Hwan Mo Lee

Unilateral Versus Bilateral Pedicle Screw Fixation in Lumbar Spinal Fusion

STUDY DESIGNnA prospective study of 87 patients who underwent unilateral or bilateral pedicle screw fixation.nnnOBJECTIVESnTo determine whether unilateral pedicle screw fixation is comparable with bilateral fixation in one- or two-segment lumbar spinal fusion.nnnSUMMARY OF BACKGROUND DATAnClinical results for unilateral variable screw placement instrumentation in isolated L4-L5 fusion have been reported to be as good as those for bilateral instrumentation. However, unilateral instrumentation may not be recommended for multilevel fusion.nnnMETHODSnEighty-seven patients were assigned to either unilateral (n = 47) or bilateral (n = 40) pedicle screw instrumentation groups. Two kinds of pedicle screw system (Moss Miami, DePuy, Warsaw, IN, and Steffee VSP, AcroMed, Cleveland, OH) were used. Operating time, blood loss, duration of hospital stay, clinical outcomes, fusion rates, complication rates, and medical expenses were studied and tested with independent sample t test and chi2 test.nnnRESULTSnThere were no significant differences between the two groups in blood loss, clinically satisfactory results, fusion rate, and complication rate. There were significant differences in duration of operating time, duration of hospital stay, and medical expenses. The number of fusion segments or kinds of instrumentation did not affect the fusion rate or clinical outcomes.nnnCONCLUSIONSnUnilateral pedicle screw fixation was as effective as bilateral pedicle screw fixation in lumbar spinal fusion independent of the number of fusion segments (one or two segments) or pedicle screw systems. Based on the results of this study, unilateral fixation could be used in two-segment lumbar spinal fusion.

Validation in the Cross-Cultural Adaptation of the Korean Version of the Oswestry Disability Index

Disability questionnaires are used for clinical assessment, outcome measurement, and research methodology. Any disability measurement must be adapted culturally for comparability of data, when the patients, who are measured, use different languages. This study aimed to conduct cross-cultural adaptation in translating the original (English) version of the Oswestry Disability Index (ODI) into Korean, and then to assess the reliability of the Korean versions of the Oswestry Disability Index (KODI). We used methodology to obtain semantic, idiomatic, experimental, and conceptual equivalences for the process of cross-cultural adaptation. The KODI were tested in 116 patients with chronic low back pain. The internal consistency and reliability for the KODI reached 0.9168 (Cronbachs alpha). The test-retest reliability was assessed with 32 patients (who were not included in the assessment of Cronbachs alpha) over a time interval of 4 days. Test-retest correlation reliability was 0.9332. The entire process and the results of this study were reported to the developer (Dr. Fairbank JC), who appraised the KODI. There is little evidence of differential item functioning in KODI. The results suggest that the KODI is internally consistent and reliable. Therefore, the KODI can be recommended as a low back pain assessment tool in Korea.

Deep vein thrombosis after major spinal surgery: incidence in an East Asian population.

STUDY DESIGNnA prospective study of 313 patients who underwent major spinal surgery.nnnOBJECTIVESnTo determine the incidence of deep vein thrombosis after major spinal surgery in an east Asian population without antithrombotic prophylaxis.nnnSUMMARY OF BACKGROUND DATAnSpinal surgery has been associated with few thrombotic complications (2-14%) compared with other reconstructive surgeries (20-70%). It has also been well documented that the incidence of deep vein thrombosis in east Asians (10%) is lower than in westerners (20-70%) in total joint replacements. There has been no previous report on the incidence of deep vein thrombosis after reconstructive spinal surgery in east Asians.nnnMETHODSnThree hundred thirteen patients who underwent major spinal surgery were evaluated prospectively. All patients were examined with duplex ultrasonography assessments of both lower extremities. No specific antithrombotic prophylaxis were used in any patients before or after surgery.nnnRESULTSnThere were four patients with positive findings of deep vein thrombosis on duplex ultrasonography, and there was only one with clinically symptomatic deep vein thrombosis. The overall incidence of thrombotic complications was 1.3%, and the incidence of symptomatic deep vein thrombosis was 0.3%.nnnCONCLUSIONnConsidering the low rate of deep vein thrombosis, routine screening and prophylaxis for deep vein thrombosis appears unwarranted in east Asians before or after major spinal surgery.

