Jung-Ki Ha

Does preoperative T1 slope affect radiological and functional outcomes after cervical laminoplasty

Study Design. Retrospective comparative study. Objective. To analyze changes in the clinical and radiological factors related to cervical sagittal balance, relative to preoperative T1 slope, in patients with cervical myelopathy after laminoplasty (LP). Summary of Background Data. T1 slope is an important factor that should be considered before LP. However, until now, there have been no studies on how preoperative T1 slope affects the sagittal balance of cervical spine and various functional outcomes after LP. Methods. Seventy-six patients with cervical myelopathy (M:F ratio = 50:26; mean age = 64.7 ± 9.1 yr) underwent a cervical LP and were followed for more than 2 years. Radiological measurements were performed to analyze the following parameters: (1) C2–C7 sagittal vertical axis; (2) T1 slope; (3) C2–C7 lordosis; and (4) thoracic kyphosis. The visual analogue scale, Japanese Orthopedic Association, neck disability index, and 36-Item Short-Form Health Survey were also investigated. Patients were divided into 2 groups according to preoperative T1 slope, with the cutoff value being the median preoperative T1 slope. Changes in clinical and radiological parameters were compared between the preoperative evaluation and final visit. Results. Overall, C2–C7 sagittal vertical axis increased from 21.2 to 24.5 mm (P = 0.004) and C2–C7 lordosis decreased from 13.9° to 10.3° (P = 0.007) postoperatively. The T1 slope did not show any postoperative differences. Preoperative C2–C7 lordosis was larger in the high-T1 group (19.1°) than in the low-T1 group (9.0°). However, postoperative changes in C2–C7 sagittal vertical axis and C2–C7 lordosis did not show any between-group differences. Clinical outcomes (except neck pain) demonstrated overall improvement in both groups. Comparing changes in both groups showed no differences in neck pain, arm pain, neck disability index, or 36-Item Short-Form Health Survey physical component score between groups. Conclusion. Cervical sagittal balance is compromised after cervical LP. However, the degree of aggravation does not correlate with the preoperative T1 slope. Most clinical parameters demonstrate overall improvement regardless of preoperative T1 slope. Level of Evidence: 3

The clinical importance of lumbosacral transitional vertebra in patients with adolescent idiopathic scoliosis.

Study Design. Retrospective review of radiographs. Objective. The objective of this study was to (1) determine the prevalence of lumbosacral transitional vertebra (LSTV) with computed tomography (CT) and (2) correlate LSTV presence with lumbar disc degeneration at each level by magnetic resonance imaging. Summary of Background Data. LSTV is a frequently observed abnormality. Although its prevalence in patients with adolescent idiopathic scoliosis (AIS) has been shown, no studies have yet examined the clinical importance of LSTV in patients with AIS. Methods. This study included 385 consecutive patients who underwent surgery for AIS at a single center. Plain radiographs and CT scans were used to detect LSTV. Disc degeneration was analyzed at the L3–4, L4–5, and L5–S1 disc levels with magnetic resonance imaging. The difference in disc degeneration at each level by the presence of LSTV was also analyzed. The effect of lumbar curve type on the disc degeneration of each level was then determined. To minimize confounding factors, logistic regression analysis was performed. Results. The overall prevalence of LSTV in patients with AIS confirmed by CT scans was 12.2% (47/385). The proportion of grade II or more disc degeneration at the L4–5 level was higher in the LSTV(+) group than in the LSTV(−) group (29.8% vs.19.2%) although it was not statistically significant (P = 0.093). Large lumbar curves showed a positive correlation with disc degeneration at the L5–S1 level (P = 0.022). Conclusion. The prevalence of LSTV in patients with AIS was 12.2%. A trend of early degeneration in L4–5 level discs was found in patients with AIS with LSTV although it was not statistically confirmed. Disc degeneration at the L5–S1 level is related to a large lumbar curve. If patients with AIS with large lumbar curves have LSTV, consideration should be given to stopping the distal fusion at L3 instead of L4. Level of Evidence: 4

The clinical importance of sacral slanting in patients with adolescent idiopathic scoliosis undergoing surgery

