Rolando M. Puno

Perioperative Complications of Posterior Lumbar Decompression and Arthrodesis in Older Adults

BACKGROUND Lumbar arthrodesis is commonly done in elderly patients to treat degenerative spine problems. These patients may be at increased risk for complications because of their age and associated medical conditions. In this study, we examined the rates of perioperative complications associated with posterior lumbar decompression and arthrodesis in patients sixty-five years of age or older. METHODS We reviewed the hospital records of ninety-eight patients who were sixty-five years of age or older when they had a posterior decompression and lumbar arthrodesis with instrumentation, between 1993 and 1995, to treat degenerative disease of the spine. The average age was seventy-two years (range, sixty-five to eighty-four years). RESULTS Perioperative complications occurred in seventy-eight patients. Twenty-one patients had at least one major complication, and sixty-nine had at least one minor complication. Forty-nine patients had more than one complication. The most common major complication was wound infection (prevalence, 10%), and the most common minor complication was urinary tract infection (prevalence, 34%). The complication rate increased with older age, increased blood loss, longer operative time, and the number of levels of the arthrodesis. CONCLUSIONS Surgeons should be vigilant about perioperative complications in elderly patients treated with multi-level lumbar decompression and arthrodesis with instrumentation. Elderly patients should be made aware that they are at increased risk for surgical complications because of their age. Attention should be paid to controlling blood loss and limiting operative time.

The effect of postoperative nonsteroidal anti-inflammatory drug administration on spinal fusion.

Study Design. The influence of ketorolac on spinal fusion was studied in a retrospective review of 288 patients who underwent an instrumented spinal fusion. Objective. To assess the effect of postoperative ketorolac administration on subsequent fusion rates. Summary of Background Data. Nonsteroidal anti‐inflammatory drugs are widely used compounds, which are known to inhibit osteogenic activity and have been shown to decrease spinal fusion in an animal model. No previous studies have examined the influence of nonsteroidal anti‐inflammatory drugs on spinal fusion in clinical practice. Methods. The medical records of 288 patients who underwent instrumented spinal fusion from L4 to the sacrum between 1991 and 1993 were reviewed retrospectively. The 121 patients who received no nonsteroidal anti‐inflammatory drugs were compared with the 167 patients who received ketorolac after surgery. The groups were demographically equivalent. Results. Ketorolac had a significant adverse effect on fusion, with five nonunions in the nondrug group and 29 nonunions in the ketorolac group (P > 0.001). Ketorolac administration also significantly decreased the fusion rate for subgroups including men, women, smokers, and nonsmokers. The odds ratio demonstrated that nonunion was approximately five times more likely after ketorolac administration. Cigarette smoking also decreased the fusion rate (P > 0.01); smokers were 2.8 times more likely to develop nonunion. Conclusion. These data suggest that nonsteroidal anti‐inflammatory drugs significantly inhibit spinal fusion at doses typically used for postoperative pain control. The authors recommend that these drugs be avoided in the early postoperative period.

Perioperative complications of anterior procedures on the spine.

We reviewed the operative and hospital records of 447 patients in order to determine the rates of perioperative complications associated with an anterior procedure on the thoracic, thoracolumbar, or lumbar spine. The anterior procedures were performed to treat spinal deformity or for débridement or decompression of the spinal canal. The diagnostic groups that we studied included idiopathic scoliosis in adolescents or young adults (100 patients), scoliosis in mature adults (sixty-three patients), kyphosis (sixty-one patients), neuromuscular scoliosis (sixty patients), fracture (forty-seven patients), a revision procedure (thirty-nine patients), congenital scoliosis (thirty-six patients), tumor (nineteen patients), vertebral osteomyelitis or discitis (eight patients), and miscellaneous (fourteen patients). Complications occurred in 140 (31 per cent) of the 447 patients and were classified as major or minor. Forty-seven patients (11 per cent) had at least one major complication and 109 (24 per cent) had at least one minor complication. Two patients died, both from pulmonary complications after the operation. The most common type of major complication was pulmonary; the most common type of minor complication was genito-urinary. The adolescent or young adult patients who had idiopathic scoliosis had the lowest rate of complications, and the patients who had neuromuscular scoliosis had the highest. An age of more than sixty years at the time of the operation was associated with a higher risk of complications. The duration of the procedures involving a thoracic approach was shorter than that of those involving a thoracolumbar or lumbar approach; however, the rate of complications was not significantly different among the three approaches. Vertebrectomies took longer to perform and were associated with a greater estimated blood loss than discectomies; however, there was no significant difference in the rate of complications between the two types of procedures. The patients who had a fracture or a tumor lost more blood than those from the other diagnostic groups. Blood loss increased as the duration of the operation increased for all procedures. Combined anterior and posterior procedures performed during the same anesthesia session were associated with a higher rate of major complications than were procedures that were staged. A logistical regression analysis showed that the variables that increased the risk of a major complication were an estimated blood loss of more than 520 milliliters and an anterior and posterior procedure performed sequentially under the same anesthesia session. This analysis also demonstrated that the diagnosis of idiopathic scoliosis in adolescents or young adults was associated with a reduced risk of major complications. Compared with other major operations, an anterior procedure on the thoracic, thoracolumbar, or lumbar spine performed for the indications mentioned in this study is relatively safe.

