Proximal junctional kyphosis (PJK) is defined as adjacent segment kyphosis >10° between the upper instrumented vertebrae and the vertebrae 2 levels above following scoliosis surgery. There are few studies investigating the predictors and clinical sequelae involved with this relatively common complication. Our purpose was to determine the radiographic predictors of post-op PJK and to examine the association between PJK and pain/HRQOL following surgery for AIS.

The Post-Operative Recovery after Scoliosis Correction: Home Experience (PORSCHE) study was a prospective multicenter cohort of AIS patients undergoing spinal fusion surgery. Pre-op and minimum 2 year f/u scoliosis and sagittal spinopelvic parameters (thoracic kyphosis–TK, lordosis–LL, pelvic tilt-PT, sacral slope-SS, pelvic incidence-PI) were measured and compared to numeric rating scale for pain (NRS) score, SRS-30 HRQOL and to the presence or absence of PJK (proximal junctional angle >100). Continuous and categorical variables were assessed using logistic regression and binomial variables were compared to binomial outcomes using chi-square.

163 (137 females) patients from 8 Canadian centers met inclusion criteria. At final f/u, PJK was present in 27 patients (17%). Pre-op means for PJK vs No PJK: Age 14.1 vs 14.7yr; females 85 vs 86%; scoliosis 57±22 vs 62±15deg; TK 28±18 vs 19±16deg ∗, LL 62±11 vs 60±12deg, PT 8±12 vs 10±10deg, SS 39±8 vs 41±9deg, PI 47±14 vs 52±13deg, SVA −9±30 vs −7±31mm. Final f/u for PJK vs No PJK: Scoliosis 20±11 vs 18±8deg, final TK 26±12 vs 19±10deg∗, LL 60±11 vs 57±12deg, PT 9±12 vs 12±13deg, SS 39±9 vs 41±9deg, PI 48±17 vs 52±14deg, SVA −23±26 vs −9±32mm∗. Significant findings: Pre-op kyphosis >40deg has an odds ratio (OR) of 4.41 (1.50–12.92) for developing PJK∗. The presence of PJK was not associated with any significant differences in NRS or SRS-30. ∗denotes p<0.05.

This prospective multicenter cohort of AIS patients demonstrated a 17% risk of developing PJK. Pre-op thoracic kyphosis >40deg was associated with the development of PJK; however, the presence of PJK was not associated with increased pain or decreased HRQOL.

Adolescent idiopathic scoliosis (AIS) is a poorly understood progressive curvature of the spine. The 3-dimmensionnal spinal deformation brings abnormal biomechanical stresses on the load-bearing organs. We have recently reported for the first time the presence of facet joint cartilage degeneration comparable to age-related osteoarthritis in scoliotic adolescents. To better understand the degenerative mechanisms and explore new therapeutic possibilities, we focused on Toll-like receptors (TLRs) which are germline-encoded pattern recognition receptors that recognize pathogens and endogenous proteins such as fragmented extracellular matrix components (alarmins) present in intervertebral discs (IVD) and articular cartilage. Once activated, they regulate the production pro-inflammatory cytokines, proteases and neurotrophins which can lead to matrix catabolism, inflammation and potentially pain. These mechanisms have however not been studied in the context of AIS or facet joints.

Facet joints of AIS patients undergoing corrective surgery and of cadaveric donors (non-scoliotic) were collected from consenting patients or organ donors with ethical approval. Cartilage biopsies and chondrocytes were isolated using 3mm biopsy punches and collagenase type 2 digestion respectively. qPCR was used to assess gene expression of the degenerative factors (MMP3, MMP13, IL-1ß, IL-6, IL-8) The biopsies were cut into two equal halves, one was treated for 4 days with a TLR2 agonist (Pam2CSK4, Invivogen) in serum-free chondrocyte media while the other one was cultured in media alone. MMP3, MMP13, IL-6 and IL-8 ELISAs and DMMB assays were performed on the biopsy cultured media. The ex vivo cartilage was then fixed, cryosectionned and also stained with SafraninO-Fast Green dyes.

