scholarly journals THE RELATIONSHIP BETWEEN PATELLAR MORPHOLOGY AND LATERAL PATELLAR INSTABILITY

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0025
Author(s):  
SM. Andelman ◽  
J. Hedgecock ◽  
M. Solomito ◽  
R. Kostyun ◽  
JL. Pace
Keyword(s):  
Patellar Instability ◽  
Trochlear Dysplasia ◽  
Cruciate Ligament ◽  
Tibial Tubercle ◽  
Control Group ◽  
Data Points ◽  
The Relationship ◽  
Patellar Morphology ◽  
Lateral Facet ◽  
And Cartilage

Background: Lateral patellar instability (LPI) is a substantial cause of morbidity in the pediatric population. Previously identified risk factors for LPI include trochlear dysplasia, a lateralized tibial tubercle, genu valgum, femoral anteversion, and external tibial torsion. Less is known regarding the relationship between patellar morphology and LPI. Purpose: The goal of this study is to determine whether there exists a relationship between patellar morphology and LPI. Methods: Magnetic resonance imaging (MRI) evaluation was performed for patients under 18 years of age with LPI and compared to a control group of MRIs of patients with anterior cruciate ligament (ACL) rupture. Using T2 axial MRI images, the lateral and medial facet angle of both the bone and cartilage of the patella was measured at three locations: the most proximal and distal aspects of the patella where the cartilage of the facets could be identified and the widest point of the patella. The width of the patella at each point was also recorded, resulting in 15 total data points per subject (5 at each of the three locations on the patella). Results were analyzed and compared between the instability group and the control group to determine any relationship between facet angle and LPI. Results: 196 MRIs were reviewed, 97 in the instability group and 96 in the control group. The LPI group was noted to have a less steep angle at the proximal medial patellar facet of both the bone (LPI 27.2° ± 9.3° ; control 32.7° ± 8.8°, p < 0.001) and cartilage (LPI 26.5° ± 8.8°, control 32.7° ± 8.4°, p < 0.001) as well as a less steep angle of the cartilage at the distal lateral facet (LPI 23.4° ± 7.2°, control 25.6° ± 6.6°, p = 0.033). No other differences were noted for the remaining 12 data points. Conclusion: The are very few differences in patellar morphology between patients with and without LPI. Patients were LPI have a less steep angle of the bone of the proximal medial facet, the cartilage of the proximal medial facet, and the cartilage of the distal lateral facet when compared to a control group. [Figure: see text]

Effect of Medialization of the Trochlear Groove and Lateralization of the Tibial Tubercle on TT-TG Distance: A Cross-sectional Study of Dysplastic and Nondysplastic Knees

2021 ◽  
pp. 036354652098781
Author(s):  
Mathias Paiva ◽  
Lars Blønd ◽  
Per Hölmich ◽  
Kristoffer Weisskirchner Barfod
Keyword(s):  
Trochlear Dysplasia ◽  
Cross Sectional Study ◽  
Magnetic Resonance Images ◽  
Tibial Tubercle ◽  
Control Group ◽  
Trochlear Groove ◽  
Sectional Study ◽  
Cross Sectional ◽  
Mean Values ◽  
The Mean

Background: Tibial tubercle–trochlear groove (TT-TG) distance is often used as a measure of lateralization of the TT and is important for surgical planning. Purpose: To investigate if increased TT-TG distance measured on axial magnetic resonance images is due to lateralization of the TT or medialization of the TG. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 84 knees (28 normal [NK], 28 with trochlear dysplasia [TD], and 28 with patellar dislocation without TD [PD]) were examined. The medial border of the posterior cruciate ligament (PCL) was chosen as the central anatomic landmark. The distance from the TT to PCL (TT-PCL) was measured to examine the lateralization of the TT. The distance from the TG to the PCL (TG-PCL) was measured to examine the medialization of the TG. Between-group differences were investigated by use of 1-way analysis of variance. Results: The mean values for TT-TG distance were 8.7 ± 3.6 mm for NK, 12.1 ± 6.0 mm for PD, and 16.7 ± 4.3 mm in the TD group ( P < .01). The mean values for TT-PCL distance were 18.5 ± 3.6 mm for NK, 18.5 ± 4.5 mm for PD, and 21.2 ± 4.2 mm in the TD group ( P = .03). The mean values for TG-PCL distance were 9.6 ± 3.0 mm for NK, 7.1 ± 3.4 mm for PD, and 5.1 ± 3.3 mm in the dysplastic group ( P < .01). Conclusion: The present results indicate that increased TT-TG distance is due to medialization of the TG and not lateralization of the TT. Knees with TD had increased TT-TG distance compared with the knees of the control group and the knees with PD. The TT-PCL distance did not differ significantly between groups, whereas the TG-PCL distance declined with increased TT-TG.