BACKGROUND CONTEXT The phenomenon of sacral slanting has not been assessed in patients with adolescent idiopathic scoliosis (AIS). It could be important in determining distal fusion level. PURPOSE The purpose of this study is to clarify sacral slanting and to reveal frequency, character, and clinical importance of sacral slanting in AIS patients who underwent surgery. STUDY DESIGN/SETTING Retrospective review of radiographs. PATIENT SAMPLE The study included 389 patients who underwent surgery for AIS at a single center. OUTCOME MEASURES Slanted angles of sacrum, distal curve types, and postoperative decompensation were assessed in whole spine anteroposterior radiographs. METHODS This was a retrospective case series, which included 389 AIS patients who underwent corrective surgeries. The degree of sacral slanting was defined as the angle between the horizontal line and the upper end plate of the sacrum. Distal curves were classified according to the direction of L4 tilt (L4-left type and L4-right type). The frequency, direction, and relationship with curve types were analyzed descriptively. Postoperative changes of sacral slanting were compared by paired t test. Decompensation by distal fusion level and distal curve types was analyzed descriptively. The p value of less than .05 was considered as statistically significant. RESULTS The frequency of sacral slanting was 19.5% (76 of 389), 29.6% (115 of 389), and 40.6% (158 of 389) by using criteria of 5°, 4°, and 3°, respectively. The 86.7% showed sacral slanting on the left side. The combination of L4-left type with left-sided sacral slanting was the most frequent (124 of 158, 78.7%). Slanted angles were decreased in some cases after surgery. Decompensation in the coronal plane was observed in 2 of 22 patients (9.1%) with a distal fusion level of L4 but in none of the 70 patients with a distal fusion level of L3. CONCLUSIONS Sacral slanting in patients with AIS is a unique and frequently observed finding that has never been researched to date. Most importantly, sacral slanting is a critical consideration in selecting distal fusion level when planning corrective surgery in patients with AIS.

What is the Fate of Pseudarthrosis Detected 1 Year After Anterior Cervical Discectomy and Fusion

Study Design. Retrospective comparative study. Objective. To investigate the consequences and appropriate management of pseudarthrosis after anterior cervical discectomy and fusion (ACDF). Summary of Background Data. Pseudarthrosis is a frequent complication of ACDF and causes unsatisfactory results. Little is known about long-term prognosis of detecting pseudarthrosis 1 year after ACDF. Methods. Eighty-nine patients with a minimum 2-year follow-up were included. ACDF surgery using allograft and plating was performed: single-level in 51 patients, two-level in 26 patients, and three-level in 12 patients. Presence of pseudarthrosis was evaluated 1 year postoperatively and then the nonunion segments were re-evaluated 2 years postoperatively. Demographic data were assessed to identify the risk factors associated with pseudarthrosis. A visual analogue scale for neck/arm pain and the Neck Disability Index were analyzed preoperatively and at 1 and 2 years postoperatively. Results. Pseudarthrosis was detected in 29 patients (32.6%) 1 year postoperatively: 15of 51 patients after single-level surgery, 9 of 26 patients after two-level surgery, and 5 of 12 patients after three-level surgery. Only eight patients showed persistent nonunion at 2 years: 3 of 15 patients after single-level surgery, 3 of 9 after two-level surgery, and 2 of 5 after three-level surgery. The remaining 21 patients (72.4%) achieved bony fusion 2 years postoperatively without any intervention. Patients who underwent two-level or three-level ACDF had a significantly higher pseudarthrosis rate than those who underwent single-level ACDF, with odds ratios of 1.844 and 3.147, respectively. The improvements in visual analogue scale for neck pain and Neck Disability Index scores in the persistent nonunion group were significantly lower than those in the final union group at 2 years. Conclusion. Patients with pseudarthrosis detected 1 year postoperatively may be observed without any intervention because approximately 70% of them will eventually fuse by the 2-year point. Early revision could, however, be considered if the pseudarthrosis is associated with considerable neck pain after multilevel ACDF. Level of Evidence: 3

Multilevel posterior foraminotomy with laminoplasty versus laminoplasty alone for cervical spondylotic myelopathy with radiculopathy: a comparative study

