"Various factors affecting the success of the ETV procedure in infants"-an insight via a prospective study.

BACKGROUND: Congenital hydrocephalus in infants treated with ETV has variable results in literature. We studied some supposed clinicoradiological parameters which though are considered vital in deciding operative management and have never been thoroughly studied to establish a well-defined association. AIM AND OBJECTIVE: To evaluate the influence of clinicoradiological profile and intraoperative findings over the outcome of ETV done in infants for congenital hydrocephalus. MATERIALS AND METHODS: All infants who underwent ETV in King George's Medical University, Lucknow, from January 2019 to February 2020 for congenital hydrocephalus were included. Their clinical, radiological, operative data was gathered. Infants were followed at 1, 3, and 6 months after ETV. ETV success was defined as stabilization of abnormal head growth with resolution of symptoms of raised ICP and no requirement of shunt surgery 6 months post-ETV. All the clinicoradiological and intraoperative factors were statistically correlated with the final outcome. RESULTS: Forty infants were operated for congenital hydrocephalus during the study period in our institution. Failure rate was higher in children younger than 3 months (p value of 0.04). Increase in head size was present in all 40 cases and bulging anterior fontanelle in 95% cases. Success rate of ETV at 1, 3, and 6 months was 62.5%, 40%, and 35%. Most of failure occurred within 3 months after the procedure. Expiry rate at 1, 3, and 6 month was 15%, 17.5%, and 17.5%. None of the intraoperative findings significantly correlated with the final outcome. CONCLUSION: ETV can be a luring treatment of congenital hydrocephalus in infants but has limited success rate because of the dependency of procedure on well-formed arachnoid villi for absorption. It also carries minimal risk of fatal complications like CSF leak and meningitis associated with it. Age is the only factor which truly reflects the outcome of the procedure.

Does Instrumentation of the Fractured Level in Thoracolumbar Fixation Affect the Functional and Radiological Outcome?

STUDY DESIGN: Retrospective comparative study. OBJECTIVES: To compare radiological and functional outcomes of patients with fixation constructs utilizing pedicle screw stabilization at the fracture level (FL group) versus patients with non-fracture level (NFL group) fixation in single level fractures of the thoracolumbar junction (T11-L1). METHODS: 53 patients of whom fracture level screw was used in 34 (FL group) were compared to 19 patients in NFL group. Radiological parameters analyzed were sagittal index, bi-segmental kyphosis (Cobb) angle and degree of vertebral height restoration. Prospectively collected patient reported functional outcomes and post-operative complications were also studied. Stepwise regression analysis adjusted by age, gender and functional scores was performed to account for the small numbers and unequal sizes of the groups. RESULTS: Back pain score was significantly lower in the FL group (P < 0.025). Core Outcome Measures Index scores and leg pain scores, though low in the FL group, were not statistically significant. The regression analysis showed that the inclusion of the fracture-level screw was independently associated with a greater change in sagittal index and vertebral height restoration post-operatively. Sagittal index was maintained through to final follow up as well. The bi-segmental Cobb's angle correction was not associated with fracture-level screw construct. There was no significant difference between the groups for revision surgery, deep infection, implant failure or length of hospital stay. CONCLUSION: The inclusion of the fracture-level pedicle screws in the fixation construct significantly improves the immediate and final measured radiological parameters, with improved functional scores in single level unstable vertebral fractures of the thoracolumbar junction.

Pediatric Cervical Spine Injuries.

