Pericollapse Stage of Osteonecrosis of the Femoral Head: A Last Chance for Joint Preservation

Zhang, Qing-Yu; Li, Zi-Rong; Gao, Fu-Qiang; Sun, Wei

If left untreated, almost all symptomatic ONFH will progress to collapse and eventually disabling arthritis that requires hip arthroplasty; however, to date, for the intervention concerning asymptomatic ONFH, there is still no consensus. [10, 39, [47] [48] [49] The Chinese guideline for the diagnosis and treatment of ONFH recommends that the same principles should be applied to both symptomatic and silent hips; namely, only those patients with Stage I/II M type ONFH could wait for spontaneous repair with mere follow-up. [2] However, Mont et al. [3] advocated no more than observation for asymptomatic diseases. Given that the principle for the treatment of early-stage ONFH is to preserve one's natural joints, the therapeutic regimen for early-stage ONFH should be decided by classification, stages, and risk factors rather than symptoms [ Figure 4 ]. Any lesions susceptible to collapse need to be managed as soon as possible to regain structural stability of the femoral head and therefore halt the ongoing progression. [2, 46] Currently, joint-preserving techniques for pericollapse and postcollapse ONFH mainly include CD (normally combined with bone grafting), femoral osteotomy, nonvascularized bone grafting (NVBG), and vascularized bone grafting (VBG), with many studies showing successful outcomes at medium-term and long-term follow-up periods. [3, 49] Core decompression CD as well as the modified multiple percutaneous drilling procedure are the most commonly performed joint-preserving procedures, with the tenet of reducing intraosseous pressure and enhancing blood flow in the necrotic area. [3] Such techniques are mainly indicated in the treatment of small-to-medium-sized (<15% of the femoral head or a Kerboul angle <200%) ARCO Stage I/II lesions while the survivorship of lesions in the postcollapse stage (Ficat III) is only 23-35% in published studies. [50, 51] For lesions in the pericollapse and postcollapse stages, CD combined with bone grafting is normally applied. [41, 51]