Abstract

Background: Avascular necrosis of the femoral head (AVNFH) is a progressive and debilitating condition that predominantly affects young and middle-aged adults, often leading to femoral head collapse and the need for total hip arthroplasty. Although stem cell–based therapies combined with core decompression have shown encouraging results, the durability of a single stem cell application remains uncertain. This study evaluates the clinical and radiological outcomes of a structured stem cell reutilization approach over a two-year follow-up period in a single tertiary center.

Methods: This prospective single-center study was conducted at Al-Iraqi Hospital, Najaf, and included patients diagnosed with Steinberg stage I–III AVNFH. All patients underwent standard core decompression followed by intramedullary injection of autologous bone marrow mononuclear cells prepared using a simplified, non-Ficoll double-spin technique. Sequential stem cell reinjections were performed at 3 and 6 months. Clinical outcomes were assessed using the Visual Analog Scale (VAS) for pain and the Harris Hip Score (HHS) for function. Radiological evaluation was performed using serial MRI scans at baseline and during follow-up to assess lesion size, bone marrow edema, and structural progression.

Results: Significant and sustained improvement in both pain and hip function was observed throughout the follow-up period. Mean VAS scores showed a marked reduction, while HHS demonstrated substantial functional recovery at 24 months. MRI analysis revealed lesion regression or radiological stabilization in the majority of hips, particularly in early-stage disease. Disease progression and conversion to total hip arthroplasty were confined primarily to advanced stage III cases. No major procedure-related complications were recorded.

Conclusions: Sequential reutilization of autologous bone marrow–derived stem cells appear to enhance and prolong the therapeutic benefits of biological hip preservation in patients with early and mid-stage AVNFH. The approach is safe, feasible, and effective within a resource-limited clinical setting, and may reduce disease progression and delay the need for arthroplasty. These findings support the role of staged biological reinforcement as a promising strategy in the contemporary management of AVNFH.

Keywords: Avascular necrosis; Femoral head; Stem cell reutilization; Bone marrow mononuclear cells; Core decompression; Regenerative orthopedics; Hip preservation.