Objective Pediatric cervical spine injuries are rare and account for 1 to 2% of all pediatric spine injuries. There is a paucity of data on pediatric cervical spine injuries in developing countries like India. The purpose of this study is to review and analyze our 5 years of experience with pediatric cervical spine injuries. Methods All the available medical records over the 5 years were reviewed retrospectively. The data was analyzed to know the epidemiology, mechanism of injury, injury patterns, management, and outcome. The patients were divided into two groups: 0 to 9 years and 10 to 18 years. Results Seventy-five eligible records were included in our study. The incidence of cervical spine injuries was significantly lower in younger children than the older ones ( p < 0.042). The most common mechanism of injury was fall from height: 33 (44%) patients followed by road traffic accidents: 27 (36%) patients. The involvement of the upper cervical spine was significantly higher in younger children ( p < 0.001). Fractures with subluxation were the most common pattern of injury, observed in 35 (47%) patients. However, fractures with subluxation were uncommon in younger children compared with older children ( p < 0.04). Spinal cord injury without radiographic abnormality (SCIWORA) was observed in 42% of younger children compared with 8% of older children ( p < 0.02). Thirty (40%) patients were managed surgically; anterior cervical corpectomy with fusion was the most commonly performed procedure in 19 (63%) patients. The overall mortality was 20%. Conclusion The results of our study revealed predominant involvement of the upper cervical spine in children younger than 10 years of age. SCIWORA was documented in both the age groups with a significantly higher incidence in younger children. The instrumentation and fusion techniques in children are safe; however, developing pediatric spine needs special considerations.

The Role of Early Postoperative Intracranial Pressure Monitoring in Predicting the Outcome of Endoscopic Third Ventriculostomy Performed in Infants With Congenital Hydrocephalus: A Prospective Analysis.

Introduction Hydrocephalus is an excessive accumulation of cerebrospinal fluid (CSF) in the cavity and spaces of the brain. To date, there is no single method to accurately assess the compliance of subarachnoid spaces after endoscopic third ventriculostomy (ETV). Objective To analyze the intracranial pressure (ICP) trends in the early postoperative period in infants undergoing ETV for congenital hydrocephalus and correlate them with the final outcome. Material and methods This is a single-center prospective study conducted at the Department of Neurosurgery of our institute from January 2019 to February 2020. Infants presented with congenital hydrocephalus mandating ETV were included in the study. ICP was continuously monitored for the first three days after the procedure. ICP values were recorded hourly, and 24 ICP values obtained daily were averaged to obtain a daily average value (DAV). Results Forty patients were recruited in the study. The mean age of the study population was 4.7 ± 2.8 months; 80% of the infants were <6 months of age. The male/female ratio was 5.7:1. The most common etiology was congenital aqueductal stenosis, which was observed in 18 (45%) of the patients, followed by Dandy-Walker malformation (DWM) in 11 (27.5%) of the patients. On considering a difference of >1 mmHg between the first and third postoperative day, the ETV success rate was dropped from 50% in stable trend to 11% in progressive increase trend, which was statistically significant (p = 0.044). At DAV variation of >2 mmHg in progressive increase trend, the sensitivity of stable ICP trend increased to 100% in predicting ETV success. Also, the negative predictive value (the ability of a stable trend to rule out ETV failure) reached 100%. The overall success rates of ETV in our study at one, three, and six months were 62.5%, 40%, and 35%, respectively. Conclusion A progressive increase in the ICP trend (with a difference of >2 mmHg between postoperative days 1 and 3) was the best predictor of ETV failure in our study. It was superior to any other clinical or radiological variable in our study, which was affecting the outcome.

Revision pedicle screws with impaction bone grafting: a case series.

BACKGROUND: Pedicle screw fixation in spinal constructs can be subject to failure requiring revision surgery. In cases of aseptic loosening various salvage techniques have been described. Revision screws augmented with cement have become popular but are not without risks. Larger diameter screws are often used but result in reducing bone stock or expanding the pedicles. We present a novel technique of pedicle screw revision by impaction bone allografting and a case series. METHODS: The failed screws are removed. The screw track is probed to check its integrity. Milled bone allograft is funneled into the screw hole and sequentially impacted, before insertion of a replacement screw. We report a case series and describe a single case where this method has been used. Information was gathered from the electronic patient record in our hospital. RESULTS: Ten screws were revised in 7 patients. Mean age at first surgery was 60.86 (48-76) years. Average time between first surgery and revision was 12.6 (4.7-49.9) months. Average follow-up was 26.2 (5.7-62.2) months and no screws showed any signs of loosening. CONCLUSIONS: Impaction grafting with bone allograft is a technique for pedicle screw salvage that can be used safely and effectively as an alternative to cemented screws, when pedicle screws have failed by aseptic loosening. It avoids the risks associated with cemented screws and in our series was successful.

