Cranial facet joint violations by percutaneously placed pedicle screws adjacent to a minimally invasive lumbar spinal fusion.
ABSTRACT Protecting cranial facet joint is a modifiable risk factor that may decrease the incidence of adjacent segment disease after lumbar spinal fusion. Percutaneously instrumented screws may more frequently violate cranial facet joints because of the potential limitation of screw entry site selection. To our knowledge, however, there is no study that has evaluated the cranial facet joint violations adjacent to minimally invasive lumbar fusion related to percutaneously placed pedicle screws.
We investigated the incidence and relating factors of cranial facet joint violations by percutaneous pedicle screws.
A retrospective study of prospectively collecting data.
The sample comprises 184 pedicle screws percutaneously placed at the cranial fusion segments in 92 patients who underwent minimally invasive lumbar spinal fusion.
The facet joint violations adjacent to a cranial fusion segment were examined on the postoperative computed tomography (CT) scans.
Two independent observers retrospectively examined all the postoperative CT images. A facet joint was considered violated if any of the following situations were encountered: pedicle screw clearly within the facet joint; pedicle screw head clearly within the facet joint; and pedicle screw and/or screw head within 1 mm from or abutting the facet joint, without clear joint involvement.
The incidence of the violations was 50% (46/92) of all patients and 31.5% (58/184) of all screws, which were significantly higher than the previously reported rates with the traditional open procedure (50% vs. 23.5% of all patients, p<.001; 31.5% vs. 15.2% of all screws, p<.001). The violations occurred approximately 3.3 times more frequently at the most cranial pedicle screws of L5 pedicle than at the other pedicles (70.8% vs. 42.6%, odds ratio [OR]=3.3, p=.021). Logistic regression analysis revealed a significant trend toward reducing the incidence of the violations as increasing the year of surgery (OR=0.7, p=.008). The incidence showed no significant relationships with patients' age, gender, body mass index, preoperative diagnosis, the number of fused segments, or the side of screw placement.
Our data raise a concern about the higher incidence of cranial facet joint violations by percutaneously placed pedicle screws than that previously reported rates by traditionally instrumented screws. Furthermore, more care should be taken to avoid cranial facet joint violations when the surgeon is a novice to percutaneous pedicle screw placement and/or minimally invasive fusion surgery is considered at the L5-S1 segment.
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ABSTRACT: Object A reported risk factor for adjacent-segment disease is injury to the superior facet joint from pedicle screw placement. Given that the facet joint is not typically visualized during percutaneous pedicle screw insertion, there is a concern for increased facet violation (FV) in minimally invasive fusion procedures. The purpose of this study was to analyze and compare the incidence of FV among patients undergoing minimally invasive transforaminal lumbar interbody fusion (MITLIF) and open transforaminal lumbar interbody fusion (TLIF). The impact of O-arm navigation compared with traditional fluoroscopy on FV in MITLIF is also assessed, as are risk factors for FV. Methods The authors identified a consecutive population of patients who underwent MITLIF with percutaneous pedicle screw placement, as well as a matched cohort of patients who underwent open TLIF. Postoperative CT imaging was assessed to determine intraarticular FV due to pedicle screw placement. Patients were stratified into minimally invasive and open TLIF groups. Within the MITLIF group, the authors performed a subanalysis of image guidance methods used in cases of FV. Two-tailed Student t-test, ANOVA, chi-square testing, and logistic regression were used for statistical analysis. Results A total of 282 patients were identified, with a total of 564 superior pedicle screw placements. The MITLIF group consisted of 142 patients with 284 screw insertions. The open TLIF group consisted of 140 patients with 280 screw insertions. Overall, 21 (7.4%) of 282 patients experienced FV. A total of 21 screws violated a facet joint for a screw-based FV rate of 3.7% (21 of 564 screws). There were no significant differences between the MITLIF and open TLIF groups in the percentage of patients with FV (6.3% vs 8.6%) and or the percentage of screws with FV (3.2% vs 4.3%) (p = 0.475 and p = 0.484, respectively). Further stratifying the MI group into O-arm navigation and fluoroscopic guidance subgroups, the patient-based rates of FV were 10.8% (4 of 37 patients) and 4.8% (5 of 105 patients), respectively, and the screw-based rates of FV were 5.4% (4 of 74 screws) and 2.4% (5 of 210 screws), respectively. There was no significant difference between the subgroups with respect to patient-based or screw-based FV rates (p = 0.375 and p = 0.442, respectively). The O-arm group had a significantly higher body mass index (BMI) (p = 0.021). BMI greater than 29.9 was independently associated with higher FV (OR 2.36, 95% CI 1.65-8.53, p = 0.039). Conclusions The findings suggest that minimally invasive pedicle screw placement is not associated with higher rates of FV. Overall violation rates were similar in MITLIF and open TLIF. Higher BMI, however, was a risk factor for increased FV. The use of O-arm fluoroscopy with computer-assisted guidance did not significantly decrease the rate of FV.Journal of neurosurgery. Spine 02/2013; · 1.61 Impact Factor
