The treatment of osteonecrosis in SLE patients is similar to that of osteonecrosis due to other causes. The goal of the treatment of osteonecrotic lesions is to preserve joint integrity by preventing bone collapse.
When osteonecrosis involves less than 10% of the femoral head or less than 1/3 of the weight-bearing portion the outcome is usually favourable and surgical treatment is not required [1
]; the conservative treatment includes analgesics and the use of devices to allow nonweight bearing; these measures are usually effective in alleviating pain.
In case of symptomatic lesions surgical treatment is usually required.
Core decompression technique was performed for the first time in 1962 in order to reduce bone marrow pressure and to improve perfusion of ischemic bone [54
]. Mont et al. treated by core decompression 31 hips in 18 SLE patients; in 21 cases (68%) a subsequent total joint replacement was required; all these cases were in an advance stage of the disease. The authors concluded that an early detection of the lesion and a prompt treatment are crucial to obtain optimal results [55
]. Core decompression is usually ineffective when osteonecrosis involves more than 25% of the femoral head or more than 2/3 of the weight-bearing portion [1
]. Core decompression was successfully performed in cases of osteonecrosis of the knee and of the talus in the precollapsed stages [55
Concentrated autologous bone marrow aspirate transplantation following core decompression was successfully performed in 8 out 9 SLE cases with osteonecrosis of the femur head involving more than 2/3 of the weight-bearing portion; only the patient who showed an advanced stage lesion failed to obtain benefit and later required joint replacement. Non perioperative complications were observed [57
Another option is free vascularised fibular grafting; this procedure was applied in 80 osteonecrotic lesions of the hip among 50 SLE patients who were followed at least for two years after the procedure, on average for 4.3 years; none of the cases required hip arthroplasty, suggesting that free vascularised fibular grafting may allow to maintain joint function [58
Transtrochanteric anterior rotational osteotomy demonstrated to be effective in a long-term study, showing a hip survival rate of 73.7% after 25 years from the surgical approach [59
A 19-year-old woman affected by SLE who developed bilateral femur osteonecrosis that affected more than 2/3 of the weight-bearing area was treated with extracorporeal shockwave under general anesthesia obtaining significant pain relief, hip functional amelioration, and reduction of bone edema [60
]. Shockwave treatment may favour neovascularization through an increased release of angiogenic factors [61
] and may enhance bone mass and bone strength as demonstrated in rabbits [62
]. After this first favourable experience, 15 SLE patients with 26 hips affected by osteonecrosis were treated with extracorporeal shockwave; hip replacement was necessary in 12% of the cases. The outcome was similar to that observed in a group of non-SLE patients with osteonecrosis [63
The outcome of hip arthroplasty in SLE-associated osteonecrosis is not different from that observed in other indications; an overall survival probability of 94.6% at 5 years and of 81.8% at 9 years was reported with minimal perioperative morbidity [64
]. In 19 SLE patients who underwent 26 hip arthroplasty interventions, two early, nonrecurrent dislocations, and one low-grade prosthetic infection were described [65
Less favourable results were obtained for knee arthroplasty in SLE patients with osteonecrosis; a good outcome was reported in 11 out of 25 cases. No differences were found when patients were stratified by amount of corticosteroid use, cemented versus cementless fixation, and SLE activity [66
mg per week was tested in a randomized placebo controlled study in 40 patients affected by unilateral or bilateral nontraumatic osteonecrosis of the femoral head with a necrotic area larger than 30%. Only 2 out of 29 femoral heads collapsed in the group treated with alendronate in comparison with 19 out of 25 femoral heads in the control group. Joint replacement was necessary in 1 alendronate-treated patient as compared with 16 cases of the placebo group [67
]. A prospective study evaluating the effectiveness of the contemporaneous administration in SLE patients of high corticosteroid dose with bisphosphonate should be planned in order to establish if this class of drugs may prevent the onset or may halt the progression of osteonecrotic lesions.
The preventive strategy for osteonecrosis development in SLE patients requiring high corticosteroid dose to control disease activity has been seldom studied. Sixty newly diagnosed SLE patients treated with ≥40
mg of prednisolone daily were alternatively assigned to two options, a warfarin group and a control group; warfarin was given together with the initiation of corticosteroid therapy. Silent and symptomatic osteonecrosis developed in 21% and 4.8% of the hips in the warfarin group, respectively, and in 33% and 14% of the hips in the control group, respectively. Despite the lack of a statistically significant difference, the observed results indicate that larger studies are warranted in order to verify the efficacy of anticoagulation therapy for preventing osteonecrosis at least in SLE patients [68
According to the actual understanding of the pathophysiology of osteonecrosis, some preventing benefits might be expected from the treatment with lipid lowering agents, antiplatelet drugs, and antiresorptives. However, in a small study in SLE patients with disease flare requiring increased corticosteroid dosage, no beneficial effects were observed with the concomitant administration of statin, antiplatelet, and bisphosphonate [69