Baseline gene expression levels of TLR1,−2,−4,−6 were all upregulated in scoliotic chondodryctes compared to non-scoliotic. Pearson correlation analysis revealed that all TLR1,−2,−4,−6 gene expression correlated strongly and significantly with degenerative markers (MMP3, MMP13, IL-6, IL-8) in scoliotic chondrocytes but not in non-scoliotic. (Figure 1) When monolayer facet joint chondrocytes were activated with Pam2CSk4, there was a significant upregulation in previously described degenerative markers, TLR2 and NGF, a potent neurotrophin. These findings were strengthened by protein secretion analysis of select markers such as MMP-3, −13, IL-6 and IL-8 which were all upregulated after TLR2 activation. The scoliotic biopsies which were treated with Pam2CSK4 had a significant loss of proteoglycan content as shown by histology, was reflected in the proteoglycan content found in the media by DMMB.

TLR gene expression levels were upregulated and correlated with proteases and pro-inflammatory cytokines in degenerating scoliotic cartilage, suggesting they promote cartilage degradation, especially considering the lack of correlations in non-scoliotic healthy cartilage. Furthermore, when TLRs are activated by Pam2CSK4 it triggers the release of the same proteases and pro-inflammatory cytokines in our ex vivo experiment. All this exacerbates the loss of proteoglycan in the cartilage ex vivo model after four days of insult with a TLR2 specific agonist. These results suggest that TLRs are an important pathway partaking in the cartilage degeneration of scoliotic facet joints and potentially all cartilage beyond our scope. Future studies aim at blocking TLRs to alleviate proteolysis and inflammation.

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The objective of this paper is to demonstrate the difference in post-operative complication rates between Computer-assisted surgery (CAS) and conventional techniques in spine surgery. Several studies have shown that the accuracy of pedicle screw placement significantly improves with use of CAS. Yet, few studies have compared the incidence of post-operative complications between CAS and conventional techniques.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent posterior lumbar fusion from 2011 to 2013. Multivariate analysis was conducted to demonstrate the difference in post-operative complication rates between CAS and conventional techniques in spine surgery.

Out of 15,222 patients, 14,382 (95.1%) were operated with conventional techniques and 740 (4.90%) were operated with CAS. Multivariate analysis showed that patients in the CAS group had less odds to experience adverse events post-operatively (OR 0.57, P <0.001).

This paper examined the complications in lumbar spinal surgery with or without the use of CAS. These results suggest that CAS may provide a safer technique for implant placement in lumbar fusion surgeries.

Cervical spine fusion have gained interest in the literature since these procedures are now ever more frequently being performed in an outpatient setting with few complications and acceptable results. The purpose of this study was to assess the rate of blood transfusion after cervical fusion surgery, and its effect, if any on complication rates.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent cervical fusion surgery from 2010 to 2013. Univariate and multivariate regression analysis was used to determine post-operative complications associated with transfusion and cervical fusion.

We identified 11,588 patients who had cervical spine fusion between 2010 and 2013. The overall rate of transfusion was found to be 1.47%. All transfused patients were found to have increased risk of: venous thromboembolism (TBE) (OR 3.19, CI: 1.16–8.77), myocardial infarction (MI) (OR 9.12, CI: 2.53–32.8), increased length of stay (LOS) (OR 28.03, CI: 14.28–55.01) and mortality (OR 4.14, CI: 1.44–11.93). Single level fusion had increased risk of: TBE (OR 3.37, CI: 1.01–11.33), MI (OR 10.5, CI: 1.88–59.89), and LOS (OR 14.79, CI: 8.2–26.67). Multilevel fusion had increased risk of: TBE (OR 5.64, CI: 1.15–27.6), surgical site infection (OR 16.29, CI: 3.34–79.49), MI (OR 10.84, CI: 2.01–58.55), LOS (OR 26.56, CI: 11.8–59.78) and mortality (OR 10.24, CI: 2.45–42.71). ACDF surgery had an increased risk of: TBE (OR 4.87, CI: 1.04–22.82), surgical site infection (OR 9.73, CI: 2.14–44.1), MI (OR 9.88, CI: 1.87–52.2), LOS (OR 28.34, CI: 13.79–58.21) and mortality (OR 6.3, CI: 1.76–22.48). Posterior fusion surgery had increased risk of: MI (OR 10.45, CI: 1.42–77.12) and LOS (OR 4.42, CI: 2.68–7.29).

