Posterior Surgery with Selective Anterior Reinforcement and Screw Augmentation for a Delayed Myelopathy from an Osteoporotic Vertebral Compression Fracture / 대한정형외과학회잡지

Purpose@#In delayed myelopathy (DM) from osteoporotic vertebral compression fractures (OVCF), the mechanisms of spinal cord impingement differ according to the stability of the fractured vertebra. This study examined the availability of a posterior surgery comprised of pedicle screw augmentation with polymethylmethacrylate (PMMA) and selective anterior reinforcement (PS-PMMA+SAR) according to the stability. @*Materials and Methods@#This was a retrospective single-center study. The consecutive patients who had a PS-PMMA+SAR for a DM from OVCF and were followed up more than two years were reviewed. Thirty patients were eligible for this study. All patients used fenestrated screws for PMMA augmentation. Anterior reinforcement was selected according to the stability. The unstable type was done by filling the vacuum cleft with bone chips or PMMA, and the stable type was done by vertebral body anterior translation with/without an interbody bone graft. The radiological and functional outcomes were evaluated. @*Results@#There were 20 unstable and 10 stable cases. The regional kyphotic angle was improved significantly from 31.3°±10.8° to 10.4°±8.3° (p<0.001). The anterior vertebral height ratio was improved significantly from 39.4%±17.1% to 86.4%±9.2% (p<0.001). The spinal canal invasion ratio was improved significantly from 39.2%±14.8% to 19.1%±10.8% (p<0.001). The walking ability was improved mostly by two Nurick’s grades (p<0.001). The Oswestry disability index was improved from 72% to 33% (p<0.001). @*Conclusion@#Posterior surgery with PMMA-augmented pedicle screws, and selective anterior reinforcement for DM from OVCF was available to achieve a good functional and radiological outcome.

Vertebral Body Anterior Translation, a Novel Technique for Delayed Myelopathy Due to Osteoporotic Spine Fractures

Background@#Osteoporotic vertebral compression fractures (OVCFs) are often associated with delayed myelopathy. Surgical treatment of delayed myelopathy following an OVCF comprises spinal canal decompression and stable fixation of the vertebral column with an acceptable sagittal alignment. However, such surgical methods are not usually feasible because of medical comorbidities and osteoporosis. We devised a novel, simple technique to decompress the spinal canal and reconstruct the middle column by translating the fractured vertebral body anteriorly through a posterior approach and verified the validity of the new technique. @*Methods@#We conducted a single-center, retrospective study. Patients who underwent vertebral body anterior translation (VBaT) between 2014 and 2017 due to delayed myelopathy after OVCFs were included. Through a posterior approach, discs between the fractured vertebra and the adjacent vertebrae were released. The fractured vertebra was translated anteriorly with pedicle screws and rods to realign the middle column. Radiological and functional improvement was analyzed. @*Results@#There were 12 consecutive patients. The mean age was 70.3 ± 9.4 years. There were 8 female and 4 male patients. Follow-up period was 35.9 ± 13.1 months. Nine patients had pedicle screw augmentation with polymethyl methacrylate. The mean number of fusion segments was 3.4 (range, 2–4). There were 3 types of spinal canal invasion. Five patients had vertebral body vacuum clefts with posterior wall fractures. Five patients had vertebral body angulation with endplate protrusion. Two patients had 3 column fractures. In radiological analysis, the regional kyphotic angle was 35.1° ± 9.1° preoperatively and improved to 8.8° ± 6.8° postoperatively and 9.8° ± 6.1° at the final follow-up (p < 0.001). The anterior vertebral body height ratio was 27.6% ± 7.0% preoperatively and improved to 80.5% ± 13.7% postoperatively and 83.7% ± 12.5% at the final follow-up (p < 0.001). The spinal canal invasion ratio was 52.6% ± 9.1% preoperatively and improved to 25.2% ± 10.4% postoperatively (p < 0.001). Neurological deficit was improved in all patients by 1–3 grades according to Nurick’s grading system. @*Conclusions@#In delayed myelopathy following an OVCF, although the posterior cortex invades the spinal canal, it is usually already in the union state. Therefore, it can bear compression force as a middle column if realigned to be in line with the adjoining vertebrae. VBaT demonstrated satisfactory reduction of kyphosis and maintenance of stability until the last follow-up.

Influence of Epidural Steroid Injection on Adrenal Function

BACKGROUND: Spinal diseases are self-limited or non-progressive in many cases. Epidural steroid injection (ESI) is a common nonsurgical treatment option for spinal pain. Despite concerns about complications of repeated steroid injection, few studies reported on the adrenal function of spine disease patients undergoing surgery after ESI. We investigated the influence of preoperative multiple ESIs on adrenal function in spine surgery patients. METHODS: This was a retrospective study with prospective data collection. Those who underwent elective spinal operations and had a history of multiple ESIs from January to June 2017 were selected as a study group. Those who underwent knee arthroplasty and did not have a history of ESI and any kind of steroid injection in other areas during 6 months before surgery were selected as a control group. Demographic data were compared to assess homogeneity between groups. We assessed the preoperative serum cortisol level (SCL) to compare the basal adrenal function between groups. Also, we assessed the elevation of SCL postoperatively to evaluate the adrenal response to the surgical stress in each group. For subgroup analysis, we divided all patients into normal (7–28 µg/dL) and subnormal groups according to SCL and analyzed risk factors of adrenal suppression with multivariate logistic regression test. RESULTS: There were 53 patients in the study group and 130 in the control group. Age and sex were homogeneous between groups. There was significant intergroup difference in preoperative SCL (10.4 ± 4.8 µg/dL in the study group vs. 12.0 ± 4.2 µg/dL in the control group; p = 0.026).The postoperative day one SCL was 11.6 ± 5.0 µg/dL in the study group without significant increase from the preoperative level (p = 0.117), whereas the increase was significant in the control group with a postoperative level of 14.4 ± 4.4 µg/dL (p < 0.001). Among all patients, the SCL was subnormal in 18 patients and within the normal range in 165. Spine surgery was the independent risk factor irrespective of age and sex (odds ratio, 3.472; p = 0.015). CONCLUSIONS: Our results suggest that concern should be raised about the influence of preoperative multiple ESIs on adrenal suppression in spine surgery patients.

Influences of Computer Works on Blink Rate and Ocular Dryness in Adolescents

PURPOSE: To evaluate the change in blink rate in adolescents according to the type and duration of computer tasks and to analyze the risk of ocular dryness using an ocular protection index. METHODS: Fifteen male high school students played computer games and viewed Internet lectures for 20 minutes each. Blink rate was measured by USB camera, and ocular protection index (OPI, the ratio of BUT to inter-blink interval) was calculated for each subject during the two tasks. In addition, 7 of the 15 subjects played computer games again for 40 minutes on another day, and the change in blink rate according to the duration of computer games was observed. RESULTS: The average blink rate was 5.44+/-3.29 per minute (median 5, range 2-12.75) while playing computer games and 20.63+/-11.21 per minute (median 18.25, range 4.93-42.2) while viewing Internet lectures, and this difference was statistically significant (p=0.001). The percentage of subjects with OPI values less than 1 was 53% for computer games and 13% for Internet lectures (p=0.025). While playing computer games for 40 minutes, the mean of total blinks during ten-minute intervals decreased over time: 59.43 times (median 57) during the first 10 minutes, 33.86 times (median 41) during the last 10 minutes. CONCLUSIONS: The blink rate in adolescents was significantly lower and the risk of ocular dryness was higher while playing computer games compared with that of viewing internet lectures. As playing time increased, the blink rate decreased and risk of ocular dryness increased.