the toes, and the healthy legs should keep up with them.The third stage was 4-6 weeks after operation. The purpose is to enhance the ability of knee joint motion control and strengthen various functional training. The range of motion of passive flexion and extension of joint should be 0° to 140°, and that of active knee joint should be 0° to 120°, in order to take off the crutch to walk, but should pay attention to avoid violent exercise and “stop and turn” and other actions. ① Walking gait practice: strengthen the lower limb muscle strength. From 4 to 6 weeks after surgery, gait training was strengthened to start walking under excessive double abduction protection to single abduction protection to 6 weeks after surgery, and the unbranch device walked normally. ② Stand against the wall: practice around the operation. The body stands against the wall, legs should be apart from shoulder-wide, and the tip becomes warped, 10 seconds per time, 10 times per group, 3 to 5 groups per day. ③ Squats against the wall: start exercising 4 weeks after surgery. The body should be against the wall, legs, and shoulder width, and the angle gradually increased (15, 30, 45, 60, 75, and 90); slowly slide down the calf to keep parallel to the wall, each action for 10 seconds, 10 times per group, 3 groups a day. ④ Up and down stair practice: practice up and down steps starting 5 weeks after the operation. When up the steps legs first, the bottom stable, knee straight after the leg up. When down the step, the leg first, heel steady, knee straight leg down. Each group lasted 10 times until the gait was normal and the activity stopped freely. ⑤ Arch step transfer: practice began 6 weeks after surgery. Angle gradually increased, with patient tolerance. Each was kept for 10 to 30 s, 10 each, 5 groups per day. So far, patients can work and live normally, and 8 weeks after practice fast walk, patients can walk in the swimming pool and can practice power bike, at 12 weeks, patients can practice jogging, rope skipping, and other activities and later gradually restore functional activities but should pay attention to avoid strenuous exercise and “emergency stop sharp turn” and other actions.


## 2.2.1. The Control Group Was Given Routine Nursing Care after Arthroscopic Anterior Cruciate Ligament Reconstruction

After the operation, the patient was not fully awake before the occipital supine position was removed, and the knee joint was elevated by 30 cm in the straight position, which was conducive to venous reflux and alleviating limb swelling, and the anterior cruciate ligament after transplantation was in the relaxation state with the minimum tension, so as to prevent the graft from shifting in the bone marrow tract; Elastic bandage was used to compress the knee joint, and sandbag was used to compress the knee joint; The vital signs, condition changes, sensory and motor function of the affected limbs, blood leakage of wound dressing, and quality and quantity of drainage fluid in wound cavity were closely observed; The self-made ice bag was used to completely close and cover the whole knee joint, and the ice compress lasted for 48-72 hours to achieve the effect of detumescence, hemostasis and pain relief. Targeted and personalized psychological care, diet guidance, symptomatic pain relief, health education, and functional exercise guidance were given [10].


## 2.2.2. On the Basis of Routine Nursing in the Control Group, the Observation Group Was Given Rehabilitation Training Guidance Based on Automatic Extraction Algorithm

