TKA術中ギャップ計測Knee-BalancerとSpacerの比較検討

抄録

Objective: We compared gap measurements using a knee balancer and a spacer block in total knee arthroplasty.
Methods: Between July 2008 and October 2010, 110 knees were investigated using a knee balancer with both 30 and 40 lbs tension in 92 patients (age range 47-91 years, mean 71.4 years). Seventy-four patients were women and 18 were men; 78 had osteoarthritis and 14 had rheumatoid arthritis. Between August 2009 and March 2011, 127 knees were measured using a spacer block in 95 patients (age range 47-88 years, mean 69.4 years). Seventy-eight patients were women and 17 were men; 81 had osteoarthritis, 11 had rheumatoid arthritis, and 3 had idiopathic osteonecrosis. After removal of all osteophytes and soft tissue release, we measured the extension gap (EG) and flexion gap (FG) with the posterior cruciate ligament retained.
Results: The average values of EG and FG, respectively, were 15.1±3.1 and 18.8±2.9 mm at 30 lbs balancer tension, and 16.8±3.2 and 20.2±3.1 mm at 40 lbs balancer tension. With the spacer block, the values were 16.9±3.1 and 18.8±2.5 mm, respectively. There was a significant difference (p < 0.05) between the 30 lbs balancer group and the spacer block group for EG, and between the 40 lbs balancer group and the spacer block group for FG.
Conclusion: These data suggest that the distraction force between the femur and the tibia using a spacer block was almost the same as that for a 40-lbs knee balancer for EG measurement and almost the same as that for a 30-lbs knee balancer for FG measurement.