Jeffery L. Stambough

Postoperative Wound Infections Complicating Adult Spine Surgery

A review of 19 consecutive patients treated for deep wound infections after spinal surgery was performed. Patients were analyzed for preoperative risk factors, original diagnosis requiring surgery, onset of infection, presentation, treatment, and outcome. These patients (10 men, nine women), with a mean age of 44 years (range 18-74) were treated for 13 deep and six subcutaneous infections: 16 spine infections and nine graft site infections (six with both). All 19 presented with draining wounds on an average of 17 days after surgery (range 4-86). Staphylococcus aureus was cultured in 14. Patients were treated with i.v. antibiotics for an average of 3 weeks (range 0-14) followed by oral antibiotics for an average of 6 weeks (range 2-12). Surgical treatment included an average of 1.8 debridements (range 0-5), primary closure in two, delayed primary closure in seven, and healing by secondary intent in 10. All but three patients were noted to be malnourished at the onset of their infection, with a total lymphocyte count of less than 2,000. Three patients required removal of their hardware. Eighteen of 19 healed or their infections were stabilized, 17 of 18 arthrodeses fused, and no patient had neurological deterioration secondary to the infection. The treatment outlined produced satisfactory results in all but one patient. We conclude that postoperative spine infections are frequently associated with poor nutrition. Although definitive diagnosis is determined by the culture, clinical exam is helpful in establishing a presumptive diagnosis and, thus, earlier institution of surgical and antibiotic treatment.

Ophthalmologic complications associated with prone positioning in spine surgery.

Abstract Visual impairment and blindness associated with general anesthesia and prone positioning in spine surgery have been increasing in incidence over the past several decades. Corneal abrasion, the most common ophthalmologic injury, is usually selflimiting. However, prolonged surgical procedures (>7 hours) associated with acute blood loss anemia, hypotension, and hypoxia may lead to posterior ischemic optic neuropathies. Direct pressure to the periorbital region of the eye can cause increased intraocular pressure and blindness as the result of central retinal artery occlusion. Hypoxia and cerebral embolism are associated with occipital cortical infarct or cortical blindness. The prognosis for visual recovery from ischemic neuropathy and retinal artery occlusion is poor. Cortical blindness usually improves to varying degrees. Effective treatment of perioperative amaurosis is lacking and usually ineffective, making prevention the cornerstone of management. To best prevent permanent ophthalmologic complications associated with prone positioning during spine surgery, orthopaedic surgeons should be aware of pathophysiology and related risks associated with spine surgery in the prone position, and initiate preventive measures and predictable treatment options.

Critical analysis of strut grafts in anterior spinal fusions

Fifty patients undergoing anterior spinal decompression with partial or complete corpectomy and fusion with strut grafting were reviewed. The etiology of the spinal lesions included pathologic fracture (9 patients), trauma (22 patients), congenital/developmental lesions (6 patients), failed fusion (6 patients), and degenerative lesions (7 patients). Vertebral body reconstruction of the cervical, thoracic, or lumbar spine used iliac crest (20 cases), rib (12 cases), and fibular autografts (9 cases). Additionally, in 10 cases fibular allografts were used. There were four deaths, all secondary to systemic disease. Of the remaining 46 patients, 2 required revisions and all subsequently progressed to a solid anterior arthrodesis with an average follow-up of 30.4 months (range 12-62 months). Posterior spinal fusion was staged in 38 patients. Twenty of 29 patients with neurologic lesions improved after corpectomy. Eleven cases treated for a progressive, painful kyphosis averaged correction of 11.4 degrees (26%), which was maintained on long-term follow-up. Complications were primarily pulmonary and/or genitourinary. Others included a pseudarthrosis, an early fractured strut, and a late allograft infection. On the basis of this review, it appears that spinal arthrodesis with anterior decompression and strut grafting is an effective method of treating anterior compressive syndromes of the spine and painful progressive kyphoses.

