Computed Tomography Evaluation of Percutaneous Pedicle Screws Inserted during Minimally Invasive Transforaminal Lumbar Interbody Fusion: Long-term Follow-up Results of Screw Violation

Background@#To evaluate the accuracy of percutaneous pedicle screw (PPS) insertion in degenerative lumbar disease treated with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and to analyze risk factors and long-term clinical outcomes of screw violation. @*Methods@#Sixty-two consecutive patients (262 screws) were included. Based on postoperative computed tomography (CT) axial images, a PPS that perforated out of the pedicle was classified into a violation group, while screws surrounded by pedicular cortical bone were classified into a correct group. A logistic regression model was used for risk factor analysis of violation. We also observed the long-term clinical outcomes using the Oswestry disability index and visual analog scale. @*Results@#Of the 262 screws, 14 (5.3%) were considered to be violated (10 medial violations and 4 lateral violations). All violations of S1 and L5 were in the medial direction. In contrast, entire violations of L4 were always lateral and of the 2 violations of L3, one was lateral and the other was medial. There were no cases of superior or inferior violation. The mean pedicle convergence angle (CA) was significantly higher in the violation group (mean ± standard deviation, 27.0° ± 6.2°) than in the correct group (21.7° ± 5.4°).There were no significant differences according to vertebral rotational angle, body mass index, bone mineral density, and surgical timing (learning curve) between the two groups. Logistic regression analyses demonstrated that a high CA was a significant risk factor for pedicle wall violation (p = 0.002). There were no significant differences in clinical or radiographic results between the two groups in 60 patients who were followed up for more than 1 year and in 40 patients who were followed up for more than 5 years. There were 2 patients who required reoperation to replace a screw due to leg pain. @*Conclusions@#With PPS insertion during MI-TLIF, the rate of pedicle violation was 5.3% (14/262). An understanding of the anatomical characteristics of each vertebra and the unique structures of the patient is essential to prevent pedicle violations. Even in the violation group, PPS fixation was found to be a safe and useful procedure with successful long-term radiographic and clinical outcomes.

Management of Osteoporotic Vertebral Fracture: Review Update 2022

A vertebral fracture is the most common type of osteoporotic fracture. Osteoporotic vertebral fractures (OVFs) cause a variety of morbidities and deaths. There are currently few “gold standard treatments” outlined for the management of OVFs in terms of quantity and quality. Conservative treatment is the primary treatment option for OVFs. The treatment of pain includes short-term bed rest, analgesic medication, anti-osteoporotic medications, exercise, and a brace. Numerous reports have been made on studies for vertebral augmentation (VA), including vertebroplasty and kyphoplasty. There is still debate and controversy about the effectiveness of VA in comparison with conservative treatment. Until more robust data are available, current evidence does not support the routine use of VA for OVF. Despite the fact that the majority of OVFs heal without surgery, 15%–35% of patients with an unstable fracture, persistent intractable back pain, or severely collapsed vertebra that causes a neurologic deficit, kyphosis, or chronic pseudarthrosis frequently require surgery. Because no single approach can guarantee the best surgical outcomes, customized surgical techniques are required. Surgeons must stay current on developments in the osteoporotic spine field and be open to new treatment options. Osteoporosis management and prevention are critical to lowering the risk of future OVFs. Clinical studies on bisphosphonate’s effects on fracture healing are lacking. Teriparatide was intermittently administered, which dramatically improved spinal fusion and fracture healing while lowering mortality risk. According to the available literature, there are no standard management methods for OVFs. More multimodal approaches, including conservative and surgical treatment, VA, and medications that treat osteoporosis and promote fracture healing, are required to improve the quality of the majority of guidelines.

