patella dislocation

BACKGROUND: Although the risk factors for patellofemoral dislocation are clearly defined, risk factors for osteochondral fracture (OCF) after patellar dislocation are not as well defined. The aim of this study was to investigate the risk factors for OCF by evaluating patients with and without OCF after first-time acute patellar dislocation. METHODS: This multicenter study was conducted as a retrospective examination of the radiologic measurements on the magnetic resonance imaging of 306 patients...

PURPOSE: To compare the pullout strength of a bio-inductive implant (BI) used to augment a medial patellofemoral ligament (MPFL) repair with the pullout strength of semitendinosus graft in a biomechanical cadaveric model. METHODS: Six matched pairs of cadavers (12 knees) were used in the biomechanical testing comparing semitendinosus tendon (Semi-T) versus a BI. The Semi-T was harvested from 1 of the matched pairs. A standard double-bundle technique using 2 sockets in the upper two-thirds of the patella 15 mm apart was performed...

Osteochondral fractures of the patella, also known as "flake fractures," frequently occur after patellar dislocation. In such fractures, a piece of patellar cartilage with subchondral bone breaks off due to patellar dislocation or subsequent reposition. Various surgical techniques have evolved for surgical therapy with the goal of realigning the patellar cartilage. This article presents a cost-effective surgical technique for achieving stable refixation of large osteochondral fragments in patellar flake fractures...

BACKGROUND: Epiphyseal, Vertebral, Ear, and Nose (EVEN)-PLUS syndrome is a rare condition characterized by the involvement of the Epiphyses, Vertebrae, Ears, and Nose, plus other associated findings, due to pathogenic variants in the HSPA9 gene. Due to the sparse number of patients, the clinical phenotypic spectrum is not clear. METHODS: We report two patients with pathogenic HSPA9 variants from a Chinese family. Besides the core clinical features of EVEN-PLUS syndrome, the two cases had seizures, developmental delay, and basal ganglia lesions in cerebral MRI...

BACKGROUND: Osteochondral injuries (OCIs) are common in patients with acute lateral patellar dislocation, which can produce both short- and long-;term adverse effects. However, the pattern of these injuries warrants further analysis, especially in relation to patient age. PURPOSE: To determine the overall prevalence of concomitant OCIs as well as the prevalence differences based on location and age after acute lateral patellar dislocations. STUDY DESIGN: Systematic review; Level of evidence, 4...

The incidence of articular injury, particularly osteochondral fractures (OCFs), has seen a cinnotable increase in recent years. Regardless of their location, fragments can be overlooked by plain radiographs, which might lead to osteoarthritis in the long run. Diagnostic imaging has a pivotal role in the assessment and classification of the fracture severity, as well as the presence of any associated dislocations. These fractures require surgical intervention for the restoration of joint function and the reduction of long-term complications...

Lateral patellar dislocations are the second most common type of traumatic knee injury, accounting for approximately 2-3% of cases, the most common being anterior cruciate ligament (ACL) injury. There are several well-documented anatomical risk factors predisposing to patellofemoral instability for example: patella alta, trochlear dysplasia, ligamentous laxity, and genu valgum. Co-existing medial collateral ligament injury in cases of patellar dislocations in the absence of ACL injury is uncommon and infrequently reported in the literature...

When planning an adolescent's primary surgery for recurrent patella instability, the surgeon must weigh the failure risk of performing medial patellofemoral reconstruction (MPFLR) versus the potential morbidity of adding a concomitant bony procedure, such as tibial tubercle osteotomy (TTO). In this age group, isolated MPFLR is an excellent operation with high clinical success, low failure rates, and favorable complication profile. Patients with high grade J-sign and severe trochlea dysplasia, apprehension into deep flexion, and extremes of bony malalignment, including elevated tibial tubercle-trochlear groove distance may benefit from "doing more" than MPFLR alone...

BACKGROUND: The medial patellofemoral ligament (MPFL) is the primary soft tissue restraint to lateral patellar translation and is often disrupted by lateral patellar dislocation. Surgical management for recurrent patellar instability focuses on restoring the MPFL function with repair or reconstruction techniques. Recent studies have favored reconstruction over repair; however, long-term comparative studies are limited. PURPOSE: To compare long-term clinical outcomes, complications, and recurrence rates of isolated MPFL reconstruction and MPFL repair for recurrent lateral patellar instability...

We present a rare case of open lateral condyle Hoffa's fracture with concurrent patellar intra-articular dislocation, quadriceps rupture and posterior cruciate ligament (PCL) avulsion. The early adolescent male sustained these injuries in a road traffic accident. Diagnostic evaluation and a multidisciplinary approach guided treatment decisions. The patient underwent single-stage open reduction and internal fixation for the lateral condyle Hoffa's fracture and quadriceps tendon repair, while conservative management was chosen for the PCL avulsion...

