Predicting Bone Marrow Edema and Fracture Age in Vertebral Fragility Fractures Using MDCT.

OBJECTIVE. The purpose of this study was to evaluate whether CT features can predict bone marrow edema (BME) on MRI and fracture age in vertebral fragility fractures. MATERIALS AND METHODS. A total of 189 thoracolumbar compression fractures in 103 patients (14 men, 89 women; mean age, 76 years) imaged with both spine CT and MRI were retrospectively included. The presence and extent of BME were assessed on MRI to divide fractures into those with and without BME. The group with BME was then classified for subgroup analysis into fractures with extensive BME (comprising 50% or more of the vertebral body) and those with BME comprising less than 50% of the vertebral body. On CT, five features (presence of cortical or endplate fracture line, presence of trabecular fracture line, presence of condensation band, change in trabecular attenuation, and width of paravertebral soft-tissue change) were analyzed. RESULTS. All five CT findings were predominantly seen in fractures with BME (p < 0.001). Elevated trabecular attenuation, presence of a cortical or endplate fracture line, and paravertebral soft-tissue width showed excellent diagnostic indication for fractures with BME (ROC AUCs: 0.990, 0.976, and 0.950, respectively). In the subgroup with extensive BME, paravertebral soft-tissue width was significantly higher, whereas the change in trabecular attenuation was lower compared with those with BME comprising less than 50% of the vertebral body (p < 0.001). When BME was present, fracture age was not significantly different between the two subgroups, and only greater trabecular attenuation elevation was predictive of older fracture age on linear mixed model analyses (p < 0.001). Interobserver agreement was good for the trabecular fracture line factor and excellent for all other factors. CONCLUSION. CT features accurately correlate with the presence and extent of BME in vertebral fragility fractures. Elevation of trabecular attenuation was the only significant image predictor of fracture age.

Paraspinal Lean Muscle Mass Measurement Using Spine MRI as a Predictor of Adjacent Segment Disease After Lumbar Fusion: A Propensity Score-Matched Case-Control Analysis.

OBJECTIVE. The purpose of this study was to compare paraspinal muscle mass between patients with and without adjacent segment disease (ASD) after lumbar fusion. MATERIALS AND METHODS. Fifty patients with ASD (mean age, 61.4 years; ratio of male to female patients: 13:37; mean body mass index [BMI; weight in kilograms divided by the square of height in meters], 25.1) were matched to 50 control patients on the basis of age, sex, BMI, and fusion segment. The total cross-sectional area (CSA) and functional CSA (FCSA; i.e., the area containing lean muscle tissue only) of the paraspinal muscle group (the multifidus and erector spinae muscles) and the psoas muscles were measured on preoperative MRI. The ratio of the FCSA to the total CSA and the skeletal muscle index (SMI; calculated as muscle area [expressed as centimeters squared] divided by the square of the patient's height in meters]) were calculated and compared between the two groups with use of the independent-sample t test. RESULTS. The mean FCSA (2178.6 mm2 vs 2594.0 mm2; p = 0.004), the ratio of the FCSA to the total CSA (45.4% vs 52.2%; p = 0.001), and the SMI of the FCSA (8.8 vs 10.6; p = 0.001) of the paraspinal muscle group were significantly smaller in patients with ASD compared to the control group. When the paraspinal and psoas muscle groups were combined, the mean FCSA (3680.8 mm2 vs 4268.2 mm2; p = 0.013), the ratio of FCSA to total CSA (53.3% vs 58.6%; p = 0.004), the SMI of the total CSA (27.7 vs 29.3; p = 0.049), and the SMI of the FCSA (14.9 vs 17.3; p = 0.002) were significantly lower in patients with ASD than in control patients. CONCLUSION. Patients with ASD had smaller lean muscle mass (FCSA), a lower ratio of FCSA to total CSA, and a lower SMI of the FCSA of the paraspinal muscle group on pre-operative MRI, compared with control patients.

Comparison among perfect-C®, zero-P®, and plates with a cage in single-level cervical degenerative disc disease.

