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J Kostuik

Publications and source records attributed to J Kostuik.

9 recordsLinked to original sources
PubMed2000

Relative effectiveness of electrically- vs mechanically-elicited EMGs in detecting pedicle wall perforation and surgically-induced nerve root damage.

Electrical stimulation of a pedicle hole and screw with recording EMGs from the lower extremities has been used as an indicator in detecting perforations of the pedicle. Mechanically-elicited EMGs are reported to be sensitive to mechanical irritation of nerve roots. This study analyzed the sensitivity of the data elicited by two EMG monitoring methods in the presence of a neurologic deficit caused by a malpositioned screw to determine the relative effectiveness of electrically- vs mechanically-elicited EMGs in detecting pedicle wall perforations and nerve root damage in patients undergoing spinal surgery utilizing transpedicular instrumentation. One hundred and four surgeries were monitored using the two EMG methods. Six hundred and fifty-four pedicle holes were prepared and 650 placed pedicle screws were electrically tested. Mechanically-elicited EMGs were monitored from a total of 618 muscles. Electrically-elicited EMGs showed a 62% true-positive rate and a 0.2% false-negative rate in detecting pedicle wall perforations. None of the patients who initially demonstrated abnormal electrically-elicited EMGs demonstrated any post-operative neurologic problems due to an incorrect screw placement. Only one patient who had abnormal mechanically-elicited EMGs during the procedures related to instrumentation developed new L4 radiculopathy immediately post-operatively which was consistent with the level of mechanically-elicited EMGs. Mechanically-elicited EMGs showed a 100% true-positive rate for nerve root irritation and a 3.5% false-negative rate in detecting pedicle wall perforations by malpositioned screw. In conclusion, although mechanically-elicited EMGs were an insensitive technique in detecting a perforation of the pedicle, mechanically-elicited EMGs were more beneficial than electrically-elicited EMGs in detecting the risk of nerve root irritation.

Adult↗
PubMed1998

A comparison of impedance and electromyogram measurements in detecting the presence of pedicle wall breakthrough.

STUDY DESIGN: A prospective comparison of impedance measurements, electrically elicited electromyograms, and mechanically elicited electromyograms to detect pedicle wall breakthrough. OBJECTIVE: To determine whether impedance measurements are as sensitive as electromyogram measurements in evaluating pedicle wall breakthrough. SUMMARY OF BACKGROUND DATA: In a previous animal study, impedance values in pedicle screw placement were tested, to determine a baseline value for an intact pedicle. If pedicle wall breakthrough occurred, it was thought that the impedance values should be significantly lower. METHODS: Impedance measurements, electrically elicited electromyograms and mechanically elicited electromyograms were recorded in 20 patients undergoing surgery for spinal degeneration, using previously described standard protocol. Analysis of variance statistics were used to evaluate the data. RESULTS: Impedance values for the pedicle holes varied from 500 ohms to 31,000 ohms. There was no correlation between these values and those of the two pedicles in which breaches were detected on visual inspection. Electrically elicited electromyograms detected the breakthroughs in both pedicles, whereas mechanically elicited electromyograms detected one of the breakthroughs. CONCLUSIONS: Electrically elicited electromyograms were more sensitive in detecting pedicle wall breakthrough than were impedance measurements. This may be because of the inability to ascribe absolute impedance values to human pedicle bone caused by the wide variability in bone quality.

Adult↗
PubMed1996

Does intraoperative blood loss affect antibiotic serum and tissue concentrations?