The first stage was 1 day to 2 weeks after operation. The patients were instructed to perform systematic functional exercises according to ABCDE on the same day after operation. The purpose of functional exercise at this stage is to relax and contract muscles, promote blood circulation of lower limbs, reduce swelling of limbs, avoid deep venous thrombosis of lower limbs, and prevent adhesion and muscle atrophy. ① Patella pushing: on the first day after the operation, the patients were pushed up and down in four directions, and ice was applied for 10 minutes immediately after the activity, once a day for 3 days. ② Isometric contraction of quadriceps femoris is as follows: thigh muscle group contraction and patella upward lifting, 10 seconds each time, 10 times in each group, 6-7 groups per day. In order to make the muscles strong, sandbags can be added 10 cm above the patella. ③ Hamstring isometric contraction is as follows: toe down and heel down, lift the thigh slightly, 10 seconds each time, 10 times in each group, 6-8 groups per day. ④ Straight leg raising: the knee joint should be straightened and lifted 10~15 cm away from the bed surface, 3 groups a day, 10 times in each group, 10 seconds each time, to strengthen the stability of the knee joint. ⑤ Assisted knee flexion (closed chain exercise): hold 10 cm above the knee with both hands, lift it up slowly, and slide the heel slowly backward along the bed, gradually increasing from 15° to 30°, 45° to 60°, and 75° to 90°. Patients can reach 90° at 2 weeks after operation and then maintain 90° until 4 weeks after operation. In addition, continuous passive exercise (CPM) was given twice a day from 1 week after operation. The initial degree of CPM was 30° and increased by 5° to 10° every day. The exercise lasted for 30 minutes each time and was adjusted according to the patient’s complaint.The second stage was 2-4 weeks after operation. Continue to strengthen the muscle strength training of the first stage and gradually increase the weight-bearing walking training and further strengthen the muscle strength exercise of the affected limb and the active flexion and extension of the knee joint: walk on the ground with the toe tip, walk on crutches 2 weeks after the operation, and step forward with the crutches on the same line with the toes to keep up with the healthy legs. Three weeks after the operation, walk on crutches on the ground, and the affected leg should step forward and land on the sole of the foot. At the same time, double crutches should be placed in the same line with the toes, and the healthy legs should keep up with them.The third stage was 4-6 weeks after operation. The purpose is to enhance the ability of knee joint motion control and strengthen various functional training. The range of motion of passive flexion and extension of joint should be 0° to 140°, and that of active knee joint should be 0° to 120°, in order to take off the crutch to walk, but should pay attention to avoid violent exercise and “stop and turn” and other actions. ① Walking gait practice: strengthen the lower limb muscle strength. From 4 to 6 weeks after surgery, gait training was strengthened to start walking under excessive double abduction protection to single abduction protection to 6 weeks after surgery, and the unbranch device walked normally. ② Stand against the wall: practice around the operation. The body stands against the wall, legs should be apart from shoulder-wide, and the tip becomes warped, 10 seconds per time, 10 times per group, 3 to 5 groups per day. ③ Squats against the wall: start exercising 4 weeks after surgery. The body should be against the wall, legs, and shoulder width, and the angle gradually increased (15, 30, 45, 60, 75, and 90); slowly slide down the calf to keep parallel to the wall, each action for 10 seconds, 10 times per group, 3 groups a day. ④ Up and down stair practice: practice up and down steps starting 5 weeks after the operation. When up the steps legs first, the bottom stable, knee straight after the leg up. When down the step, the leg first, heel steady, knee straight leg down. Each group lasted 10 times until the gait was normal and the activity stopped freely. ⑤ Arch step transfer: practice began 6 weeks after surgery. Angle gradually increased, with patient tolerance. Each was kept for 10 to 30 s, 10 each, 5 groups per day. So far, patients can work and live normally, and 8 weeks after practice fast walk, patients can walk in the swimming pool and can practice power bike, at 12 weeks, patients can practice jogging, rope skipping, and other activities and later gradually restore functional activities but should pay attention to avoid strenuous exercise and “emergency stop sharp turn” and other actions.


## 2.3. Rehabilitation Training Methods

Each kind of rehabilitation exercise is carried out under the supervision of professionals trained in rehabilitation medicine knowledge. The control group received routine rehabilitation training, including the following: (1) moderate joint range of motion training (2) According to the recovery of patients, different courses were carried out.The specific method is as follows: straighten the legs, then straighten the knee joint, and then exercise the quadriceps femoris. When reaching the apex, keep relaxing for a few seconds and then continue to repeat after 10~30 seconds, four groups of actions per day. In addition to routine rehabilitation training, the study group completed proprioception training, including the following: (1) straight leg lift, side leg lift, and back leg lift training. Straight leg raising exercise: fully extend the leg and raise the heel to 15 cm away from the bed, and keep it until exhausted,10 times/group, 2~3 groups/d. Side leg lifting exercise: lying on the side, the abduction angle of the affected thigh is 45° and maintained until exhaustion, 10 times/group, 2-4 groups/D, 30 s rest between groups. Back leg raising exercise: in prone position, the affected leg is straightened and lifted backward until the toe is 5 cm away from the bed surface, 20 times/group, 2-3 groups/D, with 30 s rest between groups. (2) Adjust the function of knee joint, move under the protection of brace, and carry out static squat exercise against the wall under the protection of brace. Practice method is as follows: back against the wall, feet apart, shoulder width, gradually forward, and the body center of gravity forms a distance of about 40~50 cm. At this point, the body has shown a squat posture, so that the long axis of the lower leg is perpendicular to the ground. The angle between thigh and calf should not be less than 90 degrees. According to the action essentials, squat quietly until the pain and swelling around the knee joint, rest for 30 s, and then squat again. Repeat for 30 minutes. The number of static squat exercises against the wall is 1~3 times/d.


