The use of fusion mass screws in revision spinal deformity surgery.

STUDY DESIGN: To report the use of a posterior based 'fusion mass screw' (FMS) as a primary or salvage fixation point in a revision spinal deformity following a previous posterior spinal fusion (PSF). Our experience of this technique in a case report and the clinical and radiological results are reported. OBJECTIVES: To describe the technique and uses of the FMS as a primary/salvage fixation point in osteotomies in previously arthrodesed spinal deformity surgery. Obtaining fixation points to correct and stabilize a spinal deformity with coronal and sagittal imbalance in a previously arthrodesed spine during revision surgery can be challenging. Several alternate pedicle fixation techniques and laminar screw techniques have been described in the literature. However, there is no description of these techniques in the presence of a spinal fusion with distorted anatomy. A pedicle screw placed coronally across a thick posterior fusion mass can provide an alternate method of fixation in these cases with complex anatomy. METHODS: Two cases of complex spinal deformity and corrective spinal osteotomies using fusion mass screws (FMSs) placed coronally across the posterior fusion mass are described. The first case is an 8-year-old patient with Marfan's syndrome who developed a crank shaft phenomenon and severe thoracolumbar kyphoscoliosis following a previous PSF. The second case is a 53-year-old patient with coronal imbalance following PSF as a child using Harrington instrumentation who developed distal degeneration with stenosis in her remaining mobile segments. Both patients underwent vertebral column resection and osteotomy closure plus stabilisation using FMS. The clinical and radiological results and technique for insertion of the FMS are described. CONCLUSION: In this report, we present a novel method of using posterior FMSs to achieve fixation and correction in cases of revision deformity surgery with difficult anatomy. While we feel pedicle screws are the gold standard in deformity correction, knowledge of alternatives such as the FMS can allow surgeons to achieve stable constructs when faced with challenging situations.

Risk Factors for Postoperative Coronal Balance in Adult Spinal Deformity Surgery.

STUDY DESIGN: A retrospective case-control study. OBJECTIVES: To determine factors influencing the ability to achieve coronal balance following spinal deformity surgery. METHODS: Following institutional ethics approval, the radiographs of 47 patients treated for spinal deformity surgery with long fusions to the pelvis, were retrospectively reviewed. The postoperative measurements included coronal balance, L4 tilt, and L5 tilt, levels fused, apical vertebral translation and maximum Cobb angle. L4 and L5 tilt angles were measured between the superior endplate and the horizontal. Sagittal parameters including thoracic kyphosis, lumbar lordosis, pelvic incidence, and sagittal vertical axis were recorded. Coronal balance was defined as the distance between the central sacral line and the mid body of C7 being ≤40 mm. Surgical factors, including levels fused, use of iliac fixation with and without connectors, use of S2A1 screws, interbody devices, and osteotomies. Statistical tests were performed to determine factors that contribute to postoperative coronal imbalance. RESULTS: Of the 47 patients reviewed, 32 were balanced after surgery and 14 were imbalanced. Coronal balance was 1.30 cm from center in the balanced group compared to 4.83 cm in the imbalanced group (P < .01). Both L4 and L5 tilt were statistically different between the groups. Gender and the use of transverse connectors differed between the groups but not statistically. CONCLUSIONS: In adult spinal deformity patients undergoing primary fusions to the pelvis, the ability to level the coronal tilt of L4 and L5 had the greatest impact on the ability to achieve coronal balance in this small series. A larger prospective series can help validate this important finding.

Cognitive Rest and Graduated Return to Usual Activities Versus Usual Care for Mild Traumatic Brain Injury: A Randomized Controlled Trial of Emergency Department Discharge Instructions.

