scholarly journals Tibial Tubercle–Roman Arch Distance: A New Measurement of Patellar Dislocation and Indication of Tibial Tubercle Osteotomy

2020 ◽  
Vol 8 (4) ◽  
pp. 232596712091487 ◽  
Author(s):  
Zijie Xu ◽  
Hua Zhang ◽  
Binjie Fu ◽  
Sheikh Ibrahimrashid Mohamed ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Relative Position ◽  
Patellar Dislocation ◽  
Trochlear Dysplasia ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Tibial Tubercle Osteotomy ◽  
Distance Measurements ◽  
Significant Difference ◽  
Reliable Parameter ◽  
And Control

Background: The surgical indication for tibial tubercle osteotomy (TTO) has been based on a tibial tubercle–trochlear groove (TT-TG) distance of 20 mm or greater in patients with patellar dislocation. However, the measurement of this parameter is less reliable in patients with trochlear dysplasia. Hypothesis: The novel measurement of tibial tubercle–Roman arch (TT-RA) distance would be a reliable parameter for identifying the relative position of the tibial tubercle in patients with patellar dislocation, especially those with trochlear dysplasia. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 56 patients with a diagnosis of patellar dislocation and 60 volunteers (60 knee joints) without a history of lower extremity pain or injury were included in our study. The TT-RA distance, TT-TG distance, and some femoral anatomic parameters were assessed by use of computed tomography. The measurements were performed by a radiologist and an orthopaedic surgeon in a blinded and randomized fashion. The difference in each parameter between the study and control groups was analyzed through use of an unpaired t test. Receiver operating characteristic curve analysis was performed to evaluate the discriminatory capacity of the included parameters. The cutoff values of the included measurements with specificity and sensitivity were calculated. In addition, the TT-TG distance and TT-RA distance were analyzed using the Dejour classification to evaluate the intraclass correlation coefficient (ICC) of each parameter in different types of femoral trochlea. Result: A significant difference for TT-RA distance was found between the study group (23.24 ± 4.41 mm) and control group (19.15 ± 4.24 mm) ( P < .001). The TT-RA distance had an area under the curve of 0.757. At a value greater than 23.74 mm, TT-RA distance had 53.57% sensitivity and 88.33% specificity for patellar dislocation. The ICCs of TT-RA distance measurements were excellent in all Dejour classifications (>0.939), whereas the ICCs of TT-TG distance measurements were relatively lower than the ICCs of TT-RA distance measurements. According to the data from included healthy individuals, the pathological TT-RA distance threshold was 26 mm. Conclusion: Compared with TT-TG distance, the TT-RA distance is a more reliable parameter for identifying the relative position of the tibial tubercle in patients with trochlear dysplasia. For patients with a TT-RA distance greater than 26 mm, surgery should be considered to correct the malposition of the tibial tubercle.

scholarly journals Complex Patellofemoral Reconstruction for Recurrent Instability

2022 ◽  
Vol 2 (1) ◽  
pp. 263502542110353
Author(s):  
Edward R. Floyd ◽  
Nicholas I. Kennedy ◽  
Adam J. Tagliero ◽  
Gregory B. Carlson ◽  
Robert F. LaPrade
Keyword(s):  
Soft Tissue ◽  
Trochlear Dysplasia ◽  
Quadriceps Tendon ◽  
Patellar Height ◽  
Mpfl Reconstruction ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Suture Anchors ◽  
Tibial Tubercle Osteotomy ◽  
Drill Holes