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ABSTRACT: OBJECTIVE: To compare the outcomes of minimally invasive percutaneous short-segment pedicle instrumentation (SSPI) with that of trans-spatium intermuscular SSPI on thoracolumbar mono-segmental vertebral fracture without neurological compromise. METHODS: A total of 39 patients with thoracolumbar mono-segmental vertebral fracture without neurological deficit receiving treatment between January 2009 and July 2011 were enrolled. Percutaneous SSPI was performed for 18 patients (the percutaneous group), and trans-spatium intermuscular SSPI was performed for 21 patients (the trans-spatium intermuscular group). Peroperative indices, intraoperative radiation exposure time, postoperative and follow-up lumbodorsal pain, function scores, and radiological data were compared. RESULTS: The percutaneous group had significantly less intraoperative blood loss and less severe postoperative pains, but suffered significantly longer fluoroscopy time and higher hospitalization costs compared with the trans-spatium intermuscular group. No significant difference was observed in operating time. All patients were followed up for 17.3±9.2 months (ranging from 5 to 35 months). No significant differences were observed between the two groups in terms of postoperative relative vertebral height (RVH) and regional kyphotic angle (RKA), as well as last follow-up RVH, RKA, lumbodorsal pain, and Oswestry disability index. CONCLUSION: Percutaneous SSPI has the virtues of less intraoperative blood loss and less severe pains in the treatment of thoracolumbar mono-segmental vertebral fracture without neurological deficit. When compared with trans-spatium intermuscular SSPI, it results in longer intraoperative radiation exposure time and a higher surgery cost. To us, percutaneous SSPI has no advantage over trans-spatium intermuscular SSPI in therapeutic outcomes. LEVEL OF EVIDENCE: Level IV. Retrospective study.Orthopaedics & Traumatology Surgery & Research 04/2013; · 1.06 Impact Factor
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ABSTRACT: STUDY DESIGN:: Retrospective study. OBJECTIVES:: To investigate the clinical feasibility and outcomes from direct lateral interbody fusion (DLIF) using autogenous bone grafts and percutaneous posterior instrumentation (PPI) for infectious spondylitis. SUMMARY OF BACKGROUND DATA:: As one of the minimally invasive techniques, PPI has been attempted for various degenerative lumbar spine disorders combined with anterior lumbar interbody fusion or transforaminal lumbar interbody fusion. PPI has been played more roles recently as an internal fixation method for infectious spondylitis. However, the clinical outcomes of DLIF using an autogenous bone graft combined with PPI for infectious spondylitis have been rarely reported. MATERIAL AND METHODS:: Sixteen patients (mean age, 60.3±18.8▒y) who suffereed from pyogenic spondylitis underwent single-stage DLIF using an autogenous iliac bone graft combined with PPI. Clinical and radiological outcomes were evaluated by visual analogue scale (VAS), Oswestry disability index (ODI) and eradication of primary disease. Radiological outcomes were evaluated by changes of affected segmental lordosis and fusion status. RESULTS:: Bony fusion and eradication of primary disease were obtained in all patient except one case during the follow-up (mean, 31.3±13.1▒mo; range 14 - 46▒mo). Preoperative VAS (7±1.2) and ODI (61.3±5.4) scores improved significantly at the last follow-up (VAS, 3.4±1.5; ODI, 32.3±15.4). C-reactive protein normalized at postoperative 20.1±0.7 days (range, 15 - 28▒d). Although height and lordosis in the affected segment were restored by surgery, all patients showed loss of the restored lordosis and height at the final follow-up. Loss of the restored lordosis and height were related to subsidence of the grafted bone. CONCLUSIONS:: Minimally invasive PPI followed by debridement and DLIF was a feasible surgical alternative in our consecutive 16 cases of pyogenic spondylitis. In most cases, the subsidence of anteriorly grafted fusion was inevitable despite successful fusion and eradication of the primary lesion.Journal of spinal disorders & techniques 08/2012; · 1.21 Impact Factor