Ahmad Nassr

The incidence of C5 palsy after multilevel cervical decompression procedures: a review of 750 consecutive cases

Study Design. Retrospective review of 750 consecutive multilevel cervical spine decompression surgeries performed by a single spine surgeon. Objective. To determine the incidence of C5 palsy in a large consecutive series of multilevel cervical spine decompression procedures. Summary of Background Data. Palsy of the C5 nerve is a well-known potential complication of cervical spine surgery with reported rates ranging from 0% to 30%. The etiology remains uncertain but has been attributed to iatrogenic injury during surgery, tethering from shifting of the spinal cord, spinal cord ischemia, and reperfusion injury of the spinal cord. Methods. We included patients undergoing multilevel cervical corpectomy, corpectomy with posterior fusion, posterior laminectomy and fusion, and laminoplasty. Exclusion criteria included lack of follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or surgery not involving the C5 level. Incidence of C5 palsy was determined and compared to determine whether significant differences existed among the various procedures, patient age, sex, revision surgery, preoperative weakness, diabetes, smoking, number of levels decompressed, and history of previous upper extremity surgery. Results. Of the 750 patients, 120 were eliminated on the basis of the exclusion criteria. The 630 patients included in the analysis consisted of 292 females and 338 males. The mean age was 58 years (range, 19–87). The incidence of C5 nerve palsy for the entire group was 42 of 630 (6.7%). The incidence was highest for the laminectomy and fusion group (9.5%), followed by the corpectomy with posterior fusion group (8.4%), the corpectomy group (5.1%), and finally the laminoplasty group (4.8%), although these differences did not reach statistical significance. There was a significantly higher incidence in males (8.6% vs. 4.5%, P = 0.05). Conclusion. Incidence of C5 nerve palsy after cervical spine decompression was 6.7%. This is consistent with previously published studies and represents the largest series of North American patients to date. There is no statistically significant difference in incidence of C5 palsy based on surgical procedure, although there was a trend toward higher rates with laminectomy and fusion.

Does incorrect level needle localization during anterior cervical discectomy and fusion lead to accelerated disc degeneration

Study Design. Retrospective radiographic analysis. Objective. To retrospectively review a group of patients undergoing anterior cervical discectomy and fusion (ACDF) to determine the relative risk of adjacent level disc degeneration after incorrect needle localization. Summary of Background Data. The needle puncture technique is a well-established method to cause disc degeneration in experimental animal studies. The risk for accelerated degeneration because of needle puncture in humans is unknown. Methods. A retrospective radiographic analysis of 87 consecutive patients after single or 2-level ACDF with anterior plate instrumentation was performed. Perioperative and follow-up radiographs were used to grade disc degeneration according to a previously described scale. Results. Eighty-seven patients were included in the study (36 underwent 1-level ACDF, and 51 underwent 2-level ACDF). Seventy-two had correct needle localization at the level of planned surgery; 15 had incorrect needle localization (1 level above the operative level). There were no differences between the 2 groups in age, sex and length of follow-up. Patients in the incorrectly marked group were statistically more likely to demonstrate progressive disc degeneration with an odds ratio of 3.2. There was no correlation between age and length of follow-up with development of disc degeneration. Conclusion. There is a 3-fold increase in risk of developing adjacent level disc degeneration in incorrectly marked discs after ACDF at short-term follow-up. This may indicate that either needle related trauma or unnecessary surgical dissection contributes to accelerated adjacent segment degeneration.

Variations in surgical treatment of cervical facet dislocations.

Study Design. Retrospective Survey Analysis. Objective. To explore surgeon preference in the choice of surgical approach in the treatment of traumatic cervical facet dislocations. Summary of Background Data. The choice of surgical approach in the treatment of traumatic cervical dislocations is highly variable and maybe influenced by a variety of factors. The purpose of this study was to examine inter-rater reliability in choice of surgical approach. Methods. Twenty-five members of the Spine Trauma Study Group evaluated 10 cases of traumatic cervical dislocations. Evaluation of the case as a unilateral or bilateral injury and surgeon interpretation of the presence of a disc herniation as well as preferred surgical approach were assessed. Results. Only slight agreement was observed among surgeons in the choice of surgical approach (Kappa < 0.1). This improved slightly when patients were assumed to have a complete spinal cord injury (Kappa = 0.15). Surgeons used more anterior approaches either alone or as the first stage in a combined approach when a disc herniation was present regardless of neurologic status of the patient. When a patient was neurologically intact, an anterior approach was more common than a posterior approach even when a disc herniation was not present. Combined approaches were preferred for the treatment of bilateral facet dislocations. Conclusion. The poor agreement on the treatment of these injuries likely reflects a combination of factors including surgeon training and experience. Treatment decisions are likely to be affected by the neurologic status of the patient, interpretation of a disc herniation, and the classification of the injury as a unilateral or bilateral injury.