Colloid cysts: Neuropsychological outcome, quality of life and long-term control after endoscopic gross total resection.

BACKGROUND: Endoscopy is increasingly being adopted for removing colloid cysts. However, the neuropsychological outcome and quality of life (QOL) have not been studied in detail. This study is to evaluate the efficacy of endoscopic excision on cognitive measures and QOL. METHODS: Patients with colloid cysts larger than 7 mm, undergoing endoscopy were prospectively studied concerning clinico-radiology, cognitive parameters (age and education adjusted), extent of resection and recurrence. A cross-sectional QOL assessment was additionally performed on endoscopic patients in comparison with cases who underwent microsurgery or standalone ventriculo-peritoneal (VP) shunt. RESULTS: A total of 22 endoscopic patients with a mean age of 34 years and a mean cyst diameter of 19 mm were studied. Gross total resection(GTR) could be achieved in all. Over a mean follow-up of 53.4 months, none had a recurrence, ventriculomegaly, or retreatment. Among neuropsychological parameters, digit span was the most affected before surgery. There was a broad-based improvement in the mean global cognitive score from 40.63(±10.4) at baseline to 50.25(±5.8) after endoscopy with maximum improvement in 'immediate recall.' The change in scores also had a significant inverse correlation with cyst size, with cysts larger than 18 mm, resulting in lower scores following endoscopy(R=-0.9, P=0.01). QOL was significantly influenced by visual and cognitive impairments and was better among endoscopic patients than similar microsurgery or VP shunt controls, with a significant difference in social and environmental domains(P=0.02). CONCLUSION: Endoscopy is effective in achieving GTR and long-term control, with neuropsychological improvement correlated with cyst size. This is probably the first report to show QOL is influenced by cognitive parameters and is better following endoscopy than after microsurgery or VP shunt.

Spatiotemporal contact density explains the disparity of COVID-19 spread in urban neighborhoods.

The rapid early spread of COVID-19 in the US was experienced very differently by different socioeconomic groups and business industries. In this study, we study aggregate mobility patterns of New York City and Chicago to identify the relationship between the amount of interpersonal contact between people in urban neighborhoods and the disparity in the growth of positive cases among these groups. We introduce an aggregate spatiotemporal contact density index (CDI) to measure the strength of this interpersonal contact using mobility data collected from mobile phones, and combine it with social distancing metrics to show its effect on positive case growth. With the help of structural equations modeling, we find that the effect of CDI on case growth was consistently positive and that it remained consistently higher in lower-income neighborhoods, suggesting a causal path of income on case growth via CDI. Using the CDI, schools and restaurants are identified as high contact density industries, and the estimation suggests that implementing specific mobility restrictions on these point-of-interest categories is most effective. This analysis can be useful in providing insights for government officials targeting specific population groups and businesses to reduce infection spread as reopening efforts continue to expand across the nation.

Spinal surgery during the COVID-19 pandemic: the experience in a tertiary referral centre.

