Clinical Analysis of Acute Radiculopathy after Osteoporotic Lumbar Compression Fracture

Objective

The purpose of this study was to analyze the relationship between fracture pattern and the development of acute radiculopathy after osteoporotic lumbar compression fracture.

Methods

This study included 59 patients who underwent bone cement augmentation for osteoporotic compression fracture below the L2 level, which can lead to radiculopathic radiating pain. The patients were divided into two groups according to the presence of radiculopathy (group A : back pain only; group B : back pain with newly developed radiating pain). We categorized compression fractures into three types by the position of the fracture line. The incidence of newly developed radiculopathy was examined retrospectively for each compression fracture type.

Results

The overall incidence of newly developed leg pain (group B) was 25%, and the frequency increased with descending spinal levels (L2 : 0%, L3 : 22%, L4 : 43%, and L5 : 63%). The back pain-only group (group A) had mostly superior-type fractures. On the other hand, the back pain with radiculopathy group (group B) had mostly inferior-type fractures. Most patients in group B showed significant relief of leg pain as well as back pain after bone cement augmentation.

Conclusion

The incidence of a newly developed, radiating pain after osteoporotic compression fractures increased gradually from the L3 to L5 levels. Most of these fractures were of the inferior type, and the bone cement augmentation procedures seemed to be sufficient for relief of both back and radiating pain.     

Balloon Kyphoplasty through Extrapedicular Approach in the Treatment of Middle Thoracic Osteoporotic Compression Fracture : T5-T8 Level

Objective

Kyphoplasty performed in the middle thoracic spine presents technical challenges that differ from those in the lower thoracic or lumbar region due to small pedicle size and angular severity for thoracic kyphosis. The purpose of this study was to evaluate the efficacy of balloon kyphoplasty through extrapedicular approach for the treatment of intractable osteoporotic compression fractures in the middle thoracic spine.

Methods

The patients who were performed with one level balloon kyphoplasty through extrapedicular approach due to painful osteoporotic compression fractures at T5-T8 from June 2003 to July 2005 were retrospectively analyzed. Imaging and clinical features were analyzed including involved vertebrae level, vertebral height, injected cement volume, clinical outcome and complications.

Results

Eighteen female patients (age ranged from 60 to 77 years old) were included in this study. The average amount of the implanted cement was 4.2±1.5 cc. The mean cobb angle and compression rate were improved from 12.1±6.5° to 8.5±7.2° and from 30% to 15%, respectively. The mean pain score (visual analogue scale) prior to kyphoplasty was 7.9 and it decreased to 3.0 after the procedure. Cement leakage to the adjacent disc (2 cases) and paravertebral soft tissues (1 case) were seen but there were no major complications such as pneumothorax, segmental artery injury, pulmonary embolism, or epidural leakage.

Conclusion

Balloon kyphoplasty through extrapedicular approach is considered as a safe and effective in treating the middle thoracic regions with low complication rate.     

The Proper Volume and Distribution of Cement Augmentation on Percutaneous Vertebroplasty

Objective

The purpose of this study was to determine the optimal volume of injected cement and its distribution when used to treat vertebral compression fractures, and to identify factors related to subsequent vertebral fractures.

Methods

A retrospective analysis of newly developing vertebral fractures after percutaneous vertebroplasty was done. The inclusion criteria were that the fracture was a single first onset fracture with exclusion of pathologic fractures. Forty-three patients were included in the study with a minimum follow up period of six months. Patients were dichotomized for the analysis by volume of cement, initial vertebral height loss, bone marrow density, and endplate-to-endplate cement augmentation.

Results

None of the four study variables was found to be significantly associated with the occurrence of a subsequent vertebral compression fracture. In particular, and injected cement volume of more or less that 3.5 cc was not associated with occurrence (p = 0.2523). No relation was observed between initial vertebral height loss and bone marrow density (p = 0.1652, 0.2064). Furthermore, endplate-to-endplate cement augmentation was also not found to be significantly associated with a subsequent fracture (p = 0.2860) by Fisher''s exact test.

Conclusion

Neither volume of cement, initial vertebral height loss, bone marrow density, or endplate-to-endplate cement augmentation was found to be significantly related to the occurrence of a subsequent vertebral compression fracture. Our findings suggest that as much cement as possible without causing leakage should be used.     

