Transpedicular decompression and pedicle subtraction osteotomy (eggshell procedure): a retrospective review of 59 patients

Clinical and radiographic outcomes of 19 proximal thoracic pedicle subtraction osteotomies for adult spinal deformity: a case series

PURPOSE

To present a detailed analysis of postoperative clinical and radiographic outcomes of patients who underwent proximal thoracic pedicle subtraction osteotomy (PSO) for adult spinal deformity.

METHODS

A retrospective chart review was performed on 19 patients who underwent proximal thoracic (T2-T4) PSO between January 2018 and December 2021. Baseline patient characteristics, complications and radiographic outcomes were collected. Radiographic outcomes including thoracic kyphosis correction, overall segment correction, and global sagittal balance correction were measured using preoperative and postoperative radiographs.

RESULTS

19 patients with an average age of 66.9 ± 8.3 years underwent thoracic PSO, with 94.7% (n = 18) being females, in the setting of revision surgery. The mean thoracic kyphosis correction was 20.4 ± 8.5°. Overall segmental correction had a mean of 16.2 ± 3.9°. Global sagittal balance correction was an average of 13.9 ± 23.2 mm (mm). The median hospital stay was 4.0 (IQR: 3.0) days with a median of 1.0 (IQR: 2.0) days in the intensive care unit. 36.8% (n = 7) of patients had a major complication within 30 days: proximal junction kyphosis (PJK) (2), neurologic deficits (2), pneumonia (1), cardiopulmonary (1), death (1). 47.4% (n = 9) of patients had a major complication within 2 years: PJK (5), neurologic deficits (2), wound dehiscence/infection (1), pneumonia (1), cardiopulmonary (1), death (2). Average follow up was 636 (range: 43-1320).

CONCLUSION

While thoracic PSO can achieve successful radiographic and clinical outcomes, it is also associated with a high risk of potential major complications and mortality, such as instrumentation or junctional failure and neurologic deficits.

Postoperative complications following Schwab-grade-I versus Schwab-grade-II PCO in treating severe rigid kyphoscoliosis patients: comparative matched-group outcomes with minimum 2-year follow-up

BACKGROUND CONTEXT

Standard partial facetectomies, (Smith-Petersen Osteotomy, (SPO), (Schwab-grade-I) and complete facet resection also known as Ponte osteotomy, (PO), (Schwab-grade-II) are narrowly akin and collectively appreciated as posterior column shortening osteotomies (PCOs). The former is considered a gentler osteotomy grade than the latter. The spine literature provides very little information on their comparison regarding perioperative complications and major curve correction rate outcomes.

PURPOSE

To determine whether Schwab-grade-I PCO (SPO) and Schwab-grade-II PCO (PO) are comparably safe in the surgical management of severe rigid scoliosis or kyphoscoliosis patients.

STUDY DESIGN/SETTING

Retrospective single-center comparative clinical study.

PATIENT SAMPLE

A total of 38 patients with severe rigid scoliosis or kyphoscoliosis were propensity score matched in this study, (SPO-treated); n=21 (55.30%) and (PO-treated); n=17 (44.70%), who underwent primary spinal deformity corrective surgery, respectively.

OUTCOME MEASURES

Outcomes included demographics, baseline pulmonary functional outcomes, perioperative complications incidence, hospital costs, Oswestry disability index (ODI), and the Scoliosis Research Society-22 (SRS-22) questionnaire scores.

METHODS

Following approval by the Institutional Review Board (IRB) of Beijing Chaoyang Hospital-Affiliated Capital Medical University in Beijing, out of a total of 82 consecutive surgical patients with complete data demonstrating severe and/or rigid spinal deformity, a pool of 38 of the 82 (46.3%) propensity-matched adult (≥18 years) patients with severe rigid scoliosis or kyphoscoliosis defined with a preoperative major curve magnitude of ≥80° on anteroposterior plain radiographs, and flexibility of <25% on bending plain radiographs who underwent primary spinal deformity corrective surgery were retrospectively evaluated. The patients were dichotomized into two osteotomy groups: standard (partial) facetectomy (SPO-treated), n=21 with an average age of 24.67 years, (Schwab-grade-I PCO) and complete facet excision, (PO-treated), (ie, Schwab-grade-II PCO), n=17 with an average age of 23.12 years. The minimum follow-up period was 2 years. Primary outcomes included baseline demographics and clinical features. Secondary outcomes included perioperative [intraoperative, immediate, and 2-year postoperative] complication rates. Tertiary outcomes included perioperative ODI and SRS-22 scores. Statistical analyses were carried out by Student t-test and Pearson's Chi-square test (Fisher's Exact Test), through Python statistical software package. Statistical significance was set at (p<.05).

RESULTS

Of the 38 matched severe rigid scoliosis or kyphoscoliosis patients, 55.30% (n=21) were SPO-treated and 44.70% (n=17) were PO-treated patients, respectively. The overall average age of patients was 23.97 years, with a female incidence of 76.32%. Major curve correction rates were 49.19% and 57.40% in SPO-treated and PO-treated patients, respectively, (p>.05). Immediately following surgery, comparable overall complication rates of 28.57% (n=6/21) versus 29.41% (n=5/17) were observed in the SPO-treated and PO-treated patients, respectively, (p=.726). We observed incidences of 9.52%, (n=2/21) versus 5.88%, (n=1/17) for surgical intensive care unit (SICU) admission, and incidences of 4.76%, (n=1/21) versus 5.88%, (n=1/17) for cardiopulmonary events in SPO-treated versus PO-treated patients following corrective surgery, respectively, (p>.05). The incidences of neurological deficits in the SPO-treated and PO-treated patients were respectively, 14.29%, (n=3/21) versus 17.65%, (n=3/17) immediately following surgery, (p>.05), and 0.00%, (n=0/21) in SPO-treated versus 14.28%, (n=3/21) in PO-treated patients at ≥2 years postoperative, (p<.05). Among the three patients that reported neurological deficits in the PO-treated group at ≥2 years postoperative, two patients had pre-existing baseline neurological deficits. The ODI score in the PO-treated group was significantly inferior at a minimum 2-year follow-up, (p<.05).

CONCLUSIONS

In the current study, both SPO-treated and PO-treated patients demonstrated statistically comparable surgical complications immediately following corrective surgery. Severe rigid kyphoscoliosis patients with preexisting baseline neurological deficits were more inclined to sustain neurological morbidity following corrective surgery. PCO corrective techniques are warranted as safe options for treating patients with severe rigid spine deformity phenotypes.

Comparison of staged lateral lumbar interbody fusion combined two-stage posterior screw fixation and two osteotomy strategies for adult degeneration scoliosis: a retrospective comparative study

AIMS

The commonly used treatments of adult degeneration scoliosis (ADS) were posterior long segment screw fixation with osteotomies. Recently, lateral lumbar intervertebral fusion combined two-stage posterior screw fixation (LLIF + PSF) as a new strategy without osteotomy. Herein, this study aimed to compare the clinical and radiological outcomes among LLIF + PSF and pedicle subtraction osteotomy (PSO), posterior column osteotomies (PCO).

METHODS

Totals of 139 ADS patients underwent operation with 2 years longer follow-up visit between January 2013 and January 2018 in Ningbo No.6 Hospital were enrolled into this study. 58 patients were included in PSO group, 45 in PCO group and 36 in LLIF + PSF group, The clinical and radiological data were reviewed from medical records. Baseline characteristic, perioperative radiological data (sagittal vertical axis (SVA), coronal balance (CB), Cobb angle of Mian curve (MC), Lumbar lordosis (LL), pelvic tilt (PT) and pelvic incidence-lumbar lordosis mismatch (PI-LL)), clinical outcomes (VAS of back and leg, Oswestry disability index (ODI) and Scoliosis Research Society 22-question Questionnaire (SRS-22)) and complications were evaluated and compared.

RESULT

There were no significantly difference in baseline characteristics, preoperative radiological parameters and clinical outcomes among three groups. LLIF + PSF group was significantly shorter in operation time than other two groups (P < 0.05), whereas significant longer hospital stay was observed in LLIF + PSF group (P < 0.05). As for radiological parameters, LLIF + PSF group had significantly improvement in SVA, CB, MC, LL and PI-LL (P < 0.05). Moreover, LLIF + PSF group achieved significantly less correction loss in SVA, CB and PT than PSO and PCO group (1.5 ± 0.7 VS 2.0 ± 0.9 VS 2.2 ± 0.8, P < 0.05; 1.0 ± 0.4 VS 1.3 ± 0.5 VS 1.1 ± 0.7, P < 0.05 and 4.2 ± 2.8 VS 7.2 ± 3.1 VS 6.0 ± 2.8, P < 0.05). Significantly recovery in VAS of back and leg, ODI score and SRS-22 were found among all groups, however, LLIF + PSF shown significant better clinical therapy maintain at follow-up visit than other two groups (P < 0.05). There were no significantly difference in complications among groups (P = 0.66).

CONCLUSION

Lateral lumbar interbody fusion combined two-stage posterior screw fixation (LLIF + PSF) can achieve comparable clinical therapy for adult degeneration scoliosis as osteotomy strategies. However, furthermore more studies need be taken for verifying the effect of LLIF + PSF in the future.

Innovation in proximal femoral replacement for oncology patients-A novel eggshell procedure

Purpose

Proximal femoral replacement (PFR) for oncology patients is gaining interest as a limb salvage operation due to its obvious advantages. However, almost all hip replacement surgeries including PFR, are faced with the challenge of how to reconstruct the functional musculature in an optimal way. To address the challenge, we have developed an innovative eggshell procedure and through this study we aim to investigate the specific efficacy of the procedure.

Methods

A total of 44 tumor patients with PFR surgery were incorporated into the study, including 12 who underwent the eggshell procedure and 32 who did not. General characteristics, short-term indicators, long-term indicators and complication outcomes were compared successively between the two groups of patients.

