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Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_15 | Pages 13 - 13
1 Oct 2014
Ohlin A Abul-Kasim K
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During the last decade or more, the anchors used for instrumentation in scoliosis surgery are predominantly transpedicular screws, according to Suk. The long term radiographical feature of screw fixation after scoliosis surgery is not previously studied.

A consecutive series of 81 cases with AIS operated on with an all screw construct has been studied by means of low dose CT postoperatively and at 2 years postoperatively. There were 67 females and 14 males, with a mean age of 18.3 ± 3 years.

In 26 / 81 (32 %) there were signs of loosing of one or more screws, at a maximum 3 screws. We observed loosened screws in the upper thoracic region in 16 cases, in the thoracolumbar 6 and in lumbar area in 4. Mean pre-op Cobb angle was 56 in cases of loosening and 53 of intact screw fixation (n.s.), the correction rate was 69% in loosened vs 70% among intact screws (n.s.). In males there were signs of loosening in 8/14 (57%) and in females 18/67 (27%). Among cases with loosening, 14% had suboptimal screw positioning postoperatively, in intact cases it was observed in 11% (n.s.). In the whole group there were signs of suboptimal screw positioning 12%. Clinically, 1 case had a loosened L4 screw replaced; and at all 21/26 had no complaints and 5/26 reported minor pain or discomfort. 1/26 had a minor proximal junctional kyphosis about 10°, in 3/26 there was a pull-out of some few mms. With plain radiography loosening could be observed in 11/26 cases; 5 were in the lumbar region.

In a consecutive series of 81 adolescents with idiopathic scoliosis who had underwent scoliosis surgery according to Suk, one third showed, 2 years after the intervention, some minor screw loosening, assessed by low dose CT. One patient had one lumbar screw replaced and only 5 patients reported minor discomfort. Males were more prone to develop screw loosening.


Background

Balloon kyphoplasty (BKP) is a minimally invasive cementing procedure, occasionally used in patients with painful vertebral compression fractures (VCF). In this multicenter Swedish RCT, we evaluated the cost-effectiveness of BKP compared with standard medical treatment, Control, in osteoporotic patients with acute/sub-acute VCF (<3 months). In a multicenter European clinical study (FREE trial) including 300 patients and FU after one year, BKP was suggested to be a safe and effective procedure in selected patients. The current study includes the Swedish patients in the FREE trial Method: Hospitalized patients with a back pain level of at least 4/10 on a visual analogue scale due to of VCF between Th5–L5 (confirmed by MRI) were randomized to either BKP or Control treatment (standard medical treatment with pain medication and functional support). All VCF-associated costs (hospital, primary care, rehabilitation, community care, private care, pharmaceuticals, assistance by relatives, work absenteeism) were identified and reported from the perspectives of cost to society, and costs to the healthcare system. Primary outcome was quality of life change (QoL) measured with the preference based EQ-5D instrument. The accumulated quality adjusted life years gained (QALYs) and costs per QALY gained was assessed. Willingness to pay (WTP) for a QALY gained in Sweden was estimated at approximately SEK 600,000 (EURO 62,500). Sensitivity analyses were performed.

