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Objective: There is a lack of literature on indirect decompression in uniportal endoscopic posterolateral transforaminal lumbar interbody fusion (EPTLIF). Our aim is to evaluate the dimensions of the spinal canal and contralateral foramen before and after EPTLIF.Methods: This is a retrospective study of patients who underwent EPTLIF in a tertiary spine centre over a 2-year period. The cross-sectional area of the spinal canal and the contralateral foramen at the level of fusion were measured on magnetic resonance imaging scan at 1-day postoperation and at the final follow-up. Patients were grouped according to the decompression performed as per the clinician’s judgement.Results: One hundred fifty-two levels of fusion were performed in 120 patients. There was a statistically significant clinical improvement in visual analogue scale and Oswestry Disability Index scores postoperation. The measurements of the spinal canal area were 106.0 mm2, 138.8 mm2, and 195.5 mm2; while contralateral foraminal area were 73.2 mm2, 104.4 mm2, and 120.7 mm2 at preoperation, 1-day postoperation, and at the final follow-up, respectively (p < 0.001). For the subgroup analyses, spinal canal area measurements for the bilateral decompression cohort (n = 35) were 57.0 mm2, 123.9 mm2, and 191.8 mm2; for the ipsilateral decompression cohort (n = 42) were 89.3 mm2, 128.9 mm2, 183.3 mm2; and for the cohort without any decompression and only cage inserted (n = 75) were 138.3 mm2, 151.2 mm2, and 204.1 mm2 (p < 0.001). Contralateral foraminal area measurements were 73.3 mm2, 106.4 mm2 and 120.4 mm2 in the bilateral decompression cohort; 69.5 mm2, 99.0 mm2, 116.9 mm2 in the ipsilateral decompression cohort; and 75.1 mm2, 106.5 mm2, 122.9 mm2 in the cohort without any decompression (p < 0.001).Conclusion: Indirect decompression of both the spinal canal and the contralateral foramen can be achieved via EPTLIF. Decompression on an asymptomatic contralateral side is not necessary.

Study Design: Prospective radiographic comparative study.Purpose: To compare and understand the load-bearing properties of each functional spinal unit (FSU) using three commonly assumed, physiological, spinal postures, namely, the flexed (slump sitting), erect (standing) and extended (backward bending) postures. Overview of Literature: Sagittal spinal alignment is posture-dependent and influences the load-bearing properties of the spine. The routine placement of intervertebral cages “as anterior as possible” to correct deformity may compromise the load-bearing capabilities of the spine, leading to complications.Methods: We recruited young patients with nonspecific low back pain for

Background Controversies for treatment of acromioclavicular joint injuries in particular type III injuries may be partially attributed to the lack of a standardized method of radiography and measurement technique. Previous studies looking at the Rockwood classification showed poor inter- and intraobserver reliability (Kappa value approximately 0.20-0.50). We hypothesized that the use of unilateral instead of bilateral acromioclavicular joint radiographs was the cause of this finding. In this article, we standardized the methodology to perform the radiograph and to measure the coracoclavicular distances. We designed the study to focus on the reliability of differentiating type III and type V injuries. Methods A standardized radiographic protocol for bilateral Zanca view was established in our institution. All patients who underwent this radiographic examination over a 3-year period were reviewed. Radiographs of 55 patients with significant (type III or V) injury met the inclusion criteria. For the interobserver reliability, a retrospective radiographic review was performed by 6 orthopedic surgeons and graded as either type III or V. For intraobserver reliability, a similar process was repeated by 3 observers after a period of 6 weeks. Results Going by the majority agreement of the 6 reviewers, there were 34 type III injuries and 19 type V injuries. The Fleiss kappa for interobserver reliability was calculated to be 0.624. The Cohen kappa for intraobserver reliability was calculated to be 0.696. Discussion The use of a standardized radiographic protocol—taking bilateral Zanca views on the same radiographic plate—would help eliminate a significant amount of variability and improve the reliability of classifying acromioclavicular joint injuries using the Rockwood classification, which uses a relative measure to the contralateral site as its definition criteria. Other possible sources of poor reliability may include the masking of injuries by muscle spasm, resulting in a misdiagnosis of a high-grade injury as a lower-grade one and the possible need to subclassify type III injuries. Conclusion Reliability of the Rockwood classification can be improved through the use of a standardized radiographic protocol to improve the detection of vertical instability. Similar to Rockwood dividing up Tossy grade 3 injuries when he noted the differential outcome and intervention, Rockwood type III injuries would likely require further subclassification as it remains an anomalous tool with high variability. Further studies are required to understand the pathologic basis of transition of type III into type V injury.

