Follistatin Mitigates Myofibroblast Differentiation and Collagen Synthesis of Fibroblasts from Scar Tissue around Injured Flexor Tendons

Clinical and Radiological Changes after Microfracture of Knee Chondral Lesions in Middle-Aged Asian Patients

BACKGROUND: Although microfracture is widely accepted as an effective treatment option for knee chondral lesions, little is known about the deterioration of clinical outcomes and radiological progression in middle-aged patients. Therefore, this study was conducted to evaluate the clinical and radiological changes after microfracture of knee chondral lesions in middle-aged Asian patients. METHODS: A total of 71 patients were included in the study. They were between the ages of 40 and 60 years and underwent arthroscopic microfracture for localized full-thickness cartilage defects of the knee from January 2000 to September 2015. The recovery status of chondral lesions was assessed by using the magnetic resonance observation of cartilage repair tissue (MOCART) score in postoperative magnetic resonance imaging (MRI). Clinical and radiological results were reviewed, and survival rate with conversion to arthroplasty or osteotomy as an end point was evaluated. RESULTS: The mean age of the patients at surgery was 51.3 ± 4.7 years (range, 40 to 60 years), and the mean follow-up period was 7.2 ± 2.6 years (range, 1.0 to 17.4 years). The MOCART scores of 32 patients at mean postoperative 2.1 years showed three cases (9%) of full recovery, two cases (7%) of hyperplastic recovery, 23 cases (70%) with more than 50% filling, and four cases (14%) with less than 50% filling. Clinical scores improved significantly at 1 year after surgery (p < 0.05); however, the scores deteriorated over time after postoperative 1 year, and the mean values reached preoperative levels at postoperative 10 years. Significant radiological progression of arthritis (Kellgren-Lawrence grade) was observed at 5 years after surgery. Four patients underwent total knee arthroplasty during follow-up. CONCLUSIONS: Most patients showed more than 50% of defect filling at 2 years after surgery on MRI. Clinical results of microfracture of knee chondral lesion showed the best improvement at postoperative 1 year but gradually worsened thereafter until postoperative 10 years. Radiological progression of arthritis was observed from 5 years after surgery.

Ogilvie's Syndrome after Lumbar Spinal Surgery

STUDY DESIGN: Case report. OBJECTIVES: We report a case of Ogilvie's syndrome following posterior decompression surgery in a spinal stenosis patient who presented with acute abdominal distension, nausea, and vomiting. SUMMARY OF LITERATURE REVIEW: Ogilvie's syndrome is a rare and potentially fatal disease that can easily be mistaken for postoperative ileus, and is also known as acute colonic pseudo-obstruction. Early recognition and diagnosis enable treatment prior to bowel perforation and requisite abdominal surgery. MATERIALS AND METHODS: An 82-year-old woman presented with 6 months of worsening back pain with walking intolerance due to weakness in both legs. She had hypertension, asthma, and Cushing syndrome without bowel or bladder symptoms. Further workup demonstrated the presence of central spinal stenosis on magnetic resonance imaging. The patient underwent an L2-3 laminectomy and posterior decompression. Surgery was uneventful. RESULTS: The patient presented with acute abdominal distension, nausea, and vomiting on postoperative day 1. The patient was initially diagnosed with adynamic ileus and treated conservatively with bowel rest, reduction in narcotic dosage, and a regimen of stool softeners, laxatives, and enemas. Despite this treatment, her clinical course failed to improve, and she demonstrated significant colonic distension radiographically. Intravenous neostigmine was administered as a bolus with a rapid and dramatic response. CONCLUSION: Ogilvie's syndrome should be included in the differential diagnosis of postoperative ileus in patients developing prolonged unexplained abdominal distension and pain after lumbar spinal surgery. Early diagnosis and initiation of conservative management can prevent major morbidity and mortality due to bowel ischemia and perforation.