Long-Term Clinical and Radiological Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion: 10-Year Follow-up Results

Background@#Many studies have reported that minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) provides satisfactory treatment comparable to other fusion methods. However, in the case of MI-TLIF, there are concerns about the long-term outcome compared to conventional bilateral PLIF due to the small amount of disc removal and the lack of autogenous bone graft. Long-term follow-up studies are still lacking as most of the previous reports have follow-up periods of up to 5 years. @*Methods@#Thirty patients who underwent MI-TLIF were followed up for > 10 years (mean, 11.1 years). Interbody fusion rates were determined using a modified Bridwell grading system.Adjacent segment disease (ASD) was defined as radiological adjacent segment degeneration (R-ASDeg) as seen on plain X-rays; reoperated adjacent segment disease referred to the subsequent need for revision surgery. Clinical outcomes after surgery were assessed based on back and leg pain as well as the Oswestry disability index (ODI). @*Results@#The overall radiological fusion rate, at the 1-, 5-, and 10-year follow-up was 77.1%, 91.4%, and 94.3%, respectively. The incidence of R-ASDeg 1, 5, and 10 years after surgery was 6.7%, 16.7%, and 43.3% at the proximal adjacent segment and 4.8%, 14.3%, and 28.6% at the distal adjacent segment, respectively. R-ASDeg at either the proximal or distal segment was determined in 50.0% of the patients 10 years postoperatively. All clinical parameters improved significantly during follow-up, although the ODI and the visual analog scale (VAS) for leg pain at the 10-year follow-up were significantly worse in the R-ASDeg group than in the other patients (P = 0.009, P = 0.040). @*Conclusion@#MI-TLIF improved both clinical and radiological outcomes, and the improvements were maintained for up to 10 years after surgery. However, R-ASDeg developed in up to 50% of the patients within 10 years, and both leg pain on the VAS and the ODI were worse in patients with R-ASDeg.

Current Concepts of Degenerative Disc Disease -A Significance of Endplate- / 대한정형외과학회잡지

Degenerative disc disease has traditionally been thought of as low back pain caused by changes in the nucleus pulposus and annulus fibrous, in recent studies, however, changes in the upper and lower endplates cause degeneration of the disc, resulting in mechanical pressure, inflammatory reactions and low back pain. Recently, the bone marrow of the vertebral body-endplate-nucleus pulposus and annulus fibrous were considered as a single unit, and the relationship was explained. Once the endplate is damaged, it eventually aggravates the degeneration of the bone marrow, nucleus pulposus, and annulus fibrosus. In this process, the compression force of the annulus fibrosus increases, and an inflammatory reaction occurs due to inflammatory mediators. Hence, the sinuvertebral nerves and the basivertebral nerves are stimulated to cause back pain. If these changes become chronic, degenerative changes such as Modic changes occur in the bone marrow in the vertebrae. Finally, in the case of degenerative intervertebral disc disease, the bone marrow of the vertebral body-endplate-nucleus pulposus and annulus fibrous need to be considered as a single unit. Therefore, when treating patients with chronic low back pain, it is necessary to consider the changes in the nucleus pulposus and annulus fibrosus and a lesion of the endplate.

Current Concepts in the Management of Osteoporotic Vertebral Fractures: A Narrative Review

Vertebral fractures are the most common type of osteoporotic fracture and can increase morbidity and mortality. To date, the guidelines for managing osteoporotic vertebral fractures (OVFs) are limited in quantity and quality, and there is no gold standard treatment for these fractures. Conservative treatment is considered the primary treatment option for OVFs and includes pain relief through shortterm bed rest, analgesics, antiosteoporotic drugs, exercise, and braces. Studies on vertebral augmentation (VA) including vertebroplasty and kyphoplasty have been widely reported, but there is still debate and controversy regarding the effectiveness of VA when compared with conservative treatment, and the routine use of VA for OVF is not supported by current evidence. Although most OVFs heal well, approximately 15%–35% of patients with unstable fractures, chronic intractable back pain, severely collapsed vertebra (leading to neurological deficits and kyphosis), or chronic pseudarthrosis frequently require surgery. Given that there is no single technique for optimizing surgical outcomes in OVFs, tailored surgical techniques are needed. Surgeons need to pay attention to advances in osteoporotic spinal surgery and should be open to novel thoughts and techniques. Prevention and management of osteoporosis is the key element in reducing the risk of subsequent OVFs. Bisphosphonates and teriparatide are mainstay drugs for improving fracture healing in OVF. The effects of bisphosphonates on fracture healing have not been clinically evaluated. The intermittent administration of teriparatide significantly enhanced spinal fusion and fracture healing and reduced mortality risk. Based on the current literature, there is still a lack of standard management strategies for OVF. There is a need for greater efforts through multimodal approaches including conservative treatment, surgery, osteoporosis treatment, and drugs that promote fracture healing to improve the quality of the guidelines.

