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Brian Kwon

Publications and source records attributed to Brian Kwon.

11 recordsLinked to original sources
PubMed2006

Radiographic measurement parameters in thoracolumbar fractures: a systematic review and consensus statement of the spine trauma study group.

STUDY DESIGN: Systematic review. OBJECTIVES: To review the various radiographic parameters currently used to assess traumatic thoracolumbar injuries, emphasizing the validity and technique behind each one, to formulate evidence-based guidelines for a standardized radiographic method of assessment of these fractures. SUMMARY OF BACKGROUND DATA: The treatment of thoracolumbar fractures is guided by various radiographic measurement parameters. Unfortunately, for each group of parameters, there has usually been more than 1 proposed measurement technique, thus creating confusion when gathering data and reporting outcomes. Ultimately, this effect results in clinical decisions being based on nonstandardized, nonvalidated outcome measures. METHODS: Computerized bibliographic databases were searched up to January 2004 using key words and Medical Subject Headings on thoracolumbar spine trauma, radiographic parameters, and methodologic terms. Using strict inclusion criteria, 2 independent reviewers conducted study selection, data abstraction, and methodologic quality assessment. RESULTS: There were 18 original articles that ultimately constituted the basis for the review. Of radiographic measurement parameters, 3 major groups were identified, depicting the properties of the injured spinal column: sagittal alignment, vertebral body compression, and spinal canal dimensions, with 14 radiographic parameters reported to assess these properties. CONCLUSIONS: Based on a systematic review of the literature and expert opinion from an experienced group of spine trauma surgeons, it is recommended that the following radiographic parameters should be used routinely to assess thoracolumbar fractures: the Cobb angle, to assess sagittal alignment; vertebral body translation percentage, to express traumatic anterolisthesis; anterior vertebral body compression percentage, to assess vertebral body compression, the sagittal-to-transverse canal diameter ratio, and canal total cross-sectional area (measured or calculated); and the percent canal occlusion, to assess canal dimensions.

Consensus↗
PubMed2006

A review of the 2001 Volvo Award winner in clinical studies: lumbar fusion versus nonsurgical treatment for chronic low back pain: a multicenter randomized controlled trial from the Swedish lumbar spine study group.

The current debate over the efficacy of lumbar fusion for low back pain has not been settled. Fritzell et al published a landmark paper entitled "Lumbar fusion versus nonsurgical treatment for chronic low back pain: a multicenter randomized controlled trial from the Swedish lumbar spine study group." Their goal was to provide objective evidence supporting lumbar fusion. While it was well designed and important to our knowledge base, it has limitations. We set out to review their work in an unbiased yet critical manner. Our goals are to summarize the strengths and weaknesses of the paper, place it in the context of current knowledge, and highlight its significance for present-day practice and research. From technical and study design perspectives, Fritzell et al were able to validate the use of lumbar fusion for the treatment of low back pain. However, their use of "usual nonoperative" care and nonspecific definition of low back pain precluded a truly genuine comparison of operative and nonoperative groups. We commend the Swedish lumbar spine study group and their remarkable efforts; they elevated the sophistication of spine research and spawned many more excellent works to help settle the ongoing controversy on the ideal treatment of low back pain.

Awards and Prizes↗
PubMed2006

Risk factors for delayed extubation after single-stage, multi-level anterior cervical decompression and posterior fusion.

Airway difficulties after single-stage, multilevel anterior and posterior cervical surgery are potentially life-threatening complications. Although extubation delays can occur, overnight intubation can reduce the risk of postoperative airway emergencies. Our protocol was as follows: all patients were kept intubated overnight in an intensive care unit and examined by the intensive care unit staff each morning. Readiness for extubation was based on the cuff-leak test, and extubation done on patients beyond the first postoperative day was considered delayed. Eleven patients were extubated on the first postoperative day (group 1), and 11 extubated beyond day 1 (group 2). No airway emergencies occurred. Patient factors-age, weight, smoking, medical comorbidities, American Society of Anesthesiologist class-were not significantly related to extubation delay. There were no differences between groups in the number of anterior and posterior levels or anterior and posterior operative times. Delayed extubation was significantly related to total operative time (8.2 hours vs. 10.6 hours), volume of crystalloid replacement (3,627 cm3 vs. 6,218 cm3) and intraoperative blood transfused (0.7 units vs. 3.1 units); approaching significance was increased blood loss (1,238 mL vs. 2,820 mL). We have found intraoperative factors-operative time, crystalloid volume, blood loss and replacement-rather than patient characteristics, to be risk factors for delayed extubation. Good communication with anesthesia staff and careful attention to postoperative airway management is essential after single-stage, multilevel anterior cervical decompression and posterior fusion.

Cervical Vertebrae↗
PubMed2006

Comparison of operative and nonoperative treatment for thoracolumbar burst fractures in patients without neurological deficit: a systematic review.