BACKGROUND: We intended to analyze the efficacy of a new integrated cage and plate device called Perfect-C for anterior cervical discectomy and fusion (ACDF) to cure single-level cervical degenerative disc disease. METHODS: We enrolled 148 patients who were subjected to single-level ACDF with one of the following three surgical devices: a Perfect-C implant (41 patients), a Zero-P implant (36 patients), or a titanium plate with a polyetheretherketone (PEEK) cage (71 patients). We conducted a retrospective study to compare the clinical and radiological results among the three groups. RESULTS: The length of the operation, intraoperative blood loss, and duration of hospitalization were significantly lower in the Perfect-C group than in the Zero-P and plate-with-cage groups (P < 0.05). At the last follow-up visit, heterotopic ossification (HO) was not observed in any cases (0%) in the Perfect-C and Zero-P groups but was noted in 21 cases (30%) in the plate-with-cage group. The cephalad and caudal plate-to-disc distance (PDD) and the cephalad and caudal PDD/anterior body height (ABH) were significantly greater in the Perfect-C and Zero-P groups than in the plate-with-cage group (P < 0.05). Subsidence occurred in five cases (14%) in the Perfect-C group, in nine cases (25%) in the Zero-P group, and in 15 cases (21%) in the plate-with-cage group. Fusion occurred in 37 cases (90%) in the Perfect-C group, in 31 cases (86%) in the Zero-P group, and in 68 cases (95%) in the plate-with-cage group. CONCLUSIONS: The Perfect-C, Zero-P, and plate-with-cage devices are effective for treating single-level cervical degenerative disc disease. However, the Perfect-C implant has many advantages over both the Zero-P implant and conventional plate-cage treatments. The Perfect-C implant was associated with shorter operation times and hospitalization durations, less blood loss, and lower subsidence rates compared with the Zero-P implant or the titanium plate with a PEEK cage.

Reference Standards for Digital Infrared Thermography Measuring Surface Temperature of the Upper Limbs.

(1) Background: although digital infrared thermographic imaging (DITI) is used for diverse medical conditions of the upper limbs, no reference standards have been established. This study aims to establish reference standards by analyzing DITI results of the upper limbs. (2) Methods: we recruited 905 healthy Korean adults and conducted thermography on six regions (dorsal arm, ventral arm, lateral arm, medial arm, dorsal hand, and ventral hand region). We analyzed the data based on the proximity of regions of interest (ROIs), sex, and age. (3) Results: the average temperature (°C) and temperature discrepancy between the right and the left sides (ΔT) of each ROI varied significantly (p < 0.001), ranging from 28.45 ± 5.71 to 29.74 ± 5.14 and from 0.01 ± 0.49 to 0.15 ± 0.62, respectively. The temperature decreased towards the distal ROIs compared to proximal ROIs. The average temperatures of the same ROIs were significantly higher for men than women in all regions (p < 0.001). Across all regions, except the dorsal hand region, average temperatures tended to increase with age, particularly in individuals in their 30s and older (p < 0.001). (4) Conclusions: these data could be used as DITI reference standards to identify skin temperature abnormalities of the upper limbs. However, it is important to consider various confounding factors, and further research is required to validate the accuracy of our results under pathological conditions.

Reference Standard for Digital Infrared Thermography of the Surface Temperature of the Lower Limbs.

Digital infrared thermographic imaging (DITI) is a supplementary diagnostic technique to visualize the surface temperature of the human body. However, there is currently no reference standard for the lower limbs for accurate diagnosis. In this study, we performed DITI on the lower limbs of 905 healthy Korean volunteers (411 males and 494 females aged between 20 and 69 years) to obtain reference standard data. Thermography was conducted on the front, back, lateral sides, and sole area, and 188 regions of interest (ROIs) were analyzed. Additionally, subgroup analysis was conducted according to the proximity of ROIs, sex, and age groups. The mean temperatures of ROIs ranged from 24.60 ± 5.06 to 28.75 ± 5.76 °C and the absolute value of the temperature difference between both sides reached up to 1.06 ± 2.75 °C. According to subgroup analysis, the sole area had a significantly lower temperature than any other areas, men had higher temperatures than women, and the elderly had higher temperatures than the young adults except for the 20s age group (p < 0.001, respectively). This result could be used as a foundation for the establishment of a reference standard for DITI. Practical patient DITI can be accurately interpreted using these data, and it can serve as a basis for further scientific research.

Differential Screening of Herniated Lumbar Discs Based on Bag of Visual Words Image Classification Using Digital Infrared Thermographic Images.

