A Unique Treatment for Talar Osteonecrosis: Placement of an Internal Bone Stimulator: A Case Report

Electrical stimulation in bone tissue engineering treatments

Electrical stimulation (EStim) has been shown to promote bone healing and regeneration both in animal experiments and clinical treatments. Therefore, incorporating EStim into promising new bone tissue engineering (BTE) therapies is a logical next step. The goal of current BTE research is to develop combinations of cells, scaffolds, and chemical and physical stimuli that optimize treatment outcomes. Recent studies demonstrating EStim's positive osteogenic effects at the cellular and molecular level provide intriguing clues to the underlying mechanisms by which it promotes bone healing. In this review, we discuss results of recent in vitro and in vivo research focused on using EStim to promote bone healing and regeneration and consider possible strategies for its application to improve outcomes in BTE treatments. Technical aspects of exposing cells and tissues to EStim in in vitro and in vivo model systems are also discussed.

Vascularized Pedicle Graft for Talar Osteonecrosis

Vascularized bone grafting for talar avascular osteonecrosis is indicated for patients with modified Ficat and Arlet stage I to III disease with minimal subchondral collapse. Outcomes may be more durable than core decompression alone, especially in patients with more advanced disease. Our preferred method, described in this article, involves core decompression followed by use of a vascularized cuboid pedicle graft placed in the defect. Outcomes reported in a small case series have been encouraging, with more than 80% of patients requiring no further surgery.

Treatment of Osteonecrosis of the Talus

More than 60% of the talar surface area consists of articular cartilage, thereby limiting the possible locations for vascular infiltration and leaving the talus vulnerable to osteonecrosis. Treatment strategies for talar osteonecrosis can be grouped into four categories: nonsurgical, surgical-joint sparing, surgical-salvage, and joint-sacrificing treatments. Nonoperative and joint-sparing treatments include restricted weight-bearing, patellar tendon-bearing braces, bone-grafting, extracorporeal shock wave therapy, internal implantation of a bone stimulator, core decompression, and vascularized or non-vascularized autograft, whereas joint-sacrificing or salvage procedures include talar replacement (partial or total) and arthrodesis. In patients with a Ficat and Arlet grade-I through III osteonecrosis, evidence in favor of a specific treatment is poor, although tibiotalar or tibiotalocalcaneal arthrodesis may represent a suitable salvage operation.