OBJECTIVE: To determine the effect of intraoperative blood loss on prophylactic cefazolin and gentamicin serum and tissue concentrations. DESIGN: A prospective study of elective spinal instrumentation surgical procedures with an expected large blood loss. SETTING: Tertiary care, inner-city university hospital. PATIENTS: Eleven adult patients who underwent an elective surgical procedure that involved spinal instrumentation. INTERVENTION: Standard perioperative administration of a combination of cefazolin and gentamicin. Serum and tissue samples were obtained consecutively throughout the surgical procedure. MAIN OUTCOME MEASURES: The effect of intraoperative blood loss on serum and tissue cefazolin and gentamicin concentrations and their pharmacokinetics. RESULTS: At the time of the incision, serum cefazolin concentrations were greater than tissue concentrations (P = .07). A mean dose of 1.8-mg/kg gentamicin yielded low or nontherapeutic serum and tissue gentamicin concentrations. Cefazolin and gentamicin were eliminated from the tissue compartment slower than from the serum compartment (P < .03), while the half-life of cefazolin was significantly (P = .06) longer in the tissue compartment. The volume of distribution of cefazolin was normal (ie, 12.5 L), while the volume of distribution of gentamicin was 5-fold greater than expected. At 60 minutes after the incision, blood loss correlated with cefazolin tissue concentrations (r = -0.66, P = .05). Blood loss correlated with the change in tissue antibiotic concentrations for cefazolin (r = 0.73, P = .04). In addition, the clearance of gentamicin from the tissues correlated with blood loss (r = 0.82, P = .01). CONCLUSIONS: Based on measured pharmacokinetic values, additional doses of cefazolin should be administered when the operation exceeds 3 hours and blood loss is greater than 1500 mL. Doses of gentamicin greater than 1.8 mg/kg should be administered more than 30 minutes prior to the surgical incision.

Adult↗
PubMed1996

Evaluation of pedicle screw insertion monitored by intraoperative evoked electromyography.

The insertion of pedicle screws monitored by evoked electromyography (EMG) was prospectively evaluated in the 132 consecutive patients. The technique involved constant-voltage stimulation and was statistically evaluated at both the arbitrary 20- and 40-V settings. The patients were postoperatively evaluated clinically and radiographically. Computed tomography (CT) scanning was performed for new neurologic deficits. Results were divided into three groups: type 1, a negative EMG response; type 2, a positive EMG response, but no corrective action taken; and type 3, a positive EMG response and corrective action undertaken. Nonparametric statistics were used to evaluate the results at both the 20- and 40-V settings. In the type 3 group, in which corrective action was undertaken, there were no neurologic injuries or screw removals, a statistically significant result. Looking at the two intensity levels, at 20- and 40-V settings, there were no statistically significant differences in the three classifications at either intensity level. We concluded the evoked EMG for monitoring pedicle screw insertion is an efficacious adjunct. A positive response at < 20 V with the constant-voltage technique warrants corrective action.

Adult↗
PubMed1984

Arthrodesis for failed arthroplasty of the hip.

The results of Girdlestone arthroplasty after failure of total hip arthroplasty have been found to be functionally poor in the physiologically young patient. The authors have evaluated 14 patients who were treated by hip arthrodesis following repeated failed arthroplasty. The average number of previous procedures was 2.6. Seven were infected prior to arthrodesis. A modified A.O. technique was used in all cases and was followed by hip spica immobilization. The average age of the patients was 38 years. All but one were men. Thirteen of the patients healed their arthrodesis primarily. Pain relief was excellent and most patients were able to return to their original jobs, in contrast to the results in patients with Girdlestone arthroplasty. Osteotomy or arthrodesis is preferred to total hip arthroplasty in the young, active patient with unilateral osteoarthritis. Arthrodesis is also possible and has a high rate of functional success after failed arthroplasty, infected or noninfected.

Acetabulum↗
PubMedDate not supplied

The application of pelvic pins in halo-pelvic distraction. An anatomic study.

The application of the pelvic hoop for halo-pelvic distraction, as described by O'Brien, has led to serious abdominal complications. A study of mature Caucasian pelves as compared to the smaller East Indian pelves has shown that in the larger pelvis, when the gluteal tubercle and posterior superior iliac spine are used as landmarks, as advocated by O'Brien, the pins will invariably pass within the soft tissue elements of the inner pelvis instead of being entirely within the bony ilium, as O'Brien noted in the Chinese pelves. On the basis of pelvic measurements and observations, the authors recommend an open technique for passage of the pins.

Adult↗