Summary
Routine assessment of Patellofemoral dysplasia as a risk ACL injury should be considered to mitigate the risk through rehabilitation and other measures if possible.
Abstract
Introduction. Anterior Cruciate ligament (ACL) are among the most common sports medicine procedures the number is increasing in USA and the UK .
Numerous anatomic and neuromuscular control risk factors have been highlighted which can increase risk of ACL injury.
The Neuromuscular control explain higher incidence in female gender possibly due to posture and landing biomechanics. Core proprioception and strength, trunk displacement have been suggested . Additionally sports requiring cutting and pivoting maneuvers and landing after a jump are described.
Anatomically measures of bony geometry including decreased intercondylar femoral notch size, type and alpha angle, notch width and height index, ß angle ; shallow medial tibial plateau , increased slope of lateral tibial plateau etc.
Perhaps these factors apply differently to males and female genders and most likely act in combination under different intrinsic and extrinsic factors .
We present Patellofemoral (trochlear) Dysplasia( PFD) (mild to moderate) as a risk factor for ACL injury. The effects of Trochlear Dysplasia on Patellofemoral kinematics, Knee biomechanics and increased load on ACL are well established . Correlation of PFD with ACL injury has been described in literature sporadically.
Methods
In our combined military hospital, we set up a prospective observational cohort study with
Hypothesis
that Patellofemoral pathology could be a risk factor for ACL injury.
Roentgenographic evaluation of patellofemoral pathology requires true lateral view, which is difficult to obtain , hence we decided to use Magnetic resonance imaging (MRI)
• MRI classification 4 Grades D. Dejour
• Oswestry-Bristol Classification.
• Absolute MRI criterion for dysplasia, which have been standardized with high sensitivity and specificity for diagnosis.
Pfirrmann et al
Trochlear Facet Asymmetry ; Sensitivity 100%, Specificity 96%
Trochlear Depth. Sensitivity 100%, Specificity 96%.
Carrillon et al,
Lateral Trochlear Inclination. Sensitivity 93%, Specificity 87%.
Statistical analysis : The relationships between the different measures assessed with correlation statistics and linear regression. Spearman’s rank-order coefficients and point-biserial coefficients to assess correlations between continuous and dichotomous variables . Pearson Chi-square used for significance.
Results
;
Data collected on 487 consecutive isolated ACL Injury patients both Civilian and Military .MRI scan were reviewed by sports surgeons performing ACL reconstructions. There were 295 Military and 192 Civilians. All male , Ages from 21-44 years.
Axial and Sagittal MR images were evaluated to classify the patellofemoral pathology as per D.Dejour’s 4 grades on MRI ( A-to-D) and Oswestry-Bristol Classification.
In our cohort 63.4 % had some form of dysplasia as observed on MRI scans using D.Dejour four Grades. The percentages as are D.Dejour Grades A= 31.2 %. B= 19.5%. C= 9.6 % and D 3.1%.
Oswestry-Bristol Classification. 55.2% dysplasia. Normal; 44.8 Mild 30.9 % Moderate 21.4 % Severe 2.9 %.
The absolute MRI values of established dysplasia showed slightly higher values 5.3% of Severe Dysplasia compared to former two classifications.
Conclusions
and discussion: A Very high proportion 55.2% to 63.4% of patients who had ACL rupture requiring surgical reconstruction in our cohort had associated patellofemoral pathology. We conclude that it is a significant risk factor for ACL injury.