Biomedical subjects
S F Conti
Publications and source records attributed to S F Conti.
Surgical treatment of neuroarthropathic foot deformity.
Twenty-seven feet with neuroarthropathic fracture resulting in significant deformity were treated with surgical reconstruction. The average age of the patients was 57 years with 21 patients having diabetes mellitus an average of 24 years. Five patterns of midfoot collapse were identified. The most common patterns involved abduction and dorsal displacement of the forefoot with equinus of the hindfoot. Preoperative evaluation included a medical assessment, adequate control of blood sugar, and a comprehensive vascular evaluation. Five patients presented for surgical consultation with open plantar ulcers. Four were healed with total contact casting alone whereas one patient required an exostectomy to heal the ulcer before surgery. After reconstruction, all feet had improvement in their weightbearing posture. For feet with midfoot involvement, the average anteroposterior talo-first metatarsal angle increased 5 degrees, and the average lateral talo-first metatarsal angle decreased 6.5 degrees. There was no significant loss of correction at long term follow-up. The average time in a cast postoperatively was 5.7 months, and the time to unrestricted weightbearing was 7 months. All patients were able to wear over-the-counter footwear postoperatively. Significant complications included six nonunions and two feet with extension of the neuroarthropathic process. One nonunion required revision surgery, and the feet with extension of their neuroarthropathic fractures required conversion of a triple arthrodesis to a pantalar fusion and the addition of a triple arthrodesis after a successful midfoot fusion. No infections or amputations occurred as a result of the surgery. Function increased and pain decreased as a result of successful arthrodesis. Surgical reconstruction of midfoot, hindfoot, and ankle neuroarthropathic deformity is a viable alternative to amputation for patients who fail nonoperative care. Proper preoperative evaluation and assessment will result in a rate of complications comparable to foot surgery in nondiabetic patients.
Arthroscopy of the foot and ankle: current concepts review.
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Clinical outcome after subtalar arthroscopy.
We investigated the clinical outcomes of patients with specific symptoms and physical findings of subtalar pathology with nonspecific radiographic findings after subtalar arthroscopy. Preoperative workup included plain radiographs in all of the patients, magnetic resonance imaging in seven patients, and bone scan in six patients. Based on these studies, no patient had significant subtalar arthrosis. Twelve patients underwent subtalar arthroscopy. Clinical outcome was rated with the American Orthopaedic Foot and Ankle Society Hindfoot Score. Preoperatively, the score ranged from 54 to 75, with a mean of 60. Postoperative scores ranged from 53 to 85, with a mean of 71. The follow-up averaged 17.5 months. Preoperative magnetic resonance imaging and bone scan uniformly underestimated the degree of articular damage. There were no operative complications. Three patients improved their scores by 10 points or greater. Two of these patients had debridement of a cartilage flap to a stable base performed. The third patient had an arthroscopically assisted removal of a loose body. Three of the four patients whose scores decreased have progressed to subtalar arthrodesis. We conclude from this small series of patients that arthroscopy is the most accurate method of diagnosing subtalar articular cartilage damage, but that it has limited therapeutic benefit in the treatment of early degenerative joint disease.
Outcome study of subjects with insertional plantar fasciitis.
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Wound-healing risk factors after open reduction and internal fixation of calcaneal fractures.
This retrospective study investigated outcomes of wound healing in a series of 63 consecutive patients with 64 fractures of the calcaneus who underwent open reduction and internal fixation done by two surgeons experienced in this fracture during a 3-year period. Thirty-nine patients were managed preoperatively as outpatient referrals before surgery. Twenty-four patients were admitted directly to the trauma service and were managed as inpatients preoperatively. Minimum patient follow-up was 6 months, with an average follow-up of 18 months. A trend correlating the time between injury and operative intervention with the incidence of complications in wounds was noted; the incidence rose in patients who underwent surgery >5 days after their injury. Two-layered closures had a lower incidence of dehiscence compared to single-layered tension-relieving sutures. Patients with a higher body-mass index (BMI) (kg/ m2) took longer to heal their wounds. Strong trends were noted to link BMI and severity of fractures. In the outpatient group, a history of active smoking preoperatively correlated with increased time to wound healing. In 43 patients, there were no wound-healing complications. In 21 feet, there were varying degrees of wound dehiscence. Average wound healing took 47 days. Risk factors for complications in the wound after calcaneal open reduction and internal fixation include single layered closure, high BMI, extended time between injury and surgery, and smoking. Age, type of immobilization, medical illness (including diabetes), type of bone graft, or use of a Hemovac did not influence wound healing.
