Preliminary clinical experience with the Bryan Cervical Disc Prosthesis

OBJECTIVE

The concept of accelerated degeneration of adjacent disc levels as a consequence of increased stress caused by interbody fusion of the cervical spine has been widely postulated. Therefore, reconstruction of a failed intervertebral disc with a functional disc prosthesis should offer the same benefits as fusion while simultaneously providing motion and thereby protecting the adjacent level discs from the abnormal stresses associated with fusion. This study was designed to determine whether a new, functional intervertebral cervical disc prosthesis can provide relief from objective neurological symptoms and signs, improve the patient's ability to perform activities of daily living, decrease pain, and provide stability and normal range of motion.

METHODS

We conducted a prospective, concurrently enrolled, multicenter trial of the Bryan Cervical Disc Prosthesis (Spinal Dynamics Corp., Mercer Island, WA) for the treatment of patients with single-level degenerative disc disease of the cervical spine. Patients with symptomatic cervical radiculopathy and/or myelopathy underwent implantation with the Bryan prosthesis after a standard anterior cervical discectomy. At scheduled follow-up periods, the effectiveness of the device was characterized by evaluating each patient's pain, neurological function, and range of motion at the implanted level.

RESULTS

Analysis included data regarding 60 patients at 6 months with 30 of those patients at 1 year. Clinical success at 6 months and 1 year after implantation was 86 and 90%, respectively, exceeding the study's acceptance criteria of 85%. These results compare favorably with the short-term clinical outcomes associated with anterior cervical discectomy and fusion reported in the literature. At 1 year, there was no measurable subsidence of the devices (based on a measurement detection threshold of 2 mm). Evidence of anterior and/or posterior device migration was detected in one patient and suspected in a second patient. There was no evidence of spondylotic bridging at the implanted disc space. The measured range of motion in flexion-extension, as determined by an independent radiologist, ranged from 1 to 21 degrees (mean range of motion, 9 +/- 5 degrees). No devices have been explanted or surgically revised.

CONCLUSION

Discectomy and implantation of the device alleviates neurological symptoms and signs similar to anterior cervical discectomy and fusion. Radiographic evidence supports normal range of motion. The procedure is safe and the patients recover quickly. Restrictive postoperative management is not necessary. However, only after long-term follow-up of at least 5 years will it become clear whether the device remains functional, thus confirming these early favorable results. In addition, the influence on adjacent motion segments can be assessed after at least 5 years of follow-up.

An evaluation of the utility of the CEN categorical structure for nursing diagnoses as a terminology model for integrating nursing diagnosis concepts into SNOMED

We evaluated the utility of the CEN Categorical Structure for Nursing Diagnoses as a terminology model for integrating nursing diagnosis concepts into SNOMED. First, we dissected nursing diagnosis term phrases from two source terminologies (North American Nursing Diagnosis Association (NANDA) Taxonomy 1 and Omaha System) into the semantic categories of the CEN categorical structure. Second, we critically analyzed the similarities between the semantic links in the CEN model and the semantic links used to formally define diagnostic concepts in SNOMED RT and SNOMED CT. Our findings demonstrated that focus, bearer, and judgment were present in 100% of the NANDA and Omaha term phrases. The Omaha term phrases contained no additional descriptors beyond those considered mandatory in the CEN model. In contrast, at least 3% of NANDA diagnoses included a term in each semantic category of the categorical structure. The comparison among the semantic links showed that neither SNOMED RT and SNOMED CT currently contain all the semantic links needed to model the two source terminologies for integration. In conclusion, our findings support the potential utility of the CEN categorical structure as a terminology model for dissecting nursing diagnostic concepts for integration into SNOMED RT and SNOMED CT. However, in order to accomplish this task, appropriate semantic links must be added to SNOMED RT and SNOMED CT.

