The Recognition, Incidence, and Management of Spinal Cord Monitoring Alerts in Early-onset Scoliosis Surgery.

BACKGROUND: The objective of the research was to study the relevance of intraoperative neuromonitoring throughout all stages of surgical management in patients with progressive early-onset scoliosis (EOS).The routine monitoring of spinal cord potentials has gradually become standard of practice among spinal surgeons. However, there is not a consensus that the added expense of this technique necessitates monitoring in all stages of surgical management. METHODS: A retrospective review of 180 surgical cases of 30 patients with EOS from July 2003 to July 2012 was performed. All monitoring alerts as judged by the neuromonitoring team were identified. Both somatosensory-evoked potentials and transcranial electric motor-evoked potentials were studied and no limiting thresholds for reporting electrophysiological changes were deemed appropriate. RESULTS: Of 150 monitored cases there were 18 (12%) monitoring alerts. This represented 40% of the patient cohort over the 9-year study period. CONCLUSIONS: Index versus routine lengthening rate of alerts showed no significant difference in incidence of monitoring alerts. Conversely, several patients whose primary implantation surgeries were uneventful had monitoring alerts later in their treatment course. Intraoperative neuromonitoring is warranted throughout all stages of surgical management of EOS. LEVEL OF EVIDENCE: Level IV. This study is a retrospective review of surgical cases of 30 patients with EOS.

Outcomes after salvage procedures for the painful dislocated hip in cerebral palsy.

BACKGROUND: The painful dislocated hip in the setting of cerebral palsy is a challenging problem. Many surgical procedures have been reported to treat this condition with varying success rates. The purpose of this study is to retrospectively evaluate and compare the outcomes of 3 different surgical procedures performed at our institution for pain relief in patients with spastic quadriplegic cerebral palsy and painful dislocated hips. METHODS: A retrospective chart review of the surgical procedures performed by 5 surgeons for spastic, painful dislocated hips from 1997 to 2010 was performed. The procedures identified were (1) proximal femoral resection arthroplasty (PFRA); (2) subtrochanteric valgus osteotomy (SVO) with femoral head resection; and (3) proximal femur prosthetic interposition arthroplasty (PFIA) using a humeral prosthesis. Outcomes based on pain and range of motion were determined to be excellent, good, fair, or poor by predetermined criteria. RESULTS: Forty-four index surgeries and 14 revision surgeries in 33 patients with an average follow-up of 49 months met the inclusion criteria. Of the index surgeries, 12 hips were treated with a PFRA, 21 with a SVO, and 11 with a PFIA. An excellent or good result was noted in 67% of PFRAs, 67% of SVOs, and 73% of PFIAs. No statistical significance between these procedures was achieved. The 14 revisions were performed because of a poor result from previous surgery, demonstrating a 24% reoperation rate overall. No patients classified as having a fair result underwent revision surgery. All patients receiving revision surgery were eventually classified as having an excellent or good result. CONCLUSIONS: Surgical treatment for the painful, dislocated hip in the setting of spastic quadriplegic cerebral palsy remains unsettled. There continue to be a large percentage of failures despite the variety of surgical techniques designed to treat this problem. These failures can be managed, however, and eventually resulted in a good outcome. We demonstrated a trend toward better outcomes with a PFIA, but further study should be conducted to prove statistical significance. LEVEL OF EVIDENCE: III.

Assessment of Morbidity and Mortality Collection Data 2009.

STUDY DESIGN: A retrospective analysis of the morbidity and mortality data collected by the SRS in 2009 with comparison to previous years. OBJECTIVES: Objective of this study was to assess the new format of morbidity and mortality data collection by the SRS in 2009 and evaluate the data collected with comparison to previous years. SUMMARY OF BACKGROUND DATA: 2009 morbidity and mortality reporting format was dramatically changed from previous years. This was done in an attempt to simplify the reporting process and to narrow the reporting to only three sentinel events: death, blindness, and neurologic injury. Only deformity cases including scoliosis, kyphosis, and Grade III or greater spondylolisthesis were included. METHODS: Results were obtained from the SRS M & M reporting summary for 2009. These included detailed analysis for complications including death, blindness, and neurologic injury. These were compared to similar statistics obtained from the years dating back to 2001. Blindness has not previously been reported. RESULTS: 80.1% of SRS members submitted 35,267 deformity cases. Both the percentage of members submitting data and the number of deformity cases far exceeded any previous year total. 57.6% of cases involved scoliosis, 10.5% kyphosis, and 31.9% spondylolisthesis. Neurologic complications were lower in each major category (scoliosis, kyphosis, and spondylolisthesis) compared to previous years. The death rate was similar to prior reporting 0.12%. Three cases of blindness were reported, two occurred in AIS. All three resolved. CONCLUSIONS: The altered format and requirement for all members to participate has dramatically increased the total number of deformity cases reported and percent of membership responding. Neurologic injury rates are decreased from previous years. Three cases of blindness occurred, all of which resolved. Further collection of data is needed to elucidate mechanism and prevention.

Does bone morphogenetic protein increase the incidence of perioperative complications in spinal fusion? A comparison of 55,862 cases of spinal fusion with and without bone morphogenetic protein.

