This research focuses on 1 January 2015 to December 2018 to the undergraduate course to see a doctor and accept the lateral retinaculum extracapsular release of 100 patients were retrospectively study, through the follow-up, compare the preoperative and postoperative radiographic data, clinical manifestations, signs, etc., to evaluate the surgical effect and explore the pathogenesis of patellar lateral compression syndrome.

Excessive Lateral Pressure Syndrome (ELPS) is a series of clinical symptoms caused by various factors, such as patella tilt, adaptive contraction of the Lateral retinacular and unbalanced Pressure on the medial and Lateral joint surfaces of the patellofemoral. The concept was first proposed by Ficat in 1977. Patellofemoral pain syndrome has long been lumped together as widespread pregenitual pain and Patella malalignment syndrome as Patellofemoral pain due to poor Patella alignment.Kramer et al. found that the main cause of patellofemoral pain and increased pressure on the lateral patellofemoral surface was excessive pressure on the lateral retinaculum. Later, this view was accepted by more scholars, and lateral patellofemoral compression syndrome was gradually regarded as an independent syndrome and more studies were conducted.

In patients with lateral patella compression syndrome, early manifestations are usually pain in the soft tissues around the patella. Fulkerson et al. in 1985 found pathological changes in the nerve fibers in the lateral retinaculum through a pathological study, which is the basis for early lesions showing only pain in the soft tissues around the patella.As the disease progresses, uneven pressure on the medial and lateral facets of the patellofemoral joint will gradually lead to damage of the medial and lateral facets of the articular cartilage, eventually leading to irreversible damage of the articular cartilage and osteoarthritis.

The surgical treatment of lateral compression syndrome is varied, and in recent years, the most commonly used surgical methods include: incision lysis, percutaneous lysis, arthroscope-assisted percutaneous lysis, arthroscopic release, etc.These traditional surgical methods all have obvious complications, such as intra-articular dislocation of patella, recurrence of lateral compression due to postoperative adhesion of the support band, patellofemoral joint instability, intra-articular hematoma, etc.Although there are many surgical treatment methods for lateral compression syndrome, there is still no recognized standard treatment. Due to the fact that its effect and evaluation criteria cannot be unified, accurate horizontal comparison cannot be made among different regions and different populations.

Sports medicine, Peking University third hospital Guoqing Cui, a professor at the set of the lateral retinaculum extracapsular release, at the same time in the release of the lateral retinaculum complete retaining articular capsule and lateral patellofemoral ligament, this procedure can obviously improve patellofemoral joint trajectory anomalies and significantly reduce joint surface pressure, at the same time reduce the surgical trauma, try to keep the original structure,The complication of patellofemoral joint can be greatly reduced.

This research focuses on 1 January 2015 to December 2018 to the undergraduate course to see a doctor and accept the lateral retinaculum extracapsular release of 100 patients were retrospectively study, through the follow-up, compare the preoperative and postoperative radiographic data, clinical manifestations, signs, etc., to evaluate the surgical effect and explore the pathogenesis of patellar lateral compression syndrome.

Through this study, to explore the etiology, development and outcome of the disease, is helpful for the early diagnosis and treatment of the disease, avoid the irreversible injury of the patient's knee joint, greatly improve the quality of life of patients, reduce the incidence of knee replacement, and save medical resources.At the same time, the external capsule release of the lateral retinacular joint created by Professor Cui Guoqing will have a profound impact on the surgical treatment of the lateral retinacular joint.

Inclusion Criteria:

1. Age <40.
2. Normal lower limb strength line: no valgus or varus feet, no hyperpronation of hind feet, negative J sign.

Exclusion Criteria:

1. Combined patella instability and patella dislocation.
2. Have a history of knee surgery and knee fracture.
3. Complicated cruciate ligament injury and medial and lateral collateral ligament injury.
4. Osteoarthritis of the knee.

Young and middle-aged sports active people