Trochlea Morphology Research Articles

Trochlea morphology demonstrates variability but no gender difference in osteoarthritic patients undergoing total knee arthroplasty

BackgroundIn recent years, coronal lower leg alignment has received significant attention. Two classifications recently described the variability in both femoral and tibial morphology, resulting in differing native lower limb alignment.The native trochlea and the variability in morphology has received less attention. MethodsThis is a prospective cohort study of 200 patients undergoing robotically assisted TKA. Preoperative transverse CT scans were used to determine the posterior condylar axis (PCA), transepicondylar axis (TEA), lateral trochlear inclination (LTI), the sulcus angle (SA) and the anterior trochlear line (ATL). Outliers were defined as values > 1.5 IQR from median value. Trochlea dysplasia was defined as LTI < 12°. Gender differences were compared. ResultsIn total, 99 patients were female (49.4%). SA had a median of 137.0° (IQR 12°), ATL 4° (IQR 4), LTI 18° (IQR 7°). Median TEA-PCA was 5° external (IQR 3°). There were 5.0% outliers in SA, 3.0% of outliers in ATL, 3.5% outliers in LTI and 4.5% outliers in the TEA-PCA. Trochlear dysplasia was present in 11.5% of the measurements. There was no difference in any of the angles between the genders. ConclusionThe present study demonstrates no difference in trochlea morphology between the genders, rather a significant number of overall outliers in trochlear morphology. Larger cohorts but also, more investigations, are needed to better understand the trochlear morphology of patients undergoing total knee arthroplasty. The personalized alignment strategies and implants need to account for this variability in the population.

Abnormal femoral trochlea morphology is a risk factor for secondary injury of anterior cruciate ligament after reconstruction.

Secondary injury of the anterior cruciate ligament (ACL) is a common concern after anterior cruciate ligament (ACL) reconstruction, and identification of morphological risk factors is essential to prevent these injuries. We hypothesized that abnormal femoral trochlea morphology is associated with secondary ACL injuries after reconstruction. This study aimed to investigate the relationship between femoral trochlear morphology and secondary ACL injuries after reconstruction. A retrospective analysis was conducted on 20 patients who experienced secondary ACL injuries after reconstruction in our hospital between 2017 and 2022 (experimental group), and 40 patients were included in the control group. The following femoral trochlear characteristics were compared between the 2 groups: medial condylar height (MCH), trochlear sulcus height (TSH), lateral condylar height (LCH), trochlear sulcus depth (TSD), trochlear sulcus angle (TSA), medial trochlear inclination (MTI), and lateral trochlear inclination (LTI). The study found that patients in the secondary ACL injury after reconstruction group exhibited the following differences when compared to the control group: decreased MCH (56.33 ± 3.52 vs 59.93 ± 3.24, P value = .015), decreased TSD (4.89 ± 1.56 vs 6.98 ± 1.23, P value ˂ .001), decreased MTI (12.54 ± 6.57 vs 19.45 ± 6.35, P value ˂ .001), and increased TSA (145.23 ± 9.76 vs 139.25 ± 8.42, P value ˂ .001). This study demonstrated a significant correlation between abnormal femoral trochlear morphological characteristics and secondary ACL injuries after reconstruction. Decreased MCH, TSD, and MTI along with increased TSA are associated with a higher risk of secondary ACL injury. These data could thus help identify individuals susceptible to secondary ACL injuries after reconstruction.

Computed Tomographic Measurements of the Sulcus Angle of the Femoral Trochlea in Small-Breed Dogs with and without Medial Patellar Luxation.

Trochleoplasty is often performed in dogs with medial patellar luxation (MPL); however, the current guidelines on when to perform a trochleoplasty in dogs are vague. The sulcus angle (SA) is used to assess the femoral trochlear morphology in humans. The aim of this study is to describe a method to measure the SA and other parameters of trochlea morphology in dogs using computed tomography. First, we searched for a suitable measuring location for the SA. Transverse images of the femurs were obtained as perpendicular planes to the tangent of the femoral trochlea which was 0 to 60 degrees (every 5 degrees) to the anatomical axis of the femur. The deepest point of the femoral trochlea was found in the transverse images perpendicular to the tangent of the femoral trochlea which was at 15 degrees to the anatomical axis of the femur. The SA and the other parameters of femoral trochlea morphology were measured at the deepest point of the femoral trochlea. The SA of the stifle joints with grade 3 and 4 MPL was significantly higher than the SA of stifle joints not affected by MPL. There was no significant difference in the SA between dogs affected by grade 1 and 2 MPL and dogs not affected by MPL. Further studies are needed to establish whether the SA can be used as selection criteria for trochleoplasty.

