Radiological and clinical assessment of the distraction achieved with remotely expandable growing rods in early onset scoliosis.

PURPOSES: Magnetically controlled growing rods (MCGR) allow controlled distraction of the immature spine for the treatment of early onset scoliosis. This study's primary aim was to determine the disparity between 'true' (TD) and 'intended' (ID) distraction. The secondary aim was to assess truncal growth and development during sequential lengthening. METHODS: Twenty-one patients with a maximum follow up of 37 months were included in the study. Patients in the study underwent three monthly distractions. The amount of TD was determined by measuring the expansion gap on dedicated fluoroscopic images of the actuator. The total TD to date was compared to the ID measurement reported on the external adjustment device (EAD). Weight, sitting and standing heights were recorded at each distraction. RESULTS: The average number of three monthly distractions was 8. The true to intended distraction ratio was calculated as 0.33. Patients who had undergone previous surgery gained less distraction with a ratio of 0.30 compared to patients undergoing MCGR as a primary procedure with a ratio of 0.35. Weight, sitting and standing heights increased in all patients by an average of 3.1 kg, 2.3 and 5.2 cm per year. The Cobb angle following surgical correction was maintained in 19 of 21 patients at the latest follow-up. CONCLUSIONS: The TI ratio of 0.33 suggests that for every unit of distraction registered on the EAD approximately 33 % of true distraction occurs in vivo. Increases in sitting and standing heights were observed in all patients in the study.

Incidence of proximal junctional kyphosis with magnetic expansion control rods in early onset scoliosis.

BACKGROUND: The introduction of magnetic expansion control growth rods for the surgical management of EOS has gained popularity. However, there are no published studies on the incidence of proximal junctional kyphosis (PJK) using this technique. PURPOSE: The aim of this study is to report the incidence of PJK following treatment with magnetic growth rods in EOS. METHODS: Retrospective review of data from 21 cases (12 males, 9 females) over 3 years. PJK was obtained from whole spine X-rays pre-op, immediate post-op and last follow-up. Cobb angle was measured between the superior end plate of vertebra two levels above the upper instrumented vertebra (UIV) and the inferior end plate of the UIV. A difference of >10° between the pre-operative x-rays and the last follow-up X-rays was recorded as PJK. RESULTS: 6/21 (28.6 %) had proximal junctional kyphosis of more than 10° at last follow-up. Average age was 5.3. Average follow-up was 32.5 months. All the patients with PJK were syndromic. Four out of these six patients were males (66 %). Average PJK angle was 25.55°. Average pre-operative kyphosis was 52.5°. Average number of distractions was 7.4. All six patients had syndromic association. 3/6 patients (50 %) were conversion cases treated with traditional growth rods previously (TGR). None of the patients required unplanned surgery for PJK. CONCLUSION: The incidence of PJK in EOS patients treated with magnetic rods is favourably comparable to that reported with traditional growth rods. Also, children who are male, syndromic, hyperkyphotic, and younger must be monitored closely.

Do surgeon credentials affect the rate of incidental durotomy during spine surgery.

PURPOSE: Incidental durotomy is a potential complication of spinal surgery which can cause a number of intra-operative and post-operative complications. The purpose of this study was to determine if the primary operator's credentials impacted on the incidence of durotomy intra-operatively. METHODS: Prospectively collected data of operator credentials in relation to the incidence of durotomy were acquired from the International Eurospine Tango database. The significance of variability and risk factors between operators was measured using the Chi-squared test. RESULTS: Data from a total of 3,764 patients were captured from the Tango registry. Of these 162 (4.3%) had a durotomy. Of the total number of patients, the primary operator was neurosurgical in 1,369 (36.4%) cases; orthopaedic in 180 (4.8%) cases; other (pre-certification) in 236 (6.3%) cases; specialised spine surgeon in 1,741 (46.3%) cases; 6 cases had missing operator data. cerebrospinal fluid (CSF) leak occurred in 57 (4.16%) of neurosurgeon-operated cases; 5 (2.78%) orthopaedic-operated cases; 19 (4.06%) of other surgeon-operated cases; and 81 (4.65%) in specialised spine surgeon-operated cases. Using Chi-squared test, the significance of the variation in incidence of CSF leak between primary operator groups was not statistically significant (P = 0.1405). CONCLUSION: From the data captured and analysed, the rate of durotomy ranged from 2.78 to 4.65% between operator groups with a mean rate of 4.3%. The primary operator credentials do not appear to significantly impact the rate of durotomy in spine surgery.

An NIHR-approved two-year observational study on magnetically controlled growth rods in the treatment of early onset scoliosis.