Sacroiliac joint tuberculosis : Classification and treatment

The authors treated 16 patients with tuberculosis of the sacroiliac joint. Twelve were treated surgically and four were treated conservatively. The clinical symptoms were buttock and low back pain in all patients, and most had difficulty walking (68.6%) and had radicular pain in their lower limbs (50%). Of the 16 patients, four (15%) had associated tuberculous spondylitis, six (37.5%) had an abscess in the gluteal region, and two (12.5%) had an abscess in the inguinal region. The diagnosis was proven by pathologic specimen in 12 patients and by clinical symptoms, laboratory data, and radiologic findings in the remaining four patients. The authors classified tuberculous sacroiliitis into four types based on the clinical and radiologic findings. Types 1 and 2 were treated conservatively with chemotherapy alone, whereas Types 3 and 4 were treated with surgery and chemotherapy. Healing occurred and was evident in patients who had curettage and arthrodesis (Types 3 and 4) at a mean of 20.8 months, which was comparable with healing in the patients who had chemotherapy alone that occurred at a mean of 23.5 months (Types 1 and 2). The authors suggest that the new classification will be helpful in determining the therapeutic plan of tuberculous sacroiliitis.

Comparative analysis of clinical outcomes in patients with osteoporotic vertebral compression fractures (OVCFs): conservative treatment versus balloon kyphoplasty

BACKGROUND CONTEXTnMost osteoporotic vertebral compression fractures (OVCFs) can be treated conservatively. Recently, kyphoplasty has become a common treatment for painful osteoporotic compression fractures and has shown numerous benefits, such as early pain control and height restoration of the collapsed vertebral body. In spite of being a simple procedure, numerous complications related to kyphoplasty have been reported. Moreover, there is limited evidence to support its superiority.nnnPURPOSEnTo compare the clinical outcomes of patients with OVCF according to different treatment modalities and identify clinical risk factors related to failure of conservative treatment of OVCF.nnnSTUDY DESIGNnA prospective study consisting of a review of case report forms. PATIENTS SAMPLE: We prospectively enrolled 259 patients who had one or two acute painful OVCFs confirmed by magnetic resonance imaging. All patients were treated conservatively in the initial 3 weeks. Kyphoplasty was performed in 91 patients who complained of sustained back pain and disability in spite of conservative treatment for the initial 3 weeks.nnnOUTCOME MEASURESnPain score using visual analog scale (VAS) and the Oswestry Disability Index (ODI).nnnMETHODSnParticipants were stratified according to age, sex, level and number of fractures, bone mineral density, body mass index (BMI), collapse rates, and history of spine fractures. Pain scores using VASs were assessed at 1 week and at 1, 3, 6, and 12 months.nnnRESULTSnA total of 259 patients were enrolled, and 231 patients (82 of 91 patients in the kyphoplasty group [KP] and 149 of 168 patients in the conservative treatment group) completed the 1-year follow-up. About 65% of patients were treated successfully with conservative treatment. Risk factors for failure of 3 weeks of conservative treatment were older age (older than 78.5 years), severe osteoporosis (t score less than -2.95), overweight (BMI more than 25.5), and larger collapse rates (more than 28.5%). There were significant reductions in VAS and ODI scores in both groups at each follow-up assessment. At the first month, better clinical results were observed in KP. However, there were no significant differences in outcome measures between the two groups at 3, 6, or 12 months. Thirteen subsequent compression fractures (five in KP and eight in the conservative treatment group) occurred during the 1-year follow-up period.nnnCONCLUSIONnBoth treatments of OVCF showed successful clinical results at the end of the 1-year follow-up period. Kyphoplasty showed better outcomes in the first month only. Given these results, prompt kyphoplasty should not be indicated in the case of a patient with OVCF that has no risk factors for failure with conservative treatment. Rather, a trial of conservative, 3-week treatment would be beneficial.

The effect of age on cervical sagittal alignment: normative data on 100 asymptomatic subjects.

