II.Risk factors for patella dislocation
III.Clinical manifestations and classification
IV. Treatment of patella dislocation (emphasis on the treatment of knee orthosis)
V.Guidelines for rehabilitation after dislocation of patella
 

1.OVERVIEW
Patella (also called the kneecap) is the body's biggest sesamoid bone, located in the front of the knee joint into the groove of the femur (also referred to as the femoral Trochlea a block and tackle the femoral groove), its role is to the strength of the quadriceps through the quadriceps tendon, patellar patellar tendon - tibial tubercle to the calf, in the process of knee flexion, patellar move up and down in the femoral block.When the patella completely moves out of this groove laterally, we call it a patellar dislocation, the most common of which is lateral dislocation of the patella.Acute traumatic patellar dislocation is the second most common cause of traumatic knee hematoma, after anterior cruciate ligament tears, accounting for about 3% of all traumatic knee lesions.
Acute traumatic patellar dislocation is usually caused by trauma sustained during physical activity or daily exercise, and is common in young people under the age of 20, accounting for about two-thirds of all cases.
In 93% of cases, acute non-contact sprains occur when the knee is flexed or valgus.
The intense displacement of the patellofemoral joint destroys the internal structure and stability of the patellofemoral joint, especially the damage of the patellofemoral ligament (MPFL) and patellofemoral cartilage located on the medial side of the patellofemoral joint (up to 95% of the time).
When the first acute traumatic patellar dislocation occurs, patients will experience knee pain, swelling, and limited activity. When the acute injury recovers, some patients will still have persistent knee pain symptoms, and some patients will show repeated patellar dislocation.
In the long term, joint cartilage damage and patellofemoral osteoarthritis may occur, resulting in limited movement of the knee, unable to return to the level of activity before injury, and in severe cases, daily life may be affected. A large number of literatures have reported the possible sequelae of acute patellar dislocation. For example, after the first patellar dislocation, the probability of re-dislocation is as high as 60%; Over the long term, more than 50% of patients will develop some degree of patellofemoral osteoarthritis.
 
II. Risk factors leading to patella dislocation
Patella dislocation is related to direct violent injuries such as knee sprain or direct collision to the knee during exercise. In addition, some developmental factors of patients themselves may also lead to patella dislocation. For example, high patella, femoral trochlea dysplasia, excessive lateral tilt of the patella, excessive external deviation of the tibial tuberosity, excessive anterior inclination of the femur, excessive external rotation of the tibia, genu valgus, genu hyperextension, or systemic ligament over-relaxation (multiple joint relaxation) are all risk factors for patella dislocation.
 
III. Clinical manifestations and classification
1. Acute patellar dislocation
Acute patellar dislocation due to trauma is typically characterized by rapid swelling around the knee joint and intense pain on the medial side of the patella.
After an acute dislocation of the patella, the patella is generally easier to reset.
Patella is often automatically reduced when the knee is straightened, and some patients need to be reduced by doctors in the emergency room. Rarely does patella continue to fail to be reduced.
 
2. Recurrent patella dislocation
Also called episodic dislocation, patients present with two or more episodic patella dislocations.
Dislocation often occurs in the knee near extension, with the knee reduced.
Generally after patella dislocation can be self-reduction, female more, patients are usually combined with lower limb dysplasia.
 
3. Habitual patella dislocation
Unlike recurrent patellar dislocation, habitual patellar dislocation often occurs in the kneecap position and occurs with each kneecap.
Patients often present with deformities in the appearance of the knee when bending the knee, and tension in the lateral structure of the patella. After forced reduction of the patella, it may lead to inability to bend the knee.
Unlike the upper patella, which is common in recurrent patella dislocation, the lower patella is often associated with habitual patella dislocation.
 
Iv. Treatment of patellar dislocation
Treatment for patellar dislocation varies with different types of patellar dislocation, and not all patients with patellar dislocation require surgical treatment.
To date, the literature has demonstrated that nonoperative treatment of acute primary traumatic patellar dislocation can achieve satisfactory clinical results.
For the first acute patellar dislocation, brace fixation is usually used for treatment.
Of course, for patients with surgical contraindication, the use of patella stabilization brace is an optional compromise.
 
Treatment of different types of patella dislocation:
1. Acute patellar dislocation (mainly supported fixation treatment)
For the first acute dislocation of the patella, a brace may be worn conservatively after diagnosis by a professional, in the absence of large loose bodies from cartilage fractures, and in the absence of severe patella instability.
 
