Predictive factors for critical care dependency after posterior spinal fusion for adolescent idiopathic scoliosis.

Aims: Historically, patients undergoing surgery for adolescent idiopathic scoliosis (AIS) have been nursed postoperatively in a critical care (CC) setting because of the challenges posed by prone positioning, extensive exposures, prolonged operating times, significant blood loss, major intraoperative fluid shifts, cardiopulmonary complications, and difficulty in postoperative pain management. The primary aim of this paper was to determine whether a scoring system, which uses Cobb angle, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and number of levels to be fused, is a valid method of predicting the need for postoperative critical care in AIS patients who are to undergo scoliosis correction with posterior spinal fusion (PSF). Methods: We retrospectively reviewed all AIS patients who had undergone PSF between January 2018 and January 2020 in a specialist tertiary spinal referral centre. All patients were assessed preoperatively in an anaesthetic clinic. Postoperative care was defined as ward-based (WB) or critical care (CC), based on the preoperative FEV1, FVC, major curve Cobb angle, and the planned number of instrumented levels. Results: Overall, 105 patients were enrolled. Their mean age was 15.5 years (11 to 25) with a mean weight of 55 kg (35 to 103). The mean Cobb angle was 68° (38° to 122°). Of these, 38 patients were preoperatively scored to receive postoperative CC. However, only 19% of the cohort (20/105) actually needed CC-level support. Based on these figures, and an average paediatric intensive care unit stay of one day before stepdown to ward-based care, the potential cost-saving on the first postoperative night for this cohort was over £20,000. There was no statistically significant difference between the Total Pathway Score (TPS), the numerical representation of the four factors being assessed, and the actual level of care received (p = 0.052) or the American Society of Anesthesiologists grade (p = 0.187). Binary logistic regression analysis of the TPS variables showed that the preoperative Cobb angle was the only variable which significantly predicted the need for critical care. Conclusion: Most patients undergoing posterior fusion surgery for AIS do not need critical care. Of the readily available preoperative measures, the Cobb angle is the only predictor of the need for higher levels of care, and has a threshold value of 74.5°.

Long-term outcome after surgical treatment of Scheuermann's Kyphosis (SK).

STUDY DESIGN: A retrospective observational cohort study with a minimum follow-up of 10 years of patients who underwent surgery for Scheurmann Kyphosis (SK). OBJECTIVE: Evaluate the long-term clinical and radiological outcome of patients with SK who either underwent combined anterior-posterior surgery or posterior instrumented fusion alone. There is paucity of literature for long-term outcome studies on SK. The current trend is towards only posterior (PSF) surgical correction for SK. The combined strategy of anterior release, fusion and posterior spinal fusion (AF/PSF) for kyphosis correction has become historic relic. Long-term outcome studies comparing the two procedures are lacking in literature. METHODS: 51 patients (30 M: 21F) who underwent surgery for SK at a single centre were reviewed. Nineteen had posterior instrumentation alone (PSF) (Group 1) and 32 underwent combined anterior release, fusion with posterior instrumentation (AF/PSF) (Group 2). The clinical data included age at surgery, gender, flexibility of spine, instrumented spinal levels, use of cages and morcellised rib grafts (in cases where anterior release was done), posterior osteotomies and instrumentation, complications and indications for revision surgery. Preoperative flexibility was determined by hyperextension radiographs. The radiological indices were evaluated in the pre-operative, 2-year post-operative and final follow-up [Thoracic Kyphosis (TK), Lumbar lordosis (LL), Voustinas index (VI), Sacral inclination (SI) and Sagittal vertical axis (SVA)]. The loss of correction and incidence of JK (Junctional Kyphosis) and its relation to fusion levels were assessed. Complications and difference in outcome between the two groups were analyzed. RESULTS: The mean age at surgery for 51 patients was 20.6 years who were followed up for a minimum of 10 years (mean: 14 years; range 10-16 years). The mean age was 18.5 ± 2.2 years and 21.9 ± 4.8 years in groups 1 and 2, respectively. The mean pre- and 2-year post-operative ODIs were 32.6 ± 12.8 and 8.4 ± 5.4, respectively, in group 1 (p < 0.0001) and 30.7 ± 11.7 and 6.4 ± 5.7, respectively, in group 2 (p < 0.0001). The final SRS-22 scores in group 1 and 2 were 4.1 ± 0.4 and 4.0 ± 0.35, respectively (p = 0.88). The preoperative flexibility index was 49.2 ± 4.2 and 43 ± 5.6 in groups 1 and 2, respectively (p < 0.0001). The mean TKs were 81.4° ± 3.8° and 86.1° ± 6.0° for groups 1 and 2, respectively, which corrected to 45.1° ± 2.6° and 47.3° ± 4.8°, respectively, at final follow-up (p < 0.0001). The mean pre-operative LL angle was 60.0° ± 5.0° and 62.4° ± 7.6° in groups 1 and 2, respectively, which at final follow-up was 45.1° ± 4.4° and 48.1° ± 4.8°, respectively (p < 0.0001). The mean pre-operative and final follow-up Voustinas index (VI) in group 1 were 22.9 ± 2.9 and 11.2 ± 1.2, respectively, and in group 2 was 25.9 ± 3.5 and 14.0 ± 2.3, respectively. The mean pre-operative and final follow-up SI angle were 43.6° ± 3.3° and 31.2° ± 2.5° in group 1, respectively, and 44.3° ± 3.5° and 32.1° ± 3.5° in group 2, respectively (p < 0.0001). The pre-operative and final follow-up SVA in group 1 were - 3.3 ± 1.0 cms and - 1.3 ± 0.5 cms, respectively, and in group 2 was - 4.0 ± 1.3cms and - 1.9 ± 1.1cms, respectively (p < 0.0001). Though the magnitude of curve correction in the groups 1 and 2 was significant 36° vs 39° (p = 0.05), there was no significant difference in correction between the two groups. Proximal JK was seen in seven and distal JK in five patients were observed in the whole cohort. CONCLUSION: The long-term clinical outcomes for both PSF and AF/PSF are comparable with reproducible results. No difference was noted in loss of correction and outcome scores between the two groups. The correction of thoracic kyphosis (TK) had a good correlation with ODI. AF/PSF had much higher complications than PSF group. The objective of correcting the sagittal profile and balancing the whole spinal segment on the pelvis can be achieved through single posterior approach with fewer complications.