Anterolateral soft-tissue impingement in the ankle: diagnosis using MR imaging.
OBJECTIVE: This study was performed to elucidate the MR imaging findings and pitfalls for the diagnosis of anterolateral soft-tissue impingement in the ankle, a cause of chronic ankle pain that can be relieved by arthroscopic resection. MATERIALS AND METHODS: We retrospectively reviewed MR imaging examinations of 18 patients with arthroscopically confirmed anterolateral ankle impingement. The MR images of 18 additional subjects with symptoms that could mimic anterolateral impingement, but who had a surgically confirmed alternate diagnosis (instability, peroneal tendon injury, osteochondral defect, normal arthroscopy) and no evidence of impingement at arthroscopy, served as controls. RESULTS: On the MR imaging studies, nine patients had an ankle effusion, eight of whom showed an abnormal soft-tissue structure in the anterolateral gutter, 2-15 mm in maximal diameter. No soft-tissue mass was seen in the patients without joint fluid. Four control subjects with instability had a similar soft-tissue structure in the anterolateral gutter, but in the control subjects the finding represented a portion of the torn anterior talofibular ligament. CONCLUSION: Anterolateral soft-tissue impingement of the ankle can be suggested by MR imaging when fluid in the lateral gutter outlines an abnormal soft-tissue structure separate from the anterior talofibular ligament.
Results of distal tibial bone grafting in hindfoot arthrodeses.
Distal tibial bone grafting is a safe and effective means of obtaining cancellous bone for hindfoot arthrodesis procedures, providing a sufficient quantity and quality of cancellous bone graft. Fusion rates using this bone graft are no less than those reported in the literature using autologous bone obtained from other sites. The 1% significant complication rate (fracture) of the donor site is low. Relative contraindications to the procedure include concomitant clinically significant peripheral neuropathy and severe osteopenia. Since cortical bone is not available from the distal tibia, procedures requiring corticocancellous strut or block grafts cannot rely solely on distal tibial grafting, although this procedure can be used to supplement iliac crest grafting when necessary.
Plantar pressure measurements during ambulation in weightbearing conventional short leg casts and total contact casts.
Total contact casts have been shown to be effective in healing plantar neuropathic ulcerations. The proposed mechanism of action is reduction of pressure over the ulcer during ambulation. However, there is little information to support this contention. Plantar pressure distribution was studied using standard short leg casts and total contact casts in normal feet. Both types of casts reduced forefoot pressure in study subjects. This occurred because of an increase in plantar surface area exposed to weightbearing forces. While increased force was shifted to the midfoot, there was no increase in pressure due to a corresponding increase in midfoot surface area exposed to this force. No significant difference was noted between standard short leg casts and total contact casts.
Plantar pressure analysis of diabetic rockerbottom deformity in total contact casts.
In a previous study, we examined plantar pressures under normally arched individuals in casts. The investigation described in this article was designed to assess plantar pressure distribution in subjects with Charcot midfoot collapse and rockerbottom deformity in standard short leg casts and total contact casts. Our results show that both types of casts significantly reduced midfoot pressures. No significant differences were noted between the two casting groups.
Tarsal tunnel syndrome caused by an anomalous muscle.
We report the cases of six patients (seven feet) who had tarsal tunnel syndrome in association with an anomalous muscle that was located deep to the flexor retinaculum of the ankle. An accessory flexor digitorum longus muscle was present in six of the ankles and a tibiocalcaneus internus muscle, in one. All of the patients had a release of the tarsal tunnel and a neurolysis of the posterior tibial nerve and its branches in addition to a resection of the anomalous muscle. The duration of follow-up averaged forty-one months (range, twenty-eight to eighty-three months). Although the pain was reduced in four of the six patients, only one patient was completely free of symptoms at the time of the most recent follow-up examination. Four of the six patients were satisfied with the result of the operation.
Anomalous tibial nerve. A case report.
A rare anomaly of a nonterminating tibial nerve is reported. It was found to be associated with tarsal tunnel syndrome. The nerve failed to divide in the tarsal tunnel and in the talocalcaneal canal distally to the Knot of Henry. The branches of the medial and lateral plantar nerves as well as the medial calcaneal nerve, the nerve to the abductor digiti quinti, and motor branches to the abductor hallucis and to the joints, vessels, and skin took origin directly from the tibial nerve. The presence of this nerve anomaly and its relevance to surgery in the posterior ankle region is discussed. Surgeons should be aware of this anomaly to avoid the inadvertent cutting of nerve branches they assume to be of a non-critical nature.
Posterior tibial tendon problems in athletes.
