Podiatric physicians routinely use electric drills for the treatment of nail and skin conditions. The grinding process produces human nail and skin dust that is generally vacuumed into bags in the grinding unit. Many of the nails are thought to be mycotic, particularly because they are obtained from patients with symptoms of dermatophyte infections. Currently, there is limited information available on the detection of fungi from nail dust samples. Herein, we attempt to address this situation and outline some of the difficulties that pathology laboratories face in isolating and identifying dermatophytes from nail samples.
Fifty nail dust bags from podiatric medical clinics across all of the states and territories of Australia were collected and analyzed. Samples from the bags were inoculated onto primary isolation media. Fungal colonies that grew were then inoculated onto potato dextrose agar for identification using standard morphological (macroscopic and microscopic) features.
One hundred fifty-one colonies of dermatophytes were identified from 43 of the 50 samples. In addition 471 nondermatophyte molds were isolated, along with some yeasts and bacteria.
The most common dermatophytes isolated were from the Trichophyton mentagrophytes/interdigitale complexes. Trichophyton rubrum, Trichophyton tonsurans, Trichophyton soudanense, and Epidermophyton floccosum were also isolated. An unidentified group of dermatophytes was also present. The three most common genera of nondermatophyte molds were Aspergillus, Penicillium, and Scopulariopsis, all of which have been implicated in onychomycosis and more general disease. The presence of viable fungal pathogens in the dust could potentially pose a health problem to podiatric physicians.
Erythrasma is a superficial skin infection caused by Corynebacterium minutissimum. Interdigital erythrasma is the most common form and is easily confused with tinea pedis. The aim of this study was to determine the prevalence of interdigital erythrasma in patients with clinically suspected tinea pedis.
This study was performed between January 1, 2011, and January 31, 2012. It included 182 patients who presented with concerns about interdigital lesions. All of the patients were examined with a Wood's lamp, and smears were stained with Gram's method. Direct examination with 20% potassium hydroxide was performed.
Of 182 patients with interdigital lesions, 73 (40.1%) were diagnosed as having erythrasma. The mean ± SD age of the patients with erythrasma was 45.52 ± 10.83 years (range, 22–70 years). Most of the patients with erythrasma were women (56.2%). The most often clinical finding was desquamation. Using only Wood's lamp examination or Gram's staining resulted in 31 (42.5%) or 14 (19.2%) positive patients, respectively. Using Wood's lamp examination and Gram's staining concurrently resulted in 28 positive patients (38.4%).
Interdigital erythrasma is a common condition and can be difficult to differentiate from tinea pedis. Simple and rapid diagnosis can be made with Wood's lamp examination, but Gram's staining is also a useful method, especially in patients with negative Wood's lamp examination findings.
Confirmation of Dermatophytes in Nail Specimens Using In-Office Dermatophyte Test Medium Cultures
Insights from a Multispecialty Survey
Using data from a multicenter nationwide multispecialty survey, the authors investigated the efficacy of in-office dermatophyte test medium (DTM) and central laboratory cultures used to confirm onychomycosis across samples collected by podiatric, dermatologic, and primary-care physicians. The samples collected by podiatric physicians were both positive or both negative in 43% and 27% of patients, respectively. Samples harvested by dermatologists were both positive in 37% of patients and both negative in 32%, while the samples collected by primary-care physicians were both positive in 28% of patients and both negative in 38%. The accuracy of DTM and central laboratory tests is dependent on the proper collection of nail samples, and the accuracy of mycologic test results varied significantly across nail specimens harvested by podiatric, dermatologic, and primary-care physicians. DTM culture was found to be an effective and convenient method of confirming dermatophyte infections in patients with signs of onychomycosis. The data presented here indicate that the special expertise of podiatric physicians in treating foot-related illnesses translates into more accurate mycologic testing. (J Am Podiatr Med Assoc 93(3): 195-202, 2003)
Background: We used a model of lower-extremity ulceration to determine the impact of a podiatric lead limb preservation team on identified relationships among risk factors, predictors of ulceration, amputation, and clinical outcomes of lower-extremity disease in patients with diabetes mellitus.
Methods: A total of 485 patients with diabetes mellitus were randomly selected from the diabetic population and included in this retrospective cohort study. Patients were then stratified into two groups: those who received specialty podiatric medical care and those who did not. Data covering a 5-year period were collected using electronic medical records and chart abstraction to capture detailed treatment characteristics, ulcer status, and surgical outcomes.
