Pedicle subtraction osteotomies (PSO) in the lumbar spine for sagittal deformities

Abstract

Introduction The narrow correlation between sagittal alignment parameters and clinical outcomes has been widely established, demonstrating that improper sagittal alignment is a clinical condition that is associated with increased pain and limitations in patients' functional ability. Indication Lumbar pedicle subtraction osteotomy (PSO) is indicated in the treatment of large sagittal (more than 25°o f rigid loss of lordosis) deformities of the lumbar spine or its combination with coronal deformity, especially when they are rigid. Indication should be based on careful assessment of the severity of symptoms, functional impairment, functional expectations of the patient, general clinical condition and surgical and anesthesiological team experience. Risk should be carefully assessed and discussed to obtain appropriate informed consent. Surgical procedure Surgical planning includes selection of the safest levels for the upper and lower instrumented vertebra, site of the osteotomy, modality of fixation, and, most importantly angular value of the correction goal (target lumbar lordosis). Failure to adequately obtain the necessary amount of sagittal correction is the most frequent cause of failure and reoperation. Conclusion PSO is a valuable surgical procedure in correction of severe hypolordosis (=relative kyphosis) in the lumbar spine. It is a demanding procedure for the surgeon, the anesthesiologist and the intensive care team. Although its complication rate is high, it has a substantial positive impact in the quality of life of patients, including the elderly.

Correction of severe spinopelvic mismatch: decreased blood loss with lateral hyperlordotic interbody grafts as compared with pedicle subtraction osteotomy

“…9,12 There are numerous disadvantages associated with the PSO, however, including increases in operative time and blood loss, as well as an increase in risk of neurological dysfunction, morbidity, and mortality.…”

“…4,18,33,34,[63][64][65] The traditional surgical approach for lordosis restoration in patients with severe spinopelvic mismatch has involved the use of the 3-column pedicle subtraction osteotomy (PSO). 9,12,18,19,21,76 While ABBREVIATIONS ACR = anterior column realignment; ALIF = anterior lumbar interbody fusion; ALL = anterior longitudinal ligament; ASD = adult spinal deformity; BMP = bone morphogenetic protein; EBL = estimated blood loss; LL = lumbar lordosis; LLIF = lateral lumbar interbody fusion; LOS = length of stay; OR = operating room; PI = pelvic incidence; PSO = pedicle subtraction osteotomy; TLIF = transforaminal lumbar interbody fusion. Patients who had a PSO in the setting of a preexisting fusion that spanned more than 4 levels were excluded.…”

Sagittal Alignment in Spinal Deformity: Implications for the Non-Operative Care Practitioner

“…A significantly higher osteotomy rate was reported with increasing positive sagittal malalignment and a PI-LL mismatch [29][30][31]. Iliac fixation was more commonly used as global alignment became increasingly positive.…”

“…The literature review of this section demonstrates that the sagittal plane is vital to understanding pain and disability in patients with ASD, and that SVA, PT, and PI-LL mismatch are the main drivers that affect disability and decreased function [27][28][29][30][31][32]. Becoming proficient in defining radiographically the above parameters, values and limits, can help guide a better therapeutic decision-making process conservatively and operatively with the aim and focus on maintaining or creating the best sagittal alignment for the individual that will improve function, as well as decrease pain and disability.…”

Minimally invasive two-column correction of T10–L5 three-dimensional spinal deformity

“…Mini-open, lateral, retroperitoneal, transpsoas approaches to the thoracolumbar spine are increasingly being used as alternatives to conventional approaches, with minimization of operative morbidity [1][2][3][4][5][6][7][8][9]. However, many times open posterior instrumentation is used in conjunction with these less invasive anterior approaches for, in particular, deformity cases, obviating the less-invasive nature of the anterior approach with substantial posterior morbidity.…”