OBJECT: Despite extensive published research on thoracolumbar burst fractures, controversy still surrounds which is the most appropriate treatment. The objective of this study was to evaluate the scientific literature on operative and nonoperative treatment of patients with thoracolumbar burst fractures and no neurological deficit. METHODS: In their search of the literature, the authors identified all possible relevant studies concerning thoracolumbar burst fracture without neurological deficit. Two independent observers performed study selection, methodological quality assessment, and data extraction in a blinded and objective manner for all papers identified during the search. In a synthesis of the literature, the authors obtained evidence for both operative and nonoperative treatments. CONCLUSIONS: There is a lack of evidence demonstrating the superiority of one approach over the other as measured using generic and disease-specific health-related quality of life scales. There is no scientific evidence linking posttraumatic kyphosis to clinical outcomes. The authors found that there is a strong need for improved clinical research methodology to be applied to this patient population.

Back Pain↗
PubMed2005

A prospective study of Autologous Growth Factors (AGF) in lumbar interbody fusion.

BACKGROUND: Numerous preclinical and clinical studies have reported on the use of platelet concentrates to promote tissue healing. The results in spinal fusion applications are limited and controversial. PURPOSE: The purpose of the current prospective clinical cohort study is to assess the effect of Autologous Growth Factors (AGF) on lumbar interbody fusion with specific attention paid to determination of clinical and radiographic outcomes. STUDY DESIGN/SETTING: Prospective clinical study PATIENT SAMPLE: Candidates for anterior-posterior lumbar fusion with diagnosis of degenerative disc disease and/or up to grade I spondylolytic spondylolisthesis based on positive provocative discography. OUTCOME MEASURES: Clinical (visual analogue pain scale/functional outcome assessment) and radiographic outcomes (fusion on computed tomography at 6 months and plain radiographs at 12 and 24 months). METHODS: Thirty-seven patients were assigned to standard anterior-posterior interbody fusion L2-S1 (single or two-level) using iliac crest bone graft (autograft group: 22 patients with 32 levels operated) or allograft combined with autogenous growth factors (AGF group: 15 patients with 25 levels operated). Radiographic outcomes were collected at 6 months postsurgery with computed tomography and at 12 and 24 months with plain radiographs. Pre- and postoperative clinical outcome measures included visual analog scores (VAS) for back and leg pain (0-10), SF-36 scores, and Oswestry disability determination. Average clinical and radiographic follow-up for the autograft group was 24.3+/-5.6 months (12-36 months) and AGF was 25.7+/-7.5 (6-40 months). RESULTS: Fusion incorporation at each end plate was determined at 56% in both autograft and AGF (p=NS) patients based on computed tomography at 6 months with minimal subsidence noted and no direct correlation between the incidence or degree of cage subsidence and bone graft technique. The 12- and 24-month radiographic results confirmed an 85% arthrodesis rate for the autograft patients, whereas the AGF patients had an 89% fusion rate (p=NS). Clinical outcomes were similar for both groups and no significant differences were noted for pain or functional outcome improvements. CONCLUSIONS: AGF combined with an allograft carrier is equivalent in radiographic and clinical outcomes to autograft in one- or two-level lumbar interbody fusion with supplemental posterior fixation and, thus, eliminates any morbidity from iliac crest bone graft harvesting. AGF combined with an appropriate carrier is a reasonable alternative to autograft and expensive bone induction technologies. Further research is still required to examine the optimum carriers, preparation and formulation, and platelet concentrations for this technology.

Adult↗
PubMed2005

Factors predicting motor recovery and functional outcome after traumatic central cord syndrome: a long-term follow-up.

STUDY DESIGN: A prospectively maintained database-generated retrospective review and cross-sectional outcome analysis was performed at a single academic center. OBJECTIVES: To assess the improvement in ASIA motor score (AMS) and secondarily to assess generic health related quality of life (HRQoL) and functional status; correlating these with variables that may predict outcome. SUMMARY OF BACKGROUND DATA: Many variables are potential contributors to motor recovery, patient function, and outcome following cervical trauma. Studies often suffer from low power, short follow-up, heterogeneous cohorts, and use of outcome instruments that are neither valid nor psychometrically sound. METHODS: AMS were collected within 72 hours of the time of injury and again at follow-up by trained examiners. The SF-36 and FIM were administered to all patients at follow-up. RESULTS: AMS improved from a mean of 58.7 at injury to a mean of 92.3 at follow-up. Bowel and bladder continence was reported by 81% while independent ambulation was reported by 86%. Final AMS was positively correlated with the AMS at injury, formal education, and presence of spasticity at follow-up. Functional status (FIM) was positively correlated with higher AMS at injury, formal education, absence of comorbidities, absence of spasticity, and younger age. Generic HRQoL outcomes (SF-36) were improved in individuals with more formal education, fewer comorbidities, absence of spasticity, and anterior column fractures. CONCLUSIONS: Although the majority of patients improve to an AMS between 90 and 100, many have significant disability and are less functional than the general population. Significant predictive variables include the initial motor score, formal education, comorbidities, age at injury, and development of spasticity. An assessment of more than just the motor score is required to obtain an appreciation of the function and outcomes in this population.