Risk factors for surgical site infection after posterior cervical spine surgery: an analysis of 5,441 patients from the ACS NSQIP 2005–2012

BACKGROUND CONTEXT The incidence of surgical site infection (SSI) following posterior cervical surgery has been reported as high as 18% in the literature. Few large studies have specifically examined posterior cervical procedures. PURPOSE The study aims to examine the incidence, timing, and risk factors for SSI following posterior cervical surgery. DESIGN This is a retrospective cohort study of prospectively collected data in a national surgical outcomes database. PATIENT SAMPLE The sample includes patients who underwent posterior cervical spine surgery between 2005 and 2012 identified in the American College of Surgeons National Surgical Quality Improvement Project (ACS NSQIP) Participant Use Data File. OUTCOME MEASURES The 30-day rate of postoperative SSI, timing of diagnosis, and associated risk factors were determined. METHODS The ACS NSQIP was used to identify 5,441 patients who underwent posterior cervical spine surgery by Current Procedural Terminology codes from 2005 to 2012. Thirty-day readmission data were obtained for 2011-2012. The incidence and timing of SSI were determined. Multivariable logistic regression analysis was then performed to identify significant risk factors. RESULTS Of the 5,441 patients identified as having undergone posterior cervical surgery, 3,724 had a posterior cervical decompression, 1,310 had a posterior cervical fusion, and 407 underwent cervical laminoplasty. Surgical site infection within 30 days was identified in 160 patients (2.94%), with 80 of those cases being superficial SSI. There was no significant difference in SSI rate among the three procedure groups. The average time for diagnosis of SSI was over 2 weeks. In 2011-2012, 36.9% of patients with SSI were readmitted within 30 days. Several significant predictors of SSI were identified in univariate analysis, including body mass index (BMI) >35, chronic steroid use, albumin <3, hematocrit <33, platelets <100, higher American Society of Anesthesiologists class, longer operative time, and longer hospital admission. Independent risk factors, including BMI >35 (odds ratio [OR]=1.78, p=.003), chronic steroid use (OR=1.73, p=.049), and operative time >197 minutes (OR=2.08, p=.005), were identified in multivariable analysis. CONCLUSIONS Optimization of preoperative nutritional status, serum blood cell counts, and operative efficiency may lead to a reduction in SSI rates. Obese patients and patients on chronic steroid therapy should be counseled on elevated SSI risk.

Sagittal balance and spinopelvic parameters after lateral lumbar interbody fusion for degenerative scoliosis: A case-control study

Study Design. Retrospective matched-cohort analysis. Objective. To evaluate the change in radiographical parameters in patients undergoing interbody fusion and posterior instrumentation compared with posterior spine fusion (PSF) alone for degenerative scoliosis. Summary of Background Data. Little is known about the effect of lateral interbody fusion (LIF) on sagittal plane correction in the setting of degenerative scoliosis. We performed a retrospective study to investigate these changes compared with PSF. Methods. Between 1997 and 2011, 33 patients had LIF at 181 levels between T8 and L5 vertebrae for the treatment of degenerative scoliosis (mean; 5 ± 2 levels). Of those, 23 patients had additional anterior lumbar interbody fusion (ALIF) at 37 levels between L4 and S1 vertebrae (mean; 1.6 ± 0.5 levels). A 1:1 matched control of patients who underwent PSF was performed. Patients were matched by age, sex, and diagnosis. Clinical and radiographical data were collected and compared between the matched cohorts. Results. Lumbar lordosis (LL) was significantly restored in the LIF ± ALIF compared with PSF cohort (44° ± 14° vs. 36° ± 15°, P = 0.02). The segmental LL over the 102 LIF levels significantly improved from 12°± 10° to 21°± 13° postoperatively (P < 0.0001). However, the change over the 37 ALIF levels was not significant (from 30° ± 15° to 29° ± 9°, P = 0.8). Sagittal plane alignment was improved in the LIF ± ALIF compared with PSF cohort and trended toward but did not reach significance (3.8 ± 3.2 cm vs. 6.2 ± 5.7 cm, P = 0.09). Sacral slope was significantly higher in the LIF ± ALIF compared with PSF cohort (33° ± 11° vs. 28° ± 10°, P = 0.03). Pelvic tilt was lower in the LIF ± ALIF compared with PSF cohort and trended toward but did not reach significance (22° ± 10° vs. 26° ± 10°, P = 0.08). Conclusion. LL and sacral slope had mildly but statistically improved in the interbody fusion cohort compared with PSF cohort. Sagittal alignment and pelvic tilt trended toward but did not reach statistical significance. Segmental LL was improved at LIF levels more than at ALIF levels. Level of Evidence: 3