Study design A cross-sectional study on a randomly selected prospective cohort of patients presenting to a single tertiary spine center. Objective The aim of this study was to describe the clinical and radiographic parameters of patients with S- and C-shaped thoracolumbar sagittal spinal profiles, and to identify predictors of these profiles in a natural, relaxed sitting posture. Summary of background data Sagittal realignment in adult spinal deformity surgery has to consider the sitting profile to minimize the risks of junctional failure. Persistence of an S-shaped sagittal profile in the natural, relaxed sitting posture may reflect a lesser need to accommodate for this posture during surgical realignment. Methods Consecutive patients with low back pain underwent whole body anteroposterior and lateral radiographs in both standing and sitting. Baseline clinical data of patients and radiographic parameters of both standing and sitting sagittal profiles were compared using χ, unpaired t tests, and Wilcoxon rank-sum test. Subsequently, using stepwise multivariate logistic regression analysis, predictors of S-shaped curves were identified while adjusting for confounders. Results Of the 120 patients included, 54.2% had S-shaped curves when sitting. The most common diagnoses were lumbar spondylosis (26.7%) and degenerative spondylolisthesis (26.7%). When comparing between patients with S- and C-shaped spines in the sitting posture, only diagnoses of degenerative spondylolisthesis (odds ratio [OR], 5.44; P = 0.01) and degenerative scoliosis (OR, 2.00; P = 0.039), and pelvic incidence (PI) >52.5° (OR, 5.48; P = 0.008), were predictive of an S-shaped sitting sagittal spinal alignment on multivariate analysis. Conclusion Stiffer lumbar curves (e.g., patients with degenerative spondylolisthesis and degenerative scoliosis) or those who have a predilection for an S-shaped standing sagittal profile when sitting (e.g., high PI) may be more amenable to fusion in accordance with previously studied sagittal realignment targets. In contrast, more flexible curves may benefit from less aggressive lordotic realignment to prevent potential junctional failures. Level of evidence 3.

To describe normal variations in sagittal spinal radiographic parameters over an interval period and establish physiological norms and guidelines for which these images should be interpreted. Data were prospectively collected from a continuous series of adult patients with first-episode mild low back pain presenting to a single institution. The sagittal parameters of two serial radiographic images taken 6-months apart were obtained with the EOS® slot scanner. Measured parameters include CL, TK, TL, LL, PI, PT, SS, and end and apical vertebrae. Chi-squared test and Wilcoxon Signed Rank test were used to compare categorical and continuous variables, respectively. Sixty patients with a total of 120 whole-body sagittal X-rays were analysed. Mean age was 52.1 years (SD 21.2). Mean interval between the first and second X-rays was 126.2 days (SD 47.2). Small variations (

MINI: Pressure injuries are prevalent in patients undergoing spine surgery while prone. Multiple risk factors exist and should be addressed. We found that patients undergoing spinal deformity correction surgery are at unique risk (odds ratio 3.31, P = 0.010) due to body morphological changes occurring secondary to intraoperative changes in spinal alignment. Study design Review of data and prospective study. Objective To investigate the prevalence and predictive factors of pressure injuries in spine surgery performed in the prone position, and to determine whether morphological changes and truncal shifts occurring during deformity correction predispose to this complication. Summary of background data Spine surgery performed in the prone position presents the risk of developing pressure injuries. This risk is potentially increased in deformity correction, because it tends to involve more extensive procedures, with associated longer operating times. Methods Cases of pressure injuries after spine surgery in the prone position were reviewed to ascertain prevalence and determine risk factors. Data including patient factors (age, sex, height, weight, body mass index, American Society of Anesthesiologists grade, comorbidities, Braden scale, neurological status, spinal pathology) and surgical factors (approach, procedure type, number of screws, operated levels, operative time) were collected. Independent risk factors were identified via multivariate analysis. A subsequent prospective analysis of all patients undergoing spinal deformity correction was conducted by performing intraoperative measurements of body morphological changes and shifts in truncal positions. Statistical correlation was performed to determine whether positional shifts cause pressure injuries. Results The prevalence of pressure injuries was 23.0%. Previous skin problems (P = 0.034), myelopathy (P = 0.013), operative time >300 minutes (P = 0.005), and more than four operated levels (P = 0.006) were independent predictors of pressure injuries. Being a spinal deformity patient was also an independent risk factor for developing pressure injuries (odds ratio 3.31, P = 0.010). Significant changes in body measurements during deformity correction were predictive of pressure injuries. Conclusion Pressure injuries are prevalent in patients undergoing spine surgery while prone. Future studies should investigate strategies to prevent this complication based on the multiple risk factors identified in the present study. Patients undergoing spinal deformity correction surgery are particularly at risk due to intraoperative body morphological changes. Improved padding methods should be trialed in future studies. Level of evidence 3.

