Total knee replacement with interlocking stems - A preliminary report

total knee replacements or primary total knee replacements with large amoun ts of bone loss frequently require long-stemmed prostheses to stabilize the components. The hypothesis of the current study was that long-stemmed pros theses can be fixed with interlocking screws, provide a successful outcome, avoid extensive stress-shielding, and allow easy revision in the future. T en patients with a minimum 2-year followup were studied. Outcomes were stud ied preoperatively and postoperatively using the Short Form-12 questionnair es, physical examinations, and radiographs. Complications were recorded. Ab ility to do activities of daily living, strenuous work, and sedentary work were recorded on a 10-point analog scale. Results indicated that 80% of ste ms well-fixed as shown on serial radiographs, functional outcome scores pos toperatively improved significantly from preoperatively, pain was improved significantly, and positive bone remodeling without stress-shielding was se en in 80% of patients, but 20% had significant stress-shielding in the meta physis. Complications included two periprosthetic fractures for which the p atients did not require revision surgery, and one infection. Long-stemmed t otal knee components with interlocking fixation seem to be a reasonable alt ernative when large bone defects exist in the femur or tibia.