Enhanced recovery after surgery (ERAS) in adolescent idiopathic scoliosis (AIS): a meta-analysis and systematic review.

STUDY DESIGN: A systematic review reporting on the efficacy of an ERAS protocol in patients undergoing spinal fusion for AIS. OBJECTIVE: To systematically evaluate the relevant literature pertaining to the efficacy of ERAS protocols with respect to the length of stay, complication, and readmission rates in patients undergoing posterior spinal corrective surgery for AIS. ERAS is a multidisciplinary approach aimed at improving outcomes of surgery by a specific evidence-based protocol. The rationale of this rapid recovery regimen is to maintain homeostasis so as to reduce the postoperative stress response and pain. No thorough review of available information for its use in AIS has been published. METHODS: A systematic review of the English language literature was undertaken using search criteria (postoperative recovery AND adolescent idiopathic scoliosis) using the PRISMA guidelines (Jan 1999-May 2020). Isolated case reports and case series with < 5 patients were excluded. Length of stay (LOS), complication and readmission rates were used as outcome measures. Statistical analysis was done using the random effects model. RESULTS: Of a total of 24 articles, 10 studies met the inclusion criteria (9 were Level III and 1 of level IV evidence) and were analyzed. Overall, 1040 patients underwent an ERAS-type protocol following posterior correction of scoliosis and were compared to 959 patients following traditional protocols. There was a significant reduction in the length of stay in patients undergoing ERAS when compared to traditional protocols (p < 0.00001). There was no significant difference in the complication (p = 0.19) or readmission rates (p = 0.30). Each protocol employed a multidisciplinary approach focusing on optimal pain management, nursing care, and physiotherapy. CONCLUSION: This systematic review demonstrates advantages with ERAS protocols by significantly reducing the length of stay without increasing the complications or readmission rates as compared to conventional protocols. However, current literature on ERAS in AIS is restricted largely to retrospective studies with non-randomized data, and initial cohort studies lacking formal control groups. LEVEL OF EVIDENCE: 3.

Schmorl Node-A Cause of Acute Thoracic Pain: A Case Report and Pathophysiological Mechanism.

PURPOSE: We report a case of a patient with an acute symptomatic Schmorl node (SN) that spontaneously resolved with characteristic imaging findings. The extensive hematological investigations also allow some insight as to the likely pathophysiology of the painful lesion. METHODS: Case report of an acute symptomatic SN. RESULTS: A fit and athletic 44-year-old female participant in a competitive paddling event developed atypical thoracic pain and was admitted for further investigation. Normal blood results included complete blood cell count, clotting, and D-dimer. Creatine phosphokinase was 63 U/L (reference < 167 U/L) and troponin I levels were not raised. Her only hematological abnormality was an elevated C-reactive protein (CRP) at 60.2 mg/L (reference < 5 mg/L). Magnetic resonance imaging (MRI) scan showed signal hyperintensity involving T7 vertebral body, surrounding an enlarged SN. Patient was given oral nonsteroidal anti-inflammatory drugs, opioid analgesia, and gradually mobilized. After 3 days, the pain had sufficiently subsided and CRP was 17.8 mg/L. Follow-up MRI scan showed some reduction in the T2 hyperintensity and size of the intraosseous herniation. Patient gradually returned to full activities and had no recurrence of symptoms. MRI scan 8 months after the initial scan showed almost complete resolution of the T2 hyperintensity and pan-vertebral marrow edema. CONCLUSION: Symptomatic SN should be part of the differential diagnosis of unexplained thoracolumbar pain. Modality of choice for diagnosis would be MRI. Once diagnosed, several treatment options are available with the most likely being spontaneous resolution of symptoms and bone healing within a few months. The conservative approach is recommended when the symptoms can be medically well controlled.

Essential lordosis revisited.