Donor-site complications of autogenous nonvascularized fibula strut graft harvest for anterior cervical corpectomy and fusion surgery: experience with 163 consecutive cases.

BACKGROUND CONTEXT The fibula is a source of bone graft for reconstruction of the appendicular and axial skeleton. PURPOSE The aim of this study is to determine donor-site complications and morbidity in a large series of patients who underwent autogenous fibula harvesting for anterior cervical corpectomy and fusion (ACCF) surgery. STUDY DESIGN/SETTING Retrospective review (Level III). PATIENT SAMPLE One hundred sixty-three patients over an eight-year period who underwent ACCF with autogenous fibula. OUTCOME MEASURES Donor site complications (such as infection, cellulitis, pain, damage to the superficial peroneal nerve, ankle instability, tibial stress fracture, and so forth), treatment, and final outcome were determined from patient records. METHODS Retrospective study of patients who underwent ACCF with autogenous nonvascularized fibula strut graft over an eight-year period (from 1995 to 2002) was conducted. Donor site complications (such as infection, cellulitis, pain, damage to the superficial peroneal nerve, ankle instability, tibial stress fracture, and so forth), treatment, and final outcome were determined from patient records. RESULTS One hundred sixty-three patients underwent ACCF with autogenous fibula graft during the study period. The most common short-term complication (lasting <3 months) was incisional pain, present in 86 of 163 patients (53%). Incisional pain lasted longer than 3 months in 25 of 163 patients (15%) but resolved in all but two patients by 24 months. Two patients (1.2%) developed superficial peroneal neuromas. Five patients (3%) developed tibial stress fractures. Two patients (1.2%) developed ankle instability. Fifteen (9%) patients developed cellulitis that resolved in all patients after a short course of oral antibiotics, with one additional patient developing a deep infection requiring surgical debridement and intravenous antibiotics. CONCLUSIONS Although autogenous fibula is an excellent graft for multilevel ACCF reconstruction, surgeons should carefully consider the associated morbidity of fibular harvest before surgery. In this series, most complications were of short duration. However, nine patients with long-term complications required five additional surgical procedures. Therefore, patients who are scheduled to undergo autogenous fibula harvest should be advised about these potential complications.

Controversies in the treatment of cervical spine dislocations

BACKGROUND CONTEXT Cervical spine dislocations represent an area of great controversy among spine surgeons. PURPOSE The purpose of this review is to present the specific areas of controversy and to provide a review of the literature. STUDY DESIGN A case of cervical spine dislocation is presented to illustrate the major controversies related to the treatment of cervical spine dislocations. METHODS A review of the literature is presented regarding the major controversial aspects of the treatment of cervical spine dislocations. RESULTS The major areas of controversy include the choice of imaging, closed versus open reduction and surgical approach. CONCLUSIONS Guidelines for the management of cervical spine dislocations are presented based on evidence-based medicine.

The timing and influence of MRI on the management of patients with cervical facet dislocations remains highly variable: a survey of members of the Spine Trauma Study Group.

Background Traumatic cervical facet dislocations are potentially devastating injuries. Magnetic resonance imaging (MRI) is an excellent means of assessing ligamentous disruption, disk herniation, and compression of the neural elements. However, despite an improved understanding of these facet dislocations with imaging, treatment remains controversial. Purpose To survey the timing and influence of MRI on the management of patients with traumatic cervical facet dislocations. Study design Questionnaire study. Methods Clinical vignettes, plain radiographs, and computed tomography scans of 10 cases of cervical facet dislocation were presented to 25 fellowship trained spine surgeons. Participants were analyzed as to their next step in diagnosis or treatment: closed reduction, obtaining an MRI, or proceeding directly with open treatment. A revised vignette was then presented; however, on this occasion, an MRI was included with the imaging and had been obtained before a reduction attempt. Participants were then surveyed on their choice of closed or open reduction. Each of the vignettes consisted of 3 different clinical scenarios based on neurologic examination: intact, incomplete, or complete spinal cord injury. Results The interrater reliability of treatment decisions was very poor, and the reliability after MRI was available and was significantly worse when the patient was considered to have a complete spinal cord injury. After reviewing the MRI, orthopedic surgeons were significantly more likely to choose a closed versus open reduction. Neurosurgeons were significantly more likely than orthopedic surgeons to order an MRI before open or closed treatment. Conclusions The timing and utilization of MRI for patients with traumatic cervical facet dislocations remains variable. Further outcome analysis in the form of evidence-based algorithms is necessary to optimize patient management and outcomes.