## 2.4. Automatic Extraction Algorithm of the Anterior Cruciate Ligament of the Knee Joint

The key to the automatic extraction of the ACL of the knee is the need to identify the cavity surface triangular slices from the three-dimensional model data of the knee. The extraction process can be summarized as follows: first, a triangular sheet of the cavity boundary surface on the femur and the tibia is selected as seeds, and the lower end surface of the femur and the upper end surface of the tibia are initially extracted using regional growth method; then, the holes on the two boundary surfaces are automatically detected, these holes are repaired, and finally, the surface edges are photoed smoothly.


### 2.4.1. The Intersection of the Normal Line and the Triangular Face Sheet Is Calculated

The intersection between the normal and adjacent anatomical structures is the condition for the selection of the seed, so the intersection of the normal triangular plane is calculated. This paper uses the method proposed by Moller and Trumbore to represent the vector as a basis point and directional vector as shown in formula (1):
(1)Lt=P+td¯.A spatial triangle is simply defined as an ordered array of verticesV0,V1,V2.For any pointQ within the triangle, we can represent the relative position of this point relative to the three vertices of the triangle as shown in Equation (2):
(2)Qu,v,w=wV0+uV1+vV2.Among these,u+v+w=1. Triples (u,v,w) are called the center of gravity coordinates of Q, which can represent all points of the plane where the triangle lies, but at least one point outside the triangle is a negative number. Because w=1−u+v, we represent u,v. By substituting Equation (1) into Equation (2), the intersection of the normal lines and the triangles is calculated as shown in the formula (3):
(3)P+td=1−u+vV0+uV1+vV2.This formula can be extended as shown in formula (4):
(4)−dV1−V0V2−V0tuv=p−V0.After obtainingt, u, and v by formula above, we can determine whether the intersection Q of the normal and the triangle plane falls within the triangle (not elsewhere where the triangle is): if 0 u1,0<v and v 1 and u+v1, the intersection Q falls within the triangle; otherwise, it is on the plane of the triangle, but outside the triangle.


## 2.4.1. The Intersection of the Normal Line and the Triangular Face Sheet Is Calculated

The intersection between the normal and adjacent anatomical structures is the condition for the selection of the seed, so the intersection of the normal triangular plane is calculated. This paper uses the method proposed by Moller and Trumbore to represent the vector as a basis point and directional vector as shown in formula (1):
(1)Lt=P+td¯.A spatial triangle is simply defined as an ordered array of verticesV0,V1,V2.For any pointQ within the triangle, we can represent the relative position of this point relative to the three vertices of the triangle as shown in Equation (2):
(2)Qu,v,w=wV0+uV1+vV2.Among these,u+v+w=1. Triples (u,v,w) are called the center of gravity coordinates of Q, which can represent all points of the plane where the triangle lies, but at least one point outside the triangle is a negative number. Because w=1−u+v, we represent u,v. By substituting Equation (1) into Equation (2), the intersection of the normal lines and the triangles is calculated as shown in the formula (3):
(3)P+td=1−u+vV0+uV1+vV2.This formula can be extended as shown in formula (4):
(4)−dV1−V0V2−V0tuv=p−V0.After obtainingt, u, and v by formula above, we can determine whether the intersection Q of the normal and the triangle plane falls within the triangle (not elsewhere where the triangle is): if 0 u1,0<v and v 1 and u+v1, the intersection Q falls within the triangle; otherwise, it is on the plane of the triangle, but outside the triangle.


## 2.5. Evaluation Method

Knee joint function score and Lysholm score were used to compare the knee joint function before and after operation. The extension and flexion range of motion was compared between the two groups before and after operation; SF-36 was used to compare the quality of life between the two groups. The knee joint percentage score system is the “gold standard” for the evaluation of knee joint function. The main contents of the study are as follows: extension and deficiency, whether brace is needed or not, and the degree of varus deformity. Among them, 6 items were scored items. The lighter the symptom was, the higher the score of each item was. The full score was 100 points. The higher the score, the better the functional rehabilitation.


