Session 7: Spine

Torsdag den 24. oktober
13:30 – 15:00
lokale: Stockholm/Copenhagen
Chairmen: Thomas Andersen / Martin Gehrchen

61. Dural tears influence on length of admission and outcome in spinal surgery
Randi Holm, Dorte Clemmensen, Mikkel Andersen
Sector for Spine Surgery and Research, Region of Southern Denmark, Vejle Sygehus; Sector for Spine Surgery and Research, Region of southern Denmark, Vejle Sygehus

Background: Decompression of lumbar spinal canal is one of the most frequent operations on the spine. The most common complication seems to be a peroperative dural lesion.
Purpose / Aim of Study: The aim of this study is to determine the frequency of iatrogenic dural tear, influence on the length of hospital admission and outcome one year postoperative.
Materials and Methods: The Danish Spine Register “DaneSpine” documents the majority (99.6 %) of lumbar spine operations at the Sector for Spine Surgery and Research, Region of Southern Denmark. Within the framework of this register, consecutive operations involving decompression of the lumbar spinal canal were studied regarding the incidence of Iatrogenic dural lesion, length of hospital admission and one year postoperative outcome.
Findings / Results: A total of 1419 patients had lumbar neural decompressive surgery - 738 patients were treated for spinal stenosis and 681 for herniated disc. The overall incidence of dural tear was 7.7 % (109 dural tear). Patients with spinal stenosis accounted for 81 of the lesions (incidence 11%) and the remaining 28 lesions (incidence 3 %) occurred while operating patients with herniated disc. The risk of dural tear after secondary surgery was 11.9% versus 6.2% for primary. The length of hospital admission increased from 2.9 to 4.5 days (p = 0.00) among patients with a dural tear. In the patient-based outcome parameters there were no significant differences in outcome between patients with and without a dural lesion.
Conclusions: The incidence of iatrogenic dural tears was 7.7 %. The incidence of dural tear was almost doubled in secondary surgery. Patients with dural tear were hospitalized 1.6 days longer. However, this did not affect the one year outcome negatively.

62. Intervertebral disc degeneration followed by interference of endplate nutritional pathway in adolescent porcine models
Ran Kang, Haisheng Li, Steffen Ringgaard, Kresten Rickers, Lin Xie, Cody Eric B¨¹nger
Orthopedic Research Lab, Aarhus University Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; MRI center, Skejby Hospital; Orthopedic Research Lab., University Hospital of Aarhus; Department of Orthopedic surgery, Jiangsu Province Hospital on Integration of Chinese and Western Medicine

Background: Insufficient nutritional supply has been proposed as the final common pathway of intervertebral disc degeneration (IDD). Inconsistently, Polymethylmethacrylate (PMMA) bone cement blocking the pathway did not result in IDD in mature animal models. As nowadays there is a tendency to apply vertebroplasty treatments in younger patients, thus we investigated this PMMA blocking affect in adolescent animal models.
Purpose / Aim of Study: To examine the intervertebral disc changes after interference of endplate nutritional pathway.
Materials and Methods: In each of 8 adolescent pigs, two lumbar intervertebral discs were either blocked by cement in both endplate pathway, or stabbed by scalpel in annulus fibrosus, with intact disc as normal control. Magnetic resonance imaging (MRI) including T1, T2- weighted, T2-weighted 3D, sagittal T2 mapping, was performed pre and 3 months post intervention. Postcontrast series T1-weighted MRI also performed at the end.
Findings / Results: The cement blocking area was 38.92¡À10.05 % (from 27.09% to 50.56%) of vertebral bodies on both sides of disc. After 3 months, these cement blocked discs showed severe IDD, with the percentage of disc height index (%DHI) and Nucleus Pulposus area (%NP-area) significantly lower than the normal controls. And the NP T2 value was 188.43¡À75.66 ms also significantly lower than the normal control 356.71¡À38.99 ms (P=0.0089). Similar results were found in positive controls of annulus injury discs. Further post-contrast MRI showed damaged nutrient transport pathway in the cement blocked discs.
Conclusions: Severely interfering endplate nutritional pathway in adolescent porcine models caused IDD. More concern about adjacent IDD needs to be taken when PMMA bone cement is used in vertebroplasty or balloon kyphoplasty treatments, especially in younger patients.