AIMS: Significant correction of an adolescent idiopathic scoliosis in the coronal plane through a posterior approach is associated with hypokyphosis. Factors such as the magnitude of the preoperative coronal curve, the use of hooks, number of levels fused, preoperative kyphosis, screw density, and rod type have all been implicated. Maintaining the normal thoracic kyphosis is important as hypokyphosis is associated with proximal junctional failure (PJF) and early onset degeneration of the spine. The aim of this study was to determine if coronal correction per se was the most relevant factor in generating hypokyphosis. METHODS: A total of 95 patients (87% female) with a median age of 14 years were included in our study. Pre- and postoperative radiographs were measured and the operative data including upper instrumented vertebra (UIV), lower instrumented vertebra (LIV), metal density, and thoracic flexibility noted. Further analysis of the post-surgical coronal outcome (group 1 < 60% correction and group 2 ≥ 60%) were studied for their association with the postoperative kyphosis in the sagittal plane using univariate and multivariate logistic regression. RESULTS: Of the 95 patients, 71.6% (68) had a thoracic correction of > 60%. Most (97.8%) had metal density < 80%, while thoracic flexibility > 50% was found in 30.5% (29). Preoperative hypokyphosis (< 20°) was present in 25.3%. A postoperative thoracic hypokyphosis was four times more likely to occur in patients with thoracic correction ≥ 60% (odds ratio (OR) 4.08; p = 0.005), after adjusting for confounding variables. This association was not affected by metal density, thoracic flexibility, LIV, UIV, age, or sex. CONCLUSION: Our study supports the 'essential lordosis' hypothesis of Roaf and Dickson, i.e. with a greater ability to translate the apical vertebra towards the midline, there is a commensurate lengthening of the anterior column due to the vertebral wedging. Cite this article: Bone Joint J 2020;102-B(4):513-518.

Intrathecal baclofen pumps do not accelerate progression of scoliosis in quadriplegic spastic cerebral palsy.

PURPOSE: To compare scoliosis progression in quadriplegic spastic cerebral palsy with and without intrathecal baclofen (ITB) pumps. METHODS: A retrospective matched cohort study was conducted. Patients with quadriplegic spastic cerebral palsy, GMFCS level 5, treated with ITB pumps with follow-up >1 year were matched to comparable cases by age and baseline Cobb angle without ITB pumps. Annual and peak coronal curve progression, pelvic obliquity progression and need for spinal fusion were compared. RESULTS: ITB group: 25 patients (9 female), mean age at pump insertion 9.4 and Risser 0.9. Initial Cobb angle 25.6° and pelvic tilt 3.2°. Follow-up 4.3 (1.0-7.8) years. Cobb angle at follow-up 76.1° and pelvic tilt 18.9°. Non-ITB group: 25 patients (14 female), mean age at baseline 9.2 and Risser 1.0. Initial Cobb angle 29.7° and pelvic tilt 7.1°. Follow-up 3.5 (1.0-7.5) years. Cobb angle at follow-up 69.1° and pelvic tilt 21.0°. The two groups were statistically similar for baseline age, Cobb angle and Risser grade. Mean curve progression was 13.6°/year for the ITB group vs 12.6°/year for the non-ITB group (p = 0.39). Peak curve progression was similar between the groups. Pelvic tilt progression was comparable; ITB group 4.5°/year vs non-ITB 4.6°/year (p = 0.97). During follow-up 5 patients in the ITB group and 9 in the non-ITB group required spinal fusion surgery for curve progression (p = 0.35). CONCLUSIONS: Patients with quadriplegic spastic cerebral palsy with and without ITB pumps showed significant curve progression over time. ITB pumps do not appear to alter the natural history of curve progression in this population.

The effect of metal density in thoracic adolescent idiopathic scoliosis.

PURPOSE: Determine impact of metal density on curve correction and costs in thoracic adolescent idiopathic scoliosis (AIS). Ascertain if increased metal density is required for larger or stiffer curves. METHODS: Multicentre retrospective case series of patients with Lenke 1-2 AIS treated with single-stage posterior only surgery using a standardized surgical technique; constructs using >80 % screws with variable metal density. All cases had >2-year follow up. Outcomes measures included coronal and sagittal radiographic outcomes, metal density (number of instrumented pedicles vs total available), fusion length and cost. RESULTS: 106 cases included 94 female. 78 Lenke 1. Mean age 14 years (9-26). Mean main thoracic (MT) Cobb angle 63° corrected to 22° (66 %). No significant correlations were present between metal density and: (a) coronal curve correction rates of the MT (r = 0.13, p = 0.19); (b) lumbar curve frontal correction (r = -0.15, p = 0.12); (c) correction index in MT curve (r = -0.10, p = 0.32); and (d) correction index in lumbar curve (r = 0.11, p = 0.28). Metal density was not correlated with change in thoracic kyphosis (r = 0.22, p = 0.04) or lumbosacral lordosis (r = 0.27, p = 0.01). Longer fusions were associated with greater loss of thoracic kyphosis (r = -0.31, p = 0.003). Groups differing by preoperative curve size and stiffness had comparable corrections with similar metal density. The pedicle screw cost represented 21-29 % of overall cost of inpatient treatment depending on metal density. CONCLUSIONS: Metal density affects cost but not the coronal and sagittal correction of thoracic AIS. Neither larger nor stiffer curves necessitate high metal density.

Does transcranial stimulation for motor evoked potentials (TcMEP) worsen seizures in epileptic patients following spinal deformity surgery?