Bone Cement Augmentation of Short Segment Fixation for Unstable Burst Fracture in Severe Osteoporosis

Objective

The purpose of this study was to determine the efficacy of short segment fixation following postural reduction for the re-expansion and stabilization of unstable burst fractures in patients with osteoporosis.

Methods

Twenty patients underwent short segment fixation following postural reduction using a soft roll at the involved vertebra in cases of severely collapsed vertebrae of more than half their original height. All patients had unstable burst fracture with canal compromise, but their motor power was intact. The surgical procedure included postural reduction for 2 days and bone cement-augmented pedicle screw fixations at one level above, one level below and the fractured level itself. Imaging and clinical findings, including the level of the vertebra involved, vertebral height restoration, injected cement volume, local kyphosis, clinical outcome and complications were analyzed.

Results

The mean follow-up period was 15 months. The mean pain score (visual analogue scale) prior to surgery was 8.1, which decreased to 2.8 at 7 days after surgery. The kyphotic angle improved significantly from 21.6±5.8° before surgery to 5.2±3.7° after surgery. The fraction of the height of the vertebra increased from 35% and 40% to 70% in the anterior and middle portion. There were no signs of hardware pull-out, cement leakage into the spinal canal or aggravation of kyphotic deformities.

Conclusion

In the management of unstable burst fracture in patients with severe osteoporosis, short segment pedicle screw fixation with bone cement augmentation following postural reduction can be used to reduce the total levels of pedicle screw fixation and to correct kyphotic deformities.     

Segmental Deformity Correction after Balloon Kyphoplasty in the Osteoporotic Vertebral Compression Fracture

Objective

Balloon kyphoplasty can effectively relieve the symptomatic pain and correct the segmental deformity of osteoporotic vertebral compression fractures. While many articles have reported on the effectiveness of the procedure, there has not been any research on the factors affecting the deformity correction. Here, we evaluated both the relationship between postoperative pain relief and restoration of the vertebral height, and segmental kyphosis, as well as the various factors affecting segmental deformity correction after balloon kyphoplasty.

Methods

Between January 2004 and December 2006, 137 patients (158 vertebral levels) underwent balloon kyphoplasty. We analyzed various factors such as the age and sex of the patient, preoperative compression ratio, kyphotic angle of compressed segment, injected PMMA volume, configuration of compression, preoperative bone mineral density (BMD) score, time interval between onset of symptom and the procedure, visual analogue scale (VAS) score for pain rating and surgery-related complications.

Results

The mean postoperative VAS score improvement was 4.93±0.17. The mean postoperative height restoration rate was 17.8±1.57% and the kyphotic angle reduction was 1.94±0.38°. However, there were no significant statistical correlations among VAS score improvement, height restoration rate, and kyphotic angle reduction. Among the various factors, the configuration of the compressed vertebral body (p=0.002) was related to the height restoration rate and the direction of the compression (p=0.006) was related with the kyphotic angle reduction. The preoperative compression ratio (p=0.023, p=0.006) and injected PMMA volume (p<0.001, p=0.035) affected both the height restoration and kyphotic angle reduction. Only the preoperative compression ratio was found to be as an independent affecting factor (95% CI : 1.064-5.068).

Conclusion

The two major benefits of balloon kyphoplasty are immediate pain relief and local deformity correction, but segmental deformity correction achieved by balloon kyphoplasty does not result in additional pain relief. Among the factors that were shown to affect the segmental deformity correction, configuration of the compressed vertebral body, direction of the most compressed area, and preoperative compression ratio were not modifiable. However, careful preoperative consideration about the modifiable factor, the PMMA volume to inject, may contribute to the dynamic correction of the segmental deformity.     

Unilateral Extrapedicular Vertebroplasty and Kyphoplasty in Lumbar Compression Fractures : Technique, Anatomy and Preliminary Results

Objective

A single balloon extrapedicular kyphoplasty has been introduced as one of the unilateral approaches for thoracic compression fractures; however, the unilateral extrapedicular technique in the lumbar area needs a further understanding of structures in the lumbar area. The purpose of the present study is to describe methods and pitfalls of this procedure based on the anatomy of the lumbar area and to analyze clinical outcome and complications.

Methods

Anatomical evaluation was performed with 2 human cadavers. A retrospective review of unilateral extrapedicular approaches yielded 74 vertebral levels in 55 patients that were treated with unilateral extrapedicular vertebroplasty and kyphoplasty. Radiographic assessment included the restoration rate of vertebral height and correction of kyphosis.

