Key points of diagnosis and treatment of sports knee joint injury

Key points of diagnosis and treatment of knee joint sports injury

Knee joint injury can be divided into sports injury and car accident injury according to etiology; According to anatomy, it can be divided into bone injury, soft tissue injury and mixed injury. Simple bone injuries mainly include femoral condyle fracture, tibial plateau fracture and patella fracture. With the help of X-rays, the diagnosis is generally not difficult, and the treatment has the principle of AO diagnosis and treatment, which is relatively mature. The common sports injuries are mostly soft tissue injury, articular cartilage injury and bone contusion, which are generally not obvious on X-ray films. Missed diagnosis and misdiagnosis of these injuries by orthopedic surgeons who lack the foundation of sports medicine are not uncommon.

According to the author's experience in diagnosis and treatment, we should pay attention to asking the medical history, understanding the process of sports injuries, analyzing the mechanism of sports injuries, and combining with careful physical examination, most sports injuries can be relatively clearly characterized. If necessary, combined with CT, MRI and even KT-2000 knee joint measuring instrument, more accurate diagnosis and condition description can be obtained. KT-2000 knee joint measuring instrument can quantitatively judge the anterior and posterior stability of knee joint by measuring the anterior and posterior movement of tibial condyle under standard force, assist in judging the injury of cruciate ligament, and can also be used as an evaluation of joint stability after cruciate ligament reconstruction.

Physiological and anatomical characteristics of knee joint

The characteristics of the bone structure of the knee joint itself determine its poor stability, and its joint stability mainly depends on the soft tissue structure, including the static stable structure composed of cruciate ligament, lateral collateral ligament, joint capsule and meniscus and the dynamic stable structure composed of muscle system. In the case of violence, structures that maintain stable function, such as cruciate ligament and lateral collateral ligament, are easily damaged.

The knee joint includes two joint contact surfaces: the tibiofemoral joint surface and the patellofemoral joint surface. When walking, the maximum axial force of tibiofemoral joint in normal gait is 2.3 ~ 7. 1 times of body weight, and the stress of patellofemoral joint is 0.2 ~ 1.8 times of body weight, but it can be increased to about 1 1 times of body weight when running or jumping. Large stress load is easy to cause acute injury and chronic strain of articular cartilage and contusion of femoral condyle and tibial condyle structure.

The main movement of knee joint is flexion and extension. In the process of flexion and extension, there are some internal and external rotation, varus and front and back, internal and external displacement. At the same time, the femoral condyle will be accompanied by rolling and sliding, and the rotation axis of femur will change with the flexion angle, but it is generally believed that the axis of medial and lateral epicondyle of femur is the rotation axis of joint extension and flexion. When the knee joint flexes, the tibia rotates relative to the femur; On the contrary, when the knee joint is straightened, the tibia rotates outward relative to the femur. If the flexion and extension process is combined with excessive torsion, it is easy to cause knee joint injury, including ligament, meniscus and even articular cartilage tear. This can explain why the knee joint is the most vulnerable joint in the human body. The knee joint often bears a great weight load during exercise, and excessive exercise is easy to cause chronic strain, especially the strain of articular cartilage, which causes joint degeneration and pain.

meniscus injury

It can be divided into two categories: one is the injury caused by discoid meniscus deformity, which does not necessarily require a history of trauma, but most of them have the performance of knee joint snapping, accompanied by limited knee extension or knee joint pain, especially for teenagers under 20 years old, most of them are discoid meniscus injury, and there will be a large lateral space on X-ray film. The other is a common meniscus injury, which often has a history of sprain or jump injury. Meniscus injury is generally manifested as pain in the medial or lateral joint space. When walking for a long time, or during or after exercise, the pain is aggravated and relieved after rest. Depending on the pain site, there will be hyperextension pain or hyperflexion pain, which may be accompanied by slight swelling, compression or interlocking.

Physical examination: ① joint space pain can be pressed, but the skin itself is not painful; ② Hyperextension and flexion pain, severely limited flexion and extension range; ③ mcbride sign was positive; ④ The joints can be slightly swollen.

