SLR- January 2014- Alexander Mount
Reference: Lázaro-Martínez, J.L., Aragón-Sánchez, J., & García-Morales, E. (2013). Antibiotics versus conservative surgery for treating diabetic foot osteomyelitis. A randomized comparative trial. Diabetes Care. 2013 Oct 15.
Scientific Literature Review
Reviewed By: Alexander Mount, DPM
Residency Program: Morristown Memorial Hospital
Methods: Subjects in this study had neuropathic ulcerations with underlying osteomyelitis without any of the following: severe infections according to the IDSA classification, necrotizing soft tissue infection, peripheral arterial disease, Charcot, glycosolated hemoglobin>10, exposed bone within the ulcer, hepatic insufficiency, creatinine values>98 umol/L in women and >106 in men, or an allergy to antibiotics.
Diabetic foot osteomyelitis was diagnosed based on the combination of a positive probe to bone test and the presence of one or more of the following x-ray findings: cortical disruption, periosteal elevation, the presence of a sequestrum or aninvolucrum, and/or gross bone destruction. Neuropathy was diagnosed by the lack of feeling with testing using a Horwell's Biotensiometer or a 10g Semmes-Weinsteinmono filament. After inclusion in the study antibiotics were discontinued in both groups for two weeks. At the two week mark a soft tissue sample from the base of the wound was sent for culture and the patient began his or her randomized treatment protocol.
Patients in the antibiotic group were treated initially with an empiric regime of ciprofloxacin500mg BID, amoxicillin/clavulanic acid 875/125mg TID, ortrimethoprim/sulfamethoxazole 160/800mg BID. The antibiotic treatment was then modified based on the tissue culture results. Antibiotic treatment lasted for a total of 90 days. Antibiotics were discontinued if wound healing occurred before the end of the 90 day treatment period. If healing did not occur, the patient had a positive probe to bone test, and/or progression of bony destruction on x-ray was observed, conservative surgery was performed.Patients in the surgical group received "conservative surgery," which consisted of removal of the infected bone without performing amputation of any part of the foot. Fourteen metatarsal head resections, four bone curettages, two sesamoidectomies, and two arthroplasties were performed. Post-operatively patients received 10 days of empiric antibiotics that were modified based on culture results.
Local treatment of the wound was identical for both treatment groups. All ulcers were treated with Antisorb(R) plus 25 antimicrobial dressing and off loaded with felted padding and a removable cast walker. Wounds were considered healed when there was complete epithelialization of the ulcer or surgical site. Time to healing was defined as the time in weeks from the date of diagnosis of osteomyelitis to the date of healing. All patients were followed for a total of 12 weeks after healing occurred. Reulceration was defined as any ulceration of any depth that developed during the 12-week follow-up period that occurred at the primary site of ulceration, any adjacent site, or the contralateral limb. Recurrence of osteomyelitis was defined as the appearance of bone infection at the initial wound/operative site or an adjacent site that occurred after healing.
Results: The study consisted entirely of forefoot ulcerations. There was no statistical difference in the pre-study size or duration of ulceration between the experimental groups. Primary healing was achieved in 19 (86.3 percent) of subjects who received surgery and 18 (75 percent) of subjects who were treated with antibiotics. There was no statistical significant difference in these results (p=0.33). There was also no statistically significant difference (p=0.72) in the median time to healing between groups (seven weeks for the antibiotic group and six weeks in the surgical group). There was also no statistically significant difference in the amputation rate (p=0.336) or the reulceration rate during the 12-week follow-up (p=0.670). There were no cases of recurrence of osteomyelitis in either group during the study period.
Conclusions: The present study suggests that similar outcomes are achieved when patients are treated with antibiotics versus conservative surgery in osteomyelitis of the forefoot. This study is the first prospective randomized trial comparing these treatment modalities. The authors found that there was no statistically significant difference in the rate of primary healing, median time to healing, reulceration rate, or amputation rate between the treatment groups.
Prior studies have suggested that non-surgical treatment is more cost effective because the potential complications of surgery are avoided. Non-operative treatment is also an attractive option because the biomechanics of the foot are not altered by treatment. Maintenance of biomechanics is often a double edged sword because faulty biomechanics is often the cause of an ulceration in the first place, and obviously would not be addressed by antibiotic therapy alone.The present study has a number of limitations, the sample size was small (46 patients completed the study), all ulcerations were located in forefoot, and there was a relatively short follow-up period (12 weeks). Additionally there was no histopathological confirmation of bone infection in the antibiotic group and the radiographic changes may have been the result of neuroarthropathy rather than bone infection. There was also a statistically significant difference in the age of patients in each group; patients in the antibiotic group were significantly older than the patients in surgical group (ranges of 72-78 and 50-67.2 respectively), which could also be a potentially confounding factor. The location of the ulcerations was also highly variable between groups.
Despite its limitations this study is clinically relevant and should be considered when treating patients with neuropathic ulcerations of the forefoot with underlying osteomyelitis that is not complicated by ischemia, necrosis, or soft tissue infection. While surgery is often considered the "gold standard" in the treatment of osteomyelitis this study lends evidence based support that calls into question this common wisdom as it relates to forefoot ulcerations.