Results

Anatomical evaluation indicates that the safe needle entry zone of bone for the extrapedicular approach was located in the supero-lateral aspect of the junction between the pedicle and vertebral body. The unilateral extrapedicular procedure achieved adequate pain relief with a mean decreases in pain severity of 7.25±1.5 and 2.0±1.4, respectively. Complications were 1 retroperitoneal hematoma, 6 unilateral fillings and 3 epidural leak of the polymethylmethacrylate.

Conclusion

The method of a unilateral extrapedicular approach in kyphoplasty and vertebroplasty in the lumbar area might be similar to that in thoracic approach using a route via the extrapedicular space. However, different anatomical characteristics of the lumbar area should be considered.     

Bone Cement-Augmented Short Segment Fixation with Percutaneous Screws for Thoracolumbar Burst Fractures Accompanied by Severe Osteoporosis

Objective

The purpose of this study was to determine the efficacy of bone cement-augmented short segment fixation using percutaneous screws for thoracolumbar burst fractures in a background of severe osteoporosis.

Methods

Sixteen patients with a single-level thoracolumbar burst fracture (T11-L2) accompanying severe osteoporosis treated from January 2008 to November 2009 were prospectively analyzed. Surgical procedures included postural reduction for 3 days and bone cement augmented percutaneous screw fixation at the fracture level and at adjacent levels without bone fusion. Due to the possibility of implant failure, patients underwent implant removal 12 months after screw fixation. Imaging and clinical findings, including involved vertebral levels, local kyphosis, canal encroachment, and complications were analyzed.

Results

Prior to surgery, mean pain score (visual analogue scale) was 8.2 and this decreased to a mean of 2.2 at 12 months after screw fixation. None of the patients complained of pain worsening during the 6 months following implant removal. The percentage of canal compromise at the fractured level improved from a mean of 41.0% to 18.4% at 12 months after surgery. Mean kyphotic angle was improved significantly from 19.8° before surgery to 7.8 at 12 months after screw fixation. Canal compromise and kyphotic angle improvements were maintained at 6 months after implant removal. No significant neurological deterioration or complications occurred after screw removal in any patient.

Conclusion

Bone cement augmented short segment fixation using a percutaneous system can be an alternative to the traditional open technique for the management of selected thoracolumbar burst fractures accompanied by severe osteoporosis.     

Clinical Outcomes after Percutaneous Vertebroplasty for Pathologic Compression Fractures in Osteolytic Metastatic Spinal Disease

Objective

Percutaneous vertebroplasty (VP) can provide immediate stabilization in pathologic fractures of spinal tumors. However, long term follow-up data in cases of pathologic fractures are lacking. The authors report follow-up results of VP in 185 pathologic fractures of 102 spinal tumor patients.

Methods

Percutaneous VP was performed at 185 vertebral bodies of 102 patients from 2001 to 2007. Retrospective analysis was done with medical records and radiological data. The change of visual analogue score (VAS), vertebral body (VB) height and kyphotic angle were measured preoperatively and on postoperative one day and at 3, 6, and 12 months.

Results

The patients were composed of metastatic spine tumors (81%) and multiple myeloma (19%). Involved spinal segments were between T6 and L5. Mean follow-up period was 12.2 months. VAS for back pain was 8.24 preoperatively, 3.59 (postoperative one day), 4.08 (three months) and 5.22 (one year). VB compression ratio changed from 21.33% preoperatively to 13.82% (postoperative one day), 14.36% (three month), and 16.04% (one year). Kyphotic angle changed from 15.35° preoperatively to 12.03° (postoperative one day), 13.64° (three month), and 15.61° (one year).

Conclusion

Immediate pain relief was definite after VP in pathologic compression fracture of osteolytic spinal disease. Although VAS was slightly increased on one year follow-up, VP effect was maintained without significant change. These results indicate that VP could be a safe and effective procedure as a palliative treatment of the spinal tumor patients.     

Implant Removal after Percutaneous Short Segment Fixation for Thoracolumbar Burst Fracture : Does It Preserve Motion?

Objective

The purpose of this study was to evaluate the efficacy of implant removal of percutaneous short segment fixation after vertebral fracture consolidation in terms of motion preservation.

