Talar-Tarsal Stabilization: Rationale and Preliminary Outcomes

CATEGORY: Ankle; Hindfoot INTRODUCTION/PURPOSE: While surgical stabilization of the subtalar joint (arthroeresis) in children remains controversial in the USA, it is practiced worldwide, with reportedly good outcomes. Our purpose is to present a series of patients who met our criteria for calcaneal lengthening, but who opted instead for the less invasive option of talo-tarsal stabilization (TTS). In particular we wanted to assess the incidence of untoward outcomes that may manifest within the first year postoperatively, namely peroneal spasm or painful loosening of the implant, and discuss the management of these problems. METHODS: With IRB approval, we conducted this retrospective review of 32 patients (60 feet) who underwent talo-tarsal stabilization (TTS) for flexible planovalgus deformity and had a minimum of 1 year follow-up. The etiology was idiopathic for the majority, with a few being neurogenic or syndromic. The age range at insertion was 6-15 years, with the younger patients having neuromuscular etiology or underlying syndromes. Concomitant procedures, included percutaneous Achilles lengthening (33 feet), Kidner (9), supramalleolar rotational osteotomy (1), and guided growth for ankle valgus (2). We assessed hindfoot flexibility and alignment, obvserved the gait pattern and compared weightbearing AP and lateral radiographs taken preoperatively and at least one year postoperatively. RESULTS: At a minimum of 1 year follow-up, 50 implants (85%) were retained and the patients reported satisfactory outcomes. Henceforth, those patients will be monitored on a prn basis. In the early post-immobilization phase, peroneal spasm occurred in 3 patients (5 feet). This resolved with Botox injection in the peroneus brevis in 3 patients and required transfer of the peroneus brevis to the peroneus longus in one. One patient experienced early migration of hte implants, and these were repositioned with a good outcome. Due to lingering discomfort, Implants were removed in five patients (10 feet = 15 %). None of these patients have collapsed and required salvage hindfoot osteotomy or calcaneal lengthening. CONCLUSION: For the child with flat feet and unremitting pain talar-tarsal stabilization, combined with other procedures as indicated, offers advantages over the accepted methods of medial shift osteotomy or calcaneal lengthening. It is less invasive, well tolerated and may prove to be definitive. The outcome at 1 year is a good forecast of whether or not further treatment will be required. Osteotomy may be obviated.