The implant density does not change the correction rate of the main and the accompanying curves: A comparison between consecutive and intermittent pedicle screw constructs

OBJECTIVE

The aim of this study was to evaluate the clinical outcomes and the coronal correction rate of the main and accompanying curves of adolescent idiopathic scoliosis (AIS) corrected with pedicle screws inserted consecutively or intermittently.

METHODS

The prospectively collected data of 60 patients (8 men and 52 women; mean age: 14.6±2.5 years) who underwent corrective surgery for AIS between January 2010 and December 2015 were reviewed retrospectively. Two groups were constituted according to the pedicle screw construct type: consecutive pedicle screw construct (CPSC) and intermittent pedicle screw construct (IPSC) groups. The preoperative, early postoperative, and 24-month follow-up radiographs and the Scoliosis Research Society-22 (SRS-22) scores were reevaluated. The Cobb angle of the main and accompanying curves, the correction rate, and the flexibility of the curves were calculated.

RESULTS

The mean preoperative Cobb angles were 57.03° and 57.46°, the mean postoperative Cobb angles were 14.93° and 14.4°, and the mean correction rates were 76.22% and 75.31% in IPSC and CPSC groups, respectively (p>0.05). The preoperative and postoperative accompanying curve magnitudes and correction rates were similar (p>0.05). These radiographic outcomes were also consistent with the SRS-22 scores.

CONCLUSION

Both the pedicle screw constructs had satisfactory outcomes following the surgery, which were confirmed by both the SRS-22 scores and radiographs taken perioperatively and at follow-ups. The IPSC and CPSC groups did not demonstrate a significant change in the correction rate of the main and minor or major accompanying structural and nonstructural curves, and also in the SRS-22 scores.

LEVEL OF EVIDENCE

Level III, Retrospective comparative study.

Epidermal growth factor enhances spinal fusion: Posterolateral lumbar fusion model on rats

Objective

The aim of this study was to investigate the effects of human recombinant epidermal growth factor (EGF) on posterolateral lumbar fusion in a rat model.

Methods

36 male Sprague Dawley rats underwent posterolateral fusion at L4-5 level. They were randomly assigned to 3 groups: 1- Sham control group where no local augmentation was made, 2- Local Hydoxyapatite β-tricalcium phosphate (HA/β-TCP) augmentation group and 3- Local HA/β-TCP + EGF augmentation group. Rats were euthanized at 8 weeks post-surgery. 6 rats from each group were selected for manual palpation examination, micro-computed tomography analysis and histologic analysis; and the rest was used for biomechanical analysis.

Results

Based on manual palpation, there was no fusion in the sham control group. Fusion rate was 33.3% in the HA/β-TCP group and 66.7% in the HA/β-TCP + EGF group (p = 0.085). Micro-CT results revealed that new bone formation was higher in the HA/β-TCP + EGF group (BV/TV: 40% vs. 65%) (p = 0.004). Histologically newly formed bone tissue was more pronounced in the EGF group and compacted and bridging bone spicules were observed. The median maximum bending moment values were 0.51 Nmm (0.42–0.59), 0.73 Nmm (0.49–0.88) and 0.91 Nmm (0.66–1.03) in the sham control, HA/β-TCP and HA/β-TCP + EGF groups, respectively (p = 0.013). The median stiffness values were 1.69 N/mm (1.12–2.18), 1.68 N/mm (1.13–2.74) and 3.10 N/mm (1.66–4.40) as in the previous order (p = 0.087).

Conclusion

This study demonstrates that EGF enhances posterolateral lumbar fusion in the rat model. EGF in combination with ceramic grafts increased the fusion rates. Our findings may provide insights to further studies, investigating EGF's clinical usage as an alternative fusion enhancer.

Assessment of variability in Turkish spine surgeons' trauma practices

OBJECTIVES

The aim of this study was to analyse the variability among Turkish spinal surgeons in the management of thoracolumbar fractures by carrying out a web survey.

METHODS

An invitation text and web-link of the survey were sent to the members of the Turkish Spine Society mail group. A fictitious spine trauma vignette, a 23 year-old male with a L1 burst fracture, was presented and 25 questions were asked to participants. Variability of answers in a given question was assessed with the Index of Qualitative Variation (IQV). Questions with high IQV values (>%80) were selected to evaluate the relation between participant factors (speciality, age, degree and experience level of the surgeon, type of the work centre and volume of the trauma patients).