Doctors in primary hospitals can obtain the impression of lumbosacral radiculopathy with a physical exam and need to acquire medical images, such as an expensive MRI, for diagnosis. Then, doctors will perform a foraminal root block to the target root for pain control. However, there was insufficient screening medical image examination for precise L5 and S1 lumbosacral radiculopathy, which is most prevalent in the clinical field. Therefore, to perform differential screening of L5 and S1 lumbosacral radiculopathy, the authors applied digital infrared thermographic images (DITI) to the machine learning (ML) algorithm, which is the bag of visual words method. DITI dataset included data from the healthy population and radiculopathy patients with herniated lumbar discs (HLDs) L4/5 and L5/S1. A total of 842 patients were enrolled and the dataset was split into a 7:3 ratio as the training algorithm and test dataset to evaluate model performance. The average accuracy was 0.72 and 0.67, the average precision was 0.71 and 0.77, the average recall was 0.69 and 0.74, and the F1 score was 0.70 and 0.75 for the training and test datasets. Application of the bag of visual words algorithm to DITI classification will aid in the differential screening of lumbosacral radiculopathy and increase the therapeutic effect of primary pain interventions with economical cost.

Minimally Invasive Spine Surgery With Midline Cortical Bone Trajectory Screw Fixation for Lumbar Degenerative Disease in a Retrospective Study of 200 Patients.

OBJECTIVE: Midline lumbar interbody fusion is performed for treatment of various lumbar degenerative diseases, with good clinical outcomes and few complications. However, there are no large-scale or long-term studies regarding midline lumbar interbody fusion. Therefore, the purpose of this study was to evaluate the clinical results of midline lumbar interbody fusion and to compare the results according to surgical level. METHODS: Between January 2013 and December 2015, 200 patients with lumbar degenerative disease undergoing midline lumbar interbody fusion surgery were enrolled. The mean patient age was 69.9 ± 15.8 years (range, 40-85 years). The patients were divided into groups according to surgical level: (1) level 1 operation (136 patients), (2) level 2 operation (43 patients), (3) level 3 operation (12 patients), and (4) level 4 or higher (9 patients). Clinical outcomes, fusion rates, and complications were compared among the 4 groups. RESULTS: All clinical outcomes significantly improved after surgery (measured at 3 years postoperatively) in all groups. Mean fusion rate was 90.5% ± 5.21%. Fusion rate was highest in group I (95.8%) and lowest in group IV (85.2%). There were complications in 17 cases (8.5%). Adjacent segment disease occurred in 16 cases, 5 of which required surgery. Group 1 had 1 case, and group 4 had 4 cases. Screw loosening occurred in 1 case in group 4. There were no cases of infection or mechanical complications. CONCLUSION: This large, single-institution, retrospective study demonstrates favorable clinical outcomes after midline lumbar interbody fusion for lumbar degenerative disease regardless of surgical level.

Surgical Outcomes of Dysphagia Provoked by Diffuse Idiopathic Skeletal Hyperostosis in the Cervical Spine.

PURPOSE: This study aimed to predict the surgical outcomes of diffuse idiopathic skeletal hyperostosis (DISH)-related dysphagia (DISH-phagia) and to evaluate the importance of prevertebral soft tissue thickness (PVST). MATERIALS AND METHODS: In total, 21 surgeries (anterior osteophytectomy or anterior cervical decompression and fixation) were included in this study for DISH-phagia from 2003 to 2019. Clinical outcomes were assessed using the Dysphagia Outcome and Severity Scale (DOSS) preoperatively, at 1 month postoperatively, and last follow up (mean 29.5 months). PVST was measured using lateral plain radiographs. Paired t-test and Spearman's correlation test was used to identify relationships between various PVST indices and DOSS. RESULTS: Comparisons were made from 17 patients out of 21, in which the record had all of three measurements. The narrowest PVST preoperatively was 2.55±0.90 mm, with a DOSS score of 4.47±1.61, and that at 1 month after surgery was 5.02±2.33 mm, with a DOSS score of 6.12±1.32. At last follow up, PVST and DOSS values were 3.78±0.92 mm and 5.82±1.34, and three patients experienced symptom relapse. Significant relationships were found between PVST and DOSS at all time points: before surgery (R=0.702, p<0.001), 1 month after surgery (R=0.539, p=0.012), and last follow up (R=0.566, p=0.020). CONCLUSION: Surgical removal of anterior osteophytes is an effective treatment option for DISH-phagia, and PVST is a useful parameter in DISH-phagia. The goal of DISH surgery should be to remove DISH as much as possible to ensure sufficient PVST postoperatively.

