Ankle Arthoplasty and Ankle Arthrodesis: Gait Analysis Compared with Normal Controls

SLR- March 2014- Deena Horn

Reference: Singer; S. Klejman; S. Pinsker; E. Houck; J. Daniels; T. Ankle Arthroplasty and Ankle Arthrodesis: Gait Analysis Compared with Normal Controls. JBJS95.24 191-200, 2013.

Scientific Literature Review

Reviewed by:  Deena Horn, DPM
Residency Program: Inova Fairfax Hospital, Falls Church, VA

Podiatric Relevance: Surgical management of patients with end-stage ankle arthritis has traditionally been ankle arthrodesis with long term results demonstrating pain relief and functional improvement. However, long-term follow-up of these patients show gait abnormalities and further arthritis of surrounding joints. The popularity of total ankle arthroplasty has resurged with many foot and ankle surgeons in the last decade. However, research on the functional gait mechanics is limited. This article looks at the effects of TAR and arthodesis on gait parameters with the understanding that gait abnormalities may cause increased pain, arthritis at adjacent joints and further foot and ankle complications. 

Methods: Patients with isolated ankle arthritis underwent either total ankle arthroplasty using STAR or Hintegra implant, or arthrodesis between the years 2000-2010 by one author. Patients were excluded in the study: in the presence of major lower-limb trauma or pathology, bilateral ankle arthritis, subtalar arthritis, major medical comorbidities, inflammatory seropositive arthritis, previous hip or knee arthroplasties, ipsilateral midfootor triple fusions, neurologic disease causing gait abnormalities, posttraumatic arthritis secondary to open fracture and patients over the age of 80. Patients consented to complete gait analysis study one year post-operatively and a pre-operative and post-operative SF-36 ad AOS outcome measures. 

Gait analysis was performed with all patients barefoot while walking a distance of 10m on a walkway. Gait data were collected at 60 Hz using 7-camera Vicon MX motion capturing system; ground reactive forces were recorded on a force plate. 3D kinematics of the foot were obtained and velocity, cadence, stride length, stance phase and heel rise throughout the gait cycle were measured. Further kinetic gait parameters were also measured including dorsiflexion, plantarflexion,ankle ROM and tibial rotation. 

Results: Thirty-four patients were included in the study: 17 total ankle arthroplasty and 17arthrodesis. Nine of the patients in the total ankle group had a STAR prostheses and eight with Hintegra prosthesis. The authors included a control group of ten subjects with comparable age, sex and BMI. 

Gait was evaluated at approximately 1.5 years for patients with arthrodesis and arthroplasty. The control group had the largest mean sagittal plane ROM, the arthroplasty had an intermediate and the arthrodesis had the least amount of motion. The mean dorsiflexion for the arthroplasty group was 11.9 degrees butonly 6.8 for the arthrodesis group. Coronal plane motion was similar in all groups. The mean ankle power, ankle plantarflexion and ankle moment at heel rise was greatest in the control group compared to the two operative groups. 

Post-operative AOS scores were 1.70 and 1.02 for arthrodesis and arthroplasty respectively had no significant difference. There was no significant difference between the SF-36 PCS and MCS scores in both groups. Radiographic evaluation one-year post operatively showed adequate positioning of the implants and unions sites.

Conclusion: The functional outcome comparison with use of gait analysis demonstrated better kinematic gait parameters for the ankle arthroplasty compared with the arthrodesis at one year follow up. Sagittal plane range of motion was significantly better in patients undergoing arthroplasty however temporal and kinetic parameters were similar. Normal plantarflexion was not achieved in either group. This study shows that neither ankle arthroplasty nor arthrodesis replicate normal ankle function and there is no difference in ankle power, moments or temporal gait parameters.