Current Concepts in the Management of Osteoporotic Vertebral Fractures: A Narrative Review

Vertebral fractures are the most common type of osteoporotic fracture and can increase morbidity and mortality. To date, the guidelines for managing osteoporotic vertebral fractures (OVFs) are limited in quantity and quality, and there is no gold standard treatment for these fractures. Conservative treatment is considered the primary treatment option for OVFs and includes pain relief through shortterm bed rest, analgesics, antiosteoporotic drugs, exercise, and braces. Studies on vertebral augmentation (VA) including vertebroplasty and kyphoplasty have been widely reported, but there is still debate and controversy regarding the effectiveness of VA when compared with conservative treatment, and the routine use of VA for OVF is not supported by current evidence. Although most OVFs heal well, approximately 15%–35% of patients with unstable fractures, chronic intractable back pain, severely collapsed vertebra (leading to neurological deficits and kyphosis), or chronic pseudarthrosis frequently require surgery. Given that there is no single technique for optimizing surgical outcomes in OVFs, tailored surgical techniques are needed. Surgeons need to pay attention to advances in osteoporotic spinal surgery and should be open to novel thoughts and techniques. Prevention and management of osteoporosis is the key element in reducing the risk of subsequent OVFs. Bisphosphonates and teriparatide are mainstay drugs for improving fracture healing in OVF. The effects of bisphosphonates on fracture healing have not been clinically evaluated. The intermittent administration of teriparatide significantly enhanced spinal fusion and fracture healing and reduced mortality risk. Based on the current literature, there is still a lack of standard management strategies for OVF. There is a need for greater efforts through multimodal approaches including conservative treatment, surgery, osteoporosis treatment, and drugs that promote fracture healing to improve the quality of the guidelines.

Comparison of the Efficacy and Safety Profiles of a Mixed ‘PF-72’ and ‘0.75% Ropivacaine HCl’ Versus a ‘0.75% Ropivacaine HCl’ and No Treatment Group: A Randomized, Single-Blind, Single-Institution Pilot Study / 대한척추외과학회지

STUDY DESIGN: Prospective pilot study OBJECTIVES: The efficacy and safety of ‘PF-72’ for management of postoperative acute pain through a mixed ‘PF-72’ and 0.75% ropivacaine hydrochloride solution in patients with posterior spine surgery was evaluated as ‘0.75% ropivacaine’ and ‘untreated’ controls. SUMMARY OF LITERATURE REVIEW: Postoperative acute pain is major surgical side effect that lead to the deterioration of the quality of life. Traditional pain control results in variable side effects, and multimodal pain management has been recommended as an alternative. Local anesthetics is a short-acting time lower than 12 hours. There is controversy about the efficiency and stability of thermoreactive hydrogel products as a drug delivery system. MATERIALS AND METHODS: Patients scheduled for posterior spine surgery were enrolled by the inclusion criteria. In the treated group, PF-72 and ropivacaine mixture was injected to the surgical wound before closure. In control group 1, only 0.75% ropivacaine hydrochloride was injected. In the control group 2, the surgical site was without injection. Ten patients were randomly assigned to each group and standardized drugs for pain control were applied postoperatively and rescue regimens were applied when necessary. Postoperative pain score and the cumulative area under the curve (AUC) of pain score were compared. The percentage of subjects who were painless (pain score ≤ 3) was examined at each observation point. The first time of injection and the total dose of the rescue regimen were examined. Postoperative nausea and vomiting (PONV) were also evaluated. RESULTS: There was no significant difference in demographic data. The sum AUC of pain scores in the treated group was significantly lower than that in the control group 1 and 2 at all observation times. The proportion of painless patients was significantly higher in the treated group than in the control group 2. There was no significant difference between the first administration time and the total usage of the rescue regimen, and the percentage of patients with PONV at all time points. There was no statistically significant difference in the incidence of adverse events. CONCLUSIONS: PF-72 and ropivacaine mixture showed significant effects for pain management up to 72 hours postoperatively for the patients who underwent posterior spinal surgery without fatal complications.