Results: Overall, the frequencies of inpatient and outpatient encounters and the durations of hospital stays were significantly greater with increasing wound depth and in the presence of infection. In addition, the overall ulcer incidence was greater in patients with callus (34.3% versus 10.3%, P < .0001) with and without neuropathy (20.4% and 4.1%, P < .0001). Among patients treated in a specialty multidiscipline podiatric medical setting, the proportion of all amputations that were “minor” was significantly increased (33.7% versus 67.3%, P = .0006), and survival was significantly improved (19.5% versus 7.7%, P < .0001).
Conclusions: Early identification of individuals at increased risk for lower-extremity ulceration and subsequent referral for advanced multidiscipline podiatric medical specialty care may decrease rates of ulceration and proximal amputation and improve survival in patients with diabetes mellitus who are at high risk for ulceration and limb loss. (J Am Podiatr Med Assoc 100(4): 235–241, 2010)
This study describes the technique for decompression of the intermetatarsal nerve in Morton's neuroma by ultrasound-guided surgical resection of the transverse intermetatarsal ligament. This technique is based on the premise that Morton's neuroma is primarily a nerve entrapment disease. As with other ultrasound-guided procedures, we believe that this technique is less traumatic, allowing earlier return to normal activity, with less patient discomfort than with traditional surgical techniques.
We performed a pilot study on 20 cadavers to ensure that the technique was safe and effective. No neurovascular damage was observed in any of the specimens. In the second phase, ultrasound-guided release of the transverse intermetatarsal ligament was performed on 56 patients through one small (1- to 2-mm) portal using local anesthesia and outpatient surgery.
Of the 56 participants, 54 showed significant improvement and two did not improve, requiring further surgery (neurectomy). The postoperative wound was very small (1–2 mm). There were no cases of anesthesia of the interdigital space, and there were no infections.
The ultrasound-guided decompression of intermetatarsal nerve technique for Morton's neuroma by releasing the transverse intermetatarsal ligament is a safe, simple method with minimal morbidity, rapid recovery, and potential advantages over other surgical techniques. Surgical complications are minimal, but it is essential to establish a good indication because other biomechanical alterations to the foot can influence the functional outcome.
Background: Several absorbable and nonabsorbable antibiotic carrier systems are available in the adjunctive surgical management of osteomyelitis of the foot, ankle, and lower leg. These carrier systems have significant limitations regarding which antibiotics can be successfully incorporated into the carrier vehicle. The calcium sulfate and hydroxyapatite Cerament Bone Void Filler is a biocompatible, absorbable ceramic bone void filler that can successfully deliver multiple heat-stable and heat-unstable antibiotics that have not been generally used before with antibiotic beads in treating musculoskeletal infections.
Methods: Cerament Bone Void Filler discs with the antibiotics rifampin, vancomycin, tobramycin, cefazolin, cefepime hydrochloride, vancomycin-tobramycin, piperacillin-tazobactam, ceftazidime, and ticarcillin-clavulanate were tested in vitro against methicillin-resistant Staphylococcus aureus.
Results: The zones of inhibition for the Cerament Bone Void Filler antibiotic discs plated against Staphylococcus aureus obtained were 33% to 222% greater than the minimum zones of inhibition breakpoints for bacteria susceptibility as defined by the standard set by the Clinical and Laboratory Standards Institute. Cerament Bone Void Filler discs with the antibiotics plated against Pseudomonas aeruginosa produced zones of inhibition of 93% to 200% greater than the minimum zones of inhibition breakpoints for bacteria susceptibility as defined by the standard set by the Clinical and Laboratory Standards Institute.
Conclusions: The calcium sulfate and hydroxyapatite Cerament Bone Void Filler was an excellent carrier vehicle for multiple antibiotics creating in vitro significant zones of inhibition, thus demonstrating susceptibility against Staphylococcus aureus and Pseudomonas aeruginosa, which holds tremendous promise in treating osteomyeilits. (J Am Podiatr Med Assoc 101(2): 146–152, 2011)
The efficacy of concentrated autologous platelet-derived growth factors in the healing and closure of chronic lower-extremity wounds was evaluated in 24 patients with 33 lower-extremity wounds treated previously for at least 6 months using traditional methods. Surgical wound debridement was performed to convert chronic ulcers into acute wounds. Concentrated autologous platelet-derived growth factors and thrombin were applied to the wound bases and protected with a nonadhering compression dressing that remained intact for 7 days. Wounds were evaluated and the concentrate was reapplied every 2 weeks. Wound closure and complete epithelialization was achieved in 20 wounds. Seventy-five percent or greater wound closure was obtained in three wounds, 50% to 74% closure in three wounds, and 25% to 49% closure in two wounds. Five wounds displayed no improvement. Mean time to complete closure was 11.15 weeks. The application of concentrated autologous platelet-derived growth factors and thrombin resulted in substantial wound healing and wound-diameter reduction. This technique constitutes a safe and effective treatment option and avoids lengthy treatment periods that increase the potential for infection. (J Am Podiatr Med Assoc 96(6): 482–488, 2006)
In this study, we aimed to evaluate the potential use of a 3-phase bone scintigraphy method to determine the level of amputation on treatment cost, morbidity and mortality, reamputation rates, and the duration of hospitalization in diabetic foot.
