Purpose: To compare gait kinematics and kinetics in five-year old children treated initially with Ponseti casting versus French physical therapy. A third group, consisting of patients initially treated with these non-operative methods and then undergoing surgery consisting of more than a tendoachilles lengthening, was compared to those children treated entirely non-operatively.
Method: Ninety patients (125 clubfeet) were tested at age five years. Thirty-four feet had undergone only Ponseti treatment, 40 the French program, and 51 had initial non-operative treatment with either the Ponseti or French protocols but later had surgery at an average age of 2+3 years. Kinematics and kinetics were compared to age-matched normal subjects.
Results: Average stance-phase dorsiflexion did not differ between groups or from normal. Incidence of equinus: French 5%, Ponseti 0%; Increased stance-phase dorsiflexion: French 3%, Ponseti 24%, Surgical 18% (p <
0.05). A similar number of feet that were not operated upon at age five had in-toeing: 30% French, 32% Ponseti. Decreased ankle power generation at push-off: 53% French; 47% Ponseti; 67% Surgical. Average ankle power generation: 2.21 W/kg French, 2.36 W/kg Ponseti, 1.97 W/kg Surgical (2.83 W/kg in normal 5-year-old children). There was a difference in ankle power generation between normal feet and both the French and surgical groups (p<
0.001). Feet in the non-operative groups that had undergone Achilles tenotomy (n=28) had similar ankle power to those feet (n=42) that did not have tenotomies (p =0.223). Hip power generation was increased 33% in children who had undergone Ponseti treatment (1.38 W/kg), and 41% after French nonoperative treatment (1.47 W/kg), compared to normal (1.04 W/kg). This may be to compensate for poor ankle push-off.
Conclusion: The gait characteristics of those feet that have not had surgery reveal that the majority had normal ankle kinematics, but reduced efficiency is demonstrated by reduced ankle push-off power, regardless of whether or not an Achilles tenotomy was performed. Decreased ankle power and persistant internal rotation are more frequently seen in feet that have undergone surgery despite initial nonoperative treatment, compared to those treated only by either the Ponseti protocol or the French physical therapy program.