Introduction: Transtrochanteric anterior rotational osteotomy (ARO) is an established joint-preserving surgery for collapsed osteonecrosis of the femoral head (ONFH) in which the collapsed necrotic lesion is rotated ante-riorly. Recently, preoperative collapse of more than 2.98mm was reported to be the most influential factor for progressive collapse of the anteriorly transposed necrotic lesion after ARO, the main cause of secondary osteoarthritic changes and clinical failure. We attempted to prevent progressive collapse with re-sphericalization of the collapsed femoral head using calcium phosphate cement (CPC) filling in conjunction with ARO. Materials and Methods: Between May 2015 and April 2018, five consecutive hips with ONFH, femoral head collapse of ≥3mm, and one-third or more of the posterior region of the femoral head intact, were prospectively recruited for re-sphericalization with ARO. This report describes intraoperative surgical techniques focusing on re-sphericalization of the collapsed femoral head using CPC and short-term effects of this additional procedure on progressive collapse of the transposed necrotic lesion, defined as ≥2mm progression on lateral radiographs. Results: After anterior rotation of the proximal fragment, followed by fixation of the transtrochanteric osteotomy site, a 5mm fenestration was made in the collapsed region of the anterior femoral head cartilage, through which the collapsed surface was carefully lifted with an elevatrium. Subsequently, CPC paste was injected into the lifted subchondral space with a small needle. After CPC paste injection, the femoral head was maintained at 40°C for 10 minutes to promote solidification of the CPC paste. With the re-sphericalization method, the mean level of collapse decreased from 4.1mm before surgery to 2.0mm after surgery. Subsequently, progressive collapse of the transposed necrotic lesion was confirmed in two hips. One of these hips had a deep infection that required complete curettage of CPC three weeks after the initial surgery. All hip joints have been preserved without conversion to prosthesis during a mean follow up of 2.1 years. Conclusion: A joint-preserving procedure for ONFH with severe collapse remains a challenging problem for surgeons. When ARO is indicated based on one-third or more of the posterior region of the femoral head being intact, the current re-sphericalization method could be worth considering as an additional procedure in cases with severe collapse.
|Number of pages||4|
|Journal||Surgical technology international|
|Publication status||Published - May 2020|
All Science Journal Classification (ASJC) codes