Evidence guiding the use of CT and MRI scans in blunt trauma patients who are obtunded remains controversial. This study aims to determine and predict if computed tomography (CT) scans alone can be performed without risking oversight of substantial injuries found on follow-up magnetic resonance imaging (MRI). This is a retrospective cohort study of 63 blunt trauma patients with a Glasgow Coma Scale of

Flexion radiographs have been used to identify cases of spinal instability. However, current methods are not standardized and are not sufficiently sensitive or specific to identify instability.This study aimed to introduce a new slump sitting method for performing lumbar spine flexion radiographs and comparison of the angular range of motions (ROMs) and displacements between the conventional method and this new method.This study used is a prospective study on radiological evaluation of the lumbar spine flexion ROMs and displacements using dynamic radiographs.Sixty patients were recruited from a single spine tertiary center.Angular and displacement measurements of lumbar spine flexion were carried out.Participants were randomly allocated into two groups: those who did the new method first, followed by the conventional method versus those who did the conventional method first, followed by the new method. A comparison of the angular and displacement measurements of lumbar spine flexion between the conventional method and the new method was performed and tested for superiority and non-inferiority.The measurements of global lumbar angular ROM were, on average, 17.3° larger (p.0001) using the new slump sitting method compared with the conventional method. They were most significant at the levels of L3-L4, L4-L5, and L5-S1 (p.0001, p.0001 and p=.001, respectively). There was no significant difference between both methods when measuring lumbar displacements (p=.814).The new method of slump sitting dynamic radiograph was shown to be superior to the conventional method in measuring the angular ROM and non-inferior to the conventional method in the measurement of displacement.

Sitting spinal alignment is increasingly recognized as a factor influencing strategy for deformity correction. Considering that most individuals sit for longer hours in a "slumped" rather than in an erect posture, greater understanding of the natural sitting posture is warranted.This study aimed to investigate the differences in sagittal spinal alignment between two common sitting postures: a natural, patient-preferred posture; and an erect, investigator-controlled posture that is commonly used in alignment studies.This is a randomized, prospective study of 28 young, healthy patients seen in a tertiary hospital over a 6-month period.Twenty-eight patients (24 men, 4 women), with a mean age of 24 years (range 19-38), were recruited for this study. All patients with first episode of lower back pain of less than 3 months' duration were included. The exclusion criteria consisted of previous spinal surgery, radicular symptoms, red flag symptoms, previous spinal trauma, obvious spinal deformity on forward bending test, significant personal or family history of malignancy, and current pregnancy.Radiographic measurements included sagittal vertical axis (SVA), lumbar lordosis (LL), thoracolumbar angle (TL), thoracic kyphosis (TK), and cervical lordosis (CL). Standard spinopelvic parameters (pelvic incidence, pelvic tilt [PT], and sacral slope) and sagittal apex and end vertebrae were also measured.Basic patient demographics (age, gender, ethnicity) were recorded. Lateral sitting whole spine radiographs were obtained using a slot scanner in the imposed erect and the natural sitting posture. Statistical analyses of the radiographical parameters were performed comparing the two sitting postures using chi-squared tests for categorical variables and paired t tests for continuous variables.There was forward SVA shift between the two sitting postures by a mean of 2.9 cm (p.001). There was a significant increase in CL by a mean of 11.62° (p.001), and TL kyphosis by a mean of 11.48° (p.001), as well as a loss of LL by a mean of 21.26° (p.001). The mean PT increased by 17.68° (p.001). The entire thoracic and lumbar spine has the tendency to form a single C-shaped curve with the apex moving to L1 (p=.002) vertebra in the majority of patients.In a natural sitting posture, the lumbar spine becomes kyphotic and contributes to a single C-shaped sagittal profile comprising the thoracic and the lumbar spine. This is associated with an increase in CL and PT, as well as a constant SVA. These findings lend insight into the body's natural way of energy conservation using the posterior ligamentous tension band while achieving sitting spinal sagittal balance. It also provides information on one of the possible causes of proximal junctional kyphosis or proximal junctional failure.

