Clinical and gait-analytical results of the modified Evans tenodesis in chronic fibulotalar ligament instability

The present paper describes the medium-term results (mean follow-up period 3.01 years) achieved after surgical stabilisation of 79 patients using modi fied Evans tenodesis. The follow-up examination included a questionnaire fo r rating the subjective sense of stability, a clinical examination, stress X-rays, a modified 100-point score according to Zwipp, and kinetic gait ana lysis. Although joint instability was significantly improved in the radiolo gical stress images, only 73.4% of the patients subjectively rated the stab ility achieved as excellent or good, compared with satisfactory in 22%, and even poor in 3.8%. In the overall result of the 100-point score, 51.9% of the patients achieved a very good, 35.4% a good, 11.4% a satisfactory, and 1.3% a poor result. Radiologically, an increase in the rate of arthrosis wa s verified in 17.4%. Significant deteriorations in mobility were observed f or the supination. The kinetic gait analysis revealed statistically signifi cant differences compared with the non-operated side for step length (P<0.0 5), relative step length (P<0.05), and in the symmetry of heel-to-toe movem ent (P<0.005). The modified Evans repair can restore the mechanical stabili ty of the ankle, but it leads to impaired kinematics of the ankle, with sub jective and functional restrictions and radiologically detectable degenerat ive changes. For this reason, modified Evans tenodesis should only be per f ormed if anatomically orientated stabilisation operations are not possible.