Rapid decrease of cast-induced forces during the treatment of clubfoot using the Ponseti method

Abstract

AimsThe Ponseti method is an effective evidence-based treatment for clubfoot. It uses gentle manipulation to adjust the position of the foot in serial treatments towards a more physiological position. Casting is used to hold the newly achieved position. At first, the foot resists the new position imposed by the plaster cast, pressing against the cast, but over time the tissues are expected to adapt to the new position and the force decreases. The aim of this study was to test this hypothesis by measuring the forces between a clubfoot and the cast during treatment with the Ponseti method.Patients and MethodsForce measurements were made during the treatment of ten idiopathic clubfeet. The mean age of the patients was seven days (2 to 30); there were nine boys and one girl. Force data were collected for several weeks at the location of the first metatarsal and the talar neck to determine the adaptation rate of the clubfoot.ResultsIn all measurements, the force decreased over time. The median (interquartile range) half-life time was determined to be at 26 minutes (20 to 53) for the first metatarsal and 22 minutes (9 to 56) for the talar neck, suggesting that the tissues of the clubfoot adapt to the new position within several hours.ConclusionThis is the first study to provide objective force data that support the hypothesis of adaptation of the idiopathic clubfoot to the new position imposed by the cast. We showed that the expected decrease in corrective force over time does indeed exist and adaptation occurs after a relatively short period of time. The rapid reduction in the forces acting on the foot during treatment with the Ponseti method may allow significant reductions in the interval between treatments compared with the generally accepted period of one week.

What is New in Pediatric Orthopaedic Foot and Ankle

“…The NIPS score continued to be significantly lower after casting in the children who received sucrose solution as compared with children who received milk or water 10. Following casting, one can expect that the foot will adapt to the new position within several hours as the force exerted by the cast significantly decreases over time, especially in the first hour after casting 11…”

“…10 Following casting, one can expect that the foot will adapt to the new position within several hours as the force exerted by the cast significantly decreases over time, especially in the first hour after casting. 11 Ponseti manipulation and casting is effective in treating idiopathic as well as all other types of clubfoot including relapsed clubfoot, [12][13][14] complex clubfoot, 15,16 tethered cord, 17 spina bifida/myelomeningocele, 18,19 neglected clubfeet in adolescents, [20][21][22] arthrogryposis, 23,24 and amniotic band syndrome. 25 Orthopaedic surgeons should be aware that ∼9% of patients with presumed idiopathic clubfeet have an underlying diagnosis.…”

Clubfoot: Review on Assessment, Treatment, Challenges, and Engineering Aspects

“…106 Researchers have attempted to quantify the manipulation force in the Ponseti method and found the applied force variability up to 70% among practitioners. 107 Giesberts et al 108 investigated the forces induced by casting on clubfoot using force sensors, and it was found that the forces reach equilibrium within hours. It suggests that the clubfoot tissues adapt and stresses reduce rapidly.…”

Time-dependent extracellular matrix alterations of young tendons in response to stress relaxation: a model for the Ponseti method

“…By contrast to the physiological loading regime (less than 4% strain) [ 5 ], this strain value is located at the beginning of the linear region of the mechanical profile (electronic supplementary material, figure S1). When a tendon is stretched and the strain is fixed to a value, stress relaxation will occur as a result [ 6 ]. At the same time, tissue remodelling could also occur to recover the structural, mechanical and functional properties of the tendon.…”