The future of spinal cord stereotaxy.

The spinal cord is an integral part of central nervous system, therefore it can be expected that spinal cord has the same properties as the brain. Movement activity is realized by the activation of individual motoneurons of various spinal cord segments under the influence of analytical function of the spinal cord. When a hypothesis is accepted that the mentioned large volume of spinal cord white matter represents the entire length of neuronal network, an idea can be established that the activated motoneurons project through their reticular processes to this connecting network forming a synthetic picture of this movement and after fluent continuity the entire act of movement. Therefore, neuronal network plays the role of dynamic memory.The perspective of spinal cord stereotaxy in functional neurosurgery hypothetically enables a recognition and understanding of how brain and spinal cord communicate in movement performance (Fig. 2, Ref. 6).

Considerations on physiological mechanisms of spinal cord movement performance according to cerebral stimuli.

The process of communication between brain and spinal cord remains unclear. Therefore an attempt supported by spinal cord stereotaxy was made to disclose the physiological mechanisms underlying the cooperation between the brain and spine as generated by the spinal cord. The initializing stimulus was the discovery of motoneuron location in all spinal cord segments providing an organic substrate for spinal cord stereotaxy. What remains to be clarified are the anatomical structures of spinal cord, participating in the feedback between brain and spinal cord. Therefore two possible hypotheses were proposed by the authors. One of them is closely related to the analytical synthetical mechanism of real objects and thoughts depiction in the memory of the brain and in form of concrete ideas it forms the basis for concrete thinking. In case of spinal cord another more probable mechanism should be considered: the process of analysis and synthesis between the participating spinal motoneurons. The mutual neuronal spinal cord connections are capable of depicting the movement pattern, and the movement is transferred by means of the described spinal cord pathways to the memory of the brain as a concrete movement idea. From here the ideas are transferred according to the individual needs backwards by means of another described spinal cord pathway back to the spinal cord, and the spinal cord is the final effector. The process of thinking is the physiological correlation of technical software, but in form of abstract thinking it is transferred to the form of abstract thinking. (Fig. 3, Ref 7). Full Text (Free, PDF) www.bmj.sk.

[Reflection on the physiological mechanisms of movements controlled by the spinal cord-brain interaction]. / Uvaha o fyziologickém mechanizmu pohybové reakce uskutecnované míchou na podnety z mozku.

The process of communication between brain and spinal cord remains unclear. Therefore an attempt supported by spinal cord stereotaxy was made to disclose the physiological mechanism underlying the cooperation between brain and spine as generated by the spinal cord. The initializing stimulus was the discovery of motoneuron location in all spinal cord segments providing the organic substrate for spinal cord stereotaxy. What remained to be clarified were the anatomical structures of spinal cord, participating in the feedback between brain and spinal cord. Therefore two possible hypotheses were proposed by the authors. One is closely related to the analytic-synthetic mechanism of real object and thoughts depiction in the memory of the brain and in the form of concrete ideas forming the basis for concrete thinking. In the case of spinal cord, another more probable mechanism should be considered: The process of analysis and synthesis between the participating spinal motoneurons. The mutual neuronal connections in the spinal cord are capable of depicting the movement pattern and the movement is transferred by means of the described spinal cord pathways to the memory of the brain as a concrete movement idea. From here the ideas are transferred according to the individual needs backwards by means of another described spinal cord pathways back to the spinal cord and the spinal cord is the final effector. The process of thinking is the physiological correlate of technical software, but in the form of abstract thinking it is transferred to the form of abstract thinking.

Interventional and multimodal pain rehabilitation in a child with meralgia paresthetica.