Results

No significant differences were identified in general characteristics between the two groups. Overall, in terms of both short-term and long-term indicators, the patients with eggshell procedure performed significantly superior to the patients without it. Moreover, the eggshell procedure significantly reduced the incidence of associated complications, including prosthesis dislocation and hip pain.

Conclusions

Our eggshell procedure is convenient and accessible. On the one hand, it can reduce surgical side injuries without adding additional complications, and on the other it allows to improve joint mobility and life quality while diminishing the incidence of prosthesis dislocation and hip pain. Despite it may still remain limitations, we have reasons to believe that this procedure can be further promoted and applied.

Application of vertebral body compression osteotomy in pedicle subtraction osteotomy on ankylosing spondylitis kyphosis: Finite element analysis and retrospective study

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease, with pathological characteristics of bone erosion, inflammation of attachment point, and bone ankylosis. Due to the ossified intervertebral disc and ligament, pedicle subtraction osteotomy (PSO) is one of the mainstream surgeries of AS-related thoracolumbar kyphosis, but the large amount of blood loss and high risk of instrumental instability limit its clinical application. The purpose of our study is to propose a new transpedicular vertebral body compression osteotomy (VBCO) in PSO to reduce blood loss and improve stability.

METHODS

A retrospective analysis was performed on patients with AS-related thoracolumbar kyphosis who underwent one-level PSO in our hospital from February 2009 to May 2019. A total of 31 patients were included in this study; 6 received VBCO and 25 received eggshell vertebral body osteotomy. We collected demographic data containing gender and age at diagnosis. Surgical data contained operation time, estimated blood loss (EBL), and complications. Radiographic data contained pre-operative and follow-up sagittal parameters including chin brow-vertical angle (CBVA), global kyphosis (GK), thoracic kyphosis (TK), and lumbar lordosis (LL). A typical case with L2-PSO was used to establish a finite element model. The mechanical characteristics of the internal fixation device, vertebral body, and osteotomy plane of the two osteotomy models were analyzed under different working conditions.

RESULTS

The VBCO could provide comparable restoring of CBVA, GK, TK, and LL in the eggshell osteotomy procedure (all p > 0.05). The VBCO significantly reduced EBL compared to those with eggshell osteotomy [800.0 ml (500.0-1,439.5 ml) vs. 1,455.5 ml (1,410.5-1,497.8 ml), p = 0.033]. Compared with the eggshell osteotomy, VBCO showed better mechanical property. For the intra-pedicular screw fixation, the VBCO group had a more average distributed and lower stress condition on both nails and connecting rod. VBCO had a flattened osteotomy plane than the pitted osteotomy plane of the eggshell group, showing a lower and more average distributed maximum stress and displacement of osteotomy plane.

CONCLUSION

In our study, we introduced VBCO as an improved method in PSO, with advantages in reducing blood loss and providing greater stability. Further investigation should focus on clinical research and biomechanical analysis for the application of VBCO.

Incidence and Risk Factors for Neurological Deterioration in Posterior Corrective Surgeries for Severe Angular Kyphotic Deformities: A 10-Year Institutional Retrospective Study

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

Neurological deficit is one of the dreaded complications of kyphotic deformity correction procedures. There is inconsistency in the reports of neurological outcomes following such procedures and only a few studies have analyzed the risk factors for neurological deficits. We aimed to analyze the factors associated with neurological deterioration in severe kyphotic deformity correction surgeries.

METHODS

We performed a retrospective study of 121 consecutive surgically treated severe kyphotic deformity cases (49 males, 56 females) at a single institute (May 1st 2008 to May 31st 2018) and analyzed the risk factors for neurological deterioration. The demographic, surgical and clinical details of the patients were obtained by reviewing the medical records.

RESULTS

105 included patients were divided into 2 groups: Group A (without neurological deficit) with 92 patients (42 males, 50 females) and Group B (with neurological deficit) with 13 patients (7 males, 6 females) (12.4%). Statistically significant difference between the 2 groups was observed in the preoperative sagittal Cobbs angle (p < 0.0001), operative time (p = 0.003) and the presence of myelopathic signs on neurological examination (p = 0.048) and location of the apex of deformity (p = 0.010) but not in other factors.

CONCLUSIONS

Preoperative Sagittal Cobbs angle, presence of signs of myelopathy, operative time and location of apex in the distal thoracic region were significantly higher in patients with neurological deterioration as compared to those without neurological deterioration during kyphotic deformity correction surgery. Distal thoracic curve was found to have 4 times more risk of neurological deterioration compared to others.

Pedicle Subtraction Osteotomy in Adult Spinal Deformity: Comparing Fixed Versus Flexible Sagittal Imbalance

STUDY DESIGN/SETTING

Level III-retrospective radiologic and clinical comparative study.

OBJECTIVE

This study compares the results of pedicle subtraction osteotomy (PSO) for fixed versus flexible sagittal imbalance in adult spinal deformity.

SUMMARY OF BACKGROUND DATA

The result of PSO may be different according to the flexibility of the deformity.

METHODS

Sixty-one patients who underwent PSO were enrolled with a minimum 2-year follow-up. Twenty-one patients had fixed imbalance resulting from ankylosing spondylitis and iatrogenic flatback deformity, and 40 patients had flexible imbalance resulting from degenerative spinal deformity and posttraumatic kyphosis.

RESULTS

The mean age was 54.9±9.2 years in the fixed group and 65.9±10.5 years in the flexible group (P<0.01). PSO achieved about 35 degrees of correction of kyphotic angle in both groups, but the loss of correction (LOC) was higher in the flexible group. The correction of Lumbar Lordosis was similar in both groups, at 31.7±15.4 degrees in the fixed group and 32.3±20.8 degrees in the flexible group, although the LOC was also higher in the flexible group than in the fixed group, at 9.8±12.4 and 2.7±3.5 degrees, respectively (P<0.01). The sagittal vertical axis was much more restored in the fixed group than in the flexible group (P=0.002). Postoperative complications were identified in 4 patients in the fixed group, consisting of neurological deficit and screw loosening, and in 15 patients in the flexible group, consisting of proximal junctional kyphosis, screw pullout, rod fracture, and pseudarthrosis.

CONCLUSIONS

PSO for flexible sagittal imbalance resulted in a higher LOC of the osteotomy angle, Lumbar Lordosis, and sagittal vertical axis relative to the fixed deformity. Furthermore, more complications such as implant failure developed in the flexible group.

Partial Pedicle Subtraction Osteotomy for Patients with Thoracolumbar Fractures : Comparative Study between Burst Fracture and Posttraumatic Kyphosis

Objective

To evaluate the surgical outcomes of partial pedicle subtraction osteotomy (PPSO) in patients with thoracolumbar fractures and compare the outcomes of PPSO for burst fractures with those for posttraumatic kyphosis (PTK).

Methods

From June 2013 to May 2019, 20 consecutive adult patients underwent PPSO for thoracolumbar fractures at the levels of T10 to L2. Of these patients, 10 underwent surgery for acute fractures (burst fractures), and 10 for sequelae of thoracolumbar fractures (PTK). Outcomes of PPSO were evaluated and compared between the groups.

Results

Twenty patients (each 10 patients of burst fractures and PTK) with a mean age of 64.7±11.1 years were included. The mean follow-up period was 21.8±11.0 months. The mean correction of the thoracolumbar angle was -34.9°±18.1° (from 37.8°±20.5°preoperatively to 2.8°±15.2° postoperatively). The mean angular correction at the PPSO site was -38.4°±13.6° (from 35.5°±13.6° preoperatively to -2.9°±14.1° postoperatively). The mean preoperative sagittal vertical axis was 93.5±6.7 cm, which was improved to 37.6±35.0 cm postoperatively. The mean preoperative kyphotic angle at the PPSO site was significant greater in patients with PTK (44.8°±7.2°) than in patients with burst fractures (26.2°±12.2°, p=0.00). However, the mean postoperative PPSO angle did not differ between the two groups (-5.9°±15.7° in patients with burst fractures and 0.2°±12.4° in those with PTK, p=0.28). The mean angular correction at the PPSO site was significantly greater in patients with PTK (-44.6°±10.7°) than in those with burst fractures (-32.1°±13.7°, p=0.04). The mean operation time was 188.1±37.6 minutes, and the mean amount of surgical bleeding was 1030.0±533.2 mL. There were seven cases of perioperative complications occurred in five patients (25%), including one case (5%) of neurological deficit. The operation time, surgical bleeding, and complication rates did not differ between groups.

Conclusion

In cases of burst fracture, PPSO provided enough spinal cord decompression without corpectomy and produced sagittal correction superior to that achieved with corpectomy. In case of PTK, PPSO achieved satisfactory curve correction comparable to that achieved with conventional PSO, with less surgical time, less blood loss, and lower complication rates. PPSO could be a viable surgical option for both burst fractures and PTK.

Pedicle Subtraction Osteotomy in Lateral Position: A New Strategy for Correcting Severe Thoracolumbar Kyphosis Combined with Hip Flexion Contracture in Ankylosing Spondylitis

Objective

To describe spinal osteotomy in lateral position, which might be a new strategy for correcting thoracolumbar kyphotic deformity combined with severe hip flexion contracture, and to present two cases in which this method was successfully performed.

Methods

Spinal osteotomies in lateral position were performed in two patients with severe thoracolumbar kyphosis combined with hip flexion contracture, which was not suitable for operation in the prone position. Case 1: a 33‐year‐old female AS patient still had severe hip flexion contracture due to poor rehabilitation after total hip replacement (THR). The range of movement of the hip was only about 15° in right and 10° in left. Pre‐operativethoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), and sagittal vertical axis (SVA) were 52.4°, 49.1°, 42.7°, and 315 mm, respectively. Pedicle subtraction osteotomy (PSO) at L3 was performed in the lateral position. The eggshell procedure was used during osteotomy. Case 2: a 45‐year‐old male AS patient presented coexisting rigid thoracolumbar kyphosis and hip flexion contracture. The range of movement of the hip was only about 20° in right and 25° in left. Pre‐operativeTK, TLK, LL and SVA were 34.9°, 66.8°, 58.8° and 290.8 mm, respectively. PSO at L₂ was performed in lateral position. The eggshell procedure was also used.