Salvage of Instrumented Lumbar Fusions Complicated by Surgical Wound Infection

Study Design This study retrospectively reviewed instrumented lumbar fusions complicated by surgical wound infection and managed by a protocol including antibiotic impregnated beads. Objective To evaluate the potential for an acceptable clinical outcome in cases of instrumented lumbar fusion complicated by wound infection. Summary of Background Data Initial studies of pedicle screw instrumentation suggested an increased infection rate versus noninstrumented fusion. The presence of a metallic implant also complicates wound management. Methods Eight hundred fifty‐eight instrumented fusions were reviewed with 22 (2.6%) deep wound infections identified. Analysis included preoperative risk factors, surgical procedure, postoperative course, and clinical outcome. Results Nineteen patients (mean age, 55 years) were reviewed at a minimum of 1 year after surgery. Sixteen (83%) reported significant preoperative health problems. Forty‐seven percent of the patients had three‐ and four‐level fusions. Mean operative time was 342 minutes. Mean estimated blood loss was 1620 mL. Infection was diagnosed at an average of 16 days after surgery with wound drainage as the most common presenting feature. Patients underwent between two and 10 (mean, 4.7) irrigation procedures. Seven patients had other significant noninfectious complications. At follow‐up evaluation, no patient had recurrence of infection. By comparison to preoperative symptoms, 15 patients were improved, three were unchanged, and one deteriorated. Fusion was apparently solid in 14 patients, probable in four patients, and nonunion occurred in one patient. Conclusion Although wound infection is a significant complication, this study suggests that aggressive surgical management can result in preservation of an adequate fusion rate and maintenance of an acceptable postoperative outcome.

A prospective analysis of intraoperative electromyographic monitoring of pedicle screw placement with computed tomographic scan confirmation

Study Design This study analyzed clinical characteristics of scoliosis associated with congenital heart disease. Chest roentgenograms were reviewed to determine frequency, type, onset, and progression of scoliosis associated with congenital heart disease. Objectives To determine which patients with scoliosis and congenital heart disease should be followed-up carefully. Summary of Background Data Although several studies have been reported on scoliosis and congenital heart disease, the etiology of scoliosis in patients with congenital heart disease is still unknown. Furthermore, it has been difficult to determine the progression of scoliosis. Methods Chest roentgenograms of 680 patients who underwent cardiac operations because of congenital heart disease were evaluated. Results Seventy-four (10.9%) of these patients had scoliosis of more than 10°, although most of them had mild curves. Scoliosis in patients under 10 years old undergoing cardiac operations was more severe than in those older than 10 years who underwent surgery. Scoliosis associated with congenital heart disease showed no particular features. Patients with patent ductus arteriosus showed left convex, high thoracic scoliosis after surgery. Conclusions The mechanisms of onset of scoliosis in patients with congenital heart disease were not simple and were affected by several factors, including age at operation, side of approach, and type of congenital heart disease.Study design. In a prospective study of 90 patients undergoing lumbar pedicle screw instrumentation, 512 screws were tested intraoperatively using electrical stimulation. The accuracy of this technique was verified after surgery by computed tomography. Objectives. Computed tomographic scans taken after surgery were used to evaluate the efficacy of intraoperative screw stimulation and electromyographic monitoring of pedicle screw placement. Summary of Background Data. Previous cadaveric and clinical studies showed the risk of pedicle screw malposition and the inadequate reliability of intraoperative radiographs to identify misplaced screws. Methods. Screws (total, 512) in 90 patients were stimulated intraoperatively, and stimulation threshold was recorded. Computed tomographic scans were taken after surgery to document pedicle screw position. Electromyographic thresholds and computed tomographic data were evaluated independently and compared to assess the accuracy of the electromyographic screw stimulation technique. Results. Intraoperative screw stimulation was extremely accurate in confirming the adequacy of screw position. A stimulation threshold greater than 15 mA provided a 98% confidence that the screw was within the pedicle. In eight of 90 patients (9%), electromyographic monitoring detected a screw malposition that was not identified on lateral radiograph. Conclusions. Screw stimulation monitoring is a valuable and efficacious adjunct to lumbar pedicle screw instrumentation. A stimulation threshold greater than 15 mA reliably indicates adequate screw position. A stimulation threshold between 10 and 15 mA was generally associated with adequate screw position, although exploration of the pedicle is recommended. A stimulation threshold less than 10 mA was associated with a significant cortical perforation in most instances