STUDY DESIGN: Retrospective review of a multi-institutional, multisurgeon database. OBJECTIVE: Assess for associations between bone morphogenetic protein (BMP) use and rate of complications in spinal fusion. SUMMARY OF BACKGROUND DATA: BMP is commonly used in spinal surgery to augment fusion; however, there is limited evidence demonstrating its associated complications. METHODS: We performed a retrospective analysis of all fusion cases submitted by members of the Scoliosis Research Society from 2004 to 2007. We stratified on the basis of the use of BMP and evaluated for complications and associated characteristics. RESULTS: A total of 55,862 cases of spinal fusion were identified with BMP used in 21% (11,933) of the cases. Excluding anterior cervical fusions, there were no significant differences between fusions with and without BMP with regard to overall complications (8.4% vs. 8.5%; P = 0.5), wound infections (2.4% vs. 2.4%; P = 0.8), or epidural hematomas/seromas (0.2% vs. 0.2%; P = 0.3). Anterior cervical fusions with BMP were associated with more overall complications (5.8% vs. 2.4%; P < 0.001) and more wound infections (2.1% vs. 0.4%; P < 0.001) than fusions without BMP. On multivariate analysis for thoracolumbar and posterior cervical fusions, BMP use was not a significant predictor of complications (P = 0.334; odds ratio = 1.039; 95% confidence interval = 0.961-1.124; covariates were BMP use, patient age, revision vs. primary surgery). Multivariate analysis for anterior cervical spinal fusion demonstrated that BMP use remained a significant predictor of complications (P < 0.001, odds ratio = 1.6; 95% confidence interval = 1.516-1.721), after adjusting for the effects of patient age and whether the surgery was a revision procedure. CONCLUSION: BMP use with anterior cervical fusion was associated with an increased incidence of complications. Use of BMP was not associated with more complications in thoracolumbar and posterior cervical fusions.

Rates of infection after spine surgery based on 108,419 procedures: a report from the Scoliosis Research Society Morbidity and Mortality Committee.

STUDY DESIGN: Retrospective review of a prospectively collected database. OBJECTIVE: Our objective was to assess the rates of postoperative wound infection associated with spine surgery. SUMMARY OF BACKGROUND DATA: Although wound infection after spine surgery remains a common source of morbidity, estimates of its rates of occurrence remain relatively limited. The Scoliosis Research Society prospectively collects morbidity and mortality data from its members, including the occurrence of wound infection. METHODS: The Scoliosis Research Society morbidity and mortality database was queried for all reported spine surgery cases from 2004 to 2007. Cases were stratified based on factors including diagnosis, adult (≥ 21 years) versus pediatric (<21 years), primary versus revision, use of implants, and whether a minimally invasive approach was used. Superficial, deep, and total infection rates were calculated. RESULTS.: In total, 108,419 cases were identified, with an overall total infection rate of 2.1% (superficial = 0.8%, deep = 1.3%). Based on primary diagnosis, total postoperative wound infection rate for adults ranged from 1.4% for degenerative disease to 4.2% for kyphosis. Postoperative wound infection rates for pediatric patients ranged from 0.9% for degenerative disease to 5.4% for kyphosis. Rate of infection was further stratified based on subtype of degenerative disease, type of scoliosis, and type of kyphosis for both adult and pediatric patients. Factors associated with increased rate of infection included revision surgery (P < 0.001), performance of spinal fusion (P < 0.001), and use of implants (P < 0.001). Compared with a traditional open approach, use of a minimally invasive approach was associated with a lower rate of infection for lumbar discectomy (0.4% vs. 1.1%; P < 0.001) and for transforaminal lumbar interbody fusion (1.3% vs. 2.9%; P = 0.005). CONCLUSION: Our data suggest that postsurgical infection, even among skilled spine surgeons, is an inherent potential complication. These data provide general benchmarks of infection rates as a basis for ongoing efforts to improve safety of care.

Usefulness of electromyography compared to computed tomography scans in pedicle screw placement.

STUDY DESIGN: This is a retrospective analysis of 30 pediatric deformity surgeries. OBJECTIVE: The purpose of this study was to evaluate the accuracy of neuromonitoring in comparison to postoperative computed tomography scans for pedicle screw position. SUMMARY OF BACKGROUND DATA: Triggered electromyography potentials in aiding the placement of lumbar pedicle screws are considered useful; however, this method is less accepted in thoracic screw placement. METHODS: Thirty pediatric deformity surgeries were reviewed. All screws were placed using fluoroscopic assistance. Electromyography data were obtained on all screws. Every patient underwent postoperative computed tomography scanning. Computed tomography scans were assessed by all authors, and each screw was classified. Sensitivity, specificity, negative predictive value, and likelihood ratios were determined for the cut-off value of an electromyography > or =6 mA. RESULTS: A total of 329 screws were reviewed. No complications occurred. An overall accuracy of 93% was obtained. No retained screw had greater than 2 mm medial pedicle wall breach. Nine screws were removed intraoperatively due to medial breach. The mean electromyography potential for all classes of screws was not statistically different (P > 0.1). The negative predictive value of the test was 0.92 in the thoracic spine and 0.93 in the lumbar spine. The negative likelihood ratios were 0.96 and 0.35 for the thoracic and lumbar spines respectively, and the positive likelihood ratio was 1.4 for the thoracic spine and 12.5 for the lumbar spine. CONCLUSION: Thoracic and lumbar pedicle screws are safe surgical options in the treatment of pediatric scoliosis. Comparison of electromyography potentials and postoperative computed tomography scans showed no statistically significant difference for all classes of screws. The likelihood ratio for electromyography testing was more clinically significant in the lumbar spine. A triggered electromyography value greater than or equal to 6 mA has a high likelihood of that screw being in the "safe zone." However, there is no true electromyography cut-off value that guarantees accurate placement and avoidance of neurologic injury.