Objective To analyze the similarities and differences of bone microstructure and apoptosis phenotype of lateral column, middle column, and medial column in type L2 and L3 osteonecrosis of the femoral head (ONFH) specimens classified by China-Japan Friendship Hospital (CJFH) classification, so as to carry out a quantitative study of ONFH “three-columns structure theory” and to provide research support for the treatment of ONFH by rotational osteotomy through the base of femoral neck. MethodsDiscarded femoral head specimens from 16 patients (16 hips) with CJFH type L2 and L3 ONFH undergone total hip arthroplasty between April 2020 and February 2021 were selected as the research objects. First, the “three-column structure” of the femoral head was three-dimensionally segmented by Micro-CT, and the bone volume to total volume (BV/TV), bone surface area to bone volume ratio (BS/BV), trabecular spacing/separation (Tb.Sp), trabecular thickness (Tb.Th), and trabecular number (Tb.N) in the lateral column, middle column, and medial column were analyzed to compare the similarities and differences of parameters related to bone mass and trabecular structure among the three columns. Then, the specimens were cut with a oscillating saw and made into paraffin sections for HE staining and immunohistochemical staining of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax). The differences of apoptosis phenotype between the three columns of ONFH samples of CJFH type L2 and L3 were evaluated by comparing the rate of empty lacunae and the rate of positive cells of immunohistochemical staining. ResultsThere were significant differences in BV/TV, Tb.Th, and Tb.N among the three columns of CJFH type L2 ONFH femoral head (P<0.05), with the largest in the medial column and the smallest in the lateral column; BS/BV and Tb.Sp of the lateral column were significantly greater than those of the medial column and middle column (P<0.05), no significant difference was found between the middle column and medial column (P>0.05). There was no significant difference in the bone parameters between the three columns of the CJFH type L3 ONFH femoral head (P>0.05). There was no significant difference in the rate of empty lacunae between the three columns of the CJFH type L2 and L3 ONFH femoral head (P>0.05). Immunohistochemical staining showed that a large number of tissue sections were detached, and only a small amount of non-specific staining was found in the sections without detachment, so the positive cell rate could not be calculated. Conclusion The middle and medial columns of the CJFH type L2 ONFH has better trabecular structures than the lateral column, and there is no significant difference in trabecular structures among the three columns of the CJFH type L3 ONFH.
Objective To explore the feasibility of virtual reality (VR) technology combined with reduction plasty of the femoral head in the treatment of coxa plana and evaluate its effectiveness. Methods Three patients with coxa plana were selected as the research objects between October 2018 and October 2020, all of them were male, aged 15-24 years. Preoperative surgical planning was performed using VR technology; 256 rows of CT data of hip joint were imported into software to generate three-dimensional (3D) imaging, simulate the surgical process, and determine the matching relationship between the femoral head and acetabulum. According to the preoperative planning, reduction plasty of the femoral head under surgical dislocation, relative lengthening of the femoral neck, and periacetabular osteotomy were performed. The reduction of osteotomy size of femoral head and rotation angle of acetabulum were confirmed by C-arm fluoroscopy. The healing of the osteotomy were assessed by radiological examination after operation. The Harris score of hip function and visual analogue scale (VAS) score were recorded before and after operation. The femoral head roundness index, center-edge (CE) angle, and femoral head coverage were measured by X-ray films. ResultsThree operations were completed successfully, and the operation time was 460, 450, and 435 minutes, and the intraoperative blood loss was 733, 716, and 829 mL, respectively. All patients were infused with 3 U suspension oligoleucocyte and 300 mL frozen virus inactivated plasma after operation. No postoperative complication occurred, such as infection and deep vein thrombosis. Three patients were followed up 25, 30, and 15 months, respectively. CT showed good healing of the osteotomy at 3 months after operation. The VAS score and Harris score at 12 months after operation and at last follow-up, as well as the femoral head rounding index, hip CE angle, and femoral head coverage at 12 months after operation significantly improved when compared with those before operation; the hip function was evaluated by the Harris score at 12 months after operation, and all three patients were good. ConclusionVR technology combined with reduction plasty of the femoral head can achieve satisfactory short-term effectiveness in the treatment of coxa plana.