Patients with bilateral patellar instability have multiple and symmetric risk factors in each knee.

PURPOSE: Bilateral involvement is common in patients with patellar instability. The management of bilateral patellar instability is associated with increased complication rate. The higher complication rate in this cohort may be related to the presence of underlying anatomic risk factors. The purpose of the study was to evaluate the presence and side-to-side differences in risk factors between knees in bilateral patellar instability. METHODS: In a retrospective study (2008-2017), demographic information, characteristics of patellar dislocation and anatomic risk factors on MRI (trochlear dysplasia, patellar height, tibial tubercle lateralization, patellar tilt, sulcus angle, bump height) were evaluated in both knees of all patients (n = 32, 15 males and 17 females) with bilateral patellar instability. The risk factors were analyzed based on established cut off values and were compared between gender, laterality and more symptomatic (index) knee. Knee symmetry and absolute differences between risk factors for both knees were analyzed. RESULTS: The mean age of 32 patients was 14.6 ± 2.3 years. Of the 4 major anatomic risk factors, the most common were trochlear dysplasia in 59/64 (92.1%) knees and patella alta in 51/64 (79.7%) knees. Tibial tubercle lateralization was the least common risk factor being present in 8/64 (12.5%) knees. Of 64 knees, 55 (85.9%) had 2 or more risk factors and 30 (46.8%) had 3 or all 4 risk factors present. There were no significant differences in risk factors based on gender, laterality or index knee. There was symmetry between paired knees for 31/32 (96.8%) patients for trochlear depth, 29/32 (90.6%) for patellar tilt, 27/32 (84.3%) for TT-TG distance and 25/32 (78.1%) for patellar height. There were no significant differences in absolute measurements between knees for any of the risk factors. CONCLUSION: Patients with bilateral instability had multiple risk factors, with trochlear dysplasia being the most common and increased TT-TG distance being the least common. Majority of patients had 2 or more risk factors and about half had 3 or 4 risk factors in each knee. There was symmetry between paired knees for each risk factor without any significant differences between the index knee compared to the contralateral knee. LEVEL OF EVIDENCE: Level III.

Patellofemoral Instability in Children: Correlation Between Patellofemoral Incongruence, Mechanism of Injury, and Cartilage Damage.

OBJECTIVE. The objective of our study was to assess correlation between patellofemoral incongruency and injury mechanism, recurrence, bilaterality, and cartilage damage in patients with patellofemoral instability (PFI). MATERIALS AND METHODS. Ninety-four knee MRI examinations (10 bilateral) of 84 patients with PFI (47 female and 37 male patients; mean age ± SD, 15.0 ± 2.5 years) who had patella dislocation and medial patellofemoral ligament reconstruction (MPFLR) and 66 examinations of age- and sex-matched control subjects were reviewed. The PFI group was subclassified on the basis of injury, recurrence, and bilaterality. Patellofemoral congruence was assessed in both groups with the following MRI measurements: lateral femoral trochlear inclination angle, femoral sulcus depth, medial-to-lateral facet ratio, distance between tibial tuberosity (TT) and trochlear groove (TG), and patellar tendon ratio. Patella cartilage damage was assessed in the PFI group using conventional MRI (International Cartilage Repair Society grade 0-4) and T2 relaxation time mapping at three locations. MRI measurements were compared between groups and subgroups (Wilcoxon rank sum test) and were correlated with cartilage damage (Spearman correlation). RESULTS. All MRI measurements were significantly different between the group with PFI and the group without PFI (p < 0.0001). The bilateral PFI group had significantly increased TT-TG distance (mean, 15.9 vs 13.1 mm, p < 0.05) and patellar tendon ratio (mean, 1.6 vs 1.4, p < 0.05) compared with the unilateral PFI group. The TT-TG distance positively correlated with T2 values of medial and lateral patella cartilage. There were no differences between other subgroups and no correlation between other MRI measurements and the severity of cartilage damage. CONCLUSION. In patients with PFI, the severity of patellofemoral incongruence was not associated with injury mechanism or cartilage damage. However, increased lateralization of the patellar tendon (TT-TG distance) and patella alta (patellar tendon ratio) correlated with injury to the contralateral knee requiring bilateral MPFLR.

Femoral trochlea does not remodel after patellar stabilization in children older than 10 years of age.

Trochlear dysplasia is a major risk factor for patellar instability. It has been sparsely reported that the trochlea can remodel when patellar stabilization is performed in skeletally immature patients before the age of 10 years. It is not known whether trochlea can remodel significantly after the age of 10 years. The purpose of the study was to evaluate trochlear remodeling in skeletally immature patients after patellar stabilization surgery, with a focus on children older than 10 years of age. In a retrospective study, knee MRI of 21 patients who had undergone patellar stabilization surgery, were evaluated. Twenty of these 21 patients were older than 10 years of age at time of surgery. The measurements of cartilaginous and bony sulcus angles, trochlear depth, and cartilaginous trochlear bump were compared between preoperative and postoperative MRI, using paired t-tests. In 20 patients older than 10 years of age, the mean cartilaginous sulcus angle change between preoperative and postoperative axial MRI was not significant (2.2°±7.9°, P=0.6). The mean change in the bony sulcus angle value was not significant (3.6°±6.8°, P=0.07). Similarly, there was no significant change in trochlear depth (P=0.8), or size of the trochlear bump (P=0.1). For one patient under 10 years of age at the time of surgery, there was a 21° and a 15° improvement in cartilaginous and bony sulcus angle, respectively. There were no significant changes in the trochlear parameters and trochlear remodeling in patients older than 10 years of age. Patellar stabilization at a younger age (<10 years), may allow for trochlear remodeling. Level of Evidence: Level IV, case series.

