Background:
In vitro biomechanical testing of the human foot often involves the use of fresh frozen cadaveric specimens to investigate interventions that would be detrimental to human subjects. The Thiel method is an alternative embalming technique that maintains soft-tissue consistency similar to that of living tissue. However, its suitability for biomechanical testing is unknown. Thus, the aim of this study was to determine whether Thiel-embalmed foot specimens exhibit kinematic and kinetic biomechanical properties similar to those of fresh frozen specimens.
Methods:
An observational study design was conducted at a university biomechanics laboratory. Three cadavers had both limbs amputated, with one being fresh frozen and the other preserved by Thiel's embalming. Each foot was tested while undergoing plantarflexion and dorsiflexion in three states: unloaded and under loads of 10 and 20 kg. Their segment kinematics and foot pressure mapping were assessed simultaneously.
Results:
No statistically significant differences were detected between fresh frozen and Thiel-embalmed sample pairs regarding kinematics and kinetics.
Conclusions:
These findings highlight similar kinematic and kinetic properties between fresh frozen and Thiel-embalmed foot specimens, thus possibly enabling these specimens to be interchanged due to the latter specimens' advantage of delayed decomposition. This can open innovative opportunities for the use of these specimens in applications related to the investigation of dynamic foot function in research and education.
Background:
Below-the-knee amputation (BKA) can be a detrimental outcome of diabetic foot osteomyelitis (DFO). Ideal treatment of DFO is controversial, but studies suggest minor amputation reduces the risk of BKA. We evaluated risk factors for BKA after minor amputation for DFO.
Methods:
This is a retrospective cohort of patients discharged from Denver Health Medical Center from February 1, 2012, through December 31, 2014. Patients who underwent minor amputation for diagnosis of DFO were eligible for inclusion. The outcome evaluated was BKA in the 6 months after minor amputation.
Results:
Of 153 episodes with DFO that met the study criteria, 11 (7%) had BKA. Failure to heal surgical incision at 3 months (P < .001) and transmetatarsal amputation (P = .009) were associated with BKA in the 6 months after minor amputation. Peripheral vascular disease was associated with failure to heal but not with BKA (P = .009). Severe infection, bacteremia, hemoglobin A1c, and positive histopathologic margins of bone and soft tissue were not associated with BKA. The median antibiotic duration was 42 days for positive histopathologic bone resection margin (interquartile range, 32–47 days) and 16 days for negative margin (interquartile range, 8–29 days). Longer duration of antibiotics was not associated with lower risk of BKA.
Conclusions:
Patients who fail to heal amputation sites in 3 months or who have transmetatarsal amputation are at increased risk for BKA. Future studies should evaluate the impact of aggressive wound care or whether failure to heal is a marker of another variable.
Background:
Partial foot amputations (PFAs) are often indicated for the treatment of severe infection, osteomyelitis, and critical limb ischemia, which consequently leads to irreversible necrosis. Many patients who undergo PFAs have concomitant comorbidities and generally present with a severe acute manifestation of the condition, such as gangrenous changes, systemic infection, or debilitating pain, which would then require emergency amputation on an inpatient basis.
Methods:
The purpose of this study was to track the recent prevalence of PFAs and to investigate the current demographic trends of the physicians managing and performing PFAs, specifically regarding medical degree and specialty. Doctors of podiatric medicine are striving to achieve parity with their allopathic and osteopathic surgical counterparts and become a more prominent part of the multidisciplinary approach to limb salvage and emergency surgical treatment. This study evaluated 4 years (2009–2012) of PFA data from the Pennsylvania state inpatient database in the two most populated areas of Pennsylvania: Philadelphia and Allegheny counties. Statistics on medical schools were obtained directly from the accrediting bodies of allopathic, osteopathic, and podiatric medical schools. The goal of this study was to evaluate the general trends of patients undergoing a PFA and to quantify the upswing of podiatric surgeons intervening in the surgical care of these patients.
Results:
The number of partial foot amputations in the United States rose from 2006 to 2012. Podiatric surgeons performed 46% of theses procedures for residents of Philadelphia County from 2009 to 2012. In Allegheny County podiatric physicians performed 42% of these procedures during the same time frame.