Meralgia paresthetica is a chronic pain syndrome that is extremely rare in the pediatric population. It is manifested by hypesthesia or pain in the distribution of the lateral femoral cutaneous nerve (LFCN) and is typically caused by entrapment as the nerve passes deep to the inguinal ligament. This sensory mononeuropathy is rare in children and diagnosis is typically delayed, often leading to prolonged functional impairment and unnecessary medical testing. A 9-year-old girl presented to the pain clinic with a 6-week history of right anterolateral thigh pain first noticed after a nontraumatic cheerleading practice. Comprehensive laboratory and radiographic evaluation by multiple prior specialists revealed no clear nociceptive source of pain. History and examination were consistent with a diagnosis of idiopathic, compressive meralgia paresthetica. Conservative management including physical therapy was followed for 2 weeks with only mild improvement noted. To facilitate physical therapy, an ultrasound-guided LFCN block was performed which confirmed the diagnosis by providing complete analgesia. The patient reported overall 25% improvement from multimodal therapy at another 2 weeks. A second LFCN block was performed with complete resolution of symptoms and restoration of function. The patient remains pain-free and has returned to walking, running, and competitive sports. The primary goal of pediatric chronic pain management, regardless of pain etiology, is early restoration of function to avoid prolonged absence from school, sports, or other productive activities and limit the psychological burden of chronic disease.

Cefmenoxime therapy in bacterial osteomyelitis.

Cefmenoxime, a new parenteral beta-lactamase-resistant cephalosporin, was evaluated for safety and efficacy in 15 patients (10 male and five female) with acute (1 patient) and chronic (14 patients) osteomyelitis. Diagnosis was made by culture of the surgical biopsy specimen. Osteomyelitis was treated with 8 to 12 g of cefmenoxime per day (mean 9.1 g) for 42 to 66 days (mean 47.3). Staphylococcus aureus was the most frequently isolated organism. Minimum inhibitory concentrations (MICs) of cefmenoxime were determined and all pathogens were inhibited by 12.5 micrograms/ml or less, except for Enterobacter cloacae and Acinetobacter species, both of which had an MIC of 25.0 micrograms/ml. All patients had at least one surgical debridement. Of the 15 patients, 10 (67 percent) had the osteomyelitis "arrested." These patients have been followed up five to 14 months after completion of cefmenoxime therapy. Toxicity studies indicated mild elevations in serum glutamic oxalacetic transaminase and serum glutamic pyruvic transaminase in two patients. Cefmenoxime appears to be a safe and effective antibiotic in the treatment of osteomyelitis.

Indium-111 chloride imaging in chronic osteomyelitis.

Sixty-eight patients with clinically suspected chronic osteomyelitis were studied with [111In]chloride. Fifty-four images were categorized as true positive; seven were categorized as true negative. There were four false-positive studies, two of which were associated with healing cancellous bone grafts. There were three false-negative studies in patients previously treated with long-term antibiotic therapy. Images in eight noninfected healing fractures 3 to 8 mo old were normal. Three patients with infected total hip prostheses had positive images. Two patients with loose prostheses had negative images. This study shows that [111In]chloride imaging is an accurate way to localize chronic osteomyelitis and may overcome some of the disadvantages of [67Ga]citrate such as localization in noninfected healing fractures and in some loose [67Ga]citrate such as localization in noninfected healing fractures and in some loose prostheses.

Indium-111 chloride imaging in the detection of infected prostheses.

Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with [111In]chloride. A final diagnosis was established by culture in 19. Of these, 12 were categorized as true positives and three as true negatives. There were two false-positive studies, occurring in patients with knee prostheses. In both, the culture was obtained by aspiration. Two false negatives were in patients with hip prostheses, one of whom had been on long-term antibiotic suppressive therapy. The sensitivity was 86%, specificity 60%, and accuracy 79%. Seventeen of the proven cases had bone imaging prior to [111In]chloride imaging. All 17 static images were positive and were not helpful in differentiating loosening from infection. Using increased uptake on the blood-pool image as a criteria for infection, the sensitivity was 89%, but the specificity was 0. Adding flow studies made little difference in interpreting the blood-pool images. This study shows that [111In]chloride accurate in evaluating infection in prosthesis than bone imaging.

Comparative evaluation of the diffusion of tobramycin and cefotaxime out of antibiotic-impregnated polymethylmethacrylate beads.