Comparison of Cortical Ring Allograft and Plate Fixation with Autologous Iliac Bone Graft for Anterior Cervical Discectomy and Fusion

STUDY DESIGN: A retrospective cohort study. PURPOSE: To compare the clinical and radiological outcomes of patients who underwent anterior cervical discectomy and fusion (ACDF) supplemented with plate fixation using allograft with those who underwent ACDF using tricortical iliac autograft. OVERVIEW OF LITERATURE: As plate fixation is becoming popular, it is reported that ACDF using allograft may have similar outcomes compared with ACDF using autograft. METHODS: Forty-one patients who underwent ACDF supplemented with plate fixation were included in this study. We evaluated 24 patients who used cortical ring allograft filled with demineralized bone matrix (DBM) (group A) and 17 patients who used tricortical iliac autograft (group B). In radiological evaluations, fusion rate, subsidence of grafted material, cervical lordosis, fused segmental lordosis, and radiological adjacent segment degeneration (ASD) were observed and analyzed with preoperative and postoperative plain radiographs. Clinical outcomes were evaluated using the Neck Disability Index score, Odom criteria, and Visual Analog Scale score of neck and upper extremity pain. Radiological union was determined by dynamic radiographs using cutoff values of 1 mm of interspinous motion as the indication of pseudarthrosis. RESULTS: There was no significant difference in the fusion rate, graft subsidence, cervical lordosis, fused segmental lordosis, and ASD incidence between the groups. Operative time was shorter in group A (136 min) than in group B (141 min), but it was not significant (p>0.05). Blood loss was greater in group B (325 mL) than in group A (210 mL, p=0.013). There was no difference in the clinical outcomes before and after surgery. CONCLUSIONS: In ACDF with plate fixation, cortical ring allograft filled with DBM group showed similar radiological and clinical outcomes compared with those of the autograft group. If the metal plate is reinforced, using cortical ring allograft could be a viable alternative to autograft.

Comparison of the Efficacy and Safety Profiles of a Mixed ‘PF-72’ and ‘0.75% Ropivacaine HCl’ Versus a ‘0.75% Ropivacaine HCl’ and No Treatment Group: A Randomized, Single-Blind, Single-Institution Pilot Study

OBJECTIVES@#The efficacy and safety of ‘PF-72’ for management of postoperative acute pain through a mixed ‘PF-72’ and 0.75% ropivacaine hydrochloride solution in patients with posterior spine surgery was evaluated as ‘0.75% ropivacaine’ and ‘untreated’ controls.SUMMARY OF LITERATURE REVIEW: Postoperative acute pain is major surgical side effect that lead to the deterioration of the quality of life. Traditional pain control results in variable side effects, and multimodal pain management has been recommended as an alternative. Local anesthetics is a short-acting time lower than 12 hours. There is controversy about the efficiency and stability of thermoreactive hydrogel products as a drug delivery system.@*MATERIALS AND METHODS@#Patients scheduled for posterior spine surgery were enrolled by the inclusion criteria. In the treated group, PF-72 and ropivacaine mixture was injected to the surgical wound before closure. In control group 1, only 0.75% ropivacaine hydrochloride was injected. In the control group 2, the surgical site was without injection. Ten patients were randomly assigned to each group and standardized drugs for pain control were applied postoperatively and rescue regimens were applied when necessary. Postoperative pain score and the cumulative area under the curve (AUC) of pain score were compared. The percentage of subjects who were painless (pain score ≤ 3) was examined at each observation point. The first time of injection and the total dose of the rescue regimen were examined. Postoperative nausea and vomiting (PONV) were also evaluated.@*RESULTS@#There was no significant difference in demographic data. The sum AUC of pain scores in the treated group was significantly lower than that in the control group 1 and 2 at all observation times. The proportion of painless patients was significantly higher in the treated group than in the control group 2. There was no significant difference between the first administration time and the total usage of the rescue regimen, and the percentage of patients with PONV at all time points. There was no statistically significant difference in the incidence of adverse events.@*CONCLUSIONS@#PF-72 and ropivacaine mixture showed significant effects for pain management up to 72 hours postoperatively for the patients who underwent posterior spinal surgery without fatal complications.

