"Treatment of Charcot Neuroarthropathy and Osteomyelitis of the Same Foot: A Retrospective Cohort Study."- A Brief Review
Martin Berli*, Lazaros Vlachopoulos, Sabra Leupi, Thomas Boeni, Charlotte Vlachopoulos-Baltin
Department of Orthopedicsn University Hospital Balgrist Zurich, Switzerland
A brief review of the above-mentioned article: forty patients with 43 affected feet and 60 cases of osteomyelitis were included in this study. They were split into two groups, one with osteomyelitis outside and another one with osteomyelitis within the active Charcot region. The results showed that the amputation rate did not differ between the two groups, although in group 1 – osteomyelitis outside the active Charcot region.
amputations were exclusively performed at the forefoot and in group 2 – with osteomyelitis within the active Charcot region – exclusively in the mid- and hindfoot. Amputations in group 2 were, therefore, more high level. The duration of immobilization and antibiotic treatment was significantly longer in group 2. We conclude, that patients treated for osteomyelitis in an active Charcot foot should be considered and treated as separate entities, depending on whether the osteomyelitis is located within or outside the active Charcot region. If osteomyelitis occurs outside the active Charcot region, primary amputation may be preferred to internal resection.
The Charcot – or neuroosteoarthropathic – foot is the final form of a neuropathic foot, which ends in severe deformity and bony destruction1-3. Since the most frequent cause of the neuropathy is long-term diabetes mellitus, it is often also called diabetic neuroosteoarthropathy (DNOAP)4, which is not entirely correct, as several other reasons for neuropathy exist, such as toxins (e.g. alcohol, chemotherapy), deficits of vitamin B12 or folic acid, etc. Neuroarthropathy of the foot was first described by Jean-Martin Charcot (1825-1893) a French neurologist, who worked at the Hôpital de la Pitié-Salpêtriére in Paris5.
The classic symptoms of the disease are redness, warmth and swelling, but – due to the neuropathy – lack of pain. Neuropathy is also the main reason why deformity may develop, as the patient continues to fully weight bear despite an increasing fragility of the bones. Underneath the aforementioned symptoms, the bones become osteopenic and fracture, which may lead to the final shape of the foot, the so-called rocker-bottom deformity. Due to the bony prominences, this shape of the foot is prone to ulcerations and infection. With the ulcerations, there is an increasing risk of infection and – if they are not treated quickly and appropriately – amputation.
Osteomyelitis is one of the main differential diagnoses of the Charcot foot. The central diagnostic tool during treatment of the Charcot foot is magnetic resonance imaging (MRI). It is very difficult to differentiate an active Charcot foot from osteomyelitis. The situation becomes even more difficult if one is dealing with an infected Charcot foot. For this reason, we decided to review our cases of infected Charcot feet, in order to find a pattern and possibly identify treatment recommendations to reduce the number of patients undergoing septicemia or amputation6,7.
Patients who were treated for Charcot foot and osteomyelitis between 2002 and 2012, were selected from our electronic hospital patient data collection. Inclusion criteria were: a diagnosis of Charcot neuroarthropathy (CN) according to the definition and diagnostic criteria of the French neurologist J.M. Charcot, radiographs of the affected foot, and osteomyelitis of the same foot, which was confirmed with radiological findings of osteomyelitis on MRI, positive bone biopsy cultures, and blood tests (i.e., C-reactive protein). Exclusion criteria were: primary treatment at another institution, or a previous fracture due to trauma of the same foot.
Table 1: Factors that potentially influence effects of cognitive stimulation in patients with dementia
|ID||Side||Age||Gender||Sanders||Osteomyelitis||Osteomyelitis Location||Antibiotic Treatment (days)||Initial Surgical Treatment||Immobilizatio n (days)||Treatment Duration (days)||Amputation|
This study included 40 patients with 43 affected feet and a total of 60 cases of osteomyelitis. According to the localization of the osteomyelitis, the cases were divided into two groups: group 1 with osteomyelitis outside the active Charcot region, and group 2 with osteomyelitis within the active Charcot region. Each group consisted of 30 cases: group 1 (osteomyelitis outside the active Charcot region) included 22 patients with 23 affected feet; group 2 (osteomyelitis within the active Charcot region) included 23 patients with 24 affected feet; 5 patients had both, episodes of osteomyelitis outside and within the active Charcot region.
Logistic regression analysis was performed to address clustering of cases within patients, with amputation as the dependent variable and localization of osteomyelitis as the independent variable. Durations of antibiotic therapy and immobilization were calculated in days and analyzed as logarithmic transformed dependent variables in linear regression with robust standard error (i.e., patient identification as a cluster).
