Clinical and Radiographic Outcomes After Posterior Vertebral Column Resection for Severe Spinal Deformity with Five-Year Follow-up

BACKGROUND

Short-term studies have shown improved outcomes and alignment after posterior vertebral column resection for severe spinal deformity. Our goal was to report long-term changes in radiographic and health-related quality-of-life measures in a consecutive series of pediatric and adult patients undergoing posterior vertebral column resection with a minimum follow-up of 5 years.

METHODS

We reviewed all patients undergoing posterior vertebral column resection by a single surgeon prior to January 1, 2010, at a single institution. Standard preoperative and perioperative data were collected, including the Scoliosis Research Society (SRS)-22/24 instrument. Radiographic and health-related quality-of-life measures changes were evaluated at a minimum follow-up of 5 years.

RESULTS

One hundred and nine patients underwent posterior vertebral column resection prior to January 2010, and 54 patients (49.5%) were available for analysis: 31 (57.4%) were pediatric patients, and 23 (42.6%) were adult patients. The mean age (and standard deviation) was 12.5 ± 3 years for the pediatric cohort and 39.3 ± 20 years for the adult cohort. Improvements in the mean major Cobb angle at a minimum follow-up of 5 years were seen: 61.6% correction for the pediatric cohort and 53.9% correction for the adult cohort. The rates of proximal junctional kyphosis, defined as proximal junctional kyphosis of >10°, were 16.1% for the pediatric cohort and 34.8% for the adult cohort, but none underwent a revision surgical procedure for symptomatic proximal junctional kyphosis. Of the 54 patients, 30 (55.6%) sustained complications, 5 (9.3%) experienced postoperative neurological deficits, and 7 (13.0%) required a revision by 5 years postoperatively. Significant improvements were observed in the SRS-Self Image with regard to the pediatric cohort at 0.9 (p = 0.017) and the adult cohort at 1.3 (p = 0.002) and in the SRS-Satisfaction with regard to the pediatric cohort at 1.8 (p = 0.008) and the adult cohort at 1.3 (p = 0.005).

CONCLUSIONS

Posterior vertebral column resection offers substantial, sustained improvements in global radiographic alignment and patient outcome scores at 5 years. The major radiographic deformity was reduced by 61.6% in the pediatric cohort and by 53.9% in the adult cohort. Despite the high rate of complications, patients experienced significant improvement in the SRS-Self Image and SRS-Satisfaction domains.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Use of Bivector Traction for Stabilization of the Head and Maintenance of Optimal Cervical Alignment in Posterior Cervical Fusions

STUDY DESIGN

Retrospective analysis of consecutive case series.

OBJECTIVE

To introduce a novel method of stabilizing the cranium using bivector traction in posterior cervical fusions.

METHODS

A retrospective review of 50 consecutive patients undergoing instrumented posterior cervical arthrodesis was performed. All patients had at least 3 levels of subaxial fusion using the bivector traction apparatus. Patients' demographic data was recorded for the following: pre- and postoperative cervical lordosis, pre- and postoperative cervical sagittal vertical alignment (cSVA), and intraoperative complications from pin placements.

RESULTS

A total of 50 patients were studied. There were 31 females and 19 males. The mean age at the time of surgery was 49 years (range 35-79). A mean 5.8 levels were fused. The most common levels fused were C2-T3 in 14 patients followed by C2-T2 in 7 patients. In no case did the surgeon or assistant have to scrub out to adjust the alignment. The mean pre- and postoperative cervical lordosis was -6.0° and -10°, respectively (P = .04). The mean pre-and postoperative cSVA was 30.5 mm and 32 mm, respectively (P = .6). There were no complications related to placement of the Gardner-Well tongs.

CONCLUSION

The bivector traction is an easy, safe, and effective method of stabilizing the head and obtaining adequate cervical sagittal alignment.

CT accuracy of percutaneous versus open pedicle screw techniques: a series of 1609 screws

INTRODUCTION

Traditional open exposure for posterior instrumentation requires significant soft tissue mobilization and causes significant blood loss and increased recovery time. Mal-placed screws can injure nerve roots, the spinal cord, viscera, vasculature and the cardiopulmonary system. Placement of pedicle screws using a minimally invasive technique can decrease bleeding risk, damage to soft tissues, and post-operative pain. The purpose of this study is to compare the radiographic accuracy of open free-hand versus percutaneous technique for pedicle screw placement.

METHODS

Consecutive patients undergoing thoracolumbar surgery from September 2006 to October 2011 with post-operative CT imaging were included in this study. Three-dimensional screw positioning within the pedicle and the vertebral body was assessed on CT. The magnitude and location of violations were measured and recorded. Facet breaches at the cephalad and caudad ends of the construct were documented and graded.