Quality of Life in Patients with Osteoporotic Vertebral Compression Fractures

BACKGROUND: This study aimed to evaluate quality of life (QOL) using the EuroQOL-5 dimensions (EQ-5D) index and to examine factors affecting QOL in patients with an osteoporotic vertebral compression fracture (OVCF). METHODS: This ambispective study used a questionnaire interview. Patients over 50 years old with an OVCF at least 6 months previously were enrolled. Individual results were used to calculate the EQ-5D index. Statistical analysis was performed, and factors related to QOL were examined. RESULTS: Of 196 patients in the study, 84.2% were female, with an average age of 72.7 years. There were 66 (33.7%) patients with multilevel fractures. Conservative management was used in 75.0% of patients, and 56.1% received anti-osteoporosis treatment. The mean EQ-5D index was 0.737±0.221 and was significantly correlated with the Oswestry disability index score (correlation coefficient −0.807, P<0.001). The EQ-5D index was significantly correlated with age (Spearman's rho=−2.0, P=0.005), treatment method (P=0.005), and history of fracture (P=0.044) on univariate analysis and with conservative treatment (P<0.001) and osteoporotic treatment (P=0.017) on multivariate analysis. CONCLUSIONS: OVCF markedly lowers QOL in several dimensions for up to 12 months, even in patients who have healed. Treatment of osteoporosis and conservative treatment methods affect QOL and should be considered in OVCF management.

A Long, Solitary, Rosary-Shaped Spinal Neurofibroma

STUDY DESIGN: Case report. OBJECTIVES: We report the case of a long, solitary, rosary-shaped neurofibroma that was misdiagnosed as another disease due to the patient's surgical history involving repetitive procedures and its abnormal appearance. SUMMARY OF LITERATURE REVIEW: Neurofibroma is an intradural-extramedullary spinal tumor. It is generally not difficult to diagnose due to its frequent occurrence and specific magnetic resonance imaging (MRI) findings. However, to date, neurofibromatosis stigmata and long, solitary, rosary-shaped neurofibromas have rarely been reported. MATERIALS AND METHODS: A 60-year-old woman was admitted to our hospital due to persistent pain, despite previous surgery and repetitive procedures. On physical examination, vision loss, hearing loss, skin discoloration, or subcutaneous nodules were not observed. A neurologic examination revealed normal motor and sensory function and voiding sensation. No pathologic reflexes such as the Babinski sign were observed. Previous sequential MRIs revealed intradural lesions that progressed from the thoracic vertebra 11 to the lumbar vertebra 3. She had no signs of neurofibromatosis stigmata, and the neurologic examination was unremarkable. The initial diagnosis was based on serial MRIs, which revealed a parasite infestation, a spinal cord tumor (myxopapillary-type ependymoma with hemorrhage), arachnoiditis, and vascular malformations. Total mass excision was performed, and the final diagnosis was neurofibroma. RESULTS: There were no signs of a tumor remnants or local recurrence in a 1-year follow-up MRI study. CONCLUSIONS: Although intradural spinal tumors are very rare, their clinical features are nonspecific and resemble other degenerative spinal diseases, including spinal stenosis and disc herniation. These diseases may easily be overlooked by physicians.

Outcomes of Degenerative Lumbar Spine Surgery in Patients with Chronic Kidney Disease Undergoing Hemodialysis