Results

Sagittal malalignments of both patients were greatly improved. For case 1, the total operation time was 5.5 h. The blood loss was 1500 mL and the amount of allogeneic blood transfusion was 1580 mL during the operation. SVA was reduced to 127 mm and LL decreased from preoperative 42.7° to −28.4°. The correction angle through L₃ was 34.7° and the correction angle through the osteotomy segment was 62.9°. For case 2, the duration of surgery was 6.5 h. The operative blood loss was 2000 mL and the total amount of blood transfusion was 2020 mL. SVA was reduced to 209.8 mm and LL decreased from preoperative 58.8° to 9.2°.The correction angle through L₂ was 37.1° and the correction angle through the osteotomy segment was 55°. No intra‐operative or post‐operative complications were observed. Six months after PSO, case 1 had good posture for standing and sitting. The case 2 underwent bilateral THRs nine months after PSO.

Conclusion

PSO could be performed in the lateral position successfully. For AS patients who cannot be placed in the prone position due to coexisting severe thoracolumbar kyphosis and hip flexion contracture, performing spinal osteotomy in the lateral position as the first step is an alternative.

Alignment, Classification, Clinical Evaluation, and Surgical Treatment for Adult Cervical Deformity: A Complete Guide

Adult cervical deformity management is complex and is a growing field with many recent advancements. The cervical spine functions to maintain the position of the head and plays a pivotal role in influencing subjacent global spinal alignment and pelvic tilt as compensatory changes occur to maintain horizontal gaze. There are various types of cervical deformity and a variety of surgical options available. The major advancements in the management of cervical deformity have only been around for a few years and continue to evolve. Therefore, the goal of this article is to provide a comprehensive review of cervical alignment parameters, deformity classification, clinical evaluation, and surgical treatment of adult cervical deformity. The information presented here may be used as a guide for proper preoperative evaluation and surgical treatment in the adult cervical deformity patient.

Flexing a standard hinge-powered operating table for lumbosacral three-column osteotomy (3-CO) site closure in 84 consecutive patients

Three-column osteotomy (3-CO) is a powerful technique in adult deformity surgery, and pedicle subtraction osteotomy (PSO) is the workhorse to correct severe kyphotic spinal deformities. Aging of the population, increasing cases of iatrogenic flat back deformities and understanding the importance of sagittal balance have led to a dramatic increase of this surgical technique. Surgery, however, is demanding and associated with high complication rates so that every step of the procedure requires meticulous technique. Particularly, osteotomy closure is associated with risks like secondary fracture, translation, or iatrogenic stenosis. This step is traditionally performed by compression or a cantilever maneuver with sometimes excessive forces on the screws or instrumentation. Implant loosening or abrupt subluxation resulting in construct failure and/or neurological deficits can result. The aim of this prospective registry study was to assess the efficacy and safety of our surgical PSO technique as well as the osteotomy closure by flexing a hinge-powered OR table. In a series of 84 consecutive lumbosacral 3-CO, a standardized surgical technique with special focus on closure of the osteotomy was prospectively evaluated. The surgical steps with the patients positioned prone on a soft frame are detailed. Osteotomy closure was achieved by remote controlled bending of a standard OR table without compressive or cantilever forces in all 84 cases. This technique carries a number of advantages, particularly the reversibility and the slow speed of closure with minimum force. There was not a single mechanical intraoperative complication such as vertebral body fracture, subluxation, or adjacent implant loosening during osteotomy closure, compared to external cohorts using the cantilever technique (p = 0.130). The feasibility of controlled 3-CO closure by flexing a standard OR table is demonstrated. This technique enables a safe, gentle closure of the osteotomy site with minimal risk of implant failure or accidental neurological injury.

State of the art review: Vertebral Osteotomies for the management of Spinal Deformity

Spinal deformity is a complex condition caused by various etiologies (degenerative, neuromuscular, congenital, developmental, traumatic, neoplastic, idiopathic) leading to clinical deformity, axial back pain, and neurologic deficits. Patients presenting with severe deformities require vertebral osteotomies to achieve the necessary curve correction for radiographic and clinical improvement. The three major vertebral osteotomy techniques commonly used at this time are the posterior column osteotomy (PCO), pedicle subtraction osteotomy (PSO), and vertebral column resection (VCR). The different vertebral osteotomies have unique merits and pitfalls that need to be addressed during preoperative planning to achieve maximum benefit while limiting or avoiding possible complications. The more difficult vertebral osteotomies have a steeper learning curve and requires extensive pre, intra and postoperative management of the patient. This review will aim to discuss the indications, surgical techniques, and clinical outcomes for each of these different vertebral osteotomy techniques with illustrative cases.

Modified mini-open SRS-Schwab grade 4 osteotomy combined with percutaneous pedicle screws fixation in post-traumatic thoracolumbar kyphosis

Background

We aimed to analyze the clinical results of Schwab grade 4 osteotomy combined with percutaneous pedicle screws (PPS) fixation for treatment of post-traumatic thoracolumbar kyphosis (PTK).

Methods

Thirty four patients with PTK (group A) were included in our study. The average age was 54.9 ± 3.3 years. All patients had severe back pain with 8.6 ± 1.3 VAS scores. The affected level was T12 in 16 patients and L1 in 18 patients. The average preoperative regional kyphosis angle (RKA) was 30.7 ± 6.00. Three patients had neurological dysfunction with ASIA grade D. All patients underwent Schwab grade 4 osteotomy combined with PPS fixation. The control group (Group B) were 26 PTK patients treated with Schwab grade 4 osteotomy and open pedicle screws fixation in our institution.

Results

Operation time in groups A and B was 280 ± 50 min and 210 ± 30 min, respectively (P < 0.05). Estimated blood loss in groups A and B was 310 ± 70 ml and 630 ± 40 ml, respectively (P < 0.05). No cerebral spinal fluid leakage, segmental nerve function damage, and other complications observed during and after the operations in both groups. RKA, SVA, and LL improved significantly after surgery in both groups (P < 0.05). The average correction rate in groups A and B was 64.5 and 66.3% (P > 0.05). CT showed that the misplacement rate in groups A and B was 5.5 and 6.6% (P > 0.05). The average follow-up in groups A and B was 25.2 ± 7.6 months and 30.6 ± 2.7 months. No fracture and other complications were observed in both groups. Solid bone fusion was showed in all cases at 6 months follow-up. In groups A and B, all patients with preoperative neurological dysfunction recovered to ASIA grade E at the last follow-up. The VAS score of back pain improved significantly from 8.6 ± 1.3 to 1.6 ± 1.0 at the last follow-up in group A (P < 0.05), while it improved significantly from 8.3 ± 1.2 to 3.0 ± 1.1 at the last follow-up in group B (P < 0.05). VAS of back pain was better in group A than that in group B.

Conclusion

Schwab grade 4 osteotomy combined with percutaneous pedicle screws fixation is a minimally invasive, safe and effective method for PTK treatment.

Modified C7 pedicle subtraction osteotomy for the correction of cervicothoracic kyphosis

BACKGROUND

Osteotomies in the cervical spine are technically challenging. The purpose of this study was to evaluate the feasibility of the modified pedicle subtraction osteotomy (PSO) technique at C7 to be used for the treatment of cervicothoracic kyphosis secondary to ankylosing spondylitis.

METHODS

A total of 120 cervical spine computed tomography (CT) scans (of 82 male and 38 female patients) were evaluated. The scans were taken parallel to the middle sagittal plane and the sagittal plane intersecting the pedicles. Simulated osteotomy was performed by setting the apex of the wedge osteotomy at different points, and morphologic measurements were obtained. Seven patients with cervicothoracic kyphosis who underwent a modified PSO at C7 between May 2009 and June 2015 were retrospectively evaluated. The mean follow up was 32.9 months (range 21-54 months). Preoperative and postoperative chin-brow vertical angle (CBVA), sagittal vertical axis (SVA) and sagittal Cobb angle of the cervical region were reviewed. The outcomes were analyzed through various measures, which included the 36-Item Short Form Health Survey (SF-36) and a visual analog scale for neck pain.

RESULTS

In this morphometric study, a modified PSO was performed on 87 patients (59 male and 28 female) with a reasonable ratio of 72.5%. In the case series, radiographic parameters and health-related quality-of-life measures were found to show significant postoperative improvement in all patients. No major complications occurred, and no implant failures were noted until the latest follow up.

CONCLUSIONS

The modified PSO is a safe and valid alternative to the classic PSO, allowing for excellent correction of cervical kyphosis and improvement in health-related quality-of-life measures.

The Effect of Tobacco Smoking on Adverse Events Following Adult Complex Deformity Surgery: Analysis of 270 Patients From the Prospective, Multicenter Scoli-RISK-1 Study

STUDY DESIGN

Post-hoc analysis of a prospective, multicenter cohort study.

OBJECTIVE

To analyze the impact of smoking on rates of postoperative adverse events (AEs) in patients undergoing high-risk adult spine deformity surgery.

SUMMARY OF BACKGROUND DATA

Smoking is a known predictor of medical complications after adult deformity surgery, but the effect on complications, implant failure and other AEs has not been adequately described in prospective studies.

METHODS

Twenty-six patients with a history of current smoking were identified out of the 272 patients enrolled in the SCOLI-RISK-1 study who underwent complex adult spinal deformity surgery at 15 centers, with 2-year follow-up. The outcomes and incidence of AEs in these patients were compared to the nonsmoking cohort (n = 244) using univariate analysis, with additional multivariate regression to adjust for the effect of patient demographics, complexity of surgery, and other confounders.