scholarly journals Comparing the Tibial Tuberosity–Trochlear Groove Distance Between CT and MRI in Skeletally Immature Patients With and Without Patellar Instability

2021 ◽  
Vol 9 (1) ◽  
pp. 232596712097366
Author(s):  
Zhen-Zhen Dai ◽  
Lin Sha ◽  
Zi-Ming Zhang ◽  
Zhen-Peng Liang ◽  
Hao Li ◽  
...  
Keyword(s):  
Patellar Instability ◽  
Intraclass Correlation ◽  
Mean Difference ◽  
Tibial Tubercle ◽  
Control Group ◽  
Trochlear Groove ◽  
Skeletally Immature ◽  
Bony Landmarks ◽  
The Difference ◽  
Ct And Mri

Background: The tibial tubercle–trochlear groove (TT-TG) distance was originally described for computed tomography (CT), but it has been measured on magnetic resonance imaging (MRI) in patients with patellar instability (PI). Whether the TT-TG measured on CT versus MRI can be considered equivalent in skeletally immature children remains unclear. Purpose: To investigate in skeletally immature patients (1) the effects of CT versus MRI imaging modality and cartilage versus bony landmarks on consistency of TT-TG measurement, (2) the difference between CT and MRI measurements of the TT-TG, and (3) the difference in TT-TG between patients with and without PI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We retrospectively identified 24 skeletally immature patients with PI and 24 patients with other knee disorders or injury but without PI. The bony and cartilaginous TT-TG distances on CT and MRI were measured by 2 researchers, and related clinical data were collected. The interrater, interperiod (bony vs cartilaginous), and intermethod (CT vs MRI) reliabilities of TT-TG measurement were assessed with intraclass correlation coefficients. Results: The 48 study patients (19 boys, 29 girls) had a mean age of 11.3 years (range, 7-14 years). TT-TG measurements had excellent interrater reliability and good or excellent interperiod reliability but fair or poor intermethod reliability. TT-TG distance was greater on CT versus MRI (mean difference, 4.07 mm; 95% CI, 2.6-5.5 mm), and cartilaginous distance was greater than bony distance (mean difference, 2.3 mm; 95% CI, 0.79-3.8 mm). The TT-TG measured on CT was found to increase with the femoral width. Patients in the PI group had increased TT-TG distance compared with those in the control group, regardless of landmarks or modality used ( P > .05 for all). Conclusion: For skeletally immature patients, the TT-TG distance could be evaluated on MRI, regardless of whether cartilage or bony landmarks were used. Its value could not be interchanged with CT according to our results; however, further research on this topic is needed.

scholarly journals Early patellofemoral articular cartilage degeneration in a rat model of patellar instability is associated with activation of the NF-κB signaling pathway

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wei Lin ◽  
Huijun Kang ◽  
Yike Dai ◽  
Yingzhen Niu ◽  
Guangmin Yang ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Signaling Pathway ◽  
Subchondral Bone ◽  
Patellofemoral Joint ◽  
Patellar Instability ◽  
Cartilage Degeneration ◽  
Control Group ◽  
And Control ◽  
Articular Cartilage Degeneration ◽  
And Cartilage

