Total knee arthroplasty in the elderly. Is there an age limit?

The goal of this study was to compare the results of the total knee arthroplasty (TKA) in 2 study groups only differing by age. We have analyzed 218 TKA cases (138 women and 80 men) with at least 2 years follow-up. Mean age was 70 years (SD, 7.38 years; range, 43 to 98 years). An age cutoff point at 75 years defined the 2 study groups: 167 cases younger than 75 years and 51 older. Results were evaluated using the Hospital for Special Surgery Score. Mean score was raised from 53.43 (SD, 9.186) preoperatively to 85.57 (SD, 10.763) in 2 years follow-up (P < .001). The final score did not show significant differences between both groups (86.11 for the younger group and 83.8 for the older group). Differences in pain on walking, pain at rest, walk, range of motion, climbing stairs, transfer, muscle strength, or instability were not found between the patients younger and older than 75 years. We did not find any differences in TKA, functional score, or pain between the 2 studied groups.

Measurement of bone mineral density is possible with standard radiographs: a study involving total knee replacement.

BACKGROUND: Measured bone density correlates well with the mechanical properties of the bone. Our objective was to evaluate optical densitometry as a method of measuring the periprosthetic bone density of the tibial platform in total knee replacement using serial dual-energy X-ray absorptiometry (DXA) as the reference test. METHODS: 30 patients who underwent a cemented total knee replacement were followed up for over 2 years. Standard radiographs of the knee were obtained at 12 and 24 months. These were photographed with a digital camera and enhanced with image processing software. A DXA scan was performed at the same time as the reference method. 3 regions of interest were defined under the tibial plateau (medial, lateral and stem positions). RESULTS: After 24 months of follow-up there was a significant decrease in density in the 3 regions, both with the optical and DXA methods. The concordance between methods was studied using Bland and Altman plots, Cronbach's alpha and intraclass correlation coefficients resulted in values from 0.72 to 0.87, depending on the region and the follow-up time. INTERPRETATION: Quantification of optical density values with a standardized measurement system on conventional radiographs is a reliable and efficient method of determining the bone mineral density.