The study demonstrated that in ONFH (osteonecrosis of the femoral head) patients (particularly in ARCO stage III or size C disease), the modified trapdoor procedure is linked with superior clinical and radiographic results in comparison with the light bulb technique. In patients with postcollapse osteonecrosis, which tends to harm bone beneath the cartilage and devastate articular cartilage, this femoral head-preserving technique may delay hip arthroplasty in the majority of patients. This, in turn, eradicates the requirement for eventual arthroplasty in majority of the patients.

This prospective cohort study was carried out to examine radiological and clinical outcomes of autologous tricortical iliac block grafting through a window built at the femoral head without suturing the opened articular cartilage (also known as modified trapdoor procedure) for ONFH management.

From April 2009 to March 2012, this study was conducted and included a total of 59 consecutive ONFH participants (67 hips; 36 males and 23 females). Mean age of patients was 36.3 years. To examine hip function pre- and postoperatively, HHS (Harris hip scores) were utilized. To assess size, location, and ARCO (Association Research Circulation Osseous) stage of the lesion, MRI (magnetic resonance imaging), anteroposterior and frog-position X-rays were conducted.

Clinical and radiographic failure was measured. Matching of this group was done according to the ARCO stage, extent, location, etiology of the lesion, average age, gender, and preoperative HHS to a group of 59 subjects (67 hips) who were treated with the light bulb approach between March 2007 and April 2009.

The participants were followed for 91.2 ± 13.6 months. Mean HHS measured was 91.3 ± 4.5 in comparison with 83.1 ± 4.5 in the “light bulb” cohort at the 6-year follow-up examination as depicted in Table 1:

At the 6-year follow-up, for modified trapdoor procedures, around 5 hips (8.5%) were classified as clinical failure, and 3 hips underwent total hip arthroplasty; 7 hips were classified as (10.4%) radiographic failure.

The radiographic and clinical failure of the hips treated utilizing the femoral head-preserving technique was found to be remarkably lower in comparison with the hips treated utilizing the light bulb technique. Between the two groups, joint survival was not found to be considerably linked with the position of the femoral head lesion. However, superior results were witnessed in modified trapdoor procedures.

In patients with postcollapse osteonecrosis and large lesion, the modified trapdoor procedure is superior in comparison with the light bulb technique.