BACKGROUND: The COVID-19 pandemic first came to prominence in December 2019, and since then has swept the globe, causing one of the largest public health problems seen. It has had a wide-ranging impact on healthcare provision, with a cessation of elective operating. We aimed to assess the impact of COVID-19 on a tertiary referral centre for spinal surgery in England. METHODS: An 82-day study period from 20th March 2020 to 10th June 2020 was used, and all spinal surgical patients were followed up prospectively, comparing patients from the same date range in 2019. We assessed rate of COVID transmission, 30-day mortality rates, complication rates and length of hospital stay in a large tertiary Teaching hospital in England. RESULTS: Seventy-eight patients were operated on during the COVID-19 pandemic period, with a 30-day mortality rate of 4.2%. Two of these deaths were attributable to COVID-19 (2.56%). The mean length of stay was 10.8 days. Neither the 30-day mortality rate or the length of stay was statistically significant compared to the 2019 control period. Five patients (6.4%) tested positive for COVID-19, all were negative at time of surgical intervention. Our complication rate was 10.3% during the COVID-19 pandemic period. CONCLUSIONS: The number of operative cases performed during the COVID-19 pandemic fell by one-third compared to the same period in 2019. The COVID-19 pandemic did not cause a significant increase in 30-day mortality rate, length of stay, or complication rates. Further studies with larger patient numbers and longer-term outcomes will be needed to fully assess the impact of the COVID-19 pandemic on spinal surgery.

Complications Encountered with ETV in Infants with Congenital Hydrocephalus.

BACKGROUND: Hydrocephalus is an abnormal excessive accumulation of cerebrospinal fluid (CSF) in the cavity and spaces of the brain. Endoscopic third ventriculostomy (ETV) has been an established treatment modality for congenital hydrocephalus. However, in very young infants, the results are challenging. In our study, we have evaluated whether ETV really offers an acceptable complication-free postoperative course. OBJECTIVE: To study the complication and mortality rate in infants having congenital hydrocephalus treated with ETV. MATERIALS AND METHODS: This is a single-center prospective study conducted at the Department of Neurosurgery, K. G. M. U, Lucknow, from January 2019 to February 2020. We studied 40 infants presenting with clinical and radiological features suggestive of congenital hydrocephalus. Follow-up was done at the first, third, and sixth months after discharge. RESULTS: Nineteen infants (47.5%) required a second CSF diversion procedure at 6 months of follow-up. The failure rate was significantly higher in infants less than 3 months of age (P value of 0.04). The ETV site bulge was the most frequent complication encountered in the postoperative period, occurring in 20% of the cases. Eventually, all these infants required a ventriculoperitoneal shunt; 15% developed clinical features consistent with the diagnosis of post-ETV meningitis. The ETV site CSF leak occurred in 10% of the patients. Subdural hygroma developed in 7.5% of the patients; 17.5% of the patients contributed to mortality with a mean time of expiry of 22 days post-procedure. All these deaths had multifactorial causes and could not be said as a complication or failure of ETV. CONCLUSION: We do not recommend ETV for infants less than 3 months because of a high failure rate. The ETV site bulge was the most reliable and earliest marker of failure and a second CSF diversion surgery should be immediately considered.

Concomitant back and leg pain as predictors for trajectories of poor outcome after single level lumbar micro-decompression alone and with micro-discectomy: a study of 3,308 patients.

BACKGROUND: Lumbar decompression is the commonest spinal intervention. One in four patients have suboptimal outcome postoperatively, however no large studies identified clear poor outcome predictors. The aim of this study was to study low back pain (LBP) as a predictor of poor outcome following lumbar micro-decompression. METHODS: Prospectively collected spinal registry data was analysed for patients who underwent primary, single-level, decompression with or without discectomy at single spinal centre (2011-2017). Based on the response to the Likert global outcome question, we had two outcome groups (good & poor). Percentage of achievement of minimum clinically relevant change (MCRC) for Core Outcome Measures Index (COMI) score, LBP and leg pain (LP) was examined. A two-step approach was adopted. First, COMI score, LBP and LP visual analogue scales (VAS) trajectories were modelled using a discrete mixture model. Second, multinomial logistic regression was used to determine the association between variables and trajectories. RESULTS: We included 3,308 patients with mean follow up (1.4 y). MCRC was achieved in COMI score in 63% of cases, 42% in LBP and 62% in LP. A three-group trajectory model was identified: large-improvement (LI) (n=980), moderate-improvement (MI) (n=1,364) and no-improvement (NI) (n=966) with 99.5%, 84.5% and 31.5% of patients presenting good outcome, respectively. Higher pre-operative LBP and COMI score and smoking were strongly associated with MI and NI. In addition, higher LP, post-operative surgical complications, previous surgery at same level, conservative treatment >6 months and anxiety/depression were associated with NI. CONCLUSIONS: This is the first large-scale study reporting preoperative LBP severity, spinal stenosis and smoking as predictors for poor functional outcomes post lumbar decompression with or without discectomy. This is very useful while counselling patients for surgery to meet realistic expectations.

