The Long-Term Results of Hip Arthroplasty in Patients with Proximal Femur Tumors

Relevance. The development of the modern principles of combined tumor treatment has significantly improved the survival of the patients. For these patients, the organ-preserving surgerybecomes now the mainstream tactics. For the restoration of the lower limb support ability and the hip function, the hip arthroplasty is now the most used type of surgery. Purpose of the study. The purpose of this work was to evaluate the long-term results of hip arthroplasty in the patients with extensive proximal femur defects caused by tumors and tumor-like lesions. Materials and Methods. The data on 126 patients with proximal femur tumors, undergone the surgical treatment in 2000–2013, were collected and summarized. The average age of the patients was 53.8 years (26–74), 94 women (74.6%), and 32 men (25.4%). There were 16 primary malignant bone tumors (12.7%), 10 benign aggressive (7.9%); 92 metastatic (73%), and 8 tumor-like lesions (6.4%). The average follow-up after the surgery was 72.6 months. The complications classification and analysis were performed according to the criteria of the International Society of Limb Salvage 2014 (ISOLS 2014). For the assessment of the functional result, patients were divided into 4 groups. In this context, the following indicators were taken into account: whether the acetabular component or the bipolar head were used, and the method of the soft tissues fixation to the femoral component of the endoprosthesis. Functional outcome was evaluated using the international Musculoskeletal Tumor Society (MSTS) scoring system at 3, 6, and 12 months. Results. The total number of complications, identified during the observation period from 2000 to 2018, was 26 (20.6%). The oncological complications, represented by local recurrence, were detected on average after 11.5 months. The total number of local recurrences is 6 (4.7%) which amounted to 23% in the structure of all complications. Dislocations of the endoprosthesis became the most frequent complication — 13 (10.3%) observations, 50% in the structure of all complications. Only one patient with aseptic instability of the femoral component was identified over the entire follow-up period. There were 4 (3.1%) patients with complications due to the destruction of metal constructions. All of them had an endoprosthesis stem fracture. The average period of onset of these complications was 122.5 months. Prosthetic joint infection was observed in 2 (1.6%) patients (7.2% of all complications), on the 14th and 31st days. The patient with the latter onset of infection underwent a twostaged revision arthroplasty. Functional result by the MSTS scale: 3 months — 74.8%, 6 months — 79%, 12 months 81.8%. In the patients under investigation, 5-, 10-, and 15-year survival for aggressive benign tumors and tumorlike lesions was 95%, 84%, 62%; for malignant primary tumors — 88%, 65%, 24%; for secondary bone lesions 55%, 43%, 12%, respectively. Conclusion. The use of a bipolar head made it possible to reduce the likelihood of an endoprosthesis dislocation. The fixation of the preserved muscle elements with a polymer mesh made it possible to obtain the best functional result already in the early postoperative period.

hip arthroplasty, bone tumors, endoprosthesis dislocation, functional result of the oncological arthroplasty, polymer meshes