Changes in the Position of the Junctional Vertebrae After Posterior Spinal Fusion in Adolescent Idiopathic Scoliosis: Implication in Risk Assessment of Proximal Junctional Kyphosis Development.

BACKGROUND: The development of proximal junctional kyphosis (PJK) after posterior spinal fusion in adolescent idiopathic scoliosis is a major problem. Changes in the global sagittal parameters as they relate to PJK have been reported after surgery, however, the relationships between the changes in the upper-instrumented vertebra (UIV) during and after surgery as they relate to development of PJK have not been quantified. We hypothesize that the compensatory changes in the unfused segments of the spine over time are correlated with the surgically induced changes in the UIV position. METHODS: Sixty adolescent idiopathic scoliosis patients (with at least 1-year follow-up) who underwent posterior spinal surgery were included retrospectively. Global spinal parameters were calculated using 3-dimensional models of the spine, additional parameters [proximal junctional kyphosis angle (PJKA), cervical lordosis angle] were measured manually before surgery and at 3 postoperative follow-ups. The 3-dimensional position of the vertebral body centroids was calculated for T1, UIV, and lower-instrumented vertebra at all timepoints. The sagittal position of T1, UIV, and lower-instrumented vertebra were correlated to the cervical lordosis, PJKA, lumbar lordosis, and pelvic tilt. RESULTS: The position of T1 and UIV were significantly more anterior at first erect for patients who developed PJK. The posterior shift of UIV at the most recent follow-up as compared with the preoperative position was significant in both the PJK and non-PJK cohort. A larger anterior shift in UIV at first erect correlated with a larger T1 and UIV posterior shift at the most recent follow-up. At the most recent follow-up, a more posterior position of the UIV correlated with a larger angle of PJKA (P<0.05). CONCLUSION: Both a larger anterior shift of UIV between preoperative and first erect and a more posterior position of UIV at the most recent follow-up was correlated with a higher PJKA. A larger anterior shift in the position of the UIV after surgery was associated with a higher posterior shift of UIV at the last follow-up. The surgically induced changes in the UIV are an important parameter associated with the development of PJK. LEVEL OF EVIDENCE: Level IV.

The Clinical Utility of Flexion-extension Cervical Spine MRI in 22q11.2 Deletion Syndrome.

BACKGROUND: Our goal is to correlate the findings on flexion and extension radiographs with dynamic magnetic resonance imaging (MRI), and the clinical history, in a nonrandomly selected cohort of patients with 22q11.2 deletion syndrome (22q). METHODS: All patients with the 22q who had a dynamic MRI from January 2004 to March 2015 were included. We analyzed multiple radiographic measurements on both the dynamic plain films and the MRIs, and correlated these findings with a review of each patient's medical record. RESULTS: Multiple congenital anomalies were identified as noted in previous studies, and 61% of the patients had a failure of fusion of the anterior (n=2, 9%), posterior (n=2, 9%), or anterior and posterior arches (n=10, 43%). Quantitative measurements were impossible to report with certainty because of the upper cervical anomalies, and no cases of instability were identified using a qualitative assessment. We identified spinal cord encroachment (30%) and impingement (18%); however, none of the patients had any signal change in their spinal cord. None of these findings could be definitively correlated with any clinical symptoms. A single patient was diagnosed with a Chiari I malformation, while another had cerebellar ectopia. CONCLUSIONS: Although the upper cervical anomalies are extremely common in 22q, we did not identify cases of instability on dynamic plain radiographs and MRI. Although our findings do not support routine screening with flexion and extension MRI, this study may be required in patients with neurological symptoms and/or findings or abnormalities on dynamic plain radiographs. LEVEL OF EVIDENCE: Level III.

Prevalence and risk factors for neural axis anomalies in idiopathic scoliosis: a systematic review.