RESULTS

Two-hundred and twenty-three patients met the inclusion criteria for a total of 1609 pedicle screws. Seven-hundred and twenty-four screws were placed using a standard open free-hand technique and 885 were placed percutaneously. There was a significant difference in overall pedicle breach rates: 7.5 % for open and 4.7 % for percutaneous techniques. The magnitude of breach was greater for the percutaneous technique compared to the open technique: 5.4 versus 3.7 mm, respectively. The difference in vertebral body breaches was also significant: 11.3 % for open and 3.6 % for percutaneous. The rates of facet breach did not significantly differ.

DISCUSSION AND CONCLUSION

This is the largest series comparing the accuracy of percutaneous to open pedicle screw placement. The rates of pedicle, vertebral body, and facets breaches in the percutaneous group were similar to the rates in the open technique group as well as rates reported in the literature. This demonstrates that the percutaneous technique described here is an accurate alternative to standard open free-hand technique.

Extreme lateral interbody fusion for the treatment of adult degenerative scoliosis

Extreme lateral interbody fusion (XLIF; NuVasive Inc., San Diego, CA, USA) is a minimally invasive lateral transpsoas approach to the thoracolumbar spine. Though the procedure is rapidly increasing in popularity, limited data is available regarding its use in deformity surgery. We aimed to evaluate radiographic correction using XLIF in adults with degenerative lumbar scoliosis. Thirty consecutive patients were followed for an average of 14.3 months. Interbody fusion was completed using the XLIF technique with supplemental posterior instrumentation. Plain radiographs were obtained on all patients preoperatively, postoperatively, and at most recent follow-up. Plain radiographic measurements of coronal Cobb angle, apical vertebral translation, segmental lordosis, global lordosis, disc height, neuroforaminal height and neuroforaminal width were made at each time point. CT scans were obtained for all patients 1 year after surgery to evaluate for fusion. There was significant improvement in multiple radiographic parameters from preoperative to postoperative. Cobb angle corrected 72.3%, apical vertebral translation corrected 59.7%, neuroforaminal height increased 80.3%, neuroforaminal width increased 7.4%, and disc height increased 116.7%. Segmental lordosis at L4-L5 increased 14.1% and global lordosis increased 11.5%. There was no significant loss of correction from postoperative to most recent follow-up. There was an 11.8% pseudoarthrosis rate at levels treated with XLIF. Complications included lateral incisional hernia (n=1), rupture of anterior longitudinal ligament (n=2), wound breakdown (n=2), cardiac instability (n=1), pedicle fracture (n=1), and nonunion requiring revision (n=1). XLIF significantly improves coronal plane deformity in patients with adult degenerative scoliosis. XLIF has the ability to correct sagittal plane deformity, although it is most effective at lower lumbar levels.

Clinical outcomes of extreme lateral interbody fusion in the treatment of adult degenerative scoliosis

Introduction. The use of extreme lateral interbody fusion (XLIF) and other lateral access surgery is rapidly increasing in popularity. However, limited data is available regarding its use in scoliosis surgery. The objective of this study was to evaluate the clinical outcomes of adults with degenerative lumbar scoliosis treated with XLIF. Methods. Thirty consecutive patients with adult degenerative scoliosis treated by a single surgeon at a major academic institution were followed for an average of 14.3 months. Interbody fusion was completed using the XLIF technique with supplemental posterior instrumentation. Validated clinical outcome scores were obtained on patients preoperatively and at most recent follow-up. Complications were recorded. Results. The study group demonstrated improvement in multiple clinical outcome scores. Oswestry Disability Index scores improved from 24.8 to 19.0 (P < 0.001). Short Form-12 scores improved, although the change was not significant. Visual analog scores for back pain decreased from 6.8 to 4.6 (P < 0.001) while scores for leg pain decreased from 5.4 to 2.8 (P < 0.001). A total of six minor complications (20%) were recorded, and two patients (6.7%) required additional surgery. Conclusions. Based on the significant improvement in validated clinical outcome scores, XLIF is effective in the treatment of adult degenerative scoliosis.

Seroprevalence of Helicobacter pylori in the adult population of Christchurch: risk factors and relationship to dyspeptic symptoms and iron studies

AIM

To determine the prevalence of Helicobacter pylori infection in subjects randomly selected from the Christchurch population and to determine the risk factors and symptoms related to the infection.

METHODS

A list of names was randomly generated from the 1996 electoral roll and subjects were sequentially contacted and invited to participate. A questionnaire on dyspeptic symptoms was completed and the subject's serum was analysed for H. pylori antibodies using the Roche method. Equivocal samples were retested by the Meridian method.

