Improved single-limb balance after total knee arthroplasty.

Purpose: Unsteady ambulation shortly after total knee arthroplasty (TKA) may cause falling. Postural sway may predict the risk of falling. This prospective single-blinded observational study therefore evaluated the effects of TKA on single-limb standing balance (SLSB) and factors related to change in SLSB.

Methods: Patients with varus deformity and medial compartment degeneration were evaluated between September and December 2010. The Western Ontario and McMaster Universities Osteoarthritis Index and Kellgren/Lawrence scale were assessed, as were varus angle, number of painful knees, isometric peak torque of the quadriceps femoris, balance index of double limbs, and postural sway of single limbs.

Results: Twelve patients were enrolled and 11 were analysed. The mean ± SD postural sway of single limbs (i.e., SLSB) was reduced significantly after TKA, from 30.3 ± 20.8 cm to 18.5 ± 9.3 cm (p = 0.02). Amelioration was in proportion to pre-operative postural sway (β = 0.92).

Conclusions: SLSB in patients with varus knees with osteoarthritis was improved significantly 11 days after TKA. Poorer pre-operative SLSB was associated with better post-operative SLSB. TKA may be useful for the immediate reduction of falling in patients with osteoarthritis.