A common orthosis (brace) for acute patellar dislocation
Including: knee orthosis: knee joint 0 degree extension fixed brake, bending Angle can not be adjusted, black knee support (finished product);
The long leg back cover (custom), knee limit fixation orthosis can be either extended or fixed at all angles, or it can be accurately adjusted to a range of motion for one incremental unit every 10° as required, allowing the patient to begin early motion.
 
The purpose of treating patellar dislocation with orthosis is to: Relieves pain and promotes detumescence
Promote the healing of patella medial structure scar, improve the stability of patella
Orthosis can be used for preoperative and postoperative fixation of patella dislocation, and also for fixation treatment of knee joint injury.
Note: When using orthoses:
Acute swelling is obvious, can do more ice compress;
The knee should be kept straight and the brace should be fixed for about 4 weeks before reexamination. During the fixed period, it is best to walk with weight on crutches.
After the knee brace is removed, knee movement can be practiced and muscle strength can be increased.
When walking with weight and participating in sports activities, patella dislocation brace is used to protect the patella from re-dislocation;
Try to avoid easy to cause patella dislocation action (such as knee flexion valveus or sharp turn, etc.) especially when squatting knees as far as possible to the sides of the separate
 
2. Recurrent patella dislocation
More common in children and adolescents, this dislocation is often associated with dysplasia of the patient's knee, most commonly lateral dislocation of the patella.
Surgery is generally recommended for patients with recurrent patellar dislocation.
For some patients who cannot undergo surgery, such as children with patent epiphysis, students facing high school or college entrance exams, patella stability brace (patella fixation band) can be worn for a short time to help stabilize the patella and prevent patella from dislocation again.
 
Orthosis after patellar dislocation
After patella dislocation, active rehabilitation and exercise are required without cast fixation. In this case, a convenient disassembly brace is the best choice for postoperative fixation.
At the same time, the brace also facilitates postoperative dressing change, wound observation, and continuous cold compress treatment.
There are two kinds of braces for postoperative wear:
One is the more commonly used knee brace fixation with unadjustable Angle of extension, which does not require too much postoperative knee fixation, and the use time is not long for about one month after surgery.
 
The other is to use the knee brace with adjustable knee Angle. The advantage of this brace is that it can control the knee bend Angle and facilitate postoperative walking.
Generally, patients with patellar dislocation begin to exercise weight-bearing walking one month after surgery. At this time, such braces can be worn for protection.
The results showed that the patella tilt orthosis and patella height were significantly lower with the adjustable Angle knee orthosis than without the knee orthosis when the knee was in an extended position and at 15° and 30° flexure.
In addition, the patients all said they were more inclined to be active early.
Early joint motion and moderate muscle strength training can reduce knee stiffness and improve joint proprioception.
 
The characteristics of the knee joint adjustable Angle clamping knee brace are:
The orthosis can also be used to fix the knee joint in the straight position after surgery, and the flexion Angle of the supported knee joint can also be gradually adjusted. While protecting the knee joint, the knee joint is allowed to move within a certain range, and the range of motion of the knee joint can be adjusted according to the postoperative rehabilitation of the patient under the evaluation of the doctor.
 
This orthotic design is very much in line with the concept of modern orthopaedic rehabilitation, which can help the patient return to the level of activity before the injury as much as possible, so that the recovered patient can enjoy their favorite sport or physical activity again.
 
Ubon suggests:
Patients can choose suitable knee orthoses according to their own needs.
For patients who need it, Ubon also offers two types of adjustable knee brace.
 
Special reminder:
Patients with sensitive constitution or in the skin inflammation stage should first wear their own cotton comfortable clothes when wearing the brace, and then wear the brace well to prevent the brace from causing discomfort to the skin.
For more attention, please go to the youbang public number to consult related information.
 
Guidebook for postoperative rehabilitation of patella dislocation
High quality rehabilitation program is an important part of successful recovery of knee function after patellar dislocation.
The early rehabilitation goal is to protect the postoperative wound healing and maintain the normal range of motion of the knee.
After the early stages, the focus of rehabilitation shifts to strengthening the entire leg and core.
In the final phase of rehabilitation, the focus is on individual motion-specific control, such as how to change direction or how to complete a rotation without damaging the knee.
 
It is important to note that the rate of postoperative rehabilitation progress will vary for each patient based on their age, related injury, pre-injury health, rehabilitation compliance, and injury severity.
Sports injury doctors and orthopaedic rehabilitation doctors should be followed to give a specific rehabilitation plan according to the specific surgical repair plan and clinical manifestations.