Medium-term outcome of posterior surgery in the treatment of non-tuberculous bacterial spinal infection.

OBJECTIVE: to evaluate the outcome of posterior spinal stabilization surgery for the management of bacterial spinal infection. METHODS: 21 patients with bacterial infection were managed surgically with posterior stabilization. Outcome measures included neurological status. Follow-up data collected using Spine Tango COMI questionnaires and Euro Qol EQ-5D. RESULTS: The mean improvement in neurological deficits was 0.91 Frankel grade. Residual symptoms of pain had no or minor effect on the work or usual activities in 52% of subjects, with 88% reported having either no or mid problems with mobility. CONCLUSION: Posterior surgery can improve neurological outcome in approximately half of the patients.

Comparative study of multilevel posterior interbody fusion plus anterior longitudinal ligament release versus classic multilevel posterior interbody fusion in the treatment of adult spinal deformities.

OBJECTIVE: Sagittal imbalance and loss of lumbar lordosis are the main drivers of functional disability in adult degenerative scoliosis. The main limitations of the classic posterior lumbar interbody fusion technique are increased risk of neurological injury and suboptimal correction of the segmental lordosis. Here, the authors describe the radiological results of a modified posterior lumbar interbody fusion and compare the results with a historical cohort of patients. METHODS: Eighty-two consecutive patients underwent surgical treatment for degenerative scoliosis/kyphosis in a single tertiary referral center for complex spinal surgery. Fifty-five patients were treated using the classic multilevel posterior lumbar interbody fusion (MPLIF) technique and 27 were treated using the modified MPLIF technique to include a release of the anterior longitudinal ligament (ALL) and the annulus. A radiographic review of both series of patients was performed by two independent observers. Functional outcomes were obtained, and patients were registered in the European Spine Tango registry. RESULTS: The mean L4-5 disc angle increased by 3.14° in the classic MPLIF group and by 12.83° in MPLIF plus ALL and annulus release group. The mean lumbar lordosis increased by 15.23° in the first group and by 25.17° in the second group. The L4-S1 lordosis increased on average by 4.92° in the classic MPLIF group and increased by a mean of 23.7° in the MPLIF plus ALL release group when both L4-5 and L5-S1 segments were addressed. There were significant improvements in the Core Outcome Measures Index and EQ-5D score in both groups (p < 0.001). There were no vascular or neurological injuries observed in either group. CONCLUSIONS: The authors' preliminary results suggest that more correction can be achieved at the disc level using posterior-based ALL and annulus release in conjunction with posterior lumbar interbody fusion. They demonstrate that ALL and annulus release can be performed safely using a posterior-only approach with minimal risk of vascular injury. However, the authors recommend that this approach should only be used by surgeons with considerable experience in anterior and posterior spinal surgery.

The implementation of enhanced recovery after surgery (ERAS) in complex spinal surgery.

BACKGROUND: This paper aims to review the introduction of an enhanced recovery after surgery (ERAS) service within complex spinal surgery, with an aim to assess if this is a cost effective way to improve the overall experience of such complex surgery. METHODS: The ERAS model was defined and followed within a regional centre for complex spinal surgery in the UK. Outcomes such as length of stay (LOS) and satisfaction were measured before and after implementation of the service. RESULTS: LOS was reduced and both patient and staff satisfaction improved following the implementation of the ERAS service. CONCLUSIONS: The ERAS model can successfully be implemented within complex spinal surgery, to help improve satisfaction and reduce cost.