RESULTS

The number of levels and complexity of surgery in both cohorts were comparable. In the univariate analysis, the rates of implant failure were almost double (odds ratio 2.28 [0.75-6.18]) in smoking group (n = 7; 26.9%)) that observed in the nonsmoking group (n = 34; 13.9%), but this was not statistically significant (P = 0.088). Surgery-related excessive bleeding (>4 L) was significantly higher in the smoking group (n = 5 vs. n = 9; 19.2% vs. 3.7%; OR 6.22[1.48 - 22.75]; P = 0.006). Wound infection rates and respiratory complications were similar in both groups. In the multivariate analysis, the smoking group demonstrated a higher incidence of any surgery-related AEs over 2 years (n = 13 vs. n = 95; 50.0% vs. 38.9%; OR 2.12 [0.88-5.09]) (P = 0.094).

CONCLUSION

In this secondary analysis of patients from the SCOLI-RISK-1 study, a history of smoking significantly increased the risk of excessive intraoperative bleeding and nonsignificantly increased the rate of implant failure or surgery-related AEs over 2 years. The authors therefore advocate a smoking cessation program in patients undergoing complex adult spine deformity surgery.

LEVEL OF EVIDENCE

2.

Early Lumbar Nerve Root Deficit After Three Column Osteotomy for Fixed Sagittal Plane Deformities in Adults

Background

Three-column osteotomy is an effective means of correcting fixed sagittal plane deformities. Deformity correction surgeries may be associated with early postoperative neurological deficits often presenting as palsies involving the lumbar roots. The objective was to retrospectively assess a subset of our series of adult deformity correction surgeries and analyze neurological deficits and associated patient and surgical factors.

Methods

Hospital records of 17 patients from a single center were examined. Inclusion criterion were adults (>18 years) who underwent a 3-column osteotomy (pedicle subtraction osteotomy) at the lumbar level for fixed sagittal plane deformities including positive sagittal balance, flat back syndrome, and posttraumatic kyphosis. These also included cases with associated degenerative lumbar scoliosis. Patients were divided in 2 groups: Group 1 with lumbar root deficit and Group 2 with no deficits. We examined the surgical details of the osteotomy, complications during surgery, and observed if the magnitude of correction in the sagittal or coronal plane bore any influence on the nerve deficit.

Results

All 17 patients had a single-level resection except 1 patient who had 2-level osteotomy; 23.5% (4 of 17) developed nerve deficit. Nerve deficit presented as bilateral foot drop (1); unilateral extensor hallucis longus (EHL) weakness (2); and unilateral quadriceps weakness (1). The patient with quadriceps weakness partially recovered to functional strength. Two patients with EHL weakness fully recovered; however, the patient with bilateral foot drop did not improve. L5-S1 interbody fusion was done in 3 of 4 cases in Group 1 and 4 of 13 cases in Group 2.

Conclusions

Nerve deficits after 3-column corrective osteotomies occurred in 23% cases. All but 1 case had significant improvement. Most nerve palsies are neuropraxia and unilateral and tend to recover. L5 weakness appears most common after high lumbar osteotomies. Significant correction of scoliosis at the osteotomy level (>50%) may be a reason for nerve palsy.

Optimizing Pedicle Subtraction Osteotomy Techniques: A New Reduction Plier to Increase Technical Safety and Angular Reduction Efficiency

BACKGROUND

Pedicle subtraction osteotomy (PSO) is a technically demanding surgery. There is room for development of osteotomy reduction instruments like the one we present in this study, to better guide angular correction and closure of the osteotomy line.

OBJECTIVE

To present a new surgical instrument that optimizes PSOs of the thoracolumbar spine.

METHODS

Seventeen consecutive patients have been treated at 3 different European University Hospitals. All underwent a PSO of the lumbar spine to treat major sagittal imbalance. The amount of vertebral angular correction needed was calculated using the full balance integrated (FBI) method. A special plier, which allows to safely control the angular correction, was used intraoperatively. Preoperative and early postoperative global sagittal balance parameters were compared.

RESULTS

The mean preoperative calculated correction angle (FBI) was 33.8°; the mean postoperative correction obtained was 32.1°. Lumbar lordosis was statistically greater than preoperatively (55.8° vs 19.4°, P &lt; .0001). The global sagittal balance was improved, as shown by the increase of the spino-sacral angle from 122° preoperatively to 128° postoperatively (P = .0547). None of the patients had an intraoperative or early postoperative neurologic complication. There were no mechanical intraoperative complications during correction nor at the first postoperative follow-up.

CONCLUSION

The advantages of the instrument are safe, precise, and efficient reduction, by a rotation of the pedicle screws close to the osteotomy line, thus avoiding collapse and lack of correction, complications usually seen with the conventional technique. Further prospective studies are needed to confirm these results.

Lower Extremity Motor Function Following Complex Adult Spinal Deformity Surgery: Two-Year Follow-up in the Scoli-RISK-1 Prospective, Multicenter, International Study

BACKGROUND

The reported neurologic complication rate following surgery for complex adult spinal deformity (ASD) is variable due to several factors. Most series have been retrospective with heterogeneous patient populations and use of nonuniform neurologic assessments. The aim of this study was to prospectively document lower extremity motor function by means of the American Spinal Injury Association (ASIA) lower extremity motor score (LEMS) before and through 2 years after surgical correction of complex ASD.

METHODS

The Scoli-RISK-1 study enrolled 272 patients with ASD, from 15 centers, who had undergone primary or revision surgery for a major Cobb angle of ≥80°, corrective osteotomy for congenital spinal deformity or as a revision procedure for any type of deformity, and/or a complex 3-column osteotomy.

RESULTS

One of 272 patients lacked preoperative data and was excluded from the analysis, and 62 (22.9%) of the remaining 271 patients, who were included, lacked a 2-year postoperative assessment. Patients with no preoperative motor impairment (normal LEMS group; n = 203) had a small but significant decline from the mean preoperative LEMS value (50) to that at 2 years postoperatively (49.66 [95% confidence interval = 49.46 to 49.85]; p = 0.002). Patients who did have a motor deficit preoperatively (n = 68; mean LEMS, 43.79) had significant LEMS improvement at 6 months (47.21, p < 0.001) and 2 years (46.12, p = 0.003) postoperatively. The overall percentage of patients (in both groups combined) who had a postoperative LEMS decline, compared with the preoperative value, was 23.0% at discharge, 17.1% at 6 weeks, 9.9% at 6 months, and 10.0% at 2 years.

CONCLUSIONS

The percentage of patients who had a LEMS decline (compared with the preoperative score) after undergoing complex spinal reconstructive surgery for ASD was 23.0% at discharge, which improved to 10.0% at 2 years postoperatively. These rates are higher than previously reported, which we concluded was due to the prospective, strict nature of the LEMS testing of patients with these challenging deformities.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Pedicle Subtraction Osteotomy with a Cage Prevents Sagittal Translation in the Correction of Kyphosis in Ankylosing Spondylitis

BACKGROUND

Sagittal translation (ST) is an accidental event that surgeons commonly encounter during a spinal osteotomy in the correction of kyphosis in ankylosing spondylitis (AS). However, there is a paucity of effective techniques to prevent ST. The purpose of this study was to propose a pedicle subtraction osteotomy (PSO) with a cage as a method to prevent ST and to explore the efficacy and feasibility of this method in the treatment of kyphosis in AS.

METHODS

We retrospectively reviewed 89 consecutive patients with AS kyphosis who underwent a PSO (Group B, 46 patients) or a PSO with a cage (Group A, 43 patients) from February 2009 to December 2013. Pre- and post-operative radiographic results were reviewed. ST and complications were analyzed in both groups. Clinical assessment was performed using the Scoliosis Research Society-22 (SRS-22) outcomes metric. The patients were followed up for at least 2 years.

RESULTS

Group A achieved the same re-alignment of the kyphotic spine as Group B. Two (4.7%) of the 43 patients in Group A and 14 (30.4%) of the 46 patients in Group B had intraoperative ST (χ2 = 10.020, P = 0.002). Significant differences were identified between the two groups in the height change of the osteotomized column. SRS-22 scores improved significantly in both groups. Seven patients experienced neurologic complications (1 in Group A and 6 in Group B). Eight patients had cerebrospinal fluid leakage (2 in Group A and 6 in Group B).

CONCLUSION

PSO with a cage significantly avoided ST during the osteotomy procedure and might represent a new, safe, and feasible choice for treating patients with AS kyphosis.

Surgical and Radiographic Outcomes After Pedicle Subtraction Osteotomy According to Surgeon's Experience

STUDY DESIGN

Retrospective case series.

OBJECTIVE

The aim of this study was to evaluate and compare the surgical, radiographic, and clinical outcomes of pedicle subtraction osteotomy (PSO) according to surgeon's experience.

SUMMARY OF BACKGROUND DATA

Although PSO has been widely used to correct spinal deformities, it still remains technically demanding procedure with high complications.

METHODS

Comparative analysis of 40 consecutive patients treated with lumbar PSOs was performed. According to time period, the former and latter 20 patients were divided into group 1 and group 2, respectively. Patients' demographic data, operative, radiographic/clinical outcomes, and complications were compared between the groups.

RESULTS

Baseline characteristics and preoperative radiographic parameters were not different between the groups. Significant reductions of operative time (569.6 vs. 392.0 minutes, P = 0.000), surgical bleeding (1777.5 vs. 949.5 mL, P = 0.002), and transfused volume of red blood cell (1232.6 vs. 864.1 mL, P = 0.041) in group 2 were observed. Postoperative sagittal vertical axis was significantly different between the groups (40.1 and -3.6 mm, groups 1 and 2, respectively, P = 0.008), and the difference was sustained to the ultimate follow-up (59.4 vs. 13.2 mm, P = 0.003). There was a difference regarding the amount of curve correction by PSO, which was significantly greater in group 2 (25.7° vs. 35.8°, P = 0.023). Intraoperative complications (7 vs. 1, P = 0.019) were significantly lower in group 2. Total complications (20 vs. 10, P = 0.070), postoperative transient neurologic deficit (2 vs. 1), and revision surgery (4 vs. 3) were also lower in group 2, without statistical significance. The amount of the improvement of SRS-22 score was not different between the groups (P = 0.395).