STUDY DESIGN: Retrospective study. OBJECTIVES: To analyze the outcomes of degenerative lumbar spine surgery in patients undergoing hemodialysis due to chronic kidney disease (CKD). SUMMARY OF LITERATURE REVIEW: Patients who undergo hemodialysis due to chronic renal disease tend to exhibit accelerated changes in bone quality, deterioration of spinal stenosis, and accompanying neurological degeneration. The surgical treatment of chronic spinal diseases is also becoming more necessary with the increased lifespan of these patients. MATERIALS AND METHODS: We reviewed the medical records and radiographs of patients with CKD undergoing hemodialysis who were followed-up for more than 1 year after posterior lumbar spinal surgery. We evaluated clinical, laboratory, and radiologic variables. For a comparative analysis, patients were classified into subgroups according to age (65 years old), duration of hemodialysis (10 years), and type of surgery (simple decompression or fusion). RESULTS: We included 21 patients (5 men, 16 women) with a mean age of 66.2 years (range, 48-87 years). The mean duration of hemodialysis and follow-up was 18.9 years and 43 months, respectively. Decompressions with fusion were performed in 11 patients and simple decompressions in the other 10. The mean visual analog scale (VAS) of leg pain and the Oswestry Disability Index (ODI) significantly improved after surgery at time of the last follow-up; meanwhile, the mean VAS score for lower back pain did not show a statistically significant improvement. The postoperative ODI was correlated with age (correlation coefficient=0.71, p=0.006). In patients less than 65 years old, the ODI improvement was greater (p=0.035) than in those 65 years of age or older. There was no significant difference in the clinical outcomes according to the duration of hemodialysis. Complications were observed in 11 patients (52.4%, 7 in fusion and 4 in simple decompression), of which 2 cases were infections, and reoperations were performed in 5 patients. The union rate of the fusion cases at the 1-year follow-up was 81.8%. CONCLUSIONS: Appropriate spine surgery improved radicular pain and the ODI in patients with degenerative lumbar disease undergoing hemodialysis. However, postoperative complications were frequent and the improvement of clinical outcomes was minimal, especially in patients over 65 years of age and in those who underwent fusion. Therefore, the surgical treatment of patients with chronic renal disease undergoing hemodialysis requires adequate consideration of age and the duration of hemodialysis.

Analysis of Factors Affecting Postoperative Loss of Reduction in Unstable Thoracolumbar Fractures

STUDY DESIGN: Retrospective analysis OBJECTIVES: Loss of fracture reduction after posterior surgery to treat unstable thoracolumbar fractures can cause several complications. We analyzed the factors influencing postoperative loss of reduction. SUMMARY OF LITERATURE REVIEW: Controversy exists about the factors causing postoperative loss of reduction in thoracolumbar fractures during the follow-up period. MATERIALS AND METHODS: We analyzed the records of 59 patients who underwent posterior surgery for thoracolumbar unstable fractures and had completed a minimum follow-up of 1 year. Postoperative loss of reduction was defined as 30% or more loss of vertebral body height or 15° or more progression of the kyphotic angle at the 1-year follow-up compared to immediately after surgery. The associations between the patients??gender, age, level of fracture, injury of the posterior column, initial loss of fractured vertebral body height, load-sharing score, Thoraco-Lumbar Injury Classification and Severity score, number of fixed segments, type of pedicle screws, degree of postoperative reduction, degree of postoperative corrected kyphotic angle, changes in the insertion angle of the most proximal and the most distal pedicle screws, decreases in the upper and lower disc height of the fractured vertebral body, and postoperative loss of reduction were analyzed. RESULTS: Thirteen patients (22.0%) had postoperative loss of reduction. Age at the time of the operation (p=0.034), initial loss of fractured vertebral body height (p=0.042), and changes in the insertion angles of the most distal pedicle screws (p=0.021) were significantly associated with postoperative loss of reduction. However, the other factors did not show a significant relationship. CONCLUSIONS: In patients who underwent posterior surgery for unstable thoracolumbar fractures, the frequency of loss of reduction was high in patients more than 45 years old at the time of the operation, with a 50% or more loss of the initial fractured vertebral body height, and with changes of 5° or more in the insertion angles of the most distal pedicle screws.

