Total Hip Replacement in Sickle Cell Disease Patients with Avascular Necrosis of Head of Femur: A Retrospective Observational Study

BACKGROUND: Femoral head avascular necrosis leads to osteoarthritis of the hip joint and affects its functional capacity in sickle cell disease patients. The functional outcomes of total hip replacement (THR) on patients with congruous joints who underwent hip replacement after having a failed joint preservation surgery are unknown. This study aimed to compare the functional outcomes of THR in patients with sickle cell disease having avascular necrosis with and without loss of hip joint congruency. METHODS: This retrospective study included 35 patients (age, 20–52 years; 18 males and 17 females) who underwent uncemented THR. Patients were divided into Group-A (n = 18, good hip joint congruency) and Group-B (n = 17, obliterated hip joint congruency). The Harris Hip Score (HHS) was used to assess functional outcomes. All patients were followed up at 6-weekly intervals then 6-monthly intervals. RESULTS: The mean follow-up period was 8.26 ± 3.01 years. The mean preoperative HHSs of Group-A and Group-B were 45.22 ± 3.021 and 25.94 ± 4.437, respectively. Postoperatively, a subsequent increase in HHS was found in both groups, and a significant difference between the groups was observed at 6 weeks (p < 0.0001*) and 1 year (p < 0.0006*). Interestingly, HHS was not significantly different (p = 0.0688) at 5-year follow-up between the groups. The differences in HHS within the group at each subsequent follow-up were also statistically significant (ANOVA, p < 0.0001*). CONCLUSION: A significant improvement was observed with THR in both groups. Nevertheless, the flattened hip joint congruency group showed significantly better HHS improvements than the normal congruency groups. These findings may aid in the decision-making capabilities of the surgeons.