CONCLUSION

PSO may be performed in patients with fixed sagittal imbalance with an acceptable rate of complications after about 20 cases. With acquisition of surgical experiences, surgeons could perform PSO more effectively and safely.

Vertebral column decancellation: a new spinal osteotomy technique for correcting rigid thoracolumbar kyphosis in patients with ankylosing spondylitis

AIMS

The aim of this study is to introduce and investigate the efficacy and feasibility of a new vertebral osteotomy technique, vertebral column decancellation (VCD), for rigid thoracolumbar kyphotic deformity (TLKD) secondary to ankylosing spondylitis (AS).

PATIENTS AND METHODS

We took 39 patients from between January 2009 and January 2013 (26 male, 13 female, mean age 37.4 years, 28 to 54) with AS and a TLKD who underwent VCD (VCD group) and compared their outcome with 45 patients (31 male, 14 female, mean age 34.8 years, 23 to 47) with AS and TLKD, who underwent pedicle subtraction osteotomy (PSO group), according to the same selection criteria. The technique of VCD was performed at single vertebral level in the thoracolumbar region of AS patients according to classification of AS kyphotic deformity. Pre- and post-operative chin-brow vertical angle (CBVA), sagittal vertical axis (SVA) and sagittal Cobb angle in the thoracolumbar region were reviewed in the VCD and PSO groups. Intra- , post-operative and general complications were analysed in both group.

RESULTS

lf patients could lie on their backs and walk with horizontal vision and sagittal profile, radiographic parameters improved significantly post-operatively in both groups. No major acute complications such as death or complete paralysis occurred in either group. In the VCD group, five patients (12.8%) experienced complications such as severe CSF leak (n = 4), deep wound infection (n = 1) and in one patient a transient neurological deficit occurred. In the PSO group, eight patients (17.8%) suffered conditions such as severe CSF leak (n = 5), infections (n = 2) and sagittal translation at osteotomy site (n = 1). Scoliosis Research Society outcomes instrument (SRS-22) improved significantly in both groups. All patients achieved solid fusion at latest follow-up and no implant failures were noted in either group.

TAKE HOME MESSAGE

The VCD technique is a new, safe and effective strategy for correction of rigid TLKD in AS patients. The main advantage of the new correction mechanism is that it achieved a satisfactory correction by controlled anterior column opening and posterior column closing, avoiding the occurrence of sagittal translation. Cite this article: Bone Joint J 2016;98-B:672-8.

Computer Simulation of Two-level Pedicle Subtraction Osteotomy for Severe Thoracolumbar Kyphosis in Ankylosing Spondylitis

BACKGROUND

Advanced ankylosing spondylitis is often associated with thoracolumbar kyphosis, resulting in an abnormal spinopelvic balance and pelvic morphology. Different osteotomy techniques have been used to correct AS deformities, unfortunnaly, not all AS patients can gain spinal sagittal balance and good horizontal vision after osteotomy.

MATERIALS AND METHODS

Fourteen consecutive AS patients with severe thoracolumbar kyphosis who were treated with two-level PSO were studied retrospectively. All were male with a mean age of 34.9 ± 9.6 years. The followup ranged from 1-5 years. Preoperative computer simulations using the Surgimap Spinal software were performed for all patients, and the osteotomy level and angle determined from the computer simulation were used surgically. Spinal sagittal parameters were measured preoperatively, after the computer simulation, and postoperatively and included thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence, pelvic tilt (PT), and sacral slope (SS). The level of correlation between the computer simulation and postoperative parameters was evaluated, and the differences between preoperative and postoperative parameters were compared. The visual analog scale (VAS) for back pain and clinical outcome was also assessed.

RESULTS

Six cases underwent PSO at L1 and L3, five cases at L2 and T12, and three cases at L3 and T12. TK was corrected from 57.8 ± 15.2° preoperatively to 45.3 ± 7.7° postoperatively (P < 0.05), LL from 9.3 ± 17.5° to -52.3 ± 3.9° (P < 0.001), SVA from 154.5 ± 36.7 to 37.8 ± 8.4 mm (P < 0.001), PT from 43.3 ± 6.1° to 18.0 ± 0.9° (P < 0.001), and SS from 0.8 ± 7.0° to 26.5 ± 10.6° (P < 0.001). The LL, VAS, and PT of the simulated two-level PSO were highly consistent with, or almost the same as, the postoperative parameters. The correlations between the computer simulations and postoperative parameters were significant. The VAS decreased significantly from 6.1 ± 1.9 to 2.0 ± 1.1 (P < 0.001). In terms of clinical outcome, 10 cases were graded "excellent" and 4 cases were graded "good."

CONCLUSION

Two-level PSO using a preoperative computer simulation is a feasible, safe, and effective technique for the treatment of severe thoracolumbar kyphosis in AS patients with normal cervical motion.

Y Shape Osteotomy in Ankylosing Spondylitis, a Prospective Case Series with Minimum 2 Year Follow-Up

The aim of the study is to evaluate the efficacy of a spinal osteotomy technique, Y shape osteotomy, for correcting kyphosis in AS patients planned preoperatively with computer software-assistance. 36 consecutive AS patients with thoracolumbar kyphosis were treated with one-stage posterior Y shape osteotomy and preoperative surgical planning was done with the aid of the Surgimap Spine. Radiological parameters of simulation and immediate postoperation were documented. Clinical and radiological results were evaluated in the preoperative, the early postoperative periods and during the last follow-up. The lumbar lordosis was found as 40.7 ± 4.1 degrees in the surgical planning and 49.7 ± 3.9 degrees postoperatively (p<0.01). PI-LL was 3.8± 0.9°in the simulation procedure and 6.6± 1.5°postoperatively (p<0.01). At the final follow-up, Global sagittal balance was restored and Both Oswestry Disability Index and Scoliosis Research Society scores improved largely. In conclusion, Y shape osteotomy is a safe and effective treatment option for AS patients with kyphosis deformity.

Modified eggshell procedure via posterior approach for sclerosing thoracic disc herniation: a preliminary study

BACKGROUND

Clinically, sclerosing thoracic disc herniation is a disease with high surgical risk and various complications. Eggshell procedure is a surgical method used by surgeons to treat sclerosing thoracic disc herniation. The aim of this study was to report a modified eggshell procedure to treat sclerosing thoracic disc herniation.

METHODS

Medical records of 25 patients with sclerosing thoracic disc herniation were collected between 2007/01 and 2010/08, including 14 males and 11 females, with an average age of 51.7 years old. Modified eggshell procedure was performed to treat the patients with sclerosing thoracic disc herniation. All patients were followed up. Japanese Orthopaedic Association (JOA) score was used to evaluate the clinical outcomes.

RESULTS

All operations were performed successfully with complication rate of 12 %. There were 2 cases of dural laceration and 1 subdural hematoma. All included patients were followed up for at least 5 years, with the median of 6 years. JOA score of preoperation was 5 (IQR = 1) while it was 8 (IQR = 2) at final follow-up, with significant difference (Mann-Whitney U test, Z = -4.891, P < 0.001). The improvement rate of neurological status was 51.5 ± 23.1 %. According to the classification of improvement rate, there were 15 cases at good level, 8 cases at moderate level, and 2 cases without any improvement.

CONCLUSIONS

Modified eggshell procedure is a safe and effective surgical method when performed to treat sclerosing thoracic disc herniation in the clinical practice.

One-stage posterior focus debridement, interbody grafts, and posterior instrumentation and fusion in the surgical treatment of thoracolumbar spinal tuberculosis with kyphosis in children: a preliminary report

PURPOSE

The purpose of this study was to determine the efficacy and feasibility of surgical management of children with thoracolumbar spine tuberculosis with kyphosis by using one-stage posterior focus debridement, interbody grafts, and posterior instrumentation and fusion.

METHODS

From October 2010 to September 2013, 21 children with thoracolumbar spinal tuberculosis accompanied by kyphosis were treated with one-stage posterior decompression, interbody grafts, and posterior instrumentation and fusion. There were 13 males and 8 females, aged from 7 to 13 years old (average age 9.9 years). The mean follow-up was 34 months (range26-48 months). Patients were evaluated before and after surgery in terms of ESR, neurologic status, pain, and kyphotic angle.

RESULTS

Spinal tuberculosis was completely cured, and the grafted bones were fused in all 21 patients. There was no recurrent tuberculous infection. ESR got normal within 3 months in all patients. The ASIA neurologic classification improved in all cases. Pain relief was obtained in all patients. The average preoperative kyphosis was 29.7° (range 12-42°) and decreased to 5.5° (range 2-10°), postoperatively. There was no significant loss of the correction at the latest follow-up.

CONCLUSIONS

Our results show that one-stage posterior decompression, interbody grafts, and posterior instrumentation and fusion were an effective treatment for children with thoracolumbar spinal tuberculosis. It is characterized as minimum surgical trauma, good neurologic recovery, good correction of kyphosis, and prevention of progressive kyphosis.

Spinal cord stimulation for recurrent tethered cord syndrome in a pediatric patient: case report

The authors present a patient with a lipomyelomeningocele and worsening back pain due to recurrent tethered cord syndrome. Because of the increased risk and unlikely improvement in symptoms with repeated surgical untethering, she was offered an alternative treatment with a trial of dorsal spinal cord stimulation. She had an excellent response to the percutaneous trial, and a permanent implant was placed, with good initial results. The authors review her case as well as the treatment options, indications, and outcomes for recurrent tethered cord syndrome.