Comparative Analysis of Revision Surgery Groups between within 5 Years and More than 10 Years after Lumbar Spinal Fusion Due to Adjacent Segment Disease / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to analyze the risk factors for early adjacent segment disease (EASD) in patients undergoing revision surgery within 5 years from the first operation as compared with those after more than 10 years. MATERIALS AND METHODS: A total of 755 patients with degenerative lumbar disease underwent lumbar spinal fusion of 3 or less segments between August, 1988 and May, 2009. Of these, 44 patients underwent revision surgery due to adjacent segment disease (ASD) until May, 2014. These patients presented with ASD, 19 and 13 of whom underwent revision surgery within 5 years and after more than 10 years of the first one, and were thus assigned to group A (n=19) and group B (n=13), respectively. Thirty-two of these patients were enrolled in this study and baseline and clinical characteristics, including sex, age, fusion method, preoperative diagnosis, the number of fused segments, fusion level, and radiological measurements were compared between the two groups. Radiological measurements included pre- and postoperative lumbar lordotic angle (LLA), pre- and postoperative fusion segment lordotic angle (FSLA), pre- and postoperative FSLA per level and the correction of LLA, FSLA, and FSLA per level. For statistical analysis, univariate analysis with the chi-square test was performed using SPSS 14.0. RESULTS: In group A, the number of patients undergoing posterior lumbar interbody fusion (PLIF) rather than posterolateral fusion, those with postoperative FSLA per level of <20° and the adjacent segment levels to L4-5 and L5-S1 was significantly larger compared with group B (p=0.018, 0.046, and 0.009, respectively. CONCLUSION: In conclusion, our results indicate that the degree of risk of EASD was relatively higher in association with PLIF, postoperative FSLA per level of <20° and the adjacent segment levels to L4-5 and L5-S1.

Unusual Presentation of Bilateral Foraminal Disc Herniation

A 64-year-old woman was admitted to Soonchunhyang University Seoul Hospital due to the aggravation of bilateral radicular pain for one month prior to her visit. She had a 30 years history of low back pain and intermittent bilateral radiating pain. A magnetic resonance imaging scan revealed a bilateral space-occupying lesion in the L5 foramen. A sagittal computed tomography scan showed a disc space-narrowing, vacuum-containing, and widening of the neural exit foramen with thinning of the pedicle and posterior vertebral body scalloping. An axial scan showed that the space-occupying lesion contained calcification and had eroded the surrounding bony structure. During surgical exploration, the atrophic L5 nerve root was identified over the mass-like lesion, and the lesion was shown to be a result of a hard, extruded disc fragment. A bilateral foraminal disc is a very rare condition that when it progresses chronically and gradually, can erode adjacent bony structures. Specific precautions are necessary during fusion surgery with a pedicle screw.

Work-Related Musculoskeletal Disorders among Spine Surgeons / 대한정형외과학회잡지

PURPOSE: To investigate the prevalence and risk factors of musculoskeletal disorder (MSD) among spine surgeons. MATERIALS AND METHODS: A modified version of discomfort survey was sent via e-mail to surgeons that belong to the Korean Society of Spine Surgery. The survey questionnaires were composed of demographics, factors relating to spine surgery, and MSD. We investigated the common sites of occurrence of MSD and its risk factors. RESULTS: The survey was sent to a total of 420 subjects; of which, 80 subjects (19.0%) responded. About 78.8% of the respondents had MSD for the past year. The common sites of occurrence included the neck (52.5%), back (46.3%), and shoulder (18.8%). The prevalence of pain in the elbow joint/forearm was higher in the group performing a higher frequency of spine surgeries (p=0.033). Moreover, the prevalence of pain in the wrist/hand (p=0.008) and in the back (p=0.042) was higher in those with greater frequency of major surgeries (>10 case/year) as compared with those with lower frequency of major surgeries. CONCLUSION: As shown, about 78.8% of spine surgeons experienced MSD for the past one year. Its prevalence was higher as compared with the general population. Thus, more attention should be paid to the prevention of MSD among spine surgeons.

Awareness Assessment on Continuing Medical Education in Korean Orthopaedic Society / 대한정형외과학회잡지

PURPOSE: Awareness on continuing medical education (CME) of the Korean Orthopaedic Association (KOA) was investigated in order to augment the weak educational points of the conventional academic CME. MATERIALS AND METHODS: The web-survey was conducted in the KOA on the awareness of conventional academic or web-based CME. The questionnaire included working conditions, intimacy of informational technology, and strengths and weaknesses of academic and web-based CME. RESULTS: Among 3,427 emails sent, 168 (4.9% of effective response rate) responses were received. Of the responders, 74.4% of the responders could not attend CME frequently because of working time (35.7%) and a distance far from the working place (13.2%). The merits of academic CME included as the opportunity for considerations of other members' thoughts on some clinical matters (64.3%); however, the weak points were holding several similar conferences (60.1%) and too short time for adequate study (53.0%). They wanted that surgical procedures and tips (49.0%) to be provided in the form of lecture slides (44.6%) or movie clips (37.6%) in web-based CME. 95.5% of the responders showed positive response regarding the need for web-based CME. CONCLUSION: Results of the survey showed high needs and interests in web-based CME, which could support the weaknesses of the academic CME with less time for education and limited accessibility to CME due to time or space barriers due to their working conditions.