OBJECTIVES: It is estimated that 15%-25% of patients with a mild traumatic brain injury (MTBI) diagnosed in the emergency department (ED) will develop postconcussive syndrome. The objective of this study was to determine if patients randomized to graduated return to usual activity discharge instructions had a decrease in their Post-Concussion Symptom Score (PCSS) 2 weeks after MTBI compared to patients who received usual care MTBI discharge instructions. METHODS: This was a pragmatic, randomized trial of adult (18-64 years) patients of an academic ED (annual census 60,000) diagnosed with MTBI occurring within 24 hours of ED visit. The intervention group received cognitive rest and graduated return to usual activity discharge instructions, and the control group received usual care discharge instructions that did not instruct cognitive rest or graduated return. Patients were contacted by text message or phone 2 and 4 weeks post-ED discharge and asked to complete the PCSS, a validated, 22-item questionnaire, to determine if there was a change in their symptoms. Secondary outcomes included change in PCSS at 4 weeks, number follow-up physician visits, and time off work/school. RESULTS: A total of 118 patients were enrolled in the study (58 in the control group and 60 in the intervention). The mean (±SD) age was 35.2 (±13.7) years and 43 (36.4%) were male. There was no difference with respect to change in PCSS at 2 weeks (10.5 vs. 12.8; ∆2.3, 95% confidence interval [CI] = 7.0 to 11.7) and 4 weeks post-ED discharge (21.1 vs 18.3; ∆2.8, 95% CI = 6.9 to 12.7) for the intervention and control groups, respectively. The number of follow-up physician visits and time off work/school were similar when the groups were compared. Thirty-eight (42.2%) and 23 (30.3%) of patients in this cohort had ongoing MTBI symptoms (PCSS > 20) at 2 and 4 weeks, respectively. CONCLUSIONS: Results from this study suggest graduated return to usual activity discharge instructions do not impact rate of resolution of MTBI symptoms 2 weeks after ED discharge. Given that patients continue to experience symptoms 2 and 4 weeks after MTBI, more investigation is needed to determine how best to counsel and treat patients with postconcussive symptoms.

T12 Sagittal Tilt Predicts Thoracic Kyphosis.

STUDY DESIGN: Retrospective review and analysis of lateral long cassette radiographs. OBJECTIVE: The purpose of this paper is to assess whether certain radiographic features routinely seen on lumbar radiographs can predict a structural thoracic deformity. SUMMARY OF BACKGROUND DATA: Obtaining proper sagittal alignment is an essential factor contributing to favorable clinical outcomes following spinal deformity surgery. The majority of patients treated with lumbar fusions do not undergo long cassette radiographs, and therefore physicians must rely upon clinical examination to determine the presence of a structural thoracic kyphotic deformity. METHODS: A total of 193 consecutive lateral long cassette radiographs of outpatients without prior spine surgery presenting to a spine surgeon were independently reviewed. Statistical analysis was performed on sagittal parameters that included the T12 slope, pelvic incidence, sacral slope, T2-T12 and T5-T12 kyphosis, and T12-S1 lordosis, and correlated with patient demographics. RESULTS: The age of the patient combined with the sagittal slope of T12 can be used to assess a patient's risk of having a structural thoracic deformity defined in this series as >35 degrees from T5 to T12 and >40 degrees from T2 to T12. Based on our findings, for a given 20-year-old patient, the threshold T12 sagittal angle was about 17-18 degrees. This angle decreased 2-3 degrees per decade so that the threshold value was 12-13 degrees by age 40, 7-9 degrees by age 60, and 3-4 degrees by age 80. CONCLUSION: Age and the sagittal slope of the 12th thoracic vertebra are effective predictors of kyphosis between T2-T12 and T5-T12. This information may be used to determine the need for long cassette radiographs to further examine the possible presence of kyphotic deformity in the thoracic spine. LEVEL OF EVIDENCE: Level IV.

The Deformity Angular Ratio: Does It Correlate With High-Risk Cases for Potential Spinal Cord Monitoring Alerts in Pediatric 3-Column Thoracic Spinal Deformity Corrective Surgery?