Ogilvie's Syndrome after Lumbar Spinal Surgery

OBJECTIVES@#We report a case of Ogilvie's syndrome following posterior decompression surgery in a spinal stenosis patient who presented with acute abdominal distension, nausea, and vomiting.SUMMARY OF LITERATURE REVIEW: Ogilvie's syndrome is a rare and potentially fatal disease that can easily be mistaken for postoperative ileus, and is also known as acute colonic pseudo-obstruction. Early recognition and diagnosis enable treatment prior to bowel perforation and requisite abdominal surgery.@*MATERIALS AND METHODS@#An 82-year-old woman presented with 6 months of worsening back pain with walking intolerance due to weakness in both legs. She had hypertension, asthma, and Cushing syndrome without bowel or bladder symptoms. Further workup demonstrated the presence of central spinal stenosis on magnetic resonance imaging. The patient underwent an L2-3 laminectomy and posterior decompression. Surgery was uneventful.@*RESULTS@#The patient presented with acute abdominal distension, nausea, and vomiting on postoperative day 1. The patient was initially diagnosed with adynamic ileus and treated conservatively with bowel rest, reduction in narcotic dosage, and a regimen of stool softeners, laxatives, and enemas. Despite this treatment, her clinical course failed to improve, and she demonstrated significant colonic distension radiographically. Intravenous neostigmine was administered as a bolus with a rapid and dramatic response.@*CONCLUSION@#Ogilvie's syndrome should be included in the differential diagnosis of postoperative ileus in patients developing prolonged unexplained abdominal distension and pain after lumbar spinal surgery. Early diagnosis and initiation of conservative management can prevent major morbidity and mortality due to bowel ischemia and perforation.

Relationship between Lumbar Disc Degeneration and Back Muscle Degeneration

STUDY DESIGN: Retrospective evaluation. OBJECTIVES: To determine the relationship between lumbar disc degeneration and back muscle degeneration. SUMMARY OF LITERATURE REVIEW: In the degenerative cascade of the spine described by Kirkaldy-Willis, degeneration of the disc and of the facet joint co-occur with aging. However, the muscles of the back are not included in this model. Several studies have reported significant correlations between back muscle degeneration and facet joint arthritis. The purpose of our study was to evaluate relationships between lumbar disc degeneration and fatty degeneration of the back muscles. MATERIALS AND METHODS: In this study, 65 patients over the age of 50 years who had undergone lumbar spine MRI in our orthopaedic clinic were recruited. Fatty degeneration of the back muscles was qualitatively graded from I to III by the degree of the fat signal in the muscle layer, including both the multifidus and erector spinae. Lumbar disc degeneration was graded from I to V according to the Pfirrmann grade. Correlations between the back muscle degeneration grade and radiological parameters were analyzed. RESULTS: The degeneration grade of the multifidus correlated positively with age and the grade of disc degeneration. Correlations with other radiologic parameters were not significant. The degeneration grade of the erector spinae correlated positively with age. Other radiologic parameters were not significant. CONCLUSIONS: There was a significant correlation between lumbar disc degeneration and multifidus degeneration. Erector spinae degeneration was correlated with age, but not with lumbar disc degeneration. The degenerative cascade of the spine was accompanied by fatty changes of the multifidus with aging.

Relationship between Lumbar Disc Degeneration and Back Muscle Degeneration

OBJECTIVES@#To determine the relationship between lumbar disc degeneration and back muscle degeneration.SUMMARY OF LITERATURE REVIEW: In the degenerative cascade of the spine described by Kirkaldy-Willis, degeneration of the disc and of the facet joint co-occur with aging. However, the muscles of the back are not included in this model. Several studies have reported significant correlations between back muscle degeneration and facet joint arthritis. The purpose of our study was to evaluate relationships between lumbar disc degeneration and fatty degeneration of the back muscles.@*MATERIALS AND METHODS@#In this study, 65 patients over the age of 50 years who had undergone lumbar spine MRI in our orthopaedic clinic were recruited. Fatty degeneration of the back muscles was qualitatively graded from I to III by the degree of the fat signal in the muscle layer, including both the multifidus and erector spinae. Lumbar disc degeneration was graded from I to V according to the Pfirrmann grade. Correlations between the back muscle degeneration grade and radiological parameters were analyzed.@*RESULTS@#The degeneration grade of the multifidus correlated positively with age and the grade of disc degeneration. Correlations with other radiologic parameters were not significant. The degeneration grade of the erector spinae correlated positively with age. Other radiologic parameters were not significant.@*CONCLUSIONS@#There was a significant correlation between lumbar disc degeneration and multifidus degeneration. Erector spinae degeneration was correlated with age, but not with lumbar disc degeneration. The degenerative cascade of the spine was accompanied by fatty changes of the multifidus with aging.

