Distribution of early- versus late-stage ONFH in core decompression cases at a tertiary center: does presenting symptomatology affect conversion to total hip replacement?

BACKGROUND

Core decompression (CD) is a common joint-preserving procedure for early-stage osteonecrosis of the femoral head (ONFH). Although disease stage is a known predictor of outcomes, the role of preoperative symptoms and risk factors remains unclear, especially in asymptomatic ONFH patients incidentally detected via MRI.

METHODS

We retrospectively analyzed 176 patients (222 hips) who underwent CD from 2010 to 2023 with a minimum follow-up of 24 months. Inclusion criteria included ONFH at ARCO stages I to III and preoperative MRI sufficient for staging. The primary outcome was hip joint survival, defined as avoidance of total hip arthroplasty (THA). Kaplan-Meier survival analysis and binary logistic regression were employed to assess associations between ARCO stage, symptoms, risk factors, and treatment outcomes.

RESULTS

The ARCO stage at the time of CD was significantly associated with hip survival and conversion to THA (p < 0.05). Early-stage hips demonstrated higher survival rates compared to late-stage hips. Neither preoperative symptom status nor common risk factors such as steroid use, alcohol consumption, or smoking were significantly related to CD success. Notably, asymptomatic patients exhibited comparable outcomes to symptomatic patients following CD.

CONCLUSIONS

Post-CD outcomes are stage-dependent. Symptom presence does not significantly affect prognosis. These findings support early intervention even in asymptomatic ONFH patients with early-stage disease.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.