Platelet Gel (agf) Fails to Increase Fusion Rates in Instrumented Posterolateral Fusions

Study Design. Retrospective cohort study. Objective. To determine the effect on fusion of adding platelet gel to autologous iliac crest graft. Summary of Background Data. Platelet gel is an osteoinductive material prepared by ultra-concentration of platelets and contains multiple growth factors. Proprietary commercial methods are available for harvesting autologous platelet gel concentrates for use as graft supplement in spine fusions. Methods. We reviewed 76 consecutive patients who underwent instrumented posterolateral lumbar fusion with autologous iliac crest bone graft mixed with autologous growth factor (AGF). A control group was randomly selected from patients who underwent instrumented posterolateral lumbar fusion with autologous bone graft alone. The groups were matched for age, sex, smoking history, and number of levels fused. Demographic, surgical, and clinical data were collected from medical records. Diagnosis of nonunion was based on exploration during revision surgery or evidence of nonunion on computerized tomography. The Fisher exact test was used to compare fusion rates. Results. In both groups, mean age was 50 years, and 24% were smokers. The nonunion rate was 25% in the AGF group and 17% in the control group. This difference was not statistically significant (P = 0.18). Conclusions. Platelet gel preparation requires blood draws from the patient. This procedure adds to the risk and cost of surgery. The technique for AGF harvest evaluated in this study provides the highest concentration of platelets among the commercially available methods. Despite this, we showed that platelet gel failed to enhance fusion rate when added to autograft in patients undergoing instrumented posterolateral spinal fusion. The authors do not recommend the use of platelet gel to supplement autologous bone graft during instrumented posterolateral spinal fusion.

Initial Fusion Rates With Recombinant Human Bone Morphogenetic Protein-2/compression Resistant Matrix and a Hydroxyapatite and Tricalcium Phosphate/collagen Carrier in Posterolateral Spinal Fusion

Study Design. Prospective, randomized, unblinded study of iliac crest bone graft (ICBG) versus recombinant human bone morphogenetic protein-2/compression resistant matrix (rhBMP-2/CRM)in a posterolateral instrumented fusion procedure. Objectives. Document initial radiographic characteristics, based on computed tomography, with rhBMP-2/CRM for posterolateral fusion at 6 and 12-month intervals. Summary of Background Data. As the acceptance of INFUSE bone graft as an ICBG replacement becomes more widespread, surgeons have begun to study applications for rhBMP-2 in posterior spinal fusion. Preclinical studies have examined variables including carrier composition, rhBMP-2 concentration, and rhBMP-2 dose. Pilot studies have been performed with encouraging initial results. Methods. Patients with single level lumbar degenerative disease were enrolled in a randomized study of ICBG versus rhBMP-2/CRM in a posterolateral instrumented fusion procedure. Computed tomography scans at 6 and 12 months were graded as demonstrating no fusion (grade 1), partial or limited unilateral fusion (grade 2), partial or limited bilateral fusion (grade 3), solid unilateral fusion (grade 4), or solid bilateral fusion (grade 5). Results. At our institution, 74 patients (38 rhBMP-2/CRM, 36 ICBG) reached minimum 1-year follow-up and were included in this analysis. Mean fusion grade (scale1–5) at 6 months after surgery was 4.35 in the rhBMP-2/CRM group versus 3.09 in the ICBG group (P < 0.0001). At 1 year after surgery mean fusion grade was 4.62 in the rhBMP-2/CRM group versus 3.77 in the ICBG group (P < 0.0023). Conclusions. These early results are encouraging and suggest a more rapid incorporation and development of the fusion mass with rhBMP-2/CRM than iliac crest autograft in a single level posterior instrumented fusion.