Thirty patients who were admitted to our clinic between September 2008 and July 2009, with diabetic foot were included. All patients were evaluated according to age, gender, diabetes duration, 3-phase bone scintigraphy, Doppler ultrasound, amputation/reamputation levels, and hospitalization periods. Patients underwent 3-phase bone scintigraphy using technetium-99m methylene diphosphonate, and the most distal site of the region displaying perfusion during the perfusion and early blood flow phase was marked as the amputation level. Amputation level was determined by 3-phase bone scintigraphy, Doppler ultrasound, and inspection of the infection-free clear region during surgery.
The amputation levels of the patients were as follows: finger in six (20%), ray amputation in five (16.6%), transmetatarsal in one (3.3%), Lisfranc in two (6.6%), Chopart in seven (23.3%), Syme in one (3.3%), below-the-knee in six (20%), above the knee in one (3.3%), knee disarticulation in one (3.3%), and two patients underwent amputation at other centers. After primary amputation, reamputation was performed on seven patients, and one patient was treated with debridement for wound site problems. No mortality was encountered during study.
We conclude that 3-phase bone scintigraphy prior to surgery could be a useful method to determine the amputation level in a diabetic foot. We conclude that further, comparative, more comprehensive, long-term, and controlled studies are required.
Fasciotomy and Surgical Tenotomy for Chronic Achilles Insertional Tendinopathy
A Retrospective Study Using Ultrasound-Guided Percutaneous Microresection
Achilles insertional tendon pathology is a common condition affecting a broad range of patients. When conservative treatments are unsuccessful, the traditional open resection, debridement, and reattachment of the Achilles tendon is a variably reliable procedure with significant risk of morbidity. Fasciotomy and surgical tenotomy using ultrasound-guided percutaneous microresection is used on various tendons in the body, but the efficacy has not been examined specifically for the Achilles tendon.
A retrospective review evaluated 26 procedures in 25 patients who underwent Achilles fasciotomy and surgical tenotomy. The Foot Function Index was used to quantify pain, disability, activity limitation, and overall scores.
Mean Foot Function Index scores were as follows: pain, 8.53%; disability, 7.91%; activity limitation, 2.50%; and overall, 6.97%. Twenty index procedures were successful, and two patients repeated the procedure successfully for an overall 84.6% success rate in patients with chronic insertional pathology with mean surveillance of 16 months. There were no infections or systemic complications.
Ultrasound-guided percutaneous microresection is a safe and minimally invasive percutaneous alternative that can be used before proceeding to a more invasive open procedure.
Fungal Diversity and Onychomycosis
An Analysis of 8,816 Toenail Samples Using Quantitative PCR and Next-Generation Sequencing
Onychomycosis is a fungal infection of the nail that is often recalcitrant to treatment and prone to relapse. Traditional potassium hydroxide and culture diagnosis is costly and time-consuming. Therefore, molecular methods were investigated to demonstrate effectiveness in diagnosis and to quantify the microbial flora present that may be contributing to disease.
A total of 8,816 clinically suspicious toenail samples were collected by podiatric physicians across the United States from patients aged 0 to 103 years and compared with a control population (N = 20). Next-generation sequencing and quantitative polymerase chain reaction were used to identify and quantify dermatophytes, nondermatophyte molds, and bacteria.
Approximately 50% of suspicious toenails contained both fungi and bacteria, with the dermatophyte Trichophyton rubrum contributing the highest relative abundance and presence in 40% of these samples. Of the remaining 50% of samples, 34% had bacterial species present and 16% had neither. Fungi only were present in less than 1% of samples. Nondermatophyte molds contributed to 11.0% of occurrences in fungus-positive samples. All of the control samples were negative for fungi, with commensal bacterial species composing most of the flora population.
Molecular methods were successful in efficiently quantifying microbial and mycologic presence in the nail. Contributions from dermatophytes were lower than expected, whereas the opposite was true for nondermatophyte molds. The clinical significance of these results is currently unknown.