X-ray film is not helpful for diagnosis, and MRI can generally clearly show the location and degree of meniscus injury. Normal meniscus and cruciate ligament, whose hydrogen atoms are fixed on the dense network formed by peptides, can not participate in MR imaging, so they are low signal in any sequence. The most reliable MRI sign of meniscus tear is the visible discontinuity on the meniscus surface. Basically, it can be characterized by symptoms and signs, but it is difficult to judge the severity of the injury, and MRI can describe it better in morphology. Due to the protective effect of meniscus on knee joint, the treatment concept of meniscus injury has changed from? Excision of meniscus after simple injury? Become? Try not to remove it, try to keep it, try to sew it up, and even transplant it if possible? .

Anterior cruciate ligament injury

(1) must have a history of violent injuries, such as car accidents, wrestling, sprains, etc. Some patients can even hear when they sprain? Boom? The sound of ligament rupture. ② After injury, the blood vessels on the surface of cruciate ligament usually tear, which will lead to intra-articular bleeding and reach the peak of swelling that night or the next morning. In rare cases, the ligament is torn, but the synovial blood vessels are not torn or the swelling is not obvious. (3) Joint swelling after injury. After 3 ~ 4 weeks of rest, the swelling was obviously reduced and the good walking function could be restored. ④ After that, the unstable symptoms of anterior cruciate ligament injury appeared: the affected limb's motor ability decreased, he could not stop and turn sharply during exercise, he could not make a layup on one leg, he had difficulty running with the ball when playing football, he felt unable to eat hard things when going down the stairs, and he was worried about slipping on the road or walking in the snow, and even sprained many times. ⑤ Symptoms of secondary meniscus injury, such as pain and interlocking.

Physical examination: front drawer test is positive, lachman sign is positive, and axis shift test is positive.

X-ray film can indirectly indicate the injury of anterior cruciate ligament in a special case of small avulsion fracture (Segond fracture) at the outer edge of tibial plateau, and most of them have no positive manifestations. MRI manifestations of anterior cruciate ligament injury: high signal change of edema after acute injury, discontinuous tearing of top dead center, or absorption of stump after injury, and no cruciate ligament signal. High-quality MRI can diagnose anterior cruciate ligament injury with an accuracy rate of 97%. Experienced experts feel that 95% of cases can be correctly diagnosed through physical examination and medical history analysis. Nuclear magnetic resonance can provide useful help, but it is not necessarily a routine examination.

Posterior cruciate ligament injury

There must also be a history of external injuries, which can be sprains, kneeling injuries or traffic injuries. ② The injury was accompanied by joint swelling and pain, which improved after rest. ③ The posterior cruciate ligament has a certain self-healing ability after injury. According to the function of residual posterior cruciate ligament, chronic symptoms may be almost asymptomatic, painful and even obviously unstable.

Physical examination is relatively simple and specific: the back drawer test is positive, and some patients will appear false negative if there is some scar healing after local fracture or fracture.

MRI usually shows that the characteristic low signal contour of posterior cruciate ligament disappears or is interrupted, and a few show swelling. Two special types of anterior and posterior cruciate ligament injuries, namely avulsion fracture at the lower dead center of anterior and posterior cruciate ligament, have similar injury mechanism to cruciate ligament, and X-ray is easy to diagnose, while MRI and CT plain scan combined with three-dimensional reconstruction can locate the shape more clearly, which is a very beneficial supplement.

Arthroscopic reconstruction after cruciate ligament injury has become a routine, and the first choice for reconstruction is still autologous tissue, including autologous patellar tendon 1/3, hamstring muscle, achilles tendon and quadriceps femoris tendon, among which hamstring muscle is the most commonly used. In the case of multiple ligament injuries, allogenic tissues and artificial tendons can be used as supplements. Reconstruction methods are different from single tunnel reconstruction and double tunnel reconstruction. Double tunnel reconstruction has advantages in theory and biomechanical experiments, but in clinical follow-up, there is no significant difference between postoperative knee stability and patient's subjective satisfaction, and its advantages have not been recognized.

Injury of medial collateral ligament

① Caused by sprain or collision. ② Pain in the anatomical region of medial collateral ligament may be accompanied by some unstable symptoms with special manifestations. It is often difficult to cross your legs in the acute stage.

Physical examination: the anatomical part of the medial collateral ligament is obviously tender, and the fracture part is painful, which may be accompanied by local blood stasis. When everting, the medial collateral ligament area is painful, and the opposite side is accompanied by the opening of the medial space. When the cruciate ligament is injured, the sense of opening is greater, and even subluxation may occur. It is generally easy to diagnose according to symptoms and signs.