Use of a Superolateral Portal and 70° Arthroscope to Optimize Visualization of Patellofemoral Tracking and Osteochondral Lesions in Patients With Recurrent Patellar Instability

Surgical treatment of patellofemoral instability and associated cartilaginous lesions can be technically challenging. Visualization of patellar tracking and underlying osteochondral lesions is paramount to operative success. To treat these conditions effectively, a comprehensive arthroscopic assessment of the patellofemoral joint as well as dynamic visualization of patella tracking must be achieved. Visualization of the patellofemoral joint—in particular, the articular cartilage of the patella and trochlea morphology—can be difficult when using traditional anteromedial or anterolateral portals and a 30° arthroscope lens. The technique described here uses an accessory superolateral portal and a 70° arthroscope to achieve significantly improved visualization of the patellofemoral articulation, in particular the chondral surfaces. This vantage point aids the surgeon in effectively evaluating patellar tracking, trochlea morphology, and importantly, osteochondral lesion location to help guide treatment algorithms in the patellofemoral joint.

Gender differences in femoral trochlea morphology.

This study aimed to analyze the morphology of the anterior femoral condyle using a quantitative three-dimensional reconstruction method. The morphological data were compared between genders. Computed tomography scans of femurs were taken from 90 healthy subjects and then reconstructed in 3D modeling software. Coaxial cutting planes were created at 10° increments to measure the lateral and medial anterior condylar heights (LACH and MACH, respectively), lateral and medial trochlear groove widths (LTW and MTW, respectively), and for trochlear groove tracking. The absolute values and normalized data were compared between male and female subjects. The sulcus angle and deepest point of the trochlear groove at each cross-section were also analyzed to determine the differences in the depth of the trochlear groove. The absolute dimensions of LACH, MACH, LTW, and MTW were significantly smaller in the female subjects, by 10.5%, 36.9%, 10.3%, and 11.0%, respectively, than in the males (p < 0.05). After normalization, no significant difference was found in the condylar height between the genders. However, the female subjects had a significantly larger value of approximately 7.9% for the normalized trochlear width. Male subjects had greater condylar heights and widths than the female subjects. Although the trajectory of the trochlear groove varied greatly among the subjects, the trochlear groove appeared to be wider and shallower in the female subjects than in the male subjects. These results provide important information for the design of femoral trochlea to fit Asian female patients. III.

Associations of trochlea morphology and patellofemoral alignment with prevalent radiographic patellofemoral osteoarthritis

To investigate the relation of trochlea morphology and patellofemoral alignment to prevalent radiographic patellofemoral osteoarthritis (PFOA). A within-person knee-matched case-control study was performed. Participants with unilateral radiographic PFOA were selected from the Multicenter Population-based Osteoarthritis Study (MPOA) in three towns in northern China that was approved by Peking University Health Science Center Ethics Committee (2018PHB166-01). Radiographic PFOA, radiographic tibiofemoral OA, sulcus angle, patellofemoral index and patella displacement were assessed using posterio-anterior and skyline views of the knee. We classified sulcus angle, patellofemoral index and patella displacement into quarters and investigated the relation of each of these measures to prevalent radiographic PFOA. Among 451 participants (mean age: 65.2 years, women: 66.8%) with unilateral radiographic PFOA, a reverse J-shaped relationship was observed between sulcus angle and prevalent radiographic PFOA (P=0.039 for quadratic term). Both higher patellofemoral index and patella displacement were associated with higher prevalent radiographic PFOA. Adjusted odds ratios (ORs) of prevalent radiographic PFOA in the highest quarter of patellofemoral index and patella displacement were 4.69 and 3.60 (Pfor trend <0.001), respectively, compared with the lowest quarter of each measurement. A similar relationship was observed between sulcus angle with either prevalent radiographic lateral or medial PFOA. Higher values of patellofemoral index and patella displacement were statistically significantly associated with higher prevalent radiographic lateral (ORs=5.07 and 4.59, respectively), but not medial PFOA (ORs=0.58 and 0.76, respectively). Extreme sulcus angles as well as higher values of patellofemoral index and patella displacement were associated with higher prevalent radiographic PFOA.