Aims: The primary aim of this study was to evaluate the performance and safety of magnetically controlled growth rods in the treatment of early onset scoliosis. Secondary aims were to evaluate the clinical outcome, the rate of further surgery, the rate of complications, and the durability of correction. Patients and Methods: We undertook an observational prospective cohort study of children with early onset scoliosis, who were recruited over a one-year period and followed up for a minimum of two years. Magnetically controlled rods were introduced in a standardized manner with distractions performed three-monthly thereafter. Adverse events which were both related and unrelated to the device were recorded. Ten children, for whom relevant key data points (such as demographic information, growth parameters, Cobb angles, and functional outcomes) were available, were recruited and followed up over the period of the study. There were five boys and five girls. Their mean age was 6.2 years (2.5 to 10). Results: The mean coronal Cobb angle improved from 57.6° (40° to 81°) preoperatively, 32.8° (28° to 46°) postoperatively, and 41° (19° to 57°) at two years. Five children had an adverse event, with four requiring return to theatre, but none were related to the device. There were no neurological complications or infections. No devices failed. One child developed a proximal junctional kyphosis. The mean gain in spinal column height from T1 to S1 was 45.4 mm (24 to 81) over the period of the study. Conclusion: Magnetically controlled growth rods provide an alternative solution to traditional growing rods in the surgical management of children with early onset scoliosis, supporting growth of the spine while controlling curve progression. Their use has clear psychosocial and economic benefits, with the reduction of the need for repeat surgery as required with traditional growing rods. Cite this article: Bone Joint J 2018;100-B:507-15.

A six-year observational study of 31 children with early-onset scoliosis treated using magnetically controlled growing rods with a minimum follow-up of two years.

Aims: Magnetically controlled growing rod (MCGR) systems use non-invasive spinal lengthening for the surgical treatment of early-onset scoliosis (EOS). The primary aim of this study was to evaluate the performance of these devices in the prevention of progression of the deformity. A secondary aim was to record the rate of complications. Patients and Methods: An observational study of 31 consecutive children with EOS, of whom 15 were male, who were treated between December 2011 and October 2017 was undertaken. Their mean age was 7.7 years (2 to 14). The mean follow-up was 47 months (24 to 69). Distractions were completed using the tailgating technique. The primary outcome measure was correction of the radiographic deformity. Secondary outcomes were growth, functional outcomes and complication rates. Results: The mean Cobb angle was 54° (14° to 91°) preoperatively and 37° (11° to 69°) at the latest follow-up (p < 0.001). The mean thoracic kyphosis (TK) was 45° (10° to 89°) preoperatively and 42° (9° to 84°) at the latest follow-up. The mean T1-S1 height increased from 287 mm (209 to 378) to 338 mm (240 to 427) (p < 0.001) and the mean sagittal balance reduced from 68 mm (-76 to 1470) preoperatively to 18 mm (-32 to 166) at the latest follow-up. The mean coronal balance was 3 mm (-336 to 64) preoperatively and 8 mm (-144 to 64) at the latest follow-up. The mean increase in weight and sitting and standing height at the latest follow-up was 45%, 10% and 15%, respectively. The mean Activity Scale for Kids (ASKp) scores increased in all domains, with only personal care and standing skills being significant at the latest follow-up (p = 0.02, p = 0.03). The improvements in Cobb angle, TK and T1-S1 heights were not related to gender, the aetiology of the EOS, or whether the procedure was primary or conversion from a conventional growing rod system. A total of 21 children developed 23 complications at a rate of 0.23 per patient per year. Seven developed MCGR-specific complications. Complications developed at a mean of 38 months (3 to 67) after the initial surgery and required 22 further procedures. Children who developed a complication were more likely to be younger, have syndromic EOS, and have a single-rod construct (6.9 versus 9.3 years, p = 0.034). Conclusion: The progression of EOS can be controlled using MCGRs allowing growth and improved function. Younger and syndromic children are more likely to develop complications following surgery. Cite this article: Bone Joint J 2018;100-B:1187-1200.

Quantifying the 'law of diminishing returns' in magnetically controlled growing rods.