PURPOSE: To investigate the effect of Transcranial Motor Evoked Potentials (TcMEP) in increasing the severity or frequency of post-operative seizures in patients undergoing deformity corrective spine surgery with a known history of seizures pre-operatively. METHODS: The information on all patients with history of epilepsy/seizures who underwent spinal TcMEP cord monitoring for deformity correction surgery was retrospectively collected through a review of the hospital notes. The benefits of TcMEP in the early detection of potential cord ischemia were deemed by the operating surgeon to outweigh the increased risks of seizures, tongue biting, etc. Data on age, gender, pre-operative diagnosis, curve type, intra-operative monitoring alerts, duration of hospital stay, and post-operative in-hospital seizures were collected. Additionally, the patients were contacted following discharge and data on any change in the frequency of the seizures or an alteration in seizure-related medication post-operatively was also collected. RESULTS: The records of 449 consecutively monitored patients were reviewed and 12 (2.7 %) patients with a history of seizures pre-operatively were identified. The mean age was 23 (9-59) years, 7 females, 11 scoliosis corrections (4 neuromuscular, 1 degenerative, 6 idiopathic adolescent), and one sagittal balance correction surgery. Intra-operatively, all patients had TcMEP monitoring, were catheterised, and had no neuromonitoring alerts or record of tongue biting or laceration. Post-operatively, the mean hospital stay was 12 (4-25) days with no recorded seizures. At a mean of 23 (12-49) months post-discharge, none of the patients reported a worsening of seizures (pattern or frequency) or required an alteration in the seizure-related medications. CONCLUSION: TcMEP does not appear to trigger intra-operative or post-operative seizures and is not associated with deterioration in the seizure control of patients suffering seizures pre-operatively.

Anterior or posterior surgery for right thoracic adolescent idiopathic scoliosis (AIS)? A prospective cohorts' comparison using radiologic and functional outcomes.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: Prospectively compare patient-reported as well as clinical and radiologic outcomes after anterior or posterior surgery for right thoracic adolescent idiopathic scoliosis (AIS) in a single center by the same surgeons. SUMMARY OF BACKGROUND DATA: Anterior and posterior spinal instrumentation and arthrodesis are both well-established treatments of thoracic AIS. The majority of studies comparing the 2 approaches have focused on radiographic outcomes. There remains a paucity of prospectively gathered patient-reported outcomes comparing surgical approaches. METHODS: Forty-two consecutive patients with right thoracic AIS were treated in a single center by one of 2 surgeons with either anterior (n=18) or posterior (n=24) approaches and followed up for over 2 years. Radiographic, clinical, and patient-reported outcomes of the Modified Scoliosis Research Society Outcome Instrument were gathered and analyzed by an independent surgeon. RESULTS: Patients reported significant improvements in all areas of the Modified Scoliosis Research Society Outcome Instrument, especially pain and self-image domains. There were no significant differences in the degree of improvement in any domains between the groups. Posterior and anterior surgery corrected rib hump by 53% and 61%, respectively (P=0.4). The Main thoracic curve Cobb angle was corrected from 69 to 26 degrees (62%) by posterior surgery and 61 to 23 degrees (64%) by anterior surgery (P=0.6). Posterior surgery significantly reduced kyphosis and lumbosacral lordosis. Anterior surgery had no overall affect of sagittal alignment but seemed able to correct those hypokyphotic preoperatively. Complications differed and were largely approach-related--intrathoracic in anterior and wound-related in posterior surgery. CONCLUSIONS: Patients with right thoracic AIS of differing curve types but otherwise similar preoperatively demonstrated that anterior and posterior surgery are largely equivalent. Patient-reported outcomes are improved similarly by either approach. Both offer excellent radiographic and trunk deformity correction. Differences in the effect of sagittal alignment, operative time, and complications should be considered when selecting approach.

Do vertebral derotation techniques offer better outcomes compared to traditional methods in the surgical treatment of adolescent idiopathic scoliosis?

PURPOSE: In recent years, authors have described novel derotation techniques for surgery in adolescent idiopathic scoliosis. These methods include direct vertebral body derotation (DVD) and vertebral coplanar alignment (VCA). By improved derotation it is hoped that there is further reduction in rib hump prominence and corresponding improvement in patients' quality of life. This paper aims to evaluate studies reporting outcomes from DVD and VCA techniques to assess if these methods lead to superior radiographic vertebral derotation, rib hump correction on surface measurements or patient-reported outcomes compared to traditional derotation manoeuvres using similar instrumentation. METHOD: Literature review. RESULTS: Fifteen reports were identified. Most comparative studies represent class three or four data. DVD and VCA techniques have been shown to reduce apical vertebral rotation by 37-63 %. Few studies compare DVD/VCA techniques with traditional methods. Most DVD/VCA reports with pedicle screw instrumentation have reported superior radiographic derotation on CT compared with conventional techniques. Despite this the majority of studies have found similar corrections of rib hump measurements between DVD/VCA techniques and cantilever or global derotation methods. There is no evidence that DVD/VCA techniques allow greater correction of significant rib hump deformity without an adjuvant thoracoplasty. No studies to date have used patient-reported outcomes prospectively or demonstrated clinically meaningful differences retrospectively between DVD/VCA and conventional techniques. CONCLUSIONS: There is little evidence to recommend the widespread adoption of DVD/VCA techniques. Whilst there is some weak evidence to suggest that novel techniques may improve radiographic measures, there is little to suggest that they offer patients improved correction of clinical rib hump or quality of life compared to established techniques. Further well-designed prospective studies are needed in this area.