Our results demonstrate that although cervical fusions can be done as outpatient procedures special precautions and investigations should be done for patients who receive transfusion after cervical fusion surgery. These patients are demonstrated to have higher rate of MI, DVT, wound infection and mortality when compared to those who do not receive transfusion.

Hemorrhage and transfusion requirements in spine surgery are common. This is especially true for thoracic and lumbar fusion surgeries. The purpose of this papersi to determine predictive factors for transfusion and their effect on short-term post-operative outcomes for thoracic and lumbar fusions.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent lumbar or thoracic fusion surgery from 2010 to 2013. Univariate and multivariate regression analysis was used to determine predictive factors and post-operative complications associated with transfusion.

A total of 14,249 patients were included in this study; 13,586 had lumbar fusion and 663 had thoracic fusion surgery. The prevalence of transfusion was 35% for thoracic fusion and 17.5% for lumbar fusion. The multivariate analysis showed that age between 50–60 (OR 1.38, CI: 1.23–1.54), age between 61–70 (OR 1.65, CI: 1.40–1.95), dyspnea (OR 1.11, CI: 1.02–1.23), hypertension (OR 1.14, CI: 1.02–1.27), ASA class (OR 1.73, 1.18–1.45), pre-operative blood transfusion (OR 1.91, CI: 1.04–3.49), and extended surgical time (OR 4.51, CI: 4.09–4.98) were predictors of blood transfusion requirements for lumbar fusion. While only pre-operative BUN (OR 1.04, CI: 1.01–1.06) and extended surgical time (OR 4.70, CI: 3.12–6.96) were predictors of transfusion for thoracic fusion. In contrast, higher pre-operative hematocrit was protective against transfusion. Patients transfused who underwent lumbar fusion had an increased risk to develop superficial wound infection, deep wound infection, venous thromboembolism, myocardial infarction and had longer length of hospital stay. Patients transfused who underwent thoracic fusion were more likely to have venous thromboembolism and extended length of hospital stay. However, mortality was not associated with blood transfusion.

This study used a large database to characterise the incidence, predictors and post-operative complications associated with blood transfusion in thoracic and lumbar fusion surgeries. Pre- and post-operative planning for patients deemed to be at high-risk of requiring blood transfusion should be considered to reduce post-operative complication in this population.

Referral patterns in spine clinic of young patients with suspected scoliosis is suboptimal with 19% of late referrals and 42% of inappropriate referrals. Patients' triage and prioritisation in spine clinic is a strategy to ensure that health care allocation is done according to the level of health needs, favoring effective management and efficient use of health care resources use. The objective of the study is to elaborate a model for triage and prioritisation of young patients in spine clinic based on expert consensus and literature on best practices.

This projects was structured in three parts: 1)We documented best evidence. We conducted a review of empirical studies evaluating triage and prioritisation initiatives in order to identify key components for intervention success. 2)We elaborate a model of health care delivery with the professionals of a local paediatric spine clinic. In this model, the triage and prioritisation algorithm was developed from list of potential factors (demographics, signs and perceived symptoms, provisional diagnoses and known co-morbidities, results of preliminary physical examination and radiological findings) that was submitted to five paediatric orthopaedic surgeons for rating according to their potential relevance to orient prioritisation decisions. 3) We compared the professionals' model of health care delivery to the literature synthesis in order to propose the best model.