BACKGROUND: There is ongoing controversy about the routine use of magnetic resonance imaging (MRI) preoperatively in patients with presumed idiopathic scoliosis (IS). Routine MRI can help identify possible causes for the deformity and detect anomalies that could complicate deformity surgery. However, routine MRI increases health-care costs significantly and may reveal mild variations from normal findings without clinical relevance, which can still lead to anxiety and influence decision-making. PURPOSE: Given the necessity to make evidence-based decisions both in the light of quality of care and cost control, the aim of this review is to report the prevalence of neural axis anomalies in IS and to identify risk factors associated with these anomalies. STUDY DESIGN: A systematic review was carried out. METHODS: An electronic search of PubMed, Embase, Cochrane, and Cinahl until May 2017 was performed. Studies were assessed by two reviewers independently according to predetermined inclusion (MRI in presumed IS) and exclusion criteria (diagnosis other than IS). RESULTS: Fifty-one studies were included comprising 8,622 patients. In 981 patients, anomalies were found, resulting in an overall prevalence of 11.4%. The prevalence was 10.5%, 9.0%, and 14.2% when screening was performed of all IS patients, preoperative patients, or patients with presumed risk factors. The prevalence of a syrinx (3.7%), an Arnold-Chiari malformation (3.0%), or a combination of both (2.5%) was highest. Less frequent diagnoses included tethered cord (0.6%), an incidental malignancy (0.3%), and split cord malformations (0.2%). Risk factors for intraspinal anomalies included early-onset scoliosis, male gender, atypical curves, thoracic kyphosis, and abnormal neurologic findings such as reflexes and sensation. CONCLUSIONS: This systematic review shows that a significant number of patients have intraspinal anomalies on preoperative MRI in (presumed) IS. The prevalence of finding spinal axis abnormalities increases in preselected patient groups with specific risk factors.

Orthopaedic manifestations within the 22q11.2 Deletion syndrome: A systematic review.

The 22q11.2 Deletion Syndrome (22q11.2DS) is the most common microdeletion syndrome with an estimated prevalence of 1:4,000 live births. 22q11.2DS is known to have wide phenotypic variability, including orthopaedic manifestations. The purpose of this systematic review is to increase the awareness of orthopaedic manifestations associated with 22q11.2DS. This systematic review was performed according to the PRISMA Guidelines. Original epidemiological studies on the prevalence of orthopaedic manifestations within 22q11.2DS were systematically searched for in PubMed and EMBASE. The included articles were scored according to a risk-of-bias tool, a best-evidence synthesis was performed and the prevalence data was extracted. Sixty-nine published manuscripts described 58 orthopaedic manifestations in a total of 6,055 patients. The prevalence of at least one cervical or occipital anomaly is 90.5-100% (strong evidence). Fourteen studies (n = 2,264) revealed moderate evidence for a wide scoliosis prevalence of 0.6-60%. Two studies demonstrated that 5-6.4% of all 22q11.2DS patients required surgical scoliosis correction. Fifteen studies (n = 2,115) reported a 1.1-13.3% prevalence of clubfoot with moderate evidence. Other reported orthopaedic manifestations are patellar dislocation (10-20%), juvenile rheumatic arthritis (3.75%), impaired growth and skeletal anomalies like polydactyly (1.0-3.7%), syndactyly (11-11.8%), butterfly vertebrae (11.1%) and 13 ribs (2-19%). Orthopaedic findings are important manifestations of the 22q11.2DS, both in bringing patients to diagnostic attention and in requiring surveillance and appropriate intervention. Data on these manifestations are scattered and incomprehensive. Routinely screening for cervical anomalies, scoliosis, and upper and lower limb malformations is recommended in this vulnerable group of patients.

The Height-Width-Depth Ratios of the Intervertebral Discs and Vertebral Bodies in Adolescent Idiopathic Scoliosis vs Controls in a Chinese Population.

Adolescent idiopathic scoliosis (AIS) patients have been reported to be taller and more slender than normal controls, suggesting less mechanical stiffness of their trunk and spine. For assessment of mechanical stiffness, to our best knowledge this is the first to study height-width-depth relations at the level of the individual vertebra and disc in 3-D and to evaluate its relation with the Cobb angle severity. A unique series of high-resolution pre-operative computed tomographic (CT) scans of a total of 105 Chinese patients with moderate to severe AIS and 11 age-matched non-scoliotic controls were used for this study. It was found that some geometric relations differed between primary thoracic curves, secondary curves and normal controls at the individual affected vertebra and disc level. The scoliotic discs in the primary curves were relatively more slender (taller and thinner) than in secondary curves and as compared to controls. In the lumbar spinal area, the vertebral bodies were more slender in the primary as well as secondary AIS curves as compared to the controls. Therefore, if all material properties remain the same, our finding indicates that scoliotic spines may be mechanically less stiff than normal spines. No significant correlation between any of the measures and Cobb angle severity was found.

Upright, prone, and supine spinal morphology and alignment in adolescent idiopathic scoliosis.