Double-curve synchronous derotation with convex correction: a new corrective technique for adolescent idiopathic scoliosis with double curves.

STUDY DESIGN: Report of a new technique. OBJECTIVE: We describe a new technique of double-curve synchronous derotation with convex correction for double-major adolescent idiopathic scoliosis (AIS) and is highlighted through illustrative cases. SUMMARY OF BACKGROUND DATA: Rotational deformity is a significant component of scoliosis, which causes a secondary rib hump, and adversely affects patients' psychological and social well-being, and long-term functional results. For AIS, direct vertebral rotation is confirmed as a better and effective method for apical rotational correction and rib hump improvement than rod rotation technique, avoiding the need for an adjuvant thoracoplasty. However, this technique is mainly applied to Lenke I type thoracic curves with derotation of the main curve. There are no reports applying this technique in double-major scoliosis. OPERATIVE TECHNIQUE: With the patient lying prone, a standard posterior incision exposure and segmental screws placement was performed, 2 vertebral column manipulator devices were installed on the apical region of both curves, then both curves were synchronously derotated and following convex correction at both the curves, the concave rods were secured in situ. RESULTS: There were 11 double-curve cases divided into 3 groups: double-curve derotation group (A group, 3 cases), single-curve derotation group (B group, 4 cases), and rod derotation group (C group, 4 cases); all cases had minimum 2-year follow-up. Three illustrative cases corrected by double-curve synchronous derotation with convex correction are presented with better apical rotational and correction in thoracic and lumbar curves than single-curve derotation and rod derotation cases. The mean apical derotational corrective rates were 95.3%, 46.7%, and 38.8% in the lumbar curve, 66%, -35.1%, and -38.9% in thoracic curve. The 3-dimensional correction was maintained at a minimum 2-year follow-up. CONCLUSIONS: Double-curve synchronous derotation with convex correction is a safe and effective technique for rotational and coronal correction in AIS with double curves, which can avoid apical rotation aggravation in minor curve induced by major curve derotaion.

Comparison of untreated adolescent idiopathic scoliosis with normal controls: a review and statistical analysis of the literature.

STUDY DESIGN: Review and statistical analysis of studies evaluating health-related quality of life (HRQOL) in adolescents with untreated adolescent idiopathic scoliosis (AIS) using Scoliosis Research Society (SRS) outcomes. OBJECTIVE: To apply normative values and minimum clinical important differences for the SRS-22r to the literature. Identify whether the HRQOL of adolescents with untreated AIS differs from unaffected peers and whether any differences are clinically relevant. SUMMARY OF BACKGROUND DATA: The effect of untreated AIS on adolescent HRQOL is uncertain. The lack of published normative values and minimum clinical important difference for the SRS-22r has so far hindered our interpretation of previous studies. The publication of this background data allows these studies to be re-examined. METHODS: Using suitable inclusion criteria, a literature search identified studies examining HRQOL in untreated adolescents with AIS. Each cohort was analyzed individually. Statistically significant differences were identified by using 95% confidence intervals for the difference in SRS-22r domain mean scores between the cohorts with AIS and the published data for unaffected adolescents. If the lower bound of the confidence interval was greater than the minimum clinical important difference, the difference was considered clinically significant. RESULTS: Of the 21 included patient cohorts, 81% reported statistically worse pain than those unaffected. Yet in only 5% of cohorts was this difference clinically important. Of the 11 cohorts included examining patient self-image, 91% reported statistically worse scores than those unaffected. In 73% of cohorts this difference was clinically significant. Affected cohorts tended to score well in function/activity and mental health domains and differences from those unaffected rarely reached clinically significant values. CONCLUSION: Pain and self-image tend to be statistically lower among cohorts with AIS than those unaffected. The literature to date suggests that it is only self-image which consistently differs clinically. This should be considered when assessing the possible benefits of surgery.

What is the effect of surgery on the quality of life of the adolescent with adolescent idiopathic scoliosis? A review and statistical analysis of the literature.

