Ultrasonographic measurement of the distal femoral cartilage thickness in patients with unilateral transtibial amputation

Background: Lower limb amputation sometimes predisposes to degenerative secondary disorders. Objectives: To evaluate the distal femoral cartilage thicknesses of patients with unilateral transtibial amputations using ultrasound and to investigate the relationship between cartilage thickness and disease-related parameters. Study Design: Cross-sectional study. Methods: Twenty-four unilateral transtibial amputees (mean age: 46.4 +/- 8.5 years, range: 28-60 years) were evaluated. Duration of prosthesis use (years) and daily walking time with prosthesis (hours) were recorded. Functional status was assessed by gate velocity (m/s), and 6-min walking distance (m) with prosthesis. Ultrasound was used to measure distal femoral cartilage thicknesses bilaterally at medial/lateral condyles and the intercondylar areas. The percentages of cartilage loss (of the amputee-side in comparison with the nonamputee-side) were calculated. Results: Compared to the nonamputee-sides, distal femoral cartilage was significantly thinner at lateral condyles and the intercondylar areas on the amputee-sides (p < 0.05). Significant positive correlations were detected between the percentage of cartilage loss (at all three sites of measurement) and gate velocity, 6-min walking distance, and daily walking time with prosthesis (all p < 0.05). Conclusions: Future prospective controlled studies are warranted to determine the principles of optimum prosthetic use regarding its possible effects on the femoral cartilage of amputee patients.