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Chronic nonhealing heel ulcerations have been established as an independent risk factor for major amputation, with poor rates of limb salvage success. Partial calcanectomy is a controversial limb salvage procedure reserved for patients with these heel ulcerations. We conducted a retrospective cohort study reviewing 39 limbs that underwent a partial calcanectomy from 2012 to 2018 to evaluate the proportion of patients healed, time to healing, ulcer recurrence, and postoperative functional level compared to the preoperative state. In addition, age, gender, body mass index, smoking status, coronary artery disease, diabetes mellitus, renal insufficiency, dialysis, peripheral arterial disease, method of closure, and percent of calcaneus resected were evaluated. Mean follow-up for our cohort was 2.3 years. We had a 1 year mortality rate of 11%, and a major amputation rate of 18%. Our results demonstrated a 77% healing rate with a median time to healing of 162 days. We found that patients who were closed primarily had a faster time to healing compared to patients who underwent closure by secondary intention. Our data showed that ulcer recurrence developed in 57% of healed limbs. We found that 76% of our patients were ambulatory postoperatively. These results suggest that partial calcanectomy is a viable limb salvage procedure with a predictable level of ambulation and function in a high-risk patient population.

Desmoplastic fibroblastoma (collagenous fibroma) is a rare benign soft-tissue tumor. Often found in the subcutaneous and muscle tissue, it is slowly enlarging and generally not painful or invasive. The literature often describes the tumor to be found in the upper extremities, neck, and back. Full excision of the tumor is the treatment of choice, and the prognosis is generally favorable; there are no documented cases of recurrence after full excision. We present an atypical case of desmoplastic fibroblastoma found on the dorsum of the foot with a larger tumor present in a substantially younger patient than is typical.

Transmetatarsal amputation (TMA) allows for maintenance of ambulatory function in patients with significant forefoot tissue loss. Effective revascularization is key to optimizing limb salvage in patients with chronic limb threatening ischemia (CLTI). We hypothesize that CLTI patients requiring TMA have better healing and functional outcomes with open bypass (OPEN) compared with endovascular (ENDO) revascularization.Consecutive TMAs performed at three affiliated centers between 2008 and 2020 were retrospectively reviewed. Baseline characteristics including WIfI stage, non-invasive vascular studies, healing, and ambulatory outcomes were collected. Catheter-based angiographic images were evaluated using the GLASS system. Primary outcomes were TMA healing and community ambulation, with secondary outcomes of TMA healed at end of study, any ambulatory function postoperatively, major amputation, and mortality. Descriptive statistics, univariate, multivariable, and Kaplan-Meier analyses were performed.346 TMAs were performed in 318 patients, 209 of whom had peripheral artery disease (PAD). Median follow up was 2. 5 years. Patients with PAD had significantly lower rates of healing compared to those without (64% vs. 77%, p=0.007). Revascularization was performed in 185 limbs with 102 treated ENDO and 83 OPEN. Patients who underwent ENDO were significantly less likely to heal their TMA at any time (55% vs. 76%, p=0.003) and less likely to remain healed at the end of study (49% vs 66%, p=0.02). Patients with GLASS stage 3 anatomy were significantly more likely to heal with OPEN (75% vs 45%, p=0.003). Long term ambulation data was available for 72% of revascularized patients. ENDO was associated with lower likelihood of community ambulation after TMA (34% vs 57%, p=0.002). In multivariable analysis, OPEN was significantly associated with TMA healing (OR 2.8, p=0.007) and ambulation (OR 2.9, p=0.001).In patients with CLTI and significant tissue loss requiring TMA, initial OPEN approach to revascularization was associated with improved healing and higher rates of ambulation than ENDO. The metabolic requirement to heal a TMA in CLTI patients may be better met by open revascularization.

Results of NMR studies of the nuclear spin-spin relaxation times at low temperatures are reported for commensurate monolayers of 3 He physisorbed on hexagonal boron nitride. Temperature independent relaxation rates are observed for 0.11< T 3 He atoms. The relaxation times and the inferred effective exchange rates were observed to change significantly on replacing the 3 He atoms with relatively immobile Ne atoms. This result is understood in terms of a large 3-spin exchange in addition to 2-spin exchange.

Results are reported for high frequency pulsed NMR studies of 3He adsorbed on hexagonal boron nitride. The commensurate coverage, corresponding to a 0.75 fraction of a monolayer was studied. The temperature dependence of the nuclear spin-spin relaxation time was measured in the range of 0.1-2 K. From the relaxation times, the quantum mechanical exchange rates are calculated for a triangular array of 3He atoms.

NMR measurements of the nuclear spin–spin relaxation times are reported for commensurate monolayers of 3 He and 3 He –Ne films on boron nitride for temperatures 0.1 K . The results are analyzed in terms of particle–particle exchange motions of the adsorbed 3 He atoms. The effective exchange rates were observed to change significantly on replacing a fraction of the helium atoms with relatively immobile neon atoms. This is understood if there is a significant 3-particle term in the exchange Hamiltonian that is of opposite sign to that of the 2-spin exchange term. Values of the vacancy formation energy for the monolayer coverage and the atom-vacancy exchange rate are also obtained from the experimental observations.

Measurements of the 3He nuclear spin-spin relaxation time, T2, have been carried out for commensurate layers of 3He-Ne mixtures adsorbed on hexagonal boron nitride for temperatures 0.2< T

For many years, arterial reconstructive procedures designed to treat arterial occlusive disease involving the lower extremities were limited to the femoral and popliteal vessels. Arterial bypass procedures involving anastomoses below the knee were thought to be impossible because of the small size of the vessels involved and the limited runoff. However, as technics of vascular surgery have improved and as surgeons have become more familiar with the handling of smaller vessels, successful treatment of more distal arterial occlusions has been possible. Morris et al [I ] in 1959 described the first anastomosis of arterial grafts to the distal popliteal vessel below the knee. Two years later, McCaughan [2] described the first group of patients who had bypass grafts to vessels below the popliteal trifurcation. It soon became apparent that vessels distal to the popliteal artery would support inserted autogenous saphenous vein grafts [3-101. Thereafter, the frequency of arterial bypass grafting to the anterior tibial, posterior tibial, and peroneal arteries in the calf region increased rapidly. More recently, refinements in surgical technics for suturing vessels 2 mm in diameter have resulted in favorable patency rates for arterial anastomoses at the ankle and below [11-141. This report is an analysis of sixteen patients in whom the dorsalis pedis artery was utilized for the distal anastomosis in bypass grafting for arterial occlusive disease.