Biomedical subjects

Yongjung Kim

Publications and source records attributed to Yongjung Kim.

4 recordsLinked to original sources

PubMed2005

Apical sublaminar wires versus pedicle screws--which provides better results for surgical correction of adolescent idiopathic scoliosis?

STUDY DESIGN: The results of correction for adolescent idiopathic scoliosis (AIS) were compared using apical sublaminar wires versus pedicle screws. OBJECTIVE: To compare comprehensively the 2-year minimum postoperative results of posterior correction and spinal fusion using translational correction through either hybrid hook/sublaminar wire/pedicle screw constructs versus in situ rod-contouring correction with pedicle screw constructs in the treatment of AIS at 2 institutions. SUMMARY OF BACKGROUND DATA: Despite the reports of satisfactory correction of scoliotic curves by both apical (sublaminar wire) instrumentation and apical pedicle screw instrumentation, to our knowledge, no reports on the comprehensive comparison of hybrid (hook/sublaminar wire/pedicle screw) instrumentation versus segmental pedicle screw instrumentation exist. METHODS: A total of 50 patients with AIS at 2 institutions who underwent posterior spinal fusion with sublaminar wire (25 patients) or pedicle screw (25) constructs were sorted and matched according to 4 criteria: (1) similar age at surgery (14.2 years in the sublaminar wire and 14.4 in the pedicle screw group, P = 0.72); (2) similar number of fused vertebrae (11.4 in the sublaminar wire and 11.8 in the pedicle screw group, P = 0.36); (3) similar operative methods; and (4) identical Lenke curve types and similar preoperative major curve measurements (63.5 degrees in the sublaminar wire and 59.5 degrees in the pedicle screw group, P = 0.42). Patients were evaluated preoperatively, immediately postoperatively, and at 2-year follow-up according to radiographic changes in curve correction, operating time, intraoperative blood loss, implant costs, and the Scoliosis Research Society patient questionnaire (SRS-24) scores. RESULTS: After surgery, average major curve correction was 67.4% in the sublaminar wire and 68.1% in the pedicle screw group (P = 0.56). At 2-year follow-up, loss of the major curve correction was 4.6% in the sublaminar wire compared to 5.1% in the pedicle screw group (P = 0.79). Postoperative global coronal and sagittal balance were similar in both groups. No significant difference was found in the average number of levels fused from the distal end vertebra (1.48 in the sublaminar wire and 0.64 in the pedicle screw group, P = 0.21). Operating time averaged 350 minutes in the sublaminar wire and 357 in the pedicle screw group (P = 0.86). Intraoperative blood loss was significantly different in both groups (1791 +/- 816 mL in the sublaminar wire and 824 +/- 440 mL in the pedicle screw group) (P = 0.0003). Average implant cost in the sublaminar wire group (16.0 fixation points; 8,341 US dollars) was significantly lower than that of the pedicle screw group (17.1 fixation points; 13,462 US dollars) (P < 0.0001). Postoperative 2-year SRS-24 scores were similar in both groups (sublaminar wire = 107.3, pedicle screw = 103.5, P = 0.19). There were no neurologic or visceral complications related to sublaminar wire or pedicle screw instrumentation and no reoperations at a minimum 2-year follow-up. CONCLUSIONS: Apical sublaminar wire and pedicle screw instrumentation both offer similar major curve correction with similar fusion lengths without neurologic problems in the operative treatment of AIS. Although more expensive, pedicle screw constructs had significantly less blood loss and slightly shorter fusion lengths than the sublaminar wire constructs.

Adolescent↗

PubMed2005

Perioperative halo-gravity traction in the treatment of severe scoliosis and kyphosis.

STUDY DESIGN: A retrospective analysis of patients that underwent perioperative halo-gravity traction as an adjunct to modern instrumentation methods in the treatment of severe scoliosis and kyphosis. OBJECTIVE: To review the clinical and radiographic results of perioperative halo-gravity traction in several time periods. SUMMARY OF BACKGROUND DATA: Few reports to our knowledge review the use of perioperative and intraoperative halo-gravity traction in this patient population. METHODS: A total of 33 patients with severe operative scoliosis, kyphoscoliosis, or kyphosis were studied based on hospital records, standing pretreatment, traction (before anterior/posterior fusion), postoperative (each stage), and final radiographs. Patients were analyzed by age at date of examination (range, 2-20 years; mean, 13.8 years), gender (18 male, 15 female), major coronal curve magnitude (range, 22 degrees-158 degrees; average, 84 degrees), major compensatory coronal curve magnitude (range, 8 degrees-123 degrees; average, 51 degrees), major sagittal curve magnitude (range, 13 degrees-143 degrees; average, 78 degrees), traction protocol, and procedure type. Halo-traction-related, short- and long-term complications were noted in each case. RESULTS: The major coronal curve reduced 38 degrees or 46% after posterior spinal fusion compared to pretreatment radiographs. At an average of 44 months radiographic follow-up (range, 24-107 months), the loss of correction averaged 7 degrees for major coronal curves and 4 degrees of thoracic kyphosis. Clinical complications were noted in the perioperative and long-term time periods. CONCLUSIONS: The treatment of severe scoliosis can be very challenging despite the benefits of modern instrumentation methods, especially if there is a significant kyphosis or a history of intraspinal pathology. Halo-gravity traction is a safe, well-tolerated method of applying gradual, sustained traction to maximize postoperative correction in this difficult population. There were no permanent neurologic deficits in this series.