Methods

Between May 2007 and January 2011, 44 patients underwent percutaneous short segment screw fixation due to a thoracolumbar burst fracture. Sixteen of these patients, who underwent implant removal 12 months after screw fixation, were enrolled in this study. Motor power was intact in all patients, despite significant vertebral height loss and canal compromise. The patients were divided into two groups by degree of osteoporosis : Group A (n=8), the non-osteoporotic group, and Group B (n=8), the osteoporotic group. Imaging and clinical findings including vertebral height loss, kyphotic angle, range of motion (ROM), and complications were analyzed.

Results

Significant pain relief was achieved in both groups at final follow-up versus preoperative values. In terms of vertebral height loss, both groups showed significant improvement at 12 months after screw fixation and restored vertebral height was maintained to final follow-up in spite of some correction loss. ROM (measured using Cobb''s method) in flexion and extension in Group A was 10.5° (19.5/9.0°) at last follow-up, and in Group B was 10.2° (18.8/8.6°) at last follow-up. Both groups showed marked improvement in ROM as compared with the screw fixation state, which was considered motionless.

Conclusion

Removal of percutaneous implants after vertebral fracture consolidation can be an effective treatment to preserve motion regardless of osteoporosis for thoracolumbar burst fractures.     

The Analysis of Patterns and Risk Factors of Newly Developed Vertebral Compression Fractures after Percutaneous Vertebroplasty

Objective

The purpose of this study was to investigate the patterns and the risk factors of newly developed vertebral compression fractures (VCFs) after percutaneous vertebroplasty (PVP).

Methods

We performed a retrospective review of the 244 patients treated with PVP from September 2006 to February 2011. Among these patients, we selected 49 patients with newly developed VCFs following PVP as the new VCFs group, and the remaining 195 patients as the no VCFs group. The new VCFs group was further divided into 2 groups : an adjacent fractures group and a nonadjacent fractures group. The following data were collected from the groups : age, gender, body weight/height, body mass index (BMI), bone mineral density (BMD) score of the spine and femur, level of initial fracture, restoration rate of anterior/middle vertebral height, and intradiscal cement leakage, volume of polymethylmethacrylate (PMMA).

Results

Age, gender, mean body height/weight, mean BMI and volume of PMMA of each of the group are not statistically significantly associated with fractures. In comparison between the new VCFs group and the no VCFs group, lower BMD, intradiscal cement leakage and anterior vertebral height restoration were the significant predictive factors of the fracture. In addition, new VCFs occurrence at the adjacent spines was statistically significant, when the initial fracture levels were confined to the thoracolumbar junction, among the subgroups of new VCFs.

Conclusion

Lower spinal BMD, the greater anterior vertebral height restoration rate and intradiscal cement leakage were confirmed as risk factors for newly formed VCFs after PVP.     

The Prognostic Factors Influencing on the Therapeutic Effect of Percutaneous Vertebroplasty in Treating Osteoporotic Vertebral Compression Fractures

Objective

This retrospective study of 215 patients with 383 symptomatic osteoporotic vertebral compression fractures (VCFs) treated by percutaneous vertebroplasty (PVP), was performed to evaluate the clinical outcomes, and to analyze the various clinical factors affecting these results.

Methods

The authors assessed the clinical outcome under the criteria such as the pain improvement, activity, requirement of analgesics, and the patient''s satisfaction, and determined the relation to various peri- and intra-operative factors, and postoperative imaging findings.

Results

The outcome was determined as 84.2% in relief of pain, 72.0% in change in activity, 65.7% in analgesics use, and 84.7% of satisfaction rate. More severe focal back pain, high uptake bone scan, and the lower mean T-score were related to the better pain relief following PVP. The longer the duration between fracture and PVP, the less severe focal back pain, low uptake bone scan, and leakage of PMMA into the paravertebral space were related to the less improvement in activity. Female and low uptake bone scan showed a correlation with more analgesic use. The longer the duration between fracture and PVP, low uptake bone scan, and the higher the mean T-score were correlated with the less the patients satisfaction.

Conclusion

Our study suggests that PVP may be more effective in the acute phase of VCFs, more severe focal pain, and far advanced osteoporosis on BMD. Leakage of PMMA into the paravertebral spcae also could be affecting the surgical results.     

The Patterns of Intraosseous Venography before Percutaneous Vertebroplasty for Osteoporotic Compression Fractures

Objective

Bone cement leakage is a well-known potential complication of percutaneous vertebroplasty (PVP) in patients with osteoporotic compression fracture. Even though there has been a controversy in the efficacy of antecedent venography to prevent this complication, many authors have performed intraosseous venography before bone cement injection. The goal of this study was to classify the venous drainage patterns of spine before PVP, and compare their patterns at different vertebral levels.