RESULTS

One thousand and sixty-four subjects participated in the study. In four subjects results for H. pylori were indeterminate and these subjects were excluded from analysis. Of the remaining 1060 subjects, 254 (24.0%) were seropositive for H. pylori. The seropositivity in males (n=444) was 25.9% and in females (n=616) 22.6%. On multivariate analysis age, ethnicity, low income and smoking > 20 cigarettes per day were all independent predictors of H. pylori seropositivity. H. pylori positive subjects had shorter stature compared to those who were seronegative. The symptom scores for dyspepsia were similar in both the seropositive and seronegative subjects. In males the serum iron levels were lower in seropositive subjects but there were no significant differences in serum ferritin in either males or females between seropositive and seronegative subjects.

CONCLUSION

H. pylori is a common infection in the Christchurch community with the prevalence increasing significantly with age. H. pylori positive subjects had shorter stature and in males lower serum iron levels were observed. Infection was not associated with an increased risk of dyspeptic symptoms.

The significance of haemochromatosis gene mutations in the general population: implications for screening

BACKGROUND

Haemochromatosis is associated with mutations in the HFE gene but the significance of these mutations in the general population is unknown.

AIMS

To determine the frequency of HFE gene mutations in the general population, their effect on serum iron indexes, and their role in screening for haemochromatosis.

METHODS

Deoxyribonucleic acid (DNA) from 1064 randomly selected subjects was analysed for the C282Y and H63D mutations in the HFE gene. Serum iron, transferrin saturation, and ferritin were measured and individuals with increased iron indexes were investigated to confirm or exclude a clinical diagnosis of haemochromatosis.

RESULTS

Mutations were identified in 409 individuals (38.4%) with heterozygote (carrier) frequencies of 13.2% and 24.3% for the C282Y and H63D mutations respectively. Heterozygosity for either mutation significantly increased serum iron and transferrin saturation but despite a similar trend for ferritin, this was only significant for C282Y homozygotes. Five individuals (0.47%) were homozygous for the C282Y mutation, three of whom had haemochromatosis confirmed by liver biopsy (0.28%). The other two C282Y homozygotes would not have been detected by phenotypic screening alone.

CONCLUSIONS

HFE mutations are present in 38.4% of the population, affect serum iron indexes, and are important determinants of iron status. The population frequency of genetically defined haemochromatosis (C282Y homozygosity) is approximately one in 200 and is higher than the prevalence of clinically apparent haemochromatosis.

Gallbladder volume: comparison of diabetics and controls

Diabetics are known to have an increased prevalence of gallstones. The aim of this study was to investigate whether diabetics have increased gallbladder volumes that would predispose to stasis, nucleation of cholesterol crystals, and gallstone formation. The gallbladder volume of 271 diabetic subjects and 277 controls was determined by ultrasound using the ellipse formula. Gallbladder volume was also determined by the sum of the cylinders method in 143 cases with a strong correlation (r = 0.89) between the two methods. Using analysis of variance, gallbladder volume was influenced by both diabetic type (NIDDM = 33.68 cm3, IDDM = 26.84 cm3, controls = 29.05 cm3; P = 0.018) and the presence of gallstones (gallstones = 32.04 cm3, no gallstones = 27.58 cm3; P = 0.018). The variation in gallbladder volume between NIDDM, IDDM, and control subjects was influenced by the presence of gallstones (P = 0.024, interaction term from ANOVA). Significant differences (P < 0.001) were only found between NIDDM vs IDDM and NIDDM vs control in the nongallstone group (NIDDM = 34.33 cm3, IDDM = 25.08 cm3, control = 25.17 cm3). Males had significantly larger gallbladder volumes than females: 31.98 cm3 vs 27.74 cm3 (P = 0.023). After the inclusion of BMI, HDL cholesterol, triglyceride, and age in a statistical model with gender and diabetic type in those without gallstones, significant differences were still found between NIDDM and IDDM (P = 0.013) and NIDDM and controls (P = 0.005), demonstrating that NIDDM is an independent predictor for increased gallbladder volume.

Postoperative pain control after lumbar spine fusion. Patient-controlled analgesia versus continuous epidural analgesia

STUDY DESIGN

A prospective, randomized, double-blind clinical trial.

OBJECTIVE

To compare the efficacy of postoperative continuous epidural analgesia versus patient-controlled analgesia in patients undergoing lumbar fusion.

SUMMARY OF BACKGROUND DATA

Controversy remains regarding the optimal strategy for postoperative pain control.

METHODS

Fifty-four patients were divided into two treatment groups. There was no difference between the groups with respect to age, levels fused, estimated blood loss, and use of spinal instrumentation. Patient-controlled analgesia or epidural analgesia was administered in a double-blind manner for a 3-day postoperative course. Each patient received both an epidural and a patient-controlled analgesia delivery system; 26 received the epidural active agent and 28 received patient-controlled analgesia. Postoperative time to liquids and solid food, ambulation, length of stay, and side effects was recorded. Pain was evaluated by a visual analog scale on postoperative days 1, 2, and 3.

