Bone imaging after acute knee hemarthrosis.

Follow-up evaluations were carried out in 84 patients examined 5-8 years after sustaining an acute traumatic hemarthrosis of the knee. The initial examination performed within 2 weeks of injury had revealed 18 patients with a stable knee and 66 with anterior instability. Twelve of the patients underwent anterior cruciate ligament reconstruction within 3 months of injury and 11 more did so between 1 and 3 years after injury. To document joint deterioration at follow-up, bone scintigraphy and conventional anteroposterior, lateral, and tunnel X-rays were taken. Medial, lateral, patellofemoral and patellar uptake in bone scintigraphy was graded from 0 to 4. Six radiological variables were graded at eight different sites. Sixty-three patients (75%) had a positive bone scan and 69 patients (82%) showed radiological changes. Bone scan and X-ray scores were both significantly higher in the reconstructed knees.