BACKGROUND: Patients with adolescent idiopathic scoliosis (AIS) are usually investigated by serial imaging studies during the course of treatment, some imaging involves ionizing radiation, and the radiation doses are cumulative. Few studies have addressed the correlation of spinal deformity captured by these different imaging modalities, for which patient positioning are different. To the best of our knowledge, this is the first study to compare the coronal, axial, and sagittal morphology of the scoliotic spine in three different body positions (upright, prone, and supine) and between three different imaging modalities (X-ray, CT, and MRI). METHODS: Sixty-two AIS patients scheduled for scoliosis surgery, and having undergone standard pre-operative work-up, were included. This work-up included upright full-spine radiographs, supine bending radiographs, supine MRI, and prone CT as is the routine in one of our institutions. In all three positions, Cobb angles, thoracic kyphosis (TK), lumbar lordosis (LL), and vertebral rotation were determined. The relationship among three positions (upright X-ray, prone CT, and supine MRI) was investigated according to the Bland-Altman test, whereas the correlation was described by the intraclass correlation coefficient (ICC). RESULTS: Thoracic and lumbar Cobb angles correlated significantly between conventional radiographs (68° ± 15° and 44° ± 17°), prone CT (54° ± 15° and 33° ± 15°), and supine MRI (57° ± 14° and 35° ± 16°; ICC ≥0.96; P < 0.001). The thoracic and lumbar apical vertebral rotation showed a good correlation among three positions (upright, 22° ± 12° and 11° ± 13°; prone, 20° ± 9° and 8° ± 11°; supine, 16° ± 11° and 6° ± 14°; ICC ≥0.82; P < 0.001). The TK and LL correlated well among three different positions (TK 26° ± 11°, 22° ± 12°, and 17° ± 10°; P ≤ 0.004; LL 49° ± 12°, 45° ± 11°, and 44° ± 12°; P < 0.006; ICC 0.87 and 0.85). CONCLUSIONS: Although there is a generalized underestimation of morphological parameters of the scoliotic deformity in the supine and prone positions as compared to the upright position, a significant correlation of these parameters is still evident among different body positions by different imaging modalities. Findings of this study suggest that severity of scoliotic deformity in AIS patients can be largely represented by different imaging modalities despite the difference in body positioning.

Asymmetry of the Vertebral Body and Pedicles in the True Transverse Plane in Adolescent Idiopathic Scoliosis: A CT-Based Study.

STUDY DESIGN: Cross-sectional. OBJECTIVES: To quantify the asymmetry of the vertebral bodies and pedicles in the true transverse plane in adolescent idiopathic scoliosis (AIS) and to compare this with normal anatomy. SUMMARY OF BACKGROUND DATA: There is an ongoing debate about the existence and magnitude of the vertebral body and pedicle asymmetry in AIS and whether this is an expression of a primary growth disturbance, or secondary to asymmetrical loading. METHODS: Vertebral body asymmetry, defined as left-right overlap of the vertebral endplates (ie, 100%: perfect symmetry, 0%: complete asymmetry) was evaluated in the true transverse plane on CT scans of 77 AIS patients and 32 non-scoliotic controls. Additionally, the pedicle width, length, and angle and the length of the ideal screw trajectory were calculated. RESULTS: Scoliotic vertebrae were on average more asymmetric than controls (thoracic: AIS 96.0% vs. controls 96.4%; p = .005, lumbar: 95.8% vs. 97.2%; p < .001) and more pronounced around the thoracic apex (95.8%) than at the end vertebrae (96.3%; p = .031). In the thoracic apex; the concave pedicle was thinner (4.5 vs. 5.4 mm; p < .001) and longer (20.9 vs. 17.9 mm; p < .001), the length of the ideal screw trajectory was longer (43.0 vs. 37.3 mm; p < .001), and the transverse pedicle angle was greater (12.3° vs. 5.7°; p < .001) than the convex one. The axial rotation showed no clear correlation with the asymmetry. CONCLUSIONS: Even in non-scoliotic controls is a degree of vertebral body and pedicle asymmetry, but scoliotic vertebrae showed slightly more asymmetry, mostly around the thoracic apex. In contrast to the existing literature, there is no major asymmetry in the true transverse plane in AIS and no uniform relation between the axial rotation and vertebral asymmetry could be observed in these moderate to severe patients, suggesting that asymmetrical vertebral growth does not initiate rotation, but rather follows it as a secondary phenomenon. LEVEL OF EVIDENCE: Level 4.