RESULTS

Results showed no difference between the groups with reference to diet, ambulation, length of stay, and visual analog scale scores. Minor side effects occurred in 71% of patients in both groups. No major complications occurred. Epidural catheter dislodgment occurred in 11% of patients. The total cost for epidural analgesia was approximately $550 more than that for patient-controlled analgesia for a 3-day postoperative course.

CONCLUSIONS

These data suggest that there is no clinical advantage of epidural opiate/local anesthetic analgesia over systemic opiate by patient-controlled analgesia for spinal fusion patients. However, possible technical limitations (namely, the low dosage of bupivacaine and placement of the catheter tip) may have prevented adequate delivery of anesthetic to the involved segments. Although the incidence of side effects is similar, cost factors and a high incidence of epidural catheter dislodgment favor use of patient-controlled analgesia.

Lumbar epidural varix as a cause of radiculopathy

STUDY DESIGN

Venous outflow obstruction or congestion has been implicated in the etiology of some lumbar radicular syndromes. Ten cases of epidural varices or variants manifesting themselves as masses within the lumbar spinal canal or adjacent foramina have been seen.

OBJECTIVES

Diagnosis was made by multiplanar cross-sectional magnetic resonance and computed tomography imaging and confirmed in five patients by operative findings. These venous abnormalities differ from cases of arteriovenous malformations described in the literature.

METHOD

Surgical treatment consisting of coagulative oblation and/or excision of the lesion was consistently successful in the five patients who underwent operations for recalcitrant symptoms. The other five patients experienced spontaneous resolution of symptoms. Three distinctly different types of these abnormalities have been identified.

RESULTS

The described entity may account for some previously unexplained or spontaneously resolving cases of lumbar radiculitis.

CONCLUSIONS

Knowledge of the existence of this condition, its possible etiologies, and its imaging characteristics may assist in its recognition and improved management of patients with it.

Lumbar intervertebral disc transfer. A canine study

STUDY DESIGN

Degenerative lumbar disc disease has been implicated as a cause of low back pain. Current treatment options for low back pain involve nonphysiologic fusion of the involved segments and have variable success rates. This is an experimental study of lumbar intervertebral disc transplantation using a canine surgical model.

OBJECTIVES

This study evaluated the feasibility of lumbar disc transplantation and its effects on disc metabolism and morphology.

METHOD

Eight mature mongrel dogs underwent disc transfer surgeries, in which the L2-L3 and L4-L5 intervertebral discs, with a small segment of adjacent superior and inferior vertebral body, were removed and transposed. The transplanted disc were stabilized by plates or by a flexible cable wire construct using Songer cables (DANEK, Inc., Memphis, TN). Unrestricted activity was allowed postoperatively. At 4 months, the spines were harvested, and the transplanted discs were evaluated biochemically and histologically. Intervening nontransplanted discs served as viable controls and thrice-frozen discs served as nonviable controls. Cell viability was assessed by measuring proteoglycan synthesis and DNA content.

RESULTS

Proteoglycan synthesis (35S uptake normalized to DNA content) was maintained in transplanted anulus fibrosus tissue, but was decreased in nucleus pulposus samples (P < 0.05). DNA content was not altered significantly in the transplanted discs. Histologic analysis of the transplanted discs showed revascularization and remodeling of the bone adjacent to the disc and preservation of the lamellar architecture of the anulus fibrosus. The transplanted nucleus pulposus samples had chondrocyte-like cells present, but the staining characteristics of the nucleus material was variable. The contour of the transplanted disc endplates was irregular in all specimens.

CONCLUSIONS

The structure and function of autograft intervertebral discs were maintained after disc transfer surgery; the transplant discs, however, were not completely normal in either their morphology or their metabolic functioning.

Anterior lumbar interbody fusion for discogram concordant pain

Twenty-two patients undergoing anterior lumbar interbody fusion (ALIF) for discogram concordant low-back pain were retrospectively evaluated by objective criteria. Results were poor in all two-level fusions. Among single-level fusions, there were 35% good, 18% fair, and 47% poor results. Patients with previous surgery or workmen's compensation did poorly as a group despite positive discography. Subjective results were difficult to assess.

Klebsiella pneumoniae arthritis of the hip in a diabetic patient

Chronic debilitating diseases may predispose to various joint infections, but early diagnosis of septic arthritis of the hip may be difficult. Klebsiella pneumoniae is an organism uncommonly found in joint infections. We have reviewed the literature on Klebsiella pneumoniae septic arthritis and described a case of a diabetic patient who had severe destruction of the hip joint over a six-month interval due to Klebsiella pneumoniae infection.