Preventing proximal junctional failure in long segmental instrumented cases of adult degenerative scoliosis using a multilevel stabilization screw technique

Abstract

Background:The authors sought to demonstrate the safety and effectiveness of the multilevel stabilization screw (MLSS) technique in decreasing the incidence of proximal junctional failure in long segmental instrumented fusions for adult degenerative scoliosis.Methods:Institutional review board approval was obtained and all patients with adult spinal deformity who underwent the MLSS technique were analyzed. A neuro-radiologist and spine-focused neurosurgeon not involved with the surgical treatment performed radiographic analysis. Proximal junctional angle was defined as the caudal endplate of the upper instrumented vertebra (UIV) to the cephalad endplate of two supradjacent vertebrae above the UIV. The UIV is defined as the most cephalad vertebra completed captured by the instrumentation. Abnormal proximal junctional kyphosis (PJK) was defined as proximal junctional sagittal Cobb angle >10 degrees and proximal junction sagittal Cobb angle at least 10 degrees greater than the preoperative measurement. The presence of both is criteria necessary to be considered abnormal.Results:Twenty patients with degenerative scoliosis underwent the MLSS technique with the upper-instrumented vertebrae in the proximal thoracic spine. Fifteen patients met inclusion criteria with greater than 12 months radiographic and clinical follow up. Three patients were excluded due to lack of follow up imaging and two patients were excluded due to the inability to measure the UIV. Age range was 44–84 years with a mean of 66. Eleven of the 15 patients were over the age of 60 at the time of surgery. The male-to-female ratio was 4:11. Body mass index (BMI) range was 24–44 with a mean of 31.5 units. The follow up period ranged from 14 to 58 months with an average follow up of 30 months. The mean change in Cobb angle at the proximal junction was 4.00 degrees with a range from -0.92 to 9.13 degrees. There were no fractures or instrumentation failures at or near the proximal junction. There was no revision surgeries performed for proximal junctional failure. Retrospective clinical questionnaires revealed that surgical expectations were met in 15 of 19 patients surveyed, 79%. One patient was not reachable for a postoperative phone interview. In patients who were not satisfied with their overall experience, the change in Cobb angle ranged from -0.92 to 9.13 degrees with an average change of 3.90 degrees. Whereas patients reporting an overall positive experience had a change in Cobb angle range from -0.12 to 8.07 degrees with an average change of 4.05 degrees.Conclusion:PJK and failure are well-recognized suboptimal outcomes of long-segmental fusions of the thoracolumbar spine that can lead to significant neurological morbidity and costly revision surgeries. With no known proximal junction failures to date, the MLSS technique has shown promising results in preventing adverse proximal junctional conditions and can be safely performed under fluoroscopy guidance. Future direction includes a comparative study establishing the relative risk of developing PJK ...

Results of Using a Novel Percutaneous Pedicle Screw Technique for Patients with Diffuse Idiopathic Skeletal Hyperostosis-The Single or Double Endplates Penetrating Screw (SEPS/DEPS) Technique

“…They reported that transvertebral screw fixation had good fixation force similar to the traditional PS fixation, and it can be a viable therapeutic option for fixation in a salvage procedure, if PS insertion is not possible 17) . Sandquist et al reported on the multilevel stabilization screw technique for decreasing the incidence of proximal junctional failure in long segmental instrumented fusions for adult degenerative scoliosis 18) . These reports suggested that transvertebral screws are a useful device to obtain favorable surgical outcomes.…”

Instrumentation Techniques to Prevent Proximal Junctional Kyphosis and Proximal Junctional Failure in Adult Spinal Deformity Correction: A Systematic Review of Clinical Studies

“…For each study, PJK incidence, Revision Rate for PJK (RR), PJF incidence, reported clinical outcomes and complications were reported in Table 3. Twelve of the included studies reported on PJK incidence, 28-31,33-36,38,39,41,43 10 on revision rate for PJK, 28-31,33,35,36,38,39,41 13 on PJF incidence, 29,32,34-40,42-45 5 on any clinical outcome measure 28,38,40,41,45 and 10 on complications. 28-30,35-39,41,45 Four studies 28-30,37,45 did not elaborate on the type of complications, and could thus not be converted to the classification of Glassman et al 27 If reported, the clinical outcome measures were further elucidated in Table 4.…”

“…Of the included studies, 4 were prospective- and 14 were retrospective cohort studies. The studies that were included reported on tether fixation, 28 - 34 prophylactic 2-level vertebroplasty (2-PVP), 32 , 35 - 40 transverse process hooks (TPH), 32 , 41 , 42 flexible rods (FR), 43 multilevel stabilization screw (MLSS), 44 and sublaminar tapes (ST). 45 These surgical techniques are schematically illustrated in Figure 1 .…”

“…For each study, PJK incidence, Revision Rate for PJK (RR), PJF incidence, reported clinical outcomes and complications were reported in Table 3. Twelve of the included studies reported on PJK incidence, [28][29][30][31][33][34][35][36]38,39,41,43 10 on revision rate for PJK, [28][29][30][31]33,35,36,38,39,41 13 on PJF incidence, 29,32,[34][35][36][37][38][39][40][42][43][44][45] 5 on any clinical outcome measure 28,38,40,41,45 and 10 on complications. [28][29][30][35][36][37][38][39]4...…”

“…The rod-material used for the spinal fusion was not reported in 15 studies, [28][29][30][31][33][34][35][36][37][38][39][40][41][42]44 and for the remaining 3 studies this was cobalt chromium, stainless steel or titanium. 32,43,45 Five studies did not mention if other surgical interventions were performed concomitantly.…”