Risk Factors for Recurrent Lumbar Disc Herniations

The most common complication after lumbar discectomy is reherniation. As the first step in reducing the rate of recurrence, many studies have been conducted to find out the factors that may increase the reherniation risk. Some reported factors are age, sex, the type of lumbar disc herniation, the amount of fragments removed, smoking, alcohol consumption and the length of restricted activities. In this review, the factors studied thus far are summarized, excepting factors which cannot be chosen or changed, such as age or sex. Apart from the factors shown here, many other risk factors such as diabetes, family history, history of external injury, duration of illness and body mass index are considered. Few are agreed upon by all. The reason for the diverse opinions may be that many clinical and biomechanical variables are involved in the prognosis following operation. For the investigation of risk factors in recurrent lumbar disc herniation, large-scale multicenter prospective studies will be required in the future.

A comparison of Decompression and Fusion Surgery in Lumbar Degenerative Spondylolisthesis

STUDY DESIGN: A retrospective, controlled study. OBJECTIVES: To assess clinical and radiologic results of decompression without fusion surgery in the treatment of stable lumbar degenerative spondylolisthesis (LDS) and to compare clinical outcomes of fusion surgery. SUMMARY OF LITERATURE REVIEW: Although it is reported that decompression surgery is effective in treating LDS, few reports have compared the outcomes of treatment using decompression and instrumented fusion. MATERIALS AND METHODS: A retrospective study was performed and fifty eight degenerative spondylolisthesis patients who received decompression treatment with or without fusion surgery with follow up for at least 2 years were included. The number of patients in the decompression and fusion groups were 23 each and they were selected with age and slip degree taken into account. Clinical factors were evaluated using the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) of the back/leg and high risk of operation. Radiological factors were evaluated such as slippage, angulation, and disc height at the affected level in preoperative and final follow up. RESULTS: There was no statistical difference between the decompression and fusion groups in the VAS of the back/leg, slippage, and high risk of operation preoperatively (p>0.05). The mean operative time was 73.9 minutes in the decompression group and 123.7 minutes in the fusion group. The mean blood loss was 134.5mL in the decompression group and 323.5mL in the fusion group. VAS of the back/leg and ODI improved in both groups and there were no significant differences between the two groups statistically. CONCLUSIONS: Decompression with/without fusion had a favorable clinical outcome in stable degenerative spondylolisthesis patients. However, fusion involves more operative time and blood loss compared to simple decompression. Simple decompression is a good treatment option, especially in operative high risk patients.

Conus Medullaris Syndrome Caused by Delayed Recollapse after Surgery of Burst Fracture: A Case Report

STUDY DESIGN: A case report. OBJECTIVES: Lumbar burst fracture was treated with operation, which delayed recollapse of L1 and led to conus medullaris syndrome. SUMMARY OF LITERATURE REVIEW: After operation, conus medullaris syndrome causing by delayed recollapse is not frequently reported. MATERIALS AND METHODS: A 56-year-old male was admitted with lower back pain caused by a fall. Radiologic findings showed L1 burst fracture with about 42% of height loss. There was no neurologic deficit. Posterior fusion was performed using instrumentation. Five weeks after the operation, the patient was admitted for urination and defecation difficulty. Radiologic findings showed that the L1 had recollapsed with about 38% of height loss. To resolve the problem, anterior surgery was performed. RESULTS: Two years after surgery, bladder and anal sphincter dysfunction wasn't recovered. CONCLUSIONS: Lumbar burst fracture should be follow up carefully until union of the fracture because burst fracture leads to delayed recollapse.