Patellar dislocation is a frequent sports-related knee injury. The primary restraint to lateral translation of patella is medial patellofemoral ligament. Several treatments for patella dislocation have been described in the literature. The purpose of this Technical Note is to describe the surgical technique for medial patellofemoral ligament reconstruction using gracilis tendon and 2 knotless soft anchors, avoiding patella tunneling.

Surgical intervention is the treatment of choice for recurrent lateral patellar instability. Surgery should be considered for first time lateral patella dislocations with osteochondral fractures or underlying anatomical risk factors. Primary repair and nonanatomical imbrications/reconstructions have fallen out of favor due to abnormal biomechanics and high rates of recurrence. Anatomical reconstruction of the MPFL using a variety of auto and allograft tissues have yielded good outcomes and low redislocation rates...

PURPOSE: To characterize the ability of the intact medial patellofemoral ligament (MPFL) and the adductor transfer and adductor sling MPFL reconstruction techniques to resist subluxation and dislocation in a cadaveric model. METHODS: Nine fresh-frozen cadaveric knees were placed on a custom testing fixture with the femur fixed parallel to the floor, the tibia placed in 20° of flexion, and the patella attached to a load cell. The patella was displaced laterally, and subluxation load (in newtons), dislocation load (in newtons), maximum failure load (in newtons), patellar displacement at failure, and mode of failure were recorded...

Different bone bruise patterns observed using magnetic resonance imaging (MRI) after non-contact anterior cruciate ligament (ACL) rupture and lateral patellar dislocation may indicate different knee injury mechanisms. In this study, 77 ACL ruptures and 77 patellar dislocations in knee MR images taken from patients with bone bruises at our institution between August 2020 and March 2022 were selected and analyzed. In order to determine typical bone bruising patterns following by ACL rupture and patellar dislocation, sagittal- and transverse-plane images were used to determine bone bruise locations in the directions of medial-lateral and superior-inferior with MR images...

CASE: We report the case of an 11-year-old boy with Ehlers-Danlos syndrome (EDC) who exhibited simultaneous medial and lateral patellar instability. The patient presented with a medial patellar dislocation, and subsequently, the patella became very unstable both medially and laterally. Despite distal realignment, the patellar instability was so significant that he underwent simultaneous reconstruction of the medial and lateral patellofemoral ligament using the semitendinosus tendon, with a good result...

(1) Background: Acute patella dislocation (APD) is a prevalent knee injury, with rates between 5.8-77.8 per 100,000. APD often results in repeat lateral patella dislocations due to the instability of the medial patellofemoral ligament (MPFL). Non-operative treatments have a 50% recurrence rate. While autologous grafting for MPFL has been favored, surgeons are now exploring synthetic grafts. We aimed to assess the effectiveness of synthetic grafts in MPFL reconstruction surgeries for repeated patellar dislocations; (2) Methods: Our research was based on a thorough search from the National Institute of Health and Clinical Excellence Healthcare Databases, using the Modified Coleman Methodology Score for quality assessment; (3) Results: Six studies met the inclusion criteria...

Osteochondral fractures of the lateral femoral condyle caused by lateral patella dislocation have been rarely reported. The AO/OTA Classification is not suitable for this uncommon injury. Comminution of the anterior cartilage surface of the lateral condyle with bone impaction is challenging to reduce and repair accurately, leading to uncertainty in joint function recovery. The treatment for this rare fracture is not commonly reported. We, herein, report a unique case where the lateral condyle osteochondral fracture occurred alongside patellar dislocation and instability of the patellofemoral joint...

Posterior stabilized total knee arthroplasty (TKA) has established itself as a highly effective design for total knee arthroplasty, renowned for its longevity and success. However, a subset of cases, approximately 6-12%, faces early failure, necessitating revision procedures. This case report presents a unique and previously undocumented complication involving a tibial post fracture following hyperflexion of the knee, masked by chronic patellar dislocation. This case highlights the importance of considering polyethylene wear-related failure in cases of instability without an apparent history of trauma...

Nail Patella Syndrome (NPS) is a rare genetic disorder with pathognomonic signs including dystrophic fingernails, iliac horns, and limb abnormalities, which commonly include hypoplastic development of the patellae, causing patients to experience patellar instability. This resulting patellar instability increases susceptibility to recurrent subluxations or dislocations in NPS patients. Since these anatomical abnormalities are present at birth or in childhood, early recognition may prevent the need for surgical intervention if appropriate preventive measures are taken...

Lateral patellar instability is one of the most common knee disorders among adolescents. Numerous anthropometric features, including trochlear dysplasia, patella alta, high tibial tubercle-to-trochlear groove distance, and coronal and rotational plane malalignment, are considered primary risk factors for patellar dislocation, and the understanding of their complex interplay is continuously evolving. Because of the multifactorial nature of patellar instability, there is a lack of consensus regarding many aspects of surgical intervention...