63. Short-Term Mortality and Morbidity after Surgical Treatment of Fixed Spinal Deformities. Two-Years Experience in 102 Adult Patients
Tanvir Bari, Martin Gehrchen, Sven Karstensen, Sidsel Fruergaard, Benny Dahl
Rygsektionen, Rigshospitalet

Background: Increasing evidence suggests that improved sagittal balance is of major importance to obtain improved health related quality of life in the surgical treatment of adult spinal deformities. The two primary surgical techniques used are pedicle subtraction osteotomy (PSO) and vertebral columna resection (VCR).
Purpose / Aim of Study: To assess short-term complications after surgical treatment of fixed spinal deformities.
Materials and Methods: In a prospective cohort study, all complications in adult patients undergoing posterior correction of fixed spinal deformities in the thoracolumbar region from February 1st 2010 through January 31st 2012 were included. Patients were excluded if they had undergone previous posterior instrumentation on more than five levels for a degenerative condition. Also, patients with previous malignant, infectious or traumatic conditions of the spine were excluded . Survival status and the neurologic condition was assessed at the one-year follow-up.
Findings / Results: A total of 102 patients were operated with a mean age of 61 at the time of surgery (range 19 - 86). 52 were men and 50 women. A median number of 10 levels were instrumented with pedicle screws (range 5 - 17). 81 % of the patients underwent PSO and 19% VCR. The 30-day mortality was 1.2% and the primary complication was dura lesion (16%). Two patients (2 %) had permanent neurological deficit corresponding to 1 ASIA motor grade deterioration and four patients (4 %) patients had persisting sensory deficits.
Conclusions: This prospective one-center study confirms recent national database reports suggesting that surgical treatment of fixed spinal deformities carries a relatively low risk of short-term mortality and severe neurological complications.

64. TLIF surgery results in slightly higher risk of neurogenic leg pain 2 years after surgery compared to standard instrumented posterolateral fusion. Results from a randomized clinical trial.
Kristian Høy, Blazej Grycel, Thomas Andersen, Peter Helmig, Ebbe Stender Hansen, Cody Bünger
Orthopedic, Spine Section, Århus University Hospital; Orthopedich, Spine Section, Århus University Hospital

Background: TLIF has gained increasing popularity obtaining circumferential fusion using a posterior procedure only
Purpose / Aim of Study: Due to cage insertion close to the exiting nerve root concerns has been raised whether the procedure carries an increased risk of subsequent neurogenic pain due to damage of the dorsal nerve root ganglion.
Materials and Methods: Pain drawings from 100 pat. (40 male, 58 female) included in a RCT comparing TLIF to posterolateral instrumented fusion (PLF) was analyzed. 51 had TLIF, 47 PLF. Mean age 49(TLIF)/45(PLF). Pain drawings were completed preoperatively,1y, 2y follow-up. The pain drawing consisted of a front and back outline of a person as well as the area under the feet. Six different symbols could be used for marking pain: dull/aching, burning, numbness, pins and needles, stabbing/cutting and muscular cramps. Pain drawing analysis were done assessing presence and type of pain marks in both legs.
Findings / Results: A slightly higher number of pats. in the TLIF group reported any leg pain at 2y: No leg pain 47% (PLF) 37% (TLIF), Unilateral leg pain 31% (PLF) 25% (TLIF), Bilateral leg pain 22% (PLF) 37% (TLIF), p=0.270. Likewise looking at pain radiating below the knee: No leg pain 55% (PLF) 45% (TLIF), Unilateral leg pain 29% (PLF) 25% (TLIF), Bilateral leg pain 16% (PLF) 29% (TLIF), p=0.294. Numbness and pins & needles on the anterior aspect of the lower leg were marked by 10% and 12% of TLIF patients compared to 6% and 4% in PLF pats. (p=0.498/0.197). Looking at the posterior aspect of the lower leg numbness and pins & needles were marked by 10% and 10% of TLIF pat. compared to 16% and 8% in PLF (p=0.332/0.774).
Conclusions: TLIF pats. were more likely to have bilateral leg pain 2y after surgery and a used pain symbols more commonly associated with neurogenic pain to a slightly higher extent than patients with PLF

65. A Comparison of the Tokuhashi Revised and the Tomita Scoring Systems in a prospective Cohort of Patients with Metastatic Epidural Spinal Cord Compression (MESCC)
Søren Schmidt Morgen
Spine Section, Department of Orthopedic Surgery, Copenhagen University Hospital, Rigshospitalet