Seven key components of triage and prioritisation systems were identified: centralised review of referral requests, list of consensual objectives criteria for triage, fast track evaluation of urgent cases, selection of cases for management at point of triage, cases prioritisation to main consultant, multidisciplinary evaluation and alternatives pathways. The consensual decision algorithm confirmed that cases who should be seen in priority are immature patients presenting with a significant trunk deformity. In addition, presence of persisting neurological symptoms, severe incapacitating pain or night pain, as well as abnormal scan or MRI findings were considered as urgent/PI priority. Cases characteristics for evaluation by nurse practitioners as well as alternative pathways of management were defined. Acceptability, compatibility, clinical relevance and discriminant capacity of the new model of health care delivery were satisfactorily demonstrated.

Consensus was easily reached between the five respondents on factors supporting decisions to prioritise patients in spine clinic for suspected spinal deformity. Refinements to the initially proposed model according the identified key features from the literature, led to a final model of health care delivery that is evidence-base, feasible and coherent with the local context. Future implementation of this model should facilitate timely and appropriate health care delivery and best use of health care resources according to patients' needs.

Introduction

Originally, the vertical expandable titanium rib (VEPTR™) was developed to treat children with Thoracic insufficiency syndrome secondary to fused ribs and congenital scoliosis. Over the years its usage has widen and is currently being used to treat all etiology of early onset scoliosis (EOS). A major draw back remains the size of the titanium VEPTR™ implant. In keeping with the new trend of chrome-cobalt alloy (CoCr). spinal implants, we set out to explore if redesigning the VEPTR™ was mechanically sound. The aim of this study was twofold. Firstly, we investigate the mechanical properties of a VEPTR™ made with CoCr alloy compared to that of titanium alloy. Secondly we investigated how much we could down size the VEPTR™.

Purpose

Disc degeneration is known to occur early in adult life, but at present there is no medical treatment to reverse or even retard the problem. Development of medical treatments is complicated by the lack of a validated long term organ culture model in which therapeutic candidates can be studied. The objective of this study was to optimize and validate an organ culture system for intact human intervertebral disc (IVD), which could be used subsequently to determine whether synthetic peptide growth factors can stimulate disc cell metabolism and initiate a repair response.

Background: Surgical treatment of spinal deformities is complex and is performed by a limited number of spine surgeons. To obtain adequate radiological and clinical correction, a large amount of clinical experience is required when planning corrective surgery because of the enormous amount of patient related variables, and the many surgical techniques (e.g. rod rotation vs translation, pedicle screws vs hooks, anterior vs posterior).

The widely used classification systems (King and Lenke) are useful for documentation of the deformities. Unfortunately explicit guidelines for surgery are not clear. A multi-centre database with pre and postoperative patient data including photographic images and x-rays will be very useful in decision making. It will allow surgeons to find similar cases in the database that will help them in their decision making for surgical planning and execution. Furthermore it will provide extensive data to perform outcome studies, and to develop general treatment guidelines. Surgery for spinal deformities will become more evidence based and less dependent on the individual surgeons judgement.

Methods: A modern web-based database system, Scolisoft was developed for documenting patient data and curve characteristics. The system contains patient data (demographics etc), radiological data (AP, Lat, bending films), classification of curve patterns according to the often-used classification systems and information about the surgical procedure. It includes pre and postoperative radiological data and clinical photographs.

The patient data can also be stored and printed as a PDF-file, so that it can be used as a patient chart and for patient information purposes.

Scolisoft allows the user to select patients based on all the individual characteristics, e.g. curve classification. For pre-operative planning of a specific deformity, a cohort of patients with the same deformity (patient demographics, curve pattern, bending films etc) can be selected and the postoperative results viewed.

With the same selection tool, cohorts of patients can be selected for outcome studies.

Furthermore Scolisoft provides the possibility of discussing difficult cases with other spine surgeons using the system.

Finally, complications are registered according to the existing Scoliosis Research Society complication registry system.

Experiences: Data of more than 200 patients have been entered into the former PC application system. The current web based system has 60 cases that have been entered during its trial phase. Most cases have been adolescent or adult idiopathic scoliosis. Forty two surgeons have used the software and eight surgeons have participated in entering cases. The web-based version has shown to be very user friendly. Submitting the radiological and clinical images is easy (but takes some time). All data input is possible by a simple click of the mouse. Therefore it is relatively easy to learn.