Neurologic Outcomes of Complex Adult Spinal Deformity Surgery: Results of the Prospective, Multicenter Scoli-RISK-1 Study

STUDY DESIGN

Prospective, multicenter, international observational study.

OBJECTIVE

To evaluate motor neurologic outcomes in patients undergoing surgery for complex adult spinal deformity (ASD).

SUMMARY OF BACKGROUND DATA

The neurologic outcomes after surgical correction for ASD have been reported with significant variability and have not been measured as a primary endpoint in any prospective, multicenter, observational study.

METHODS

The primary outcome measure was the change in American Spinal Injury Association (ASIA) Lower Extremity Motor Scores (LEMS) obtained preoperatively, and at hospital discharge, 6 weeks and 6 months postoperatively.

RESULTS

A total of 273 patients with complex ASD underwent surgery at 15 sites worldwide. One patient was excluded for lack of preoperative LEMS. The remaining 272 patients were divided into two groups: normal preoperative LEMS (=50) (Preop NML, N = 204, 75%) and abnormal preoperative LEMS (<50) (Preop ABNML, N = 68, 25%). At hospital discharge, 22.18% of patients showed a decline in LEMS compared with 12.78% who showed an improvement. At 6 weeks, there was a significant change compared with discharge: 17.91% patients showed a decline in LEMS and 16.42% showed an improvement. At 6 months, 10.82% patients showed a decline in preoperative LEMS, 20.52% improvement, and 68.66% maintenance. This was a significant change compared with 6 weeks and at discharge.

CONCLUSION

Although complex ASD surgery can restore neurologic function in patients with a preoperative neurologic deficit, a significant portion of patients with ASD experienced postoperative decline in LEMS. Measures that can anticipate and reduce the risk of postoperative neurologic complications are warranted.

LEVEL OF EVIDENCE

3.

Comparison of Clinical and Radiological Improvement Between the Modified Trephine and High-speed Drill as Main Osteotomy Instrument in Pedicle Subtraction Osteotomy

High-speed drill is the main osteotomy instrument in pedicle subtraction osteotomy (PSO) currently. Considering the long duration of surgery, the large amount of blood loss, and the high incidence of neurovascular injury, the osteotomy procedure is challenging. Use of trephine for the osteotomy displays high efficiency by shortening surgery time and reducing blood loss in anterior cervical corpectomy and fusion. However, the potential risk of neurological injury is high. We modified the trephine by adding locking instrument, when the serrated top of the trephine reaches the tip of the probe; the locking instrument on the probe restricts the trephine and improves security during the osteotomy procedure.The aim of this study was to compare the clinical and radiological improvement between the modified trephine and high-speed drill as main osteotomy instrument in PSO.From February 2009 to 2013, 50 patients with severe thoracolumbar kyphotic deformity caused by old compressive vertebrae were prospectively reviewed. All patients were randomly assigned to the experimental group (27 patients received PSO with modified trephine) and the control group (23 patients received PSO with high-speed drill). The clinical records were reviewed and compared for surgical time, operative blood loss, functional improvement (Oswestry Disability Index), and pain relief (visual analog scale). The radiological records were reviewed and compared for correction of kyphotic deformity postoperatively and correction loss at 2-year follow-up.All patients successfully finished the PSO procedure, and got satisfactory kyphotic deformity correction and overall function improvement. The surgery time was shorter in the experimental group than that in the control group (132.7 ± 12.6 vs 141.7 ± 16.7 min; P = 0.03). No significant difference was found in blood loss (882.9 ± 98.9 mL vs 902.2 ± 84.9 mL; P = 0.47) or correction of the kyphotic angle (33.4 ± 3.4° vs 32.1 ± 2.5°, P = 0.13) postoperatively between the 2 groups. At 24-month follow-up, no difference was discovered in loss of the correction (4.9 ± 1.6° vs 4.5 ± 1.6°; P = 0.42), change of Oswestry Disability Index (49.4 ± 6.2% vs 48.2 ± 4.2%; P = 0.44), or in back pain relief (6.2 ± 1.4 vs 6.4 ± 1.2 min; P = 0.51) between the 2 groups. No internal fixation related complication occurred and bony fusion was detected in lateral X-ray in all patients. In the control group, 2 patients had transient nerve root deficit, 14 patients at 3-month follow-up and 3 patients at 2-year follow-up experienced graft donor site morbidity, and pain killer medicine was always required.In conclusion, the modified trephine obviously shortens surgery time, and prevents graft donor site morbidity when compared to a high-speed drill. The learning curve for using the modified trephine in PSO procedure is short.

The likelihood of reaching minimum clinically important difference and substantial clinical benefit at 2 years following a 3-column osteotomy: analysis of 140 patients

OBJECT

Three-column osteotomies (3COs) are technically challenging techniques for correcting severe rigid spinal deformities. The impact of these interventions on outcomes reaching minimum clinically important difference (MCID) or substantial clinical benefit (SCB) is unclear. The objective of this study was to determine the rates of MCID and SCB in standard health-related quality of life (HRQOL) measures after 3COs in patients with adult spinal deformity (ASD). The impacts of location of the uppermost instrumented vertebra (UIV) on clinical outcomes and of maintenance on sagittal correction at 2 years postoperatively were also examined.

METHODS

The authors conducted a retrospective multicenter analysis of the records from adult patients who underwent 3CO with complete 2-year radiographic and clinical follow-ups. Cases were categorized according to established radiographic thresholds for pelvic tilt (> 22°), sagittal vertical axis (> 4.7 cm), and the mismatch between pelvic incidence and lumbar lordosis (> 11°). The cases were also analyzed on the basis of a UIV in the upper thoracic (T1–6) or thoracolumbar (T9–L1) region. Patient-reported outcome measures evaluated preoperatively and 2 years postoperatively included Oswestry Disability Index (ODI) scores, the Physical Component Summary and Mental Component Summary (MCS) scores of the 36-Item Short Form Health Survey, and Scoliosis Research Society-22 questionnaire (SRS-22) scores. The percentages of patients whose outcomes for these measures met MCID and SCB were compared among the groups.

RESULTS

Data from 140 patients (101 women and 39 men) were included in the analysis; the average patient age was 57.3 ± 12.4 years (range 20–82 years). Of these patients, 94 had undergone only pedicle subtraction osteotomy (PSO) and 42 only vertebral column resection (VCR); 113 patients had a UIV in the upper thoracic (n = 63) orthoracolumbar region (n = 50). On average, 2 years postoperatively the patients had significantly improved in all HRQOL measures except the MCS score. For the entire patient cohort, the improvements ranged from 57.6% for the SRS-22 pain score MCID to 24.4% for the ODI score SCB. For patients undergoing PSO or VCR, the likelihood of their outcomes reaching MCID or SCB ranged from 24.3% to 62.3% and from 16.2% to 47.8%, respectively. The SRS-22 self-image score of patients who had a UIV in the upper thoracic region reached MCID significantly more than that of patients who had a UIV in the thoracolumbar region (70.6% vs 41.9%, p = 0.0281). All other outcomes were similar for UIVs of upper thoracic and thoracolumbar regions. Comparison of patients whose spines were above or below the radiographic thresholds associated with disability indicated similar rates of meeting MCID and SCB for HRQOL at the 2-year follow-up.

CONCLUSIONS

Outcomes for patients having UIVs in the upper thoracic region were no more likely to meet MCID or SCB than for those having UIVs in the thoracolumbar region, except for the MCID in the SRS-22 self-image measure. The HRQOL outcomes in patients who had optimal sagittal correction according to radiographic thresholds determined preoperatively were not significantly more likely to reach MCID or SCB at the 2-year follow-up. Future work needs to determine whether the Schwab preoperative radiographic thresholds for severe disability apply in postoperative settings.

Transforaminal Anterior Release for the Treatment of Fixed Sagittal Imbalance and Segmental Kyphosis, Minimum 2-Year Follow-Up Study

STUDY DESIGN

Retrospective review of prospectively accrued patient cohort.

OBJECTIVE

To report minimum 2 years' follow-up after a single-surgeon series of 47 consecutive patients in whom fixed sagittal imbalance or segmental kyphosis was treated with a novel unilateral transforaminal annular release.

SUMMARY OF BACKGROUND DATA

Fixed sagittal imbalance has been treated most recently with pedicle subtraction osteotomy with great success but is associated with significant blood loss and neurologic risk.

METHOD

Forty-seven consecutive patients with fixed sagittal imbalance (n = 29) or segmental kyphosis (n = 18) were treated by a single surgeon with a single-level transforaminal anterior release (TFAR) to effect an opening wedge correction. Sagittal and coronal correction was performed with in situ rod contouring. An interbody cage was captured in the disc space with rod compression. Radiographic and clinical outcome analysis was performed with a minimum 2-year follow-up (range 2-7.8 years).

RESULTS

The average increase in lordosis was 36° (range 24°-56°) in the fixed sagittal deformity group. Coronal corrections averaged 34° (range 18°-48°). The average improvement in plumb line was 13.6 cm. There were four pseudarthroses, one at the TFAR. Average blood loss was 578 mL (range 200-1,200). One patient had a transient grade 4/5 anterior tibialis weakness. There were no vascular injuries or permanent neurologic deficits. There were significant improvements in the Oswestry Disability Index (p < .001) and Scoliosis Research Society Questionnaire scores (p = .003). Eighty-four percent of patients reported improvement in pain, self-image, and satisfaction with the procedure.

CONCLUSION

TFAR is a useful procedure for correcting segmental kyphosis and fixed sagittal imbalance with relatively low blood loss and was found to be neurologically safe in this single-surgeon series.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series, no control group).

Lung volume change after pedicle subtraction osteotomy in patients with ankylosing spondylitis with thoracolumbar kyphosis

STUDY DESIGN

A retrospective clinical study.