STUDY DESIGN: Review and statistical analysis of studies evaluating the effect of surgery on the health-related quality of life of adolescents with adolescent idiopathic scoliosis, using Scoliosis Research Society (SRS) outcomes. OBJECTIVE: Apply published minimum clinical important differences (MCID) values for the SRS22r questionnaire to the literature to identify what areas of health-related quality of life are consistently affected by surgery and whether changes are clinically meaningful. SUMMARY OF BACKGROUND DATA: The interpretation of published studies using the SRS outcomes has been limited by the lack of MCID values for the questionnaire domains. The recent publication of these data allows the clinical importance of any changes in these studies to be examined for the first time. METHODS: A literature search was undertaken to locate suitable studies that were then analyzed. Statistically significant differences from baseline to 2 years postoperatively were ascertained by narratively reporting the analyses within included studies. When possible, clinically significant changes were assessed using 95% confidence intervals for the change in mean domain score. If the lower bound of the confidence intervals for the change exceeded the MCID for that domain, the change was considered clinically significant. RESULTS: The numbers of cohorts available for the different analyses varied (5-16). Eighty-one percent and 94% of included cohorts experienced statistically significant improvements in pain and self-image domains. In terms of clinical significance, it was only self-image that regularly improved by more than MCID, doing so in 4 of 5 included cohorts (80%) compared with 1 of 12 cohorts (8%) for pain. No clinically relevant changes occurred in mental health or activity domains. CONCLUSION: Evidence suggests that surgery can lead to clinically important improvement in patient self-image. Surgeons and patients should be aware of the limited evidence for improvements in domains other than self-image after surgery. Surgical decision-making will also be influenced by the natural history of adolescent idiopathic scoliosis.

Upper arm length model suggests transient bilateral asymmetry is associated with right thoracic adolescent idiopathic scoliosis (RT-AIS) with implications for pathogenesis and estimation of linear skeletal overgrowth.

INTRODUCTION: In girls with adolescent idiopathic scoliosis (AIS) the finding of abnormal extra-spinal bilateral skeletal length asymmetries in upper limbs, periapical ribs, and ilia begs the question whether these bilateral asymmetries are connected in some way with pathogenesis. MATERIAL AND METHODS: We investigated upper arm length (UAL) asymmetries in two groups of right-handed girls aged 11-18 years with right thoracic adolescent idiopathic scoliosis (RT-AIS, n=95) from preoperative and screening referrals (mean Cobb angle 46°) and healthy controls (n=240). Right and left UAL were measured with a Harpenden anthropometer of the Holtain equipment, Asymmetry was calculated as UAL difference, right minus left, in mm. Repeatability of the measurements was assessed as technical error of the measurement and coefficient of reliability. RESULTS: In girls with RT-AIS, UAL asymmetry was greater than in healthy girls, regressed negatively with age and correlated significantly with Cobb angle and apical vertebral rotation. In healthy girls, UAL asymmetry was unrelated to age. Plotted against years after estimated menarcheal age, UAL asymmetry decreased significantly for girls with RT-AIS but not for healthy girls. DISCUSSION AND CONCLUSIONS: The apparent transience of the abnormal UAL asymmetry suggests it is not secondary to spinal deformity but pathogenetically associated with it. We suggest two hypotheses to account for these changes: (1) a transient asymmetry process with growth velocity; and (2) in the light of subsequent research, early skeletal overgrowth with catch-down growth affecting right but not left upper arm. The relation of the upper arm length asymmetry to the increased length of periapical left ribs reported for RT-AIS is unknown. Right upper arm length may provide a more simple model than arm span, for estimating linear skeletal overgrowth of girls with RT-AIS.

Fixed lumbar apical vertebral rotation predicts spinal decompensation in Lenke type 3C adolescent idiopathic scoliosis after selective posterior thoracic correction and fusion.

Retrospective radiographic review of surgically treated double major curves (Lenke type 3C) in adolescent idiopathic scoliosis. To evaluate the role of selective posterior thoracic correction and fusion in double major curves with third generation instrumentation and to identify preoperative radiographic parameters that predict postoperative coronal spinal decompensation. Traditionally the surgical treatment of double major curves consists of fusion of both the thoracic and the lumbar curve. Few attempt to perform selective thoracic fusion in this curve pattern because of the potential to create spinal imbalance. Thirty-six patients with Lenke type 3C curves underwent a selective posterior thoracic correction and fusion with either Cotrel-Dubousset instrumentation or the Universal Spine System. Radiographs were evaluated to assess coronal and sagittal balance, curve flexibility, and curve correction at a minimum follow up of 2 years. Postoperative coronal spinal decompensation was investigated with respect to preoperative radiographic parameters on standing anteroposterior (AP), standing lateral radiographs, thoracic and lumbar supine side-bending radiographs. Coronal spinal decompensation was defined as plumbline deviation of C7 of more than 2 cm with respect to the centre sacral vertical line (CSVL) within 2 years of surgery. Twenty-six patients (72%) showed satisfactory frontal plane alignment patients (28%) showed coronal spinal decompensation. Significant group differences, however, were identified for lumbar apical vertebral rotation, measured according to Perdriolle (La scoliose. Son êtude tridimensionnelle. Maloine, Paris, pp 179, 1979) (A 16 degrees , B 22 degrees , P = 0.02), percentage correction (derotation) of lumbar apical vertebrae in lumbar supine side-bending films in comparison to standing AP radiographs (A 49%, B 27%, P = 0.002) and thoracic curve flexibility (A 43%, B 25%, P = 0.03). High correlation was noted between postoperative decompensation and derotation of lumbar apical vertebrae in pre-operative lumbar supine side-bending films with a critical value of 40% (Pearson correlation coefficient; P = 0.62, P < 0.001). Ten of 36 patients (28%) with Lenke type 3C adolescent idiopathic scoliosis showed coronal spinal decompensation of more than 2 cm after selective posterior thoracic correction and fusion. Lumbar apical vertebral derotation of less than 40% provided the radiographic prediction of postoperative coronal spinal imbalance. We advise close scrutiny of the transverse plane in the lumbar supine bending film when planning surgical strategy.