The system already has the possibility for documenting other spine pathology such as sagittal plane deformities, fractures and spondylolisthesis.

Conclusion: Scolisoft is a powerful, user-friendly web-based registry for spinal deformities. It is a very useful tool in planning spinal deformity surgery and research. In this time of evidence-based medicine, it is time to take the planning of scoliosis surgery out of the realm of myth, and this database is a strong step in that direction.

Introduction: Spinal deformities and scoliosis in particular, represent the most prevalent type of orthopaedic deformities in children and adolescents. At present, the most significant problem for clinicians is that there is no proven method or test available to identify children or adolescents at risk of developing AIS or to identify which of the affected individuals are at risk of progression. As a consequence, the application of current treatments, such as bracing or surgical correction, has to be delayed until a significant deformity is detected or until a significant progression is clearly demonstrated, resulting in a delayed and less optimal treatment. Among patients with AIS needing treatment, 80% to 90% will be treated by brace and 10% will need surgery to correct the deformity by spinal instrumentation and fusion of the thoracic and/or lumbar spine. About 15000 such surgeries are done every year in North America, resulting in significant psychological and physical morbidity. Moreover, there is no pharmacotherapy available to either prevent or reduce spinal deformities due mainly to our limited knowledge of AIS aetiopathogenesis. We have recently reconciled the role of melatonin in AIS aetiopathogenesis by demonstrating a melatonin signalling dysfunction occurring in a cell autonomous manner in cells derived from AIS patients exhibiting severe scoliotic deformities. This defect could potentially explain the majority of abnormalities reported in AIS since melatonin receptors and signalling activities are normally found in all tissues and systems affected in AIS, thus offering a very innovative and unifying concept to explain the aetiology of AIS. Moreover, several lines of evidence suggested that inactivation of Gi proteins by an increased phosphorylation of serine residues could be at the source of this signalling defect in AIS. The goals of that study were to assess the possibility to establish a molecular classification of AIS patients and to demonstrate the feasibility to correct this melatonin signalling defect in cells of AIS patients using therapeutic compounds.

Methods: Primary cell cultures were prepared from musculoskeletal tissues of AIS patients (n=150) and age- and gender-matched controls (n=35) obtained intra-operatively. An informed consent was obtained for each subject as approved by our Institutional Ethical Committee. The osteoblasts, the bone-forming cells, were selected to assess whether or not an alteration of melatonin signalling pathway occurs in AIS and accordingly to identify which component of the melatonin transduction machinery could be involved. Co-immunoprecipitation experiments with membrane extracts were performed to identify interacting molecules with key components of melatonin signal transduction machinery. The functionality of melatonin signalling was assessed by investigating the ability of Gi proteins to inhibit stimulated adenyl cyclase activity in osteoblast cultures. Inhibition curves of cAMP production were generated by adding melatonin to the forskolin-containing samples in concentrations ranging from 10-11M to 10-5M in a final volume of 1 ml of _-MEM media containing 0.2% bovine serum albumin (BSA) alone or in presence of 2.5 _M of therapeutic compound A or therapeutic compound B (the nature of both compounds tested cannot be disclosed at this stage). The cAMP content was determined using an enzyme immunoassay kit (Amersham-Pharmacia Biosciences). All assays were performed in duplicate. A non-parametric test, the Wilcoxon matched pairs test was performed to verify the significance between 2 means. Significance was defined as P< 0.05.

Results: Osteoblasts from patients with AIS showed a lack or a markedly reduced inhibition of forskolin-stimulated adenyl cyclase activity by melatonin generating three distinct response-curves corresponding to three functional groups. In order to identify candidate genes involved in AIS aetiopathogenesis, we focused our attention on known kinases and phosphatases modulating Gi protein functions and characterised their interacting partners. Interestingly, PKC_ was initially targeted owing to its property to phosphorylate Gi proteins in vitro. Indeed, in normal osteoblast interactions occurring between MT2 melatonin receptor and RACK1 (a cytosolic protein that bind to and stabilises the actives form of PKC and permits its translocation to different sites within the cells) and PKC_ were detected although those interactions among different AIS patients were altered. Interestingly, treatment with compound A or B rescued melatonin signal defect in cells derived from 36% and 47% of AIS patients respectively. Overall, melatonin signal transduction was restored in cells of 64% of AIS patients (23/36) when treated by one of these therapeutic compounds.

