The incidence of trochlear dysplasia in anterior cruciate ligament tears

Abstract

Purpose The purpose of the present epidemiologic study is to record the radiographic presence of trochlear dysplasia and patella alta in patients who undergo anterior cruciate ligament (ACL) reconstruction as a potential underlying factor for postoperative anterior knee pain (AKP). Methods All consecutive cases of skeletally-mature ACLdeficient knees that would undergo ACL reconstruction in three different hospitals were prospectively included during a six-month period. Inclusion criteria were acute and subacute ACL injury with no previous ipsilateral knee operation. Patients with chronic ACL tears, prior-to-ACL-injury history of patellar instability or other PF disorders were excluded from the study. Results A total of 299 knees were included (mean age 32± ten years). Forty-four (14.7 %) knees had a positive 'crossing sign' in the lateral X-rays and 255 (85.3 %) had no sign of trochlear dysplasia (p<0.01). Among the cases with trochlear dysplasia, 41 (93 %) had type A trochlear dysplasia with the presence only of the 'crossing sign' and three (7 %) had type C trochlear dysplasia. Patellar height results included a mean Caton-Deschamps index of 1.0± 0.14 (0.5-1.4). Twenty (6.6 %) knees had an index of less than 0.8, and two (0.6 %) knees had an index less than 0.6. In contrast, 15 (5.0 %) knees had an abnormal value of more than 1.2, indicating patella alta. ConclusionsThe most important finding of the study is the increased prevalence of trochlear dysplasia and patella alta in patients with ACL injury, when compared to the incidence of trochlear dysplasia and patella alta in the general population in the literature. This finding could sound as an alert of a possible additional risk factor for post-operative anterior knee pain after ACL reconstruction.

Associations between Anterior Cruciate Ligament Injuries and Patella Alta and Trochlear Dysplasia in Adults Using Magnetic Resonance Imaging

“…22 Impaired trochlear morphology is increase the risk of early osteoarthritis following ACL reconstruction. 23 In 2014, Ntagiopoulos et al 6 attempted to record the incidences of both patella alta and trochlear dysplasia, which are the main patellofemoral disorders in patients who undergo ACL reconstructions, in a study of 299 patients using direct X-rays and the Caton-Deschamps index. They found 14.7% trochlear dysplasia and 5% patella alta, and they revealed that these could be possible additional risk factors for postoperative anterior knee pain.…”

“…disrupting the knee extension and flexion. 5,6 Two of the major morphological abnormalities that cause patellar instability are patella alta and trochlear dysplasia. Patella alta, or a "high-riding" patella, refers to a patella localized at a higher level above the trochlear fossa.…”

“…Ntagiopoulos et al described trochlear dysplasia as consisting of four different types, A through D, according to the crossing sign, double contour, and supratrochlear spur on true lateral radiographs. 6 Trochlear dysplasia is usually combined with patella alta, and PFIs are associated with multiple clinical problems, such as chondromalacia patellae and anterior knee pain. 8 In the literature, there are only two studies that have examined the relationship between ACL injuries and patella alta.…”

The Prevalence and Combined Prevalences of Anatomic Factors Associated With Recurrent Patellar Dislocation

“…The control group consisted not of asymptomatic volunteers but of patients evaluated for other injuries or conditions. Although previous studies have used similar control populations, possible confounding variables may exist, as highlighted by Ntagiopoulos et al, 22 who reported an increased prevalence of trochlear dysplasia and patella alta in patients sustaining anterior cruciate ligament injuries. Despite this, only 2 patients in the control group with a primary diagnosis of anterior cruciate ligament injuries were classified as having trochlear dysplasia.…”

The Evaluation of Trochlear Osseous Morphology: An Epidemiologic Study

“…In addition, we analyzed a superior number of specimens with good to excellent intra-and interrater reliability. In another study, Ntagiopoulos et al 24 investigated the prevalence of the trochlear dysplasia in 299 patients with anterior cruciate ligament (ACL) ruptures and reported it to be 14.7% (44 patients). The trochlear dysplasia was classified as type A in 93% and type C in 7% of patients.…”