[MRI in hemarthrosis of the knee joint: assessment of cause of bleeding, injury pattern and therapy].

PURPOSE

Patients with hemarthrosis of the knee were examined by MRI and arthroscopy to identify the bleeding source and to determine surgical or conservative therapy.

METHODS

A prospective study was performed on 120 patients who underwent MRI and arthroscopy. Joint lesions and bleeding sources were documented separately on a standardised form.

RESULTS

Arthroscopy demonstrated a ruptured anterior cruciate ligament in 86%, meniscal tears in 55%, disruption of collateral ligaments in 17%, osteochondral lesions in 5% and tears of capsule or plicae in 13%. Disruption of cruciate ligaments caused haemorrhage in all but three cases. In contrast, only meniscal tears located very adjacent to the meniscal basement had bled. Those types of osteochondral lesions caused haemorrhage characterised on MRI by destruction of the subchondral plate and overlying cartilage. Severe lesions of the knee were diagnosed by MRI in 71% to 100%, slight lesions in 13% to 40% of the cases. Single, combined and bland lesions were accurately diagnosed in MRI which permitted a correct prediction of surgical and conservative therapy in 96% and 80%.

CONCLUSIONS

Morphological criteria in MRI permit identification of bleeding sources in hemarthrosis of the knee. Different lesion patterns can be separated for the planing of therapy.