Abstract Background Patellar instability (PI) often increases the possibility of lateral patellar dislocation and early osteoarthritis. The molecular mechanism of early articular cartilage degeneration during patellofemoral osteoarthritis (PFOA) still requires further investigation. However, it is known that the NF-κB signaling pathway plays an important role in articular cartilage degeneration. The aim of this study was to investigate the relationship between the NF-κB signaling pathway and patellofemoral joint cartilage degeneration. Methods We established a rat model of PI-induced PFOA. Female 4-week-old Sprague-Dawley rats (n = 120) were randomly divided into two groups: the PI (n = 60) and control group (n = 60). The distal femurs of the PI and control group were isolated and compared 4, 8, and 12 weeks after surgery. The morphological structure of the trochlear cartilage and subchondral bone were evaluated by micro-computed tomography and histology. The expression of NF-κB, matrix metalloproteinase (MMP)-13, collagen X, and TNF-ɑ were evaluated by immunohistochemistry and quantitative polymerase chain reaction. Results In the PI group, subchondral bone loss and cartilage degeneration were found 4 weeks after surgery. Compared with the control group, the protein and mRNA expression of NF-κB and TNF-ɑ were significantly increased 4, 8, and 12 weeks after surgery in the PI group. In addition, the markers of cartilage degeneration MMP-13 and collagen X were more highly expressed in the PI group compared with the control group at different time points after surgery. Conclusions This study has demonstrated that early patellofemoral joint cartilage degeneration can be caused by PI in growing rats, accompanied by significant subchondral bone loss and cartilage degeneration. In addition, the degeneration of articular cartilage may be associated with the activation of the NF-κB signaling pathway and can deteriorate with time as a result of PI.

Clinical validation of the Oswestry-Bristol Classification as part of a decision algorithm for trochlear dysplasia surgery

2021 ◽  
Vol 103-B (10) ◽  
pp. 1586-1594
Author(s):  
Nikhil Sharma ◽  
Nader Rehmatullah ◽  
Jan Herman Kuiper ◽  
Peter Gallacher ◽  
Andrew J. Barnett
Keyword(s):  
Treatment Group ◽  
Complication Rate ◽  
Patellar Instability ◽  
Assessment Tool ◽  
Trochlear Dysplasia ◽  
International Knee Documentation Committee ◽  
Tibial Tubercle ◽  
Decision Algorithm ◽  
Additional Surgery ◽  
Five Dimension

Aims The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective. Methods The OBC and the patellotrochlear index were used as part of the Oswestry Patellotrochlear Algorithm (OPTA) to guide the surgical treatment of patients with patellar instability. Patients were assigned to one of four treatment groups: medial patellofemoral ligament reconstruction (MPFLr); MPFLr + tibial tubercle distalization (TTD); trochleoplasty; or trochleoplasty + TTD. A prospective analysis of a longitudinal patellofemoral database was performed. Between 2012 and 2018, 202 patients (233 knees) with a mean age of 24.2 years (SD 8.1), with recurrent patellar instability were treated by two fellowship-trained consultant sports/knee surgeons at The Robert Jones and Agnes Hunt Orthopaedic Hospital. Clinical efficacy of each treatment group was assessed by Kujala, International Knee Documentation Committee (IKDC), and EuroQol five-dimension questionnaire (EQ-5D) scores at baseline, and up to 60 months postoperatively. Their safety was assessed by complication rate and requirement for further surgery. The pattern of clinical outcome over time was analyzed using mixed regression modelling. Results In all, 135 knees (mean age 24.9 years (SD 9.4)) were treated using a MPFLr. Ten knees (7.4%) required additional surgery. A total of 50 knees (mean age 24.4 years (SD 6.3)) were treated using MPFLr + TTD. Ten (20%) required additional surgery. A total of 20 knees (mean age 19.5 years (SD 3.0)) were treated using trochleoplasty + TTD. Three patients (15%) required additional surgery. In each treatment group, there was a significant improvement in Kujala, IKDC, and EQ-5D at one year postoperatively (p < 0.001) with a recognized level of overall complication rate. Conclusion The OBC is a valid assessment tool to grade patients with trochlear dysplasia and, when used as part of the OPTA, helps to determine treatments that are safe and effective. This fulfils the requirements for its application in mainstream clinical practice. Cite this article: Bone Joint J 2021;103-B(10):1586–1594.