Background: Patellofemoral instability is due to a combination of bony and soft tissue factors. While recurrent patellar dislocations are rare, evaluation and treatment of these conditions require addressing patellar height and lateralization of the tibial tubercle (TT), restraint to lateral patellar subluxation, and trochlear dysplasia. Other factors to consider are coronal limb-length alignment outside of the physiologic 5 to 8° of valgus, which may significantly alter the Q angle and contribute to lateral instability. Other ligaments around the patella contribute to soft-tissue restraint, including the medial and lateral patellotibial ligaments, patellomeniscal ligaments, and the medial quadriceps tendon femoral ligament. Patellar tilt is assessed with and without quadriceps contraction to further evaluate the patella’s relationship to the trochlear groove. The Caton-Deschamps Index, as well as patellar trochlear index (PTI), are used to measure patellar height for patella alta or baja. Technique Description: The technique is to surgically manage a patient in neutral mechanical alignment on standing limb radiographs, with moderate-to-severe DeJour type B trochlear dysplasia and a trochlear sulcus angle of around 145°, patella alta with a Caton-Deschamps Index of 1.6 and PTI of 0.22, a TT to trochlear groove (TT-TG) distance of 8 mm, and a deficient medial patellofemoral ligament (MPFL). The MPFL reconstruction is done first, with harvesting of the ipsilateral quadriceps tendon and maintenance of its distal attachment on the superior patellar pole. The quadriceps tendon graft is folded medially upon its distal attachment and fixed in this position with suture anchors. Tibial tubercle osteotomy is accomplished by spacing drill holes 2 mm apart, medially and laterally, on the TT and connecting the drill holes with an osteotome and reciprocating saw. A distalized location to secure the TT is selected and superficial bone is excised. A medial parapatellar arthrotomy is performed, and bur attachments are used to drill into the subchondral bone beneath the femoral articular surface to create a V-shaped flap of trochlear cartilage. An arthroscope is inserted under the trochlear flap during this process to visualize the appropriate depth. The trochlear flap is then secured with screws passed over guide pins to secure the flap to the desired location. Cannulated screws and washers are then used to secure the TT to its distalized and/or medialized position, with fluoroscopic verification of screw depth and location. The arthrotomy is then closed with the knee at 45°. The quadriceps graft is passed through a subretinacular channel and secured with suture anchors, adjacent to the adductor tubercle, to complete the MPFL reconstruction. Before closure, appropriate tracking and translation of the patella is verified. Results: Sulcus-deepening trochleoplasty, with or without MPFL reconstruction, has been reported to obtain satisfactory outcomes at 2 years, with close to 85% return to sport and 100% return to work, with improvements in International Knee Documentation Committee (IKDC) scores from 50.8 to 79.1 in some studies. MPFL reconstruction with tibial tubercle osteotomy (TTO) has yielded a 94.5% patient satisfaction rate in the literature. Discussion/Conclusion: In patients with recurrent patellar instability and DeJour types B-D trochlear dysplasia, MPFL reconstruction with TTO and sulcus-deepening trochleoplasty provides excellent subjective outcomes and restores patellar tracking with elimination of recurrent subluxation.

scholarly journals Correlations between intra and extraarticular factors measured by computed tomography in patients with recurrent patellar dislocation

2020 ◽  
Vol 3 (1) ◽  
pp. 20-28
Author(s):  
Georgian Iacobescu ◽  
Adrian Cursaru ◽  
Dan Anghelescu ◽  
Mihnea Popa ◽  
Dan Popescu
Keyword(s):  
Computed Tomography ◽  
Patellar Dislocation ◽  
Rotation Angle ◽  
Tibial Tuberosity ◽  
Tibial Tubercle ◽  
Control Group ◽  
Study Group ◽  
Trochlear Groove ◽  
Tibial Tubercle Osteotomy ◽  
Lateral Patellar Dislocation

AbstractIntroduction: Lateral patellar dislocation (LPD) is a common injury of the knee, most frequent in young patients. It has a multifactorial etiology with several underlying risk factors. In most cases, patellar dislocation occurs on the lateral side, with the rupture of the medial patellofemoral ligament (MPFL), appearing in more than 80% of the cases. The tibial tuberosity-trochlear groove (TT-TG) distance of 20 mm or more in patients with lateral patellar dislocation is a gold standard for the surgical indication of tibial tubercle osteotomy (TTO).Hypothesis: Our investigation aimed to establish whether there is a correlation between the TT-TG distance and other bony landmarks, like trochlear groove medialization, tibial tuberosity lateralization, and knee rotation angle, in the surgical algorithm for the patient with patellar dislocation.Methods: We conducted a prospective study, analyzing and comparing data from two groups, 33 patients with a diagnosis of patellar dislocation, and a control group of 30 patients, with meniscal injury, but healthy contralateral limb. Using computed tomography, we measured the TT-TG distance, femoral anteversion, tibial torsion, knee rotation angle, tuberosity lateralization, and trochlear groove medialization of all the patients in our study. The measurements were conducted by two independent orthopedic surgeons in a randomized manner. Using an unpaired t test, we compared and analyzed each parameters value from the study and the control group.Results: Comparing the two groups, we observed a significant difference for TT-TG distance, knee rotation angle and tibial tuberosity lateralization with higher values in the study group compared to the control group (CI 95% 6.44-9.72, CI 95% 8.64-10.39, CI 95% 3.77-5.46, respectively), with a p value < 0.0001 in all cases. Also, the TT-TG distance positively correlated with knee rotation angle (r=.97, p=0.01) and tibial tuberosity lateralization (r=.86, p=0.0001) in the study group.Conclusions: The TT-TG distance measurement usually defines the lateralization of the tibial tuberosity; yet, in some cases, it can be caused by the trochlear groove medialization, or high rotation between the femur and tibia. Our study revealed that knee rotation and tuberosity lateralization were factors implicated in patellar dislocation and they should be taken into account when making the decision of tibial tubercle osteotomy.