Background: Expected survival time in patients with acute symptoms of MESCC is a crucial element in the pre-operative evaluation. Consequently, expected survival is a variable in preoperative scoring systems such as the Tokuhashi Revised score (TRS) and the Tomita score (TS). Because of the improved survival among cancer patients it is relevant to reassess the validity of these two systems in a prospective, consecutive, and large cohort of patients with MESCC.
Purpose / Aim of Study: To validate and compare the TRS and the TS in patients with MESCC.
Materials and Methods: During 2011 we included 544 patients with acute symptoms of MESCC. All patients were scored with the TRS and with the TS and were divided into the corresponding prognostic groups. One-year survival status was obtained in all patients and compared to the estimated survival of each group as predicted by the scoring systems. Survival curves were estimated with the Kaplan Meyer methods and were evaluated with the Log Rank test.
Findings / Results: The mean age was 65 years (range 20- 95) and 57% of the patients were men. The most common primary tumors were lungs (23%), prostate (21%), and breast (18%). The positive predictive values regarding one-year survival were 47% for the TRS and 14% for the TS. The actual survival for each of the TRS prognostic groups was significantly different (P < 0.0001). The same applied to the TS groups but with some overlap of CI’s. In both the TRS and the TS groups the survival was shorter than estimated (P < 0.0001).
Conclusions: The TRS and TS accurately separated the patients into groups according to survival but the estimated survival was, contrary to what we expected, longer than in our cohort and a modification of the scoring systems may be necessary to improve prediction regarding survival. The TRS was more accurate than the TS in predicting one-year survival.

66. Implementing DaneSpine
Karen Højmark, Ane Simony, Carsten Ernst, Mikkel Andersen
Sector for Spine Surgery and Research, Region of Southern Denmark, Vejle Sygehus; Sector for Spine Surgery and Research, Region of southern Denmark, Vejle Sygehus

Background: During several years, the Danish helath system lacks proper documentation of spinal surgery outcome. The first attempt to establish a national database – DiscusBasen - supported by the Danish National Board of Health was closed down in 2005 due to a coverage rate of less than 20% . In 2009 The Danish Society of Spinal Surgery (DRKS) acquired DaneSpine (DS), with the ambition to establish a national Danish spine database. Sector for Spine Surgery and Research (SSSR), Region of Southern Denmark implemented DS in June 2010.
Purpose / Aim of Study: The aim of this study was to investigate the registration rate and follow-up of surgical procedures in DaneSpine, and estimate the cost of running DS at a centre of our size.
Materials and Methods: Surgical procedure codes registered in the patient administration system was compared to the number of operations recorded in DaneSpine in 2010. Time and costs required for collection and data entry were estimated.
Findings / Results: 486 spinal interventions at SSSR were performed in the second half of 2010. In DS 484 interventions (99.8%) were recorded. At follow-up after one and two years data were available from 406 and 372 patients, corresponding to 84/77 %. The annual cost of administering DS is approximately DDK. 380 000 with an expected output of 1,200 interventions - equivalent of DDK. 300 per patient.
Conclusions: With our setup DaneSpine is a reliable tool, to collect data and monitor our activity and surgical outcome.

67. Vertebroplasty for treating painful vertebral body fractures, in patients with multipel myeloma
Ane Simony, Mikkel Østerheden Andersen, Niels Abildgaard, Marius Gaurilcikas
Rygkirurgisk Afdeling, Middelfart Sygehus; Hæmatologisk Afdeling, Odense Universitets Hospital

Background: Multiple myeloma is a disease that causes osteolytic destruction of the bones and has a incidents of 6/100000, with causes 300 new patients a year. 40 % of the patients have painful vertebral body fractures, at the time they are diagnosed with the disease. Vertebroplasty (VBP) is an invasive procedure with cement augmentation of vertebral fractures. It was introduced in France, by radiologist, in the 90’s as a treatment for haemangiomas in the vertebral bodies. It is now used for treating osteoporotic fractures and fractures caused by cancer.
Purpose / Aim of Study: The aim of this study was to assess the safety and efficacy of VBP for vertebral body fractures in myeloma patients
Materials and Methods: This is a retrospective review of 18 patients with multiple myeloma, treated with PVP at the Spine Center at Odense University Hospital, from 2004- 2010. The median age of the patients was 62,5 years, 11 males and 7 females. The PVP procedure was performed at 71 levels, from TH6-S2. The procedure was performed in local anesthetic, and the patients could leave the hospital after 4 hours. All patients had a preop X-ray and MRI scan with STIR. The patients had a postop X-ray after 3 months and Visual Analog Scale was used, preop and after 3 months, as assessment for pain.
Findings / Results: The median VAS(back) was preop 7,6 and 3,2 post op after 3 months. (p <0,05). 5 patients didn’t participate in the 12 weeks follow up, 1 had died, 4 was admitted to hospital. The patients had a significant reduction of the back pain. We had leakage in 8 of the 71 treated levels (12,5%), none of them causing any neurological symptoms. There were no cases of infections, pulmonary embolisms or other complications.
Conclusions: PVP is an effective and safe procedure in the treatment of painful vertebral Fractures, in patients with multiple myeloma.