Non-Neurologic Complications Following Surgery for Adolescent Idiopathic Scoliosis

BACKGROUND The reported prevalence of non-neurologic complications following corrective surgery for adolescent idiopathic scoliosis ranges from 0% to 10%. However, most studies were retrospective evaluations of treatment techniques and did not focus solely on complications. The purpose of this study was to determine the prevalence of non-neurologic complications following surgery for adolescent idiopathic scoliosis and to identify preoperative and operative factors that can increase this risk. METHODS The demographic data, medical and surgical histories, and prevalence of non-neurologic complications were reviewed in a prospective cohort of 702 patients who had undergone corrective surgery for adolescent idiopathic scoliosis and were consecutively enrolled in a multicenter database. RESULTS There were 556 female and 146 male patients. The mean age at the time of surgery was 14.25 years (range, eight to eighteen years). Five hundred and twenty-three patients had only posterior spinal surgery, 105 had only anterior spinal surgery, and seventy-four had a combined anterior and posterior procedure. There was a total of 108 complications in eighty-one patients, for an overall prevalence of 15.4%. There were ten respiratory complications (1.42%), six cases of excessive bleeding (0.85%), five wound infections (0.71%), and five cases of wound hematoma, seroma, or dehiscence (0.71%). Five patients, two with an early infection and three with late failure of the implant, required a reoperation. Factors that did not correlate with an increased prevalence of complications were age, body mass index, presence of cardiac or respiratory disease, previous surgery, pulmonary function, surgical approach, number of levels fused, graft material, use of a diaphragmatic incision, Lenke curve type, or region of the major curve. Although the number of patients with renal disease was small, these patients were 7.90 times more likely to have a non-neurologic complication. Increased blood loss as well as prolonged operative and anesthesia times were associated with a higher prevalence of non-neurologic complications. CONCLUSIONS The prevalence of non-neurologic postoperative complications following surgery for correction of adolescent idiopathic scoliosis in this study was 15.4%. The few factors noted to significantly increase the rate of complications include a history of renal disease, increased operative blood loss, prolonged posterior surgery time, and prolonged anesthesia time.

RhBMP-2 Versus Iliac Crest Bone Graft for Lumbar Spine Fusion : A Randomized, Controlled Trial in Patients Over Sixty Years of Age

Study Design. Prospective randomized controlled trial of rhBMP-2/ACS (Infuse bone graft) versus iliac crest bone graft (ICBG) for lumbar spine fusion in patients over 60 years of age. Objective. To report on clinical, radiographic, and economic outcomes, at 2-year follow-up, in patients treated by posterolateral lumbar fusion with rhBMP-2/ACS versus ICBG. Summary of Background Data. RhBMP-2/ACS is widely used “off-label” for posterolateral spinal fusion. Despite encouraging initial reports, outstanding issues include the need for evidence regarding safety and efficacy in an older population; and an assessment of cost-effectiveness. Methods. Patients over 60 years old were randomized to rhBMP-2/ACS (n = 50) or ICBG (n = 52). Oswestry Disability Index, Short Form-36, and numerical rating scales for back and leg pain were determined preoperatively and at 6, 12, and 24 months postoperatively. Fusion was evaluated by fine-cut computed tomography scan 2 years postoperatively by 3 reviewers. All in-patient and subsequent out-patient event costs were recorded by a dedicated hospital coder. Results. Two-year postoperative improvement in Oswestry Disability Index averaged 15.8 in the rhBMP-2/ACS group and 13.0 in the ICBG group. Mean improvement in Short Form-36 physical component score was 6.6 in the rhBMP-2/ACS group and 7.5 in the ICBG group. There were 20 complications in the ICBG group and 8 complications in the rhBMP-2/ACS group (P = 0.014). Sixteen ICBG and 10 rhBMP-2/ACS patients required additional treatment for persistent back or leg symptoms. Two rhBMP-2/ACS patients had revision procedures, 1 for nonunion. Eight patients in the ICBG group had revision procedures, 5 for nonunion. Mean fusion grade on computed tomography scan was significantly (P = 0.030) better in the rhBMP-2/ACS (4.3) compared with the ICBG group (3.8). Mean cost of the initial admission was

Treatment recommendations for idiopathic scoliosis: an assessment of the Lenke classification.

36,530 in the rhBMP-2/ACS group and