Trochlear Dysplasia and Its Relationship to the Anterior Distal Femoral Physis.

BACKGROUND: Trochlear dysplasia is a known risk factor for patellar instability in adolescent patients. A spatial relationship between dysplastic trochlea and anterior distal femoral physis has not been established. The purpose of this study was to investigate this relationship. Our hypothesis was that the position of the dysplastic trochlea and trochlear bump would coincide with the anterior distal femoral physis and that the distance between them would increase with age. METHODS: In a retrospective study, magnetic resonance images of adolescents with trochlear dysplasia were evaluated. Measurements performed included trochlear depth, trochlear bump size, proximal trochlea-physis distance, and trochlear bump-physis distance. Linear regression analyses were performed to correlate the variables with increasing age. RESULTS: In total, 175 knees (160 patients) with trochlear dysplasia were included. The mean trochlea-physis distance was 4.50 mm (SD=1.93) and it increased with age (slope=0.26; P<0.01). The lateral aspect of trochlea was proximal to the physis in 24 (13.7%) knees and was at the level of the physis in 31 (17.7%) knees. The size of trochlear bump increased with age (slope=0.15; P=0.01). The bump-physis distance increased with age (slope=0.41; P<0.01). CONCLUSIONS: The dysplastic trochlea is closely related to the anterior distal femoral physis. The distance between the dysplastic trochlea and femoral physis increases with age. The close relationship between proximal aspect of trochlea and anterior distal femoral physis should be considered when trochlear surgery is planned in skeletally immature patients. LEVEL OF EVIDENCE: Level II.

Pharmacotherapy for generalized anxiety disorder in adult and pediatric patients: an evidence-based treatment review.

INTRODUCTION: Generalized anxiety disorder (GAD) often begins during adolescence or early adulthood and persists throughout the lifespan. Randomized controlled trials support the efficacy of selective serotonin and selective serotonin norepinephrine reuptake inhibitors (SSRIs and SNRIs, respectively), as well as benzodiazepines, azapirones, anti-adrenergic medications, melatonin analogs, second-generation antipsychotics, kava, and lavender oil in GAD. However, psychopharmacologic treatment selection requires clinicians to consider multiple factors, including age, co-morbidity, and prior treatment. Areas covered: The authors review the literature concerning pharmacotherapy for pediatric and adult patients with GAD with specific commentary on the efficacy and tolerability of selected agents in these age groups. The authors describe an algorithmic approach to the pediatric and adult patient with GAD and highlight considerations for the use of selected medications in these patients. Expert opinion: In adults with GAD, SSRIs and SNRIs represent the first-line psychopharmacologic treatment while second-line pharmacotherapies include buspirone, benzodiazepines, SGAs, and pregabalin. In pediatric patients with GAD, SSRIs should be considered the first line pharmacotherapy and psychotherapy enhances antidepressant response.

The Growth of Trochlear Dysplasia During Adolescence.

BACKGROUND: Femoral trochlear dysplasia is a known risk factor for patellar instability. The growth pattern of the normal trochlea is known, but there have been no studies investigating the growth and development of the dysplastic trochlea. The purpose of this study was to assess the growth pattern of trochlear dysplasia in adolescents. METHODS: In a retrospective analysis, magnetic resonance images of adolescents with patellar instability and trochlear dysplasia were evaluated. These images were measured for lateral and medial condylar height, trochlear height, cartilaginous and bony trochlear bump, and cartilaginous and bony sulcus angle. The type of trochlear dysplasia was classified as per Dejour classification. These measurements were plotted against age, and their growth patterns were evaluated using statistical methods. RESULTS: Of 235 knees with patellar instability, trochlear dysplasia was present in 175 knees (74% knees) and these were further analyzed. With increasing age, the mean lateral and medial condylar heights and mean trochlear height showed statistically significant increase (P<0.01). Cartilaginous trochlear bump (slope=0.15, P=0.013) and bony trochlear bump (slope=0.22, P<0.01) increased with age, with some reaching the pathologic value by age of 15.1 years. After age 11 years, there were no significant changes for cartilaginous and bony sulcus angles (cartilage: slope=0.03, P=0.96; bony: slope=-0.90, P=0.11). The mean cartilaginous sulcus angle was significantly greater than the mean bony sulcus angle (P<0.01). All Dejour types of trochlear dysplasia were present across all age groups. CONCLUSIONS: All linear measurements of trochlear dysplasia (condylar height, trochlear height, trochlear bump) increased with age. However, the shape of trochlear dysplasia, as reflected by sulcus angle and Dejour classification, did not change with increasing age. The shape of trochlear dysplasia is most likely a genetic predisposition and does not necessarily change during skeletal growth. LEVEL OF EVIDENCE: Level II-diagnostic, cross-sectional.