The Relationship Between Tibial Tuberosity–Trochlear Groove Distance and Abnormal Patellar Tracking in Patients With Unilateral Patellar Instability

Author(s):  
Ariel A. Williams ◽  
John J. Elias ◽  
Miho J. Tanaka ◽  
Gaurav K. Thawait ◽  
Shadpour Demehri ◽  
...  
2019 ◽  
Vol 7 (6_suppl4) ◽  
pp. 2325967119S0022
Author(s):  
Peter Balcarek ◽  
Dennis Vogel

Aims and Objectives: To analyze parameters of limb malalignment and patellar tracking in patients with torsional malalignment syndrome presenting with clinical symptoms of either patellofemoral pain or patellar instability. Materials and Methods: Between April 2015 and July 2017, 428 patients were treated for lateral patellar instability (LPD), and 333 patients were treated for patellofemoral pain syndrome (PFPS). Sixty-two patients (14.5%) with patellar instability (LPD group) and 29 patients (8.7%) with patellofemoral pain (PFPS group) had additional torsional malalignment and were included in this study. All patients underwent magnetic resonance imaging assessment of torsional alignment and patellar tracking, including femoral antetorsion, tibial torsion, knee rotation, tibial tuberosity-trochlear groove distance, tibial tuberosity-posterior cruciate ligament distance, Dejour’s classification of trochlear dysplasia, lateral trochlear inclination angle, and patellar height Results: Groups differed significantly in terms of trochlear dysplasia (p<0.001), lateral trochlear inclination angle (p<0.001) and tibial tuberosity-trochlear groove distance (p=0.0167) but did not differ in terms of femoral torsion (LPD group 20.02° +/- 8.8°; PFPS group 20.03° +/- 7.91°; p=0.8545), tibial torsion (LPD group 39.53° +/- 9.23°; PFPS group 41.24° +/- 7.28°; p=0.3616), and knee rotation (LPD group 10.42° +/- 5.16°; PFPS group 8.48° +/- 7.81°; p=0.0163). Only measures of coronal alignment were positively correlated. This was also true for the tibial tuberosity-trochlear groove distance and knee rotation but not for any other parameters of torsional limb alignment. Trochlear dysplasia (type B-D) was identified as the only significant predictor of patellar instability. Conclusion: Torsional malalignment syndrome, represented in this study by two clinical entities - PFPS and LPD - is not characterized by a typical constellation of different malalignment parameters. Between groups, parameters differed significantly only in terms of trochlear dysplasia and the tibial tuberosity-trochlear groove distance, with trochlear dysplasia (type B-D), but not torsion, identified as predictor of lateral patellar instability.


2012 ◽  
Vol 20 (12) ◽  
pp. 2399-2404 ◽  
Author(s):  
A. D. Cooney ◽  
Z. Kazi ◽  
N. Caplan ◽  
M. Newby ◽  
A. St Clair Gibson ◽  
...  

2021 ◽  
pp. 036354652110377
Author(s):  
Jong-Min Kim ◽  
Jae-Ang Sim ◽  
HongYeol Yang ◽  
Young-Mo Kim ◽  
Joon-Ho Wang ◽  
...  

Background: No clear guidelines or widespread consensus has defined a threshold value of tibial tuberosity–trochlear groove (TT-TG) distance for choosing the appropriate surgical procedures when additional tibial tuberosity osteotomy (TTO) should be added to augment medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar instability. Purpose: To compare the clinical outcomes between MPFL reconstruction and MPFL reconstruction with TTO for patients who have patellar instability with a TT-TG distance of 15 to 25 mm. Study Design: Cohort study; Level of evidence, 3. Methods: We retrospectively analyzed 81 patients who underwent surgical treatment using either MPFL reconstruction or MPFL reconstruction with TTO for recurrent patellar instability with a TT-TG distance of 15 to 25 mm; the mean follow-up was 25.2 months (range, 12.0-53.0 months). The patients were divided into 2 groups: isolated MPFL reconstruction (iMPFL group; n = 36) performed by 2 surgeons and MPFL reconstruction with TTO (TTO group; n = 45) performed by another 2 surgeons. Clinical outcomes were assessed using the Kujala score, Knee injury and Osteoarthritis Outcome Score, and Tegner activity score. Radiological parameters, including patellar height, TT-TG distance, patellar tilt, and congruence angle were compared between the 2 groups. Functional failure based on clinical apprehension sign, repeat subluxation or dislocation, and subjective instability and complications was assessed at the final follow-up. We also compared clinical outcomes based on subgroups of preoperative TT-TG distance (15 mm ≤ TT-TG ≤ 20 mm vs 20 mm < TT-TG ≤ 25 mm). Results: All of the clinical outcome parameters significantly improved in both groups at the final follow-up ( P < .001), with no significant differences between groups. The radiological parameters also showed no significant differences between the 2 groups. The incidence of functional failure was similar between the 2 groups (3 failures in the TTO group and 2 failures in the iMPFL group; P = .42). In the TTO group, 1 patient experienced a repeat dislocation postoperatively and 2 patients had subjective instability; in the iMPFL group, 2 patients had subjective instability. The prevalence of complications did not differ between the 2 groups ( P = .410). In the subgroup analysis based on TT-TG distance, we did not note any differences in clinical outcomes between iMPFL and TTO groups in subgroups of 15 mm ≤ TT-TG ≤ 20 mm and 20 mm < TT-TG ≤ 25 mm. Conclusion: MPFL reconstruction with and without TTO provided similar, satisfactory clinical outcomes and low redislocation rates for patients who had patellar instability with a TT-TG distance of 15 to 25 mm, without statistical difference. Thus, our findings suggest that iMPFL reconstruction is a safe and reliable treatment for patients with recurrent patellar dislocation with a TT-TG distance of 15 to 25 mm, without the disadvantages derived from TTO.


