Use of vascularized fibular grafts as a salvage procedure for previously failed spinal arthrodesis.

STUDY DESIGN: A case series of spinal arthrodesis performed with vascularized fibular grafts is presented. OBJECTIVES: The use of vascularized fibular grafts to obtain anterior spinal fusion in patients with complex spinal disorders and poor fusion environments is described. SUMMARY OF BACKGROUND DATA: The fusion success of spinal arthrodesis is dependent on numerous factors, such as the substrate used for arthrodesis (i.e., graft), the biology of the fusion bed, and local host factors. Vascularized grafts have higher success rates for union and can better overcome a poor fusion bed than nonvascular grafts. However, they are associated with higher donor site morbidity and greater technical difficulty. METHODS: Three patients with complex medical histories portending a difficult spinal fusion were treated with anterior arthrodesis using vascularized fibular autografts. Vascular patency was confirmed by bone scintigraphy, and osseous union by radiography and computed tomography. RESULTS: All patients had successful osseous fusion in 3 to 6 months. Deformity was improved. Patients reported decreased pain and resumption to previous activities at 24 months follow-up. There were no complications. CONCLUSIONS: A vascularized fibular graft is a useful alternative to standard grafts for spinal arthrodesis. Vascularized fibular grafts provide high fusion rates, rapid incorporation, and increased mechanical strength, and thus heal better in a suboptimal graft bed. The procedure is technically demanding, often requiring the expertise of a microvascular surgeon for obtaining the graft and achieving anastomosis. It is best suited in cases where significant difficulty in obtaining a spinal fusion is anticipated.

New technologies in spine: kyphoplasty and vertebroplasty for the treatment of painful osteoporotic compression fractures.

STUDY DESIGN: Literature review. OBJECTIVES: To describe new treatments for painful osteoporotic compression fractures in light of available scientific literature and clinical experience. SUMMARY OF BACKGROUND DATA: Painful vertebral osteoporotic compression fractures lead to significant morbidity and mortality. This relates to pulmonary dysfunction, eating disorders (nutritional deficits), pain, loss of independence, and mental status change (related to pain and medications). Medications to treat osteoporosis (primarily antiresorptive) do not effectively treat the pain or the fracture, and require over 1 year to reduce the degree of osteoporosis. Kyphoplasty and vertebroplasty are new techniques that help decrease the pain and improve function in fractured vertebrae. METHODS: This is a descriptive review of the background leading to vertebroplasty and kyphoplasty, a description of the techniques, a review of the literature, as well as current ongoing studies evaluating kyphoplasty. RESULTS: Both techniques have had a very high acceptance and use rate. There is 95% improvement in pain and significant improvement in function following treatment by either of these percutaneous techniques. Kyphoplasty improves height of the fractured vertebra, and improves kyphosis by over 50%, if performed within 3 months from the onset of the fracture (onset of pain). There is some height improvement, though not as marked, along with 95% clinical improvement, if the procedure is performed after 3 months. Complications occur with both and relate to cement leakage in both, and cement emboli with vertebroplasty. CONCLUSION: Kyphoplasty and vertebroplasty are safe and effective, and have a useful role in the treatment of painful osteoporotic vertebral compression fractures that do not respond to conventional treatments. Kyphoplasty offers the additional advantage of realigning the spinal column and regaining height of the fractured vertebra, which may help decrease the pulmonary, GI, and early morbidity consequences related to these fractures. Both procedures are technically demanding.

Predicting complications in elderly patients undergoing lumbar decompression.

A retrospective chart review of 68 patients 70 years of age or older who underwent decompressive procedures of the lumbar spine with or without fusion for benign conditions was performed to determine the ability of preoperative assessment of medical comorbidities to predict early postoperative complications. Patients 70 years of age or older who underwent decompressive procedures on the lumbar spine with or without fusion from January 1, 1990 to June 30, 1996 were identified. A chart review focused on preoperative comorbid diseases and early postoperative complications. A telephone survey was performed to assess patient satisfaction. Thirty-four women and 34 men with an average of 76.5 years averaged 1.6 comorbidities. Thirteen patients did not have comorbidities. The weighted comorbidity index resulted in an average score of 1.9. Eighty-five percent of the patients underwent posterolateral fusion. The total complication rate was 40%. Serious complications potentially affecting quality of life occurred in 12% of patients. The early mortality rate was 1.4%. The authors were unable to show a significant relationship between comorbidities and postoperative complications. Seventy-one percent of the 44 patients who were contacted at an average 42 months postoperatively were satisfied with their outcome. Elderly patients can safely undergo lumbar spinal procedures with an outcome similar to younger patients.