### 2.5.1. Lysholm Score of Knee Joint

As shown in Table1, concise health survey scale is widely used to measure the quality of life of general population. There are 36 items divided into 8 dimensions: physiological function, including 10 items: measuring whether health status hinders normal physiological activities; physiological function, including 4 items: measurement caused by physiological health problems, including 2 items: Measure the degree of pain and the effect of pain on daily activities; overall health, including five items: individual evaluation of their own health status and its development trend; vitality, including four items: measuring the subjective feelings of individuals on their own energy and fatigue; social function, including two items: measuring the impact of physical and mental health problems on the quantity and quality of social activities; emotion, including three items: measuring the limitation of functions caused by emotional problems; and mental health, including 5 items: measuring 4 kinds of psychology, health items are motivation, depression, behavior or emotion out of control, psychological subjective feeling, and a self-assessment of health change [11]. Each of the 36 items has 4~6 alternative answers representing different levels. According to different situations, give forward or reverse scores, first calculate the original scores, and then calculate the conversion scores with the standard formula. The higher the score, the lighter the functional damage, and the better the quality of life.Table 1
Lysholm score of knee joint.
Evaluation contentLimpNeed supportInterlockInstablePainSwellWalk up and down stairsSquat downScore5515252510105Evaluation criterionExcellent≥90 points; good 80~89 points; generally 70~79 points; <70 points difference


## 2.5.1. Lysholm Score of Knee Joint

As shown in Table1, concise health survey scale is widely used to measure the quality of life of general population. There are 36 items divided into 8 dimensions: physiological function, including 10 items: measuring whether health status hinders normal physiological activities; physiological function, including 4 items: measurement caused by physiological health problems, including 2 items: Measure the degree of pain and the effect of pain on daily activities; overall health, including five items: individual evaluation of their own health status and its development trend; vitality, including four items: measuring the subjective feelings of individuals on their own energy and fatigue; social function, including two items: measuring the impact of physical and mental health problems on the quantity and quality of social activities; emotion, including three items: measuring the limitation of functions caused by emotional problems; and mental health, including 5 items: measuring 4 kinds of psychology, health items are motivation, depression, behavior or emotion out of control, psychological subjective feeling, and a self-assessment of health change [11]. Each of the 36 items has 4~6 alternative answers representing different levels. According to different situations, give forward or reverse scores, first calculate the original scores, and then calculate the conversion scores with the standard formula. The higher the score, the lighter the functional damage, and the better the quality of life.Table 1
Lysholm score of knee joint.
Evaluation contentLimpNeed supportInterlockInstablePainSwellWalk up and down stairsSquat downScore5515252510105Evaluation criterionExcellent≥90 points; good 80~89 points; generally 70~79 points; <70 points difference


## 2.6. Statistical Analysis

The SPSS17.0 statistical software package is used for data processing, Chi-square test is used for counting data, andT-test is used for measuring data. P<0.05 is statistically significant.


## 3. Result Analysis

This is the preoperative Lysholm score and HSS score between the knee function and the control group (P>0.05). The Lysholm score, HSS score, and the range of motion of extension and flexion in the observation group were significantly better than those in the control group at different periods after knee function operation, and the difference was statistically significant (P<0.01 and P<0.05), as shown in Tables 2–4.Table 2
Comparison of HSS function scores between two groups in different periods before and after knee joint operation (score,x¯±s).
GroupnPreoperativeAfter surgeryJanuaryMar.DecemberObservation group4242.13±10.3750.11±7.1168.01±5.184.64±3.31Control group3941.21±10.4347.31±6.6151.20±5.170.10±5.27Note: Compared with the control group at different time after operation,P<0.01.Table 3
Comparison of Lysholm function scores between the two groups at different times before and after knee joint operation.
GroupnPreoperativeAfter surgeryJanuaryMar.DecemberObservation group4248.1±4.362.1±2.165.1±3.484.6±3.04Control group3950.8±5.260.3±4.861.0±5.270.1±4.9Note: Compared with the control group at different time after operation,P<0.05.Table 4
Comparison of knee flexion and extension activity between two groups (x¯±s).
GroupnPreoperativeAfter surgeryJanuaryMar.DecemberObservation group4251.8°±5.8°85.5°±2.1°113.4°±7.5°130.4°±5.3°Control group3951.6°±6.4°83.1°±5.8°90.4°±13.1°111.4°±6.8°Note: Compared with the control group at different time after operation,P<0.05.The scores of SF-36 of life in the observation group were significantly higher than those in the control group, and the difference between the two groups was statistically significant (P<0.05), as shown in Figure 1.Figure 1
Comparison of postoperative quality of life between two groups.