Clinical mid- to long-term outcome after autologous chondrocyte implantation for patellar cartilage lesions and its correlation with the geometry of the femoral trochlea

BackgroundThe aim was to investigate the clinical results after autologous chondrocyte implantation (ACI) at the patella in a mid- to long-term course, and whether trochlear dysplasia has an influence on the outcome. MethodsInclusion criteria were ACI for focal patella cartilage defects and preoperative magnetic resonance imaging (MRI). Patients with previous trochleoplasty or osteotomy have been excluded. Trochlea morphology was evaluated by sulcus depth, sulcus angle, lateral condyle index (LCI) and Dejour's classification for trochlea dysplasia. The clinical outcome was evaluated by a questionnaire including the Kujala- and IKDC-Scores. Survival of the ACI was analysed by the Kaplan–Meier method. A correlation analysis between morphologic parameters and clinical scores was performed. ResultsSeventy-eight patients (mean age 33.2 ± 10.7 years) were included (mean follow-up 6.5 ± 3.4 years). The mean sulcus depth was 5.0 ± 1.6 mm (normal value ≥5 mm), the mean sulcus angle was 153.4 ± 9.0° (normal value ≤145°) and the mean LCI was 84.9 ± 7.5% (normal value ≥90%). Major trochlea dysplasia (grades B–D) was seen in 29 patients (36.7%). Five-year survival rate was 98%, satisfaction-rate was 78.9% and the mean clinical scores were 67.6 ± 20.2 for the Kujala-Score and 64.7 ± 20.2 for the IKDC-Score. A lower LCI showed significant correlation with a lower IKDC score (r = 0.25; p = 0.037). ConclusionsThe present study reports an excellent survival rate and a good satisfaction rate in a mid- to long-term course after patella ACI. The clinical scores show a high variance and there is evidence that a pathologic trochlea correlates with inferior results.

Objective quantification of trochlear dysplasia: Assessment of the difference in morphology between control and chronic patellofemoral instability patients

BackgroundTrochlear dysplasia is an important risk factor associated with patellofemoral instability, but it remains difficult to classify with consistency. Currently there is no objective way to quantify the dysplasia. The purpose of this study is to define and quantify objectively the trochlear morphology by volume and length via computed tomography (CT). MethodsOne-hundred control patients (136 knees) were retrospectively reviewed and compared to 36 consecutive patients (72 knees) who were treated surgically for recurrent patellar instability and known trochlear dysplasia based on a lateral radiograph. Trochlear morphology was analyzed from a pre-operative CT and data presented as trochlear sulcus volume trochlear length. To determine where along the trochlear length dysplasia is most variable, the trochlear length was radiographically divided into thirds, volume was quantified along that section and compared to control trochlear. ResultsA significant difference in trochlear morphology exists between cohorts, volume (1.98 vs 3.77cm3) and length (31.97 vs 34.66mm) (p<0.05). However, there appears to be a gender based difference in trochlea morphology. The trochlea volumetric analysis between the female cohorts (L: 2.02cm3 vs. 2.94cm3, R: 1.95cm3 vs. 2.93cm3) demonstrated significantly less volume in instability patients (p<0.001). The proximal third of the trochlear contributed the majority of dysplasia difference determined by comparing mean trochlear volume, 95% of the difference. This difference decreased in distal sections, 53% and 32% respectively. ConclusionThis reproducible technique can be used to quantify the trochlea morphology, in order to describe the severity of a dysplasia.

Association between lateral patellar osteoarthrosis and knee morphology and alignment in young adults

To assess whether patellar and trochlea morphology and patellar alignment are associated with lateral patellar osteoarthrosis/chondrosis (OAC) in young adults. Magnetic resonance imaging (MRI) images of 183 subjects (81 cases, 102 controls) aged 21-35 years of age were evaluated. Quantitative measurements of patella and trochlea morphology and patellar alignment were obtained. Axial and sagittal MRI images were reviewed to grade the severity of focal cartilage defects along the lateral facet of the patella. Controls had knees without any abnormalities and were compared to cases with mild and severe lateral patellar OAC. Multivariable logistic regression was used to assess associations between measurements and lateral patellar OAC adjusting for body mass index. Cases were more likely to have higher Insall-Salvati ratios (OR=350; p<0.001), shorter ratios of the medial to lateral facets of the patella (OR=1.63×10-3; p<0.001), a shallower (angle closer to 180°) median eminence of the patella (OR=1.063; p=0.009), decreased trochlear cartilage overlap with the patellar cartilage (OR=0.086; p=0.023), and a less angulated lateral patellofemoral angle (OR=0.903; p=0.028), compared to controls. Cases were also more likely to have patellar tendinosis (OR=5.265; p=0.045) and oedema in the superolateral aspect of Hoffa's fat pad (OR=9.872; p<0.001). Patellar and trochlear morphology and patellar alignment are associated with lateral patellofemoral compartment OAC in young adults.

