ObjectiveTo explore the feasibility and effectiveness of the modified transtrochanteric curved varus osteotomy in the treatment of osteonecrosis of the femoral head (ONFH), clarify the key points of the operation, and then explore the effectiveness of modified transtrochanteric curved varus osteotomy in the treatment of ONFH assisted by virtual reality (VR) technology. MethodsA 70-year-old adult female cadaver without formaldehyde fixation was taken. It was confirmed by anatomical study and simulated operation that the modified transtrochanteric curved varus osteotomy was suitable for type C1 (patients with involvement of the lateral column of the femoral head but partial integrity) classified by the Japanese Osteonecrosis Investigation Committee (JIC). Between October 2018 and August 2020, 11 patients (17 hips) with ONFH who met the selection criteria were treated with modified transtrochanteric curved varus osteotomy. VR technology was used to simulate varus osteotomy before operation to predict the angle of valgus of lower limbs and pronation of femoral head. Osteotomy, valgus, and pronation were performed according to the results of preoperative planning. After operation, X-ray films were used to evaluate the changes of varus and neck-shaft angle after VR assisted surgery, and Harris score was used to evaluate the hip function. ResultsThe anteroposterior pelvic X-ray film was rechecked at 2 days after operation, of which 3 hips were consistent with the planned varus angle of VR preoperative planning, and the error value of varus angle of the remaining 14 hips was 1°-4°. The difference between VR preoperative planning and 2 days after operation was 6°-16°. All 11 patients were followed up 11-28 months, with an average of 19.2 months. All incisions healed by first intension. During the follow-up, 1 case (1 hip) developed greater trochanter fracture at 2 months after operation and was treated with open reduction and plate and screw internal fixation; 1 case (1 hip) had delayed healing at osteotomy at 4 months after operation and healed at 3 months after local injection of platelet rich plasma and oral supplementation of kidney blood-strengthening soup. At last follow-up, 17 hip osteotomies healed. The Harris score was 84.0±5.6, which was significantly higher than that before operation (57.2±5.5) (t=–14.107, P=0.000); hip function was excellent in 2 hips, good in 13 hips, and fair in 2 hips. ConclusionThe modified transtrochanteric curved varus osteotomy for the treatment of ONFH is theoretically feasible, and the short-term effectiveness of this operation combined with VR technology is satisfactory.
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.