Current techniques of decompression of the lumbar spine.

Lumbar spinal decompression is a commonly performed procedure. Although the conventional open techniques of decompression remain the gold standard of treatment, problems with paraspinal musculature denervation and resultant lumbar instability have focused attention on less invasive techniques. A multitude of spinal instrumentation systems have been developed to stabilize the spine and improve arthrodesis rates. A stronger emphasis on restoration of anterior column height and stability has increased the use of anterior interbody fusion devices. Developing technology is allowing for better visualization and possibly improved outcomes with minimally-invasive techniques. The results of all lumbar decompressive and stabilization procedures however, remain closely related to careful patient selection.

The significance of thoracolumbar spinal canal size in spinal cord injury patients.

STUDY DESIGN: A prospective, consecutive case series. OBJECTIVES: To determine the relation between spinal canal dimensions and Injury Severity Score and their association with neurologic sequelae after thoracolumbar junction burst fracture. SUMMARY OF BACKGROUND DATA: There is a relation in the cervical spine between spinal canal dimension and its association with neurologic sequelae after trauma. A similar relation at the thoracolumbar junction has not been conclusively established. METHODS: Forty-three patients with thoracolumbar junction burst fractures (T12-L2),13 with and 30 without neurologic deficit, were included. Computed tomographic scans were used to measure the sagittal and transverse diameters and the surface area of the spinal canal at the level of injury, as well as one level above and one level below the fracture level. Injury severity score was calculated for both groups. Statistical analysis comparing those with a neurologic deficit to those without was performed by Student's t test. RESULTS: The ratio of sagittal-to-transverse diameter at the level of injury was significantly smaller in patients with a neurologic deficit than in those without a neurologic deficit (P < 0.05). The mean transverse diameter at the level of injury was significantly larger in patients with neurologic deficit than in the neurologically intact patients (P < 0.05). The surface area of the canal at the level below the injury was significantly larger in the patients with a neurologic deficit than in those without a deficit (P < 0.05). Patients with a neurologic deficit had a statistically higher Injury Severity Score when admitted than those without a neurologic deficit (P < 0.0001), although the difference became insignificant after the neurologic component of the scoring system was eliminated. CONCLUSION: There are no anatomic factors at the thoracolumbar junction that predispose to neurologic injury after burst fracture. The shape of the canal after injury, however, as determined by the sagittal-to-transverse diameter ratio, was predictive of neurologic deficit.

Effect of surgical cricothyrotomy on the unstable cervical spine in a cadaver model of intubation.

Cricothyrotomy is indicated for patients who require an immediate airway and in whom orotracheal or nasotracheal intubation is unsuccessful or contraindicated. Cricothyrotomy is considered safe with cervical spine (c-spine) injury; however, the amount of c-spine movement that occurs during the procedure has not been determined. In this experimental study, an established cadaver model of c-spine injury was used to quantify movement during cricothyrotomy. A complete C5--6 transection was performed by using an osteotome on 13 fresh-frozen cadavers. Standard open cricothyrotomy was performed on each cadaver, with c-spine images recorded in real time on fluoroscopy, then transferred to video and Kodachrome still images. Outcome measures included movement across the C5--6 site with regard to angulation expressed in degrees of rotation and linear measures of axial distraction and anterior-posterior (AP) displacement expressed as a proportion of C5 body width. Data were analyzed by using descriptive statistics to determine mean change from baseline in each of three planes of movement. Significance was assumed if 95% confidence intervals did not include zero. A significant amount of movement was observed with regard to AP displacement (6.3% of C5 width) and axial distraction (-4.5% of C5 width, indicating narrowing of the intervertebral space). These correspond to 1--2 mm AP displacement and less than 1 mm axial compression. No significant angular displacement was observed. In conclusion, cricothyrotomy results in a small but significant amount of movement across an unstable c-spine injury in a cadaver model. This degree of movement is less than the threshold for clinical significance.

Effects of cervical spine immobilization technique and laryngoscope blade selection on an unstable cervical spine in a cadaver model of intubation.

