Screw osteolysis in the cementless anatomic modular knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Radiology

Background:

• Cementless Anatomic Modular Knee arthroplasty is a common procedure.
• Screw fixation is frequently used in knee arthroplasty.
• Osteolysis, or bone loss, is a potential complication of joint implants.

Purpose of the Study:

• To investigate the natural history of screw-associated osteolysis.
• To determine the incidence and progression of osteolysis in cementless Anatomic Modular Knee arthroplasty.
• To identify risk factors and outcomes associated with osteolysis.

Main Methods:

• Prospective follow-up of a cohort of 230 patients (280 arthroplasties) who underwent cementless Anatomic Modular Knee arthroplasty.
• Initial fluoroscopically guided radiographs in 1993 to detect occult osteolysis.
• Periodic reassessment to monitor for new or progressive screw-associated osteolysis.
• Radiographic grading of osteolysis severity.

Main Results:

• At early follow-up, 34% of knees showed osteolysis.
• Osteolysis progressed in all groups, with 60 additional knees developing osteolysis.
• At intermediate follow-up, 55% of knees exhibited radiographic evidence of osteolysis.
• Osteolysis progressed to a higher grade in a significant percentage of patients.
• 23% of arthroplasties required revision surgery due to osteolysis.

Conclusions:

• Screw-associated osteolysis is a common and progressive complication in cementless Anatomic Modular Knee arthroplasty.
• Regular periodic radiographic evaluation is recommended for early recognition and management.
• Further research may explore strategies to mitigate screw-associated osteolysis.