OBJECTIVE

To investigate the lung volume (LV) change in patients with ankylosing spondylitis (AS) with thoracolumbar kyphosis after the pedicle subtraction osteotomy procedure.

SUMMARY OF BACKGROUND DATA

Thoracolumbar kyphosis with respiratory impairment is the consequence of most untreated AS patients. Restrictive pulmonary function is prevalent in these patients. The ideal evidence for restrictive pulmonary function impairment is to investigate the LV. A computed tomography (CT)-based method can help to obtain accurate LV change during the osteotomy.

METHOD

Twenty-eight patients with AS with thoracolumbar kyphosis were included. All of these patients underwent pedicle subtraction osteotomy to correct their sagittal deformity. Pre- and postoperative full-length radiographs and CT scans were reviewed. The sagittal correction of the spine was measured. CT scans were used to estimate the pre- and postoperative LV with software. The relationship between the sagittal correction and the LV change was investigated. All the patients were followed up for 2 years at least.

RESULTS

The pedicle subtraction osteotomy procedure was performed safely on each patient without serious complications. The average preoperative T1-S1 Cobb was 67.7° (42°∼88°) and the postoperative was 7.6° (-11°∼21°). T1-S1 Cobb change was 60.0° in average (P < 0.05). The LV increased by 396 mL in average. Significant correlation was found between the percentage of LV change and T1-S1 Cobb change (r = 0.7219, P < 0.05). The location we selected for pedicle subtraction osteotomy varied from T12 to L3. No relationship was found between the osteotomy location and the LV change.

CONCLUSION

The pedicle subtraction osteotomy effectively corrected the sagittal deformity of patients with AS. LV increased significantly after the osteotomy.

LEVEL OF EVIDENCE

4.

Minimally invasive spine surgery for adult degenerative lumbar scoliosis

OBJECT

Historically, adult degenerative lumbar scoliosis (DLS) has been treated with multilevel decompression and instrumented fusion to reduce neural compression and stabilize the spinal column. However, due to the profound morbidity associated with complex multilevel surgery, particularly in elderly patients and those with multiple medical comorbidities, minimally invasive surgical approaches have been proposed. The goal of this meta-analysis was to review the differences in patient selection for minimally invasive surgical versus open surgical procedures for adult DLS, and to compare the postoperative outcomes following minimally invasive surgery (MIS) and open surgery.

METHODS

In this meta-analysis the authors analyzed the complication rates and the clinical outcomes for patients with adult DLS undergoing complex decompressive procedures with fusion versus minimally invasive surgical approaches. Minimally invasive surgical approaches included decompressive laminectomy, microscopic decompression, lateral and extreme lateral interbody fusion (XLIF), and percutaneous pedicle screw placement for fusion. Mean patient age, complication rates, reoperation rates, Cobb angle, and measures of sagittal balance were investigated and compared between groups.

RESULTS

Twelve studies were identified for comparison in the MIS group, with 8 studies describing the lateral interbody fusion or XLIF and 4 studies describing decompression without fusion. In the decompression MIS group, the mean preoperative Cobb angle was 16.7° and mean postoperative Cobb angle was 18°. In the XLIF group, mean pre- and postoperative Cobb angles were 22.3° and 9.2°, respectively. The difference in postoperative Cobb angle was statistically significant between groups on 1-way ANOVA (p = 0.014). Mean preoperative Cobb angle, mean patient age, and complication rate did not differ between the XLIF and decompression groups. Thirty-five studies were identified for inclusion in the open surgery group, with 18 studies describing patients with open fusion without osteotomy and 17 papers detailing outcomes after open fusion with osteotomy. Mean preoperative curve in the open fusion without osteotomy and with osteotomy groups was 41.3° and 32°, respectively. Mean reoperation rate was significantly higher in the osteotomy group (p = 0.008). On 1-way ANOVA comparing all groups, there was a statistically significant difference in mean age (p = 0.004) and mean preoperative curve (p = 0.002). There was no statistically significant difference in complication rates between groups (p = 0.28).

CONCLUSIONS

The results of this study suggest that surgeons are offering patients open surgery or MIS depending on their age and the severity of their deformity. Greater sagittal and coronal correction was noted in the XLIF versus decompression only MIS groups. Larger Cobb angles, greater sagittal imbalance, and higher reoperation rates were found in studies reporting the use of open fusion with osteotomy. Although complication rates did not significantly differ between groups, these data are difficult to interpret given the heterogeneity in reporting complications between studies.

Insufficient restoration of lumbar lordosis and FBI index following pedicle subtraction osteotomy is an indicator of likely mechanical complication

PURPOSE

Pedicle subtraction osteotomies (PSO) enable correction of spinal deformities but remain difficult and are associated with high complication rates. This study aimed to prospectively review different post-operative complications and mechanical problems in patients who underwent PSO as treatment for sagittal imbalance as sequelae of degenerative disc disease or previous spinal fusion.

METHOD

This was a descriptive prospective single center study of 63 patients who underwent sagittal imbalance correction by PSO. Radiographic analysis of pre- and post-operative pelvic and spinal parameters was completed based on EOS images following 3D modeling. Global and sub-group analyses were completed based on the Roussouly classification. A systematic analysis of post-operative complications was conducted during hospital stay and at follow-up visits.

RESULTS

Complications included 15 cases (20.2%) of bilateral leg pain, with transient neurological deficit in 6 cases (9.5%), and 9 cases (12.5%) of early surgical site infections. Intra-operative complications included five tears of the dura mater and two cases of excessive blood loss (>5,000 mL). Two mortalities occurred from major intracerebral bleeds in the early post-operative period. Mechanical complications were principally non-union (9 cases) and junctional kyphosis (3 cases). All 19 post-operative complications (28.1%) were revised at an average of 2 years following surgery. All mechanical complications were found in the patients who had insufficient imbalance correction and this was mainly associated with high PI (>60°) or a moderate PI (45-60º) combined with excess FBI pre-operatively that remained >10° post-operatively.

CONCLUSION

Infection and neurologic complications following PSO are relatively common, and frequently reported in the literature. The principal cause of mechanical complications, such as non-union or junctional kyphosis, was insufficient sagittal correction, characterized by post-operative FBI >10°. The risks of insufficient correction are greater in patients with higher pelvic incidence and those patients who required very high correction.

Preoperative computer-based simulations for the correction of kyphotic deformities in ankylosing spondylitis patients

BACKGROUND CONTEXT

A preoperative plan is important to obtain appropriate balance of the sagittal plane in patients with kyphotic deformity. Previous methods to calculate the correction angle are inconvenient and complicated, whereas the method using computer simulations may be very effective and much simpler than existing methods.

PURPOSE

To evaluate the efficacy of preoperative measurements using a computer simulation for corrective osteotomy for the surgical treatment of kyphosis caused by ankylosing spondylitis (AS).

STUDY DESIGN

Retrospective clinical data analysis.

PATIENT SAMPLE

The sample comprises 18 AS patients with fixed kyphotic deformity who underwent corrective osteotomies at our hospital between October 2007 and January 2010.

OUTCOME MEASURES

Thoracic kyphosis, lumbar lordosis, and the sagittal vertical axis (SVA) of the spine were evaluated by preoperative computer simulation and radiologic measurement. Clinical assessments were performed according to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Short Form-36 (SF-36), and EuroQol-5 dimension (EQ-5D) before and after the surgery.

METHODS

The coincidence between the preoperative computer simulation and postoperative radiologic parameters was evaluated. We also analyzed the changes derived from each clinical and radiologic measurement before and after the surgery.

RESULTS

Mean thoracic kyphosis changed from 32.4° to 31.9°, mean lumbar lordosis was corrected from 11.5° to 26.9°, and the SVA was improved from 125.7 to 65.1 mm after surgery (p<.001). The correlation coefficients within groups between the computer simulations and radiologic parameters were 0.9, 0.6, and 0.7, showing significant congruency. Although BASDAI and BASFI did not significantly differ (p=.53 and p=.45, respectively), SF-36 and EQ-5D were significantly increased (p<.05 and p<.001, respectively).

CONCLUSIONS

Comparisons of preoperative simulations and actual surgical outcomes showed significant coincidences; thus, evaluations through computer simulations before surgery are expected to help predict the level of correction possible after surgery and improve surgical planning.

Spinal osteotomy in ankylosing spondylitis: radiological, clinical, and psychological results

BACKGROUND CONTEXT

Little is known about the psychological status in patients with ankylosing spondylitis (AS) before and after correction of fixed sagittal imbalance.

PURPOSE

The aim of this study was to evaluate the changes in patients' psychological status after surgical correction and the existence of a correlation between psychological state and the angle of correction.

STUDY DESIGN

A retrospective study was performed to assess radiological and clinical results, and psychological status in patients with AS with fixed kyphotic deformity.

PATIENT SAMPLE

The sample comprises 24 patients with AS with fixed sagittal imbalance who underwent one-stage corrective osteotomies at our hospital between March 2006 and May 2010. All of the patients included in this study demonstrated an inability to look straight forward because of severe kyphotic deformities.

OUTCOME MEASURE

The radiologic analysis included evaluation of thoracic kyphosis, lumbar lordosis, and the sagittal vertical axis (SVA) of the spine. Clinical assessments were performed with Short Form 36 (SF-36), the Bath Ankylosing Spondylitis Function Index (BASFI), and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Patient psychological status was assessed using the Hospital Anxiety and Depression Questionnaire (HADS) and the Health Locus of Control-Form C Questionnaire (HLC-C).

METHODS

Each of the above measurements was recorded before and 1 year after the surgery. The changes derived from each measurement before and after the surgery were evaluated. We also analyze the correlations among the radiological, clinical, psychological, and mental evaluations.