Background: A comparative survey from patients and radiographers of the new slump sitting flexion posture and the conventional standing forward bending posture. This study was performed to compare the technical and logistical aspects of the slump sitting versus the forward bending posture. Slump sitting flexes the lumbar spine more than the forward bending and increases the diagnosis rate of sagittal spinal instability up to 40% depending on the diagnostic criteria used. This should not come at the expense of patient safety and comfort nor burden the radiographers. Methods: Sixty patients were recruited from a single tertiary spine centre. Patients were block randomised into two groups with either the forward bending or the slump sitting being performed first. Feedback was obtained through self-administered questionnaires from patients regarding perceived safety, convenience and comfort, plus from radiographers regarding the imaging process, proxy measures of radiographer ability and scan difficulty. Results: There was no significant difference between the baseline characteristics in both groups. Majority (63%) of patients preferred slump sitting and felt that forward bending caused pain (P=0.025). Overall, slump sitting was equivalent in comfort, perceived safety and ease to forward bending. Despite requiring more logistics (P=0.031), more effort to set up (P=0.002) and explain (P=0.012), the majority of radiographers (83%) preferred slump sitting. This method was felt to be less dangerous (P=0.015) and easier to maintain (P Conclusions: This study showed that the superiority of slump sitting in allowing more lumbar flexion compared to the forward bending comes with patient safety or comfort. The technical demands of the learning curve can be offset with training. As such, slump sitting flexion views should be adopted as the standardized method for assessing spinal instability.

Study Design: A single-center, retrospective cohort study. Objective: To predict patient-reported outcomes (PROs) using preoperative health-related quality-of-life (HRQoL) scores by quantifying the correlation between them, so as to aid selection of surgical candidates and preoperative counselling. Methods: All patients who underwent single-level elective lumbar spine surgery over a 2-year period were divided into 3 diagnosis groups: spondylolisthesis, spinal stenosis, and disc herniation. Patient characteristics and health scores (Oswestry Low Back Pain and Disability Index [ODI], EQ-5D, and Short Form-36 version 2 [SF-36v2]) were collected at 6 and 24 months and compared between the 3 diagnosis groups. Multivariate modelling was performed to investigate the predictive value of each parameter, particularly preoperative ODI and EQ-5D, on postoperative ODI and EQ-5D scores for all the patients. Results: ODI and EQ-5D at 6 and 24 months improved significantly for all patients, especially in the disc herniation group, compared to the baseline. The magnitude of improvement in ODI and EQ-5D was predictable using preoperative ODI, EQ-5D, and SF-36v2 Mental Component Score. At 6 months, 1-point baseline ODI predicts for 0.7-point increase in changed ODI, and a 0.01-point increase in baseline EQ-5D predicts for 0.01-point decrease in changed EQ-5D score. At 24 months, 1-point baseline ODI predicts for 1-point increase in changed ODI, and a 0.01-point increase in baseline EQ-5D predicts for 0.009-point decrease in changed EQ-5D. A younger age is shown to be a positive predictor of ODI at 24 months. Conclusions: Poorer baseline health scores predict greater improvement in postoperative PROs at 6 and 24 months after the surgery. HRQoL scores can be used to decide on surgery and in preoperative counselling.

Comparative study of prospectively collected radiographic data.To predict physiological alignment of the cervical spine and study its morphology in different postures.There is increasing evidence that normal cervical spinal alignment may vary from lordosis to neutral to kyphosis, or form S-shaped or reverse S-shaped curves.Standing, erect sitting, and natural sitting whole-spine radiographs were obtained from 26 consecutive patients without cervical spine pathology. Sagittal vertical axis (SVA), global cervical lordosis, lower cervical alignment C4-T1, C0-C2 angle, T1 slope, C0-C7 SVA and C2-7SVA, SVA, thoracic kyphosis, thoracolumbar junctional angle, lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence were measured. Statistical analysis was performed to elucidate differences in cervical alignment for all postures. Predictive values of T1 slope and SVA for cervical kyphosis were evaluated.Most patients (73.0%) do not have lordotic cervical alignment (C2-C7) upon standing (mean -0.6, standard deviation 11.1°). Lordosis increases significantly when transitioning from standing to erect sitting, as well as from erect to natural sitting (mean -17.2, standard deviation 12.1°). Transition from standing to natural sitting also produces concomitant increases in SVA (-8.8-65.2 mm) and T1-slope (17.4°-30.2°). T1 slope and SVA measured during standing significantly predicts angular cervical spine alignment in the same position. SVA 10 mm significantly predicts C4-C7 kyphosis (P 0.001), and to a lesser extent, C2-C7 kyphosis (P = 0.02). T1 slope20° is both predictive of C2-C7 and C4-7 kyphosis (P = 0.001 and P = 0.023, respectively). For global cervical Cobb angle, T1 slope seems to be a more significant predictor of kyphosis than SVA (odds ratio 17.33, P = 0.001 vs odds ratio 11.67, P = 0.02, respectively).The cervical spine has variable normal morphology. Key determinants of its alignment include SVA and T1 slope. Lordotic correction of the cervical spine is not always physiological and thus correction targets should be individualized.3.

