Geometric analysis of an expandable reamer for treatment of avascular necrosis of the femoral head

Abstract

"Advanced core decompression" (ACD) is a treatment option for osteonecrosis of the femoral head (ONFH) that aims at complete removal of the necrotic tissue using a percutaneous expandable reamer and refilling of the head with an osteoconductive bone-graft substitute. The objective of this study was to evaluate if the success of ACD depends on the amount of necrotic tissue remaining after the procedure and how efficiently the necrotic tissue can be removed with the current reamer. Three-dimensional models of proximal femora including ONFH were generated from the preoperative MRIs of 50 patients who underwent ACD. Best-case removal was calculated by geometrical analysis. In 28 of 50 cases, postoperative MRI was used to determine how much necrotic tissue had been removed. Prognostic values and correlations were evaluated in order to assess success or failure of the treatment. The amount of preoperative and remaining necrosis correlates significantly with treatment failure. The larger both volumes are, the more likely it is that treatment will fail. In patients with remaining necrosis of less than 1000 mm(3), no treatment failure was observed. The amount of necrosis actually removed differed significantly from the amount calculated as the best possible result. Simulation of the removal procedure showed that complete removal is not possible. These results led to the conclusion that the success of ACD depends on the amount of necrotic tissue remaining in the femoral head after the procedure. Modifications to the instrument are necessary to increase the amount of necrotic tissue that can be removed.

Investigating Clinical Failure of Bone Grafting through a Window at the Femoral Head Neck Junction Surgery for the Treatment of Osteonecrosis of the Femoral Head

“…Numerous studies have reported that the amount of the necrosis is an important factor affecting the efficacy of hip-saving surgery, and the larger the necrotic area, the higher the rate of surgical failure [ 13 – 19 ]. Landgraeber et al [ 20 ] reported that the amount of preoperative necrosis correlates significantly with treatment failure. Patients who were treated with advanced core decompression with a preoperative necrotic volume of less than 2500 mm3 have a relatively low failure rate of 13% in comparison to patients with a larger preoperative necrotic volume.…”

Modified technique of percutaneous core decompression with flexible reamers and percutaneous iliac bone graft harvesting for treatment of femoral head osteonecrosis

“…Core decompression combined with bone grafting (with or without adjuvants) as a joint-preserving surgical treatment has been widely recognized before [3,16,26,27,28] . In recent years, studies also showed that patients with ARCO classification system stage II treated by Core decompression combined with autologous bone and BMA had good outcomes [2Other studies have already shown the usefulness of eliminating the necrotic bone and structural support by the adjuvant substances in the treatment of early ANFH ies [3,22,30] . Arlet and Ficat first introduced core decompression in 1964 and they reported "good to very good results" in 90% of these hips on clinical evaluation and in 79% on radiographic evaluation [31] .…”

Multiple drilling is not effective in reducing the rate of conversion to Total hip Arthroplasty in early-stage nontraumatic osteonecrosis of the femoral head: a case-control comparative study with a natural course

“…Won Seok et al reported similar results: the survival rates of small necrotic lesions (100%) and medium-sized lesions (84.1%) were significantly higher than those of large necrotic lesions (53.8%) [ 6 ]. Stefan et al reported that no treatment failure was observed in patients with remaining necrosis of less than 1000 mm 3 at a mean follow-up of 33 months [ 35 ]. One reason for this association may be intuitive as patients with larger necrotic lesion in subchondral lesions may have less mechanical support of the femoral head and a higher risk of hip collapse.…”