William P. Grant

Electron microscopic investigation of the effects of diabetes mellitus on the Achilles tendon

Fine structural changes in the Achilles tendons of patients with long-term diabetes mellitus were investigated. All patients had clinical and electrophysiological evidence of diabetic neuropathy and had ulceration and/or Charcot neuroarthropathy. Several differences between tendons of diabetic (n = 12) and nondiabetic (n = 5) individuals were observed by electron microscopy. In diabetics, these differences included increased packing density of collagen fibrils, decreases in fibrillar diameter, and abnormal fibril morphology. In one diabetic patient, individual collagen fibrils were tightly apposed so that many areas of tendon appeared as a single mass of closely adhering fibrillae. In addition, foci in which collagen fibrils appeared twisted, curved, overlapping and otherwise highly disorganized were common in specimens from most patients (11 of 12). These morphologic abnormalities in the Achilles tendons of diabetics appear to reflect a poorly known process of structural reorganization that may be the result of nonenzymatic glycation expressed over many years. Such structural changes could contribute to the tightening of the Achilles tendor a phenomenon consistent with clinical observations of extreme shortening of the Achilles tendon-gastrocnemius-soleus complex common in advanced diabetic neuropaths. In patients with diabetic neuropathy, tendon shortening causes severe equinus that may precipitate serious ulceration, stress fractures, and Charcot collapse of the foot. However, in nondiabetics, the fine structure of the Achilles tendon appears normal, consistent with the finding that the ultrastructural changes result from diabetes rather than neuropathy.

A retrospective analysis of 50 consecutive Charcot diabetic salvage reconstructions.

UNLABELLED Between January 2000 and May 2003, 50 consecutive Charcot diabetic salvage procedures were performed on 44 patients (average age 55.1 years). Twenty-four women (26 feet) and 20 men (24 feet) underwent a reconstructive limb salvage procedure for diabetic Charcot neuroarthropathy using a systematic surgical approach involving internal and external fixation. A retrospective analysis of patient satisfaction and clinical outcome was evaluated over a 2- to 5-year postoperative period; 75% of patients completed the SF-36 health survey and a patient satisfaction survey. A reliability analysis found the SF-36 survey to be an adequate health measurement tool in this Charcot neuroarthropathy cohort. Analysis of variance and categorical data analysis showed that the patients improved statistically significantly in response to surgical intervention; however, none of the demographic variables was statistically significantly associated with patient outcomes as measured by the SF-36 and the patient satisfaction survey. LEVEL OF CLINICAL EVIDENCE 2.

The role of gait analysis in planning reconstructive surgery

Reconstructive surgery should restore normal structure and function to the anatomically injured body part. Therefore, it is imperative to familiarize oneself with normal gait and foot function if surgical reconstruction is undertaken. The foot is a quagmire of skin, muscles, tendons, ligaments, bones, nerves, and arteries that act as shock absorbers, load levelers, and propulsive mechanisms. When functioning normally, it can propel the human body when walking to 5 miles per hour, and when running, to 12 miles per hour. It can adapt to the vertical pressures of ballet, the horizontal forces of weightbearing on uneven terrain and even grip the narrow ledges of rock climbing. This resiliency of the foot is attributed to this complex integration of structures functioning sequentially and synchronously thousands of times per day. It truly is an underappreciated organ until pain or deformity render it useless. It has been estimated that a 150-lb person walking 1 mile generates up to 60 tons of force on each foot in normal gait. With the advent of computer-assisted gait evaluations many difficult patterns of gait have been more thoroughly analyzed. This has proved valuable in preoperative evaluation and in postoperative prosthetic and orthotic fabrication. We will attempt to outline the patterns of normal gait, normal functioning musculature, and techniques of gait analysis for the practicing plastic surgeon. Additionally the F-scan (TEKSCAN, INC., South Boston, MA) pressure measuring system will be introduced.

