Is COVID-19 an independent risk factor for the development of avascular necrosis of the hip? A retrospective study to evaluate the factors associated with avascular necrosis of the hip in patients who had COVID-19 infection.

PURPOSE: The cumulative effect of hyper-coagulative COVID-19 disease and using steroids leads to increased avascular necrosis (AVN) hip incidence. This study aims to correlate the various factors of COVID-19 infection with the occurrence of AVN hip.

METHODS

It is a retrospective cross-sectional study of non-traumatic AVN hip patients with a history of COVID-19 infection. A total number of 50 patients satisfied the inclusion criteria. The following details were obtained: (a) patient's demographics, (b) COVID-19: interval of infection and groin pain, duration of symptoms, severity, steroid intake, (c) AVN hip: involved side, Ficat-Arlet staging.

RESULTS

The mean age was 36.3 years (range: 20-60), and body mass index (BMI) was 25.13 kg/m2 (range: 18.50-31.50). There were 45 males and five females. Sixty percent (30) of patients managed at home, 24% (12) required admission into the ward, 2% (1) were in ICU only, and 14% (7) admitted to both ICU and ward. The mean interval of COVID-19 infection and onset of hip pain was 359.02 days (range: 10-822 days). Thirty-eight percent (19) patients required steroids (injection and oral), 46% (23) took steroids (oral only), whereas 16% (8) recovered without steroids. The stage of AVN correlated with the severity of COVID-19 infection (p-value -0.038) and significant improvement in VAS and HHS after treatment in each stage. The mean follow-up was 9.79 months (6-19 months).

CONCLUSION

A low-dose steroid intake with moderate to severe COVID-19 infection produces an additive effect on the development of AVN hip. Most affected individuals were adult males, and stage II AVN was the most common, managed with bisphosphonates and core decompression for short intervals.