68. Long term outcome and health care utilizations following surgical treatment of adult spine deformity
Shallu Sharma, Thomas Andersen, Cody Eric Bunger, Rikke Soegaard
Deparment of Othropedics, Aarhus Univeristy Hospital , Noerrebrogade; Senior reasearcher at Region Midt, Aarhus Univeristy Hospital , Skejby

Background: The long term effects of scoliosis surgery in adults on health and heath care use is undetermined
Purpose / Aim of Study: To assess the long term impact of deformity surgery on the pain, employment, self reported benefits and health-care use and investigate if any process/patient variables influence the health improvement and degree of healthcare use
Materials and Methods: 123 patients having undergone deformity correction surgery between 1992- 2009 (mean age 42.45 years) were included. They filled Scoliosis life quality,-Dallas Pain and EQ-5D questionnaires at follow up. Data on primary and hospital based health care sectors use were obtained from The National Health Insurance Service Registry and The National Patient Registry. Follow-up ranged between 1.4-18.6 years
Findings / Results: A significant reduction in use of pain medication was seen (p=0.00). Long term employment status was maintained in level to pre-surgery without deterioration. Activity related endurance improved in 38% patients. Perceived emotional-cosmetic improvement ranged between 40-77%. EQ-5D score was significantly poorer (0.6 vs. 0.8) in operated patients compared to matched controls.Surgery had highest impact on health care use for the first 2 years after surgery. Spine related hospital use decreased in the followup. Primary-sector use increased in the follow-up due to increasing visits to the general practitioners (GP) and physical therapists (PT). Education level was significantly associated with the variability in EQ-5D and hospital utilization. Unemployed work status was associated with higher visitations to the GP and PT.
Conclusions: Deformity correction surgery in adults does not lead to an alarming rise in the long-term hospital use but primary care use increases. Patients experience maintenance of working status and improved activity with low complication rate.

69. Moderate to Almost Perfect Inter- and Intrarater Agreement in Assessment of Adult Spinal Deformity using the SRS-Schwab Classification
Dennis Hallager Nielsen
Spine Unit, Dept. of Orthopaedic Surgery, Rigshospitalet

Background: The lack of consensus regarding classification of adult spinal deformities constitutes a challenge in choosing the optimal treatment for each patient. Recently the Scoliosis Research Society- Schwab Adult Spinal Deformity Classification (SRS-Schwab) has been proposed. This system includes four coronal curve types and three sagittal modifiers that are correlated to health related quality of life: Pelvic incidence minus Lumbar lordosis (PI-LL), Pelvic tilt (PT) and Global alignment based on Sagittal vertical axis (SVA). Each modifier has three grades: 0, + and ++.
Purpose / Aim of Study: To analyze inter- and intrarater agreement in a large consecutive series of patients using unmarked radiographs classified by spine surgeons with different levels of experience.
Materials and Methods: SRS-Schwab classification of 67 consecutive adult patients referred for surgical evaluation of a spinal deformity was done blinded by two senior spine surgeons, one attending, and one spine fellow. After two weeks the classifications were repeated on re-coded radiographs. Crude agreement (%) and Fleiss’ Kappa coefficients (k) were calculated.
Findings / Results: Interrater agreement averaged 67% (k = 0.70) for curve type, 72% (k = 0.70) for PI-LL, 81% (k = 0.80) for PT, 90% (k = 0.90) for Global alignment and 39% (k = 0.55) for Entire grade. Intrarater agreement averaged 86% (k = 0.79) for curve type, 89% (k = 0.78) for PI-LL, 94% (k = 0.88) for PT, 96% (k = 0.93) for Global alignment and 70% (k = 0.67) for Entire grade. According to Landis and Koch the observed agreements were considered substantial to almost perfect for curve type and sagittal modifiers (PI-LL, PT, SVA) and moderate for Entire Grade.
Conclusions: Our results correspond to previous findings and support the use of the SRS-Schwab classification system in assessment of adult spinal deformities.

