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: Adjacent segment degeneration is a long-term complication of arthrodesis. However, the incidence of adjacent segment degeneration varies widely depending on the patient's age and underlying disease and the fusion techniques and diagnostic methods used. We determined (1) the frequency of adjacent segment degeneration and increased lordosis on imaging tests, (2) the frequency and severity of clinical sequelae of these findings, including revision surgery, and (3) the sequence of degeneration and risk factors for degeneration. Seventy-three patients underwent anterior lumbar interbody fusion for low-grade isthmic spondylolisthesis at one institution between October 2000 and February 2002. Forty-nine (67%) of the original patients had complete radiographic and clinical followup for 10 years. CT and MRI were performed at 5 years and 10 years in all cases. The disc height, sagittal profiles, and facet and disc degeneration at adjacent levels were examined to identify radiographic and clinical adjacent segment degeneration. Mean followup was 134.2 months (range, 120-148 months). Cranial segment lordosis increased (from 14.8° to 18.5°; p < 0.001), while caudal segment lordosis changed little (from 16.4° to 17.3°). Radiographic and clinical adjacent segment degeneration occurred in 19 (38.8%) and six (12.2%) patients, respectively, and two patients (4.1%) underwent revision surgery. Patients with adjacent segment degeneration had more advanced preexisting facet degeneration than patients without adjacent segment degeneration (odds ratio: 18.6; 95% CI, 1.97-175.54, p = 0.01). Acceleration of disc and facet degeneration occurred in 4.1% and 10.2%, respectively. Adjacent segment degeneration requiring surgery is rare, although radiographic adjacent segment degeneration is common after anterior lumbar interbody fusion for isthmic spondylolisthesis. The only risk factor we found was preexisting facet degeneration of the cranial segment. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.Clinical Orthopaedics and Related Research 08/2013; · 2.79 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: The role of fusion of lumbar motion segments for the treatment of intractable low back pain (LBP) from degenerative disc disease (DDD) without deformities or instabilities remains controversially debated. Total lumbar disc replacement (TDR) has been used as an alternative in a highly selected patient cohort. However, the amount of long-term follow-up (FU) data on TDR is limited. In the United States, insurers have refused to reimburse surgeons for TDRs for fear of delayed complications, revisions, and unknown secondary costs, leading to a drastic decline in TDR numbers. To assess the mid- and long-term clinical efficacy as well as patient safety of TDR in terms of perioperative complication and reoperation rates. Prospective, single-center clinical investigation of TDR with ProDisc II (Synthes, Paoli, PA, USA) for the treatment of LBP from lumbar DDD that has proven unresponsive to conservative therapy. Patients with a minimum of 5-year FU after TDR, performed for the treatment of intractable and predominant (≥80%) axial LBP resulting from DDD without any deformities or instabilities. Visual analog scale (VAS), Oswestry Disability Index (ODI), and patient satisfaction rates (three-scale outcome rating); complication and reoperation rates as well as elapsed time until revision surgery; patient's professional activity/employment status. Clinical outcome scores were acquired within the framework of an ongoing prospective clinical trial. Patients were examined preoperatively, 3, 6, and 12 months postoperatively, annually from then onward. The data acquisition was performed by members of the clinic's spine unit including medical staff, research assistants, and research nurses who were not involved in the process of pre- or postoperative decision-making. The initial cohort consisted of 201 patients; 181 patients were available for final FU, resembling a 90.0% FU rate after a mean FU of 7.4 years (range 5.0-10.8 years). The overall results revealed a highly significant improvement from baseline VAS and ODI levels at all postoperative FU stages (p<.0001). VAS scores demonstrated a slight (from VAS 2.6 to 3.3) but statistically significant deterioration from 48 months onward (p<.05). Patient satisfaction rates remained stable throughout the entire postoperative course, with 63.6% of patients reporting a highly satisfactory or a satisfactory (22.7%) outcome, whereas 13.7% of patients were not satisfied. The overall complication rate was 14.4% (N=26/181). The incidence of revision surgeries for general and/or device-related complications was 7.2% (N=13/181). Two-level TDRs demonstrated a significant improvement of VAS and ODI scores in comparison to baseline levels (p<.05). Nevertheless, the results were significantly inferior in comparison to one-level cases and were associated with higher complication (11.9% vs. 27.6%; p=.03) and inferior satisfaction rates (p<.003). Despite the fact that the current data comprises the early experiences and learning curve associated with a new surgical technique, the results demonstrate satisfactory and maintained mid- to long-term clinical results after a mean FU of 7.4 years. Patient safety was proven with acceptable complication and reoperation rates. Fear of excessive late complications or reoperations following the primary TDR procedure cannot be substantiated with the present data. In carefully selected cases, TDR can be considered a viable treatment alternative to lumbar fusion for which spine communities around the world seem to have accepted mediocre clinical results as well as obvious and significant drawbacks.The spine journal: official journal of the North American Spine Society 01/2014; · 2.90 Impact Factor