Traumatic haemarthrosis of the knee.

We have investigated a prospective series of 100 acute traumatic haemarthroses of the knee in a general non-athletic population. All the patients had normal radiographs and an aspiration which confirmed the haemarthrosis, before undergoing ligament testing and an arthroscopic examination under anaesthesia. Only one patient had no serious pathology; in the other 99 a total of 193 lesions were recorded. Thirty knees had only one isolated lesion, 69 had combined lesions. This study confirms the serious nature of an acute traumatic haemarthrosis of the knee, even in non-athletic patients.