Changes in bone scans after anterior cruciate ligament reconstruction: a prospective study.

BACKGROUND Whether anterior cruciate ligament reconstruction retards the progression of osteoarthrosis is not established. Bone scintigraphy can be useful for monitoring the course of osteoarthrosis. Bone scan findings are abnormal in the majority of patients with anterior cruciate ligament deficiency. Three uptake patterns can be distinguished. HYPOTHESIS Reconstruction corrects the three abnormal bone scan patterns seen in patients with anterior cruciate ligament deficiency. STUDY DESIGN Prospective cohort study. METHODS We performed bone scintigraphy in 80 patients, before and 2 years after anterior cruciate ligament reconstruction. RESULTS Reconstruction consistently corrected type 2 bone scan pattern (meniscus scan) but not type 1 and 3 patterns (osteoarthrosis and cartilage ulcer scan). Correction of all three patterns decreased among patients who had longer duration of anterior cruciate ligament deficiency and was more reliable for the combined uptake of all three patterns among patients who had less than 6 months of deficiency. CONCLUSION These findings indicate anterior cruciate ligament reconstruction protects the menisci. Reconstruction may be best performed within 6 months after injury.