Bisect offset ratio and cartilaginous sulcus angle are good combined predictors of recurrent patellar dislocation in children and adolescents

2021 ◽  
pp. jisakos-2020-000461
Author(s):  
Sheanna Maine ◽  
Christina Ngo-Nguyen ◽  
Martina Barzan ◽  
Chris Stockton ◽  
Luca Modenese ◽  
...  
Keyword(s):  
Patellar Dislocation ◽  
Trochlear Dysplasia ◽  
Pediatric Population ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Recurrent Patellar Dislocation ◽  
Patellar Tilt ◽  
Level Of Evidence ◽  
Femoral Torsion ◽  
Sulcus Angle

ObjectivesRecurrent patellar dislocation (RPD) is found most commonly in the juvenile population. While risk factors have been well-established in adults, there remains a paucity in radiographical data to define normal and pathoanatomical juvenile cohorts. The objectives of this paper were to elucidate the differences in the patellofemoral joint between RPD and typically developed (TD) juvenile populations, using MRI measurements, and determine the best independent and combined predictors of RPD.MethodsA prospective, cross-sectional study was conducted with 25 RPD and 24 TD participants aged between 8 and 19 years. MR images were obtained to assess common measures of lower limb alignment, patellofemoral alignment, and trochlear dysplasia.ResultsSignificant differences were evident for acetabular inclination, tibial-femoral torsion, tibial tubercle-to-trochlear groove (TT-TG) distance, lateral patellar tilt (LPT), cartilaginous sulcus angle (CSA) and bisect offset ratio (BOR). CSA and BOR were included in the final predictive model, which correctly classified 89.4% of RPD cases.ConclusionRadiographical parameters that stratify risk of RPD in adults are also able to predict RPD in the pediatric population (TT-TG, LPT, CSA and BOR). Together, CSA and BOR accurately identified 89.4% of RPD. These measures should be included in the evaluation of pediatric patients who present with patellar dislocation.Level of evidenceLevel II.

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 Increased tibial tubercle-trochlear groove and patellar height indicate a higher risk of recurrent patellar dislocation following medial reefing

2021 ◽  
Author(s):  
Marc-Daniel Ahrend ◽  
Tobias Eisenmann ◽  
Moritz Herbst ◽  
Boyko Gueorguiev ◽  
Gabriel Keller ◽  
...  
Keyword(s):  
Patellar Dislocation ◽  
Recurrent Dislocation ◽  
Patellar Height ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Recurrent Patellar Dislocation ◽  
Patellar Tilt ◽  
Level Of Evidence ◽  
Sulcus Angle ◽  
Patellar Shift

