Chong Suh Lee

Normal patterns of sagittal alignment of the spine in young adults radiological analysis in a Korean population.

Study Design. Radiological analysis and classification of normal patterns of sagittal alignment of the spine. Objective. To classify the patterns of sagittal alignment of the spine in young asymptomatic adults and analyze the differences in the various spinal and pelvic parameters according to these patterns. Summary of Background Data. Previous studies reported that the overall sagittal pattern and balance were more important than the normative values. There are few studies on white populations, classifying the normal patterns of sagittal curvature, and no studies on Asian populations. Methods. Whole spine, standing lateral radiographs of 86 Korean volunteers were taken. The pelvic and spinal parameters (total thoracic kyphosis, horizontal thoracic level, thoracolumbar junctional angle (TLJA), total lumbar lordosis, lower lumbar lordosis, horizontal lumbar level (HLL), lumbar inclination, pelvic tilt, sacral slope (SS), pelvic incidence, spinal balance, spinopelvic balance, and sacropelvic balance) were measured and the correlations of all parameters were analyzed. The volunteers were classified in to three types according to their HLL. The data were analyzed statistically to determine the differences in the parameters and balance between the three types. Results. The HLL showed a significant correlation with the lumbar inclination, junctional level, TLJA, spinal balance, spinopelvic balance, and SS on analyzing the correlation of the parameters. As HLL moved caudally, the TLJA and lumbar inclination increased, whereas the lower lumbar lordosis, pelvic incidence, and SS decreased and spinal balance became more negative. There were no significant differences in total thoracic kyphosis and sacropelvic balance between the three types. Conclusion. The patterns of sagittal alignment could be classified into three types showing that the spinal balance becomes more negative, the lumbar inclination and TLJA increase, the SS and pelvic incidence decrease, and lumbar lordotic curves becomes shorter as the patterns of sagittal curvature move toward type 3. This classification in young adults should be considered individually as a reference for surgeons aiming to restore the lumbar lordosis and sagittal alignment in degenerative lumbar fusion surgery.

A comparative study between thoracoscopic surgery and posterior surgery using all-pedicle-screw constructs in the treatment of adolescent idiopathic scoliosis.

Study Design: A retrospective comparative study. Objective: To present the results of thoracoscopic surgery in the treatment of adolescent idiopathic scoliosis (AIS) and to compare the results of thoracoscopic surgery with those of posterior surgery. Summary of Background Data: Although racoscopic scoliosis correction has attracted attention since the early 2000s, its use has declined gradually, whereas posterior surgery using pedicle screws has become popular. Few studies have compared thoracoscopic surgery with posterior pedicle screw fixation for single thoracic AIS correction. Methods: Sixty-five patients with Lenke type-1 AIS were included and followed up for a minimum of 24 months. Forty-two patients underwent thoracoscopic surgery (thoracoscopic group) and 23 patients underwent posterior surgery (posterior group). Radiographic outcomes, including the correction rate and loss of correction, perioperative morbidities, and complications, were compared. Results: Both groups were similar in terms of the preoperative baseline data. Although the correction rate of major thoracic curve was similar, the posterior group had a tendency to have a greater correction rate (72% vs. 66%). A loss of correction was significantly greater in the thoracoscopic group. The thoracoscopic group had a longer operation time and less intraoperative blood loss, with a lower transfusion rate than the posterior group. There was no difference at the last follow-up in terms of pain score and satisfaction. Five implant failures (12%) occurred in the thoracoscopic group and none in the posterior group. There were 3 patients with significant pulmonary complications necessitating active treatments in the thoracoscopic group. Conclusions: Despite its advantages, thoracoscopic surgery is losing its place in the surgical correction of AIS because of the frequent perioperative pulmonary complications and fixation problems compared with posterior pedicle screw fixation. Nevertheless, it can be utilized in selected cases particularly in cases of patient’s strong demand for minimally invasive surgery.

Characteristics of Back Muscle Strength in Patients with Scheduled for Lumbar Fusion Surgery due to Symptomatic Lumbar Degenerative Diseases

Study Design Cross sectional study. Purpose To evaluate characteristics of back muscle strength in patients scheduled for lumbar fusion surgery. Overview of Literature Little is known regarding muscle strength in patients with symptomatic lumbar degenerative diseases who require fusion surgery. Methods Consecutive 354 patients scheduled for posterior lumbar interbody fusion due to symptomatic degenerative diseases were approached for participation. 316 patients were enrolled. Before surgery, muscle strength was assessed by measuring maximal isometric extension strength at seven angular positions (0°, 12°, 24°, 36°, 48°, 60°, and 72°) and mean isometric strength was calculated. The Oswestry Disability Index (0-100) and visual analogue scale (0-100) for back pain were recorded. Muscle strength was compared according to gender, age (<60, 60-70, and ≥70 years) and scheduled fusion level (short, <3; long, ≥3). Results Isometric strength was significantly decreased compared with previously reported results of healthy individuals, particularly at extension positions (0°-48°, p<0.05). Mean isometric strength was significantly lower in females (p<0.001) and older patients (p<0.05). Differences of isometric strength between short and long level fusion were not significantly different (p>0.05). Isometric strengths showed significant, but weak, inverse correlations with age and Oswestry Disability Index (r<0.4, p<0.05). Conclusions In patients with symptomatic lumbar degenerative diseases, back muscle strength significantly decreased, particularly at lumbar extension positions, and in females and older patients.