Anterior Spinal Overgrowth Is the Result of the Scoliotic Mechanism and Is Located in the Disc.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To investigate the presence and magnitude of anterior spinal overgrowth in neuromuscular scoliosis and compare this with the same measurements in idiopathic scoliosis and healthy spines. SUMMARY OF BACKGROUND DATA: Anterior spinal overgrowth has been described as a potential driver for the onset and progression of adolescent idiopathic scoliosis (AIS). Whether this anterior overgrowth is specific for AIS or also present in nonidiopathic scoliosis has not been reported. METHODS: Supine computed tomography (CT) scans of thirty AIS patients (thoracic Cobb 21-81°), thirty neuromuscular (NM) scoliotic patients (thoracic Cobb 19-101°) and 30 nonscoliotic controls were used. The difference in length in per cents between the anterior and posterior side {[(ΔA-P)/P]*100%, abbreviated to A-P%} of each vertebral body and intervertebral disc, and between the anterior side of the spine and the spinal canal (A-C%) were determined. RESULTS: The A-P% of the thoracic curves did not differ between the AIS (+1.2 ±â€Š2.2%) and NM patients (+0.9 ±â€Š4.1%, P = 0.663), both did differ, however, from the same measurements in controls (-3.0 ±â€Š1.6%; P < 0.001) and correlated linearly with the Cobb angle (AIS r = 0.678, NM r = 0.687). Additional anterior length was caused by anterior elongation of the discs (AIS: A-P% disc +17.5 ±â€Š12.7% vs. A-P% body -2.5 ±â€Š2.6%; P < 0.001, NM: A-P% disc +19.1 ±â€Š18.0% vs. A-P% body -3.5 ±â€Š5.1%; P < 0.001). The A-C% T1-S1 in AIS and NM patients were similar (+7.9 ±â€Š1.8% and +8.7 ±â€Š4.0%, P = 0.273), but differed from the controls (+4.2 ±â€Š3.3%; P < 0.001). CONCLUSION: So called anterior overgrowth has been postulated as a possible cause for idiopathic scoliosis, but apparently it occurs in scoliosis with a known origin as well. This suggests that it is part of a more generalized scoliotic mechanism, rather than its cause. The fact that the intervertebral discs contribute more to this increased anterior length than the vertebral bodies suggests an adaptation to altered loading, rather than a primary growth disturbance. LEVEL OF EVIDENCE: 4.

Complete Remodeling After Conservative Treatment of a Severely Angulated Odontoid Fracture in a Patient With Osteogenesis Imperfecta: A Case Report.

STUDY DESIGN: Case report. OBJECTIVE: This is the first case report describing successful healing and remodeling of a traumatic odontoid fracture that was dislocated and severely angulated in a patient with osteogenesis imperfecta who was treated conservatively. SUMMARY OF BACKGROUND DATA: Osteogenesis imperfecta (OI) is a rare genetic disorder resulting in a low bone mass and bone fragility, predisposing these patients to fractures that often occur at a young age. Although any bone in the body may be involved, odontoid fractures are uncommon in this population. Because of a very high fusion rate, conservative management is accepted as a safe and efficient treatment of fractures of the odontoid in children. Several authors, however, recommend surgical treatment of patients who have failure of conservative treatment and have severe angulation or displacement of the odontoid. METHODS: A 5-year-old female, diagnosed with OI type I, presented with neck pain without any neurological deficits after falling out of a rocking chair backward, with her head landing first on the ground. Computed tomography confirmed a type III odontoid fracture without dislocation and she was initially treated with a rigid cervical orthosis. At 1 and 2 months of follow-up, progressive severe angulation of the odontoid was observed but conservative treatment was maintained as the space available for the spinal cord was sufficient and also considering the patient's history of OI. RESULTS: Eight months postinjury, she had no clinical symptoms and there was osseous healing of the fracture with remodeling of the odontoid to normal morphology. CONCLUSION: Even in patients with OI, severely angulated odontoid fractures might have the capacity for osseous healing and complete remodeling under conservative treatment. LEVEL OF EVIDENCE: 5.

Scoliosis in Children With Aicardi Syndrome.

