Perioperative major neurologic deficits as a complication of spine surgery.

STUDY DESIGN: Retrospective review of spine surgery patients with new major neurologic complication. OBJECTIVE: To define the causes and severity of new neurologic damage to the spinal cord or cauda equina caused by spinal surgery. MATERIALS AND METHODS: Consult records were reviewed for all postoperative spine surgery patients referred to a tertiary spinal cord injury rehabilitation center over a 12-year period. Any patients with a new perioperative surgery-related decrement in American Spinal Injury Association (ASIA) Impairment Scale (AIS), loss of bowel or bladder function, or loss of ability to ambulate were examined and final 1-year gaps for neurologic loss reported. RESULTS: 64 patients had a new perioperative major neurologic event with: 41% thoracic, 39% cervical, and 20% lumbar; 61% intraoperative, 31% in the immediate 2-week postoperative period, 8% unknown. Chronic myelopathy (44%) was the most common indication. The causes of neurologic injury were postoperative fluid collection (25%), malposition of instrumentation (14%), traumatic decompression (14%), cord infarct (11%), deformity correction (2%), and unknown (34%). Overall, 87% lost the ability to ambulate and 66% lost volitional bowel-bladder control. AIS decrement and loss of ambulation and bowel-bladder function did not differ statistically significantly by surgical indication. However, among the main root causes, traumatic decompressions and cord infarcts had significantly worse neurologic deterioration than fluid collections or malposition of instrumentation. CONCLUSION: The relative rate of major neurologic injury in spine surgery is higher in thoracic and cervical cases at spinal cord levels, especially when done for myelopathy, even though lumbar surgeries are most common. The most common causes of neurologic injury were potentially avoidable postoperative fluid collections, malposition of instrumentation, and traumatic decompression.

Inadequate Surgical Decompression in Patients with Cervical Myelopathy: A Retrospective Review.

STUDY DESIGN: Retrospective study. OBJECTIVE: We reviewed cases of surgically treated cervical spondylotic myelopathy (CSM) or chronic, degenerative myelopathy of the subaxial cervical spine to study the incidence of inadequate surgical decompression. METHODS: We included all persons treated at our institution after a first surgical decompression for CSM over a 3-year period. Inadequate original surgical decompression was defined as neurologic decline within 12 months postoperatively and ongoing impingement of the spinal cord with <1-mm change in anteroposterior canal dimension from pre- to postoperative magnetic resonance imaging (MRI) leading to revision decompressive surgery. Revisions for other reasons were not counted as inadequate. RESULTS: Of 50 patients, 5 (10%) required revision decompression for neurologic decline and inadequate change in space available for the cord on postoperative imaging; 4 patients declined within the first 6 months and 1 patient at 8 months postoperatively. None of the 5 declined further after posterior revision, but none recovered from the interval loss. All 5 had undergone anterior approaches, for an anterior inadequacy rate of 23% (5 of 22). None of the 28 patients having posterior or combined approach declined at 2 years or had <1-mm change on postoperative MRI. The difference between anterior and posterior approaches was statistically significant (p = 0.018). CONCLUSIONS: The rate of inadequate surgical decompression for CSM was greater than expected in this series and directly associated with an anterior approach. No cases of inadequacy occurred for posterior or combined approaches. Postoperative neuroradiographic imaging such as MRI should be entertained routinely for this entity or at least for anterior-only approaches.

Accuracy of percutaneous lumbar pedicle screw placement using the oblique or "owl's-eye" view and novel guidance technology.

OBJECT: This study was conducted to assess the in vivo safety and accuracy of percutaneous lumbar pedicle screw placement using the owl's-eye view of the pedicle axis and a new guidance technology system that facilitates orientation of the C-arm into the appropriate fluoroscopic view and the pedicle cannulation tool in the corresponding trajectory. METHODS: A total of 326 percutaneous pedicle screws were placed from L-3 to S-1 in 85 consecutive adult patients. Placement was performed using simple coaxial imaging of the pedicle with the owl's-eye fluoroscopic view. NeuroVision, a new guidance system using accelerometer technology, helped align the C-arm trajectory into the owl's-eye view and the cannulation tool in the same trajectory. Postoperative fine-cut CT scans were acquired to assess screw position. Medical records were reviewed for complications. RESULTS: Five of 326 screws breached a pedicle cortex­all breaches were less than 2 mm­for an accuracy rate of 98.47%. Five screws violated an adjacent facet joint. All were at the S-1 superior facet and included in a fusion. No screw violated an adjacent mobile facet or disc space. There were no cases of new or worsening neurological symptoms or deficits for an overall clinical accuracy of 100%. CONCLUSIONS: The owl's-eye technique of coaxial pedicle imaging with the C-arm fluoroscopy, facilitated by NeuroVision, is a safe and accurate means by which to place percutaneous pedicle screws for degenerative conditions of the lumbar spine. This is the largest series reported to use the oblique or owl's-eye projection for percutaneous pedicle screw insertion. The accuracy of percutaneous screw insertion with this technique meets or exceeds that of other reported clinical series or techniques.

Scoliosis and interspinous decompression with the X-STOP: prospective minimum 1-year outcomes in lumbar spinal stenosis.

