Kubo Yusuke, Motomura Goro, Ikemura Satoshi, Hatanaka Hiroyuki, Utsunomiya Takeshi, Hamai Satoshi, Fujii Masanori, Fukushi Jun-Ichi, Nakashima Yasuharu
Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
J Orthop Sci. 2020 Jan;25(1):145-151. doi: 10.1016/j.jos.2019.02.014. Epub 2019 Mar 7.
Anterior localization of the necrotic lesion was recently proposed as an important factor for the occurrence of collapse even in medially located osteonecrosis of the femoral head (ONFH). We examined the effects of the anterior boundary of the necrotic lesion on progressive collapse after varus osteotomy for ONFH.
We reviewed the outcomes of 31 hips in 27 patients with ONFH treated by transtrochanteric curved varus osteotomy (CVO) from 2000 to 2012 with a mean follow-up of 10.5 years. The occurrence of progressive collapse of the anterior necrotic lesion was defined as the presence of ≥2 mm collapse using follow-up lateral radiographs. Postoperative osteoarthritic change was defined as ≥1 mm progression of joint space narrowing on follow-up radiographs. The location of the anterior boundary of the necrotic lesion was assessed using the anterior necrotic angle (the angle between the midline of the femoral neck shaft and the line passing from the femoral head center to the anterior boundary of the necrotic lesion on a mid-slice oblique magnetic resonance image).
All hips had a postoperative intact ratio of ≥34% (percentage of the transposed intact articular surface of the femoral head to the weight-bearing area of the acetabulum after femoral osteotomy). Progressive collapse of the anterior necrotic lesion was seen in five hips (16%) during a mean of 2.2 years after CVO. Of these, four hips (80%) proceeded to develop osteoarthritic change at an average of 4.3 years after the collapse. Multivariate analysis revealed that the anterior necrotic angle was independently associated with progressive collapse of the anterior necrotic lesion as well as the postoperative intact ratio.
This study suggests that hips with anterior localization of the necrotic lesion have a possible risk of progressive collapse of the anterior necrotic lesion after CVO, which can frequently lead to subsequent osteoarthritic change.
坏死病灶的前侧定位最近被认为是股骨头坏死（ONFH）塌陷发生的一个重要因素，即使是位于股骨头内侧的骨坏死。我们研究了坏死病灶的前边界对ONFH内翻截骨术后渐进性塌陷的影响。
我们回顾了2000年至2012年间27例ONFH患者接受经转子弧形内翻截骨术（CVO）治疗的31个髋关节的结果，平均随访10.5年。使用随访时的侧位X线片，将前侧坏死病灶的渐进性塌陷定义为塌陷≥2毫米。术后骨关节炎改变定义为随访X线片上关节间隙狭窄进展≥1毫米。使用前侧坏死角（股骨颈中轴线与在中间层面斜位磁共振图像上从股骨头中心到坏死病灶前边界的连线之间的夹角）评估坏死病灶前边界的位置。
所有髋关节术后完整率均≥34%（股骨截骨术后股骨头移位的完整关节面占髋臼负重区的百分比）。在CVO术后平均2.2年期间，5个髋关节（16%）出现了前侧坏死病灶的渐进性塌陷。其中，4个髋关节（80%）在塌陷后平均4.3年发展为骨关节炎改变。多变量分析显示，前侧坏死角与前侧坏死病灶的渐进性塌陷以及术后完整率独立相关。
本研究表明，坏死病灶位于前侧的髋关节在CVO术后有前侧坏死病灶渐进性塌陷的潜在风险，这常可导致随后的骨关节炎改变。
