2021 ISAKOS Biennial Congress ePoster
Weight Bearing versus Conventional CT for the Measurement of Patellar Alignment and Stability in patients After surgical treatment for Patellar Recurrent Dislocation.
Giada Lullini, MD, PhD, Bologna ITALY
Claudio Belvedere, PhD, Bologna ITALY
Antonio Moio, MD, Bologna ITALY
Alberto Leardini, DPhil, Bologna ITALY
Eugenio Cammisa, MD, Bologna, Bo ITALY
MACCAFERRI BRUNA, MD, San Demetrio corone, Cosenza ITALY
Stefano Zaffagnini, MD, Prof., Bologna ITALY
Giulio Maria Marcheggiani Muccioli, MD, PhD, Associate Professor, Bologna ITALY
IRCCS Istituto Ortopedico Rizzoli - University of Bologna, Bologna, ITALY
FDA Status Cleared
Summary
Measurements of patellofemoral stability and alignment were found more consistent when obtained with weight-bearing CBCT compared to conventional CT.
ePosters will be available shortly before Congress
Abstract
Purpose
To compare weight-bearing cone-beam (CBCT) and conventional CT based measurements of patellofemoral alignment and stability in patients surgically treated for recurrent patellar dislocation. These scans implied respectively single-leg up-right posture, the knee flexed, and lower limb muscles activation, versus supine position with the knee extended.
Methods
17 patients (11 males / 6 females) after surgical reconstruction with fascia lata allograft for recurrent patellofemoral dislocation were analyzed at 60-months follow-up. Tilt and congruence angles, and tibial tuberosity-trochlear groove (TT-TG) offset were measured on images obtained from CBCT and conventional CT scans by three independent and expert radiologists. Paired t-tests were performed to compare measurements obtained from the two scans. Interrater reliability was assessed using a two-way mixed-effects model intra-class correlation coefficient (ICC).
Results
Only TT-TG offset was found significantly smaller (p < 0.001) in CBCT (mean 9.9 ±5.3mm) than in conventional CT (mean 15.9±4.9mm) scans. ICC for tilt and congruence angles and for TT-TG offset ranged between 0.80-0.94 with measurements in CBCT scans, between 0.52-0.78 in conventional CT.
Conclusion
In patients surgically treated for recurrent patellar dislocation, TT-TG offset was found overestimated with conventional CT. All measurements of patellofemoral stability and alignment were found more consistent when obtained with weight-bearing CBCT compared to conventional CT.
Study Design: Cross-sectional study; Level of evidence, 3.