To correlate the MRI with the clinical outcomes at 2 years of follow-up of patients affected by isolated patellar cartilage defects, ICRS grade 3/4, treated with the AMIC technique. Our hypothesis was that AMIC technique promotes clinical improvement by relieving symptoms, in addition to leading to neocartilage on MRI.
From January 2014 to April 2019, 13 patients (16 knees) with symptomatic, isolated patellar chondral defects confirmed by MRI were included. Exclusion criteria were defects < 2cm2, age < 15 years and > 55 years, and patellofemoral or tibiofemoral malalignment. Patients who required additional surgeries were excluded from the study. KOOS, EuroQol-5D, Kujala score and VAS for pain were used as clinical outcomes measures. Diagnosis and follow-up were performed by MRI, using the modified MOCART scale. Statistical data analysis was performed using SPSS (Student Version-Windows 16.0).
Sample: 8 females/5 males, mean age 39.93±8,53 years (range 23-51), mean BMI 27,5 ± 4,71 kg/m2. ICRS grade 4 in 14, grade 3 in one patient. One patient was lost to follow-up. Mean defect surface area 2.63±0.92 cm2 (range 2-4 cm2).
Clinical improvement became statistically significant for VAS (p=0.0001), KOOS (p=0.014), EQ-5D (p=0.0003), and EQ-5D-VAS (p=0.0007). Not statistically significant differences were found for Kujala (p=0.17).
To correlate MRI with clinical results, patients were divided into two groups according to the VAS improvement. There were no significant differences between the two groups in relation to defect filling, cartilage interface, bone interface, integration, bone marrow edema, and surface quality. There were significant differences in signal intensity, structure, subchondral lamina, and osteophyte prevalence.
AMIC presents satisfactory clinical results and promotes neocartilage formation in the medium term, confirmed by MRI, thus fulfilling the hypothesis raised.
Furthermore, it is shown that changes observed on MRI from the baseline to 2 years of follow-up can predict the patient’s clinical outcome.