Plantar Pressures Following Anterior Tibialis Tendon Transfers in Children with Clubfoot

SLR - September 2014 - Brandon Barrett

Reference:  Kelly A. Jeans, MS, Kirsten Tulchin-Francis, PhD, Lindsay Crawford, MD, Lori A. Karol, MD. Plantar Pressures Following Anterior Tibialis Tendon Transfers in Children with Clubfoot. J Pediatr Orthop 2014; 34(5):552-558

Scientific Literature Review

Reviewed By: Brandon Barrett, DPM
Residency Program: Mount Auburn Hospital, Cambridge, MA

Podiatric Relevance: Orthopaedic non-surgical management of pediatric clubfoot has evolved with the development of Ponseti casting and French Physiotherapy methods. However, up to 37 percent of Ponseti casting and 29 percent following the French Physiotherapy methods go on to relapse of the clubfoot deformity and require surgical intervention.The goal of surgical intervention is to more approximate the distributions of gait plantar pressures by bringing the foot out of a dynamic supination and inverted position. The Anterior Tibial Tendon Transfer (ATTT) to the lateral foot is one of the recommended procedures to help correct this deformity. This is a theurapeutic Level II prospective cohort study with the primary outcome determining whether plantar pressures normalize following ATTT for relapsed clubfoot deformity.

Methods: Thirty children (37 clubfeet) with recurrent idiopathic clubfoot undergoing ATTT were included in the study. All had pre-operative (<six months from procedure date) and one and two-year postoperative dynamic gait analyses measured using the EMED ST Platform. The plantar pressures were compared to an age-matched control group. Twenty-one feet underwent isolated ATTT while sixteen had concomitant soft-tissue procedures (TAL, plantar fascia release, posterior release) and these were addressed comparing postoperative outcomes.  Outcome variables included: peak pressure kPa (PP), contact areas reported as a percentage of the total foot (CA%) and contact time reported as a percentage of the stance time (CT%).

Results: There were no significant differences in any of the postoperative variables between isolated ATTT groups and those with concomitant procedures. There was a significant increase in PP, CT% and CA% of the medial column with a significant decrease in PP, CA% in the lateral column between these groups. When compared to age-matched controls those with either isolated or concomitant ATTT still had a significantly increased CA%, CT%, PP in the lateral mid foot and forefoot. There was a significant improvement in global medialization of plantar pressures when compared to the pre-ATTT data in both operative groups.

Conclusions: There is a high probability that some degree of recurrence of deformities in the pediatric clubfoot population will occur and will require surgical correction following conservative treatment. This prospective study shows that whether ATTT is done alone or in combination with other procedures there is still a significant difference in the distribution of foot pressures when compared to an age-matched control group. Though there is a significant improvement when comparing pre- and post-operative dynamic gait pressures, residual deformity continues to globally lateralize. The expectation that even after tendon transfers there will be "normalization" of plantar pressures may be far reaching.  Limitations of the study included a small sample size. Also, a digital overlay had to be used to make adjustments to the automask allocation, which is another limitation as this is subjective but necessary for a foot that doesn’t make full contact with the pedobarograph, as those seen with recurrent clubfoot.