Objective Quantification of Trochlea Dysplasia: Assessment of Morphology Difference Between Control and Chronic Patellofemoral Instability Patients

Aims and Objectives:Trochlear dysplasia is an important risk factor associated with patellofemoral instability, but it remains difficult to classify with consistency. Currently there is no objective way to quantify the dysplasia. The purpose of this study to define and quantify objectively the trochlea morphology by volume and length via computed tomography (CT). Hypothesis: A significant difference in trochlea groove volume and length is present within a cohort of patients with recurrent patellofemoral instability if compared to a control cohort of similar patients.Materials and Methods:One-hundred control patients (136 knees) were retrospectively reviewed and compared to 36 consecutive patients (72 knees) who were treated surgically for recurrent patella instability and known trochlea dysplasia based on a lateral x-ray. Trochlea morphology was analyzed from a pre-operative CT and data presented as trochlear sulcus volume trochlea length. To determine where along the trochlea length dysplasia is most variable, the trochlea length was radiographically divided into thirds, volume was quantified along that section and compared to control trochlea.Results:A significant difference in trochlea morphology exists between cohorts, volume (1.98 vs 3.77 cm3) and length (31.97 vs 34.66 mm). However, there appears to be a gender based difference in trochlea morphology. The trochlea volumetric analysis between the female cohorts (L: 2.02 cm3 vs. 2.94 cm3, R: 1.95 cm3 vs. 2.93 cm3) demonstrated significant less volume in instability patients (p<0.001). The proximal 30% of trochlea contributed the majority of dysplasia difference determined by comparing mean trochlea volume, 95% of the difference. This difference decreased in distal sections, 53% and 32% respectively. The total trochlea length did not appear to be significant (L: p=0.858, R: p=0.913). It appears dysplasia alone may not directly lead to symptoms demonstrated by trochlea volumetric comparisons within symptomatic recurrent patella instability and contralateral asymptomatic patella (p=0.274).Conclusion:The authors believe this reproducible technique can be used to quantify the trochlea morphology into measurements to be used describing the severity of the dysplasia. The data confirms that symptomatic trochlea dysplasia is a “proximal” process affecting early knee flexion contact between patella and trochlea.

Three-dimensional analysis of talar trochlea morphology: Implications for subject-specific kinematics of the talocrural joint.

Three-dimensional (3D) behavior of the talocrural joint is primarily determined by the articular surface morphology of the talar trochlea and tibiofibular mortise. However, morphological features of the anterior and posterior regions of the talar trochlea remain unclear. The objectives of this study were to evaluate anterior and posterior radii of the medial and lateral talar trochlea and to estimate subject-specific kinematics of the talocrural joint. Fifty dry tali were scanned using computed tomography to create 3D bone models. Radii of curvature of the anterior and posterior region at both the medial and lateral trochlea were calculated. Orientations of the dorsiflexion and plantarflexion axis passing through the centers of the circles fitted to the anterior region of the medial and lateral trochlea and through the centers of the circles fitted to the posterior region of the medial and lateral trochlea were evaluated, respectively. The anterior radius of the medial trochlea was significantly smaller than that of the lateral trochlea by a mean of 7.8 mm (P < 0.001). The posterior radius of the medial trochlea was larger than that of lateral trochlea in 30 samples (60%) and vice versa in 20 samples (40%). Unilateral asymmetric shape of anterior trochlea would induce external rotation of the talus during ankle dorsiflexion, whereas bilateral asymmetric shape of posterior trochlea would induce opposite axial rotations among subjects during ankle plantarflexion, which would help the physical therapists to restore talocrural joint motions to ideal state for patients with ankle injuries. Clin. Anat. 29:1066-1074, 2016. © 2016 Wiley Periodicals, Inc.