Methods

The authors retrospectively reviewed 1,042 intraosseous venographic patterns in 321 patients with 574 osteoporotic compression fractures during six-year period in one institution. To classify venogram patterns, we selected simple lateral X-ray of spine taken immediately after injection of the contrast dye. We classified the venography patterns according to contrast leakage pattern and leakage direction as follows; trabecular (TR), trabecular anterior (TA), trabecular posterior (TP), trabecular anterior-posterior (TAP), trabecular lateral (TL), venous anterior(VA), venous posterior (VP), venous anterior-posterior (VAP), soft tissue (ST). Also, we compared venogram patterns according to different spinal levels.

Results

In overall, the most common pattern was TP type accounting for 37.4% (390/1042) of all intraosseous venograms. This is followed by TAP in 21.5%, TR 17.4%, TA 11.6%, TL 5.8%, ST 4.1%, VA 1.2%, VP 0.6%, and VAP 0.4% in descending order of frequency. According to the spinal level, TR and TAP types were most common in thoracic spine (T6-T10), TP type was most common in thoraco-lumbar spine (T11-L2), and TP and TAP types were most common in lumbo-sacral spine (L3-S1). Contrast dye leakage to soft tissue such as psoas muscle or disc were detected in 43 (4.1%) venograms. Direct venous drainage without staining of vertebral body was found in 23 (2.2%) venograms. The 8.3% of thoracic venogram showed direct venous drainage. Thoracic level showed a more tendency of direct venous drainage than other spine levels (p<0.01).

Conclusion

The authors propose a new classification system of intraosseous venography during PVP. The trabecular-posterior (TP) type is most common through all spine, and venous-filling (V) type was most frequent in thoracic spine. Further study would be necessary to elucidate the efficacy of this classification system to prevent bone cement leakage during PVP.     

Effect of Bone Cement Volume and Stiffness on Occurrences of Adjacent Vertebral Fractures after Vertebroplasty

Objective

The purpose of this study is to find the optimal stiffness and volume of bone cement and their biomechanical effects on the adjacent vertebrae to determine a better strategy for conducting vertebroplasty.

Methods

A three-dimensional finite-element model of a functional spinal unit was developed using computed tomography scans of a normal motion segment, comprising the T11, T12 and L1 vertebrae. Volumes of bone cement, with appropriate mechanical properties, were inserted into the trabecular core of the T12 vertebra. Parametric studies were done by varying the volume and stiffness of the bone cement.

Results

When the bone cement filling volume reached 30% of the volume of a vertebral body, the level of stiffness was restored to that of normal bone, and when higher bone cement exceeded 30% of the volume, the result was stiffness in excess of that of normal bone. When the bone cement volume was varied, local stress in the bony structures (cortical shell, trabecular bone and endplate) of each vertebra monotonically increased. Low-modulus bone cement has the effect of reducing strain in the augmented body, but only in cases of relatively high volumes of bone cement (>50%). Furthermore, varying the stiffness of bone cement has a negligible effect on the stress distribution of vertebral bodies.

Conclusion

The volume of cement was considered to be the most important determinant in endplate fracture. Changing the stiffness of bone cement has a negligible effect on the stress distribution of vertebral bodies.     

Enhancing Box Sign : Enhancement Pattern of Acute Osteoprotic Compression Fracture

Objective

Although gadolinium enhancement of compression fractures is well known, the enhancement pattern of the acute stage of a fracture is not completely understood. Here, we investigated the enhancement pattern of acute vertebral compression fractures (VCFs).

Methods

We conducted a retrospective study of patients with acute osteoporotic VCFs admitted to hospital between January 2004 and December 2005. The demographic details, stage of the fracture, management data, and results were analyzed. There were nine men and 22 women, and the mean age was 71 years (range, 53-92 years). According to the onset of pain, patients were divided into the following four groups : Group I (less than 3 days), Group II (4-7 days), Group III (8-14 days), and Group IV (14-30 days).

Results

All patients had central low-signal intensity of the nonenhancing part of vertebral bodies on T1 images. Enhancing box sign (EBS) was seen 7 days of VCF development. After 7 days of onset (Groups III and IV), patch or Kummell''s enhancements occurred. EBS has been statistically correlated with stage of compression fracture (Pearson''s correlation = -0.774). However, EBS had no statistically significant correlation with prognosis in our study (Pearson''s correlation = 0.059).

