William F. Young

An early comparative analysis of the use of fibular allograft versus autologous iliac crest graft for interbody fusion after anterior cervical discectomy

During a 2-year period (1988-1989), 23 cases of anterior cervical discectomy were performed with cadaveric fibular allograft instead of autologous iliac crest graft. The mean age of the patients was 35 years. There were 10 men and 13 women. In most cases, a one-level fusion was performed at the C5-6 level. The Smith-Robinson technique was used for discectomy and fusion, for both one- and two-level fusions. Evidence of radiographic fusion was achieved in 92% of the cases. Twenty-five cases of anterior cervical discectomy in which autologous iliac crest graft was used (1987-1988) were examined retrospectively for comparison. The mean duration of hospital stay was less in the allograft group (5.4 days vs. 7.25 days). In addition, postoperative pain was less in the allograft group because the allograft group did not have pain from the donor site. In conclusion, the use of fibular allograft for interbody fusion after anterior cervical discectomy can be performed with acceptable rates of fusion and less postoperative pain, as compared to the use of autologous iliac crest graft.

A comparative study of MR imaging profile of titanium pedicle screws

Objective: We compared the MR imaging profile of three different types of titanium pedicle screw implants in common usage in a human cadaveric model. We additionally compared the change in temperature during imaging among three constructs. Material and Methods: Titanium-based lumbar pedicle screw/rod constructs from three manufacturers were implanted sequentially in a human cadaveric spine. MR imaging was then performed using both conventional spin-echo sequences and advanced imaging pulse sequences. Changes in tissue temperature were also measured during imaging to assess differences among the various implants. MR images were compared in a blinded fashion by two neuroradiologists. Results: No significant differences in imaging profile were noted between the three types of titanium implants with regards to their MR artifact profile. Fast spin-echo sequences led to a decrease in perceptible MR artifacts. Moreover, there were no significant differences in temperature increase among the three manufacturers (mean increase 0.5°C) during imaging. Conclusion: Slight differences in the percentage of titanium among the three pedicle screw systems does not appear to result in artifact differences during MR imaging. Therefore, with regard to imaging profile considerations, the three systems studied should be considered interchangeable.

Dysphagia, hoarseness, and unilateral true vocal fold motion impairment following anterior cervical diskectomy and fusion.

The charts of 100 patients who underwent anterior cervical diskectomy with fusion performed at our institution between January 1996 and February 1999 were reviewed. The incidences of hoarseness, dysphagia, and unilateral true vocal fold motion impairment were calculated. Univariate logistic regression was used to estimate the relationship of several patient and technical factors to the rates of occurrence of hoarseness and dysphagia. Patient age was found to be a significant predictor of postoperative dysphagia (p < .006), with an odds ratio of 1.113 (95% confidence limits, 1.04, 1.21) per year of age. Other factors studied were not found to be significant predictors. The overall incidence of these complications from the world literature was also calculated. The overall incidences of dysphagia, hoarseness, and unilateral true vocal fold motion impairment in the literature were calculated as 12.3%, 4.9%, and 1.4%, respectively. We conclude that dysphagia, hoarseness, and unilateral vocal fold motion impairment continue to remain significant complications of anterior cervical diskectomy with fusion. Older patients may be at higher risk for dysphagia.

Complement Depletion Improves Neurological Function in Cerebral Ischemia

The contribution of the complement system to the exacerbation of cerebral ischemia/reperfusion injury was studied by comparing a group of rats with normal complement levels to another group that was complement depleted by cobra venom factor (CVF). The magnitude of reactive hyperemia was significantly greater in the complement depleted animals. There was also better preservation of somatosensory evoked potentials (SSEPs) in the complement depleted animals. These differences were not associated with changes in leukocyte infiltration as evidenced by myeloperoxidase and Leukotriene B4 activity. These data demonstrate that depleting the complement system can improve flow and outcome following cerebral ischemia with reperfusion.

Diagnosis and Management of Occipital Condyle Fractures

The authors recently treated three cases involving fractures of the occipital condyle. First described by Bell in 1817, this lesion has proven to be very rare, with only 32 cases previously reported in the literature. Plain films often do not reveal any abnormality, making diagnosis difficult. High-resolution computed tomography has been demonstrated to be very sensitive in diagnosing this lesion. This fact was borne out in the authors series. All of the authors patients were managed either with a Philadelphia collar or with halo fixation, with excellent outcomes.

