SLR - December 2020 - Scott Burstyn
Normalization of Forefoot Supination After Tibialis Anterior Tendon Transfer for Dynamic Clubfoot Recurrence
Reference: Mindler GT, Kranzl A, Radler C. Normalization of Forefoot Supination After Tibialis Anterior Tendon Transfer for Dynamic Clubfoot Recurrence. J Pediatr Orthop. 2020 Sep;40(8):418-424.
Level of Evidence: Level II
Scientific Literature Review
Reviewed By: Scott Burstyn, DPM
Residency Program: Montefiore Medical Center – Bronx, NY
Podiatric Relevance: Idiopathic congenital clubfoot is a challenging musculoskeletal deformity seen in pediatric orthopedics. The Ponseti method is the gold standard of treatment with success rates greater than 90 percent. However, there are high rates of recurrence after successful correction. Dynamic clubfoot recurrence is often caused by muscle imbalance with forefoot supination and heel varus during swing and at initial contact. Tibialis anterior tendon transfer (TATT) is part of the Ponseti method for the treatment of dynamic clubfoot recurrence. This prospective study used gait analysis with a foot marker set (Oxford foot model) to analyze foot motion before TATT in children initially treated with Ponseti method. These results were compared to an age-matched control group of children without musculoskeletal deformity.
Methods: A level II prospective study. Children with unilateral or bilateral idiopathic clubfoot treated with the Ponseti method and full TATT, between 2014 and 2017, were considered for inclusion. Children with associated neurologic diseases, living outside the country, treated initially at different facilities, patients with split transfers or additional joint or bone procedures were excluded. All patients underwent full TATT under the retinaculum to the ossified lateral cuneiform using the 3-incision technique. Patients underwent gait analysis using Vicon motion capture system. Marker placement was a combination of the Cleveland clinical model and the Oxford foot model. Graphing of data and comparisons between groups were performed with custom script in MATLAB. The relationship of the hindfoot to the tibia, the forefoot to the tibia, and the forefoot to the hindfoot in the sagittal, transverse, and frontal panes were evaluated.
Results: In the study period a total of 94 children with clubfoot underwent 143 TATT procedures. Seventeen children, with 25 clubfeet, met the inclusion criteria and agreed to participate in the study. The control group consisted of 18 children with 36 feet that did not have musculoskeletal disabilities. The mean forefoot supination in relation to the tibia during swing reduced from 12.7 to 5.2 degrees after TATT, compared to the control group of 6.0 degrees. The varus position of the heel was decreased during swing after TATT. Mean maximum ankle moment was increased after TATT. The mean foot progression during stance increased from 2.8 to 3.8 degrees of external rotation after TATT.
Conclusions: The authors concluded that TATT can effectively correct the dynamic components of clubfoot recurrence. The Oxford foot model allowed the authors to evaluate the biomechanical alterations after TATT. It is important that rigid deformities such as subtalar de-rotation or static forefoot adduction must be addressed preoperatively with cast application. Limitations that could be addressed to strengthen future studies include the relatively small sample size and the short follow-up time.