RESULTS

Sixty-four (88%) among the 73 participating surgeons completed the survey. 45 (70%) of them were orthopaedic surgeons and 19 (30%) were neurosurgeons. 11 questions had very high variability (IQV ≥ 0.80), 5 had high variability (0.58-0.75) and 2 had low variability (IQV≤0.20). The question with the highest variability was related to the use of brace after surgery (IQV = 0.93). Following one was about the selection of fixation levels (IQV = 0.91). Neurosurgeons were more likely to use brace postoperatively and professors were less likely to perform decompression.

CONCLUSION

This survey shows that thoracolumbar spine trauma practice significantly varies among Turkish spine surgeons. Surgeons' characteristics affected some specific answers. Lack of enough knowledge about spine trauma care, fracture classifications and surgical techniques and/or ethical factors may be other reasons for this variability.

Comparison of multimodal intraoperative neurophysiological monitoring efficacy in early childhood and school aged children undergoing spinal surgery

OBJECTIVE

The aim of this study was to compare the performance of multimodal intraoperative neurophysiological monitoring (MIONM) in children below and over 6 years of age.

METHODS

43 children, diagnosed with spinal pathologies were divided into two cohorts according to their age and enrolled in the study. Those under the age of 6 consisted group A, whereas those between the age of 6 and 11 consisted group B. All patients underwent spinal surgical procedures according to their diagnosis. A standard anesthesia protocol was given to both groups. Baseline somatosensory evoked potentials (SSEPs) and transcranial electrical motor evoked potentials (tcMEPs) were recorded and evaluated at specific time points for each patient.

RESULTS

Except for the SSEPs in three cases, tcMEPs and SSEPs were recorded for all patients. There was no false-negative whereas 9 false positive recordings due to physiological conditions that all recovered intraoperatively. In 10 patients, MIOMN recorded more than %50 decrement, in which 8 had the kyphosis component. The tcMEPs fully recovered by the end of the operation except for the patient with post-tuberculosis kyphosis. There was no statistically significant difference in the mean threshold values with regard to transcranial stimulus intensity for the tcMEPs between the two groups.

CONCLUSION

Compared to school aged children, both SSEPs, tcMEPs recordings are feasible and MIONM is effective for early childhood patients undergoing spinal surgery.

LEVEL OF EVIDENCE

Level III, Diagnostic Study.

Comparison of effectiveness of kyphoplasty and vertebroplasty in patients with osteoporotic vertebra fractures

Objective

The aim of this study was to compare the functional and radiological outcomes of vertebroplasty and kyphoplasty in patients with osteoporotic vertebra fractures.

Methods

The files of the patients who underwent vertebroplasty or kyphoplasty for osteoporotic vertebrae fractures were retrieved from the archives. Forty-three patients with complete follow-up data were included in the study group. The patients were evaluated for radiological outcomes in terms of local kyphosis angle, wedging index, compression ratio, visual analog pain scale (VAS) and Oswestry Disability Index (ODI).

Results

In the study group, kyphoplasty was performed on 24 vertebrae of 22 patients (17 females, 5 males; mean age: 73 years) whereas vertebroplasty was applied on 24 vertebrae of 21 (16 females, 5 males; mean age: 74.7 years) patients. The mean follow-up time was 26 months. When the VAS and ODI values of the groups were analyzed, both groups showed statistically significant progress after the operation. Radiological data showed that the kyphoplasty group showed statistically significant improvement in the sagittal index values whereas the vertebroplasty group did not. The overall complication ratio was 4%.

Conclusion

Both vertebroplasty and kyphoplasty are effective treatment methods for functional recovery and pain relief in osteoporotic fractures of the vertebra. Although radiological outcomes of the kyphoplasty seem to be better, this does not have any clinical relevance. We suggest vertebroplasty over kyphoplasty since it is an easier method to manage.

Level of evidence

Level III, Therapeutic study.

Bilateral knee and right ankle osteonecrosis in an adolescent girl with acute lymphoblastic leukemia

Although rare, avascular necrosis of bone is a serious and incapacitating complication seen in children with acute lymphoblastic leukemia receiving high dose steroids. Here we present a 16 year-old girl who developed bilateral knee and right ankle avascular osteonecrosis one year after intensive chemotherapy for medium risk acute lymphoblastic leukemia. Indirect curettage of necrotic tissue and bone grafting were performed for both knees whereas conservative measures had been sufficient for the ankle. Early recognition of this condition is important in prevention of disabling sequela in skeletal system.