The clinical and radiological outcomes of multilevel posterior lumbar interbody fusion in the treatment of degenerative scoliosis: a consecutive case series with minimum 2 years follow up.

BACKGROUND: Surgical treatment for adult degenerative scoliosis (ADS) is a complex undertaking and is associated with a high complication rate. Our aim was to evaluate the clinical and radiological outcomes, mortality and morbidity of multilevel posterior lumbar interbody fusion (MPLIF) in the treatment in ADS based on the experience of a single tertiary referral center for spinal surgery. METHODS: We performed a retrospective analysis of prospectively collected data of consecutive patients who had undergone multi-level posterior interbody fusion for degenerative scoliosis. We prospectively recorded patients' demographics, co-morbidities; coronal and sagittal plane deformity assessment and surgical details: number of instrumented levels, and intra-operative and postoperative complications. Functional outcomes and patient-reported complications were entered in our local spine surgery database (part of the Eurospine Spine Tango Registry) and used to collect data on functional scores and patient-reported complications preoperatively and at 6, 12 and 24 months' follow-up. RESULTS: Our study involved 13 males and 51 females with a mean age of 70.26 (range 49-90, SD 8.9). MPLIF was performed at five levels in one patient, four levels in 29 patients, three levels in 20 patients, and two levels in 14 patients. There were a total of 14 (21.87%) major, minor and mechanical complications. There were no procedure-related mortalities. The average COMI and Eq5d scores improved significantly post-surgery, and this improvement was maintained at a mean follow-up of up to two years. CONCLUSIONS: Multilevel posterior interbody fusion is a safe procedure, and in selected cases can result in good clinical and radiological outcomes with improvement in patient quality of life.

The safety, efficacy, and cost-effectiveness of intraoperative cell salvage in metastatic spine tumor surgery.

BACKGROUND CONTEXT: Metastatic spine tumor surgery (MSTS) is associated with substantial blood loss, therefore leading to high morbidity and mortality. Although intraoperative cell salvage with leukocyte depletion filter (IOCS-LDF) has been studied as an effective means of reducing blood loss in other surgical settings, including the spine, no study has yet analyzed the efficacy of reinfusion of salvaged blood in reducing the need for allogenic blood transfusion in patients who have had surgery for MSTS. PURPOSE: This study aimed to analyze the efficacy, safety, and cost-effectiveness of using IOCS-LDF in MSTS. STUDY DESIGN: This is a retrospective controlled study. PATIENT SAMPLE: A total of 176 patients undergoing MSTS were included in the study. METHODS: All patients undergoing MSTS at a single center between February 2010 and December 2014 were included in the study. The primary outcome measure was the use of autologous blood transfusion. Secondary outcome measures included hospital stay, survival time, complications, and procedural costs. The key predictor variable was whether IOCS-LDF was used during surgery. Logistic and linear regression analyses were conducted by controlling variables such as tumor type, number of diseased vertebrae, approach, number and site of stabilized segments, operation time, preoperative anemia, American Society of Anesthesiologists (ASA) grade, age, gender, and body mass index (BMI). No funding was obtained and there are no conflicts of interest to be declared. RESULTS: Data included 63 cases (IOCS-LDF) and 113 controls (non-IOCS-LDF). Intraoperative cell salvage with LDF utilization was substantively and significantly associated with a lower likelihood of allogenic blood transfusion (OR=0.407, p=.03). Intraoperative cell salvage with LDF was cost neutral (p=.88). Average hospital stay was 3.76 days shorter among IOCS-LDF patients (p=.03). Patient survival and complication rates were comparable in both groups. CONCLUSIONS: We have demonstrated that the use of IOCS-LDF in MSTS reduces the need for postoperative allogenic blood transfusion while maintaining satisfactory postoperative hemoglobin. We recommend routine use of IOCS-LDF in MSTS for its safety, efficacy, and potential cost benefit.

Adolescent Idiopathic Scoliosis.