Medial Meniscal Root Repair Using Curved Guide and Soft Suture Anchor

Medial meniscal root tears have been repaired using various methods. Arthroscopic all-inside repair using a suture anchor is one of the popular methods. However, insertion of the suture anchor into the proper position at the posterior root of the medial meniscus is technically difficult. Some methods have been reported to facilitate suture anchor insertion through a high posteromedial portal, a posterior trans-septal portal, or a medial quadriceptal portal. Nevertheless, many surgeons still have difficulty during anchor insertion. We introduce a technical tip for easy suture anchor insertion using a 25° curved guide and a soft suture anchor through a routine posteromedial portal.

Relationship Between Pelvic Tilt and Lumbar Disc Degeneration

STUDY DESIGN: Retrospective analysis. OBJECTIVES: To determine the relationship between pelvic tilt and lumbar disc degeneration. SUMMARY OF LITERATURE REVIEW: The shape and the spatial orientation of the pelvis determine the organization of the lumbothoracic spine. The purpose of our study was to determine the relationship between pelvic tilt and lumbar disc degeneration. MATERIALS AND METHODS: Sixty patients over 50 years of age who had undergone lumbar spine magnetic resonance imaging were recruited. In individuals between 41 and 60 years of age, the normal pelvic tilt is 14°. Patients were divided into a low pelvic tilt (PT) group (<14°) and a high pelvic tilt (PT) group (≥14°). Lumbar disc degeneration was graded from I to V according to the Pfirrmann grade. We defined grades IV and V as high-grade degeneration and the others as low-grade degeneration. Radiologic parameters and lumbar disc degeneration were compared between these 2 groups. RESULTS: In the low PT group, the average degeneration grade of each lumbar segment was 2.61 in L1-L2, 2.61 in L2-L3, 3.00 in L3-L4, 3.39 in L4-L5, and 3.84 in L5-S1. The corresponding grades in the high PT group were 2.34 in L1-L2, 2.62 in L2-L3, 3.07 in L3-L4, 3.76 in L4-L5, and 3.55 in L5-S1. The grade of degeneration of the high PT group was significantly higher than that of the low PT group for L4-L5 (p=0.031). High-grade degeneration of the L4-L5 segment was significantly more common in the high PT group (odds ratio=4.65; 95% CI, 1.406-15.381; p=0.012). CONCLUSIONS: Patients with high pelvic tilt had a higher grade of lumbar disc degeneration in the L4-L5 segment regardless of age or gender.

Risk Factors for Osteoporotic Vertebral Fracture in Cushing Syndrome

STUDY DESIGN: Retrospective study. OBJECTIVES: The goal of this study was to evaluate the risk factors of osteoporotic vertebral fractures (OVFs) in patients with Cushing syndrome. SUMMARY OF LITERATURE REVIEW: In most reports, vertebral fractures in Cushing syndrome have been found to be related to osteoporosis. However, few studies have analyzed the clinical risk factors for OVFs. MATERIALS AND METHODS: Thirty-two patients with Cushing syndrome who visited the orthopaedic department complaining of back pain were included in this study. Standing lateral X-rays were performed to evaluate the presence of vertebral fractures, and bone mineral density (BMD) was measured. RESULTS: Of the 32 patients with Cushing syndrome with back pain, 8 (25%) were diagnosed with OVFs using morphometric criteria. The average weight and body mass index of the vertebral fracture group (VF group) were significantly higher than the values observed in the non-vertebral fracture group (non-VF group) (p=0.004, p=0.018). Lumbar BMD was significantly lower in the VF group (p=0.006). A risk factor for OVFs in Cushing syndrome was osteoporosis (odds ratio=18.56, 95% confidence interval=1.72-200.21, p=0.016) regardless of gender, obesity, menopause, or urine free cortisol levels. CONCLUSIONS: OVFs in Cushing syndrome have been associated with overweight, and overweight is an indicator of compliance in the treatment of Cushing syndrome. Therefore, weight reduction and the prevention of osteoporosis should be emphasized in patients with Cushing syndrome to prevent OVFs.