STUDY OBJECTIVE: Orotracheal intubation (OTI) is commonly used to establish a definitive airway in major trauma victims, with several different cervical spine immobilization techniques and laryngoscope blade types used. This experimental, randomized, crossover trial evaluated the effects of manual in-line stabilization and cervical collar immobilization and 3 different laryngoscope blades on cervical spine movement during OTI in a cadaver model of cervical spine injury. METHODS: A complete C5-C6 transection was performed by using an osteotome on 14 fresh-frozen cadavers. OTI was performed in a randomized crossover fashion by using both immobilization techniques and each of 3 laryngoscope blades: the Miller straight blade, the Macintosh curved blade, and the Corazelli-London-McCoy hinged blade. Intubations were recorded in real time on fluoroscopy and then transferred to video and color still images. Outcome measures included movement across C5-C6 with regard to angulation expressed in degrees of rotation and axial distraction and anteroposterior displacement with values expressed as a proportion of C5 body width. Cormack-Lehane visualization grades were also recorded as a secondary outcome measure. Data were analyzed by using multivariate analysis of variance to test for differences between immobilization techniques and between laryngoscope blades and to detect for interactions. Significance was assumed for P values of less than.05. RESULTS: Manual in-line stabilization resulted in significantly less movement than cervical collar immobilization during OTI with regard to anteroposterior displacement. Use of the Miller straight blade resulted in significantly less movement than each of the other 2 blades with regard to axial distraction. The Cormack-Lehane grade was significantly better with manual in-line stabilization versus cervical collar immobilization; no differences were observed between blades. CONCLUSION: Manual in-line stabilization results in less cervical subluxation and allows better vocal cord visualization during OTI in a cadaver model of cervical spine injury. The Miller laryngoscope blade allowed less axial distraction than the Macintosh or Corzelli-London-McCoy blades. The clinical significance of this degree of movement is unclear.

Anatomic and biomechanical analysis of the lower lumbar foraminal ligaments.

STUDY DESIGN: An anatomic cadaveric study to characterize the lumbar intraforaminal nerve root attachments. OBJECTIVES: To characterize the intraforaminal nerve root attachments and describe their anatomic relationships and biomechanical properties. SUMMARY OF BACKGROUND DATA: Observations during foraminotomies for lateral recess stenosis as well as lateral approaches for far lateral disc herniation have shown dense attachments between the nerve root and adjacent structures. Little or no information has appeared in the literature describing intraforaminal nerve root attachments. METHODS: Twelve fresh-frozen human cadaveric lumbar spines were used to study intraforaminal ligamentous structures. Four cadavers were cut into sagittal sections for qualitative description, and eight were used for biomechanical testing. Histologic analyses were performed on samples of the foraminal attachments to assure that they were not vascular or neural structures. Biomechanical testing of the nerve roots with ligamentous attachments was performed measuring load to failure along the anatomic axis of the root. RESULTS: The dissections showed four distinct bands extending radially from the nerve root sleeve. The most prominent nerve root attachment was to the facet capsule posteriorly. Other ligaments fanned out with attachments inferiorly and superiorly to the adjacent pedicles and anteriorly to the intervertebral disc. Biomechanical study of the L3, L4, and L5 nerve roots showed a significant increase in strength at failure with axial traction, progressing from L3 to L5. CONCLUSIONS: The results demonstrate that these foraminal ligaments are normal anatomic structures within the intervertebral foramen of the lumbar spine. In addition, they may play a role in limiting motion along the nerve root.

Spine update: cervical spine internal fixation using screw and screw-plate constructs.

Screw and screw-plate constructs have been used successfully in fixation of the cervical spine. This update focuses on the indications, complications, and nuances in the technique used for odontoid screws, transarticular C1-C2 screws, occipitocervical plating, posterior lateral mass screws, pedicle screws, and anterior plating.

Anterior C1-C2 screw fixation and bony fusion through an anterior retropharyngeal approach.

We present a case that demonstrates an occasion where an alternative method of C1-C2 fusion may be used when a posterior approach limited to the atlantoaxial level is not desirable. A 22-year-old man presented with a symptomatic nonunited Brooks posterior atlantoaxial fusion following a chronically displaced type II odontoid fracture with a two-part fracture of the posterior arch of C1. An anterior retropharyngeal approach was used to perform an anterior C1-C2 fusion with screw fixation. The surgical technique, as well as the merits and indications of this infrequently used procedure, are discussed.

Stabilizing potential of anterior cervical plates in multilevel corpectomies.

