Giada Lullini1,2, Claudio Belvedere1, Maurizio Busacca3, Antonio Moio3, Alberto Leardini1, Silvio Caravelli4, Bruna Maccaferri1,2, Stefano Durante3,5, Stefano Zaffagnini4,2, Giulio Maria Marcheggiani Muccioli6,7. 1. Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. 2. DIBINEM - University of Bologna, via di Barbiano, Bologna, Italy. 3. Radiologia Diagnostica Ed Interventistica, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. 4. II Clinica Ortopedica E Traumatologica, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. 5. Nursing Technical and Reahabilitation Assistance Service, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. 6. II Clinica Ortopedica E Traumatologica, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. marcheggianimuccioli@me.com. 7. DIBINEM - University of Bologna, via di Barbiano, Bologna, Italy. marcheggianimuccioli@me.com.
Abstract
PURPOSE: To compare weight-bearing cone-beam computer tomography (CBCT) and conventional computer tomography (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: A total of 17 patients (11 males/6 females) after surgical reconstruction with fascia lata allograft for recurrent patellofemoral dislocation were analyzed at 60-month 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. Inter-rater 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 ± 5.3 mm) than in conventional CT (mean 15.9 ± 4.9 mm) 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 and0.78 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.
PURPOSE: To compare weight-bearing cone-beam computer tomography (CBCT) and conventional computer tomography (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: A total of 17 patients (11 males/6 females) after surgical reconstruction with fascia lata allograft for recurrent patellofemoral dislocation were analyzed at 60-month 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. Inter-rater 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 ± 5.3 mm) than in conventional CT (mean 15.9 ± 4.9 mm) 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 and0.78 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.
Authors: Mark Hsiao; Brett D Owens; Robert Burks; Rodney X Sturdivant; Kenneth L Cameron Journal: Am J Sports Med Date: 2010-07-08 Impact factor: 6.202