Abstract Purpose Identifying anatomical risk factors on recurrent dislocation after medial reefing is important for deciding surgical treatment. The present study aimed to retrospectively analyze the preoperative magnetic resonance imaging (MRI)-based parameters of patients treated with medial reefing and whether these parameters lead to a higher risk of recurrent dislocation. Methods Fifty-five patients (18.6 ± 6.6 years) who underwent medial reefing after primary traumatic patellar dislocation (84% with medial patellofemoral ligament [MPFL] rupture) were included. Patients were followed up for at least 24 months postoperatively (3.8 ± 1.2 years) to assess the incidence of recurrent patellar dislocation. In patients without recurrent dislocation, the Kujala and subjective IKDC scores were assessed. Moreover, the tibial tubercle-trochlear groove (TT-TG), sulcus angle, patellar tilt, patellar shift, and lateral trochlea index (LTI) were measured. The patellar height was measured using the Caton-Dechamps (CDI), Blackburne-Peel (BPI), and Insall-Salvati index (ISI). The cohort was subclassified into two groups with and without recurrent dislocation. Differences between groups were analyzed with respect to the MRI parameters. Results Forty percent had a pathological sulcus angle of > 145°, 7.2% had an LTI of < 11°, 47.3% had a patellar tilt of > 20°, and 36.4% had a TT-TG of ≥ 16 mm. Increased patellar height was observed in 34.5, 65.5, and 34.5% of the patients as per CDI, BPI, and ISI, respectively. Nineteen (34.5%) patients suffered from recurrent dislocation. Compared with patients without recurrent dislocation, those with recurrent dislocation had a significantly lower LTI (p = 0.0467). All other parameters were not significantly different between the groups. Risk factor analysis showed higher odds ratios (OR > 2), although not statistically significant, for MPFL rupture (OR 2.05 [95% confidence interval 0.38–11.03], LTI (6.6 [0.6–68.1]), TT-TG (2.9 [0.9–9.2]), and patellar height according to ISI (2.3 [0.7–7.5]) and CDI (2.3 [0.7–7.5])). Patients without recurrent dislocation had a Kujala score of 93.7 ± 12.1 (42–100) points and an IKDC score of 90.6 ± 11.7 (55.2–100) points. Conclusion Anatomical, MRI-based parameters should be considered before indicating medial reefing. A ruptured MPFL, an LTI < 11°, a TT-TG ≥ 16 mm, a patellar tilt > 20 mm, and an increased patellar height according to ISI and CDI were found to be associated, although not significantly, with a higher risk (OR > 2) of recurrent patellar dislocation after medial reefing. Thorough preoperative analysis is crucial to reduce the risk of recurrent dislocation in young patient cohorts. Level of evidence Level IV

scholarly journals Identifying Patients With Patella Alta and/or Severe Trochlear Dysplasia Through the Presence of Patellar Apprehension in Higher Degrees of Flexion

2020 ◽  
Vol 8 (6) ◽  
pp. 232596712092548
Author(s):  
Matthew Colatruglio ◽  
David C. Flanigan ◽  
Sarah Harangody ◽  
Robert A. Duerr ◽  
Christopher C. Kaeding ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Patellar Instability ◽  
Trochlear Dysplasia ◽  
Patella Alta ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Type B ◽  
Level Of Evidence ◽  
Sulcus Angle ◽  
Recurrent Patellar Instability

Background: Recurrent patellar instability is frequently treated surgically with reconstruction of the medial patellofemoral ligament (MPFL). Patients with significant patella alta, trochlear dysplasia, and/or an elevated tibial tubercle–trochlear groove (TT-TG) distance may benefit from a concurrent bony procedure such as tibial tubercle osteotomy or trochleoplasty. The indications to perform such procedures are traditionally based on imaging criteria but remain controversial. Patellar apprehension is common in patients with patellar instability but typically resolves in higher degrees of knee flexion. Hypothesis: The persistence of patellar apprehension at greater than 60° of knee flexion is associated with patella alta, an increased TT-TG distance, and trochlear dysplasia. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 76 patients with recurrent patellar instability were prospectively identified in a sports medicine clinic. Patellar apprehension was evaluated in each patient. Apprehension was defined as the patient reporting that the patella felt unstable to lateral patellar translation. Apprehension was first assessed at full knee extension and repeatedly assessed as the knee was flexed in 10° intervals, as measured using a goniometer. The degree of flexion at which patellar apprehension disappeared was recorded. Plain radiographs and magnetic resonance imaging (MRI) scans were obtained for all patients. Patellar height was assessed with the Caton-Deschamps (CD) index, and trochlear morphology was assessed through measurements of the sulcus angle and depth on MRI and classified using the Dejour classification system. Imaging measurements of patients in whom apprehension resolved by 60° of knee flexion were compared with measurements for those with apprehension that persisted deeper into flexion. Results: Apprehension resolved by 60° of flexion in 56 patients and persisted into deeper flexion in 20 patients. The patients with a delayed resolution of apprehension demonstrated a higher CD index; elevated TT-TG distance; increased sulcus angle; decreased sulcus depth; and higher incidence of Dejour type B, C, or D dysplasia (all P < .05). Of the 20 patients with a delayed resolution of apprehension, 18 had either Dejour type B, C, or D dysplasia or a CD index of at least 1.30. A delayed resolution of apprehension was present in 11 of the 16 patients with Dejour type B, C, or D dysplasia. Conclusion: Overall, 90% of patients with significant patella alta and the majority of patients with high-grade trochlear dysplasia demonstrated patellar apprehension that persisted beyond 60° of knee flexion. Additionally, 90% of patients with persistent apprehension had significant patella alta and/or trochlear dysplasia. Further work is needed to evaluate the utility of these findings to inform surgical decision-making in this population.

