Avascular necrosis (AVN) is a serious complication
of high-dose chemotherapy for haematological malignancy in childhood.
In order to describe its incidence and main risk factors and to
evaluate the current treatment options, we reviewed 105 children
with a mean age of 8.25 years (1 to 17.8) who had acute lymphoblastic
or acute myeloid leukaemia, or a non-Hodgkin’s lymphoma. Overall,
eight children (7.6%) developed AVN after a mean of 16.8 months (8
to 49). There were four boys and four girls with a mean age of 14.4
years (9.8 to 16.8) and a total of 18 involved sites, 12 of which
were in the femoral head. All these children were aged >
nine years
(p <
0.001). All had received steroid treatment with a mean cumulative
dose of prednisone of 5967 mg (4425 to 9599) compared with a mean
of 3943 mg (0 to 18 585) for patients without AVN (p = 0.005). No
difference existed between genders and no thrombophilic disorders
were identified. Their initial treatment included 11 core decompressions
and two bipolar hip replacements. Later, two salvage osteotomies
were done and three patients (four hips) eventually needed a total
joint replacement. We conclude that AVN mostly affects the weight-bearing
epiphyses. Its risk increases with age and higher steroid doses.
These high-risk patients may benefit from early screening for AVN. Cite this article:
The treatment of osteonecrosis of the femoral head (FHN) is controversial. It mainly occurs in young patients in whom total hip replacement is best avoided because of an increased risk of revision. The objective of this long-term follow-up study was to evaluate the outcome of intertrochanteric flexion osteotomy as a hip joint preserving operation for FHN. Over a 19-year period we carried out 70 intertrochanteric flexion osteotomies for FHN in 64 patients. The mean follow-up was 10.4 years (3.0 to 20.3). The overall mean Harris hip score increased from 51 points preoperatively to 71 points postoperatively. Six patients (9%) developed early postoperative complications. A total of 19 hips (27%) underwent total hip arthroplasty at a mean of 8.7 years after osteotomy. The five-year survival rate was 90%. Survival rates of hips in Ficat stage 2 were higher than those in stages 3 or 4. Hips with a preoperative necrotic angle of <
200° had a better survival probability than those with a necrotic angle >
200°. Our findings suggest that flexion osteotomy is a safe and effective procedure in Ficat stage 2 and 3 FHN, preferably with a necrotic angle of <
200°.
Treatment with corticosteroids is a risk factor for non-traumatic avascular necrosis of the femoral head, but the pathological mechanism is poorly understood. Short-term treatment with high doses of methylprednisolone is used in severe neurotrauma and after kidney and heart transplantation. We investigated the effect of such treatment on the pattern of perfusion of the femoral head and of bone in general in the pig. We allocated 15 immature pigs to treatment with high-dose methylprednisolone (20 mg/kg per day intramuscularly for three days, followed by 10 mg/kg intramuscularly for a further 11 days) and 15 to a control group. Perfusion of the systematically subdivided femoral head, proximal femur, acetabulum, humerus, and soft tissues was determined by the microsphere technique. Blood flow in bone was severely reduced in the steroid-treated group. The reduction of flow affected all the segments and the entire epiphysis of the femoral head. No changes in flow were found in non-osseous tissue. Short-term treatment with high-dose methylprednisolone causes reduction of osseous blood flow which may be the pathogenetic factor in the early stage of steroid-induced osteonecrosis.