BACKGROUND: Scoliosis refers to deviation of spine greater than 10 degrees in the coronal plane. Idiopathic Scoliosis is the most common spinal deformity that develops in otherwise healthy children. The sub types of scoliosis are based on the age of the child at presentation. Adolescent idiopathic scoliosis (AIS) by definition occurs in children over the age of 10 years until skeletal maturity. OBJECTIVE: The objective of this review is to outline the features of AIS to allow the physician to recognise this condition and commence early treatment, thereby optimizing patient outcome. METHOD: A thorough literature search was performed using available databases, including Pubmed and Embase, to cover important research published covering AIS. CONCLUSION: AIS results in higher incidence of back pain and discontent with body image. Curves greater than 50 degrees in thoracic region and greater than 30 degrees in lumbar region progress at a rate of 0.5 to 1 degree per year into adulthood. Curves greater than 60 degrees can lead to pulmonary functional deficit. Therefore once the disease is recognized, effective treatment should be instituted to address the deformity and prevention of its long-term sequelae.

Latarjet Fixation: A Cadaveric Biomechanical Study Evaluating Cortical and Cannulated Screw Fixation.

BACKGROUND: Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. PURPOSE: To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws. RESULTS: All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144). CONCLUSION: There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws. CLINICAL RELEVANCE: Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option.

Correction of sagittal plane deformity and predictive factors for a favourable radiological outcome following multilevel posterior lumbar interbody fusion for mild degenerative scoliosis.

PURPOSE: Limited data is available in the literature on the radiographic results of multilevel posterior lumbar interbody fusion (MPLIF) in the treatment of degenerative scoliosis. The objective of our study was to evaluate the segmental and global correction achieved with MPLIF in the treatment of degenerative scoliosis. METHODS: Between 2009 and 2014, 42 patients underwent correction of degenerative scoliosis with MPLIF. Several radiological parameters were measured pre- and post-operatively by two independent observers. A statistical analysis was performed to assess the inter-observer reliability of the measurements and to determine the degree of segmental correction achieved at each intervertebral disc. Using sagittal vertical axis (SVA) less than 47 mm; lumbar lordosis (LL) within 11° of pelvic incidence (PI); and pelvic tilt (PT) no more than 22° as radiological criteria for procedural acceptability, we determined predictive factors for a favourable radiological outcome. RESULTS: Forty-two patients (34 female) were included in our study. The average amount of correction per segment was 6.2°. The overall correction achieved with MPLIF was 16.6°. Twenty-six of the 42 patients (61.9 %) had post-operative SVA values less than 47 mm. Nineteen of the 42 patients (45.2 %) had average post-operative LL within 11° of the PI. Sixteen of the 42 patients (38.1 %) had PT less than 22°. Younger age, female gender and a low pre-operative PT were significantly associated with the attainment of a satisfactory sagittal alignment. CONCLUSION: Our results demonstrate that a satisfactory correction can be achieved in degenerative scoliosis with MPLIF. In addition, our results show that it is significantly more likely to achieve a satisfactory radiological outcome in younger, female patients with low pre-operative PT.

Change in spinal height following correction of adolescent idiopathic scoliosis.

