Midfoot charcot arthropathy with improvement of arch after achilles tendon lengthening: a case report

Management of the Charcot Foot and Ankle: Nonreconstructive Surgery

Diabetic neuroarthropathy is a complication of diabetes mellitus that results in instability of the foot, structural deformity, and soft-tissue breakdown. Commonly, midfoot collapse of the medial, lateral, or both longitudinal arches may result in increased plantar pressures and subsequent midfoot ulceration. Many of these wounds can be successfully managed with local wound care and off-loading; however, surgical intervention becomes necessary in cases of osteomyelitis or when the wound fails to heal despite conservative efforts. In cases where surgical reconstruction may not be indicated, nonreconstructive surgical efforts have shown effectiveness in resolving wounds and allowing patients to return to ambulatory lifestyles. This article serves as an update to current treatment recommendations for the nonreconstructive surgical management of Charcot neuroarthropathy.

Simple model of arch support: Relevance to Charcot Neuroarthropathy

BACKGROUND

Charcot neuropathy is a common complication resulting from poorly controlled diabetes and peripheral neuropathy leading to the collapse, and ultimately the breakdown, of the midfoot. Mechanically, it is likely that a compromised arch support in this, or any other patient group that experiences foot flattening, would be associated with slippage at the distal and proximal interface regions of the plantar surface of the foot and the adjacent support surface. This slippage, although difficult to quantify with standard motion capture systems used in a gait laboratory, could potentially be assessed with systems for monitoring interface shear stresses. However, before investing in such systems, a correlation between arch flattening and interface shear stresses needs to be verified.

METHODS

For this purpose, a sagittal plane model of a foot was developed using a multi-body dynamics package (MSC Adams). This model mimicked a subject swaying back and forth, and was constructed to show the dependence of interface stresses on altered arch support.

FINDINGS

The model's predictions matched typical FootSTEPS data: lengthening of the arch of 1-2 mm, sway oscillations of 0.22-0.33 s and frictional force differences (calcaneus relative to forefoot) of 60 N. Of clinical relevance, when the stiffness of the plantar spring (representing aponeurosis and intrinsic muscles) was reduced by 10%, the frictional force difference increased by about 6.5%.

INTERPRETATION

The clinical implications of this study are that, while arch lengthening of less than 2 mm might be difficult to measure reliably in a gait lab, using shear sensors under the forefoot and hindfoot should allow arch support to be assessed in a repeatable manner.

Subtalar Arthroereisis Implantation in Acquired Neuropathic Pes Planus: A Preliminary Report Detailing a Minimally Invasive Approach to Healing Medial Column Ulcerations

Ulcerations under the medial column in patients with acquired neuropathic pes planus may be intractable to conservative techniques such as regular debridement, offloading, bracing, and accommodative shoes. When surgery becomes necessary for these patients, the foot and ankle surgeon has the option of exostectomy, medial column beaming, medial column fusion, and external fixation, among others. In the case of a flexible midfoot collapse, the option of arthroereisis for indirect medial column support may be warranted. In this preliminary report, the authors detail a technique of Achilles tendon lengthening, arthroereisis implantation, and advanced cellular tissue product application in an attempt at wound coverage and prevention of recurrence. Three patients presenting with intractable medial column ulcerations of ∼1 year's duration underwent this procedure, and within 7 weeks (range 5 to 7), all medial column ulcerations healed. These patients remained healed at last follow-up (average 29 months; range 8 to 44). This preliminary report provides evidence for a minimally invasive procedure aimed at offloading, healing, and preventing recurrence of medial column ulcerations in patients with flexible neuropathic pes planus.

Preliminary Results of Primary Gastrocnemius-Soleus Recession for Midfoot Charcot Arthropathy

Background Treatment of Charcot arthopathy of the foot can be challenging. The goal of this investigation was to determine whether primary gastrocnemius-soleus recession could decrease rate of new ulcers, progression of deformity, and amputation in patients with Charcot arthropathy of the midfoot.Methods A retrospective chart review revealed 28 feet in 24 diabetic patients with radiographic evidence of Charcot arthropathy of the midfoot. They were treated with primary gastrocnemius-soleus recession. Eleven feet in 11 patients had concurrent plantar midfoot ulcers. Three feet in 3 patients were lost to follow-up. Twenty-five feet in 21 patients were followed for an average of 37 months postoperatively (range = 18-79).Results A favorable outcome was defined as healing of existing ulcers, no new ulcers, no obvious progression of deformity, and no amputation. Favorable outcomes were obtained in 22 of 25 feet (18 of 21 patients). Only one patient had a persistent ulcer after gastrocnemius-soleus recession. The other 10 patients with preexisting ulcers healed. Deformity of midfoot progressed in one patient, leading ultimately to transtibial amputation. Another patient developed a knee joint infection and had a transfemoral amputation at another institution.Discussion These preliminary data suggest that primary gastrocnemius-soleus recession is followed by a much lower rate of persistent, recurrent, and new ulceration than previously reported studies. Gastrocnemius-soleus recession seems to aid in the treatment of Charcot arthropathy of the midfoot.

LEVELS OF EVIDENCE

Level IV.