Beneficial Effect of Hydroxyurea on Avascular Necrosis of Femoral Head in Adult Sickle Cell Disease (Homozygous) - One Year Prospective Study in Orissa, India.

Avascular nacrosis (AVN) of femoral head in Sickle cell Disease, (Homozygous) (SCD) is a progressive and crippling complication seen commonly in India. AVN evolves slowly from cumulative effect of recurrent small episodes of ischemia or infarction within the spongiosa of bone. This complication can occur in the absence of painful crisis for which a satisfactory treatment is yet to be found. Though Hydroxyurea inhibits polymerization of HbS by raising HbF level, its role on AVN of femoral head is not known. Forty six adult SCD with AVN of Femoral head with or without painful crisis received hydroxyurea at a dose of 20 mg/ kg/ day orally while 18 adult SCD with AVN of femoral head, without painful crisis were taken as control. Both the groups received folic acid (1 mg/ day), red cell transfusion and ibuprofen as required. All patients were advised adequate rest and to avoid prolong standing and walking. Clinical, hematological and radiological evaluation were done once in three month for one year.

RESULT: Pain in the hip joints were completely absent both during rest and activity after a median period of 6 months in 11 patients (73.3%,out of 15 cases) in early stage of AVN (minimum necrosis, crescent sign).Radiological abnormalities disappeared completely in these patients after a median period of 9 months. Similar benefits were observed in 7 cases (35%, out of 20 cases) of SCD with segmental collapse of femoral head. Most advanced cases of AVN (complete degeneration and collapse of femoral head) were resistant with least benefits in 3 patients (25.4%, out of 11 cases) with only reduction of pain at rest without any improvement in radiological changes and quality of activity. In control groups though pain was relieved during rest in 4 cases (22.2%) no improvement in radiological picture and pain during activity was observed. Chi square analysis detected a significant rise in Hb F level and benefit in hydroxyurea treated group. Thus hydroxyurea administration in early stages of AVN due to SCD is beneficial.