Conclusions: The functional classification of AIS patients is correlated at the molecular level by distinct interactions between key molecules normally involved in melatonin signal transduction in spite that these patients exhibited the same curve type (right thoracic, Lenke type 1). Collectively, these data strongly argue that traditional curve pattern classification is not a relevant stratification of AIS patients to identify its genetic causes. Moreover, using that molecular system we have demonstrated also the possibility to identify therapeutic compounds to rescue the melatonin signalling defect observed in AIS without any prior knowledge of mutations in any defective genes causing AIS because we are measuring a function.

Research project supported by La Fondation Yves Cotrel de l’Institut de France

Purpose of the study: We report a series of 12 patients who underwent surgery in 2003 or 2004 for spinal shortening as treatment for thoracic or lumbar metastasis.

Material and method: This series included seven females and five males, mean age 56.5 years (range 34–80 years). The operation was a resection of the vertebral body in a one-stage procedure. A simple posterior approach was used for two patients and a wider costotransversectomy approach was required for ten. Posterior fixation was installed with pedicle screws in the two vertebrae above and two below the resection. Mean operative time was 343 minutes (range 260–420 min). Mean blood loss was 2380 cc (range 600–5000). There were few surgery-related complications: one dural breach and one pulmonary breach.

Results: The decision to undertake surgery was made on the basis of neurological problems in seven patients. All patients were Frankel class C, unable to walk. Among these patients, five died in less than six months. For the two survivors, they were scored 7 on the Tokuhashi scale. The remainder scored 5. For the two survivors, one recovered walking capacity (Frankel D) and the other achieved a normal status (Frankel E). The five other patients underwent surgery for pain related to a kyphosis callus threatening the cord. We used the Karnofsky and the Oswestry score to analyze outcome. The score did not regress in any of the patients after surgery. Three patients improved their score significantly. The three others had an unchanged score. The best correction of the kyphosis callus was obtained when the vertebral collapse was greater than 50%. The preoperative regional deformity was measured at 23.2° (range 15–35°) which postoperatively reached 0.5° (range 20 to −17°).

Conclusion: This technique for spinal shortening appears to be a better alternative to anterior reconstruction, especially when the vertebral collapse is greater than 50%. In this context, this palliative surgery enables improved quality-of-life for a patient with often advanced disease.

Purpose of the study: We report the results of a series of seven cases of non-tuberculos infectious lumbar spondylodiscitis treated by posterior instrumentation and secondary anterior curettage of the infectious focus with bone grafting. This particular osteosynthesis method produces a short monosegmentary fixation limited to the space of the infected disc.

Material and methods: The series included six men and one woman (mean age 61.7 years, age range 37–82 years). The causal germ was identified in all cases: Staphylococcus aureus in five, and in one each, Staphylococcus epidermidis and Pseudomonas aeruginosa. Levels were L1L2 in one, L2L3 in two, L3L4 in three and L5S1 in one. Predisposing factors were history of prostatic cancer in two patients, coronary heart disease in one and chronic renal failure in one. One patient had received corticosteroid injections and two had no recognized co-morbid conditions. The surgical procedure was undertaken due to persistent pain in three patients (one with quadriceps amyotrophy and weakness), spinal instability with risk of neurological injury in two, and after failure of medical treatment in two patients who had persistent abscesses.

Results: Excepting one patient who died from renal failure four months after the surgical procedure, mean follow-up was 31.5 months (range six months to six years). Outcome was excellent in four patients, good in one, and a failure in one patient who was operated on because of instability. Failure of the instrumentation required surgical revision to extend the initial assembly. At last follow-up, all patients had achieved fusion of the instrumented zone and were considered to be cured of their infection.