Clinical outcome of symptomatic unilateral stress injuries of the lumbar pars interarticularis.

STUDY DESIGN: A prospective case-series study. OBJECTIVE: To evaluate the results of nonoperative and operative treatment of symptomatic unilateral lumbar pars stress injuries or spondylolysis. SUMMARY OF BACKGROUND DATA: Most patients become asymptomatic following nonoperative treatment for unilateral lumbar pars stress injuries or spondylolysis. Surgery, however, is indicated when symptoms persist beyond a reasonable time affecting the quality of life in young patients, particularly the athletic population. METHODS: We treated 42 patients (31 male, 11 female) with unilateral lumbar pars stress injuries or spondylolysis. Thirty-two patients were actively involved in sports at various levels. Patients with a positive stress reaction on single photon emission computerized tomography imaging underwent a strict protocol of activity restriction, bracing, and physical therapy for 6 months. At the end of 6 months, patients who remained symptomatic underwent a computed tomography (CT) scan to confirm the persistence of a spondylolysis. Eight patients subsequently underwent a direct repair of the defect using the modified Buck's Technique. Baseline Oswestry Disability Index (ODI) and Short-Form-36 (SF-36) scores were compared with 2-year ODI and SF-36 scores for all patients. RESULTS: Eight of nine fast bowlers in cricket were right-handed. The spondylolytic defect appeared on the left side of their lumbar spine. In the nonoperated group, the mean pretreatment ODI was 36 (SD = 10.5), improving to 6.2 (SD = 8.2) at 2 years. In SF-36 scores, the mean score for physical component of health (PCS) improved from 30.7 (SD = 3.2) to 53.5 (SD = 6.5) (P < 0.001), and the mean score for the mental component of health (MCS) improved from 39 (SD = 4.1) and 56.5 (SD = 3.9) (P < 0.001) at 2 years. Twenty of 32 patients resumed their sporting career within 6 months of onset of treatment, and a further 4 of 32 patients returned to sports within 1 year. The 8 patients who remained symptomatic at 6 months underwent a unilateral modified Buck's repair. The most common level of repair was L5 (n = 5). One patient with spina bifida and a right-sided L5 pars defect remained symptomatic following direct repair. The mean preoperative ODI was 39.4 (SD = 3.6), improving to 6.4 (SD = 5.2) at the latest follow-up. The mean score of PCS (SF-36) improved from 29.6 (SD = 4.4) to 49.2 (SD = 6.2) (P < 0.001), and the mean score of MCS (SF-36) improved from 38.7 (SD = 1.9) to 54.5 (SD = 6.4) (P < 0.001). CONCLUSIONS: The increased incidence of the unilateral lumbar pars stress injuries or frank defect on the contralateral side in a throwing sports, e.g., cricket (fast bowling), may be related to the hand dominance of the individual. Nonoperative treatment for patients with a unilateral lumbar pars stress injuries or spondylolysis resulted in a high rate of success, with 81% (34/42) of patients avoiding surgery. If symptoms persist beyond a reasonable period, i.e., 6 months, and reverse gantry CT scan confirms a nonhealing defect of the pars interarticularis, one may consider a unilateral direct repair of the defect with good functional outcome. Direct repair in patients with spina bifida at the same lumbar level as the unilateral defect may be complicated by nonunion.

Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome.

STUDY DESIGN: Retrospective cohort study with prospective clinical follow-up. OBJECTIVE: To determine the factors that influence outcome after surgery for cauda equina syndrome (CES). SUMMARY OF BACKGROUND DATA: CES is a rare but serious consequence of lumbar disc prolapse and can have devastating long-lasting neurologic consequences. The timing of surgical decompression remains controversial. METHODS: Fifty-six patients with evidence of a sphincteric disturbance who underwent urgent surgery were identified and invited to follow-up. The outcome measures comprised history and examination and several validated self-assessment questionnaires. RESULTS: Forty-two patients (78%) attended with a mean follow-up of 60 months (range, 25-114 months). Mean age at onset was 41 years (range, 24-67 years) with 23 males and 19 females. Twenty-six patients were operated on within 48 hours of onset of sphincteric symptoms; 5 of these were within 24 hours. Acute onset of sphincteric symptoms and the time to operation did not influence the outcomes. Leg weakness at onset persisted in a significant number of patients at follow-up (P < 0.005). Urinary disturbance at presentation did not affect the outcomes. At follow-up, significantly more females had urinary incontinence (P < 0.005). Bowel dysfunction at presentation was associated with sexual problems at follow-up (P < 0.005). The 13 patients who failed their post operative trial without catheter had worse outcomes. The SF-36 scores at follow-up were reduced compared with age-matched controls in the population. The mean ODI was 29, Low Back Outcome Score 42, and VAS 4.5. The time elapsed from operation to follow-up was not found to influence the outcomes. CONCLUSIONS: In our series, the symptom duration before operation and the speed of onset do not affect the outcome more than 2 years after surgery. Based on the SF-36, ODI, and Low Back Outcome Scores, patients who have had CES do not return to a normal status.

