INBONE Total Ankle Replacement: Current Status

Authors: James K. DeOrio, MD

Journal:  AAOS OrthoPortal

Abstract:  The INBONE Total Ankle (Wright Medical Technology, Arlington, TN) replacement is a modular ankle replacement system consisting of an intramedullary stem whose pieces are inserted through the ankle and pushed up into the tibia to support the tibial tray of the device. The original talar component of the INBONE ankle is a saddle-shaped prosthesis that resurfaces only the top of the talus. A new talar design feature of the INBONE II ankle is a sulcus and two anterior prongs. Between the tibial and talar components of the INBONE, each consisting of a cobalt-chrome alloy, lies an ultra-high–molecular-weight polyethylene spacer locked into the tibial baseplate. In the INBONE II ankle, this polyethylene component is V shaped, to fit into the talar component of the prosthesis. This article describes the use of the INBONE ankle in total ankle arthroplasty and provides a detailed review of the surgical technique used for its achievement.

Keywords:  Total ankle arthroplasty, ankle replacement system, INBONE

Rate of nonunion after First Metatarsal-Cuneiform Arthrodesis Using Joint Curettage and Two Crossed Compression Screw Fixation

Authors: Michael P. Donnenwerth, DPM; Sara L Borkosky, DPM; Bradley P. Abicht, DPM; Elizabeth J. Plovanich, DPM; Thomas S. Roukis, DPM, PhD, FACFAS.

Journal:  JFAS

Abstract:  First metatarsal-cuneiform joint arthrodesis is a commonly performed procedure to correct first ray pathology. The most widely accepted approach is curettage and 2 crossed compression screw fixation followed by a period of non–weight-bearing. Despite adequate joint preparation and stable internal fixation, nonunion has been cited as a known complication. This can lead to the need for revision surgery, which is undesirable and drives healthcare costs. To further investigate this topic, we conducted a systematic review to determine the rate of nonunion after the first metatarsal-cuneiform joint arthrodesis using curettage and 2 crossed compression screw fixation. Studies were eligible for inclusion only if they involved the following: arthrodesis of the first metatarsal-cuneiform joint with curettage and 2 crossed compression screw fixation, a minimum of 25 feet, with a mean follow-up of at least 6 months, and a period of postoperative non–weight-bearing. After considering all the potentially eligible references, 1 (1.8%) evidence-based medicine level I and 4 (7.3%) evidence-based medicine level IV studies met our inclusion criteria. A total of 537 patients (599 feet), 54 (10%) males and 483 (90%) females, with a weighted mean age of 49.4 years, were included. For those studies that specified the exact follow-up, the weighted mean was 30.9 months. A total of 30 nonunions (5%) were reported, with 17 (56.7%) symptomatic. The results of our systematic review revealed a relatively high rate of nonunion for first metatarsal-cuneiform joint arthrodesis with curettage and 2 crossed compression screw fixation, even when performed by experienced surgeons. Therefore, given the available data, additional prospective investigations are warranted, especially in the evaluation and comparison of fixation constructs and postoperative management.

Keywords: hallux valgus, Lapidus, metatarsus primus varus, tarsal-metatarsal joint, surgery