Defining the Role of the Tibial Tubercle–Trochlear Groove and Tibial Tubercle–Posterior Cruciate Ligament Distances in the Work-up of Patients With Patellofemoral Disorders

Objectives: Abnormal patellofemoral tracking has been implicated in patellar instability and can be influenced by the bony anatomy and alignment of the femoral trochlea, patella, and tibial tubercle. Tibiofemoral joint rotation has been recently suggested to play a role in patellofemoral kinematics but there has been little investigation of its contribution to patellar instability, including in pediatric and adolescent patients. Methods: A retrospective case-control design was utilized. 30 patients aged 9-18 with a prior patellar dislocation and an MRI of the involved knee were included. Cases were matched for age and gender with controls without patellar instability. Patients with ACL tears, tibial eminence or tubercle fractures, or prior surgery in the involved extremity were excluded. There was no difference in gender, age, height, but BMI was higher in the case group. MRI images taken with knee in extension were analyzed. Tibial tubercle-trochlear groove (TT-TG), tibial tubercle-posterior cruciate ligament (TT-PCL), and tibiofemoral rotation were measured. All measurements were performed by a single reader with excellent intra and interobserver reliability for tibiofemoral rotation (ICC-intra > .954 and ICC-inter > .905) demonstrated in a subset of patients. Results: The TT-TG was increased in patients with patellar instability at 16.3 mm compared to 10.9 mm in controls (p <.001) as was also the TT-PCL at 19.4 mm cases versus 17.6 mm (p=0.02). Tibiofemoral rotation was increased in patients with patellar instability with a mean 6.9° of tibial external rotation compared to 0.8° of tibial internal rotation in controls (p < .001). Overall, 30/41 (75.6%) of patients with patellar instability had tibiofemoral rotation >5° external rotation versus only 3/41 controls (7.3%). There was a strong correlation between TT-TG and tibiofemoral rotation (PCC = 0.776) and a moderate correlation between TT-TG and TT-PCL (PCC = .661). There was only a weak correlation between tibiofemoral rotation and TT-PCL. Conclusion: Increased tibiofemoral rotation is present in patients with patellar instability and may play a role in the pathophysiology of patellar instability. Increased tibiofemoral rotation can lead to an increased TT-TG even when TT-PCL is normal.

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The Role of Complete Posterior Cruciate Ligament Release in Flexion Gap Balancing for Total Knee Arthroplasty

The Journal of Arthroplasty ◽

10.1016/j.arth.2019.03.017 ◽

2019 ◽

Vol 34 (7) ◽

pp. S361-S365 ◽

Cited By ~ 3

Author(s):

Derrick A. Foge ◽

Todd H. Baldini ◽

Justin E. Hellwinkel ◽

Craig A. Hogan ◽

Michael R. Dayton

Keyword(s):

Total Knee Arthroplasty ◽

Posterior Cruciate Ligament ◽

Knee Arthroplasty ◽

Cruciate Ligament ◽

Gap Balancing ◽

Flexion Gap ◽

Total Knee

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How Do Axial Scan Orientation Deviations Affect the Measurements of Knee Anatomical Parameters Associated with Patellofemoral Instability? A Simulated Computed Tomography Study

The Journal of Knee Surgery ◽

10.1055/s-0037-1604141 ◽

2017 ◽

Vol 31 (05) ◽

pp. 425-432 ◽

Cited By ~ 1

Author(s):

Ran Xiong ◽

Cheng Chen ◽

Li Yin ◽

Xiaoyuan Gong ◽

Jiangming Luo ◽

...

Keyword(s):

Computed Tomography ◽

Cruciate Ligament ◽

Patellofemoral Instability ◽

Ct Scanning ◽

Tibial Tubercle ◽

Trochlear Groove ◽

Patellar Tilt ◽

Sulcus Angle ◽

Scan Data ◽

Anatomical Parameters

AbstractThe purpose of this study was to detect the correlation between axial scan orientation discrepancy and the knee anatomical parameters associated with patellofemoral instability during computed tomography (CT) scanning. CT scan data of 16 knees from 16 healthy subjects were retrieved. The reslicing processes were performed to simulate different axial scan orientations generated due to leg adduction/abduction during CT scanning. Eight parameters (tibial tubercle to trochlear groove [TT-TG], tibial tubercle to posterior cruciate ligament [TT-PCL], patellar tilt, lateral trochlear inclination, sulcus angle, trochlear depth, trochlear facet asymmetry, and trochlear condyle asymmetry) of five angles (neutral zero, 4/8 degrees of adduction and 4/8 degrees abduction) were quantified. All eight parameters showed varying degrees of deviations to the different axial scan orientations. TT-TG, patellar tilt, lateral trochlear inclination, and trochlear condyle asymmetry were relatively sensitive to axial scan orientation changes, whereas TT-PCL, sulcus angle, trochlear depth, and trochlear facet asymmetry were relatively insensitive. Although the sensitivities are various, surgeons should be aware of this situation and make necessary corrections.

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