scholarly journals A Knee Size-Independent Parameter for Malalignment of the Distal Patellofemoral Joint in Children

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Ferdinand Wagner ◽  
Günther Maderbacher ◽  
Jan Matussek ◽  
Boris M. Holzapfel ◽  
Birgit Kammer ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Patellofemoral Joint ◽  
Cruciate Ligament ◽  
Independent Parameter ◽  
Common Finding ◽  
Tibial Tubercle ◽  
Control Group ◽  
Study Cohort ◽  
Tendon Insertion ◽  
Knee Size

Introduction. Patellar instability (PI) is a common finding in children. Current parameters describing patellofemoral joint alignment do not account for knee size. Additionally, most parameters utilize joint-crossing tibiofemoral landmarks and are prone to errors. The aim of the present study was to develop a knee size-independent parameter that is suitable for pediatric or small knees and determines the malpositioning of the distal patellar tendon insertion solely utilizing tibial landmarks. Methods. Sixty-one pediatric knees were included in the study. The tibial tubercle posterior cruciate ligament distance (TTPCL) was measured via magnetic resonance imaging (MRI). The tibial head diameter (THD) was utilized as a parameter for knee size. An index was calculated for the TTPCL and THD (TTPCL/THD). One-hundred adult knees were analyzed to correlate the data with a normalized cohort. Results. The THD was significantly lower in healthy females than in males (69.3 mm ± 0.8 mm vs. 79.1 mm ± 0.7 mm; p<0.001) and therefore was chosen to serve as a knee size parameter. However, no gender differences were found for the TTPCL/THD index in the healthy adult study cohort. The TTPCL/THD was significantly higher in adult PI patients than in the control group (0.301 ± 0.007 vs. 0.270 ± 0.007; p=0.005). This finding was repeated in the PI group when the pediatric cohort was analyzed (0.316 ± 0.008 vs. 0.288 ± 0.010; p=0.033). Conclusion. The TTPCL/THD index represents a novel knee size-independent measure describing malpositioning of the distal patellar tendon insertion determined solely by tibial landmarks.

scholarly journals The Role of Abnormal Tibiofemoral Rotation in Pediatric and Adolescent Patellar Instability

2018 ◽  
Vol 6 (7_suppl4) ◽  
pp. 2325967118S0007
Author(s):  
David Bernholt ◽  
Joseph D. Lamplot ◽  
Eric Eutsler ◽  
Jeffrey J. Nepple
Keyword(s):  
Patellar Instability ◽  
External Rotation ◽  
Interobserver Reliability ◽  
Cruciate Ligament ◽  
Tibial Tubercle ◽  
Case Group ◽  
Trochlear Groove ◽  
Retrospective Case ◽  
Femoral Trochlea ◽  
Tibiofemoral Rotation

Objectives: Abnormal patellofemoral tracking has been implicated in patellar instability and can be influenced by the bony anatomy and alignment of the femoral trochlea, patella, and tibial tubercle. Tibiofemoral joint rotation has been recently suggested to play a role in patellofemoral kinematics but there has been little investigation of its contribution to patellar instability, including in pediatric and adolescent patients. Methods: A retrospective case-control design was utilized. 30 patients aged 9-18 with a prior patellar dislocation and an MRI of the involved knee were included. Cases were matched for age and gender with controls without patellar instability. Patients with ACL tears, tibial eminence or tubercle fractures, or prior surgery in the involved extremity were excluded. There was no difference in gender, age, height, but BMI was higher in the case group. MRI images taken with knee in extension were analyzed. Tibial tubercle-trochlear groove (TT-TG), tibial tubercle-posterior cruciate ligament (TT-PCL), and tibiofemoral rotation were measured. All measurements were performed by a single reader with excellent intra and interobserver reliability for tibiofemoral rotation (ICC-intra > .954 and ICC-inter > .905) demonstrated in a subset of patients. Results: The TT-TG was increased in patients with patellar instability at 16.3 mm compared to 10.9 mm in controls (p <.001) as was also the TT-PCL at 19.4 mm cases versus 17.6 mm (p=0.02). Tibiofemoral rotation was increased in patients with patellar instability with a mean 6.9° of tibial external rotation compared to 0.8° of tibial internal rotation in controls (p < .001). Overall, 30/41 (75.6%) of patients with patellar instability had tibiofemoral rotation >5° external rotation versus only 3/41 controls (7.3%). There was a strong correlation between TT-TG and tibiofemoral rotation (PCC = 0.776) and a moderate correlation between TT-TG and TT-PCL (PCC = .661). There was only a weak correlation between tibiofemoral rotation and TT-PCL. Conclusion: Increased tibiofemoral rotation is present in patients with patellar instability and may play a role in the pathophysiology of patellar instability. Increased tibiofemoral rotation can lead to an increased TT-TG even when TT-PCL is normal.