X-rays are generally of little help unless there is an avulsion fracture at the top dead center. MRI can clearly show local bleeding, edema and discontinuous manifestations, which is of great guiding significance for surgical repair of incision and determination of tear position.

Recurrent dislocation of patella

(1) The history of sprain with uncertain times can be sprain while running or wrestling while turning around. When wrestling, 1 sprain is accompanied by severe pain, and some patients can clearly point out that the kneecap runs to the outside; More than two sprains can cause swelling and mild pain, and some patients may be complicated with patellar cartilage or osteochondral fracture of lateral femoral condyle, followed by intra-articular fracture manifestations, including compression symptoms. ② Patients with chronic symptoms may suffer from joint sprain and pain caused by articular cartilage injury.

Physical examination: Patella fear test is positive, most of them are complicated with patella crush pain, and some patients may show pain caused by lateral impact of knee joint, sometimes it needs to be differentiated from lateral meniscus injury. Signs are the best diagnostic basis.

Physical examination: dislocation can be seen, but most of the patella has been reset during treatment, which is easy to become a factor of missed diagnosis; When there is osteochondral fracture, if the fracture piece moves to the intercondylar fossa and causes incomplete unbending, it is sometimes necessary to distinguish it from the avulsion fracture of anterior cruciate ligament (that is, intercondylar spine fracture). The fracture position of the former is relatively forward, and the bone block is easy to turn over, and some patients may have the performance of patella moving outward. MRI findings: tear of medial patellar retinaculum, fracture and tear of patellar cartilage and edema of lateral femoral condyle can be seen. The most reliable basis for the diagnosis of recurrent patellar dislocation is physical examination, that is, the patellar fear test is positive, and it is more reliable to bend your knees 30 degrees? Patella dislocation is caused by man, but serious injury is not recommended. MRI can clearly understand the location and severity of secondary patellar dislocation injury, but it is not helpful for qualitative diagnosis.

The knee extension device is damaged

The knee extension device includes quadriceps femoris, patella, patellar tendon and tibial tubercle, which plays a key role in kicking and knee extension. Patella fracture and tibial tubercle avulsion fracture are relatively easy to diagnose and treat. Fresh quadriceps femoris rupture and patellar tendon rupture need to be differentiated from simple soft tissue injury. The common performance after injury is that the knee can't be stretched out voluntarily, and the old wound scar may only be able to barely lift the straight leg after healing.

Physical examination: both of them have a feeling of emptiness under the patella. Patellar tendon rupture is empty, because it can't compress the tense patellar tendon, while quadriceps fracture is tensionless, because it loses muscle traction. However, patellar tendon rupture has obvious ultra-high patellar performance, while the patellar position of quadriceps femoris rupture is basically normal.

MRI can clearly identify the soft tissue structure and effectively display the fracture site, which has good diagnostic value. Repair, reliable anastomosis, full contact of tendon structure, effective tension reduction protection and postoperative rehabilitation are the keys to successful treatment. As for the tension reduction of internal fixation or external fixation, as long as it is firm, you can choose.

Bone contusion

Bone contusion refers to diffuse or localized congestion, edema and bleeding of bone marrow under the action of blunt force or overturning external force, with or without trabecular micro-fracture, but the bone contour has not changed and the bone cortex is intact, and the knee joint is the most common. Trauma such as knee ligament injury, acute meniscus injury, patella dislocation, etc. Usually occur together or separately. Because X-ray shows no abnormality, it is often diagnosed as soft tissue contusion in the past, but improper treatment often makes the pain linger.

MRI can well show the bleeding and edema of bone marrow, and it is easy to help determine the location and scope of bone contusion, which makes orthopedic surgeons and radiologists pay more and more attention to this disease. MRI showed that the bone contour was normal, the bone cortex was intact, and irregular patchy abnormal signals could be displayed in cancellous bone. Severe bone contusion around articular surface is often accompanied by different degrees of articular cartilage injury, which needs to be paid attention to by clinicians. Adequate fixation is very important for the treatment of bone contusion.

Generally speaking, we must pay attention to the inquiry of medical history, understand the process of sports injury and analyze the mechanism of sports injury. Combined with careful physical examination, most sports injuries can be characterized relatively clearly. If necessary, combined with CT, MRI and even KT-2000 knee joint measuring instrument, more accurate diagnosis and condition description can be obtained. Simply relying on X-ray diagnosis is easy to miss diagnosis and treatment.