Results

Between February 2003 and December 2005, 70 patients were randomized to BKP (n=35) or to standard medical treatment (n=35). Three patients in the Control group declined to participate in an economic evaluation, and only patients answering EQ-5D at all FU occasions (1-3-6-12-24 months) were included in the analyses, leaving in all 63 patients, BKP=32, Control=31. Baseline data were similar. The mean age in the BKP group was 72 years (71% women) vs. 75 years (78% women) in the Control group. Baseline difference in QoL was adjusted for using statistical methods. There were no cross overs. Four patients in the BKP group and three patients in the Control group died within two years of causes not related to the VCF. Costs were collected using “cost diaries” in mailed questionnaires after 1-3-6-12-18-24 months. Costs and EQ-5D values (0 at FU after death) were carried forward. Total mean societal cost per patient for BKP and Control was SEK 160,017 (SD 151,083) and SEK 84,816 (SD 40,954), respectively. The difference was significant 75,198 (95% CI 16,037 to 120,104). The accumulated mean difference in QALYs was 0.085 (−0.132 to 0.306) units in favour of BKP. Cost per QALY gained using BKP was SEK 884,682 (EURO 92,154) with high uncertainty assessed using the bootstrapping technique, and demonstrated on the cost-effectiveness plane and on the acceptability curve. When the EQ-5D values from all patients in the FREE trials were included in a sensitivity analysis, cost/QALY was SEK 359,146 (EURO 37,411) Conclusion: Costs were significantly higher for BKP compared with standard medical treatment, with no significant difference in QALYs gained. In this selected patient population with vertebral compression fracture due to osteoporosis, BKP could not be concluded as cost-effective after two years


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXI | Pages 18 - 18
1 Jul 2012
Ohlin A Abul-Kasim K Söderberg M
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Study design

Retrospective study.

Objectives

To optimise the radiation doses and image quality for the cone-beam O-arm surgical imaging system in spinal surgery.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXI | Pages 19 - 19
1 Jul 2012
Ohlin A
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Pedicle screws as the principal anchors of instrumentation in correction of scoliosis as described by Suk 15 years ago have now gained a wide acceptance among deformity surgeons. Pedicles in the concavity of the major as well as compensatory curves are often dysplastic making screw placement occasionally problematic.

In cases of dural ectasia with dystrophic pedicles, the transpedicular screw anchorage is sometimes impossible. In 2009 Gardner et al. presented a case of NF-1 with a troublesome cervico-thoracic kyphosis where they created distal anchors by means of laminar screw fixation. In the presentation of this case, the idea is further developed.

Case

A 14 year old girl without any obvious syndromic feature underwent surgery for a 70 degree thoracic scoliosis. A preoperatively MRI showed a dural ectasia. A preoperative low dose–CT revealed dystrophic pedicles from Th4 to L4, making transpedicular screw placement problematical.

The operation was performed with the aid of an O-arm. At all levels from Th2 – L2 laminar screw fixation was used.

Postoperatively, low-dose CT showed excellent screw positioning with the exceptiuon of one proximal screw which compromised a foramem but, without any symptoms.

The postoperative course was quite uneventful and the patient was discharged at day 5days postoperatively. The correction rate was 70%.

Conclusion

In cases of scoliosis with severe dystrophic pedicles, the use of laminar screws is a good alternative to problematic transpedicular screw placement.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 231 - 231
1 May 2006
Ohlin A
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Background: Patients with adolescent idiopathic scoliosis (AIS) exceeding fifty degrees or more at maturity are at risk for continuous progression. For curves in the thoracolumbar or lumbar region vertebral olisthesis, with severe low back pain with or without radicular pain, may result. Conventional techniques with anterior, posterior or combined approaches often fail to achieve a good alignment. The technique described by Bradford employing a shortening osteotomy at the apical segments can be used in very stiff curves with translations.

Methods: Three women with AIS and successive curve deterioration were treated by means of shortening osteotomy at our institution. The mean age was 40 (48–35) years and the follow up was 26 (60–8) months. The resected vertebrae were L1 in two cases and L2 in one. The operations were staged, initially anterior discectomies were performed. A flap of the vertebral wall was then raised and a total resection of the vertebral body and the convex pedicle was undertaken. After protection of the dual sac with a Spongostan film, the harvested bone was impacted into the defect. One week later, the remnants of the vertebra were removed posteriorly following temporary stabilization. Correction was achieved by compression.

Results: Two osteotomies united and the patients are pain free, in good balance and back at work. The other case had a temporary partial drop foot on one side, however radiographically is progressing well and she remains in rehabilitation. There have been no implant related complications.

Conclusion: Shortening osteotomy appears to be a good technique when treating adult patients with late rigid, painful scoliotic deformities of the thoracolumbar region.