Discussion: Classically, it is advisable to avoid instrumenting close to an infectious area in order to avoid the vicious circle of infection. Configurations described in the literature are usually extensive, blocking healthy levels beyond the infected area and compromising spinal mobility. However, a short instrumentation limited to one segment can be proposed when the end plates at the outer limits of the infectious focus are theoretically healthy. Careful analysis of the imaging data is required to carefully select patients who can benefit from this short configuration. Magnetic resonance imaging is most helpful.

Classic management of large and stiff thoracic scoliotic curves in the adolescent comprise of anterior release followed by posterior instrumentation. However third generation segmental spinal instrumentations have shown increased correction of thoracic curves. Therefore, the indication for an anterior release may no longer be required. We reviewed our database for cases with thoracic curves with Cobb angle between 70 and 90° that we had only done posterior surgery. We found that with adequate posterior release, and the use of third generation segmental instrumentation there is no need for anterior release even for curves in the 70–90° range.

Large and stiff thoracic scoliotic curves in the adolescent represent a classic indication of anterior release before posterior spinal instrumentation.

To assess if third generation segmental posterior instrumentation can omit the need of anterior surgery in large and stiff thoracic curves.

An independent observer, reviewed in a retrospective fashion our electronic database of adolescent scoliosis surgery (Scolisoft) with the following query: Thoracic curves, Cobb angle between 70 and 90° degrees and posterior surgery only. There was nineteen patients who fit the criteria. Out of these, four were judged to flexible (bends < than 45°) and were not included. Fifteen patients (mean age 13.6) with thoracic scoliosis with average Cobb 78.5° with a flexibility index of 32.5% were analyzed. (mean f/u: twenty-eight months)

Postoperatively the thoracic Cobb angle measured on average 34.8° (25° −45°), which represents a correction rate of 54 % (range, 40.0–67.1%) and remained unchanged at the last follow-up (35°). Sagittal alignment improved from an average 11° to 18°. There were two complications (one excessive bleeding and one infection). Coronal balance was improved, as was shoulder balance. All patients reported satisfactory results except the patient with an adding-on phenomena

In the literature most of the results of anterior thora-coscopic release and posterior surgery give a percentage of Cobb angle correction similar or inferior (averaging 50%) to our series for an average initial Cobb angle of less magnitude. With adequate posterior release, and the use of third generation segmental instrumentation there is no need for anterior release even for curves in the 70–90° range.

“Delta fixation” was developed to treat low-grade L5 isthmic spondylolisthesis. It involves placement of pedicle screws into L5 and from S1 through the L5/S1 disc into L5 (Fig.1). A biomechanical comparison to standard Posterior Lumbar Interbody Fusion (PLIF) with two anterior cages and pedicle screws in L5 and S1 was made. Eight fresh frozen human specimens were instrumented with both fixations and tested. Delta fixation was significantly more stable in resisting rotation. It requires less manipulation of the nerve roots and spares the cost of the fusion cages.

Our objective is to compare the stability of Delta versus PLIF fixation in the treatment of low grade isthmic spondylolisthesis

Delta fixation provides superior initial stability, and therefore is an acceptable alternative to PLIF for the treatment of low grade isthmic spondylolisthesis of L5-S1.

Symptomatic low-grade isthmic spondylolisthesis of L5 is often managed with PLIF. This procedure requires extensive manipulation of the cauda equine, posterior resection of the disc and the placement of two inter-body cages as spacers in addition to pedicle screws in L5 and S1.

Delta Fixation has been developed to provide stable fixation with less nerve root manipulation and without the use of inter-body cages. It is therefore a safer alternative method of fixation that spares the additional cost of the fusion cages.

When comparing Delta fixation to PLIF fixation the only statistically significant difference was found in axial rotation. Delta fixation had 2.05 degrees less ROM and 0.90 degrees less NZ compared to PLIF fixation with P values of 0.0052 and 0.0104 respectively. This demonstrates that the delta fixation is more stable than PLIF fixation.