Nitinol spring rod dynamic stabilization system and Nitinol memory loops in surgical treatment for lumbar disc disorders: short-term follow up.

OBJECT: The purpose of this study was to analyze the usefulness of the BioFlex, a Nitinol spring rod dynamic stabilization system, and the Nitinol shape memory loop (KIMPF-DI Fixing System) as a posterior dynamic stabilization system in surgery for low-back pain. METHODS: The 103 patients who underwent treatment with the BioFlex system were divided into two groups: Group 1, dynamic stabilization with or without posterior lumbar interbody fusion (PLIF); and Group 2, rigid fixation (PLIF + BioFlex system only). A total of 66 segments were treated with only the BioFlex system; in these the preoperative range of motion (ROM) was 10.0 +/- 4.3 degrees , which changed to 4.1 +/- 1.9 degrees after surgery. Adjacent-segment ROM changed from 8.4 +/- 3.4 degrees to 10.7 +/- 3.2 degrees in Group 1 and from 6.5 +/- 3.2 degrees to 10.5 +/- 4.6 degrees in Group 2 postoperatively. A total of 110 segments received both BioFlex and PLIF, with a fusion rate of 90.0%. The visual analog scale score for back pain improved from 7.3 +/- 3.1 to 1.4 +/- 1.8 in Group 1 and from 7.4 +/- 2.4 to 2.1 +/- 2.3 in Group 2. The Oswestry Disability Index improved from 35.2 +/- 6.4 to 12.1 +/- 4.5 in Group 1 and from 37.8 +/- 5.7 to 13.6 +/- 4.2 in Group 2. (The ROM and assessment scores expressed are the mean +/- standard deviation.) The 194 patients in whom Nitinol memory loops were implanted were analyzed based on the preoperative and 1-year postoperative ROM of each lumbar segment. The change of ROM in looped segments treated with PLIF was significantly reduced, but the change of ROM in looped segments without PLIF was not significant. The change of ROM at the segment adjacent to the loop was not significant, and the change of kyphosis reflected a slight recovery. CONCLUSIONS: The Nitinol BioFlex dynamic stabilization system can achieve stabilization and simultaneously allow physiological movement, which can in turn decrease the degeneration of adjacent segments. When used with PLIF, the fusion rate can be expected to increase. The flexible Nitinol shape memory loop, a posterior dynamic stabilization device, is an adequate tension band that displays strength similar to the posterior ligamentous structures. In combination with PLIF at the main lesion, the BioFlex system or the Nitinol memory loop can provide posterior dynamic stabilization to the transitional upper or lower segments, enhance the fusion rate, reduce the adjacent segment degeneration, and provide dynamic stabilization of the spine.

Decompression alone versus fusion for pyogenic spondylodiscitis.

BACKGROUND CONTEXT: A spinal infection is a serious problem for a spine surgeon, and there is currently much debate regarding how best to treat pyogenic spondylodiscitis using antibiotics and the instrumentations that have been developed to date. PURPOSE: The purpose of this study was to determine which method is better for treating pyogenic spondylodiscitis. STUDY DESIGN: A retrospective chart review was performed. PATIENT SAMPLE: Thirty-one patients with pyogenic spondylodiscitis underwent surgical treatment between 2000 and 2016 at the authors' institution. OUTCOME MEASURES: Clinical outcomes were assessed using a visual analog scale (VAS). We measured translation and rotation on flexion and extension X-rays to identify instability. METHODS: Patients were divided into two groups: Group I, decompression group; Group II, decompression plus fusion group. Group I exhibited no instability according to a preoperative radiographic study, whereas Group II exhibited instability. Both groups were compared with respect to demographics and laboratory findings, including tests to determine C-reactive protein (CRP) levels and erythrocyte sedimentation rates (ESR), organisms, and the total duration of antibiotic treatment after the operation. We compared the results of the preoperative, postoperative, and last follow-up radiographic examinations of the sagittal alignment of the infected segment. This study was supported by a clinical research fund (4,500 dollars) from the National Health Insurance Service, Ilsan Hospital. RESULTS: A total of 31 patients were included; 22 (71%) were in Group I and 9 (29%) were in Group II. On radiological examination, the mean preoperative translation and rotation values in Group I were 2.45±1.22 mm and 5.64±1.98°, and in Group II were 5.35±1.65 mm and 12.01±4.22°. At the last follow-up, the mean translation and rotation values in Group I were 1.95±1.75 mm and 2.69±1.61°, and in Group II were 1.77±1.02 mm and 3.44±2.07°. Both Groups I and II exhibited stability after the operation. No differences were detected in preoperative ESR and CRP levels between the two groups. Group I, compared with Group II, experienced a shorter duration of treatment with antibiotics and normalization of ESR and CRP levels after the operation and a shorter hospitalization period. CONCLUSIONS: If the appropriate antibiotics are administered quickly when there is no instability, decompression alone is effective; however, if instability is detected, decompression plus fusion can be used to achieve stability.

