+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Increased Magnetic Resonance Imaging Signal of the Lateral Patellar Facet Cartilage: A Functional Marker for Patellar Instability?



Increased Magnetic Resonance Imaging Signal of the Lateral Patellar Facet Cartilage: A Functional Marker for Patellar Instability?



American Journal of Sports Medicine 45(10): 2276-2283



In the knee joint, predisposition for patellar instability can be assessed by an abnormal Insall-Salvati index, tibial tuberosity-trochlear groove (TTTG) distance, and abnormal shape of patella and trochlea. Given the complex anatomic features of the knee joint with varying positions of the patella during motion, the presence of a single or even a combination of these factors does not inevitably result in patellar instability. After trocheoplasty in patients with trochlear dysplasia, assessment of trochlear cartilage and subchondral bone is limited due to postoperative artifacts. Identification of presence of edema in the patellar cartilage may be helpful to identify patellar instability before and after surgery in these patients. To determine whether increased signal intensity of the lateral patellar facet cartilage or measurements of abnormal patellofemoral articulation are associated with patellar instability before and after trochleoplasty. Case series; Level of evidence, 4. Twenty-two patients with clinical diagnosis of patellar instability who underwent trochleoplasty, with magnetic resonance imaging (MRI) of the knee before and after surgery, were identified. The following observations and measurements were obtained in preoperative imaging: Insall-Salvati ratio, tibial tuberosity-trochlear groove (TTTG) distance, patellar shape (Wiberg), trochlear shape (Hepp), and edema in the lateral patellar facet cartilage. At 3 to 12 months after surgery, the presence or absence of edema in the cartilage of the lateral facet of the patella, the trochlear shape, and TTTG distance were reassessed. Wilcoxon matched-pairs signed rank test and Student t test were used. Interreader agreement was calculated as the Cohen κ or paired Student t test. Increased cartilage signal was present in 20 patients before trochleoplasty and in 4 after trochleoplasty. Insall-Salvati ratio was greater than 1.20 in 20 patients. Patellar shape was greater than type 2 in 18 patients. Trochlear shape was greater than type 2 in 21 patients before and 7 after trochleoplasty. Mean TTTG distance was 14 mm before and 10 mm after surgery. When results before and after surgery were compared, a significant difference was found for cartilage signal, TTTG distance, and trochlear shape. Agreement for observations was moderate to substantial, and no significant differences were found for interreader agreement ( P > .05). Patellar cartilage at the lateral facet of the patella can be assessed after trochleoplasty despite postoperative artifacts in the trochlea. A decrease of patellar edema seems to be associated with improved femoropatellar articulation. Moreover, patellar edema may be used as a functional criterion of patellofemoral instability. This would provide additional information compared to morphologic criteria which just describe predisposing factors for femoropatellar instability.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 059849952

Download citation: RISBibTeXText

PMID: 28510474

DOI: 10.1177/0363546517705634


Related references

Morphology and Anatomic Patellar Instability Risk Factors in First-Time Traumatic Lateral Patellar Dislocations: A Prospective Magnetic Resonance Imaging Study in Skeletally Immature Children. American Journal of Sports Medicine 45(1): 50-58, 2016

Degeneration of patellar cartilage in patients with recurrent patellar dislocation following conservative treatment: evaluation with delayed gadolinium-enhanced magnetic resonance imaging of cartilage. Osteoarthritis and Cartilage 17(12): 1546-1553, 2010

Patellar Height Measurements on Radiograph and Magnetic Resonance Imaging in Patellar Instability and Control Patients. Journal of Knee Surgery 30(9): 943-950, 2017

Cartilage status in knees with recurrent patellar instability using magnetic resonance imaging T2 relaxation time value. Knee Surgery, Sports Traumatology, Arthroscopy 23(8): 2292-2296, 2016

Incidence of second-time lateral patellar dislocation is associated with anatomic factors, age and injury patterns of medial patellofemoral ligament in first-time lateral patellar dislocation: a prospective magnetic resonance imaging study with 5-year follow-up. Knee Surgery, Sports Traumatology, Arthroscopy 2018, 2018

Quantitative magnetic resonance imaging in patellar tendon-lateral femoral condyle friction syndrome: relationship with subtle patellofemoral instability. Skeletal Radiology 2019, 2019

An analysis of patellar cartilage perfusion by dynamic magnetic resonance: its application to subjects with anterior pain of patellar origin. Revista Clinica Espanola 199(10): 641-646, 1999

Lateral patellar facetectomy and medial reefing in patients with lateral facet syndrome after patellar-retaining total knee arthroplasty. Journal of Arthroplasty 29(11): 2156-2162, 2015

Middle patellar tendon to posterior cruciate ligament (PT-PCL) and normalized PT-PCL: New magnetic resonance indices for tibial tubercle position in patients with patellar instability. Knee 25(5): 799-806, 2018

Effect of a patellar realignment brace on patients with patellar subluxation and dislocation. Evaluation with kinematic magnetic resonance imaging. American Journal of Sports Medicine 27(3): 350-353, 1999

Effect of a patellar realignment brace on patients with patellar subluxation and dislocation. Evaluation with kinematic magnetic resonance imaging. American Journal of Sports Medicine 28(1): 131-133, 2000

Lateral patellar retinaculum reconstruction for medial patellar instability following lateral retinacular release: a case report. Knee 21(1): 336-339, 2014

Association of patellar bone marrow lesions with knee pain, patellar cartilage defect and patellar cartilage volume loss in older adults: a cohort study. Osteoarthritis and Cartilage 23(8): 1330-1336, 2016

Magnetic resonance imaging of the infrapatellar fat pad: correlation with patellar articular cartilage abnormalities. Jbr-Btr 88(1): 1-6, 2005

Developmental Morphology in Childhood Patellar Instability: Age-dependent Differences on Magnetic Resonance Imaging. Journal of Pediatric Orthopedics 36(8): 870-876, 2015