## 4. Discussion

“Lingshu meridian tendon” said: “the knee is the house of tendons,” and the knee is the collection of the tendons, closely connected around the knee joint. The modern anatomy refers to ligaments, muscles, joint capsule, synovial sac, cartilage, and tendons, and the anterior cruciate ligament and meniscus are the category of traditional Chinese medicine called “tendon.” The tendon has the role of maintaining joint stability and maintaining joint function, such as “Class Sutra,” and the tendon said: “the tendon strength is rigid, so it can restrain the bone, strong movement,” and “impotence theory” said: “the main tendon bundle bone and benefit the organ also.” As recorded in the ancient documents, etc., keep the normal operation of the original tendon, and it needs sufficient qi and blood, and appropriate rehabilitation training can play the role of dredge meridians, sis and qi and blood, anterior cruciate ligament, and meniscus injury after patients, and the knee structure was damaged, leading to the reinforcement loss of qi and blood, tendon meridian obstruction, tendon and clonture, and joint stiffness.Rehabilitation training based on the automatic extraction algorithm is prone to knee anterior cruciate ligament injury caused by exercise, leading to knee joint instability, secondary joint cartilage, and meniscus wear and eventually causes joint degeneration and osteoarthritis, which seriously affects the joint function and then affects the patient’s work and quality of life. Arthroscopic knee ligament reconstruction is one of the main treatment methods for anterior cruciate ligament injury. It has the advantages of less surgical trauma, quick recovery of knee joint function, and less postoperative complications, but the final postoperative effect depends on the correct postoperative rehabilitation training [12, 13]. ACL mainly improves the stability and joint function of knee joint. It is required to bear weight, stretch, and bend and has good stability after operation. If postoperative rehabilitation nursing and early functional exercise are not appropriate, knee flexion and extension are often unsatisfactory, and the recovery of knee function is an important factor to evaluate the curative effect of ACL surgery [14]. Nonstandard functional exercise after ACL reconstruction can make the ligament after ACL reconstruction stretched, relaxed, or even broken, which cannot play its due role and seriously affect the surgical effect. The results showed that 50% of DVT occurred on the first day after operation. 30% occurred on the 2nd day after operation. Therefore, timely rehabilitation training guidance based on automatic extraction algorithm can improve local blood circulation, increase muscle strength around knees, prevent deep vein thrombosis of lower limbs, prevent adhesion and atrophy of joint capsule, soften scars, and increase joint mobility, thus preventing adhesion of tissues around joints, improving knee joint stability and joint function. Enhance ligament strength, restore muscle strength and balance ability of patients, promote functional rehabilitation, and significantly improve patients’ quality of life. It also plays a very important role in the stability of knee joint and the recovery of motor function after ACL reconstruction under arthroscope, which not only ensures the safety of ligament reconstruction but also restores the affected knee to normal range of motion and stability [15, 16].With the shift in biopsychological-social medical care mode and the gradual increase of patients undergoing arthroscopic anterior cruciate ligament (ACL) reconstruction, we need to further improve the quality of life while improving the functional activity of the knee joint. Lysholm score and HSS score as two current “gold standards” for knee function evaluation, their comprehensive evaluation can often better reflect the recovery of knee function of [17]. The results of this study show that there was no significant difference in the scores of preoperative Lysholm score, HSS score, and knee flexion activity between the observed and control patients (P>0.01). Follow up in January, May, and 1 year after surgery. The observation group each stage of knee function recovery was significantly better than the control group, and Lysholm scores, HSS scores, and knee flexion activity were compared with control groups. The differences were all statistically significant (P<0.01). Patients in the observed group had a significantly higher postoperative SF-36 QoL score than in the control group. The difference was statistically significant (P<0.01). It shows that the observed quality of life was significantly better than the control group [18].


## 5. Conclusion

To sum up, rehabilitation training based on automatic extraction algorithm is effective for patients with knee anterior cruciate ligament injury caused by exercise. It can effectively reduce knee dysfunction and reduce pain, so as to promote the early recovery of patients and can provide strong support for clinical treatment, suitable for clinical promotion.



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*Source: 8304071-2022-05-02.xml*