scholarly journals ASSOCIATION BETWEEN RADIOGRAPHIC PARAMETERS AND OSTEOCHONDRAL DAMAGE IN PATIENTS WITH PATELLAR INSTABILITY

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0048
Author(s):  
Lilah Fones ◽  
Regina Kostyun ◽  
James Pace
Keyword(s):  
Patellar Instability ◽  
Trochlear Dysplasia ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Odds Ratios ◽  
Sulcus Angle ◽  
Radiographic Parameters ◽  
Radiographic Measurements ◽  
Patient Reported ◽  
Adolescent Patients

Objectives: Osteochondral damage is a potential consequence of patellar instability that is associated with an increased risk of arthritis and lower patient reported outcomes. Currently, there is little evidence of risk factors associated with osteochondral damage in the setting of patellar instability. The purpose of this study was to identify the association of patient demographics, chronicity of patellar instability, and radiographic measurements with osteochondral damage in adolescent patients with patellar instability. Methods: Upon obtaining Institutional Review Board approval, a chart review was conducted to identify patients 18 years of age and younger treated for patellar instability between 2013 and 2018 at a tertiary referral center. Patients with both acute traumatic and chronic recurrent dislocations with magnetic resonance imaging (MRI) results available were included. Patients were excluded if they had a previous ipsilateral patellar instability surgical intervention. MRI exams were reviewed, and measurements were conducted for Caton-Deschamps (CD) ratio, proximal tibial tubercle to trochlear groove (pTT-TG), distal tibial tubercle to trochlear groove (dTT-TG), lateral trochlear inclination (LTI), lateral patellar inclination (LPI), and sulcus angle. Logistical regression was conducted using binary outcome of presence or absence of osteochondral damage (Statistical Analysis Software, Cary, NC). Odds ratios were calculated for parameters that were statistically significant (p<0.05). Results: A total of 129 knees and 122 patients (average age at first visit 14.4±3.0, 51% female) were identified with patellar instability, of which 53% had osteochondral damage. Approximately one third of patients (67%) were treated with surgical management. There was no association identified between osteochondral damage and sex, age, BMI, symptom duration, physeal status, or number of dislocation (acute vs chronic). Of the radiographic measurements evaluated, LTI, LPI, sulcus angle and dTT-TG all had a statistically significant association with the presence of osteochondral damage (Table 1). Every 1-unit decrease in LTI (more trochlear dysplasia) was associated with a 6% increased chance of osteochondral damage. Every 1-unit increase in LPI, sulcus angle, and dTT-TG is associated with an increased chance of osteochondral damage of 5.5%, 5.8%, and 11.3%, respectively. The CD ratio and pTT-TG had no association with osteochondral damage. Confidence intervals, p-values, and odds ratios are presented in Table 1. Conclusions: There is an association between radiographic parameters, particularly those that correlate with higher levels of trochlear dysplasia, and osteochondral damage in adolescent patients with patellar instability, but no association with being either an acute or chronic dislocator. Clinically, this may impact the management of patients presenting with patellar instability and no radiographic evidence of osteochondral damage. In these patients, clinicians may have a lower threshold for surgical interventions in those with higher levels of trochlear dysplasia as evidenced by decreased LTI and an increased LPI, sulcus angle, and dTT-TG.

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