Initial symptoms and delayed diagnosis of osteosarcoma around the knee joint

To identify initial symptoms of osteosarcoma around the knee joint.

Records of 19 men and 11 women aged 9 to 34 (mean, 17) years with osteosarcoma around the knee joint were reviewed. Each patient was interviewed (for a mean of 1.5 hours), and a detailed history of symptom onset recorded.

In all patients, the first symptom was pain, which was more pronounced on weight bearing in 16 (53%) of them and was worse at night in 11 (37%). Swelling was noticed in 28 patients (a mean of 7 weeks after pain onset). 16 (53%) of the patients had a history of minor trauma around the time of symptom onset. 20 (67%) of the patients had a limp, in 9 of whom it was not associated with pain on weight bearing; only 2 (7%) had a pathological fracture. The mean interval from the onset of symptoms (pain) to presentation was 10 (range, 0-49) weeks. The mean interval from presentation to radiography was 3 (range, 0-20) weeks; in 8 patients this interval exceeded 3 weeks despite a noticeable swelling. The mean interval from radiography to referral to our hospital was 2 (range, 0-14) weeks. Together with the 2 weeks for diagnostic workup and biopsy, the mean total delay was 17 (range, 4-55) weeks.

Physicians should be aware of the symptoms of osteosarcoma and promptly refer patients to tumour centres, especially adolescents, those who present with pain that may be worse at night and on weight bearing, and those in whom a swelling and/or a limp is evident.