Delayed Post-traumatic Vertebral Collapse: MR Categorization and MR-Pathology Correlation

Study Design A retrospective study. Purpose To categorize the MR appearance of ischemic vertebral collapse and to correlate surgical and histologic findings. Overview of Literature X-ray and MRI findings of delayed posttraumatic vertebral collapse shows several patterns. Histopathologic signs of osteonecrosis were present only in minor portion of cases sampled for biopsy of delayed post-traumatic vertebral collapse in the literature. Methods Twenty-one patients (22 vertebral bodies), with surgically and histopathologically proven ischemic vertebral collapse were included. The patients were examined with a 1.5 T MR imager. Spin echo T1- and T2-weighted images were obtained in axial and sagittal planes. Two experienced musculoskeletal radiologists, who reached consensus, evaluated the MR images. Then, MR-pathology correlations were made. Results Four different MR patterns were identified. Fluid patterns, were seen in 14% (3/22) of the affected vertebral bodies, and were characterized by hypo-intense signals on T1-weighted images, and hyper-intense signals, similar to water, on T2-weighted images. Extensive bone necrosis was predominant. Compression pattern, the most common pattern, found in 41% (9/22 vertebral bodies), was characterized by a marked decrease of anterior column height. Bone necrosis, granulation tissue, marrow fibrosis, and reactive new bone formation were found in relatively equal proportion. Granulation pattern, seen in 27% (6/22 vertebral bodies), was characterized by hypo-intense signals on T1-weighted images, and intermediate signals on T2-weighted images. Extensive granulation tissue was predominant. Mixed patterns were present in 18% (4/22), of the vertebral bodies. Conclusions Awareness of histopathologic correlation of MR patterns in patients with delayed post-traumatic vertebral collapse may facilitate effective interpretation of clinical MR images of the spine.

Lumbar Extensor Muscle Size and Isometric Muscle Strength in Women with Symptomatic Lumbar Degenerative Diseases

Study Design A cross-sectional design. Purpose To determine the characteristics of lumbar extensor muscle (LEM) size and isometric muscle strength and examine their correlations in women with lumbar degenerative diseases (LDDs). Overview of Literature Many studies have evaluated the relationship between muscle size and strength, but the results have been controversial. Methods Seventy-four female patients (mean age, 66 years) who consecutively underwent posterior lumbar interbody fusion (L1–S1) were recruited. The cross-sectional area (CSA) of the back extensor muscles was measured between L1–2 to L5–S1, and the total sum of the CSAs at each disc level was calculated. Back extensor muscle strength was evaluated using a MedX lumbar extension machine. The Oswestry Disability Index (ODI, 0–100) and Visual Analog Scale (VAS, 0–10) of lower back pain were determined. Results The mean CSAs of the LEM at each level (L1/2–L5/S1) and the total sum were 34.3, 36.3, 35.1, 31.4, 21.9, and 156.2 cm2, respectively. The mean isometric strength at each angle (range, 0°–72°) was 32.5, 50.1, 72.0, 88.7, 100.7, 112.2, and 126.2 ft-lb, respectively. The mean ODI and VAS scores were 54.6 and 6.6, and the mean body weight and body mass index (BMI) were 59.9 kg and 24.9 kg/m2, respectively. The CSAs of the upper lumbar level (L1–4) and the total sum of the CSAs were associated with isometric strength, which was negatively correlated with patients’ age and ODI and positively associated with body weight and BMI, mainly at higher lumbar flexion angles (48°–72°). Conclusions In women with LDD, LEM sizes of the upper lumbar levels (L1–4) were larger than those of the lower levels (L4–S1) and were positively associated with muscle strength. The upper lumbar levels in patients with LDDs appear to play a compensatory role when degenerative lesions are present in the lower lumbar levels.