A prospective, randomised controlled trial of femoral ring allograft versus a titanium cage in circumferential lumbar spinal fusion with minimum 2-year clinical results.

The literature reports on the safety and efficacy of titanium cages (TCs) with additional posterior fixation for anterior lumbar interbody fusion. However, these papers are limited to prospective cohort studies. The introduction of TCs for spinal fusion has resulted in increased costs, without evidence of superiority over the established practice. There are currently no prospective controlled trials comparing TCs to femoral ring allografts (FRAs) for circumferential fusion in the literature. In this prospective, randomised controlled trial, our objective was to compare the clinical outcome following the use of FRA (current practice) to the use of TC in circumferential lumbar spinal fusion. Full ethical committee approval and institutional research and development departmental approval were obtained. Power calculations estimated a total of 80 patients (40 in each arm) would be required to detect clinically relevant differences in functional outcome. Eighty-three patients were recruited for the study fulfilling strict entry requirements (>6 months chronic discogenic low back pain, failure of conservative treatment, one- or two-level discographically proven discogenic low back pain). The patients completed the Oswestry Disability Index (ODI), Visual Analogue Score (VAS) for back and leg pain and the Short-Form 36 (SF-36) preoperatively and also postoperatively at 6, 12 and 24 months, respectively. The results were available for all the 83 patients with a mean follow-up of 28 months (range 24-75 months). Five patients were excluded on the basis of technical infringements (unable to insert TC in four patients and FRA in one patient due to the narrowing of the disc space). From the remaining 78 patients randomised, 37 received the FRA and 41 received the TC. Posterior stabilisation was achieved with translaminar or pedicle screws. Baseline demographic data (age, sex, smoking history, number of operated levels and preoperative outcome measures) showed no statistical difference between groups (p<0.05) other than for the vitality domain of the SF-36. For patients who received the FRA, mean VAS (back pain) improved by 2.0 points (p<0.01), mean ODI improved by 15 points (p=<0.01) and mean SF-36 scores improved by >11 points in all domains (p<0.03) except that of general health and emotional role. For patients who received the TC, mean VAS improved by 1.1 points (p=0.004), mean ODI improved by 6 points (p=0.01) and SF-36 improved significantly in only two of the eight domains (bodily pain and physical function). Revision procedures and complications were similar in both groups. In conclusion, this prospective, randomised controlled clinical trial shows the use of FRA in circumferential lumbar fusion to be associated with superior clinical outcomes when compared to those observed following the use of TCs. The use of TCs for circumferential lumbar spinal fusion is not justified on the basis of inferior clinical outcome and the tenfold increase in cost.

"Does size matter?"A comparison of balloon-assisted less-invasive vs conventional retroperitoneal approach for anterior lumbar interbody fusion.

This is a case-series comparison of two approaches to anterior lumbar interbody fusion. A conventional open approach (COA) was compared with a balloon-assisted minimally invasive approach (BMI). Outcome measures included operating time, blood loss and complications. Secondary outcome measures included analgesia requirements, time to mobilization and inpatient stay. There were 17 females (7 COA, 10 BMI) and 18 males (9 COA and 9 BMI). Forty-five discs (21 COA, 24 BMI) in total were fused in 35 patients. There were significant differences (in favour of the BMI) in the overall operating time between the COA and the BMI, and the single level COA and the BMI. There was no inter-group difference in the PCA requirements either overall or between one or two-level operations. The less invasive approach did have a benefit in earlier mobilization of the single-level fusions.

A prospective randomized comparison of coralline hydroxyapatite with autograft in cervical interbody fusion.

STUDY DESIGN: A prospective randomized trial with independent clinical and radiographic outcome review of patients receiving either hydroxyapatite or tricortical iliac crest graft for cervical interbody fusion was conducted. OBJECTIVE: To determine whether coralline-derived hydroxyapatite is a suitable bone graft substitute in cervical interbody fusion. SUMMARY OF BACKGROUND DATA: Tricortical iliac crest bone is the "gold standard" graft material for cervical interbody fusion. Various bone substitutes have been used for this procedure to avoid potential donor site morbidity. ProOsteon 200 is a coralline-derived hydroxyapatite product, the use of which remains unclear for cervical interbody fusion. METHODS: In this study, 29 patients undergoing anterior cervical fusion and plating were randomized to receive either ProOsteon 200 or iliac crest grafts. The SF-36 and Oswestry Disability Index were used to measure clinical outcome. Postoperative radiographs were analyzed for graft fragmentation, loss of height, angular alignment, and hardware failure to assess structural integrity of the graft material. Plain radiographs and computed tomography scans were used to evaluate fusion. RESULTS: Both the ProOsteon 200 and iliac crest groups demonstrated significant improvement in clinical outcome scores. There was no significant difference in clinical outcome or fusion rates between the two groups. Graft fragmentation occurred in 89% of the hydroxyapatite grafts and 11% of the autografts (P = 0.001). Significant graft settling occurred in 50% of the hydroxyapatite grafts, as compared with 11% of the autografts (P = 0. 009). One patient in the ProOsteon 200 group required revision surgery for graft failure. CONCLUSIONS: ProOsteon 200 does not possess adequate structural integrity to resist axial loading and maintain disc height or segmental lordosis during cervical interbody fusion.