Neurilemmoma of Deep Peroneal Nerve Sensory Branch : Thermographic Findings with Compression Test.

We report a case of neurilemmoma of deep peroneal nerve sensory branch that triggered sensory change with compression test on lower extremity. After resection of tumor, there are evoked thermal changes on pre- and post-operative infrared (IR) thermographic images. A 52-year-old female presented with low back pain, sciatica, and sensory change on the dorsal side of the right foot and big toe that has lasted for 9 months. She also presented with right tibial mass sized 1.2 cm by 1.4 cm. Ultrasonographic imaging revealed a peripheral nerve sheath tumor arising from the peroneal nerve. IR thermographic image showed hyperthermia when the neurilemoma induced sensory change with compression test on the fibular area, dorsum of foot, and big toe. After surgery, the symptoms and thermographic changes were relieved and disappeared. The clinical, surgical, radiographic, and thermographic perspectives regarding this case are discussed.

Anterior cervical fusion using dense cancellous allografts and dynamic plating.

OBJECTIVE: Dense cancellous grafts provide an open matrix for vascular and cellular penetration for early osseous integration. Thus, they provide a better biological fusion substrate than cortical or corticocancellous grafts. The aim of this study is to evaluate the efficacy of the dense cancellous allografts as a substrate for anterior cervical fusion along with instrumentation. METHODS: This is a retrospective study of 98 patients who underwent anterior cervical discectomy, fusion with dense cancellous allograft bone, and instrumentation using dynamic plating between January 2001 and March 2002. Of these procedures, 60 involved single-level and 38 involved two-level fusions. Subsidence was assessed by plain x-rays at 1, 3, 6, and 12 months and fusion at 3, 6, and 12 months after surgery. Fusion was defined as the appearance of bridging trabecular bone and absence of motion in flexion-extension films. RESULTS: The mean follow-up period was 15 months (range, 12-25 mo). Successful fusion was observed in 70, 84, and 96% of the patients at 3, 6, and 12 months, respectively. The average subsidences for single-level and two-level fusions were 2.0 and 3.2 mm, respectively. No allograft- or hardware-related complications were encountered in our series. CONCLUSION: Dense cancellous allografts are very effective as bone graft substitutes for achieving anterior cervical fusion along with instrumentation. Successful fusion was observed in 70% of our patients at 3 months, with a fusion rate of 96% at 1 year. These allografts provide an effective replacement for autologous grafts in cervical interbody fusion.

Surgical techniques for total sacrectomy and spinopelvic reconstruction.

The surgical management of sacral tumors requires partial or total sacrectomy and spinopelvic reconstruction. These lesions present a great surgical challenge, because most spine surgeons are unfamiliar with the techniques required for these procedures. The authors describe a step-by-step operative technique and provide several illustrations. Total sacrectomy is performed by sequential anterior and posterior approaches that involve a rectus abdominis pullthrough pedicle flap reconstruction. The anterior procedure is an intraperitoneal approach used to expose the anterior aspect of the tumor, to ligate the main tumor vessels, and to conduct an anterior partial sacrectomy. After this, the rectus abdominis myocutaneous flap, based on the inferior epigastric vessel, is prepared, and a posterior sacrectomy is performed, dividing all sacral nerve roots in the thecal sac. After complete en bloc extirpation of the sacrum with tumor, spinopelvic reconstruction and closure with a myocutaneous flap are performed. Spinopelvic reconstruction is undertaken using a modified Galveston technique or double iliac screw fixation combined with posterior lumbar segmental fixation. These provide a long lever arm within the ilium to counteract the forces exerted by the lumbar spine. Understanding the nature of the disease as well as the biomechanics of the lumbosacral pelvic area and spinopelvic fixation will help surgeons select the appropriate treatment for sacral tumors.

Synovial cyst in the cervical region causing severe myelopathy.