STUDY DESIGN: A retrospective analysis. OBJECTIVE: The purpose of this study was to determine whether the deformity angular ratio (DAR) can reliably assess the neurological risks of patients undergoing deformity correction. SUMMARY OF BACKGROUND DATA: Identifying high-risk patients and procedures can help ensure that appropriate measures are taken to minimize neurological complications during spinal deformity corrections. Subjectively, surgeons look at radiographs and evaluate the riskiness of the procedure. However, 2 curves of similar magnitude and location can have significantly different risks of neurological deficit during surgery. Whether the curve spans many levels or just a few can significantly influence surgical strategies. Lenke et al have proposed the DAR, which is a measure of curve magnitude per level of deformity. METHODS: The data from 35 pediatric spinal deformity correction procedures with thoracic 3-column osteotomies were reviewed. Measurements from preoperative radiographs were used to calculate the DAR. Binary logistic regression was used to model the relationship between DARs (independent variables) and presence or absence of an intraoperative alert (dependent variable). RESULTS: In patients undergoing 3-column osteotomies, sagittal curve magnitude and total curve magnitude were associated with increased incidence of transcranial motor evoked potential changes. Total DAR greater than 45° per level and sagittal DAR greater than 22° per level were associated with a 75% incidence of a motor evoked potential alert, with the incidence increasing to 90% with sagittal DAR of 28° per level. CONCLUSION: In patients undergoing 3-column osteotomies for severe spinal deformities, the DAR was predictive of patients developing intraoperative motor evoked potential alerts. Identifying accurate radiographical, patient, and procedural risk factors in the correction of severe deformities can help prepare the surgical team to improve safety and outcomes when carrying out complex spinal corrections. LEVEL OF EVIDENCE: 3.

Modified T4 hemivertebrectomy for persistent high left shoulder after surgery for double thoracic scoliosis.

STUDY DESIGN: Case report. OBJECTIVE: To surgically regain shoulder balance in patients with adolescent idiopathic scoliosis after loss of alignment after posterior fusion for Lenke II deformity correction. SUMMARY OF BACKGROUND DATA: Shoulder balance is known to have a large effect on patient satisfaction after deformity correction. Previous studies have outlined guidelines for determining levels of instrumentation to prevent postoperative high left shoulder. However, to our knowledge, no study has provided instructions on how to correct coronal imbalance in patients with previously fused scoliosis. We describe a case using a T4 unilateral pedicle subtraction osteotomy and contralateral Smith-Petersen osteotomy to treat high left shoulder in a patient who had previously undergone posterior instrumented fusion for adolescent idiopathic scoliosis. METHODS: The radiographs and clinical charts were reviewed for a 17-year-old female patient treated with a revision fusion and modified T4 hemivertebrectomy for a persistently high left shoulder after previous correction of a Lenke II idiopathic scoliosis. RESULTS: A reduction in the T1 tilt angle from 19.2° to 10.1° and an improvement in the coronal Cobb angle of the proximal thoracic curve from 37° to 17° were obtained. Shoulder balance was greatly improved. CONCLUSION: A proximal thoracic partial vertebrectomy with unilateral pedicle subtraction osteotomy and contralateral Smith-Petersen osteotomy is a technique that can be used to successfully correct fixed shoulder imbalance after posterior instrumented fusion of a double thoracic adolescent idiopathic scoliosis. LEVEL OF EVIDENCE: N/A.

Tension Pneumothorax as a Complication of Inadvertent Pleural Tears During Posterior Spinal Surgery.

OBJECTIVE: To review and expose the occurrences of tension pneumothorax as a result of pleural tear during posterior spinal surgery. METHODS: Intraoperative reports were retrospectively reviewed for 2 patients who underwent posterior spinal fusion and experienced pleural tear and subsequent tension pneumothorax. Surgical decisions for recognition and treatment were also reviewed. RESULTS: Unrecognized pleural tearing led to the formation of tension pneumothorax in both patients studied. Onset of respiratory signs and symptoms were delayed, occurring in the recovery room for the first patient and intraoperatively for the second. Both patients were successfully treated with conversion to open pneumothorax and placement of chest tubes. CONCLUSIONS: Tension pneumothorax is a complication that can arise during posterior thoracic spinal surgery as a result of an inadvertent pleural tear. Awareness of this potentially fatal complication will greatly help in the timely recognition and treatment of this condition if this situation occurs. The authors recommend a low threshold for chest tube placement in patients with known or suspected pleural tears or in patients with undiagnosed respiratory failure undergoing posterior thoracic spine surgery.