Somatosensory Cortical Evoked Potentials: A Review of 100 Cases of Intraoperative Spinal Surgery Monitoring

A review of our experience with evoked potential monitoring of over 100 spinal procedures is summarized here. Typical results of somatosensory cortical evoked potential (SCEP) testing found that latency of responses increased slightly and amplitude decreased substantially from preanesthesia to predistraction with no further changes. SCEP results are effected by many factors, but when they are understood and recognized, evoked potential monitoring can play a significant role in recognizing potential problems and preventing postoperative neurological problems in patients undergoing spinal surgery.

Nonglucocorticoid-induced lumbar epidural lipomatosis: a case report and review of literature.

A case of nonglucocorticoid-induced lumbar epidural lipomatosis in a middle-aged black woman with neurogenic claudication is presented. The etiology, diagnosis, management, and outcome are discussed in detail.

Delayed postoperative epidural hematoma formation after heparinization in lumbar spinal surgery.

Treatment of thromboembolic disease in the postoperative lumbar spine patient is controversial. This case report describes an epidural hematoma with neurologic sequelae in an elderly patient who received intravenous heparin therapy over 2 weeks after lumbar decompression. Implications for treatment of thromboembolic disease in the postoperative lumbar spine is reviewed.

Lumbar disk herniation : An analysis of 175 surgically treated cases

This is a retrospective review of 175 consecutive open lumbar diskectomies with a minimum 1-year follow-up (average follow-up, 54 months). Results of the diskectomies were: 91.0% good-to-excellent result, 3.4% fair, and 1.1% poor. Complications were few, and the overall recurrence rate was 4.6%. By multiple linear regression analysis, no one factor could predict the relief of leg pain.

Biomechanical assessment of titanium and stainless steel posterior spinal constructs : Effects of absolute/relative loading and frequency on fatigue life and determination of failure modes

The goal of this study was to examine the effects of absolute/relative loads and frequency on the fatigue life of titanium and stainless steel posterior spinal constructs, and to determine the failure fracture modes. The stainless steel constructs had higher stiffness and yield strength than the titanium constructs, but the ultimate static strength was almost equal for both types of constructs. Titanium constructs, however, exhibited higher variability than the stainless steel constructs. In fatigue tests, the stainless steel constructs were significantly affected by the external load and were frequency independent. It appears from fatigue curves that 500 N can be approximated as the endurance limit for the stainless steel constructs. Titanium constructs were load-frequency dependent, and their endurance limit was somewhere between the 500 and 750 N load levels. There were no differences in performance between the stainless steel and titanium constructs at 16 Hz. At 4 Hz, titanium constructs performed as well or better than stainless steel constructs. Also, the titanium constructs resulted in better performance than the stainless steel constructs in the elastic region, and with smaller differences in the plastic region. Most of the failure modes for stainless steel constructs were in screw bending at 16 Hz with a smaller percentage of rod fractures at high loads, with a higher percentage of rod fractures observed for the stainless steel constructs at 4 Hz. Most of the failure modes for titanium constructs occurred in screw bending or fracture.

Lumbosacral instrumented fusion : Analysis of 124 consecutive cases

One hundred twenty-four cases of lumbosacral fusion receiving transpedicular screw fixation were divided into two groups and reviewed retrospectively. The conditions treated include spondylolisthesis, scoliosis, tumor, trauma, and degenerative disc disease. There were 83 males and 41 females in this consecutive series averaging a 45.2-month follow-up. The primary or first-time arthrodesis rate was 91.9%. A learning curve effect as it relates to operative time but not pedicular screw placement was shown. Instrumentation-related and general medical and surgical complications were low. Infection rates were also low; superficial 2.4%, deep 1.6%. Nonunion or delayed union was salvaged in 10 cases, improving the overall fusion rate to 97.6%. The results of this study support the use of lumbosacral transpedicular screw fixation in select spinal conditions.

Central retinal artery occlusion : a complication of the knee-chest position

A rare complication of the knee-chest position used for lumbar disk surgery is reported. Central retinal artery occlusion resulted in permanent loss of vision secondary to direct ocular pressure. Prevention is the only rational treatment for this unfortunate condition.