Study Design. Retrospective study. Objective. To determine age-related changes in cervical sagittal alignment using whole-spine standing radiographs in asymptomatic adults. Summary of Background Data. Modern surgical techniques have emphasized the importance of maintaining proper sagittal alignment. But there is a paucity of literature investigating age-related changes in cervical sagittal alignment. Methods. One hundred healthy unoperated adults who were free of spinal problems obtained whole-spine standing radiographs. They consisted of 2 groups divided by age: those in their 20s and those older than 60 years. Each group had an equal ratio of males and females. Distances from C2 as well as C7 plumb lines to the following points were measured: thoracic and lumbar apex as well as the posterior superior corner of the S1 vertebral body. In addition, Cobb angles for C0–C2, C2–C7, thoracic kyphotic angle, lumbar lordotic angle, and T1 sagittal slope angles were measured. Results. The distance between the C2 and C7 plumb lines did not vary with age. The thoracic apex shifted caudally from T6 in the younger group to T7 in the older group. The most common lumbar apex was L4 for both groups. The distance from C2, as well as C7 plumb lines to the posterior superior corner of the S1 vertebral body, as well as the thoracic apex increased significantly in the older group. On the contrary, the distance from the 2 plumb lines to the lumbar apex decreased in the older group. Also, C2–C7 angle increased and T1 sagittal slope angle decreased in the older group compared with the younger group. However, no difference was found for the other Cobb angles between the 2 groups. Conclusion. The distances between the plumb lines from C2 and C7 were maintained but C2–C7 sagittal angle increased with aging. Level of Evidence: 4

The effects of ketorolac injected via patient controlled analgesia postoperatively on spinal fusion.

Lumbar spinal fusions have been performed for spinal stability, pain relief and improved function in spinal stenosis, scoliosis, spinal fractures, infectious conditions and other lumbar spinal problems. The success of lumbar spinal fusion depends on multifactors, such as types of bone graft materials, levels and numbers of fusion, spinal instrumentation, electrical stimulation, smoking and some drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs). From January 2000 to December 2001, 88 consecutive patients, who were diagnosed with spinal stenosis or spondylolisthesis, were retrospectively enrolled in this study. One surgeon performed all 88 posterolateral spinal fusions with instrumentation and autoiliac bone graft. The patients were divided into two groups. The first group (n=30) was infused with ketorolac and fentanyl intravenously via patient controlled analgesia (PCA) postoperatively and the second group (n=58) was infused only with fentanyl. The spinal fusion rates and clinical outcomes of the two groups were compared. The incidence of incomplete union or nonunion was much higher in the ketorolac group, and the relative risk was approximately 6 times higher than control group (odds ratio: 5.64). The clinical outcomes, which were checked at least 1 year after surgery, showed strong correlations with the spinal fusion status. The control group (93.1%) showed significantly better clinical results than the ketorolac group (77.6%). Smoking had no effect on the spinal fusion outcome in this study. Even though the use of ketorolac after spinal fusion can reduce the need for morphine, thereby decreasing morphine related complications, ketorolac used via PCA at the immediate postoperative state inhibits spinal fusion resulting in a poorer clinical outcome. Therefore, NSAIDs such as ketorolac, should be avoided after posterolateral spinal fusion.

Facet joint degeneration of the cervical spine: a computed tomographic analysis of 320 patients.

Study Design. Retrospective study. Objective. To determine the frequency of facet arthrosis according to age, sex, and cervical level. In addition, we propose and evaluate a new grading system for cervical facet degeneration. Summary of Background Data. Cervical facets can play an important role in symptomatology. However, there is only one computed tomographic grading system for cervical facet joints. Methods. From January 2003 to January 2012, 1944 patients underwent computed tomography of the cervical spine in our institution. We randomly selected 40 males and 40 females from each of the following age groups: 40 to 49, 50 to 59, 60 to 69, and 70 to 79, such that we had a total of 320 patients. We then graded the degree of arthrosis of the facet joints from C2 to C7 on the axial, sagittal, or coronal images according to 4 grades. These categories were: grade I, normal; grade II, degenerative changes including joint space narrowing, cyst formation, small osteophytes without joint hypertrophy seen; grade III, facet joint hypertrophy from large osteophytes without fusion; and grade IV, bony fusion of the facet joint. The intra- and interobserver reliabilities for the grading system were calculated using reliability statistics by intraclass correlation. Results. Facet arthrosis is common with older patients and at C2–C3, C3–C4, and C4–C5. Facet arthrosis was more common on the left side and in males. Greater than grade III facet joint arthrosis was common in patients older than 60 and at C2–C3, C3–C4, and C4–C5. The reliability statistics by intraclass correlation for the grading system was 0.878 for the intraobserver reliability and 0.869 for the interobserver reliability. Conclusion. It seems that upper cervical levels are more likely to degenerate and to have more advanced degrees of degeneration than the lower cervical levels. As expected, age correlates with worsening degeneration. The proposed computed tomographic grading system for cervical facet arthrosis seemed to be reliable. Level of Evidence: 4

Pelvic obliquity in neuromuscular scoliosis: radiologic comparative results of single-stage posterior versus two-stage anterior and posterior approach.