BACKGROUND CONTEXT Conventional laminoplasty is useful for expanding a stenotic spinal canal. However, it has limited use for the decompression of accompanying neural foraminal stenosis. As such, an additional posterior foraminotomy could be simultaneously applied, although this procedure carries a risk of segmental kyphosis and instability. PURPOSE The aim of this study was to elucidate the long-term surgical outcomes of additional posterior foraminotomy with laminoplasty (LF) for cervical spondylotic myelopathy (CSM) with radiculopathy. STUDY DESIGN/SETTING A retrospective comparative study was carried out. PATIENT SAMPLE Ninety-eight consecutive patients who underwent laminoplasty for CSM with radiculopathy between January 2006 and December 2012 were screened for eligibility. This study included 66 patients, who were treated with a laminoplasty of two or more levels and followed up for more than 2 years after surgery. OUTCOME MEASURES The Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) scores, JOA recovery rates, and visual analog scale (VAS) were used to evaluate clinical outcomes. The C2-C7 sagittal vertical axis distance, cervical lordosis, range of motion (ROM), and angulation and vertebral slippage at the foraminotomy level were used to measure radiological outcomes using the whole spine anterioposterior or lateral and dynamic lateral radiographs. METHODS Sixty-six patients with CSM with radiculopathy involving two or more levels were consecutively treated with laminoplasty and followed up for more than 2 years after surgery. The first 26 patients underwent laminoplasty alone (LA group), whereas the next 40 patients underwent an additional posterior foraminotomy at stenotic neural foramens with radiating symptoms in addition to laminoplasty (LF group). In the LF group, the foraminotomy with less resection than 50% of facet joint to avoid segmental kyphosis and instability was performed at 78 segments (unilateral-to-bilateral ratio=57:21) and 99 sites. Clinical and radiographic data were assessed preoperatively and at 2-year follow-up and compared between the groups. RESULTS The NDI, JOA scores, JOA recovery rates, and VAS for neck and arm pain were improved significantly in both groups after surgery. The improvement in the VAS for arm pain was significantly greater in the LF group (from 5.55±2.52 to 1.85±2.39) than the LA group (from 5.48±2.42 to 3.40±2.68) (p<.001). Although cervical lordosis and ROM decreased postoperatively in both groups, there were no significant differences in the degree of reduction between the LF and LA groups. Although the postoperative focal angulation and slippage were slightly increased in the LF group, this was not to a significant degree. Furthermore, segmental kyphosis and instability were not observed in the LF group, regardless of whether the patient underwent a unilateral or bilateral foraminotomy. CONCLUSIONS Additional posterior foraminotomy with laminoplasty is likely to improve arm pain more significantly than laminoplasty alone by decompressing nerve roots. Also, performing posterior foraminotomy via multiple levels or bilaterally did not significantly affect segmental malalignment and instability. Therefore, when a laminoplasty is performed for CSM with radiculopathy, an additional posterior foraminotomy could be an efficient and safe treatment that improves both myelopathy symptoms and radicular arm pain.

Comparison of Revision Rates Due to Aseptic Loosening between High-Flex and Conventional Knee Prostheses

Purpose The purpose was to evaluate and compare the revision rate due to aseptic loosening between a high-flex prosthesis and a conventional prosthesis. Materials and Methods Two thousand seventy-eight knees (1,377 patients) with at least 2 years of follow-up after total knee arthroplasty were reviewed. Two types of implants were selected (LPS-Flex and LPS, Zimmer) to compare revision and survival rates and sites of loosened prosthesis component. Results The revision rate of the LPS-Flex (4.9%) was significantly higher than that of the conventional prosthesis (0.6%) (p<0.001). The 5-, 10-, and 15-year survival rates were 98.9%, 96.2% and 92.0%, respectively, for the LPS-Flex and 99.8%, 98.5% and 93.5%, respectively, for the LPS. The survival rate of the high-flex prosthesis was significantly lower than that of the conventional prosthesis, especially in the mid-term period (range, 5 to 10 years; p=0.002). The loosening rate of the femoral component was significantly higher in the LPS-Flex prosthesis (p=0.001). Conclusions The LPS-Flex had a higher revision rate due to aseptic loosening than the LPS prosthesis in the large population series with a long follow-up. The LPS-Flex should be used carefully considering the risk of femoral component aseptic loosening in the mid-term (range, 5 to 10 years) follow-up period after initial operation.