Both tobramycin and cefotaxime diffuse from antibiotic-impregnated polymethylmethacrylate (PMMA) beads in quantities sufficient to inhibit the growth of bacteria on agar lawns or in broth cultures over a 28-day period. Extraction of antibiotic from tobramycin or cefotaxime-impregnated PMMA beads revealed that substantial amounts of both antibiotics remained within the beads despite 28 days of diffusion. Diffusion of antibiotic from the PMMA beads during the initial 3-5 days is much greater than occurs for the remainder of the 4-week period. The results of the study suggest that perhaps tobramycin of cefotaxime-impregnated PMMA beads would produce local levels of antibiotic high enough to sterilize a given dead space for a period of 28 days.

Evaluation of biodegradable cefazolin sodium microspheres for the prevention of infection in rabbits with experimental open tibial fractures stabilized with internal fixation.

Immediate internal fixation of severe open tibial fractures usually is contraindicated due to the high risk of infection. The objective of this study was to evaluate the efficacy of local antibiotic therapy with biodegradable poly-(DL-lactide-co-glycolide) cefazolin-loaded microspheres for the prevention of infection in experimental open fractures stabilized with internal fixation. Rabbits with experimental tibial fractures that were contaminated with Staphylococcus aureus were treated with local application of cefazolin microspheres, an equivalent local dose of free Ancef powder, or systemic Ancef therapy. The bones then were fixed with a four-hole plate, and the animals were observed for 8 weeks. Clinically, deep infection was present in 86% of control animals that received no antibiotics and in 60% of animals that received a 7 day course of systemic Ancef therapy. In contrast, no infections were noted among any of the surviving rabbits that received local therapy with either cefazolin microspheres or free Ancef powder. Significantly higher levels of serum cefazolin were measured at 1 h for animals treated with free Ancef powder (18.7 +/- 6.1 micrograms/ml) than for those treated with cefazolin microspheres (0.57 +/- 0.27 micrograms/ml). Follow-up studies are in progress to evaluate further the potential clinical benefits of local antibiotic therapy for the management of contaminated open fractures in humans.

Osteogenic protein-1 (bone morphogenetic protein-7) in the treatment of tibial nonunions.

BACKGROUND: The role of bone morphogenetic proteins (BMPs) in osseous repair has been demonstrated in numerous animal models. Recombinant human osteogenic protein-1 (rhOP-1 or BMP-7) has now been produced and was evaluated in a clinical trial conducted under a Food and Drug Administration approved Investigational Device Exemption to establish both the safety and efficacy of this BMP in the treatment of tibial nonunions. The study also compared the clinical and radiographic results with this osteogenic molecule and those achieved with fresh autogenous bone. MATERIALS AND METHODS: One hundred and twenty-two patients (with 124 tibial nonunions) were enrolled in a controlled, prospective, randomized, partially blinded, multi-center clinical trial between February, 1992, and August, 1996, and were followed at frequent intervals over 24 months. Each patient was treated by insertion of an intramedullary rod, accompanied by rhOP-1 in a type I collagen carrier or by fresh bone autograft. Assessment criteria included the severity of pain at the fracture site, the ability to walk with full weight-bearing, the need for surgical re-treatment of the nonunion during the course of this study, plain radiographic evaluation of healing, and physician satisfaction with the clinical course. In addition, adverse events were recorded, and sera were screened for antibodies to OP-1 and type-I collagen at each outpatient visit. RESULTS: At 9 months following the operative procedures (the primary end-point of this study), 81% of the OP-1-treated nonunions (n = 63) and 85% of those receiving autogenous bone (n = 61) were judged by clinical criteria to have been treated successfully (p = 0.524). By radiographic criteria, at this same time point, 75% of those in the OP-1-treated group and 84% of the autograft-treated patients had healed fractures (p = 0.218). These clinical results continued at similar levels of success throughout 2 years of observation, and there was no statistically significant difference in outcome between the two groups of patients at this point (p = 0.939). All patients experienced adverse events. Forty-four percent of patients in each treatment group had serious events, none of which were related to their bone grafts. More than 20% of patients treated with autografts had chronic donor site pain following the procedure. CONCLUSIONS: rhOP-1 (BMP-7), implanted with a type I collagen carrier, was a safe and effective treatment for tibial nonunions. This molecule provided clinical and radiographic results comparable with those achieved with bone autograft, without donor site morbidity.