Study Design. Retrospective comparative study (Level III). Objective. To compare the operative results of posterior fusion and a 2-stage anterior L5-S1 fusion followed by posterior fusion in neuromuscular scoliosis patients with significant pelvic obliquity (PO). Summary of Background Data. PO in neuromuscular scoliosis is common and a challenging problem that affects proper sitting balance, necessarily addressing the deformity and proper maintenance of the correction. Methods. A total of 54 patients with neuromuscular scoliosis and significant PO (>10°) were divided into 2 groups. Group 1 (n = 24) was operated on for posterior fusion and pelvic fixation. Group 2 (n = 30) included patients who were subjected to a first-stage procedure consisting of a lumbosacral junction release and fusion through a midline retroperitoneal approach and then a second-stage procedure of posterior fusion and pelvic fixation. Parameters measured included length of the follow-up, number of fusion levels, age at operation, forced vital capacity, operative time, estimated blood loss, and postoperative complications. Radiologic parameters measured before surgery, after surgery at the time of discharge, and at a final follow-up included Cobb angle, T1 translation, sitting pelvic obliquity (PO) in the frontal plane, C7 plumb line, thoracic kyphosis, lumbar lordosis, and sacral inclination angle in the sagittal plane. Results. The correction of scoliosis was similar in both groups. The preoperative PO averaged 19.5° in Group I and 22.9° in Group II (P = 0.22), which corrected after surgery to 9.7° versus 7.4° (P = 0.23), respectively. Group II correction progressively improved significantly compared to Group I (7.0° vs. 11.6° at P = 0.046) at the latest follow-up. A 40.6% correction (mean correction = 7.9) in sitting PO in Group I compared to 70.7% correction (mean correction = 5.9°) in Group II was observed (P = 0.004). The average loss of correction of PO at the final follow-up was lesser in group II, but not statistically significant (P = 0.07). Conclusion. Anterior fusion of the lumbosacral junction followed by posterior fusion provides superior correction and maintenance of PO in patients with neuromuscular scoliosis.

Perioperative complication and surgical outcome in patients with spine metastases: Retrospective 200-case series in a single institute

OBJECTIVEnMetastatic spinal disease requires a multidisciplinary approach with advanced surgical techniques which improve longevity and the quality of life. The purpose of this study is to compare the surgical outcomes and perioperative complications and mortality among en bloc, debulking, and palliative surgeries in patients with spinal metastasis.nnnMETHODSnFrom 2005 to 2010, 200 patients who underwent surgical treatment for spinal metastases were enrolled retrospectively. Clinical analysis included primary cancer type, survival following the diagnosis of cancer, postoperative survival, Tokuhashi score, postoperative functional status, postoperative complications and mortality depending on the surgery type. Enrolled patients were divided into 3 groups: en bloc excision, debulking curettage, and palliative surgery. Surgical outcomes including perioperative complication and mortality were compared based on the surgery type.nnnRESULTSnThe mean age was 59.9 years (range 21-87). The major types of primary cancer were lung (42 cases), liver (27 cases), and colorectal cancer (27 cases). 62 surgeries (31.0%) were en bloc excisions, 82 (41.0%) were debulking, and 56 (28.0%) were palliative operations. The mean Tokuhashi score was 9.2±3.3 in the en bloc group, 7.2±3.0 in the debulking group and 8.2±2.6 in the palliative group (p=0.001, ANOVA). Mean postoperative survivals were 17.9±22.1 months in the en bloc group, 7.0±11.7 months in the debulking group and 8.5±10.8 months in the palliative group (p=0.022, ANOVA). There were 8 (12.9%) postoperative complications in the en bloc group, 17 (20.7%) in the debulking group, and 8 (14.3%) in the palliative group (p=0.016, chi-square). Three patients (4.8%) in the en bloc group had multiple complications, as did 5 (6.1%) in the debulking group and 2 (3.6%) in the palliative group (p=0.925, chi-square). Among 21 total perioperative deaths, 6 (28.6%) were in the en bloc group, 10 (47.6%) in the debulking group, and 5 (23.8%) in the palliative group (p=0.618, chi-square).nnnCONCLUSIONnPostoperative complications were most common in the debulking group compared to the en bloc and palliative groups, despite the fact that there were no differences in the improvement of neurologic deficits after surgery. Therefore, selecting the proper surgery based on the patients symptoms and neurologic status is of great significance in the planning stage of the surgery.