Loss of Receptor for Advanced Glycation End Products (RAGE) Defense A cause of Charcot neuroarthropathy

OBJECTIVE This study investigated the relationship between circulating soluble receptor for advanced glycation end products (sRAGE) and parameters of bone health in patients with Charcot neuroarthropathy (CNA). RESEARCH DESIGN AND METHODS Eighty men (aged 55.3 ± 9.0 years), including 30 healthy control subjects, 30 type 2 diabetic patients without Charcot, and 20 type 2 diabetic patients with stage 2 (nonacute) CNA, underwent evaluations of peripheral and autonomic neuropathy, nerve conduction, markers of bone turnover, bone mineral density, and bone stiffness of the calcaneus. RESULTS CNA patients had worse peripheral and autonomic neuropathy and a lower bone stiffness index than diabetic or control individuals (77.1, 103.3, and 105.1, respectively; P < 0.05), but no difference in bone mineral density (P > 0.05). CNA subjects also had lower sRAGE levels than control (162 vs. 1,140 pg/mL; P < 0.01) and diabetic (162 vs. 522 pg/mL; P < 0.05) subjects, and higher circulating osteocalcin levels. CONCLUSIONS CNA patients had significantly lower circulating sRAGE, with an accompanying increase in serum markers of bone turnover, and reduced bone stiffness in the calcaneus not accompanied by reductions in bone mineral density. These data suggest a failure of RAGE defense mechanisms against oxidative stress in diabetes. Future studies should determine if medications that increase sRAGE activity could be useful in mitigating progression to CNA.

Charcot Collapse: Does Collapse Pattern Dictate Osseous Metabolism?:

Charcot fracture pattern (FP) and Charcot dislocation pattern (DP) are 2 distinct collapse patterns identified in Charcot neuroarthropathy of the foot and ankle. These patterns are believed to demonstrate relative differences in central bone mineral density (BMD), which has been theoretically extrapolated to describe local BMD. To assess variation in local bone composition of FP and DP patients, 10 patients, 5 DP and 5 FP were recruited. The patient’s age, body mass index (BMI), radiographs, central BMD, local BMD, sRANKL (soluble receptor activator nuclear factor kappa-beta ligand), sRAGE (soluble receptors of advanced glycated end-products), and osteocalcin were measured to determined bone metabolic status and density. Central BMD was determined using DEXA (dual-energy X-ray absorptiometry) scans of the hip. peripheral BMD was determined using scans at the level of the ankle mortise and Chopart’s joint, depending on the location of collapse. These scans were then compared with controls. Central and peripheral DEXA scans were significantly reduced in the FP ( P = .002 and P < .0001) when compared with healthy controls. Additionally, FP patients demonstrated statistically significant elevations in sRANKL ( P = .05) and sRAGE ( P = .002) when compared with DP. No significant difference was seen in osteocalcin ( P = 0.22); however, elevated values compared with normal reference ranges suggest increase bone production. These elevations combined with an osteoporotic profile may indicate difficulty of FP patients in repairing micro fracture. Results from this study emphasize the increased risk of nonunion during FP reconstruction, and highlight the variation in bone composition in these 2 Charcot subtypes. Levels of Evidence: Level III

Loss of Receptor for Advanced Glycation End Products (RAGE) Defense

OBJECTIVE This study investigated the relationship between circulating soluble receptor for advanced glycation end products (sRAGE) and parameters of bone health in patients with Charcot neuroarthropathy (CNA). RESEARCH DESIGN AND METHODS Eighty men (aged 55.3 ± 9.0 years), including 30 healthy control subjects, 30 type 2 diabetic patients without Charcot, and 20 type 2 diabetic patients with stage 2 (nonacute) CNA, underwent evaluations of peripheral and autonomic neuropathy, nerve conduction, markers of bone turnover, bone mineral density, and bone stiffness of the calcaneus. RESULTS CNA patients had worse peripheral and autonomic neuropathy and a lower bone stiffness index than diabetic or control individuals (77.1, 103.3, and 105.1, respectively; P < 0.05), but no difference in bone mineral density (P > 0.05). CNA subjects also had lower sRAGE levels than control (162 vs. 1,140 pg/mL; P < 0.01) and diabetic (162 vs. 522 pg/mL; P < 0.05) subjects, and higher circulating osteocalcin levels. CONCLUSIONS CNA patients had significantly lower circulating sRAGE, with an accompanying increase in serum markers of bone turnover, and reduced bone stiffness in the calcaneus not accompanied by reductions in bone mineral density. These data suggest a failure of RAGE defense mechanisms against oxidative stress in diabetes. Future studies should determine if medications that increase sRAGE activity could be useful in mitigating progression to CNA.

Reconstructive surgery of the foot for the plastic surgeon

Plastic surgeons are often called upon to manage ulcerations of the foot in compromised patients. This article serves as an atlas of bone procedures to perform in concert with plastic repair by the plastic surgeon.