Pathogenesis of adolescent idiopathic scoliosis in girls - a double neuro-osseous theory involving disharmony between two nervous systems, somatic and autonomic expressed in the spine and trunk: possible dependency on sympathetic nervous system and hormones with implications for medical therapy

Anthropometric data from three groups of adolescent girls - preoperative adolescent idiopathic scoliosis (AIS), screened for scoliosis and normals were analysed by comparing skeletal data between higher and lower body mass index subsets. Unexpected findings for each of skeletal maturation, asymmetries and overgrowth are not explained by prevailing theories of AIS pathogenesis. A speculative pathogenetic theory for girls is formulated after surveying evidence including: (1) the thoracospinal concept for right thoracic AIS in girls; (2) the new neuroskeletal biology relating the sympathetic nervous system to bone formation/resorption and bone growth; (3) white adipose tissue storing triglycerides and the adiposity hormone leptin which functions as satiety hormone and sentinel of energy balance to the hypothalamus for long-term adiposity; and (4) central leptin resistance in obesity and possibly in healthy females. The new theory states that AIS in girls results from developmental disharmony expressed in spine and trunk between autonomic and somatic nervous systems. The autonomic component of this double neuro-osseous theory for AIS pathogenesis in girls involves selectively increased sensitivity of the hypothalamus to circulating leptin (genetically-determined up-regulation possibly involving inhibitory or sensitizing intracellular molecules, such as SOC3, PTP-1B and SH2B1 respectively), with asymmetry as an adverse response (hormesis); this asymmetry is routed bilaterally via the sympathetic nervous system to the growing axial skeleton where it may initiate the scoliosis deformity (leptin-hypothalamic-sympathetic nervous system concept = LHS concept). In some younger preoperative AIS girls, the hypothalamic up-regulation to circulating leptin also involves the somatotropic (growth hormone/IGF) axis which exaggerates the sympathetically-induced asymmetric skeletal effects and contributes to curve progression, a concept with therapeutic implications. In the somatic nervous system, dysfunction of a postural mechanism involving the CNS body schema fails to control, or may induce, the spinal deformity of AIS in girls (escalator concept). Biomechanical factors affecting ribs and/or vertebrae and spinal cord during growth may localize AIS to the thoracic spine and contribute to sagittal spinal shape alterations. The developmental disharmony in spine and trunk is compounded by any osteopenia, biomechanical spinal growth modulation, disc degeneration and platelet calmodulin dysfunction. Methods for testing the theory are outlined. Implications are discussed for neuroendocrine dysfunctions, osteopontin, sympathoactivation, medical therapy, Rett and Prader-Willi syndromes, infantile idiopathic scoliosis, and human evolution. AIS pathogenesis in girls is predicated on two putative normal mechanisms involved in trunk growth, each acquired in evolution and unique to humans

A prospective study of the role of bladder scanning and post-void residual volume measurement in improving diagnostic accuracy of cauda equina syndrome

Aims: Diagnosis of cauda equina syndrome (CES) remains difficult; clinical assessment has low accuracy in reliably predicting MRI compression of the cauda equina (CE). This prospective study tests the usefulness of ultrasound bladder scans as an adjunct for diagnosing CES.Methods: A total of 260 patients with suspected CES were referred to a tertiary spinal unit over a 16-month period. All were assessed by Board-eligible spinal surgeons and had transabdominal ultrasound bladder scans for pre- and post-voiding residual (PVR) volume measurements before lumbosacral MRI.Results: The study confirms the low predictive value of \u27red flag\u27 symptoms and signs. Of note \u27bilateral sciatica\u27 had a sensitivity of 32.4%, and a positive predictive value (PPV) of only 17.2%, and negative predictive value (NPV) 88.3%. Use of a PVR volume of ≥ 200 ml was a demonstrably more accurate test for predicting cauda equina compression on subsequent MRI (p \u3c 0.001). The PVR sensitivity was 94.1%, specificity 66.8%, PPV 29.9% and NPV 98.7%. The PVR allowed risk-stratification with 13% patients deemed \u27low-risk\u27 of CES. They had non-urgent MRI scans. None of the latter scans showed any cauda equina compression (p \u3c 0.006) or individuals developed subsequent CES in the intervening period. There were considerable cost-savings associated with the above strategy.Conclusion: This is the largest reported prospective evaluation of suspected CES. Use of the PVR volume ≥ 200 ml was considerably more accurate in predicting CES. It is a useful adjunct to conventional clinical assessment and allows risk-stratification in managing suspected CES. If adopted widely it is less likely incomplete CES would be missed. Cite this article: Bone Joint J 2020;102-B(6):677-682

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

Long-term outcome after surgical treatment of Scheuermann\u27s 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 \u3c 0.0001) and 30.7 ± 11.7 and 6.4 ± 5.7, respectively, in group 2 (p \u3c 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 \u3c 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 \u3c 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 \u3c 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 \u3c 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 \u3c 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

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°, B 22°, 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

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 original publication can be found at www.springerlink.comThe 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 (p11 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.Patrick J. McKenna, Brian J. C. Freeman, Robert C. Mulholland, Michael P. Grevitt, John K. Webb and S. H. Mehdia

Pain regulation and health-related quality of life after thoracolumbar fractures of the spine

Fractures of the thoracolumbar spine rank among the severest injuries of the human skeleton. Especially in younger patients they often result from high-energy accidents. Recently, a shift in paradigm towards more aggressive treatment strategies including anterior procedures could be observed. However, so far only few data exist reflecting the quality of life (QoL) after such injuries. The aim of this study was to evaluate medium-term QoL and further to identify factors that influence the clinical outcome in patients with fractures of the thoracolumbar spine. Data of 906 patients who were treated during a 10-year period in our institution were evaluated retrospectively. Only patients with single-level traumatic injuries aged between 18 and 65 years without neurological deficits, concomitant injuries of other locations and internal comorbidities were included into the investigation (n = 204). Three different treatment groups (i.e. non-operative, dorsal and dorsoventral stabilisation) were compared to healthy controls as well as different pain populations. The QoL was assessed using established questionnaires (SF-36, HFAQ, VAS-Spinescore, PRQ, and PTSD). Sixty-five percent of the included patients (n = 133) were studied at an average follow-up of 5.3 ± 1.7 years after injury. All treatment groups revealed an identical gender and age distribution. More severe and unstable injuries were found in the surgical groups associated with higher treatment costs and a longer inability to work. Compared to healthy controls, QoL was compromised to the same extent in all groups. Furthermore, all patients treated in this study did significantly better than low back pain individuals with regard to QoL and pain regulation parameters. In our study, patients with thoracolumbar spine fractures showed a reduced QoL compared to healthy controls. Thus, patients do not seem to regain their former QoL. However, the level of discomfort was comparably low in all groups, even in patients with more severe injuries requiring extensive surgery. Overall, outcome and QoL after traumatic fractures of the thoracolumbar spine rather seem to be determined by the severity of injury than by pain regulation or other psychosocial factors which is likely the case in low back pain disorders