Bony reconstruction in the lower extremity.

The reconstructions of large debridement defects of the tibia are difficult and, at times, discouraging. To maximize the potential for limb salvage, a rigorous patient selection algorithm is essential. Each therapeutic option must consider various host factors, anatomic restraints, physician skills, and institutional resources. In this article, the cost effectiveness and morbidity of two distinct methodologies are compared to bring the guidelines for patient selection to perspective.

Ankle arthrodesis in the presence of ongoing sepsis. Indications, methods, and results.

The prognosis for ankle arthrodeses performed in the presence of chronic joint sepsis is addressed. The described methods afford reliable and highly successful results, even in cases with massive hard- and soft-tissue deficits. An ankle fusion can be reliably accomplished in the presence of wound contamination, inadequate bone stock, and an ischemic soft-tissue envelope. The methods used must be tailored to the anatomic extent of disease, the physiologic condition of the host, and institutional resources.

The management of open tibial fractures with associated soft-tissue loss: external pin fixation with early flap coverage.

Meaningful data on the management of open tibial fractures cannot be obtained unless one categorizes the injury according to fracture type, degree of soft-tissue loss, and the velocity of the injury. Treatment by converting the type III injury to a type II injury with well-vascularized soft tissue is presented. Eighteen patients with 20 type III and type IIIa wounds were treated in a prospective fashion employing a combined orthopedic and plastic surgical scheme based on the tenets of early radical debridement, a "second look" operation, muscle or muscle-skin flap cover within 5 days of injury, external pin fixation, and ambulation within the first 3 weeks of injury. All fractures united in a mean time of 4.0 months. The mean hospitalization was 4.2 weeks. There have been no chronic infection, osteomyelitis, nonunion, shortening, or tissue breakdown.

Chronic osteomyelitis: results of treatment.

As stated previously, approximately 8% of the patients evaluated do not require curative treatment and palliative treatment with suppressive therapy may be successful (Fig 2). For the most part, these are C-hosts for whom the morbidity of treatment is greater than the morbidity of disease or exceeds the expected gain. The overall spectrum of treatment in 411 of my patients (1983-1988) is seen in Table 5. Of the 411 patients, 228 (55%) required a bone graft; of these, 42% were primary grafts. Soft-tissue reconstructions were required in 37% of the entire patient population and in 59% of the type IV lesions. The overall amputation rate was 9%. There were no statistical differences in success rates between stable and unstable lesions, nor when cases were stratified for the type or number of bacteria present. However, compromised patients had a statistically inferior prognosis compared with patients who had normal physiologic profiles (Outline 1).

Indium-111 chloride imaging with ununited fractures.

Twenty patients with ununited fractures and a suspicion of infection had In-111 chloride imaging. Surgically obtained cultures were positive for infection in 12 and negative in eight patients. In-111 chloride images were positive in all 12 patients with infection but also were positive in six of the patients with negative cultures. It is not possible to differentiate infected from noninfected ununited fractures by In-111 chloride imaging.

Adult chronic osteomyelitis.

Distinctions between hematogenous, traumatic, and contiguous forms of chronic osteomyelitis are noted, and treatment discussed on the basis of the literature and of protocols of the adult osteomyelitis service at the University of Texas Medical Branch.

Ankle arthrodesis in the presence of continuous sepsis. Indications, methods, and results.

On 26 patients, 28 ankle fusions were performed and followed 2 or more years. A functional limb salvage was gained in 25 limbs (96%) with an overall arrest rate of 92%. There was one amputation (4%). The major complication rate was 38% for the series and 86% for patients with uncorrected wound-healing deficiencies (B-hosts). All of the first and second treatment failures were associated with a central column deficiency (C-).