The impact of instrumented gait analysis on surgical planning: Treatment of spastic equinovarus deformity of the foot and ankle

Background: Despite the logic behind instrumented gait analysis, its specific contribution to clinical and surgical decision making is not well known. Our purpose in this study was to determine the influence of gait analysis with dynamic electromyography upon surgical planning in patients with upper motor neuron syndrome and gait dysfunction. Methods: Two surgeons prospectively evaluated 36 consecutive adult patients with a spastic equinovarus deformity of the foot and ankle. After an initial history and physical exam, each surgeon independently formulated a surgical plan. Surgical treatment options for each individual muscle/tendon unit crossing the ankle included lengthening, transfer, release or no surgery. After the initial clinical evaluation and surgical planning, all patients then underwent instrumented gait analysis collecting kinetic, kinematic and poly-EMG data using a standard protocol by a single experienced physiatrist. Each surgeon reviewed the gait studies and patients independently and again formulated a surgical plan. The surgical plans were compared for each surgeon before and after gait study. The agreement between the two surgeon's surgical plans was also compared before and after gait study. Each patient was evaluated for the clinical outcome of surgery. Results: Overall a change was made in 64% of the surgical plans after the gait study. The frequency of changing the surgical plan was, not significantly different between the more and less experienced surgeons. The agreement between surgeons increased from 0.34 to 0.76 (p=0.009) after the gait study. The number of surgical procedures planned by each surgeon converged after the gait studies. Correction of the varus deformity was seen in all patients that underwent surgical treatment. Conclusion: Instrumented gait analysis alters surgical planning for patients with equinovarus deformity of the foot and ankle and can produce higher agreement between surgeons in surgical planning. Clinical Relevance: The equinovarus deformity is due to a variety of deforming forces and a single, best operation does not exist to correct all equinovarus deformities. Rather, a muscle specific approach that identifies the deforming forces will produce the best outcomes when treating the spastic equinovarus deformity.