Cervical Spine Injuries Associated With the Incorrect Use of Airbags in Motor Vehicle Collisions

Study Design. Retrospective database review and analysis. Objective. The purpose of this study is to determine the rate of cervical spine injuries with correct and incorrect use of front driver and passenger-side airbags. Summary of Background Data. Although there are abundant literature showing reduced injury severity and fatalities from seatbelts and airbags, no recent studies have delineated the affect of incorrect use of airbags in cervical spine injuries. Methods. The database from the Pennsylvania Trauma Systems Foundation was searched for drivers and front-seat passenger injuries from 1990 to 2002. The resulting records were then grouped into those using both seatbelt and the airbag, airbag-only, seatbelt-only, and no restraints. The data were then analyzed for frequency of cervical spine fractures with or without spinal cord injury and injury severity indexes. Results. The drivers using the airbag-only had significantly higher rate (54.1%) of cervical fractures than those using both airbag and a seatbelt (42.1%). Overall, drivers using the airbag-alone were 1.7 times more likely to suffer a cervical spine fracture than those using both protective devices. Likewise, passengers using the airbag-alone were 6.7 times more likely to suffer from a cervical spine fracture with spinal cord injury than those using both protective devices. In addition, the injury severity indexes (Glasgow coma scale, Injury Severity Score, Intensive Care Unit stays, and Total Hospital days) were significantly worse in patients who used an airbag-only. Conclusion. Airbag use without the concomitant use of a seatbelt is associated with a higher incidence of cervical spine fractures with or without spinal cord injuries. Airbag misuse is also associated with higher Injury Severity Score, lower Glasgow coma scale, and longer intensive care unit and total hospital stays, indicating that these patients suffer worse injury than those who use the airbag properly.

Biomechanical effects of anterior, posterior, and combined anterior-posterior instrumentation techniques on the stability of a multilevel cervical corpectomy construct: a finite element model analysis

BACKGROUND CONTEXT Multilevel corpectomy, with or without anterior instrumentation, has been associated with both graft and anterior screw-plate complications. The addition of posterior instrumentation after anterior fixation has been shown to increase the overall stiffness of fused segments and decrease the likelihood of instrumentation failure. Little biomechanical information exists for providing guidance in the selection of an appropriate instrumentation technique after a multilevel cervical corpectomy. Clinical studies have also been inconclusive in choosing an optimum fixation strategy. PURPOSE To test the hypothesis that combined anterior-posterior fixation would lower the stresses on the bone-screw interfaces observed after an isolated anterior fixation and on the graft-end plate interfaces observed after an isolated posterior fixation. STUDY DESIGN A finite element (FE) analysis of a C4-C7 corpectomy fusion with three different fixation techniques: anterior, posterior, and combined anterior-posterior. METHODS A previously validated three-dimensional FE model of an intact C3-T1 segment was used. From this intact model, three additional instrumentation models were constructed using anterior (rigid screw-plate), posterior (rigid screw-rod), and combined anterior-posterior fixation techniques following a C4-C7 corpectomy fusion. Construct stability at the cephalad and caudal levels of the corpectomy was assessed. RESULTS Biomechanical comparisons between these instrumentation techniques show the least amount of construct motion in the combined anterior-posterior instrumentation model. The use of both anterior and posterior fixation shields the graft-end plate and screw-bone interfaces from peak stresses as compared with an isolated anterior or an isolated posterior fixation, thereby supporting the hypothesis of this study. CONCLUSIONS A combined fixation technique should be balanced against increased operating room time and surgery costs because of dual anterior and posterior fixation and the increased risk of long anterior plating, such as dysphasia, plate or screw dislodgement, or migration. Our study suggests that the use of posterior fixation, whether alone or in combination with anterior fixation, infers comparable stability. Further studies are warranted to identify whether the current findings are consistent with other biomechanical studies.