Comparison of the effect of knee synovectomy in haemophilic patients with 153Sm- and 90Y -labelled hydroxyapatite 1 year after

Summary To compare the use of 740 Mbq (20 mCi) of 153Sm and 185 Mbq (5mCi) of 90Y, both labelling hydroxyapatite (HA), for knee synovectomy in haemophilic patients, 1 year after the intervention. Thirty three men (36 knees) were studied, divided into two groups: 1 – treatment using 740 Mbq of 153Sm-HA: 20 knees of 18 patients, with mean age of 21.4 ± 13.3 years (ranging from 7 to 56 years) and mean Pettersson score of 5.3; 2 – treatment using 185 Mbq of 90Y-HA: 16 knees of 15 patients, with mean age of 26.3 ± 10.3 (ranging from 7 to 51 years) and mean Pettersson score of 6.3. The following criteria were adopted for the evaluation before and 1 year after synovectomy: reduction in haemarthrosis episodes and pain using a visual analogue scale, as well as improved joint mobility. The occurrence of adverse events in the treatment was also considered. The chi-square, Wilcoxon and Mann–Whitney tests were used with P ≤ 0.05 set as significant. The occurrence of haemarthrosis declined by 65.7% with the use of 153Sm-HA and 82.6% for 90Y-HA, with no statistical difference between the groups (P = 0.632); pain reduction was 42.5% in group 1 and 30.7% in group 2, once again with no statistical difference (P = 0.637). Improvement in joint mobility was not significant for both groups. Two cases of mild reactive synovitis were observed in group 1 and one in group 2, which cleared up without medical intervention. Although the beta energy from 90Y is the gold standard for knee synovectomy, higher activities of 153Sm may be used in places which have only production of this material.