Subtalar Release in Clubfeet: A Retrospective Study of 10-Year Outcomes

SLR - August 2009 - JoAnn M. Zotis

References:
Henn, III, R.F., Crawford, D.C., Eberson, C.P., Ehrlich, M.G. (2008). Subtalar release in clubfeet: Aretrospective study of 10-year outcomes. Foot and Ankle International, 29(4), 390-395.


Scientific Literature Review


Reviewed by: JoAnn M. Zotis, DPM
Residency Program: OCPM-UHHS Richmond Medical Center


Podiatric Relevance:
The purpose of this study was to comprehensively evaluate a series of clubfoot patients who were refractory to non-operative management and underwent the same corrective procedure performed by a single senior surgeon.

Methods:
Twenty-two congenital clubfeet (14 patients) that were operated on by one surgeon were evaluated. The feet were evaluated by dynamic pedobarographic analysis, hindfoot mobility, and weightbearing radiographs. Pedobarographic analysis consisted of quantifying peak plantar pressures and forces using an FSCAN in-shoe device. The mean patient age was 8 months and follow up was 10 years. Forty-four patients underwent clubfoot surgery between May 1989-December 1994 by the senior author. Fifteen of the patients had no previous surgery and had no underlying neuromuscular condition. Follow-up data was not obtained on 14 of the 15 patients; therefore the study consisted of 22 idiopathic clubfeet in 14 patients that underwent surgical correction by the senior author. All of the feet had failed conservative treatment which consisted of 3 months of serial casting. Following casting the included patients continued to have the calcaneus positioned directly under the talus, the foot
inverted with dorsiflexion, and without normal eversion the foot positioned in equinus. Each foot was operated on with the same surgical technique. A posteromedial approach was performed with a z-lengthening of the tendoachilles, flexor digitorum longus tendon, tibialis posterior tendon, and flexor hallucis longus tendon. The spring ligament, talonavicular capsule, and superficial deltoid ligament were then sequentially released. The subtalar joint was opened medially and all interosseous ligaments were released followed by the lateral calcaneal fibular ligaments. Once all ligaments were released the calcaneus was then disengaged easily from the talus. Using Kirschner wires positioned through the T-N and T-C, the calcaneus and talus were placed in anatomical alignment. Intra-operative radiographs were taken to verify placement. All
ligaments were repaired, the wound was closed and the leg was placed in a long leg cast. The cast and pins were then removed after 3 months under anesthesia. The follow up evaluation consisted of patient based outcome assessment, physical exam, standard AP and lateral weightbearing radiographs, and pedobarographic analysis. The results were compared to normal published values and plantar peak pressures in all surgical feet were compared to 24 control feet using FSCAN in-shoe monitoring system.

Results:
The patients’ average age at the time of surgery was 8 months and follow up was 10 years. There were no peri-operative complications and no recurrence of the deformity. Two female patients underwent bilateral procedures and both developed bilateral deformities that needed further correction. One developed bilateral calcaneus requiring correction, and one patient (oldest in the study) developed bilateral planovalgus also requiring surgical correction. Foot function and satisfaction was very high for patients and parents. All but one patient participated in athletics and none required orthotics at the time of follow-up. The outcomes for the pediatric clubfoot patients and the control feet were not significant. Hindfoot range of motion was preserved and all feet could be actively dorsiflexed past neutral. Corrected patients were able to walk on their heels as well as walk on their toes without heel sag. The mean AP and lateral talocalcaneal angles were all in normal range for the age of the patient. The pedobarographic data compared pressure gradients in the control group and corrected feet. The corrected feet showed more pressure gradients in the medial-midfoot area demonstrating flattening of the medial arch.

Conclusions:
This study demonstrates that extensive subtalar joint release with aggressive hindfoot realignment will correct a clubfoot deformity that has failed conservative therapy. However, especially in older patients, care must be taken to prevent overcorrection of the deformity.