Conclusions:
Partial foot amputations are increasing over time. Podiatric Surgeons perform a significant share of these operations. This share is increasing in the most populated areas of Pennsylvania.
Background:
Planovalgus foot prevalence estimates vary widely (0.6%–77.9%). Among the many factors that may influence planovalgus foot development, much attention has been given to body mass index, especially that of children's feet; factors related to psychomotor development have been less studied. We sought to determine the presence of planovalgus foot in children and its association with anthropometric parameters and psychomotor development.
Methods:
A case-control study was conducted in Málaga, Spain, 2012–2013, of 104 schoolchildren (mean ± SD age, 7.55 ± 0.89 years; 45.2% were boys). Age, sex, body mass index, presence of valgus (valgus index, by pedigraphy), and personal history related to psychomotor development of the lower limbs (presence/absence of crawling, age at onset of crawling, age at onset of walking, use of mobility aids) were evaluated.
Results:
Of the children with obesity, 53.7% had valgus deformity in the left hindfoot (odds ratio [OR], 6.94; 95% confidence interval [CI], 2.72–17.70; P < .0001). In the right foot, the corresponding values were 54.5% (OR, 9.08; 95% CI, 3.38–24.36; P < .0001). Multivariate logistic regression showed an increased risk of left planovalgus foot in boys, in children with overweight or obesity, and in those who began walking later. For the right foot, the same risk factors applied except age at onset of walking.
Conclusions:
These results corroborate data from previous studies, which report an association between overweight and obesity and the onset of planovalgus foot in children. In addition, we identify a new risk factor: age at onset of walking.
Background:
We sought to investigate the different configurations of Kirschner wires used in distal femur Salter-Harris (SH) type 2 epiphyseal fracture for stabilization after reduction under axial, rotational, and bending forces and to define the biomechanical effects on the epiphyseal plate and the fracture line and decide which was more advantageous.
Methods:
The SH type 2 fracture was modeled using design software for four different configurations: cross, cross-parallel, parallel medial, and parallel lateral with two Kirschner wires, and computer-aided numerical analyses of the different configurations after reduction were performed using the finite element method. For each configuration, the mesh process, loading condition (axial, bending, and rotational), boundary conditions, and material models were applied in finite element software, and growth cartilage and von Mises stress values occurring around the Kirschner wire groove were calculated.
Results:
In growth cartilage, the stresses were highest in the parallel lateral configuration and lowest in the cross configuration. In Kirschner wires, the stresses were highest in the cross configuration and lowest in the cross-parallel and parallel lateral configurations. In the groove between the growth cartilage and the Kirschner wire interface, the stresses were highest in the parallel lateral configuration and lowest in the cross configuration.
Conclusions:
The results showed that the cross configuration is advantageous in fixation. In addition, in the SH type 2 epiphyseal fracture, we believe that the fixation shape should not be applied in the lateral configuration.
Background:
Despite the importance to patients of driving, no well-established guideline exists to help either the patient or the physician determine when it is safe for the patient to return to driving. Previous studies have recommended 6 weeks postoperatively before patients can return to driving safely. Several scientific studies have found the nationally recommended safe brake time standard to be 1.25 sec (1,250 msec), looking at brake reaction time (BRT) in all types of patients, surgical and nonsurgical.
Methods:
This is a prospective study assessing BRT after individuals are placed in various forms of immobilization (controlled action motion [CAM] boot, surgical shoe). The study also tested whether BRT is different when using the left foot to brake, with immobilization of the right foot.
Results:
All 29 male and 71 female participants in this study (mean age, 35.49 years) were capable of driving and were not currently being treated for any foot or ankle conditions. No differences were found regarding age, sex, and use of assistive devices. The mean BRT while wearing a CAM boot was 713 msec, while using the left foot to brake (CAM boot on the right foot) was 593.86 msec, and while wearing a surgical shoe was 626.32 msec.