The Results of Proximal Femoral Nail for Intertrochanteric Fracture in Hemodialysis Patient / 대한고관절학회지

PURPOSE: Hip fractures in hemodialysis patients are accompanied by high rates of complications and morbidities. Previous studies have mainly reported on nonunion and avascular necrosis of femoral neck fractures in this patient group. In this study the complication and clinical results of hemodialysis patients with intertrochanteric fractures treated with proximal femoral intramedullary nailing have been investigated through comparison with patients with normal kidney function. MATERIALS AND METHODS: Forty-seven patients were included; the hemodialysis group (n=17) and the control group with normal kidney function (n=30). The medical history and clinical findings including preoperative and postoperative blood examinations, radiological examinations and ambulatory status (measured using the Koval score). The rate of complications and morbidities were also investigated and compared. RESULTS: Preoperative hemoglobin/hematocrit was lower but a significant increase in partial thromboplastin time was observed in the hemodialysis group. The amount of bleeding/transfusions were higher and operative time was longer in the hemodialysis group. Upon radiologic examination, there was no significant difference in rate of unstable fracture and nonunion between the two groups. However the postoperative Koval score was significantly worse and the odds ratio of inability to walk after surgery was 13.5 times higher in the hemodialysis group. CONCLUSION: There was no significant difference in radiological results, but the risk of inability to walk after surgery was 13.5 times higher in the hemodialysis group. Hemodialysis patients have more morbidities and are hemodynamically unstable therefore require special attention. Accurate reduction and firm fixation is required and attentive postoperative rehabilitation is needed.

Lumbar Lordosis of Spinal Stenosis Patients during Intraoperative Prone Positioning

BACKGROUND: To evaluate the effect of spondylolisthesis on lumbar lordosis on the OSI (Jackson; Orthopaedic Systems Inc.) frame. Restoration of lumbar lordosis is important for maintaining sagittal balance. Physiologic lumbar lordosis has to be gained by intraoperative prone positioning with a hip extension and posterior instrumentation technique. There are some debates about changing lumbar lordosis on the OSI frame after an intraoperative prone position. We evaluated the effect of spondylolisthesis on lumbar lordosis after an intraoperative prone position. METHODS: Sixty-seven patients, who underwent spinal fusion at the Department of Orthopaedic Surgery of Gwangmyeong Sungae Hospital between May 2007 and February 2012, were included in this study. The study compared lumbar lordosis on preoperative upright, intraoperative prone and postoperative upright lateral X-rays between the simple stenosis (SS) group and spondylolisthesis group. The average age of patients was 67.86 years old. The average preoperative lordosis was 43.5degrees (+/- 14.9degrees), average intraoperative lordosis was 48.8degrees (+/- 13.2degrees), average postoperative lordosis was 46.5degrees (+/- 16.1degrees) and the average change on the frame was 5.3degrees (+/- 10.6degrees). RESULTS: Among all patients, 24 patients were diagnosed with simple spinal stenosis, 43 patients with spondylolisthesis (29 degenerative spondylolisthesis and 14 isthmic spondylolisthesis). Between the SS group and spondylolisthesis group, preoperative lordosis, intraoperative lordosis and postoperative lordosis were significantly larger in the spondylolisthesis group. The ratio of patients with increased lordosis on the OSI frame compared to preoperative lordosis was significantly higher in the spondylolisthesis group. The risk of increased lordosis on frame was significantly higher in the spondylolisthesis group (odds ratio, 3.325; 95% confidence interval, 1.101 to 10.039; p = 0.033). CONCLUSIONS: Intraoperative lumbar lordosis on the OSI frame with a prone position was larger in the SS patients than the spondylolisthesis patients, which also produced a larger postoperative lordosis angle after posterior spinal fusion surgery. An increase in lumbar lordosis on the OSI frame should be considered during posterior spinal fusion surgery, especially in spondylolisthesis patients.