Eight fresh frozen human spines were used. Matched pairs were created and block randomization used to create two groups: PLIF fixation and Delta fixation groups. The specimens were instrumented with a grade II spondylolisthesis of L5-S1, tested, and then re-instrumented with the alternative fixation and tested again. Vertical displacement, axial rotation, flexion– extension and side bending were tested using an MTS machine.

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Purpose: Recently, we highlighted a dysfunction in the melatonin signalling pathway in the osteoblasts from adolescent idiopathic scoliosis patients (AIS). The objective of this project is to verify if in the cells coming from the SIA patients, estrogens interfere with melatonin signalling pathways and to identify mechanisms through which these effects are carried out.

Methods: The effects of estrogens on the melatonin signalling pathway, in osteoblasts from AIS patients (n=7), were determined by measuring the capacity of the Gi proteins to inhibit the accumulation of cAMP. The osteoblasts were incubated in the presence of increasing amounts of melatonin (10–11 to 10–5 M) with or without 17-& #946;-estradiol in physiological concentrations (10–10 M) (n=7). Moreover, coimmunoprecipitations using anti-phosphoserine antibodies were carried out and then followed with a Western blot in order to detect melatonin receptors (MT1 and MT2).

Results: The intracellular level of cAMP is higher in the presence of a physiological concentration of 17-& #946;-estradiol among scoliotic patients compared to the level observed in the presence of melatonin alone. Moreover, the preliminary results of the coimmunoprecipitations seem to show an increase in the phosphorylation of proteins interacting with MT1 and MT2 receptors. The precise nature of these proteins remains to be identified.

Conclusions: These results seem to show the antagonistic effects of the 17-& #946;-estradiol on the melatonin signalling pathway in the osteoblasts from AIS patients. However, more cAMP dosages in the presence and absence of 17-& #946;-estradiol are underway so as to increase the number of patients. The results of this study could contribute to the development of the first molecular screening tests as well as the development of new therapeutic approaches.

Introduction: Historically, anterior spinal surgery for scoliosis has led to better coronal correction, though at the expense of sagittal alignment specifically at the thoracolumbar junction. The purpose of the study was to ascertain the effectiveness in maintenance of coronal and sagittal balance of anterior spinal surgery and instrumentation for AIS.

Methods: 17 patients with idiopathic scoliosis treated with anterior spinal fusion using a single rod AO USS construct were reviewed in a retrospective fashion. Inclusion in study group required a minimum two years follow-up with complete radiographic and clinical follow up.

Results: There were 14 lumbar curves of which seven were King I and seven thoracolumbar / lumbar curves. Seven patients had supplemental structural anterior support in the lumbar spine. Four had femoral allograft rings and three had cages (2 Harms, 1 Synex cages). Three thoracic curves were operated on of which two were King III, and one King II. The mean pre-operative Cobb angle was corrected from 48° to 14° post-op and 16° on the last follow-up (24 to 53 months) representing 71% of correction. Apical vertebral translation was corrected to 70%, comparable to the 60% correction of trunk shift at last follow-up.

Sagittal contour of instrumented segment for the thoracic curve did not change. The pre-operative sagittal contour across the instrumented levels for the 14 1umbar was 5.6° of lordosis which changed to 0.5° of lordosis post-operatively. At last follow-up it was 2° of kyphosis. Specifically there were 7 of 14 that had greater that 10° of surgically induced kyphosis across the fusion mass. At last follow-up three patients had further kyphosis across the instrumented levels. The overall sagittal vertical axis did not change irrespective of the focal sagittal alignment. There was a net increase in lumbar lordosis below the fusion mass. Three patients had asymptomatic pseudoarthroses. There was no failure of instrumentation and no patient required further surgery.

Conclusion: The authors conclude that single rod anterior spinal instrumentation for AIS is effective in maintaining coronal and sagittal alignment though one needs to pay particular attention to sagittal contour. The increase in lumbar lordosis below the fusion may well explain the maintained sagittal balance.