BACKGROUND: Aicardi syndrome (ACS) is a rare neurodevelopmental disorder that was classically characterized by the triad of agenesis of corpus callosum, infantile spasms, and chorioretinal lacunae. As new cases emerge and new common phenotypic features are being described in subsequent reports, new modified diagnostic criteria have been proposed that now classify the observed costovertebral abnormalities as supporting diagnostic features. To our knowledge there are no previous studies focusing and describing the scoliosis observed in children with ACS. METHODS: We screened billing lists to identify patients seen in the Division of Orthopaedic Surgery at our institution with a diagnosis of ACS that were treated for scoliosis after 2001. A total of 5 patients were identified. Medical records and radiographs were retrospectively reviewed in all cases. In all of the patients the diagnosis of ACS had been confirmed through complete genetic evaluation and advanced imaging. RESULTS: The mean age when scoliosis was first noticed was 3.9±4.2 years (range, 0.5 to 10.5 y) with a mean Cobb angle of 22.5±6.7 degrees (range, 10 to 27 degrees). The mean age at the first orthopedic visit was 5.8±5.0 years (range, 1.5 to 13 y) with a progressed mean Cobb angle of 39.5±17.3 degrees (range, 15 to 57 degrees). Congenital vertebral anomalies were observed in 1 patient. Three patients were treated surgically; 1 of the 3 patients had a surgical complication with loss of intraoperative neuromonitoring signals. Two patients had not undergone surgery at the last visit with a mean Cobb angle of 75.5 degrees. The mean postoperative follow-up for the surgical group (cases 1 to 3) was 3±3.6 years (range, 0.6 to 7.2 y) and the mean total follow-up for both groups was 6.6±2.5 years (range, 2.6 to 8.6 y). CONCLUSIONS: Scoliosis in ACS can represent a clinically significant problem that is underdiagnosed and overshadowed by the other severe medical complications associated with the syndrome. Our data suggest that scoliosis in patients with ACS is rapidly progressive and bracing is ineffective; early screening, close observation, and low threshold for referral to an orthopedic surgeon are crucial. LEVEL OF EVIDENCE: Level IV-case series.

Fibrous dysplasia of the proximal femur: surgical management options and outcomes.

PURPOSE: The management of proximal femoral deformity in fibrous dysplasia (FD) is a challenge to the orthopaedic surgeon. The purpose of this study was to analyze the various presentations of FD of proximal femur and the results of the various treatment modalities for the same. METHODS: This is a retrospective cohort study of 23 patients (24 femora) with FD who underwent surgery for the proximal femur. The study sample included 14 males, nine females. Ten patients had a monostotic disease, eight patients had polyostotic disease, and five patients had McCune-Albright syndrome. RESULTS: Group 1: shepherd crook deformity-included five patients who underwent femoral neck osteotomy. Four patients had intramedullary (IM) nailing with neck cross-pinning and all patients showed union. One patient was stabilized with external fixation, which failed. Group 2: nine patients (ten femora) presented with frank pathological fracture. Nine underwent fixation with IM nailing, one with locking plate and screws. Three patients had to undergo more than one procedure and all fractures showed good union. Group 3: nine patients who presented with bone cyst and pain. All patients underwent biopsy; four of them had curettage with bone graft. CONCLUSION: Shepherd crook deformity can be treated by a well-planned osteotomy and fixation with intramedullary implants with neck cross-pinning. Frank pathological fractures fixation with an intramedullary nail has excellent results even if not accompanied by resolution of the fibrodysplastic lesion. More than one procedure may be required. External fixation is not an optimal choice for fixation of femoral osteotomies in FD.

Bilateral C6 spondylolysis with spondylolisthesis in 3 adolescent siblings.

BACKGROUND: Cervical spondylolysis with spondylolisthesis is a rare condition in the pediatric population. The nature of this condition and clinical presentation are important to provide appropriate management. METHODS: This is a case report of 3 adolescent siblings who had C6 cervical spondylolysis with spondylolisthesis. RESULTS: Two cases were diagnosed insidiously with absence of neurological deficits and no instability on imaging and were treated conservatively. One case had a traumatic presentation associated with instability on imaging and was managed with cervical fusion and instrumentation. All 3 patients were doing well on a follow-up of >2 years. CONCLUSIONS: These cases suggest that cervical spondylolysis could be familial. The treatment was offered based on clinical presentation and presence of instability on radiographic studies. LEVEL OF EVIDENCE: Level IV.

[Scoliosis in children with chromosome 22q11.2 deletion syndrome]. / Scoliose bij kinderen met het 22q11.2-deletiesyndroom.

Chromosome 22q11.2 deletion syndrome (22q11DS) is a term used to describe a syndrome that consists of several clinical phenotypes, for example the DiGeorge syndrome, velocardiofacial syndrome and conotruncal anomaly face syndrome. These phenotypes share a common cause, i.e. deletion of a part of chromosome 22. An important clinical manifestation of this condition is scoliosis, which is estimated to occur in 15-50% of patients. We present three cases of children with scoliosis detected in early childhood. Two children were treated surgically because of progression of the deformity; in the third child surgery is being postponed as long as possible to allow further growth. We advise that every patient with 22q11DS should be screened for scoliosis. Furthermore, genetic counselling is required in all cases of scoliosis combined with distinct phenotypical characteristics.