The Use of T1 Sagittal Angle in Predicting Cervical Disc Degeneration

STUDY DESIGN: Retrospective evaluation. PURPOSE: To analyze the effect of T1 slope on degree of degeneration in patients with cervical disc degeneration. OVERVIEW OF LITERATURE: The T1 slope is well known parameter that may be very useful in evaluating sagittal balance. There are no reports on the analysis of the relationship between T1 slope and cervical disc degeneration. We hypothesized that T1 slope has an effect on the degree of cervical degeneration. METHODS: Sixty patients who had cervical spine magnetic resonance imaging (MRI) in our orthopedic clinic were enrolled. Patients were divided into two groups according to T1 slope. Radiologic parameters obtained from radiography and cervical spine MRI were compared between low T1 slope group (25). RESULTS: Among low T1 slope group, average degeneration grade of each cervical segment was 2.65 in C2-3, 2.50 in C3-4, 2.62 in C4-5, 3.23 in C5-6, and 2.81 in C6-7. And that of high T1 group was 2.35 in C2-3, 2.32 in C3-4, 2.59 in C4-5, 2.79 in C5-6, and 2.32 in C6-7. Grade of degeneration of low T1 group was significantly higher, as compared with high T1 group in C5-6 (p=0.028) and C6-7 (p=0.009). Percentage of high grade degeneration of more than grand III was 65.4% in low T1 group and 32.4% in high T1 group (p=0.018). Risk of high grade degeneration of C6-7 was significantly higher in low T1 group (odds ratio, 5.63; 95% confidence interval, 1.665-19.057; p=0.005). CONCLUSIONS: Patients with low T1 slope had higher grade of degeneration regardless of age and gender. Low T1 slope is a potential risk factor of cervical spondylosis especially in the C6-7 cervical segment.

The Short Term Results of Radial Head Arthroplasty with Unipolar Loose Fit Stem

PURPOSE: We report short-term results of radial head prosthesis using a unipolar loose fit stem in ten patients. MATERIALS AND METHODS: Ten patients with Mason type three radial head fracture, who received unipolar radial head arthroplasty from February 2010 to June 2011, were evaluated (mean follow-up: 22 months, range: 18-30 months). Subjects consisted of five men and five women. Range of elbow motion was measured. Mayo elbow performance index (MEPI) score was used for functional evaluation and periodic radiological imaging was performed to evaluate the stability of implant. RESULTS: After an average follow-up of 22 months, elbow stability was maintained in all cases, and the average range of motion of elbow flexion and extension was 6 to 130 degrees. Average range of pronation and supination was 66 and 74 degrees, respectively. MEPI score was evaluated as excellent in seven cases, and good in three cases. On final follow-up, radiological assessment showed implant stability in all cases without evidence of dislocation, subluxation, arthritis, periprosthetic osteolysis or heterotopic ossification. CONCLUSION: Based on our short-term follow-up, radial head arthroplasty with unipolar loose fit stem is a useful method for obtaining satisfactory outcome for unreducible comminuted radial head fractures.

Efficacy of External Fixation and Transfixation Pinning of Distal Radioulnar Joint in Distal Radius Fracture

PURPOSE: The purpose of this study is to evaluate efficacy of percutaneous pinning of distal radioulnar joint in patient with distal radius fracture. METHODS: Thirty-eight patients who underwent percutaneous pinning and external fixation for distal radius fracture were included in this study. Radiologic and clinical outcomes were compared between the patients who underwent percutaneous pinning on the radius only (PD group) and the patients with supplementary pinning on distal radioulnar joint (DRU group) after percutaneous pinning on the radius. External fixation was performed in all patients. RESULTS: Twenty-three patients were PD group and fifteen patients were DRU group. Radial height and radial inclination was significantly higher in DRU group. There was no significant difference in ulnar variance, volar tilt and articular step off between two groups. Among the clinical outcome, there was no significant difference in range of motion between two groups but grip strength was significantly larger in DRU group. CONCLUSION: Percutaneous pinning with K-wires on distal radioulnar joint in distal radius fracture can be a useful procedure for prevention of radial shortening without loss of range of motion of the wrist.

Unstable Intertrochanteric Fracture Treated with ITST: A Comparative Study between Groups with and without Comminution of Greater Trochanter

PURPOSE: To evaluate whether the radiological and clinical results of treatment with intertrochanteric/subtrochanteric (ITST) nail on unstable intertrochanteric fractures are combined with comminution of the greater trochanter or not. MATERIALS AND METHODS: We reviewed the results on 210 cases of unstable intertrochanteric fractures (grouped 88 patients with comminution of greater trochanter [GT] and 122 patients without comminution of GT) treated with ITST nail from January 2007 to October 2011, which was to be followed-up for more than 12 months. RESULTS: The mean union time was 15.2 weeks in the study group (combined with comminution of GT). The mean union time was 14.7 weeks in control group (no comminution of GT). The lag screw sliding was 8.7 mm in the study group and 7.2 mm in the control group. Changes of neck-shaft angle was 4.2degrees in study group and 4.1degrees in control group. Tip-apex distance was 17.4 mm in study group and 16.4 mm in control group. The complications were 4 cases in each study group and control group. The clinical results checked by Skovron recovery scores decreased similarly in both groups, 73.7% in study group and 76.5% in control group. There were no significant differences in both groups according to radiological and clinical results. CONCLUSION: The comminution of great trochanter does not affect on the radiological and clinical results when using the ITST nail of unstable intertrochanteric fractures.

