In cases of severe bone loss, severe deformity and advanced arthritis affecting both the ankle and subtalar joints, combined arthrodesis (joint fusion) is still indicated. While there is extensive literature regarding the effect on gait with ankle arthrodesis and ankle arthroplasty (joint replacement) there is very little information regarding the objective functional outcomes measured through gait analysis for patients treated with fusion of both the ankle and subtalar joints otherwise known as tibiotalocalcaneal arthrodesis.
A recent study looked to prospectively analyze twenty-one patients who had underwent a tibiotalocalcaneal fusion utilizing a retrograde, intramedullary nail. All patients were able to walk barefoot without use of assistive device and adhered to a gait analysis protocol. The temporospatial measurements included; cadence, step length, walking velocity and total support time. While the kinematic parameters measured sagittal plane motion and total knee and hip motion and the kinetic parameters were ankle power in the sagittal plane and ankle moment as well as hip power. Symmetry of gait pattern was studied by comparing affected and unaffected limbs. This analysis was completed once prior to surgery, while postoperative analysis was performed at a mean follow time of seventeen +/- six months.
This study demonstrated significant improvement postoperatively in cadence, walking speed, step length (of unaffected limb) and total support time. The authors note that the changes in the affected limb may have been attributed to the decrease in pain which would allow for further use of motion of the joints on the unaffected limb or it may be partially attributed to the mechanical stability provided by the arthrodesis. There was significant increase in hip motion postoperatively, which the authors think may represent compensations for loss through sagittal plane motion in the ankle joint. Ankle moment but not ankle power increased postoperatively in the affected limb. Although definitive conclusions could not be drawn from this data, increased hip power may be related to compensatory mechanism due to stiffness in the ankle restricting the ability to “push off” thus the individual would need to pull the extremity forward to advance the limb. Finally, gait symmetry improved significantly following tibiocalcaneal arthrodesis. This symmetry can be clinically useful in correlation with patient perception of their limping affecting both their self-image and overall postsurgical satisfaction.