The authors describe a case of an 80-year-old man with a gradual weakness of the lower extremities not linked to any known traumatic episode over the 2 weeks before admission. CT scan and MRI of the spine revealed a cystic formation, measuring about 1 cm in diameter, at C7-T1 at the left posterolateral site at the level of the articular facet. During surgery, the mass appeared to be in the ligamentum flavum at the level of the articular facet and was in contact with the dura mater. After the removal of the mass, there was an immediate and significant improvement of the patient's symptoms. Histopathologic examination showed the cyst to be composed of nonspecific degenerative fibrous tissue with mild inflammatory change and confirmed the cyst as a synovial cyst. Synovial cyst in the cervical region is a very rare lesion causing myelopathy. Surgical removal of the cyst and decompression of the spinal cord results in good neurological recovery.

Box-shape cervical expansive laminoplasty: clinical and radiological outcomes.

OBJECTIVE: Box-shape cervical expansive laminoplasty is a procedure that utilizes a Miniplate® or Maxpacer® to achieve maximal canal expansion. This method is expected to show much larger canal expansion and good clinical outcome. So we investigated the clinical and radiological outcome of Box-shape cervical expansive laminoplasty. METHODS: Between June 2008 and July 2013, we performed cervical expansive laminoplasty in 87 and 48 patients using the Box-shape cervical expansive laminoplasty, respectively. We analyzed the clinical results of these operations using the Japanese Orthopedic Association (JOA) scoring system and by assessing the position of intralaminar screws with postoperative computed tomography (CT) at POD-6 months. RESULTS: A total of 48 patients with ossification of the posterior longitudinal ligament (OPLL) (36 pts), cervical spondylotic myelopathy (CSM) (12 pts) were enrolled. Overall JOA scores improved from 11.49 to 14.22 at POD-6 months (OPLL: 11.32 -->14.3; CSM: 12-->14). Postoperative CT scans were performed in 39 patients at 177 levels for a total of 354 screws. The malpositioning rate of intralaminar screws was 3.4% and hardware-related neurologic complications did not occur. CONCLUSION: Box-shape cervical expansive laminoplasty creates maximal spinal canal expansion and leads to improved cervical myelopathy. The use of intralaminar screws to fix the remodeled lamina-facet does not represent a significant difficulty.

Cervical expansive laminoplasty with 90° box-shape double door method.

OBJECTIVE: The aim of this study is to introduce the surgical method with miniplate and compared the expansion rate of the spinal canal area with other kinds of lamina spacers. METHODS: Between June. 2008 and May 2011, we performed expansive cervical laminoplasty on 61 patients. We analyzed the results of these operations, examining type of lamina spacer used, spinal canal areas between pre- and postoperative CT scans, and operative methods. RESULTS: 39 patients were analyzed retrospectively. Miniplates were used in 21 patients with 103 levels. Hydroxyapatite (HA) was used in 6 patients with 29 levels, and Centerpiece® was used in 12 patients with 54 levels. The expansion area was calculated using Photoshop CS3®. The expansion rate of the miniplates was 76.5%, that of HA was 49.8%, and that obtained with Centerpiece was 50.6%. The excellent 90° box-shaped widening of the laminae achieved through the surgery can be checked easily by AP X-ray. All miniplates are positioned horizontally and parallel, and the lamina is seen as a pedicle of thoracic or lumbar spine due to its 90° erect position. Neurologic improvement and clinical outcomes will be discussed. No complications were reported with miniplates. CONCLUSION: Box-shaped laminoplasty with miniplates is the widest spinal canal expansion method among the three types of implants examined.

Diagnosis of Cervical OPLL in Lateral Radiograph and MRI: Is it Reliable?

