Less valgus alignment in total knee arthroplasty for the varus knee

Constitutional varus of the leg is well recognizable anatomically. Moreland1] studied long standing radiographs of normal males with a range of varus from 2.6-3° in the proximal tibia. Victor et al. 2] reported constitution varus of 3 degree in 32% men, 17% women. The authors routine technique during total knee arthroplasty (TKA) is to cut the distal femur at 5° valgus and the tibia at neutral for the valgus leg and cut the distal femur at 5° valgus and the tibia 2° varus for varus aligned limbs. 127 consecutive long standing knee radiographs were not retrospectively studied pre and post operatively with 2 year minimum follow up. Average age was 68 years (range 51-90). Average weight was 215 lbs (range 110 – 333). Average tourniquet time was 32 minutes for all patients prior to closure.For the varus group (72 knees), average pre-op tibial femoral alignment was 3.3° varus (range 0-13°). Post-op tibial femoral alignment was 1.2° valgus (range 1° varus - 5° valgus) with the mechanical axis falling into the medial compartment in all patients. Average pre-op knee score was 88 and post-op was 180 at minimum of 2 years.For the valgus group (55 knees), average pre-op tibial femoral alignment was 7.5° (range 2°-24°) valgus. Average post-op tibial femoral alignment was 3.8° (range 1°-10°) valgus. Average pre-op knee score was 107 and post-op was 182 at minimum of 2 years. The authors agree with aiming for valgus alignment for the classic valgus leg (mechanical axis centered on hip, knee, ankle) and less valgus alignment for the varus knee (mechanical axis into the medial compartment). Following the patients anatomy eliminates the need for major soft tissue releases while still avoiding “malalignment”. No special soft tissue releases were required in any patient with pre-op varus or valgus alignment. The clinical outcome is not effected by leaving pre-op varus aligned extremities in less valgus with their TKA’s.