Adult↗
PubMed2005

Motor recovery, functional status, and health-related quality of life in patients with complete spinal cord injuries.

STUDY DESIGN: A retrospective cohort with cross- sectional follow-up. OBJECTIVES: The primary objective was to determine motor recovery in patients with complete traumatic spinal cord injury (SCI). Secondary objectives included: 1) determining which factors predict local recovery, 2) assessing functional status using the Functional Independence Measure (FIM), and 3) assessing generic health-related quality of life using the Short Form-36 (SF-36). SUMMARY OF BACKGROUND DATA: Motor recovery following complete SCI has been documented in the literature; however, it has been difficult to interpret: 1) spinal shock is often not addressed; 2) the definition of complete SCI has changed over the last 10 years; and 3) few studies differentiate between local neurologic recovery in the zone of partial preservation and neurologic recovery caudal to the lesion. METHODS: All patients admitted to Vancouver Hospital with a complete SCI between 1994 and 2001 were identified and included in the study if they remained complete following the resolution of spinal shock. Minimum 2-year follow-up consisted of an ASIA motor score, an FIM, and the SF-36. RESULTS: Of 133 patients identified, 94 were eligible and 70 completed follow-up. For the tetraplegic patients, the average ASIA motor score was 11.9 +/- 10.7 on admission and 20.1 +/- 10.8 at follow-up, a change reflecting local recovery only. For the paraplegic patients, the average ASIA motor score was 49.3 +/- 2.4 on admission and 50.6 +/- 1.7 at follow-up. CONCLUSIONS: Motor recovery does not occur below the zone of injury for patients with complete SCI. Varying degrees of local recovery can be expected in tetraplegic individuals.

Adolescent↗
PubMed2005

Outcomes following anterior cervical discectomy and fusion: the role of interbody disc height, angulation, and spinous process distance.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a successful procedure for the degenerative cervical spine. One goal of the fusion is to restore the loss of disc height that results from the degenerative process. Whereas cervical alignment improves with increased disc height, the ideal graft size used for disc space restoration is unknown. Few studies have examined the relationships between these changes in cervical alignment and clinical outcomes. METHODS: All patients underwent a single-level ACDF at the authors' institution. Radiographs at early and final follow-up were examined, and three measurements were made: disc height, disc space angulation, and spinous process distance. These radiographic measurements were correlated with Visual Analog Scales (VASs) for neck and arm pain and Oswestry Disability Index (ODI). RESULTS: There were significant changes in disc height (5.3 vs 7.0 mm) as well as disc space angulation (3.3 degrees vs 0.1 degrees ). Reduction in neck pain VAS score (6.7 vs 3.2) and arm pain VAS score (5.1 vs 2.3) was significant. ODI scores were not statistically different, but improvement of 20.1% was observed. Correlations between radiographic parameters and clinical outcomes were moderate to low, and none was significant. CONCLUSIONS: While restoration of cervical alignment and disc height is important, clinical results are critical in analysis of outcomes following ACDF. We have shown that although clinical outcomes remain good, there does not appear to be any strong correlation with radiographic results. Emphasis on restoration of cervical alignment appears justified, but its influence on clinical outcomes may be overstated.

Adult↗
PubMedDate not supplied

Carrier materials for spinal fusion.

BACKGROUND CONTEXT: The rise in spinal fusion procedures has led to an increase in the available number and variety of bone graft substitutes. As our understanding of the biologic processes that influence bony fusion has improved, appreciation for the role of the carrier material involved in bone grafts has also increased. PURPOSE: The abundance of products available leaves a surgeon with many choices. Knowledge of the current advances will allow for more critical review of the literature and improved decision making when choosing bone graft materials. STUDY DESIGN/SETTING: Review of the English-language literature. METHODS: A critical review of basic science, animal and human studies that investigate the types and role of carrier materials used in spine surgery. RESULTS: The myriad of carrier material available to the spine surgeon is related to the many options in bone graft material. Allograft is an important osteoconductive agent but has its disadvantages especially in regard to disease transmission and immunogenicity. Collagen in various forms is an effective carrier for bone morphogenic protein and autogenous stem cells and can be easily combined with other bone graft materials. Synthetic options include hydroxyapatite and calcium phosphate ceramic materials with different formulations; all are osteoconductive only but can be combined with osteoinductive and/or osteogenic components. Bioabsorbable carriers are effective for use with bone morphogenic protein and can also be used in multiple forms and settings. CONCLUSIONS: Many bone graft carriers exist, and multiple studies have shown their efficacy. It appears that no one carrier is ideal but each situation might influence the choice of one carrier over another.

Animals↗