Spinal epidural hematoma associated with tissue plasminogen activator treatment of acute myocardial infarction

We report a case of tissue plasminogen activator‐associated spinal epidural hematoma in a patient who underwent treatment for myocardial infarction. Diagnostic magnetic resonance imaging was used within 24 hr of coronary artery stent implantation. We review the literature on thrombolytic‐associated epidural spinal hematoma and discuss its management. Cathet. Cardiovasc. Intervent. 48:390–396, 1999.

Coadministration of methylprednisolone with hypertonic saline solution improves overall neurological function and survival rates in a chronic model of spinal cord injury

OBJECTIVE We previously demonstrated that administration of 7.5% hypertonic saline (HS) significantly improved spinal cord blood flow and neurological outcomes after spinal cord injury. The aim of this study was to determine whether hypertonicity would enhance the effects of methylprednisolone (MP), further improving neurological function. METHODS Rat spinal cords were compressed for 10 minutes with 50 g of weight, and neurological function was assessed for 28 days, using the Basso-Beattie-Bresnahan locomotor rating scale. The control group received an intravenous injection of isotonic saline (IS) (5 ml/kg). Group 1 received an intravenous injection of 7.5% HS (5 ml/kg). Group 2 received an intravenous injection of MP (30 mg/kg) and IS (5 ml/kg). Group 3 received an intravenous injection of MP (30 mg/kg) administered with 7.5% HS (5 ml/kg). RESULTS At 24 hours after spinal cord injury, the combination of MP plus HS provided significant (P < 0.01) neurological improvements, compared with all other treatment groups. At 10 days after injury, the animals that had received MP plus HS exhibited significantly (P < 0.01) higher Basso-Beattie-Bresnahan scores, compared with the MP plus IS and control groups. The median survival time was significantly (P < 0.01) increased for the MP plus HS group (28 d), compared with the MP plus IS group (16 d). Because of the dramatic decrease in survival rates at 28 days after injury, there was a significant (P < 0.01) difference in neurological function only between the MP plus HS group and the control group. CONCLUSION The results indicate that the administration of HS may enhance the delivery of MP and prevent immunosuppression, leading to improvements in overall neurological function and survival rates after spinal cord injury.

Isolated Pyogenic Osteomyelitis of the Odontoid Process

A case of isolated pyogenic osteomyelitis of the odontoid process is reported. Diagnosis was made using magnetic resonance imaging. Aggressive treatment, including transoral drainage of the abscess, antibiotics and cervical immobilization, resulted in a successful outcome. A review of the worlds literature revealed only 15 previous reports of this rare entity.

Ruptured cerebral aneurysm in a 39-day-old infant

A case of middle cerebral artery aneurysm in a 39-day-old infant is discussed. The unique characteristics of aneurysms in the pediatric age group which distinguish them from adults are male predominance, greater frequency in middle cerebral artery and posterior circulation. In addition, they demonstrate a greater frequency of large and giant aneurysms. Theories on the etiology of cerebral aneurysms in children are discussed.

The effects of hypertonic saline on spinal cord blood flow following compression injury.

Summaryu20037.5% hypertonic saline was administered following spinal cord injury to test its effect on spinal cord blood flow. Four different groups of rats underwent 10 minutes of spinal cord compression (45g) at the C3 to C5 levels. A fifth group was not injured, but received hypertonic saline (5 ml/kg) at 5, 15 and 60 minutes following injury. Somatosensory evoked potentials and spinal cord blood flow were measured prior to and for 4 hours following the injury. The administration of hypertonic saline caused a significant increase in flow when administered 5 minutes following injury. Topical nitroprusside administration did not cause any increase in spinal cord blood flow during this time period. Hypertonic saline administration at the later time periods did not increase spinal cord blood flow. The group of animals which were not injured, but received hypertonic saline also showed no significant change in flow. The somatosensory evoked response of the treated animals was maintained for 4 hours after the injury where as the untreated animals began to lose their evoked responses 3 hours after injury.