AIMS: Magnetically controlled growing rods (MCGRs) allow non-invasive correction of the spinal deformity in the treatment of early-onset scoliosis. Conventional growing rod systems (CGRS) need repeated surgical distractions: these are associated with the effect of the 'law of diminishing returns'. The primary aim of this study was to quantify this effect in MCGRs over sequential distractions. PATIENTS AND METHODS: A total of 35 patients with a maximum follow-up of 57 months were included in the study. There were 17 boys and 18 girls with a mean age of 7.4 years (2 to 14). True Distraction (TD) was determined by measuring the expansion gap on fluoroscopy. This was compared with Intended Distraction (ID) and expressed as the 'T/I' ratio. The T/I ratio and the Cobb angle were calculated at several time points during follow-up. RESULTS: The mean follow-up was 30 months (6 to 57). There was a significant decrease in the mean T/I ratio over time (convex rod at 3 months 0.81, sd 0.58 vs 51 months 0.17, sd 0.16, p = 0.0001; concave rod at 3 months 0.93, sd 0.67 vs 51 months 0.18, sd 0.15, p = 0.0001). A linear decline of the mean T/I ratios was noted for both convex rods (r2 = 0.90, p = 0.004) and concave rods (r2 = 0.81, p = 0.015) over 51 months. At the 24-month follow-up stage, there was a significant negative correlation between the mean T/I ratio of the concave rod with weight (r = -0.59, p = 0.01), age (r = -0.59, p = 0.01), and BMI of the child (r = -0.54, p = 0.01). CONCLUSIONS: The 'law of diminishing returns' is also seen after serial distraction using MCGR. Compared to previously published data for CGRS, there is a gradual linear decline rather than a rapid initial decline in lengthening. In older, heavier children a reduced distraction ratio in the concave rod of the MCGR device is noted over time. Cite this article: Bone Joint J 2017;99-B:1658-64.

The use of magnetically-controlled growing rods to treat children with early-onset scoliosis: early radiological results in 19 children.

AIMS: We undertook a prospective non-randomised radiological study to evaluate the preliminary results of using magnetically-controlled growing rods (MAGEC System, Ellipse technology) to treat children with early-onset scoliosis. PATIENTS AND METHODS: Between January 2011 and January 2015, 19 children were treated with magnetically-controlled growing rods (MCGRs) and underwent distraction at three-monthly intervals. The mean age of our cohort was 9.1 years (4 to 14) and the mean follow-up 22.4 months (5.1 to 35.2). Of the 19 children, eight underwent conversion from traditional growing rods. Whole spine radiographs were carried out pre- and post-operatively: image intensification was used during each lengthening in the outpatient department. The measurements evaluated were Cobb angle, thoracic kyphosis, proximal junctional kyphosis and spinal growth from T1 to S1. RESULTS: The mean pre-, post-operative and latest follow-up Cobb angles were 62° (37.4 to 95.8), 45.1° (16.6 to 96.2) and 43.2° (11.9 to 90.5), respectively (p < 0.05). The mean pre-, post-operative and latest follow-up T1-S1 lengths were 288.1 mm (223.2 to 351.7), 298.8 mm (251 to 355.7) and 331.1 mm (275 to 391.9), respectively (p < 0.05). In all, three patients developed proximal pull-out of their fixation and required revision surgery: there were no subsequent complications. There were no complications of outpatient distraction. CONCLUSIONS: Our study shows that MCGRs provide stable correction of the deformity in early-onset scoliosis in both primary and revision procedures. They have the potential to reduce the need for multiple operations and thereby minimise the potential complications associated with traditional growing rod systems. Cite this article: Bone Joint J 2016;98-B:1240-47.

Contribution of substance abuse and HIV infection to psychiatric distress in an inner-city African-American population.

We used Symptom Checklist 90-Revised (SCL90-R) to investigate psychiatric symptom severity in African-American drug-abusing individuals. Three hundred and seventeen African-American volunteers (52 control subjects; 265 drug users) were recruited, 19.2% of whom were HIV-positive. The impact of drug of choice or HIV status on mental distress was assessed. Symptomatic HIV-positive participants were excluded. The intake SCL90-R, Addiction Severity Index, and demographic data were subjected to regression analyses. Drug-abusing African Americans reported increased global distress, a finding that remained robust after we adjusted for HIV status, gender, age, and education. Drug of choice had no influence on the severity of global mental distress in our sample. Asymptomatic HIV-positive African Americans who abused drugs reported more distress than the HIV-negative drug users. Levels of global distress were similar in the HIV-negative and the HIV-positive controls. Subscales of the SCL90-R showed more symptom severity among drug-using, compared with nonusing, African Americans. Except for paranoia, anxiety, and obsessive-compulsive subscales, other symptom dimensions were significantly elevated in HIV-positive, compared with HIV-negative, drug abusers. When taken together, these findings suggest that drug abuse can exacerbate the severity of mental distress in HIV-positive patients. Treatment of these patients may be more successful if both sets of needs are addressed with matched interventions.