Conclusion

EBS represents a characteristic sign 7 days of VCF development.     

Polymethylmethacrylate-Augmented Screw Fixation for Stabilization of the Osteoporotic Spine : A Three-Year Follow-Up of 37 Patients

Objective

The purpose of this study was to determine the efficacy, radiological findings, clinical outcomes and complications in patients with lumbar stenosis and osteoporosis after the use of polymethylmethacrylate (PMMA) augmentation of a cannulated pedicle screw.

Methods

Thirty-seven patients with degenerative spinal stenosis and osteoporosis (T-score < -2.5) underwent lumbar fusion using the Dream Technology Pedicle Screw (DTPS™, Dream Spine Total Solutions, Dream STS, Seoul, Korea) between 2005 and 2007. The clinical outcomes were evaluated by using the visual analog scale (VAS) and the Prolo scale. Radiologic findings were documented through computed tomography (CT) and plain films.

Results

Thirty-seven patients were evaluated and included, 2 males and 35 females with an average bone mineral density (BMD) of 0.47g/cm². The average age of the patients was 68.7 (range, 57-88). The preoperative VAS for low back and leg pain (7.87 ± 0.95 and 8.82 ± 0.83) were higher as compared with postoperative VAS (2.30 ± 1.61 and 1.42 ± 0.73) with statistical significance (p = 0.006, p = 0.003). According to the Prolo scale, 11, 22, one and three patients were in excellent, good, fair and poor conditions, respectively. The average amount of the injected cement per one cannulated screw was 1.83 ± 0.11 mL.

Conclusion

The results show favorable outcome both clinically and radiographically for 37 patients who underwent lumbar fusion using DTPS™ and PMMA. Based on the results, the use of this surgical method can be a safe and effective option for the operation on the osteoporotic spine.     

Short Segment Fixation for Thoracolumbar Burst Fracture Accompanying Osteopenia : A Comparative Study

Objective

The purpose of this study was to compare the results of three types of short segment screw fixation for thoracolumbar burst fracture accompanying osteopenia.

Methods

The records of 70 patients who underwent short segment screw fixation for a thoracolumbar burst fracture accompanying osteopenia (-2.5< mean T score by bone mineral densitometry <-1.0) from January 2005 to January 2008 were reviewed. Patients were divided into three groups based on whether or not bone fusion and bone cement augmentation procedure 1) Group I (n=26) : short segment fixation with posterolateral bone fusion; 2) Group II (n=23) : bone cement augmented short segment fixation with posterolateral bone fusion; 3) Group III (n=21) : bone cement augmented, short segment percutaneous screw fixation without bone fusion. Clinical outcomes were assessed using a visual analogue scale and modified MacNab''s criteria. Radiological findings, including kyphotic angle and vertebral height, and procedure-related complications, such as screw loosening or pull-out, were analyzed.

Results

No significant difference in radiographic or clinical outcomes was noted between patients managed using the three different techniques at last follow up. However, Group I showed more correction loss of kyphotic deformities and vertebral height loss at final follow-up, and Group I had higher screw loosening and implant failure rates than Group II or III.

Conclusion

Bone cement augmented procedure can be an efficient and safe surgical techniques in terms of achieving better outcomes with minimal complications for thoracolumbar burst fracture accompanying osteopenia.     

A Multi-center Clinical Study of Posterior Lumbar Interbody Fusion with the Expandable Stand-alone Cage (Tyche? Cage) for Degenerative Lumbar Spinal Disorders

Objective

This multi-center clinical study was designed to determine the long-term results of patients who received a one-level posterior lumbar interbody fusion with expandable cage (Tyche® cage) for degenerative spinal diseases during the same period in each hospital.

Methods

Fifty-seven patients with low back pain who had a one-level posterior lumbar interbody fusion using a newly designed expandable cage were enrolled in this study at five centers from June 2003 to December 2004 and followed up for 24 months. Pain improvement was checked with a Visual Analogue Scale (VAS) and their disability was evaluated with the Oswestry Disability Index. Radiographs were obtained before and after surgery. At the final follow-up, dynamic stability, quality of bone fusion, interveretebral disc height, and lumbar lordosis were assessed. In some cases, a lumbar computed tomography scan was also obtained.

