{'fraction_non_alphanumeric': 0.01981178801386825, 'fraction_numerical': 0.0, 'mean_word_length': 5.666666666666667, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Complications in primary total hip arthroplasty: avoidance and management: wear.

Many factors, including polyethylene processing, sterilization method, counterface material, femoral head size, femoral offset, acetabular component position, implant design, and patient activity level, affect the rate of wear in total hip arthroplasty. For patients with life expectancy that exceeds the longevity of the conventional implant materials, an alternative bearing surface (highly cross-linked polyethylene, metal-on-metal, or ceramic-on-ceramic) may be considered. Although laboratory wear tests with these materials are very favorable, clinical outcomes have not been clearly established. When osteolysis does develop in response to particulate debris, the location and progression of the lesions may be quite variable. Asymptomatic stable lesions can be followed clinically and radiographically while symptomatic or enlarging lesions or those that may compromise the integrity of the periprosthetic bone stock require surgery. If acetabular component revision is necessary and an adequate rim of host bone is maintained to support a revision acetabular component, defects can be filled with particulate bone graft. Large segmental defects generally require structural allografts. If the acetabular shell is well fixed in good position and the osteolytic defects are accessible, treatment with curettage and bone grafting of the lesions with liner revision is appropriate to avoid use of a structural allograft. Proximal femoral defects around a well-fixed stem can be managed in a similar manner with curettage and bone grafting. Distal lesions associated with risk of periprosthetic femur fracture or implant loosening require stem revision. Osteoclastic resportion of bone in response to particulate debris can be impaired with use of some drugs such as alendronate. However, the safety and efficacy of alendronate in the clinical management of osteolysis associated with total hip arthroplasty has not been established.