Patellar tracking, measurements may predict pediatric patellar osteochondritis dissecans
Key takeaways:
- Increased tibial tubercle-trochlear groove distance and sulcus angles were associated with patellar osteochondritis dissecans.
- Researchers compared patellar vs. medial femoral condyle osteochondritis dissecans.
Published results showed increased tibial tubercle–trochlear groove distance and increased cartilaginous and bony sulcus angles were associated with patellar osteochondritis dissecans in pediatric patients.
In addition, researchers found patients with these abnormal morphologies and patellar osteochondritis dissecans (OCD) lesions may be at increased risk for patellar dislocations compared with a matched cohort of patients with medial femoral condyle OCD.
“Patellar OCD is a rare type of knee OCD. The estimated prevalence of patellofemoral OCD lesions ranges from 1% to 5%,” Emilie Lijesen, BS, and colleagues from Hospital for Special Surgery, wrote in the study. “Although the exact cause of OCD lesions is unknown, repetitive microtrauma and joint loading have been proposed as mechanisms, especially given the propensity for OCD lesion formation in the knees of young athletes.”
Lijesen and colleagues performed a case series analysis of patients aged 18 years or younger who were diagnosed with either patellar or medial femoral condyle OCD at a single center between January 2016 and May 2023. Patients were matched 1:2 based on age and sex. The patellar OCD cohort consisted of 40 knees from 34 patients (mean age 13.9 years) and the medial femoral condyle OCD cohort consisted of 80 knees from 73 patients (mean age, 14.1 years).
According to the study, Lijesen and colleagues used MRI to assess Caton-Deschamps index, cartilaginous bony height, trochlear depth, patellar tilt, lateral patellar displacement, cartilaginous sulcus angle, bony sulcus angle and tibial tubercle-trochlear groove (TT-TG) distance.
Overall, the patellar OCD cohort had increased mean TT-TG distance (13.35 mm vs. 11.55 mm), mean cartilaginous sulcus angle (150.63° vs. 128.09°) and mean bony sulcus angle (144.7° vs. 137.37°) compared with the medial femoral condyle OCD cohort.
Lijesen and colleagues found 40% of the patellar OCD cohort and 20% of the medial femoral condyle OCD cohort had a TT-TG distance of greater than 15 mm. They also noted the patellar OCD cohort had a 3.7 times increased risk for subsequent patellar dislocations vs. the medial femoral condyle OCD cohort.
“These findings should caution surgeons that patients presenting with a patellar OCD lesion, particularly those requiring operative treatment, may develop patellar instability,” Lijesen and colleagues concluded.
Collapse