Posterior Spinal Fusion Instrumentation Research Articles

ACDF and posterior spinal fusion revision for posterior nonunion with deformity, myelopathy, and osteoporosis in an 87-year-old: A case report and literature review.

IntroductionCervical spondylotic myelopathy (CSM) is a spinal degenerative disorder that can ultimately lead to compression of the vertebral column with neurological sequelae. Although CSM is the most common spine pathology in the elderly American population, it remains a challenging disorder to treat among older patients.Case presentationWe report an 86 year old female patient with CSM with a history of posterior cervical fusion attempt on C3-C6 that progressed to C3-C6 nonunion with loose instrumentation. The patient had severe osteoporosis. With these indications, the patient underwent a combined anterior-posterior decompression and fusion (CAPDF) consisting of anterior cervical discectomy and fusion (ACDF) of the C3-C5, corpectomy of C6 and C7 with off FDA label use of polymethyl methacrylate augmentation (PMMA) fixation of T1 screws anteriorly for C3-T1 plate fixation and second stage instrumented posterior spinal fusion (PSF) of C3-T3. The patient had a successful fusion and reduction of her cervical spine pain with preservation of her neurological status.DiscussionWe report this case of multi-stage combined anterior and posterior fusion as a corrective measure for pseudarthrosis of a prior posterior cervical spinal fusion attempt.ConclusionIn the event of posterior spinal fusion instrumentation failure in patients with severe osteoporosis, combined multi-stage anterior-posterior fusion is a viable corrective intervention in octogenarians. This case also illustrated the utility of using PMMA for anterior cervical plate and screw stabilization in osteoporotic bone. The authors are not aware of the prior use of PMMA for screw fixation augmentation in the anterior cervical spine.

Quantifying the effect of posterior spinal instrumentation on the MRI signal of adjacent intervertebral discs.

Ex vivo porcine imaging study. Quantitatively evaluate change in MRI signal at the discs caudal to spinal fusion instrumentation. Individuals who receive posterior spinal instrumentation are at risk of developing accelerated disc degeneration at adjacent levels. Degeneration is associated with a loss of biochemical composition and mechanical integrity of the disc, which can be noninvasively assessed through quantitative T2* (qT2*) MRI techniques. However, qT2* is sensitive to magnetic susceptibility introduced by metal. Nine ex vivo porcine lumbar specimens were imaged with 3T MRI. Fast spin-echo T2-weighted (T2w) images and gradient-echo qT2* maps were acquired, both without and with posterior spinal fusion instrumentation. Average T2* relaxation times of the nuclei pulposi (NP) were measured at the adjacent and sub-adjacent discs and measurements were compared using t tests before and after instrumentation. The size of the signal void and metal artifact were determined (modified ASTM F2119-07) within the vertebral body and spinal cord for both MRI sequences. The relationship between T2* signal loss and distance from the instrumentation was evaluated using Pearson's correlation. There was no significant difference between adjacent and sub-adjacent NP T2* relaxation time prior to instrumentation (p = 0.86). Following instrumentation, there was a significant decrease in the T2* relaxation time at the adjacent NP (average = 20%, p = 0.02), and no significant difference at the sub-adjacent NP (average = - 3%, p = 0.30). Furthermore, there was a significant negative correlation between signal loss and distance to disc (r = - 0.61, p < 0.01). Spinal fusion instrumentation interferes with T2* relaxation time measurements at the adjacent disc but not at the sub-adjacent discs. However, there is sufficient signal at the adjacent disc to quantify changes in the T2* relaxation time following spinal fusion. Hence, baseline MRI scan following spinal fusion surgery are required to interpret and track changes in disc health at the caudal discs. N/A.

Wound healing without drains in posterior spinal fusion in idiopathic scoliosis.

To determine the frequency of wound infection and neurological injuries in patients with idiopathic scoliosis who underwent posterior spinal fusion without use of drains. Case series. Department of Orthopaedics, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia, from February 2007 to June 2010. Patients who underwent similar technique of posterior spinal fusion instrumentation for the correction of scoliosis without use of drain were included. Wound Demographics, wound healing, complications and duration of hospital stay were considered and described as frequency and mean values. The average age at the time of surgery was 12.80 ± 1.30 years, duration of surgery was 3.80 ± 0.86 hours, hospital stay was 3.84 ± 0.78 days and patients were followed-up over the last 30 months. There was no incidence of any neurological complication and deep infection. However, only 2 (4.16%) cases with superficial skin infection were treated with dressing and antibiotics with full recovery. The wound healing is adequate without using drain for patients with idiopathic scoliosis who underwent posterior spinal fusion and instrumentation when good wash, watertight closure technique and appropriate antibiotics coverage is provided.

Complications alter lumbar posterior spinal fusion instrumentation: influence of patient characteristics, surgical procedure and learning curve

Complications alter lumbar posterior spinal fusion instrumentation: influence of patient characteristics, surgical procedure and learning curve

Reliability of Retrospective Clinical Data to Evaluate the Effectiveness of Lumbar Fusion in Chronic Low Back Pain

Patients in whom a posterior spinal fusion instrumentation had been performed to treat low back pain were asked to recall their preoperative clinical status by retrospectively filling out the same 3 self-evaluation scales they had completed before surgery in a prospective fashion. To evaluate the impact of recollection error and compare outcomes using retrospective versus prospective methodologies among a cohort of patients treated with posterior spinal fusion instrumentation. Literature on spine surgery from 1990 to 2000 shows a greater increase in retrospective studies as compared to randomized controlled trials and other prospective studies. Cross-sectional studies evaluate therapeutic effectiveness by comparing the current condition with the recalled (retrospectively recorded) pretreatment condition. There are no studies analyzing the characteristics of recalled data in a cohort of patients with chronic low back pain treated with posterior spinal fusion instrumentation. The preoperative clinical status of 58 patients, 33 women and 25 men, with a mean age of 48.3 years (22-84 years) was assessed prospectively with 3 self evaluation questionnaires and retrospectively at a mean of 37.5 months (2-58 months) after surgery using the same questionnaires. The Wilcoxon test was used to compare prospective and retrospective preoperative data and to compare prospective outcomes with outcomes determined from cross-sectional data. Agreement between prospective and retrospective measures was estimated with intraclass correlation coefficients for absolute agreement and consistency. Comparisons between prospective and recalled data showed significant differences, demonstrating a worse preoperative situation when using retrospective data. Assessment of treatment effectiveness showed that cross-sectional evaluation significantly improved the real surgical outcome. Both absolute agreement and consistency intraclass correlation coefficients showed poor agreement between prospective and cross-sectional data, revealing no systematic bias. Follow-up, age, and gender did not modify agreement and cross-sectional overestimation. Relying on a patient's recall of preoperative clinical status is not an accurate method to evaluate surgical outcome after posterior spinal fusion instrumentation. Cross-sectional studies may overestimate the effectiveness of surgery.