Selective hemiepiphyseodesis for patellar instability with associated genu valgum

Purpose. The aim of the present study was to investigate tibial tuberosity-trochlear groove (TT-TG) distance dynamics in patients with patellofemoral pain (PFP) and pain free individuals by using full weight bearing kinematic magnetic resonance imaging (MRI) And correlation with patellar instability. Materials and methods. 51 female individuals with PFP and 26 pain free female individuals participated in the study. The kinematic MRI was performed with 1,5 T MRI unit and full-weight bearing. TT-TG distance, bissect offset (BSO) and patellar tilt angle (PTA) were measured in steps of 10° between 50° of flexion to full extension. Results. The TT–TG was higher in PFP patients compared to volunteers’ from 40° to full extension. This difference was statistically significant (p<0.01). PFP patients demonstrated statistically significantly greater TT-TG distance increase from 30° to full extension. BSO and PTA were moderately correlated to TT-TG from 20° of flexion to full extension. Conclusion. TT-TG distance is dynamic and increases significantly during extension in patients with PFP and pain free individuals, depending on knee flexion angle. It shows different pattern of dynamics in PFP group. TT-TG distance is associated with patellar instability (BSO and PTA) at low degrees of flexion.

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

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120973665 ◽

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.

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Decreasing Thickness of Partial Lateral Trochlear Cartilage in Patients with Patellar Instability

Orthopaedic Surgery ◽

10.1111/os.12971 ◽

2021 ◽

Author(s):

Chongyi Fan ◽

Ming Li ◽

Guangmin Yang ◽

Xunkai Feng ◽

Fei Wang

Keyword(s):

Patellar Instability

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Temporary hemiepiphysiodesis using an eight‐plate implant for coronal angular deformity around the knee in children aged less than 10 years: efficacy, complications, occurrence of rebound and risk factors

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-03915-w ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Zhen-Zhen Dai ◽

Zhen-Peng Liang ◽

Hao Li ◽

Jing Ding ◽

Zhen-Kai Wu ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Deformity Correction ◽

Genu Valgum ◽

Angular Deformity ◽

Screw Loosening ◽

Logistic Regression Models ◽

The Mean ◽

Low Incidence ◽

Angular Deformities

Abstract Background Temporary hemiepiphysiodesis (TH) using an eight-Plate implant is one of the most common surgeries used for the correction of coronal angular deformities around the knee in adolescents. However, few studies have focused on children aged less than 10 years treated with TH using an eight-Plate implant. The purpose of this study was to investigate the efficacy, correction velocity, and complications of TH with an eight-Plate implant as well as the occurrence of rebound and risk factors in this population. Methods This retrospective study included a total of 135 physes (101 knees) from 66 children (mean age of 4.69 years old, range from 1 to 10 years old) who underwent TH with an eight-Plate implant to correct coronal genu angular deformities in our hospital. Related clinical factors were recorded and analysed by multivariable linear and logistic regression models. Results The mean deformity correction period was 13.26 months, and the mean follow-up after eight-Plate removal was 12.71 months. In all, 94.06% (95/101 knees) of the genu angular deformities were completely corrected. Non-idiopathic genu angular deformity was found to be an independent risk factor for deformity correction failure (odds ratio (OR) = 2.47). The femoral correction velocity was significantly higher than the tibial correction velocity (1.28° vs. 0.83° per month, p < 0.001). After adjustment for other factors, younger children had higher correction velocities in the distal femur; however, genu valgum and idiopathic deformities were associated with higher correction velocities in the proximal tibia. In addition, we found three (3/101, 2.97%) knees with genu valgum that experienced rebound after removal of the eight-Plate, while five (5/101, 4.95%) knees with non-idiopathic genu angular deformity experienced screw loosening. No other complications were found, and non-idiopathic deformity was the only risk factor for complications (OR = 3.96). No risk factor was found for rebound in our study. Conclusions TH using an eight-Plate implant is an effective procedure for coronal genu angular deformities with a low incidence of complications and rebound in patients younger than 10 years old. For this population, TH using an eight-Plate should be considered as soon as the deformity stops responding to conservative treatments. The parents of children younger than 10 years of age with non-idiopathic deformities should be informed preoperatively that the deformity may be prone to correction failure or screw loosening after eight-Plate implantation.

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