Quantification Of Trochlea Dysplasia Via Computed Tomography: Assessment Of Morphology Difference Between Control And Chronic Patellofemoral Instability Patients

Objectives:Trochlear dysplasia is an important risk factor for the development of recurrent patella instability. Owing to its complex 3-Dimensional morphology, the need for a true lateral radiograph, and poor inter-observer reliability, the Dejour classification system of dysplasia may not be the most optimal measure for quantification. The purpose of this study is to report a novel technique to define and quantify the trochlea volume and length using an axial computed tomography. This technique was applied to a series of patients surgically treated for recurrent patellofemoral instability and the measurements compared to a control group.Methods:From 2007 to 2013, 99 control patients (136 knees) were identified from trauma CT scans obtained during admission at our Level I trauma hospital. Patients older than 35y/o or with fractures in the distal femur were excluded. Axial cuts at 1.25 mm were used to measure trochlea volume; defined to be from the physeal scar to the final axial image in which the sulcus could be visualized (Figure 1). Trochlear groove distance was measured from a midline sagittal reformatted image perpendicular to the posterior margin of the femoral condyles. The inter-observer reliability was assessed with independent measurements from attending orthopedist, MSK radiologist and two senior residents. Dysplasia patient cohort was a series of 35 patients (70knees) who were surgically treated for recurrent instability, by AAS or CME, from 2007-2013 and a diagnosis of dysplasia based on lateral knee radiograph. CT tracking studies are obtained from bilateral knees as a normal part of our pre-operative assessment. Institutional IRB approval was obtained for data retrieval.Results:Control cohort average age 25 +/- 4 years, 68 M:31F, without documented history of patella instability on chart review. Dysplastic cohort average age 24 +/- 5 years, 2 M:33F, all 35 patients had bilateral knees scanned. Statistically significant differences were noted in comparing the trochlea volume (3.75 +/- 0.97 cm3 vs. 2.0+/- 0.56 cm3) and the trochlea length (34.8 +/- 4.9 mm vs. 31.7 +/- 4.2 mm) between control and dysplastic cohorts respectively. Comparing female only patients demonstrated difference in trochlea volume (2.89 +/- 0.57 cm3 vs. 2.0+/- 0.36 cm3), but not trochlea length (31.7 +/- 2.5 mm vs. 31.7 +/- 2.7 mm). No difference in trochlea volume or length b/w symptomatic knee to asymptomatic contralateral knees in patients with recurrent instability (2.31 cm3 vs. 2.24 cm3) and (30.0 mm vs. 30.5 mm). Inter-observer reliability was assess measuring trochlea volume: ICC for Right Trochlea: 0.98, ICC Left Trochlea: 0.97.Conclusion:This novel technique clearly defines and quantifies the trochlea morphology into volume and length values with high ICC values. Applying this technique demonstrates a significant difference in both trochlea volume and length between a control group and patients treated for recurrent patellofemoral instability.

Chronische patellofemorale Instabilität

Chronic patellofemoral instability may lead to pain and early osteoarthrosis. Recurrent dislocations of the patella, lateral subluxation and chronic dislocation are summarized under this generic term. There are five different factors which may be responsible of the development of chronic patellofemoral instability: 1) elongation of the medial patellofemoral ligament (MPFL), 2) patella alta, 3) increased distance between tibial tuberosity and trochlea groove (TTTG) distance, 4) trochlea dysplasia and 5) torsional malalignment. To rule out these factors clinical examination, radiological diagnostics (luxation, subluxation in the Defilée view, trochlea morphology, patella alta) and magnetic resonance imaging (MRI) of TTTG distance and trochlea morphology are crucial. The indications of operative treatment are chronic pain with subluxation, chronic dislocation and recurrent dislocation. Currently the former frequently and universally used lateral release is only indicated in cases of subluxation and positive tilt. Biomechanical studies have shown that a lateral release will otherwise increase patellofemoral instability. The choice of the surgical technique depends on the factors underlying patellofemoral instability, the conditions of growth plate and cartilage damage. Among the different surgical options proximal and distal realignment procedures are differentiated. In cases of MPFL elongation and mild passive instability a medial reefing might be successful. In cases of MPFL elongation, high passive instability up to 30° of flexion (with or without trochlear dysplasia) MPFL reconstruction may be the treatment of choice. A trochleoplasty is rarely indicated. This treatment may be considered in cases of high grade trochlea dysplasia and passive instability at more than 30° of flexion. If the TTTG distance is increased (>20 mm) or in cases of patella alta distal realignment with tibial tubercle transfer should be considered. This operation might also be useful in the presence of lateral cartilage damage as an anteromedialization of the patella.