Adult spinal deformity correction sometimes involves long posterior pedicle screw constructs extending from the lumbosacral spine to the thoracic vertebra. As fusion obliterates motion and places supraphysiological stress on adjacent spinal segments, it is crucial to ascertain the ideal upper instrumented vertebra (UIV) to minimize risk of proximal junctional failure (PJF). The T10 vertebra is often chosen to allow bridging of the thoracolumbar junction into the immobile thoracic vertebrae on the basis that it is the lowest immobile thoracic vertebra strut by the rib cage.This study aimed to characterize the range of motion (ROM) of each vertebral segment from T7 to S1 to determine if T10 is truly the lowest immobile thoracic vertebra.This is a prospective, comparative study.Seventy-nine adults (mean age of 45.4 years) presenting with low back pain or lower limb radiculopathy or both, without previous spinal intervention, metastases, fractures, infection, or congenital deformities of the spine, were included in the study.A ROM5° across two vertebral segments as determined by the Cobb method from radiographs.Lumbar flexion-extension and neutral erect radiographs were obtained in randomized order using a slot scanner. Segmental ROM was measured from T7-T8 to L5-S1 and analyzed for significant differences using t tests. Age, gender, radiographical indices such as standard spinopelvic parameters, sagittal vertical axis (SVA), C7-T12 SVA, T1 slope, thoracic kyphosis (TK), and lumbar lordosis (LL) were studied via multivariate analysis to identify predictive factors for5° change in ROM at the various segmental levels. There were no sources of funding and no conflicts of interest associated with this study.In the thoracolumbar spine, significant decreases in ROM when compared with the adjacent caudad segment occurs up to T9-T10, with mean total ROM of 1.98±1.47° (p.001) seen in T9-T10, 2.19±1.67° (p.001) in T10-T11, and 3.92±3.21°(p.001) in T11-T12. The total ROM of T8-T9 (2.53±1.79°) was not significantly different from that of T9-T10 (p=.261). At the thoracolumbar junction, absence of scoliosis (OR 11.37, p=.020), high pelvic incidence (OR 1.14, p=.046), and low T1 slope (OR 1.45, p=.030) were predictive of ROM5°.Lumbar spine flexion-extension ROM decreases as it approaches the thoracolumbar junction. T10 is indeed the lowest immobile thoracic vertebra strut by the rib cage, and the last significant decrease in ROM is observed at T9-T10, in relation to T10-T11. However, because this also implies that a UIV of T10 would mean there is only one level of fixation above the relatively mobile segment, while respecting other factors that influence UIV selection, we propose the T9 vertebra as a more ideal UIV to fulfill the biomechanical concept of bridge fixation. However, this decision should still be taken on a case-by-case basis.

Introduction Autologous bone grafting has been accepted as the gold standard in the treatment of non-unions and in definitive filling of segmental bone defects. However, there have been well-recognised complications associated with their harvest. The Reamer Irrigator Aspirator (RIA) system is an alternative technique of autologous bone graft harvesting. Studies have been published in the Western population showing the efficacy and outcome of this technique. No prior studies were done in the Asian population, who has smaller average canals, different femoral geometry as compared to Caucasians and weaker bone density in both genders. We aim to present the findings and discuss its suitability in the Asian population when dealing with segmental bone loss and non-unions requiring reconstruction. Methods We conducted a retrospective analysis of all trauma patients with segmental bone loss and non-unions treated with RIA bone grafting over a 4.5 year period. A total of 57 cases of RIA bone grafting were conducted on 53 patients. The amount of bone graft harvested, blood loss and post-operative pain were measured. Patients were followed up for union rate as well as complications of the procedure. Results Union was achieved in 86.8% of patients. The mean time to union was 17.64 weeks. Seven patients did not achieve union after the first RIA surgery, in which six of seven were open fractures initially and six were smokers. One major intra-operative complication was recorded, that being a fractured femoral shaft due to thinning of the cortex by the RIA harvester. There were two patients who developed donor site superficial soft tissue infection that resolved after a course of antibiotics. There were no long-term complications seen in all patients. Conclusions The safety and efficacy of RIA bone graft harvesting for the management of non-union in the Asian population is promising, with adequate graft quantities, high success and low complication rates that are comparable to the Caucasian population. The diameter of the medullary canal in our population is suitable for this procedure. We believe that RIA bone graft harvesting provides a reliable and safe alternative source of autologous bone grafts for bone grafting of non-union sites.