Quality of Life Comparison between Vertebroplasty and Kyphoplasty in Patients with Osteoporotic Vertebral Fractures

STUDY DESIGN: Retrospective evaluation. PURPOSE: To compare quality of life in postmenopausal women with osteoporotic vertebral fractures (OVFs) who underwent vertebroplasty (VP) or kyphoplasty (KP). OVERVIEW OF LITERATURE: Patient with OVFs who do not respond to conservative treatment can be treated with VP or ballon KP for faster pain relief. There are controversies on which procedure is more effective. METHODS: Five hundred twenty-eight postmenopausal women in nationwide hospitals with age of 50 years or older who underwent VP of KP for OVFs were enrolled in this study. Health related quality of life was measured using the European Quality of Life 5 Domains (EQ-5D) and visual analogue scale (VAS). RESULTS: In the VP group, average EQ-5D dimension was 1.95 in mobility, 1.86 in self care, 2.02 in usual activity, 2.19 in pain, 1.69 in anxiety or depression. In the KP group, average EQ-5D dimension was 1.83 in mobility, 1.78 in self care, 1.98 in usual activity, 2.03 in pain, 1.55 in anxiety or depression. Quality of life of KP group was significantly better than that of the VP group in mobility (p=0.016), pain (p=0.001), and anxiety or depression (p=0.008). Average EQ-5D index of the VP and the KP group was 0.353 (+/-0.472) and 0.485 (+/-0.357), respectively. The EQ-5D index of the KP group was significantly (p<0.001) higher than that of the KP group. The difference of VAS between VP and KP group was not statistically significant (p=0.580). CONCLUSIONS: Quality of life in patient with OVFs who underwent KP was significantly better than that of patients who underwent VP.

Failure of Distal Locking Screws in an Intraarticular Distal Radius Fracture Treated with Volar Locking Plate Fixation

Distal radius fracture is one of the most common fractures treated in the orthopedic field. The application of locking plate principle to the distal radius has allowed comminuted distal radius fractures involving the articular surface to be effectively treated by open reduction and internal fixation. The authors experienced a case of failure of distal locking screws in an intraarticular distal radius fracture treated with volar locking plate fixation.

Polyaxial Screws with Thick Rod versus Monoaxial Screws with Thin Rod in Video-Assisted Thoracoscopic Scoliosis Surgery (VATS) / 대한척추외과학회지

STUDY DESIGN: Prospective controlled cohort study OBJECTIVE: To analyze the clinical outcome of video-assisted thoracoscopic surgery (VATS) between two different types of implants. SUMMARY OF LITERATURE REVIEW: The problem of correction loss has been reported with VATS, and different screws and rods have been developed to overcome this problem. Different implants will have varying effects in correctional outcome after VATS. MATERIALS AND METHODS: A total of 39 cases of idiopathic adolescent scoliosis treated with VATS between June 2001 and January 2005 were included in the study (mono-axial screws and a 4.5 mm rod: thin rod group=19 cases; poly-axial reduction screws and a 5.5 mm diameter rod: thick rod group=20 cases). All patients were followed for over 2 years postoperatively. For the comparison of surgical outcomes between the two groups, radiographic measurements were performed in the coronal and sagittal planes. RESULTS: Preoperative scoliosis angle (thin rod group 49.8degrees, thick rod group 47.1degrees), age, BMI, Risser stage, union time, operative time, and blood loss showed no statistical difference between the two groups. Postoperative average correction rate of scoliosis angle was 69% (15.8degrees) in the thin rod group and 70% (14.1degrees) in the thick rod group. However, correction rate after 2 years was 51% (24.5degrees) in the thin rod group and 60% (18.7degrees) in the thick rod group, showing statistically significant difference. There was a tendency toward correction loss in the thin rod group (8.7degrees vs. 4.6degrees p=0.0057). CONCLUSION: Postoperative correction rate was satisfactory in both groups. However, the thin rod group showed substantial correction loss. Therefore, poly-axial screws and thick rods are more suitable in VATS correction of scoliosis.