Prevalence of Neuropathic Pain and Patient-Reported Outcomes in Korean Adults with Chronic Low Back Pain Resulting from Neuropathic Low Back Pain

Study Design A noninterventional, multicenter, cross-sectional study. Purpose We investigated the prevalence of neuropathic pain (NP) and patient-reported outcomes (PROs) of the quality of life (QoL) and functional disability in Korean adults with chronic low back pain (CLBP). Overview of Literature Among patients with CLBP, 20%–55% had NP. Methods Patients older than 20 years with CLBP lasting for longer than three months, with a visual analog scale (VAS) pain score higher than four, and with pain medications being used for at least four weeks before enrollment were recruited from 27 general hospitals between December 2014 and May 2015. Medical chart reviews were performed to collect demographic/clinical features and diagnosis of NP (douleur neuropathique 4, DN4). The QoL (EuroQoL 5-dimension, EQ-5D; EQ-VAS) and functional disability (Quebec Back Pain Disability Scale, QBPDS) were determined through patient surveys. Multiple linear regression analyses were performed to compare PROs between the NP (DN4≥4) and non-NP (DN4<4) groups. Results A total of 1,200 patients (females: 65.7%; mean age: 63.4±13.0 years) were enrolled. The mean scores of EQ-5D, EQ-VAS, and QBPDS were 0.5±0.3, 55.7±19.4, and 40.4±21.1, respectively. Among all patients, 492 (41.0%; 95% confidence interval, 38.2%–43.8%) suffered from NP. The prevalence of NP was higher in male patients (46.8%; p<0.01), in patients who had pain based on radiological and neurological findings (59.0%; p<0.01), and in patients who had severe pain (49.0%; p<0.01). There were significant mean differences in EQ-5D (NP group vs. non-NP group: 0.4±0.3 vs. 0.5±0.3; p<0.01) and QBPDS (NP group vs. non-NP group: 45.8±21.2 vs. 36.3±20.2; p<0.01) scores. In the multiple linear regression, patients with NP showed lower EQ-5D (β=−0.1; p<0.01) and higher QBPDS (β=7.0; p<0.01) scores than those without NP. Conclusions NP was highly prevalent in Korean patients with CLBP. Patients with CLBP having NP had a lower QoL and more severe dysfunction than those without NP. To enhance the QoL and functional status of patients with CLBP, this study highlights the importance of appropriately diagnosing and treating NP.

The Effects of Intersegmental Compression on the 3-D Correction of Idiopathic Scoliosis Using Thoracoscopic Surgery

Study Design Retrospective study. Purpose To investigate whether intersegmental compression can affect the results of threedimensional correction for idiopathic scoliosis. Overview of Literature Intersegmental compression is usually performed to increase the correction rate and enhance kyphosis restoration. However, it is presumed that the risk of decompensation is increased. Methods Twenty-seven patients with idiopathic scoliosis who were corrected thoracoscopically were divided into two groups: a compression group and a non-compression group. Thoracic and lumbar scoliotic Cobb angles were measured pre-operatively, one week postoperatively, and at last follow-up. Changes in thoracic kyphosis and in sagittal and coronal balance were compared. Results The average correction rates for thoracic scoliotic curves were 70.3% and 58.8% in the compression and non-compression groups, respectively (p=0.023), at 1 week postoperatively. However, these changed to 62.6% and 58.1% at the final follow-up visit (p=0.381). Thoracic kyphosis increased by 37.4% in the compression group and 20.9% in the non-compression group at 1 week postoperatively (p=0.435). Finally, thoracic kyphosis increased by 59.9% and 42.6%(p=0.473), respectively, at final follow-up. Axial rotation was corrected by 45.3% and 24.7% in the compression and non-compression groups, respectively (p=0.214). There were no significant differences in postoperative changes in coronal and sagittal balance between the two groups. Conclusions Three-dimensional correction by intersegmental compression tended to produce better results, especially during the early postoperative period. However, at final follow-up, no significant differences were observed between the two groups in terms of three-dimensional correction. Thus, we conclude that intersegmental compression is not always necessary for thoracoscopic scoliosis correction.

Perioperative Complications of Lumbar Total Disc Replacement

Purpose: To investigate the perioperative complications and their effect on the clinical outcomes after a lumbar total disc replacement (TDR). Materials and Methods: Forty-three patients (18 men and 25 women) who had undergone a lumbar TDR from May 2002 and May 2004 were reviewed. Subgroup analysis was performed to determine if age, gender, previous discectomy, multilevel, learning curve of operator, or the difference between preoperative and postoperative disc height were associated with the development of intraoperative or postoperative complications. The patients rated their low back pain on a visual analogue scale and completed an Oswestry disability index (ODI) at the preoperative and postoperative follow-up. Results: There were 4 cases of intraoperative complications (2 major vein injuries and 2 peritoneal rupture) and 8 cases of postoperative complications (6 radicular pains, 1 subsidence of implant, and 1 dissociation of endplate and polyethylene core). There were no significant differences in the incidence of complications according to age, gender, prior surgery, multilevel, learning curve, or disc height difference (p>0.05). In addition, there were no significant differences in the VAS and ODI between the complication and non-complication groups. Conclusion: The authors experienced a relatively high rate of complications (11/43 patients) following TDR and statistical analysis did not reveal any associated risk factors.