70. 3D correction by novel growth instrumentation in severe deformities of the immature spinal
Cody Eric Bünger, Barbara Jensen, Haisheng Li, Ebbe Stender Hansen , Haolin Sun, Kristian Hoy
Spine Section Dept of Orthopedics E, Aarhus University Hospital, Aarhus University Hospital; Orthopedic Research Lab, Aarhus University Hospital; Orthopaedic Dept E, , Aarhus University Hospital; Orthopaedic Dept E, Aarhus University Hospital ; Dept of Orthopedics E, Aarhus University Hospital

Background: In surgical management of severe spinal deformity in the Infant ideally spinal growth and 3D correction should be preserved. The current techniques do not fulfill these goals. We developed a new double rod growth system based on 3 platforms and multiple growth tubes applied by MIS as a stand alone or with osteotomy.
Purpose / Aim of Study: Aims of study were 1)to analyze 3D correction. and truncal height at index surgery 2) To measure spinal growth per year in relation to different underlying pathologies.. 3) To monitor adverse events.
Materials and Methods: In total 32 children aged mean 8 years (3 - 11), with mean 78 degrees (55 - 124) scoliosis , 50 degrees (10-105) kyphosis and up to 30 degrees rotation were operated using pedicle screws, hooks and double growth tubes mounted on a cranial, apical and caudal platform. Scoliosis correction is achieved by distraction,, rotation by apical compression and distraction, whereas the sagittal contour is created outside the growth tube areas. Underlying pathology were neuromuscular (8), congenital (7), syndromic 6,juvenile idiopathic 7 and miscellaneous 4. Lengthening procedures in GA were one day admissions undertaken every 5 -6 months.
Findings / Results: Mean index OR time was 175 min (100 - 240). the lengthenings 30 min (10 - 120). The index surgery resulted in a mean 60% frontal Cobb correction, and a 70% correction of kyphosis. In 3 cases osteotomies were integrated. Truncal lengthening was up to 22 cm over 3 years, instrumented growth after index surgery, mean 1.8cm/year. Complications were loss of screw/rod lock 3 pat, hygroma formation 3 pat. necessitating 6 reoperations and. asymptomátic metal debris.
Conclusions: Our hybrid double rod growth system has radically improved management of severe spinal deformities. Major improvements of the implants to minimize debris are needed..

71. Physical and mental outcome of 500 patients with spinal stenosis operated by decompression alone.
Rikke Rousing, Frederik Busch, Henrik Grønvall
Sector for Spine Surgery and Research, Region of Southern Denmark, Vejle Sygehus

Background: Spinal stenosis, an abnormal narrowing of the spinal canal, is very common among elderly people. Symptoms include pain, numbness, parasthesia and loss of motor control and are often worsened by walking and standing. The condition may be disabling for the patients and some will need decompression surgery, to relive the symptoms. In case of instability fusion may be considered. The outcome after decompression alone is not well described in the literature.
Purpose / Aim of Study: The purpose of this study is to describe quality of life and the physical and mental outcome of the first 500 patients with spinal stenosis operated at the Sector for Spine Surgery and Research, Region of Southern Denmark, by decompression alone.
Materials and Methods: All patients are operated at the Sector for Spine Surgery and Research, Region of Southern Denmark. The data is collected in DaneSpine, the Danish national database for spine operated patients. STATA is used for statistical work. The operations are performed by specialists in spine surgery. Well-known and validated questionnaires are used for assessment of mental and physical health and for quality of life, SF-36, ODI, and EuroQol. VAS used for pain estimation and the walking distance is assessed by questionnaire.
Findings / Results: The VAS score for back pain and leg pain is reduced significantly one year after surgery. Furthermore the mental and physical score of SF-36 and the ODI is improved, the distance of walking is increased and the quality of life, estimated by EuroQol, is improved significantly one year after surgery.
Conclusions: For patients with spinal stenosis and disabling symptoms as pain, numbness, parasthesia and loss of motor control, decompression relieves the symptoms and the patients improve in both mental and physical health.