SICOT-J ◽  
2019 ◽  
Vol 5 ◽  
pp. 25
Author(s):  
Sourabh Kulkarni ◽  
Amith P. Shetty ◽  
Karan K. Alva ◽  
Saurabh Talekar ◽  
Vijay D. Shetty

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0023
Author(s):  
Kenneth M. Lin ◽  
Evan W. James ◽  
Lindsay Schlichte ◽  
Grace Wang ◽  
Daniel Green

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]


2020 ◽  
Vol 8 (7) ◽  
pp. 232596712093876
Author(s):  
J. Lee Pace ◽  
Chris Cheng ◽  
Sheeba M. Joseph ◽  
Matthew J. Solomito

Background: Trochlear dysplasia (TD) is an important anatomic risk factor for patellar instability (PI). Several imaging-based risk factors for PI have been established, but it is unclear what effect TD has on these measurements, and the Dejour method of categorizing TD has been shown to be unreliable. The lateral trochlear inclination (LTI) is a quantifiable measurement of proximal trochlear morphology. Recently, a modified technique for measuring LTI referencing the posterior condylar angle has demonstrated near-perfect reliability and may serve as a new standard for quantifying TD. Purpose/Hypothesis: The purpose of this study was to evaluate how TD, expressed in terms of LTI, affects historically used measures of PI, including the sulcus angle (SA), tibial tuberosity to trochlear groove (TT-TG) distance, lateral patellar inclination (LPI), and Caton-Deschamps (CD) ratio. We hypothesized that lower LTI (ie, more dysplastic trochlea) will correlate with higher SA and TT-TG distances, increased patellar tilt, and more patella alta. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients aged 9 to 18 years treated for PI between January 2014 and August 2017 were queried. On magnetic resonance imaging (MRI), LTI, SA, LPI, and the TT-TG measured at the most proximal (pTT-TG) and distal (dTT-TG) aspects of the fully formed trochlear groove were measured on axial images. CD ratio was measured using sagittal MRI as well as lateral radiographs. All measurements were performed by 2 independent observers. Patients were included if there was a diagnosis of PI that was confirmed with a chart review and if there were appropriate imaging studies to analyze. Results: A total of 65 patients met inclusion criteria for this study. Average pTT-TG distance (15.7 ± 4.5 mm) was not significantly different from dTT-TG distance (15.7 ± 4.2 mm) ( P = .94). LTI had a weak but significant inverse correlation with pTT-TG ( r = –0.40; β = –0.15 mm; P < .001) and SA ( r = –0.43; β = –0.478°; P < .001). There was a moderate and significant inverse correlation of LTI with dTT-TG ( r = –0.593; β = –0.21 mm; P < .001) and with LPI ( r = –0.69; β = –0.54°; P < .001). There was a weak but significant correlation between LTI and the MRI-based CD ratio ( r = 0.279; β = 0.149; P = .005). Radiograph-based CD ratio did not show a significant correlation with LTI ( r = –0.189; P = .135). Conclusion: Smaller (ie, more dysplastic) LTI values correlated significantly with larger TT-TG, SA, LPI, and MRI-based CD ratio measurements. The relationship between SA and LTI is intuitive, but the relationship between LTI and the other analyzed variables suggests that they are dependent variables to TD and may not be consistent independent risk factors for PI. Together, these suggest that TD alters the radiographic interpretation of TT-TG and patellar tilt. The correlation between TD and patellar height is unclear and warrants further investigation.


2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0048
Author(s):  
Evan James ◽  
Alexandra Aitchison ◽  
Lindsay Schlichte ◽  
Grace Wang ◽  
Daniel Green ◽  
...  

Objectives: 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. 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.


2017 ◽  
Vol 45 (8) ◽  
pp. 1856-1863 ◽  
Author(s):  
Victor R. Carlson ◽  
Frances T. Sheehan ◽  
Aricia Shen ◽  
Lawrence Yao ◽  
Jennifer N. Jackson ◽  
...  

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