Preoperative MRI underestimates articular cartilage defect size compared with findings at arthroscopic knee surgery

Campbell AB, Knopp MV, Kolovich GP, et al. · The American Journal of Sports Medicine

MRI underestimated defect area by about 70% versus arthroscopy; 74% of lesions were larger at surgery (mean underestimation about 1 cm²). The scan sets expectations; the scope sets the plan.

Population

77 patients (92 cartilage defects) with preoperative MRI and subsequent knee arthroscopy

Intervention

MRI defect measurement

Comparator

Arthroscopic defect measurement (reference standard)

Limitations

Single-center; measurement comparison, not outcomes; MRI protocols have improved since.