STUDY DESIGN: An in vitro investigation of three-dimensional kinematics of cervical spine models of one- and three-level corpectomy with anterior plate fixation. OBJECTIVES: To evaluate the capability of an anterior plate to stabilize the reconstructed cervical spine under simulated physiologic motions, and to study the effects of fatigue loading. SUMMARY OF BACKGROUND DATA: Clinical studies have found high failure rates of multilevel anterior cervical plate fusions, indicating suboptimal stabilization. However, no biomechanical studies have been done to investigate the stabilizing capabilities of long-plate instrumentations in corpectomy models. METHODS: Seven fresh human cadaveric cervical spine specimens (C2-T1) were used. Flexibility tests consisted of flexion, extension, and bilateral torsion, and lateral bending, each with a pure moment of 0.25, 0.5, 0.75, and 1.0 Nm. Stabilizing potential indices [(MotionIntact-MotionInstrumented)/MotionIntact] for ranges of motion and neutral zones obtained from the flexibility tests, were measured when the specimen was intact and after one-level (C5) and three-level (C4, C5, and C6) corpectomies and anterior plate stabilizations). The stabilizing potential indices were re-measured after a 1000-cycle fatigue loading (1 Nm flexion and extension moments at C5 vertebra at 0.14 Hz). RESULTS: The differences in stabilizing potential indices of range of motion and neutral zone between one-level and three-level plates were not significant before fatigue. However, after fatigue, the stabilizing potential indices significantly decreased (P < 0.05) for the three-level model, but not for the one-level plate model. CONCLUSIONS: The capability of an anterior cervical plate to stabilize the spine after three-level corpectomy was significantly reduced with fatigue loading.

Effects of noradrenergic and serotonergic antidepressants on chronic low back pain intensity.

To understand the relative efficacy of noradrenergic and serotonergic antidepressants as analgesics in chronic back pain without depression, we conducted a randomized, double-blind, placebo-control head-to-head comparison of maprotiline (a norepinephrine reuptake blocker) and paroxetine (a serotonin reuptake blocker) in 103 patients with chronic low back pain. Of these 74 completed the trial; of the 29 who did not complete, 19 were withdrawn because of adverse effects. The intervention consisted of an 8-week course of maprotiline (up to 150 mg daily) or paroxetine (up to 30 mg daily) or an active placebo, diphenhydramine hydrochloride (up to 37.5 mg daily). Patients were excluded for current major depression. Reduction in pain intensity (Descriptor Differential Scale scores) was significantly greater for study completers randomized to maprotiline compared to placebo (P=0.023), and to paroxetine (P=0.013), with a reduction of pain by 45% compared to 27% on placebo and 26% on paroxetine. These results suggest that at standard dosages noradrenergic agents may provide more effective analgesia in back pain than do selective serotonergic reuptake inhibitors.

Symptomatic pseudarthrosis of the acromion: report of a case and review of the literature.

The case of a twenty-three-year-old male with a symptomatic pseudarthrosis of the acromion is presented. Open reduction and internal fixation with a plate, screw, and tension band construct supplemented with a bone graft was performed and early range of motion was initiated. Nine months after surgery, the fracture was healed and the patient had excellent function of the shoulder. The literature on pseudarthrosis of the acromion is reviewed.

Early failure of long segment anterior cervical plate fixation.

A retrospective, multicenter study was undertaken to evaluate the early postoperative failure rate of long segment anterior cervical fusion and plating to stabilize the cervical spine after a two- or three-level corpectomy for degenerative, traumatic, and neoplastic diseases of the cervical spine. Patient demographic factors as well as technical factors such as bone graft placement, plate and screw position, and postoperative brace immobilization were analyzed. During the early postoperative period, the graft/plate construct dislodged in 3 of 33 patients with a two-level corpectomy and fusion (9%) compared with 6 of 12 patients with a three-level corpectomy and fusion (50%). The difference in failure rates after a three- versus two-level corpectomy and fusion was statistically significant (p < 0.05). A higher early failure rate was also seen with failure to correctly lock the screws to the plate and the use of a peg-in-hole type bone grafting technique, although these differences were not statistically significant. Although several technical and patient-specific factors may contribute to this, anterior cervical plating and bone grafting alone after a three-level cervical corpectomy for various spinal disorders appears to afford inadequate stability in the early postoperative period, regardless of immobilization methods.