[Hip preservation experience of avascular necrosis of femoral head according to China-Japan Friendship Hospital classification].

OBJECTIVE: To 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).
METHODS: The 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.
RESULTS: According 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.
CONCLUSION: The staging treatment method for ANFH according to CJFH Classification has good short-term effectiveness. But the long-term effectiveness needs further follow-up.