Hyperactivity and impulsiveness in rats fed diets supplemented with either Aroclor 1248 or PCB-contaminated St. Lawrence river fish

We examined whether exposure to polychlorinated biphenyls (PCBs) around puberty would produce hyperactivity and impulsiveness in adult Sprague-Dawley rats. Randomly assigned groups consumed food containing environmental concentrations of Aroclor 1248, PCB-contaminated St. Lawrence River carp, or corn oil (control). All received operant training to a final multiple (mult) 120-s, fixed interval (FI), 5-min extinction (EXT) schedule. Pressing rates of both exposed groups for drops of water averaged more than 1.5 times that of controls, especially toward the end of the 120-s interval. This overactivity included bursts with short (< or =0.5 s) interresponse times (IRTs), behavior characteristic of hyperactive boys and genetically hyperactive rats. The exposed groups also overreacted to the decreases in reinforcement density associated with transition to the final schedule. The results were interpreted in terms of the possible alterations in the animals' reinforcement mechanisms and the possible neurotoxic effects of PCB exposure.

Perspective Transformation in RN-to-BSN Distance Education

This study examines perspective transformation (or professional resocialization) in RN-to-BSN students obtaining their degree by distance education. A socialization scale was used to compare newly admitted and graduating RN-to-BSN students who had taken their courses onsite, by distance education, or a mixture of the two methods. The scores of entering and graduating RN-to-BSN students also were compared to those of graduates from the generic program to identify if program and experience are factors in scores achieved. Results indicate that all BSN graduates had significantly higher scores than the diploma-prepared nurses entering the RN-to-BSN program. RN-to-BSN graduates who had used distance education had the highest scores, followed by the onsite RN-to-BSN students. Students who had taken a mixture of distance and onsite courses had scores similar to those of generic program graduates. Experience and full-time employment status were significantly associated with higher scores among graduating RN-to-BSN students. Implications for nurse educators working with RN-to-BSN students who use distance education are discussed.

Use of an outcome by gestation table for extremely premature babies: a cross-sectional survey of the views of parents, neonatal nurses and perinatologists

OBJECTIVES

To promote family-centered care and strengthen the process of informed consent it is essential that parents have access to information on the problems their baby may face. We have constructed an Outcome by Gestation Table (OGT) with information on survival, short-term complications plus treatments of the most recent cohort of babies born at different gestations from 23 to 28 weeks. This study documents the views on the table from parents of babies < 29 weeks gestation, neonatal nurses, and doctors.

STUDY DESIGN

A copy of the OGT and a questionnaire seeking views regarding the OGT was sent to the parents' support group (Preemie-List), 71 randomly chosen perinatologists in Australia and to the 35 nurses working in our NICU. Differences between groups were analyzed using chi 2 analysis.

RESULTS

Forty-eight parents participated in the study. Forty-three (60.5%) doctors and 24 (68.5%) neonatal nurses replied. The three groups agreed that the OGT is not misleading. The majority of doctors feel that the table: is easy to understand but has too much information; is useful but they are ambivalent about using it in their practice. The results were highly significant with parents being most positive and accepting of the OGT, next nurses and finally doctors.

CONCLUSION

It is important to seek the views of both consumers and carers on any aid in communication in the NICU.

Standards for nursing terminology

Terminology work in nursing has given rise to an increasing number of nursing terminologies. These generally take the form of controlled vocabularies. Because of the limitations of the controlled vocabulary approach, individual terminologies tend to be tuned to meet the specific needs of their intended users. Differences between terminologies are now a significant barrier to the comparison and interchange of health information. To agree on a single, multipurpose terminology would be problematic. However, several options for resolving unnecessary differences between nursing terminologies are currently being explored by international standards bodies and other groups, such as the U.S. Nursing Vocabulary Summit. One such option is the use of a terminology model to facilitate evolution toward a more coherent range of terminologies. The authors describe the motivation behind the development of a standard for nursing terminologies. They explain how a terminology model might form the basis for such a standard through a description of the approach taken by CEN TC251 (the Health Informatics Technical Committee of the European Committee for Standardization). They also discuss possible limitations of standardization.

