Current Concepts Regarding Patellofemoral Trochlear Dysplasia

Levy, Benjamin J.; Tanaka, Miho J.; Fulkerson, John P.

doi:10.1177/0363546520958423

Cited by 39 publications

(28 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 Patellofemoral instability is most commonly observed during the first 30 of knee flexion, as the patella fails to engage fully with the trochlear groove. 7,8 The geometry of the trochlear groove is complex, as its shape and cross-sectional anatomy change along its length. The trochlear groove is studied using axial radiograph views introduced by Merchant to visualize patellofemoral contact areas at 30 and 45 of knee flexion.…”

mentioning

confidence: 99%

Reconceptualization of Trochlear Dysplasia in Patients With Recurrent Patellar Dislocation Using 3-Dimensional Models

Yu¹,

Cooperman

Schneble

et al. 2022

Orthopaedic Journal of Sports Medicine

Self Cite

View full text Add to dashboard Cite

Background: Common classification schemes, measurements, and surgical planning for trochlear dysplasia are predicated on 2-dimensional imaging views. Purpose: To investigate patellofemoral joint osseous anatomy using 3-dimensional (3D) printed models to describe osseous anatomic trochlear variations in patients with recurrent patellar dislocation. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Computed tomography scans were obtained from 20 patients with recurrent patellar dislocation and 10 healthy control knees, and 3D prints generated from these computed tomography scans were studied with respect to mediolateral positioning of the proximal trochlear groove and groove obliquity as well as changes in the appearance, height, and orientation of the medial and lateral trochlear ridges. Each trochlea was centered with respect to a vertical line perpendicular to the distal femoral condyles and through the central intercondylar notch roof, with the 3D models resting on their posterior femoral condyles. A novel 3D measurement method was devised to assess groove obliquity, termed the entry point–transition point (EP-TP) angle. The EP was defined as the midpoint of the flattened region of the proximal trochlea where the lateral and medial ridges of the proximal trochlea meet, and the TP was the point along the trochlear groove at which the groove shape changes from an oblique orientation proximally to one more vertical distally. Measurements were obtained by 3 reviewers, and reliability analyses were performed. Results: With the dysplastic knees arranged according to flattening of the trochleas, increased obliquity of the trochlear grooves was observed, as reflected by increased EP-TP angles as well as more lateral patellar EPs into the proximal trochleas of these recurrent patellar dislocation knees when compared with the control knees. The degree of trochlear dysplasia (according to the Dejour classification and trochlear flatness in the frontal and axial planes) was associated with diminished prominence of the lateral trochlear convexity, increasingly lateralized proximal trochlear EPs, increased trochlear groove obliquity, lateral trochlear curvature, and progressive medial ridge deformity. Conclusion: The 3D reproductions enabled unique conceptualization of trochlear deformity associated with recurrent patellar dislocation.

show abstract

mentioning

confidence: 99%

Reconceptualization of Trochlear Dysplasia in Patients With Recurrent Patellar Dislocation Using 3-Dimensional Models

Yu¹,

Cooperman

Schneble

et al. 2022

Orthopaedic Journal of Sports Medicine

Self Cite

View full text Add to dashboard Cite

show abstract

“…2,18,19,33,44 Trochlear dysplasia is characterized by a shallow or flat trochlear groove and the occasional presence of a hypoplastic or convex lateral condyle. 24 Trochlear dysplasia is present in up to 96% of patients with patellar instability and is a well-described risk factor for recurrent lateral patellar dislocation. 3,9,10,15,18,25,38,40 In the setting of trochlear dysplasia, it has been proposed that the addition of trochleoplasty is an available surgical option to correct the abnormal trochlear shape and restore patellar alignment within the trochlear groove.…”

mentioning

confidence: 99%

Ability of Medial Patellofemoral Ligament Reconstruction to Overcome Lateral Patellar Motion in the Presence of Trochlear Flattening: A Cadaveric Biomechanical Study