OBJECTIVE: Cervical OPLL is a relatively common cause of developing cervical myelopathy or radiculopathy in Asians. Cervical OPLL is sometimes missed in lateral radiography or MRI. In the present study, we analyzed the diagnostic accuracy of cervical OPLL in lateral radiography and MRI compared to CT scan. METHODS: This is a retrospective study of forty-six patients who underwent decompressive surgery anteriorly or posteriorly in our institute. All patients were diagnosed with cervical OPLL by CT scan. The patients were grouped into continuous type, segmental type, mixed type, and localized type. We then evaluated lateral radiographs and MRI compared to CT scans. The diagnostic accuracy and false negative rates in lateral radiograph and MRI were evaluated. RESULTS: In a total of 46 patients diagnosed with cervical OPLL in CT scans, diagnostic accuracy using lateral radiograph and MRI were 52.2%(24/46) and 58.7%(27/46), respectively. In the continuous type group, diagnostic accuracy using lateral radiograph and MRI were 85.7%(6/7) and 100.0%(7/7). In the segmental type group, diagnostic accuracy using lateral radiograph and MRI were 27.3%(6/22) and 31.8%(7/22). In the mixed type group, diagnostic accuracy was 91.7%(11/12) in lateral radiograph and 83.3%(10/12) in MRI. In the localized group, diagnostic accuracy was 20.0%(1/5) in lateral radiograph and 60.0%(3/5) in MRI. CONCLUSION: The diagnostic accuracy of cervical OPLL using lateral radiograph and MRI was less than using CT scan. For the best treatment plan, preoperative CT scan should be performed to detect conditions of ossifications such as cervical OPLL.

New technical tip for anterior cervical plating : make hole first and choose the proper plate size later.

OBJECTIVE: It is well known that plate-to-disc distance (PDD) is closely related to adjacent-level ossification following anterior cervical plate placement. The study was undertaken to compare the outcomes of two different anterior cervical plating methods for degenerative cervical condition. Specifically, the new method involves making holes for plate screws first with an air drill and then choosing a plate size. The other method was standard, that is, decide on the plate size first, locate the plate on the anterior vertebral body, and then drilling the screw holes. Our null hypothesis was that the new technical tip may increase PDD as compared with the standard anterior cervical plating procedure. METHODS: We retrospectively reviewed 49 patients who had a solid fusion after anterior cervical arthrodesis with a plate for the treatment of cervical disc degeneration. Twenty-three patients underwent the new anterior cervical plating technique (Group A) and 26 patients underwent the standard technique (Group B). PDD and ratios between PDD to anterior body heights (ABH) were measured using postoperative lateral radiographs. In addition, operating times and clinical results were reviewed in all cases. RESULTS: The mean durations of follow-up were 16.42±5.99 (Group A) and 19.83±6.71 (Group B) months, range 12 to 35 months. Of these parameters mentioned above, cephalad PDD (5.43 versus 3.46 mm, p=0.005) and cephalad PDD/ABH (0.36 versus 0.23, p=0.004) were significantly greater in the Group A, whereas operation time for two segment arthrodesis (141.9 versus 170.6 minutes, p=0.047) was significantly lower in the Group A. There were no significant difference between the two groups in caudal PDD (5.92 versus 5.06 mm), caudal PDD/ABH (0.37 versus 0.32) and clinical results. CONCLUSION: The new anterior cervical plating method represents an improvement over the standard method in terms of cephalad plate-to-disc distance and operating time.

Minimally invasive transforaminal lumbar interbody fusion using a single interbody cage and a tubular retraction system : technical tips, and perioperative, radiologic and clinical outcomes.

OBJECTIVE: A minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has recently been introduced. However, MIS TLIF is a technically challenging procedure. The authors performed retrospective analysis about MIS TLIF using a single interbody cage. METHODS: Twenty-eight consecutive patients were treated by MIS TLIF. Of these 28 patients, 20 patients were included in this retrospective study. Perioperative, clinical, and radiologic outcomes were assessed. Clinical outcomes were assessed using Oswestry Disability Index (ODI) and Visual Analogue Scores (VAS). Fusion rates and cross-sections of operated spinal canals were assessed by CT. RESULTS: Twelve patients underwent MIS TLIF at one segment and 8 patients at two segments (L3/4: 4, L4/5: 17, L5/S1: 7). Operation time for a single segment was 131.7 min and for two segment was 201.4 min, and corresponding blood losses were 208.3 mL and 481.2 mL, respectively. ODI and VAS scores were significantly improved at 6 months postop (ODI from 30.32 to 15. 54, VAS from 7.80 to 2.20, p = 0.001). Twenty-two segments (78.6%) achieved grade I fusion, 4 segments (14.3%) achieved grade II, 2 segments (7.1%) achieved grade III and 0 segments achieved grade IV at 12 months. Postoperatively at 12 months, spinal canal cross sectional areas at disc spaces significantly increased from 157.5 to 294.3 mm(2) (p = 0.012). CONCLUSION: MIS TLIF achieved good clinical outcomes and high fusion rates. Our findings show that MIS TLIF performed with a single interbody cage and a tubular retractor system can be used as a standard MIS TLIF technique.