Adolescent↗

PubMed2004

Late complications of adult idiopathic scoliosis primary fusions to L4 and above: the effect of age and distal fusion level.

UNLABELLED: STUDY DESIGN A retrospective analysis of primary cases of adult idiopathic scoliosis treated with long instrumented fusions from the thoracic spine proximally to segments that range from T11 to L4 distally. OBJECTIVE: To analyze whether patients requiring revision surgery had lower postoperative SRS-24 scores; age >or=40 years correlated with higher rates of revision surgery; disc degeneration below the fusion occurred more commonly with a more distal lowest instrumented vertebra or older patient age (>or=40 years); and whether smokers had higher rates of major complications or revision surgery. SUMMARY OF BACKGROUND DATA: Few reports describe complications related to primary long fusions using modern 2+ rods, hook/pedicle screw instrumentation methods in the treatment of adult idiopathic scoliosis. METHODS: Sixty-seven patients were analyzed with an average age of 38.8 years (range 21-61 years). The average clinical follow-up was 7.8 years (range 2-16 years): 42 patients had >5 years follow-up, including 23 patients with >10 years follow-up. Patients were categorized by age (< or >or=40 years) and level of the lowest instrumented vertebra (T11-L2 vs. L3-L4). Upright radiographs and postoperative SRS-24 questionnaires from the latest follow-up date were analyzed. RESULTS: Patients requiring revision surgery had lower total score (average 72.0) than those that did not (total score = 94.2; P = 0.01). More specifically, patients with pseudarthrosis had lower total scores (average 74.7) than those without (average total score = 93.5; P = 0.02). When analyzing age, there were similar rates of pseudarthrosis, but higher rates of transition syndrome (2) and sagittal/coronal imbalance (1 each) in patients >or=40 years. Subsequent distal disc degeneration did not correlate significantly with more distal lowest instrumented vertebra or older patient age. Smokers did not have higher rates of major complications or revision surgery than nonsmokers. CONCLUSIONS: Patients with adult idiopathic scoliosis and long fusions had similar pseudarthrosis rates, but higher rates of transition syndrome when lowest instrumented vertebra was L3-L4 relative to levels T11-L2. When categorized by age, complication rates were similar in each group. Patients with pseudarthroses or other diagnoses requiring revision surgery had lower SRS-24 total scores than those without (P = 0.02 and P = 0.01, respectively).

Adult↗

PubMed2002

Can triggered electromyograph thresholds predict safe thoracic pedicle screw placement?

STUDY DESIGN: A prospective clinical study of thoracic pedicle screws monitored with triggered electromyographic testing. OBJECTIVE: To evaluate the sensitivity of recording rectus abdominis triggered electromyographs to assess thoracic screw placement. SUMMARY OF BACKGROUND DATA: Triggered electromyographic testing from lower extremity myotomes has identified medially placed lumbar pedicle screws. Higher thresholds indicate intraosseous placement because of increased resistance to current flow. Lower thresholds correspond to compromised pedicles with potential for nerve impingement. No clinical study has correlated an identical technique with rectus muscle recordings, which are innervated from T6 to T12. METHODS: A total of 677 thoracic screws were placed in 92 consecutive patients. Screws placed from T6 and T12 were evaluated using an ascending method of stimulation until a compound muscle action potential was obtained from the rectus abdominis. Threshold values were compared both in absolute terms and also in relation to other intrapatient values. RESULTS: Screws were separated into three groups: Group A (n = 650 screws) had thresholds >6.0 mA and intraosseus placement. Group B (n = 21) had thresholds <6.0 mA but an intact medial pedicle border on reexamination and radiographic confirmation. Group C (n = 6) had thresholds <6.0 mA and medial wall perforations confirmed by tactile and/or visual inspection. Thus, 3.9% (27 of 677) of all screws had thresholds <6.0 mA. Only 22% (6 of 27) had medial perforation. Group B screws averaged a 54% decrease from the mean as compared with a 69% decrease for Group C screws (P = 0.0160). There were no postoperative neurologic deficits or radicular chest wall complaints. CONCLUSION: To assess thoracic pedicle screw placement, triggered electromyographic thresholds <6.0 mA, coupled with values 60-65% decreased from the mean of all other thresholds in a given patient, should alert the surgeon to suspect a medial pedicle wall breach.

Action Potentials↗