This prospective case-control study measured TT-TGD in patients with isolated patellofemoral pain syndrome referring to radiology and orthopedic departments of Shariati Hospital (affiliated to Tehran University of Medical Sciences).
A total of 100 cases participated were divided into case (n=53) and control (n=47) groups.
The Patients in case group were selected from those with bone maturity (growth plate closure) and complain of pain in patellofemoral region for at least 6 months.
Patients were excluded from the study in cases of a history of major knee injury within the last six months,
clinical or radiological diagnosis of osteoarthritis,
inflammation of the patellar tendon,
bursitis or fat pad syndrome,
fracture,
history of knee surgery or arthroscopy,
obvious ligament or meniscus injury,
cartilage injury,
fluid accumulation in the joint and arthritis.
The control group were selected from those who experienced knee trauma and were referred due to knee pain; however,
there was no evidence of obvious instability of patella or knee in any of the anteroposterior,
axial,
and coronal plans in their clinical examination and a knee surgeon has recommended MRI in order to diagnose their clinical complaints. Moreover,
there should be no significant issue on the patients' MRI.
PFPS diagnosis in the patient group was confirmed based on the clinical history and examination by a knee surgeon.Follow obtaining the participant's consent,
information on age,
gender,
weight,
height,
and body mass index (BMI) were recorded.
In addition,
a visual analogue scale (VAS) was used to determine pain severity during the day.
MRI was performed in both control and case groups using a Siemens 1.5-T Avanto with a knee coil.
The MRI protocol included sagittal,
coronal,
and axial PD fat sat,
as well as T1WI coronal and axial and T2WI sagittal images.
The images were examined by a professional radiologist in terms of the presence or absence of knee and ligament injuries and arthritis.
TT-TGD was measured according to the standard methodology.
A vertical line was first drawn from the trochlear groove depth to the posterior condylar line at the axial cross section. .
Then with preserving the trochlear line by a cursure and transferring to the lower axial sections at tibial tuberosity level,
another vertical line was drawn from the anterior most prominent point of the tibial tuberosity parallel to transferred trochlear line and the distance between the two parallel lines (perpendicular to the tibial tuberosity and trochlear groove) was measured .
This line indicates the TT-TGD.
Data was analyzed using SPSS 22 (Chicago,
IL,
USA).
The Kolmogorov-Smirnov test was used to examine the normality of the values.
The student t-test and U-Mann-Whitney were used to compare the two groups accordingly.
Pearson's and Spearman's correlation coefficients were also used to examine the relationship between variables.
Regression analysis was used to provide a linear model.
In addition,
TT-TGD was randomly re-measured in 20 cases for intraobserver variability.
However,
they did not differ significantly from those measured earlier.