Can C3 Laminectomy Reduce Interlaminar Bony Fusion and Preserve the Range of Motion After Cervical Laminoplasty

Study Design. Retrospective comparative study. Objective. To investigate whether the resection of C3 lamina during cervical laminoplasty can prevent C2-C4 interlaminar bony fusion and preserve the range of motion (ROM) postoperatively. Summary of Background Data. Interlaminar bony fusion is a common complication after cervical laminoplasty, especially in the C2-C4. Laminectomy, rather than laminoplasty, of C3 has been recently introduced. Its advantages include minimizing muscle detachment at C2 and reducing postoperative neck pain. Methods. A total of 59 patients with cervical spondylotic myelopathy that involved three or more levels, including C3, were consecutively treated with laminoplasty and followed up for more than 3 years after surgery. The first 45 patients underwent open-door laminoplasty at C3 (Lp group) and the subsequent 14 patients underwent laminectomy at C3 rather than laminoplasty (Ln group). The Lp group was further divided into two subgroups based on the development of interlaminar bony fusion at C2-C3 and/or C3-C4: Lp-NF (nonfusion) and Lp-F (fusion) groups. Clinical outcomes and radiographic parameters were assessed pre- and postoperatively. Results. Nineteen out of 45 patients who underwent laminoplasty demonstrated fusion at 3-year follow up. Fusion developed more commonly in those patients who had a smaller preoperative ROM at C2-C4 segments (Lp-F 14.3° ± 6.9° vs. Lp-NF 21.4° ± 5.3°, P = 0.013). The neck disability index (range, 13.4 ± 7.3 to 6.3 ± 5.2, P < 0.001), visual analog scale for neck pain (range, 2.5 ± 1.7 to 0.9 ± 1.3, P = 0.027), Japanese Orthopedic Association (JOA) score (range, 14.3 ± 1.9 to 16.0 ± 2.4, P < 0.001), and JOA recovery rate (63.4 ± 19.8%) in the Ln group improved postoperatively; however, there was no significant difference in the improvement of these clinical outcomes among all three groups. Postoperative cervical ROM was significantly reduced in all groups; however, the extent of reduction was significantly smaller in the Ln group (10.5°; range, 44.2° ± 9.1° to 33.7 ± 6.0°) than in the Lp-NF (15.1°; range, 45.4° ± 8.5° to 30.3° ± 7.4°) or Lp-F (18.2°; range, 39.6° ± 9.3° to 21.4° ± 10.3°) groups (P < 0.05). Conclusion. C3 laminectomy with laminoplasty can prevent interlaminar bony fusion at C2-C4 and, ultimately, result in better preservation of cervical ROM than C3 laminoplasty. Furthermore, it yields similar clinical outcomes when compared with C3 laminoplasty. Level of Evidence: 3

Agreement on the Level Selection in Laminoplasty among Experienced Surgeons: A Survey-Based Study

Study Design Survey based study. Purpose To assess the degree of agreement in level selection of laminoplasty (LP) for the selected cervical myeloradiculopathy cases between experienced spine surgeons. Overview of Literature Although, cervical LP is a widely used surgical technique for multi-level spinal cord compression, until now there is no consensus about how many segments or which segments should be opened to achieve a satisfactory decompression. Methods Thorough clinical and radiographic data (plain X-ray, computed tomography, and magnetic resonance imaging) of 30 patients who had cervical myelopathy were prepared. The data were provided to three independent spine surgeons with over 10 years experience in operation of their own practices. They were questioned about the most preferable surgical method and suitable decompression levels. The second survey was carried out after 6 months with the same cases. If the level difference between respondents was a half level or below, agreement was considered acceptable. The intraobserver and interobserver agreements in level selection were assessed by kappa statistics. Results Three respondents selected LP as an option for 6, 8, and 22 cases in the first survey and 10, 21, and 24 cases in the second survey. The reasons for selection of LP were levels of ossification of the posterior longitudinal ligament (p=0.004), segmental kyphotic deformity (p=0.036) and mean compression score (p=0.041). Intraobserver agreement showed variable results. Interobserver agreement was poor to fair by perfect matching (kappa=0.111–0.304) and fair to moderate by acceptable matching (kappa=0.308–0.625). Conclusions The degree of agreement for level selection of LP was not high even though experienced surgeons would choose the opening segments on the basis of same criteria. These results suggest that more specific guidelines in determination of levels for LP should be required to decrease unnecessary wide decompression according to individual variance.