BACKGROUND CONTEXT: The X-STOP interspinous decompression device, as a treatment for neurogenic intermittent claudication (NIC) because of lumbar spinal stenosis (LSS), has been shown to be superior to nonoperative control treatment. Current Food and Drug Administration labeling limits X-STOP use to NIC patients with a maximum of 25° concomitant lumbar scoliosis. This value was arrived at arbitrarily by the device developers and is untested. PURPOSE: To determine X-STOP utility for NIC in patients with concomitant lumbar scoliosis. STUDY DESIGN: A prospective, single institution, clinical outcome study comparing patients with scoliosis with patients without scoliosis who underwent X-STOP interspinous decompression for NIC because of LSS. PATIENT SAMPLE: A cohort of 179 consecutive patients, 63 with scoliosis (Cobb angle 11° or more) and 116 without scoliosis, with symptoms attributable to NIC treated between January 2006 and May 2007, were included in the study. OUTCOME MEASURES: All patients completed self-reported preoperative and minimum 1-year postoperative outcome forms. Functional measures included Oswestry Disability Index (ODI), visual analog scale (VAS) pain score, and maximum walking and standing times in minutes. Three questions measured patient satisfaction: How satisfied were you with the procedure (very satisfied, somewhat satisfied, somewhat dissatisfied, or very dissatisfied); Would you have the procedure again? (yes or no); Would you recommend the procedure to a friend? (yes or no). METHODS: Before analysis, the 179 consecutive X-STOP patients were divided into three groups: Group 1 (controls without scoliosis, n=116); Group 2 (low scoliosis: 11-25°, n=41), and Group 3 (high scoliosis: 26° or more, n=22). The three groups were not statistically different for any preoperative functional scores. Groups were analyzed for pre- to postoperative functional change and level of satisfaction. Segmental scoliosis at the treated level was also analyzed. RESULTS: Fifty-six percent of Group 1 and Group 2 patients, but only 18% of Group 3 patients, achieved the success criterion of an ODI improvement of 15 or more points (Group 3 the outlier, p=.004). The satisfaction rate was Group 1, 76%; Group 2, 78%; Group 3, 59% (Group 3 the outlier, p=.0001). On average, all three groups improved for each outcome: Group 1 (ODI 17.3, VAS 2.0, standing time 39 minutes, and walking time 43 minutes), Group 2 (ODI 20.0, VAS 1.9, standing time 65 minutes, and walking time 64 minutes), Group 3 (ODI 7.2, VAS 0.9, standing time 18 minutes, and walking time 16 minutes). There was no statistical relationship between any outcome and segmental scoliosis. CONCLUSIONS: The outcome success rate for the X-STOP procedure to treat NIC is lower in patients with overall lumbar scoliosis more than 25° but is unaltered by segmental scoliosis at the affected level. Although patients and surgeons must be aware that the presence of more than 25° of scoliosis portends less favorable results with X-STOP implantation for NIC because of LSS, success in these patients is not precluded, and selection of treatment must be put into the context of individual patient risk and other treatment options.

Corrective osteotomies and osteosynthesis for supination contracture of the forearm in children.

PURPOSE: The purpose of this study was to present the authors' experience with corrective osteotomies of the forearm for supination contracture in children. METHODS: Fourteen patients with supination contracture of the forearm due to brachial plexus lesion (11), poliomyelitis residuals (2), or Monteggia fracture malunion (1) underwent distal ulnar osteotomy without fixation and subsequent midradial osteotomy with plate fixation to produce a position of greater pronation. A minimum of 6 months' follow-up was required to be included in the series. RESULTS: Ten boys and 4 girls whose mean age was 11 years underwent surgery between 1998 and 2006 to correct a supination contracture. The mean preoperative contracture measured 80 degrees of supination. The final mean postoperative correction was 104 degrees, whereas the final mean position of pronation was 24 degrees. CONCLUSIONS: Distal ulnar and midradial osteotomies are effective in the treatment of supination deformities of the forearm with little risk of complication or need for additional surgery. Radial fixation is important, but ulnar fixation is not required. Both osteotomies must be complete before plate fixation of the radius to realize maximal correction. LEVEL OF EVIDENCE: Level IV.

Identification of mitogen-activated protein kinase kinase as a chemoresistant pathway in MCF-7 cells by using gene expression microarray.

BACKGROUND: Components of the mitogen-activated protein kinase (MAPK) cascade have been implicated in apoptotic regulation. This study used gene expression profiling analysis to identify and implicate mitogen-activated protein kinase kinase (MEK5)-BMK1 (big mitogen-activated kinase-1)/extracellular signal related protein kinase (ERK5) pathway as a novel target involved in chemoresistance. METHODS: Differential gene expression between apoptotically sensitive (APO+) and apoptotically resistant (APO-) MCF-7 cell variants was determined by using microarray and confirmed by reverse transcriptase- polymerase chain reaction (RT-PCR). An apoptotic/viability reporter gene assay was used to deter-mine the effects of the transfection of a dominant-negative mutant of BMK1 (BMK1/DN) in conjunction with apoptotic-inducing agents (etoposide, tumor necrosis factor-alpha [TNF], or TNF-related apoptosis-inducing ligand [TRAIL]), with or without phorbol ester (PMA). RESULTS: Of the 1186 genes detected through microarray analysis, MEK5 was increased 22-fold in APO- cells. Overexpression of MEK5 was confirmed by using RT-PCR analysis. Expression of BMK1/DN alone resulted in a dose-dependent increase in cell death versus control (P <.05). In addition, BMK1/DN enhanced the sensitivity of MCF-7 cells to treatment-induced cell death (P <.05). The ability of PMA to partially suppress TRAIL- and TNF-induced cell death was inhibited by BMK1/DN. However, only TRAIL-induced activity suppression reached statistical significance (P <.05). CONCLUSIONS: The overexpression of MEK5 in APO- MCF-7 breast carcinoma cells shows that this MAPK signaling protein represents a potent survival molecule. Molecular inhibition of MEK5 signaling may represent a mechanism for sensitizing cancer cells to chemotherapeutic regimens.