et al. 2021

View full text Add to dashboard Cite

Background: Medial patellofemoral ligament (MPFL) reconstruction is an established operative procedure to restore medial restraining force in patients with patellar instability. In the setting of a shallow sulcus, it is unclear whether an isolated MPFL reconstruction is sufficient to restore patellofemoral stability. Hypothesis: Progressively increasing the sulcus angle would have an adverse effect on the ability of an MPFL reconstruction to restrain lateral patellar motion. Study Design: Controlled laboratory study. Methods: Seven fresh-frozen human cadaveric knees were harvested and prepared for experimentation. Each specimen was run through the following test conditions: native, lateral retinacular release, lateral retinacular repair, MPFL release, MPFL reconstruction, and MPFL reconstruction with trochlear flattening. Four 3-dimensional printed wedges (10°, 20°, 30°, and 40°) were created to insert beneath the native trochlea to raise the sulcus angle incrementally and simulate progressive trochlear flattening. For each test condition, the knee was positioned at 0°, 15°, 30°, and 45° of flexion, and the force required to displace the patella 1 cm laterally at 10 mm/s was measured. Group comparisons were made with repeated measures analysis of variance. Results: In the setting of an MPFL reconstruction, as the trochlear groove was incrementally flattened, the force required to laterally displace the patella progressively decreased. A 10° increase in the sulcus angle significantly reduced the force at 15° ( P = .01) and 30° ( P = .03) of knee flexion. The force required to laterally displace the patella was also significantly lower at all knee flexion angles after the addition of the 20°, 30°, and 40° wedges ( P≤ .05). Specifically, a 20° increase in the sulcus angle reduced the force by 29% to 36%; a 30° increase, by 35% to 43%; and a 40° increase, by 40% to 47%. Conclusion: Despite an MPFL reconstruction, the force required to laterally displace the patella decreased as the sulcus angle was increased in our cadaveric model. Clinical Relevance: An isolated MPFL reconstruction may not be sufficient to restore patellar stability in the setting of a shallow or flat trochlea. Patients with an abnormal sulcus angle may have recurrent instability postoperatively if treated with an isolated MPFL reconstruction.

show abstract

“…After adjusting for confounding factors, most distance measurements in the RPD group, especially with Dejour type C femoral trochlea, were significantly increased compared with those in the control group. The results indicated that patients with medial trochlear dysplasia could be at risk not only of patellofemoral instability 26 but also of surface morphology alterations, including the osseous landmarks’ relative positions on the medial aspect.…”

Section: Discussionmentioning

confidence: 95%

Computed Tomography Imaging Analysis of the MPFL Femoral Footprint Morphology and the Saddle Sulcus: Evaluation of 1094 Knees

Chen

Xiong

Han

et al. 2022

Orthopaedic Journal of Sports Medicine

View full text Add to dashboard Cite

Background: The medial patellofemoral ligament (MPFL) has been reported to be anatomically attached from an osseous saddle region (saddle sulcus) between neighboring landmarks on the femur, including the adductor tubercle (AT), medial epicondyle (ME), and medial gastrocnemius tubercle (MGT). However, the position and prevalence of the saddle sulcus remain unknown. Purpose: To study the femoral footprint of MPFL and the prevalence of the saddle sulcus with computed tomography (CT) imaging; quantify the position of the saddle sulcus; and determine the relevant factors of the identified position and measuring distances. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 1094 knees in 753 patients were studied. Knees were organized into an anterior cruciate ligament reconstruction (ACLR) group (controls) and a recurrent patellar dislocation (RPD) group. Using 3-dimensionally reconstructed CT images, the authors determined the prevalence of the saddle sulcus and its position relative to the AT, the ME, the Schöttle point (1.3 mm anterior to the distal posterior cortex and 2.5 mm distal to the posterior origin of the medial femoral condyle), and the Fujino point (approximately 10 mm distal to the AT). Analysis of covariance was used to adjust for age, sex, side, and body mass index on the measurements. Results: There were 555 knees in the control group and 539 knees in the RPD group. The MPFL femoral footprint presented as an oblique, oblong, osseous region (saddle sulcus) in 75.7% of knees (75.0%, ACLR group vs 76.4%, RPD group; P < .001). The saddle sulcus was located a mean of 12.2 mm (95% CI, 12.0-12.4 mm) from a line connecting the apex of the AT to the ME (AT-ME) and a mean of 7.6 mm (95% CI, 7.5-7.8 mm) posteriorly perpendicular to that line. The location as a proportion of the AT-ME distance was 63.1% (95% CI, 62.6%-63.7%) in the X direction and 39.8% (95% CI, 39.1%-40.5%) in the Y direction. The Schöttle and Fujino points lay anterior and proximal to the saddle sulcus more than 5 mm away from the center of the saddle sulcus. Women had a higher prevalence of saddle sulcus (odds ratio [OR], 1.33 [95% CI, 1.00-1.75]; P = .046) compared with men. Conclusion: The saddle sulcus was identified in 75.7% of knees from the medial femoral aspect, with its center located consistently between the AT and ME.

show abstract

Current Concepts Regarding Patellofemoral Trochlear Dysplasia

Cited by 39 publications

References 89 publications

Reconceptualization of Trochlear Dysplasia in Patients With Recurrent Patellar Dislocation Using 3-Dimensional Models

Reconceptualization of Trochlear Dysplasia in Patients With Recurrent Patellar Dislocation Using 3-Dimensional Models

Ability of Medial Patellofemoral Ligament Reconstruction to Overcome Lateral Patellar Motion in the Presence of Trochlear Flattening: A Cadaveric Biomechanical Study

Computed Tomography Imaging Analysis of the MPFL Femoral Footprint Morphology and the Saddle Sulcus: Evaluation of 1094 Knees

Contact Info

Product

Resources

About