Posterior tibial tendon problems are uncommon sources of disability in athletes. Awareness of the condition and early diagnosis are important to prevent disability and prolonged time away from sports. Appropriate imaging studies will aid in diagnosis. Tendon tears in younger patients are different than the typical ruptures seen in middle-aged and older adults. Treatment must be individualized based on the type of tear and degree of deformity present. Other conditions such as dislocation of the posterior tibial tendon, accessory navicular and exertional compartment syndrome can involve the tibialis posterior muscle and present as diagnostic dilemmas.
Proximal Chevron metatarsal osteotomy: single incision technique.
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Acquisition of Escherichia coli outer membrane proteins by Bdellovibrio sp. strain 109D.
The ability of Bdellovibrio sp. to acquire the OmpF major outer membrane protein from its Escherichia coli prey was examined to determine if there were other outer membrane proteins which could or could not be acquired. Growth of bdellovibrios on mutant prey which were defective in the expression of outer membrane proteins revealed that Bdellovibrio sp. could acquire the OmpC protein in the absence of the OmpF protein. However, the OmpA, LamB, and protein 2 proteins could not be found in the Bdellovibrio Triton-insoluble outer membrane. The disappearance of the OmpF and OmpC proteins from the bdelloplast surface was measured, and it was determined that Bdellovibrio sp. exhibited a kinetic and temporal preference for the OmpF protein. Bdellovibrios could be grown on porin-deficient prey, and the progeny bdellovibrios possessed outer membranes with a protein mass deficiency.
Chemotaxis of Bdellovibrio bacteriovorus toward pure compounds.
Positive chemotaxis by Bdellovibrio bacteriovorus strain UKi2 was measured for 139 compounds. Twenty-one compounds were attractants; sensitive attraction was elicited by acetate, propionate, thioacetate, malonate, cis-oxalacetate, D-glucose-6-phosphate, acetyl coenzyme A, ammonium ion, barium ion, manganous ion, and potassium ion. Several of the attractants for B. bacteriovorus strain UKi2 also were attractants to strains 6-5-S and 114; however, strains 109D and 109J were not attracted by the compounds tested. Of 33 compounds tested, 8 were repellents for B. bacteriovorus strain UKi2: n-caproate, alanine, isoleucine, leucine, phenylalanine, tyrosine, cobaltous chloride, and hydronium ion. None of the organic repellents for strain UKi2 elicited repulson from strains 114 or 109D. However, all three strains of Bdellovibrio show aerotaxis. Several compounds were tested for their effects on viability and predacious growth of B. bacteriovorus strain UKi2. No simple correlation was found between attraction or repulsion and benefit or harm to bdellovibrios. The data are consistent with the view that in nature, the greatest survival value of chemotaxis for bdellovibros may be in aerotaxis, attraction to certain inorganic ions and acetate, and repulsion by hydronium ion.
Characterization of germination and activation of Bdellovibrio bdellocysts.
A simple method of assaying germination of bdellocysts in liquid medium has been devised. Bdellocysts can be induced to germinate by any of eight L-amino acids or the monovalent cations K+ and NH4+. L-Glutamine was the best individual inducer of germination, although the resulting rate of germination was much slower than in a complex medium. The use of a defined germination medium containing L-glutamine, KCl, and NH4Cl produced a faster rate of germination than did complex media. Bdellocysts germinated most rapidly at pH 8.0 and at 35 degrees C and required aerobic conditions. Respiration of bdellocysts began to increase at 3 min after the addition of germinants. Germination was inhibited by respiratory-chain inhibitors and by inhibitors of macromolecular synthesis. When bdellocysts were heat shocked at sublethal temperatures for short periods, there was no effect on the rate of germination in the defined germination medium or in the complex medium. However, heat-shocked bdellocysts germinated at a much faster rate in the presence of single inducers of germination when compared to nonshocked bdellocytes.
Chemotaxis toward amino acids by Bdellovibrio bacteriovorus.
Chemotaxis toward amino acids by Bdellovibrio bacteriovorous strain UKi2 was studied by the capillary technique of Adler (J. Gen. Microbiol. 74:77-91, 1973). Chemotaxis was shown to be optimal when the capillaries were incubated at between 15 and 40 degrees C for 30 min; the optimal pH was between 7.0 and 8.2. The chemotactic response was proportional to the density of the suspension of bdellovibrios up to a density of 10(8) cells/ml. B. bacteriovorus was attracted to L-asparagine, L-cysteine, L-glutamine, glycine, L-histidine, L-lysine, and L-threonine. The possible roles of chemotaxis in the life of B. bacteriovorus are discussed.