Is one-stage Posterior Corpectomy More Favorable Compared to Decompression with Fusion to Control Thoracic Cord Compression by Metastasis?

Study design: A retrospective comparative study Objective: To compare 1-stage posterior corpectomy to decompression with fusion for the control of thoracic cord compression due to a metastatic tumor. Summary of Background Data: Thoracic cord compression by a metastatic tumor can cause back pain, paralysis, and urinary/bowel dysfunction and is generally treated by palliative decompressive surgery. However, no studies have assessed the advantages of 1-stage posterior corpectomy compared with decompression with fusion. Methods: We studied 18 patients who underwent surgery for thoracic cord compression due to metastatic tumors between September 2009 and August 2013. Neurological examination was performed preoperatively and postoperatively. Data on operative time, blood loss during surgery, postoperative complications, and survival time were retrospectively retrieved from electronic medical records. Patients were divided into 2 groups based on treatment: decompression and corpectomy (corpectomy group, n=8) and decompression with fusion (decompression-fusion group, n=10). Data were statistically compared between the 2 groups. Results: The mean age of the patients was 61±12 years. Motor weakness and urinary/bowel dysfunction were observed in 15 and 9 cases, respectively. Five patients, who could walk before surgery, could walk at 1 month following surgery. However, only 3 of the 13 patients who could not walk before surgery regained the ability to walk. No difference was found in the degree of muscle strength recovery between the 2 groups. However, the corpectomy group showed higher blood loss (2200 vs. 710 mL, P=0.037) and longer operative time (281 vs. 217 min, P=0.029) than the decompression-fusion group. Conclusions: There is no significant advantage of 1-stage posterior corpectomy over decompression with fusion. Furthermore, more blood loss and longer operative time may increase the risk of postoperative complications following corpectomy. For this reason, 1-stage posterior corpectomy to control thoracic metastasis should be considered with caution.STUDY DESIGN Retrospective comparative studyOBJECTIVE:: To compare one-stage posterior corpectomy to decompression with fusion for the control of thoracic cord compression due to a metastatic tumor. SUMMARY OF BACKGROUND DATA Thoracic cord compression by a metastatic tumor can cause back pain, paralysis, and urinary/bowel dysfunction and is generally treated by palliative decompressive surgery. However, no studies have assessed the advantages of one-stage posterior corpectomy compared to decompression with fusion. METHODS We studied 18 patients who underwent surgery for thoracic cord compression due to metastatic tumors between September 2009 and August 2013. Neurologic examination was done pre- and postoperatively. Data on operative time, blood loss during surgery, postoperative complications, and survival time were retrospectively retrieved from electronic medical records. Patients were divided into two groups based on treatment: decompression and corpectomy (corpectomy group, n=8) or decompression with fusion (decompression-fusion group, n=10). Data were statistically compared between the two groups. RESULTS The mean age of the patients was 61±12 years. Motor weakness and urinary/bowel dysfunction were observed in 15 and 9 cases, respectively. Five patients, who could walk before surgery, could walk at 1 month following surgery. However, only three of the 13 patients who could not walk before surgery regained the ability to walk. No difference was found in the degree of muscle strength recovery between the two groups. However, the corpectomy group showed higher blood loss (2200 mL vs. 710 cc, P=0.037) and longer operative time (281 min vs. 217 min, P=0.029) than the decompression-fusion group. CONCLUSIONS There is no significant advantage of one-stage posterior corpectomy over decompression with fusion. Furthermore, more blood loss and longer operative time may increase the risk of postoperative complications following corpectomy. For this reason, one-stage posterior corpectomy to control thoracic metastasis should be considered with caution.