Results

The mean VAS score of back pain was improved from 6.44 points preoperatively to 0.44 at the final visit and the score of sciatica was reduced from 4.84 to 0.26. Also, the Oswestry Disability Index was improved from 32.62 points preoperatively to 18.25 at the final visit. The fusion rate was 92.5%. Intervertebral disc height, recorded as 9.94±2.69 mm before surgery was increased to 12.23±3.31 mm at postoperative 1 month and was stabilized at 11.43±2.23 mm on final visit. The segmental angle of lordosis was changed significantly from 3.54±3.70° before surgery to 6.37±3.97° by 24 months postoperative, and total lumbar lordosis was 20.37±11.30° preoperatively and 24.71±11.70° at 24 months postoperative.

Conclusion

There have been no special complications regarding the expandable cage during the follow-up period and the results of this study demonstrates a high fusion rate and clinical success.     

Early Vertebroplasty versus Delayed Vertebroplasty for Acute Osteoporotic Compression Fracture : Are the Results of the Two Surgical Strategies the Same?

Objective

In Korea, early vertebroplasty (EVP) or delayed vertebroplasty (DVP, which is performed at least 2 weeks after diagnosis) were performed for the treatment of acute osteoporotic compression fracture (OCF) of the spine. The present study compared the outcomes of two surgical strategies for the treatment of single-level acute OCF in the thoracolumbar junction (T12-L2).

Methods

From 2004 to 2010, 23 patients were allocated to the EVP group (EVPG) and 27 patients to the DVP group (DVPG). Overall mean age was 68.3±7.9 and minimum follow-up period was 1.0 year. Retrospective study of clinical and radiological results was conducted.

Results

No significant differences in baseline characteristics were observed between the two groups. As expected, mean duration from onset to vertebroplasty and mean duration of hospital stay were significantly longer in the DVPG (17.1±2.1 and 17.5±4.2) than in the EVPG (3.8±3.3 and 10.8±5.1, p=0.001). Final clinical outcome including visual analogue scale (VAS), Oswestry Disability Index, and Odom''s criteria did not differ between the two groups. However, immediate improvement of the VAS after vertebroplasty was greater in the EVPG (5.1±1.3) than in the DVPG (4.0±1.0, p=0.002). The proportion of cement leakage was lower in the EVPG (30.4%) than in the DVPG (59.3%, p=0.039). In addition, semiquantitative grade of cement interdigitation was significantly more favorable in the EVPG than in the DVPG (p=0.003). Final vertebral body collapse and segmental kyphosis did not differ significantly between the two groups.

Conclusion

Our findings suggest that EVP achieves a better immediate surgical effect with more favorable cost-effectiveness.     

The Effect of Postural Correction and Subsequent Balloon Inflation in Deformity Correction of Acute Osteoporotic Vertebral Fractures

Objective

To determine deformity correction by postural correction and subsequent balloon inflation in acute vertebral compression fractures (OVCFs) and to examine the effect of bone mineral density on deformity correction.

Methods

A totol of 50 acute OVCFs received balloon kyphoplasty. Lateral radiographs were taken and analyzed at five different time points : 1) preoperative, 2) after placing the patient in prone hyperextended position, 3) after balloon inflation, 4) after deposition of the cement, and 5) postoperative. All fractures were analyzed for height restoration of anterior (Ha), middle (Hm) and posterior (Hp) vertebra as well as Cobb angle and Kyphotic angle. The bone mineral density (BMD) of lumbar spine was measured by dual-energy X-ray absorptiometry. According to the T-score, the patients were divided into two groups which were osteoporosis group and osteopenia group.

Results

Postoperative measurements of Ha, Hm and the Cobb angle demonstrated significant reduction of 4.62 mm, 3.66 mm and 5.34° compared with the preoperative measurements, respectively (each p<0.05). Postural correction significantly increased Ha by 5.51 mm, Hm by 4.35 mm and improved the Cobb angle by 8.32° (each p<0.05). Balloon inflation did not demonstrate a significant improvement of Ha, Hm or the Cobb angle compared with baseline prone hyperextended. Postural correction led to greater improvements of Ha, Hm and Cobb angle in osteoporosis group than osteopenia group (each p<0.05).

Conclusion

In acute OVCFs, the height restoration was mainly attributed to postural correction rather than deformity correction by balloon inflation. BMD affected deformity correction in the process of postural correction.