SLR - September 2015 - David A. Engorn

Long-Term Results of Tibialis Anterior Tendon Transfer for Relapsed Idiopathic Clubfoot Treated with the Ponseti Method: A Follow Up of Thirty-Seven to Fifty-Five Years

Reference: Holt JB, Oji DE, Yack HJ, Morcuende JA. Long-term Results of Tibialis Anterior Tendon Transfer for Relapsed Idiopathic Clubfoot Treated with the Ponseti Method: A Follow up of Thirty-seven to Fifty-five Year. J Bone Joint Surg Am. 2015 Jan 7; 97(1): 47-55.

Scientific Literature Review

Reviewed By: David A. Engorn, DPM
Residency Program: MedStar Washington Hospital Center

Podiatric Relevance: Idiopathic congenital talipes equinovarus (clubfoot) has a reported incidence of one to seven per 1,000 live births making it a somewhat common pathology encountered by foot and ankle surgeons. Management includes early onset Ponseti method with serial manipulations and applications of casts with a specific brace regimen. The Ponseti method has proven effective, however, there is a reported prevalence of 7 percent to 56 percent of dynamic relapse in deformity with this treatment alone. Adjunctive surgical procedures have been incorporated into the deformity correction including the tibialis anterior tendon transfer to potentially prevent relapse. The purpose of this study was to evaluate the long-term outcomes of tibialis anterior tendon transfer on foot function of adult patients treated for relapsed idiopathic clubfoot during childhood.

Methods: This was a Level III retrospective review of prospectively collected data on all patients treated for idiopathic clubfoot with the Ponseti method at the University of Iowa from 1950 to 1967 by Dr. Ignacio Ponseti. Medical records of 126 patients met their inclusion criteria and were evaluated. Thirty-five of these patients, totaling sixty corrected clubfeet, presented to the institution upon request for follow up. Fourteen (40 percent) of the thirty-five patients underwent tibialis anterior tendon transfer for clubfoot relapse and served as the study group. The reference group was the remaining twenty-one patients (60 percent) that did not undergo a tibialis anterior tendon transfer. Average duration from time of tibialis anterior tendon transfer to time of final follow-up was forty-three years.

The outcomes measured include three different foot function questionnaires, a physical exam performed by the senior author (JAM) using the Iowa Ankle Range of Motion Device, radiographic evaluation by two independent observers (DEO and JAM), pedobarographic analysis, and surface electromyography. Statistical analysis included a paired t test, Pearson correlation coefficients to determine significant relationships between variables, and categorical data were analyzed with the chi-square test. Pedobarographic results were compared using the nonparametric Wilcoxon signed-rank test.

Results: No patient in the study group had a relapse or required additional treatment for clubfoot at time of final follow-up, however five patients (seven feet) in the reference group had a relapse of deformity and required repeat casting.

There were no significant differences between groups with regards to the American Academy of Orthopaedic Surgeons (AAOS) Foot and Ankle Outcomes Questionnaire, pain, disability, or function scores determined on the Foot Function Index (FFI). The Laaveg-Ponseti functional ratings were similar, however, the percentage of patients reporting to be “very satisfied” with treatment was higher in the tendon transfer study group. With respect to physical examination, passive ankle range of motion and forefoot inversion-eversion did not differ significantly between groups. Motor strength of the tibialis anterior and peroneal muscles were comparable between groups. On radiographic evaluation, the patients who underwent tibialis anterior tendon transfer had significantly smaller (p = 0.048) anteroposterior talocalcaneal angle compared with the reference patients as well as moderate to severe talar flattening. The tendon transfer group also had moderate to severe osteophyte formation at the navicular-cuneiform joint, however, degenerative changes and osteophyte formation were otherwise similar in the remaining foot joints. Pedobarographic analysis showed no significant difference between the groups particularly with lateral and medial pressure readings. On surface electromyography analysis, the mean tibialis anterior and gastrocnemius muscle amplitudes were slightly decreased in the tendon transfer group.

Conclusions: The results of this study prove long-term effectiveness of nearly fifty years of the tibialis anterior tendon transfer for the treatment of clubfoot relapse. Of particular importance, no patient who underwent the procedure required additional casting or operative intervention. Radiographic differences between the two groups were seen between the two groups, although there was no clinical relevance to these changes. The authors have concluded a tibialis anterior tendon transfer to be an effective procedure to prevent future clubfoot relapse without affecting long-term foot function. 

My conclusion after reading this article is that a tibialis anterior tendon transfer is an effective treatment for these deformities in addition to the widely used and well-documented Ponseti method. This information is helpful as I will be able to better prepare my patients and their families for the long term effects of a tendon transfer when used for this pathology. I would be able to provide them with literature that supports the benefits to augmenting manipulation and casting with a tendon transfer.

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