Conclusions:
Although most of the study participants were below the nationally recommended safe brake time standard, it was found that not all of the participants fell within these parameters.
The Dynamic Baropodometric Profile of Children with Idiopathic Toe-Walking
A Cross-Sectional Study
Background:
Idiopathic toe-walking (ITW) gait may present in children older than 3 years and in the absence of a medical condition known to cause or be associated with toe-walking gait. It is unknown how this gait type changes pressure distribution in the growing foot. We sought to determine whether children with ITW gait exhibit different plantar pressures and temporal gait features than typically developing children.
Methods:
Children aged 3 to 6 years were recruited who had either a typical heel-toe gait pattern or a diagnosis of ITW. The ITW diagnosis was reported by the parent/caregiver and confirmed through history and physical examination. Temporal gait measures, peak pressures, and impulse percentages were measured. A minimum of ten unshod footprints were collected. Data were compared with unpaired t tests.
Results:
The study included 40 children with typical gait and 56 with ITW gait. The ITW group displayed lower peak pressures at the hallux, midfoot, and hindfoot (P < .05) and higher and lower pressure impulse percentages at the forefoot (P < .001) and hindfoot (P < .001), respectively. The ITW group spent a higher percentage of contact time at all areas of the forefoot and less at the midfoot and rearfoot (P < .05). There were no significant differences in total step duration and foot progression angle between groups (P > .05).
Conclusions:
There were differences in pressure distributions between groups. Understanding these differences may help us better understand the compensations or potential long-term impact that ITW gait may have on a young child's foot. Podiatric physicians may also consider the use of this equipment in the clinical setting to measure outcomes after treatment for ITW.
Fasciotomy and Surgical Tenotomy for Chronic Achilles Insertional Tendinopathy
A Retrospective Study Using Ultrasound-Guided Percutaneous Microresection
Background:
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.
Methods:
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.
Results:
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.
Conclusions:
Ultrasound-guided percutaneous microresection is a safe and minimally invasive percutaneous alternative that can be used before proceeding to a more invasive open procedure.
Foot Kinetic and Kinematic Profile in Type 2 Diabetes Mellitus with Peripheral Neuropathy
A Hospital-Based Study from South India
Background:
A kinetic change in the foot such as altered plantar pressure is the most common etiological risk factor for foot ulcers in people with diabetes mellitus. Kinematic alterations in joint angle and spatiotemporal parameters of gait have also been frequently observed in participants with diabetic peripheral neuropathy (DPN). Diabetic peripheral neuropathy leads to various microvascular and macrovascular complications of the foot in type 2 diabetes mellitus. There is a gap in the literature for biomechanical evaluation and assessment of type 2 diabetes mellitus with DPN in the Indian population. We sought to assess and determine the biomechanical changes, including kinetics and kinematics, of the foot in DPN.
Methods:
This cross-sectional study was conducted at a diabetic foot clinic in India. Using the purposive sampling method, 120 participants with type 2 diabetes mellitus and DPN were recruited. Participants with active ulceration or amputation were excluded.
Results:
The mean ± SD age, height, weight, body mass index, and diabetes duration were 57 ± 14 years, 164 ± 11 cm, 61 ± 18 kg, 24 ± 3 kg/m2, and 12 ± 7 years, respectively. There were significant changes in the overall biomechanical profile and clinical manifestations of DPN. The regression analysis showed statistical significance for dynamic maximum plantar pressure at the forefoot with age, weight, height, diabetes duration, body mass index, knee and ankle joint angle at toe-off, pinprick sensation, and ankle reflex (R = 0.71, R2 = 0.55, F 12,108 = 521.9 kPa; P = .002).
Conclusions:
People with type 2 diabetes mellitus and DPN have significant changes in their foot kinetic and kinematic parameters. Therefore, they could be at higher risk for foot ulceration, with underlying neuropathy and biomechanically associated problems.
Fungal Diversity and Onychomycosis
An Analysis of 8,816 Toenail Samples Using Quantitative PCR and Next-Generation Sequencing
Background:
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.
Methods:
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.
Results:
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.
Conclusions:
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.