BACKGROUND CONTEXT: Corrective surgery for adolescent idiopathic scoliosis (AIS) leads to vertical growth arrest of the instrumented spine. This might be offset by the immediate gain in spinal height (SH) as a result of correction of the curvature. PURPOSE: This study aimed to identify predictors of gain in SH following corrective surgery for AIS. We present a unique model to predict postoperative height prior to intervention, which could contribute to the preoperative counseling and consenting process. STUDY DESIGN: This was a retrospective case series. All surgeries were performed by one of four substantive pediatric spinal surgeons within a single regional center over a 3.5-year period. PATIENT SAMPLE: There were 104 patients who had instrumented posterior spinal fusion for AIS included. There were 93 females, and the age range was from 11 to 17 years. All patients had posterior instrumented fusion using rods and anchors (pedicle screws±hooks). OUTCOME MEASURES: Postoperative SH was the primary outcome measure. The SH (C7-L5) and Cobb angles were measured from a pre- and postoperative standing X-ray of each patient. METHODS: Variables associated with patients (demographic and radiological) and the surgical constructs were analyzed for predictability of height gain. A model was derived including only significant predictors of substantive importance using hierarchical regression methods. Cross-validation procedures verified the adequacy of the model fit. Analysis was performed using IBM SPSS Statistics for Windows version 20.0 (IBM Corp. Armonk, NY, USA). RESULTS: The major curve was thoracic in 90% of cases. The number of vertebrae fused ranged from 5 to 15. The average preoperative Cobb angle was 66°, with an average correction of 45°. The average change in SH was 4.66 cm (SD 2.13 cm). The model presented included preoperative height, preoperative Cobb angle, and number of vertebrae within the construct, with coefficients of 1.00 (95% CI: 0.90, 1.09), 0.067 (95% CI: 0.039, 0.095), and 0.26 (95% CI: 0.11, 0.41), respectively. This model had an adjusted-R(2) value of 0.83 and a R(2) for prediction of 0.79, and can be shown to have similar predictive capability as a model comprising a wider range of predictors. CONCLUSION: The greatest postoperative height values following posterior spinal fusion for AIS could be expected from a patient with greater preoperative height and Cobb angle, and whose construct spans a large number of vertebrae.

The pattern of blood loss in adolescent idiopathic scoliosis.

BACKGROUND CONTEXT: Previous studies have shown that modern intraoperative blood-saving techniques dramatically reduce the allogeneic transfusion requirements in surgery for adolescent idiopathic scoliosis (AIS). No studies have looked at the pattern of postoperative hemoglobin (Hb) in AIS patients undergoing corrective spinal surgery and correlated this with the timing of allogeneic transfusion. PURPOSE: To describe the pattern of perioperative blood loss in instrumented surgery for AIS. We look at the recommendations regarding an ideal preoperative Hb, the need for preoperative cross-matching, and the timing of postoperative Hb analysis. STUDY DESIGN: This was a retrospective case series. Surgeries were performed by one of four substantive pediatric spinal surgeons within a single regional center over a 3-year period. PATIENT SAMPLE: A consecutive series of 86 patients who underwent posterior instrumented fusion for AIS were included: 10 males and 76 females. Mean age was 14 years (range 10-17 years). All patients had posterior instrumented fusion using various blood-saving techniques (eg, cell-saver). All patients were cross-matched preoperatively, and our transfusion trigger value (TTV) was 7 g/dL. OUTCOME MEASURES: Hemoglobin level was the outcome measure. Hemoglobin readings were obtained preoperatively, within 2 hours of surgery, and daily up to 5 days after surgery. This physiologic measure was assessed using routine blood sampling techniques and standardized laboratory processing. METHODS: Patient predictor variables (demographic and surgical) were assessed for association with Hb levels in a hierarchical model, with repeated Hb readings at the lower level being clustered within an individual patient at the upper level of the structure. The variation of Hb levels within individuals was compared with mean levels in different individuals via the variance partition coefficient of the model structure. RESULTS: No patients required intraoperative allogeneic transfusion. Only four patients (4.65%) received allogeneic transfusion, all within 2 days of surgery. A clinically important drop in Hb occurred within the first 2 postoperative days, rising thereafter. The average postoperative drop in Hb was 4.1 g/dL. Young males had lower postoperative Hb values. Neither the preoperative curve magnitude (Cobb angle of major curve) nor the number of vertebrae/levels fused significantly affected the blood loss. CONCLUSIONS: We recommend setting a minimum preoperative Hb value that is 5 g/dL higher than your TTV. Because no patients required an intraoperative transfusion when using modern blood-saving techniques, preoperative cross-matching is unnecessary and potentially wasteful of blood reserves. Hemoglobin analysis beyond the second postoperative day is unnecessary unless clinically indicated.