We demonstrated that patients in group 2 (osteomyelitis within the active Charcot region) had a longer duration of antibiotic treatment, with a mean of 84.1 ± 51.2 (range 6-236) days8,9. In contrast, group 1 (osteomyelitis outside the active Charcot region) was treated with antibiotics for a mean of 55.7 ± 48.9 (range 9-228) days (Table 1) (p = 0.045).
The duration of immobilization, which was achieved with a total contact cast10 was also extended in group 2 (mean 144 ± 91.8, range 17-389 days) compared to group 1 (mean 83.1 ± 70.5, range 19-304 days; p = 0.01).
The overall amputation rate was statistically similar for both groups (p = 0.09), with 19 amputations (63%) in group 1 (osteomyelitis outside the Charcot region) and 12 amputations (40%) in group 2 (osteomyelitis within the Charcot region). However, patients in group 2 underwent significantly more high level amputations compared to patients in group 1 (p = 0.009). A major amputation (above the ankle) was performed in 6/30 (20%) cases in group 2 and in 3/30 (10%) cases in group 1.
Significant differences in the amputation level (p<0.001), duration of antibiotic treatment (p=0.045), and duration of immobilization (p =0.01) were observed between the groups, which presented with osteomyelitis within the Charcot region versus outside the Charcot region. In the group with osteomyelitis outside the active Charcot region, the elimination of infection amputation could be achieved more quickly, since the affected area could be clearly defined. However, when osteomyelitis is localized within the active Charcot area, it is more difficult to correctly define the borders of the osteomyelitis, due to the bone edema caused by the Charcot disease, which may lead to the risk of too much bone being resected. For this reason, an extended duration of immobilization combined with antibiotic therapy is considered the treatment of choice if the osteomyelitis is located within the active Charcot zone.
The infection was considered to be cleared when inflammatory markers (i.e., C-reactive protein), MRI, and the clinical appearance of the foot, were all within normal parameters again. This was also confirmed with regular follow-up visits, to allow for immediate intervention in case of a reappearance of inflammation or signs of infection.
We concluded that patients treated for osteomyelitis in an active Charcot foot should be considered as separate entities when considering treatment protocols and in future research evaluating outcomes, depending on whether the osteomyelitis is located within or outside the active Charcot region. If osteomyelitis occurs outside the active Charcot region, primary amputation may be preferred to internal resection. Additional research in the form of prospective studies would be beneficial to compare the outcomes of internal resection versus amputation when osteomyelitis occurs outside the active Charcot region.
- Wukich DK, Sung W. Charcot arthropathy of the foot and ankle: modern concepts and management review. J Diabetes Complications. 2009; 23(6): 409-426.
- Rogers LC, Frykberg RG, Armstrong DG, et al. The Charcot foot in diabetes. Diabetes Care. 2011; 34(9): 2123-2129.
- Frykberg RG, Bevilacqua NJ, Habershaw G. Surgical off-loading of the diabetic foot. J Vasc Surg. 2010; 52(3 Suppl): 44S-58S.
- Sanders LJ FR. Diabetic neuropathic osteoarthropathy: the Charcot foot. In The high risk foot in diabetes mellitus. 1991; 325-333.
- Charcot J. Lectures on the diseases of the nervous system delivered at la Salpêtrière. HC Lea. 1879.
- Wukich DK, Hobizal KB, Sambenedetto TL, et al. Outcomes of Osteomyelitis in Patients Hospitalized With Diabetic Foot Infections. Foot Ankle Int. 2016; 37(12): 1285-1291.
- Gazis A, Pound N, Macfarlane R, et al. Mortality in patients with diabetic neuropathic osteoarthropathy (Charcot foot). Diabet Med. 2004; 21(11): 1243-1246.
- Zeun P, Gooday C, Nunney I, et al. Predictors of Outcomes in Diabetic Foot Osteomyelitis Treated Initially With Conservative (Nonsurgical) Medical Management A Retrospective Study. Int J Low Extrem Wounds. 2016; 15(1): 19-25.
- Lesens O, Desbiez F, Theis C, et al. Working Group on Diabetic O: Staphylococcus aureus-Related Diabetic Osteomyelitis: Medical or Surgical Management A French and Spanish Retrospective Cohort. Int J Low Extrem Wounds. 2015; 14(3): 284-290.
- Armstrong DG, Lavery LA, Wu S, et al. Evaluation of removable and irremovable cast walkers in the healing of diabetic foot wounds: a randomized controlled trial. Diabetes Care. 2005; 28(3): 551-554.