scholarly journals INCREASED TIBIOFEMORAL ROTATION WITH INCREASING SEVERITY OF PATELLAR INSTABILITY

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0023
Author(s):  
Kenneth M. Lin ◽  
Evan W. James ◽  
Lindsay Schlichte ◽  
Grace Wang ◽  
Daniel Green
Keyword(s):  
Patellar Instability ◽  
External Rotation ◽  
Intraclass Correlation ◽  
Mpfl Reconstruction ◽  
Tibial Tubercle ◽  
Tibial Rotation ◽  
Trochlear Groove ◽  
Clinical Effects ◽  
Tibiofemoral Rotation ◽  
The Relationship

Background: Tibiofemoral rotation (TFR), specifically external tibial rotation, has been recently identified as a potential contributing factor to patellar instability. However, no previous studies have explored the clinical effects of differing degrees of TFR in relation to patellar instability. Purpose and Hypothesis: The purpose of this study is to investigate the relationship between severity of instability with degree of TFR. Our hypothesis is that fixed or obligatory dislocators (FOD) are more likely to have increased external TFR (tibial external rotation compared to femur) than standard patellar instability (SPI) patients requiring medial patellofemoral ligament (MPFL) reconstruction, who will have similar or slightly increased external TFR compared to normal controls. Methods: A retrospective study was performed with patients from 3 cohorts from April 2009 to February 2019: FOD, SPI, and controls with normal magnetic resonance imaging (MRI) of the knee. All FOD patients from the study time frame were analyzed, while controls and SPI patients were randomly selected. Patients were included for age under 18 years and diagnosis corresponding to one of the three cohorts, and excluded for outside institution MRI, and previous MPFL reconstruction or tibial tubercle osteotomy. TFR was measured on preoperative axial MRI using the posterior femoral and tibial condylar lines (Figure 1). Tibial tubercle to trochlear groove distance (TT-TG) was measured. Intraclass correlation coefficient (ICC) was calculated among 3 measurers. Statistical analysis using ANOVA and t-test was performed with significance set at α=0.05. Results: A total of 57 patients were included, 19 in each cohort. Average age was 13.2 years (range 10-17 years), with 31 females (54%). ICC for TT-TG and TFR were 0.90 and 0.72, respectively. TT-TG differed between the controls and SPI patients (both P<0.001), and controls and FOD patients (P<0.001), but not between SPI and FOD patients (P=0.12). TFR differed among the three groups: 8.4° (SD 16.7°) external TFR in FOD, 1.6° (SD 5.4°) external TFR in SPI, and 2.5° (SD 5.8°) internal TFR in controls (P=0.0089). FOD patients had significantly greater external tibial rotation than the SPI group (P=0.047). Conclusions: The degree of TFR is correlated with severity of patellar instability, with greater external tibial rotation seen in FOD than SPI patients, while TT-TG was not different. Further information on the relationship of TFR and patellar instability will not only improve understanding of pathogenesis and prognosis, but may also direct surgical treatment strategies in refractory or severe cases. [Figure: see text][Figure: see text]

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