Direct anterior screw fixation for recent and remote odontoid fractures

OBJECT

The management of odontoid fractures remains controversial. Only direct anterior screw fixation provides immediate stabilization of the spine and may preserve normal C1-2 motion. To determine the indications, optimum timing, and results for direct anterior screw fixation of odontoid fractures, the authors reviewed the surgery-related outcome of patients who underwent this procedure at two institutions.

METHODS

One hundred forty-seven consecutive patients (98 males and 49 females) who underwent direct anterior screw fixation for recent (< or = 6 months postinjury [129 patients]) or remote (> or = 18 months postinjury [18 patients]) Type II (138 cases) or III (nine cases) odontoid fractures at the University of Utah (94 patients) and National Institute of Traumatology in Budapest, Hungary (53 patients) between 1986 and 1998 are included in this study (mean follow up 18.2 months). Data obtained from clinical examination, review of hospital charts, operative findings, and imaging studies were used to analyze the surgery-related results in these patients. In patients with recent fractures there was an overall bone fusion rate of 88%. The rate of anatomical bone fusion of recent fractures was significantly (p < or = 0.05) higher in fractures oriented in the horizontal and posterior oblique direction (compared with anterior oblique), but this finding was independent (p > or = 0.05) of age, sex, number of screws placed (one or two), and the degree or the direction of odontoid displacement. In patients with remote fractures there was a significantly lower rate of bone fusion (25%). Overall, complications related to hardware failure occurred in 14 patients (10%) and those unrelated to hardware in three patients (2%). There was one death (1%) related to surgery.

CONCLUSIONS

Direct anterior screw fixation is an effective and safe method for treating recent odontoid fractures (<6 months postinjury). It confers immediate stability, preserves C1-2 rotatory motion, and achieves a fusion rate that compares favorably with alternative treatment methods. In contradistinction, in patients with remote fractures (> or = 18 months postinjury) a significantly lower rate of fusion is found when using this technique, and these patients are believed to be poor candidates for this procedure.

Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance?

Fatigue sustained during short-term, high-intensity exercise in humans is associated with the inability of skeletal muscle to maintain a high rate of anaerobic ATP production from phosphocreatine hydrolysis. Ingestion of creatine monohydrate at a rate of 20 g/d for 5-6 d was shown to increase the total creatine concentration of human skeletal muscle by approximately 25 mmol/kg dry mass, some 30% of this in phosphorylated form as phosphocreatine. A positive relation was then shown between muscle creatine uptake and improvements in performance during repeated bouts of maximal exercise. However, there is no evidence that increasing intake > 20-30 g/d for 5-6 d has any potentiating effect on creatine uptake or performance. In individuals in whom the initial total creatine concentration already approached 150 mmol/kg dry mass, neither creatine uptake nor an effect on phosphocreatine resynthesis or performance was found after supplementation. Loss of ATP during heavy anaerobic exercise was found to decline after creatine ingestion, despite an increase in work production. These results suggest that improvements in performance are due to parallel improvements in ATP resynthesis during exercise as a consequence of increased phosphocreatine availability. Creatine uptake is augmented by combining creatine supplementation with exercise and with carbohydrate ingestion.

Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function

BACKGROUND

The use of creatine (Cr) as a nutritional supplement to aid athletic performance has gained widespread popularity among athletes. However, concerns have recently been expressed over potentially harmful effects of short and long term Cr supplementation on health.

METHODS

Forty eight young healthy subjects were randomly allocated to three experimental protocols aimed at elucidating any potential health risks associated with five days (20 g/day) to nine weeks (3 g/day) of Cr supplementation. Venous blood samples were collected before and after periods of Cr supplementation and were analysed for some haematological indices, and for indices of hepatic, muscular, and renal dysfunction.

FINDINGS

All measured indices were well within their respective normal range at all times. Serum creatinine concentration tended to be increased the day after Cr supplementation. However, values had returned to baseline six weeks after the cessation of supplementation. These increases were probably attributable to increased creatinine production rather than renal dysfunction. No indication of impairment to the haematological indices measured, hepatic function, or muscle damage was apparent after Cr supplementation.

