ObjectiveTo sum up staging treatment experiences of hip preservation for avascular necrosis of the femoral head (ANFH) according to China-Japan Friendship Hospital Classification (CJFH Classification).MethodsThe literature about hip preservation of ANFH was extensively reviewed, and a staging treatment method for ANFH was set up base on CJFH Classification and the 28 years of clinical experience in this research group.ResultsAccording to CJFH Classification, the ANFH can be rated as types M, C, and L. And the type L is rated as L1, L2, and L3 subtypes. The staging treatment method for ANFH based on CJFH Classification is set up. Conservative treatment was selected for CJFH-M patients because the necrotic area is small and in the medial non-weight-bearing area. Minimally invasive sequestrum clearance, impacting bone graft, and supporting allogenic fibular graft is selected for CJFH-C patients because the necrotic area is also small and in the lateral non-weight-bearing area. If patients are in CJFH-L1, normal bone area is less than 1/3 on hip abduction radiograph, the sequestrum clearance and impacting bone graft via surgical hip dislocation approach can be selected. If patients are in CJFH-L1, normal bone area is more than 1/3 on hip abduction radiograph, the transtrochanteric curved varus osteotomy can be selected. The rotational osteotomy on the base of femoral neck via surgical hip dislocation approach is for CJFH-L2 patients. Total hip arthroplasty via direct anterior approach is for CJFH-L3 patients.ConclusionThe staging treatment method for ANFH according to CJFH Classification has good short-term effectiveness. But the long-term effectiveness needs further follow-up.
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.