Demineralized freeze-dried bone allograft (DFDBA) has been used extensively in periodontal therapy. The rationale for use of DFDBA includes the fact that proteins capable of inducing new bone; i.e., bone morphogenetic proteins, can be isolated from bone grafts. Commercial bone banks have provided DFDBA to the dental practitioner for many years; however, these organizations have not verified the osteoinductive capacity of their DFDBA preparations. The aim of this study was to determine the ability of commercial DFDBA preparations to induce new bone formation. DFDBA with particle sizes ranging from 200 to 500 microns was received from six bone banks using various bone production methods. Different lots of DFDBA from the same tissue bank were sometimes available. A total of 14 lots were examined. The surface area of bone particles in each sample was measured morphometrically and the pH of a solution containing the particles after suspension in distilled water determined. Samples from each DFDBA lot were implanted intramuscularly (10 mg) or subcutaneously (20 mg) into three different animals and tissue biopsies harvested after 4 weeks. One sample from each tissue bank was implanted and harvested after 8 weeks. At harvest, each area where DFDBA had been implanted was excised and examined by light microscopy. The ability of DFDBA to produce new bone was evaluated and the amount of residual bone particles measured. The results show that bone particles from all tissue banks had a variety of shapes and sizes, both before implantation and after 1 or 2 months of implantation. The pH of particle suspensions also varied between batches, as well as between tissue banks. None of the DFDBA induced new bone formation when implanted subcutaneously. Intramuscular implants from three banks induced new bone formation after 1 and 2 months. DFDBA from two banks caused new bone formation only after 2 months. However, DFDBA from one bank did not induce new bone at all. Particle size before implantation correlated with particle size after implantation. However, particle size did not correlate with ability to induce bone. The results show that commercial DFDBA differs in both size and ability to induce new bone formation, but that the two are not related. The study also indicates that wide variation in commercial bone bank preparations of DFDBA exist and that ability to induce new bone formation also varies widely. Furthermore, the results suggest that methods or assays for evaluating the ability of DFDBA to induce new bone should be developed and standardized.

The objective of this study was to evaluate the efficacy of three off-loading techniques to heal diabetic foot wounds: total contact casts (TCCs), healing sandals (HSs) and a removable boot with a shear-reducing foot bed (SRB). This was a 12-week, single-blinded randomised clinical trial with three parallel treatment groups of adults with diabetes and a foot ulcer (n = 73). Ulcer healing was defined as full reepithelialisation with no drainage. Diabetic patients with grade UT1A or UT2A forefoot ulcers on the sole of the foot were enrolled. Patients with malignancy, immune-compromising diseases, severe peripheral vascular disease (ankle-brachial index < 0·60 or transcutaneous oxygen < 25 mm/Hg), alcohol or substance abuse within 6 months, untreated osteomyelitis or Charcot arthropathy with residual deformity that would not fit the HS or boot were excluded. In the intent-to-treat analysis, significantly higher proportion of patients were healed in the TCC group (69·6%) compared to those treated with the SRB (22·2%, P < 0·05). There was no difference in the rate of healed ulcers in the HS (44·5%) and TCC groups. Ulcers in the TCC group healed faster than those in the HS group (5·4 ± 2·9 versus 8·9 ± 3·5 weeks, P < 0·02). However, there was no difference in the time to healing in the TCC and SRB groups (6·7 ± 4·3 weeks, P = 0·28). Patients who used HS were significantly more active (4022 ± 4652 steps per day, P < 0·05) than those treated with TCCs (1447 ± 1310) or SRB (1404 ± 1234). It is concluded that patients treated with TCCs had the highest proportion of healed wounds and fastest healing time. The novel shear-reducing walker had the lowest healing and highest rate of attrition during the study.

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The purpose of this investigation was to evaluate the diversity of bacteria in diabetic foot osteomyelitis using a 16S rRNA sequencing approach and to compare the results with conventional culture techniques. In this prospective observational study, we obtained 34 bone samples from patients admitted to our hospital with a moderate–severe diabetic foot infection. We analysed the distribution of the 16S rRNA gene sequences in the bone samples, using an Illumina MiSeq Personal Sequencer. We compared the genera that were detected with the cultured pathogens in the bone samples with conventional techniques. In the 23 samples that had positive results with both techniques, Staphylococcus, Corynebacterium, Streptococcus and Propionibacterium spp. were detected in 20, 18, 13 and 11 samples, respectively. Significantly more anaerobes were detected with 16S rRNA sequencing compared to conventional techniques (86.9 % vs. 23.1 %, p = 0.001) and more Gram-positive bacilli were present (78.3 % vs. 3.8 %, p < 0.001). Staphylococcus spp. were identified in all of the sequenced bone samples that were negative with conventional techniques. Mixed genera were present in 83.3 % (5 of 6) of the negative samples. Anaerobic and fastidious organisms may play a more significant role in osteomyelitis than previously reported. Further studies with larger populations are needed in order to fully understand the clinical importance of the microbial diversity of diabetic foot osteomyelitis.

Background We provide evidence to revise the Infectious Diseases Society of America (IDSA) diabetic foot infection classification by adding a separate tier for osteomyelitis and evaluating if moderate and severe infection criteria improve the classification’s ability to direct therapy and determine outcomes. Methods We retrospectively evaluated 294 patients with moderate and severe infections. Osteomyelitis was confirmed by bone culture or histopathology. Soft tissue infection (STI) was based on negative bone culture, magnetic resonance imaging, or single-photon emission computed tomography. We stratified STI and osteomyelitis using IDSA criteria for moderate and severe infections and compared outcomes and complications. Results Osteomyelitis patients had greater antibiotic duration (32.5 ± 46.8 vs 63.8 ± 55.1 days; P &lt; .01), surgery frequency (55.5% vs 99.4%; P &lt; .01), number of surgeries (2.1 ± 1.3 vs 3.3 ± 2.3; P &lt; .01), amputations (26.3% vs 83.4%; P &lt; .01), reinfection (38.0% vs 56.7%; P &lt; .01), and length of stay (14.5 ± 14.9 vs 22.6 ± 19.0 days; P &lt; .01). There were no differences in moderate and severe STI outcomes except for infection readmissions (46.2% vs 25.0%; P = .02), and acute kidney injury (31.2% vs 50.0%; P = .03). There were no differences in moderate and severe osteomyelitis except the number of surgeries (2.8 ± 2.1 vs 4.1 ± 2.5; P &lt; .01) and length of stay (18.6 ± 17.5 vs 28.2 ± 17.7; P &lt; .01). Conclusions The IDSA classification better reflects outcomes if risk categories are stratified by STI or osteomyelitis and moderate and severe infections are not categorized separately.