INTERPRETATION

These data provide evidence that there are no obvious adverse effects of acute or more chronic Cr supplementation on the haematological indices measured, nor on hepatic, muscle, and renal function. Therefore there is no apparent health risk associated with Cr supplementation to healthy people when it is ingested in quantities that have been scientifically proven to increase muscle Cr stores.

Direct anterior screw fixation for recent and remote odontoid fractures

Object

The management of odontoid fractures remains controversial. Only direct anterior screw fixation provides immediate stabilization of the spine and may preserve normal C1–2 motion. To determine the indications, optimum timing, and results for direct anterior screw fixation of odontoid fractures, the authors reviewed the surgery-related outcome of patients who underwent this procedure at two institutions.

Methods

One hundred forty-seven consecutive patients (98 males and 49 females) who underwent direct anterior screw fixation for a recent fracture (< 6 months postinjury [129 patients]) or remote (≥ 18 months postinjury [18 patients]) Type II (138 cases) or III (nine cases) odontoid fractures at the University of Utah (94 patients) and National Institute of Traumatology in Budapest, Hungary (53 patients) between 1986 and 1998 are included in this study (mean follow-up period 18.2 months). Data obtained from clinical examination, review of hospital charts, operative findings, and imaging studies were used to analyze the surgery-related results in these patients.

In patients with recent fractures there was an overall bone fusion rate of 88%. The rate of anatomical bone fusion of recent fractures was significantly (p ≤ 0.05) higher in fractures oriented in the horizontal and posterior oblique direction (as compared with anterior oblique), but this finding was independent (p ≥ 0.05) of age, sex, number of screws placed (one or two), and the degree or the direction of odontoid displacement. In patients with remote fractures there was a significantly lower rate of bone fusion (25%). Overall, complications related to hardware failure occurred in 14 patients (10%) and unrelated to hardware in three patients (2%). There was one death (1%) related to surgery.

Conclusions

Direct anterior screw fixation is an effective and safe method for treating recent odontoid fractures (< 6 months postinjury). It confers immediate stability, preserves C1–2 rotatory motion, and achieves a fusion rate that compares favorably with alternative treatment methods. In contradistinction, in patients with remote fractures (≥ 18 months postinjury) a significantly lower rate of fusion is found when using this technique, and these patients are believed to be poor candidates for this procedure.

Effect of carbohydrate ingestion on glycogen resynthesis in human liver and skeletal muscle, measured by (13)C MRS

This study investigated the effect of carbohydrate (CHO) ingestion on postexercise glycogen resynthesis, measured simultaneously in liver and muscle (n = 6) by (13)C magnetic resonance spectroscopy, and subsequent exercise capacity (n = 10). Subjects cycled at 70% maximal oxygen uptake for 83 +/- 8 min on six separate occasions. At the end of exercise, subjects ingested 1 g/kg body mass (BM) glucose, sucrose, or placebo (control). Resynthesis of glycogen over a 4-h period after treatment ingestion was measured on the first three occasions, and subsequent exercise capacity was measured on occasions four through six. No glycogen was resynthesized during the control trial. Liver glycogen resynthesis was evident after glucose (13 +/- 8 g) and sucrose (25 +/- 5 g) ingestion, both of which were different from control (P < 0.01). No significant differences in muscle glycogen resynthesis were found among trials. A relationship between the CHO load (g) and change in liver glycogen content (g) was evident after 30, 90, 150, and 210 min of recovery (r = 0.59-0. 79, P < 0.05). Furthermore, a modest relationship existed between change in liver glycogen content (g) and subsequent exercise capacity (r = 0.53, P < 0.05). However, no significant difference in mean exercise time was found (control: 35 +/- 5, glucose: 40 +/- 5, and sucrose: 46 +/- 6 min). Therefore, 1 g/kg BM glucose or sucrose is sufficient to initiate postexercise liver glycogen resynthesis, which contributes to subsequent exercise capacity, but not muscle glycogen resynthesis.