The proximal femur is the second most common site for primary tumors of bone. Resection of the proximal femur often leads to hip instability, which is caused by a decrease in the strength of the hip’s previously strong joint capsule and a decrease in the strength of the hip’s abductor muscles. However, despite the higher compressive stress on the proximal femur, there is a lower rate of complications with either metal or allograft bone reconstruction compared to the failure rate of periprosthetic reconstruction around the knee. Monoprosthesis and composite prosthesis are the two most commonly used reconstruction methods in this area. And the latter has a better functional prognosis. The common complications of this part of the prosthesis include dislocation and loosening of the prosthesis. Reconstruction of the joint capsule and abductor muscles can effectively improve the stability of the hip joint and improve the postoperative function of the patient. 1.Artificial prosthesis reconstruction After resection of the tumor of the upper femur, artificial prosthesis or artificial prosthesis allograft bone complex reconstruction is performed, and the most important is the reconstruction of the abductor muscle. This part is limb-preserving surgery and does not increase the local recurrence rate. For upper femoral prosthetic reconstruction, dislocation, aseptic loosening and polyethylene liner wear are the most common prosthesis-related complications. 20% prosthetic dislocation rate was reported by Grimer et al. Ilyas et al. reviewed 15 patients who underwent biotype Kotz proximal femoral prosthetic reconstruction with a mean follow-up of 6.7 months, one case of aseptic loosening, two cases of infection and a 20% dislocation rate. Malo et al. concluded that patient age, presence of pathologic fracture, and type of prosthesis were the main factors affecting the prognosis of the prosthesis in a study of 31 non-cemented hinged tumor knees and 25 cemented grouped tumor rotating hinged knees with reconstructed follow-up. Eckardt reported the results of 46 postoperative follow-ups of tumor-based prostheses of the upper femur: the 5-year survival rate of patients was 57% and the prosthesis survival rate was 68%. malawer and Chou50 reported 7 cases of upper femoral and double-action hip replacements. 3 cases (43%) had recurrence, 1 case was treated with amputation, and there were no revision cases at 5 years of postoperative follow-up. unwin et al. reported 263 cases of upper femoral prosthesis replacement, with an amputation rate of 6.5% and a revision rate of 6.1%, and a 20-year survival rate of >80%. Grimer performed prosthesis replacement in 41 cases of primary malignancy of the upper femoral segment, with a mean follow-up of 9 years and an overall survival rate of 65% at 10 years and 48% at 20 years. The local recurrence rate was 28%, and recurrence and death occurred in 5 of 9 osteosarcomas. 7 of 31 chondrosarcomas recurred (23%). The overall amputation rate was 13%. 1 of the Grimer prosthesis revision procedures was due to recurrence, 2 to recurrent dislocation, and 6 to aseptic loosening. There was no significant difference in postoperative function by whether the acetabulum was treated, i.e., total versus double-acting hip. Dislocation was the most common complication, with a dislocation rate of 11-15%. Acetabular molding is not required when applying a double-action artificial hip for upper femoral reconstruction, and some long-term follow-up results have yielded the same conclusion. The hip capsule has been routinely preserved, the hip joint strengthened, and local muscle reconstruction performed to enhance hip stability, and preserving the hip capsule did not increase the recurrence rate of the tumor. bickel et al. reported a mean follow-up of 80 months after bimanual joint and hip capsule reconstruction in 57 patients with bone tumors of the proximal femur. no patient required a repeat acetabularplasty, and only one case of dislocation occurred. There were no cases of local recurrence of the joint capsule. The rate of acetabular loosening after upper femoral prosthesis replacement was higher than that of the femoral prosthesis. The loosening rate was higher in the normal total hip with a 32-mm diameter head, and Carter used a larger size artificial femoral head to reduce the loosening rate. The loosening rate of upper femoral prosthesis reported in different literature varies from 0-46%. malkani et al. applied tumor type prosthesis to reconstruct non-tumor type lesion cases with 64% prosthesis intact rate at 12 years. morris et al. reported 31 cases of biologic upper femoral and double movable head artificial hip replacement with 8 years of follow-up and no revision cases. In most studies, dislocation was the most common prosthetic complication, with rates ranging from 2%-20%. The rate of dislocation is twice as high as that after normal hip arthroplasty and may be due to weaker abductor muscles. 6 of the 41 cases of superior femoral segment reported by Carter (11%) required revision. The incidence of prosthetic fracture has been reported in the literature as 1-4%. This rate will decrease as prosthesis design improves and prosthetic materials are updated over time. In patients with superior femoral prosthetic reconstruction, there is no significant osteogenesis in the posterior medial cortex where the stress is more concentrated, but instead there is significant osteoporosis in the anterolateral aspect due to stress masking. The upper femoral segment can also be reconstructed with allograft bone grafts or allograft bone prosthesis complexes. The advantage of using allograft bone is that it allows reconstruction of the tendon ligament stop on the greater trochanter, which theoretically leads to better hip function. The healing between the allograft and the host bone also provides a more durable biological fixation. It is also possible to select the right size and shape of allograft bone for reconstruction.