KINEMATIC AND DYNAMIC GAIT ANALYSIS BEFORE AND AFTER SALTO TOTAL ANKLE ARTHROPLASTY

Abstract

Purpose of the study: The aim of this study was to analyze the mechanical function of the ankle after implantation of a total ankle arthroplasty. Gait analysis included kinematic and dynamic parameters of the lower limbs before and after prosthesis implantation in comparison with ankle fusion.

Material and methods: This prospective non-randomized study included three cohorts of patients. The first cohort included 12 patients presenting osteoarthritic lesions of the ankle requiring total ankle arthroplasty; these 12 patients were reviewed six months postoperatively and for six of them twelve months postoperatively. The second cohort was composed of 12 patients reviewed twelve months after tibiotalar arthrodesis. The third cohort was composed of 12 healthy volunteers who participated in the same study protocol. The gait analysis was conducted with the Motion Analysis optoelectronic system. Parameters recorded were: self-selected speed, fastest speed, stride rate, step length, stride symmetry and length, symmetry of floor contact, and symmetry of toe lift-off. In addition, patients participated in specific tests to step over an obstacle and go up and down stairs.

Results: Gail was slower an asymmetrical in patients with ankle fusion. Fusion enabled good recovery of gait speed but at the cost of imbalanced weight-bearing times and asymmetrical toe lift-off. Total ankle arthrodesis provided little improvement in gait speed but enabled progressive and persistent recovery of symmetrical gait.

Discussion: It is well established that an ankle prosthesis improved joint force and motion in comparison with the osteoarthritic ankle. Fusion provides good clinical and kinetic results but at the const of compensation by the joints above and below the ankle. Few studies have examined gait symmetry which in our opinion would be a good criterion for evaluating the quality of gait.

Conclusion: The raw data obtained in this study demonstrate that patients with an osteoarthritic or fused ankle can recover gait speed but that they retain a limp. Total ankle arthroplasty enables a more balanced fluid and symmetrical gait which is much more comfortable for the patient.