540602
research-article2014
FAIXXX10.1177/1071100714540602Foot & Ankle InternationalPinzur
Letter to the Editor Foot & Ankle International® 2014, Vol. 35(7) 742 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1071100714540602 fai.sagepub.com
Author Response
Dear Editor: This letter brings up some very interesting questions. Several investigations published in the medicine/diabetes literature have clearly demonstrated that long-standing diabetics with peripheral neuropathy are likely to be severely vitamin D deficient and have radiographic evidence of significant osteoporosis. While the idea of using an orthosis following removal of the external fixator is interesting, there is no evidence that this would avoid the complication of late stress fracture. Another compounding factor is the fact that North American patients with Charcot foot are generally morbidly obese (average BMI in our series is 39.6), making the orthosis less likely to be effective. All of the stress fractures in our series occurred at the most proximal fixation point of the tibial mounting block. It is clear that this occurrence is due to normally applied loads to very poor quality bone at a stress concentration point. As the writer stated, this is most likely bony failure of abnormal
bone secondary to normally applied stresses. While the idea of the brace is interesting, we feel that simply using fine wires in the mounting block is a simple solution. It has been well demonstrated that pin tract infections are a common cause of “stress fracture” associated with external fixation. That was not the case with our investigation, as none of the fractures occurred through pin tract infection sites. The fractures observed in our series were clearly due to stress concentration in poor quality bone. The methods of pin care associated with the use of circular fixation is highly user-specific with no evidence to support the various methods. I think that a response to this query would simply be opinion and beyond the scope of this investigation. Michael S. Pinzur, MD Loyola University Health System, Maywood, IL, USA Email: [email protected]
Downloaded from fai.sagepub.com at Univ of Connecticut / Health Center / Library on May 30, 2015
research-article2014
FAIXXX10.1177/1071100714540602Foot & Ankle InternationalPinzur
Letter to the Editor Foot & Ankle International® 2014, Vol. 35(7) 742 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1071100714540602 fai.sagepub.com
Author Response
Dear Editor: This letter brings up some very interesting questions. Several investigations published in the medicine/diabetes literature have clearly demonstrated that long-standing diabetics with peripheral neuropathy are likely to be severely vitamin D deficient and have radiographic evidence of significant osteoporosis. While the idea of using an orthosis following removal of the external fixator is interesting, there is no evidence that this would avoid the complication of late stress fracture. Another compounding factor is the fact that North American patients with Charcot foot are generally morbidly obese (average BMI in our series is 39.6), making the orthosis less likely to be effective. All of the stress fractures in our series occurred at the most proximal fixation point of the tibial mounting block. It is clear that this occurrence is due to normally applied loads to very poor quality bone at a stress concentration point. As the writer stated, this is most likely bony failure of abnormal
bone secondary to normally applied stresses. While the idea of the brace is interesting, we feel that simply using fine wires in the mounting block is a simple solution. It has been well demonstrated that pin tract infections are a common cause of “stress fracture” associated with external fixation. That was not the case with our investigation, as none of the fractures occurred through pin tract infection sites. The fractures observed in our series were clearly due to stress concentration in poor quality bone. The methods of pin care associated with the use of circular fixation is highly user-specific with no evidence to support the various methods. I think that a response to this query would simply be opinion and beyond the scope of this investigation. Michael S. Pinzur, MD Loyola University Health System, Maywood, IL, USA Email: [email protected]
Downloaded from fai.sagepub.com at Univ of Connecticut / Health Center / Library on May 30, 2015
