Abstract
This study aims to compare the actual patellar tendon width with the skin and magnetic
resonance imaging (MRI) measurements and to describe a more accurate method to predict
the actual patellar tendon width before anterior cruciate ligament reconstruction
(ACLR).Thirty-nine patients undergoing primary ACLR were identified. Patients with
patellar tendon width of less than 30 mm by skin or MRI measurements were excluded
from the study. The actual patellar tendon width was measured as an intraoperative
reading taken after surgical exposure. Mean difference between the skin and actual
measurement and mean difference between the MRI and actual measurement was calculated.
Paired t-test was run to determine any significant differences. A difference was also calculated
between the actual measurement and the average sum of skin and MRI measurements for
each patient. Skin thickness was compared to Δ (Δ = preincision skin measurement of
patellar tendon width minus postincision actual measurement) by Spearman's correlation
test. Mean difference between skin and actual measurements was 2.5 mm, with p = 0.001. Mean difference between MRI and actual measurement was −2.7 mm with p = 0.001. However, the mean difference between the actual and the average sum of skin
and MRI measurements was 0.13 mm with p = 0.76. The Pearson's correlation coefficient, r
s, between average sum of skin and MRI measurements and the actual measurement was
0.6 with p = 0.001. There was no correlation found between the skin thickness and Δ∙. This study
indicates that there is a significant difference between the actual patellar tendon
width and the measurement of the tendon taken using a ruler on the skin or using MRI
image software. However, the average sum of skin and MRI measurements, which is not
significantly different from the actual width, can accurately predict the actual patellar
tendon width before ACLR. The study reflects level IV evidence.
Keywords
knee - ACL reconstruction - patellar tendon