RESULTS

Mean thoracic kyphosis changed from 38.5° to 33.3°. Mean lumbar lordosis was corrected from 13.8° to 26.1°, and the SVA was improved from 110.8 mm to 49.7 mm. There was significant improvement in the SF-36, BASDAI, BASFI, HADS, and HLC-C scores. The SVA changes were closely linked to BASFI and psychological status, especially anxiety and depression.

CONCLUSIONS

The scores of disease status, general health, and psychological status were improved significantly after correction of kyphotic deformity. And the correction of sagittal imbalance was correlated significantly with anxiety and depression.

Risk factors for and assessment of symptomatic pseudarthrosis after lumbar pedicle subtraction osteotomy in adult spinal deformity

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To assess the prevalence, risk factors, and clinical outcomes for pseudarthrosis after a lumbar pedicle subtraction osteotomy (PSO).

SUMMARY OF BACKGROUND DATA

There exists no large series that examines pseudarthrosis rates of PSOs.

METHODS

Data of 171 consecutive patients with adult deformity who underwent a lumbar PSO by 2 surgeons at a single institution with a minimum 2-year follow-up were analyzed. Pseudarthrosis diagnosed through sagittal malalignment and instrumentation failure noted on radiograph was confirmed intraoperatively.

RESULTS

Eighteen (10.5%) of 171 patients developed pseudarthrosis after a PSO. Eleven of the 18 patients (6.4% of all patients, 61.1% of the 18 patients with pseudarthrosis) had pseudarthrosis at the PSO site, L3 being the most common; other locations included the lumbosacral junction (4/18), thoracolumbar junction (2/18), and upper thoracic spine (1/18). Preoperative pseudarthrosis level was a predictor of the postoperative level of pseudarthrosis (93%). Fifteen of the 18 patients (83%) had no interbody fusion directly above or below the PSO site, 16 (88%) had a history of pseudarthrosis at the time of PSO surgery and 2 of 3 patients who had prior radiation to the lumbar region developed pseudarthrosis. Most pseudarthroses occurred within the first 2 years (n = 13/18), between 2 and 5 years (n = 3/18), and more than 5 years (n = 2/18) postoperatively. Prior pseudarthrosis (P < 0.0001), pseudarthrosis at the PSO site (P < 0.0001), prior decompression in the lumbar region (P = 0.0037), prior radiation to the lumbar region (P < 0.0001), and presence of inflammatory/neurological disorders (P < 0.0036) were identified as risk factors. All 18 patients with pseudarthroses required revision surgery (posterior-only surgery, n = 12; anteroposterior surgery, n = 6) due to loss of sagittal alignment and pain. The mean pre-revision Scoliosis Research Society score was 85, post-revision score was 95 (P = 0.0166), and the mean pre-revision Oswestry Disability Index score was 42.5, post-revision score was 34.5 (P = 0.0203).

CONCLUSION

The overall prevalence of pseudarthrosis was 10.5% of which 61% occurred at the actual PSO site and Scoliosis Research Society and Oswestry Disability Index scores improved significantly after pseudarthrosis repair.

LEVEL OF EVIDENCE

4.

Maintenance of radiographic correction at 2 years following lumbar pedicle subtraction osteotomy is superior with upper thoracic compared with thoracolumbar junction upper instrumented vertebra

PURPOSE

The goal of this study was to characterize the spino-pelvic realignment and the maintenance of that realignment by the upper-most instrumented vertebra (UIV) for adult deformity spinal (ASD) patients treated with lumbar pedicle subtraction osteotomy (PSO).

METHODS

ASD patients were divided by UIV, classified as upper thoracic (UT: T1-T6) or Thoracolumbar (TL: T9-L1). Complications were recorded and radiographic parameters included thoracic kyphosis (TK, T2-T12), lumbar lordosis (LL, L1-S1), sagittal vertical axis (SVA), pelvic tilt, and the mismatch between pelvic incidence and LL. Patients were also classified by the Scoliosis Research Society (SRS)-Schwab modifier grades. Changes in radiographic parameters and SRS-Schwab grades were evaluated between the two groups. Additional analyses were performed on patients with pre-operative SVA ≥ 15 cm.

RESULTS

165 patients were included (UT: 81 and TL: 84); 124 women, 41 men, with average age 59.9 ± 11.1 years (range 25-81). UT had a lower percentage of patients above the radiographic thresholds for disability than TL. UT had a significantly higher percentage of patients that improved in SRS-Schwab global alignment grade than the TL group at 2 years. Within the patients with pre-operative SVA ≥ 15 cm, TL developed significantly increased SVA and had a significantly higher percentage of patients above the SVA threshold at 3 months, and 1 and 2 years than UT.

CONCLUSIONS

Patients undergoing a single-level PSO for ASD who have fixation extending to the UT region (T1-T6) are more likely to maintain sagittal spino-pelvic alignment, lower overall revision rates and revision rate for proximal junctional kyphosis than those with fixation terminating in the TL region (T9-L1).

Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The long-term overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided.

Pedicle subtraction osteotomy in elderly patients with degenerative sagittal imbalance

STUDY DESIGN

Retrospective, radiographical analysis.

OBJECTIVE

To evaluate pedicle subtraction osteotomy (PSO) as a means of correcting severe degenerative sagittal imbalance in elderly patients.

SUMMARY OF BACKGROUND DATA

PSO in patients with degenerative sagittal imbalance is likely to cause more complications than in patients with iatrogenic flatback deformity.

METHODS

This study analyzed 34 patients who underwent fusion to the sacrum, with a minimum 2-year follow-up. Age of the patients were in the range from 58 to 73 with the mean at 65.5 years. PSO was performed at one segment in all cases, consisting of L3 (n = 26), L4 (n = 4), L2 (n = 3), and L1 (n = 1). The average number of levels fused was 8.15. Ten patients had structural interbody fusion at the lumbosacral junction.

RESULTS

Applying PSO at one segment, the mean correction of the lordotic angle at the osteotomy site was 33.3°, of which the loss of correction (LOC) was 4.0° at the last visit. The correction of lumbar lordosis was 33.7° and the LOC was 8.5°. The sagittal C7 plumb was 215.9 mm before surgery, corrected to 35.1 mm after surgery, and changed to 95.9 mm by the last visit. The correction of the sagittal C7 plumb was 119.9 mm and the LOC was 60.9 mm. There was substantial LOC in lumbar lordosis and sagittal C7 plumb. In 10 patients with addition of posterior lumbar interbody fusion, the LOC of lumbar lordosis was 7.4°, which was less than 9° in those without it.

CONCLUSION

PSO for the correction of degenerative sagittal imbalance in elderly patients resulted in correction of sagittal alignment with a significant LOC of lumbar lordosis and sagittal C7 plumb. The LOC of lumbar lordosis occurred at both the osteotomy and non-osteotomy site. The addition of anterior column support is helpful to maintain correction and reduce complications.

LEVEL OF EVIDENCE

N/A.

A standardized nomenclature for cervical spine soft-tissue release and osteotomy for deformity correction

Object

Cervical spine osteotomies are powerful techniques to correct rigid cervical spine deformity. Many variations exist, however, and there is no current standardized system with which to describe and classify cervical osteotomies. This complicates the ability to compare outcomes across procedures and studies. The authors' objective was to establish a universal nomenclature for cervical spine osteotomies to provide a common language among spine surgeons.

Methods

A proposed nomenclature with 7 anatomical grades of increasing extent of bone/soft tissue resection and destabilization was designed. The highest grade of resection is termed the major osteotomy, and an approach modifier is used to denote the surgical approach(es), including anterior (A), posterior (P), anterior-posterior (AP), posterior-anterior (PA), anterior-posterior-anterior (APA), and posterior-anterior-posterior (PAP). For cases in which multiple grades of osteotomies were performed, the highest grade is termed the major osteotomy, and lower-grade osteotomies are termed minor osteotomies. The nomenclature was evaluated by 11 reviewers through 25 different radiographic clinical cases. The review was performed twice, separated by a minimum 1-week interval. Reliability was assessed using Fleiss kappa coefficients.

Results

The average intrarater reliability was classified as “almost perfect agreement” for the major osteotomy (0.89 [range 0.60–1.00]) and approach modifier (0.99 [0.95–1.00]); it was classified as “moderate agreement” for the minor osteotomy (0.73 [range 0.41–1.00]). The average interrater reliability for the 2 readings was the following: major osteotomy, 0.87 (“almost perfect agreement”); approach modifier, 0.99 (“almost perfect agreement”); and minor osteotomy, 0.55 (“moderate agreement”). Analysis of only major osteotomy plus approach modifier yielded a classification that was “almost perfect” with an average intrarater reliability of 0.90 (0.63–1.00) and an interrater reliability of 0.88 and 0.86 for the two reviews.

Conclusions

The proposed cervical spine osteotomy nomenclature provides the surgeon with a simple, standard description of the various cervical osteotomies. The reliability analysis demonstrated that this system is consistent and directly applicable. Future work will evaluate the relationship between this system and health-related quality of life metrics.

Sagittal plane correction in pedicle subtraction osteotomy using the Xia 3 SUK Direct Vertebral Rotation System: technical note

The Xia 3 SUK Direct Vertebral Rotation (DVR) System was developed for performing the vertebral derotation maneuver in scoliosis surgery. The author applied this device to sagittal plane correction in pedicle subtraction osteotomy for adult spinal deformity. The surgical procedure included 1) preparing secure proximal and distal foundations for correction using mutisegmental pedicle screw-rod fixation (to avoid stress concentration to a specific screw-bone interface), 2) decancellating only the posterior two-thirds of the vertebral column, 3) providing supplemental interbody fusion above and below the osteotomy site (the anterior one-third of the vertebral column and interbody cages serve as an anterior column support and a pivot of correction), 4) closing the osteotomy by gradual approximation of SUK tubes secured to the proximal- and distal-most screw heads, and 5) connecting rods between the proximal and distal screw-rod constructs. Eight consecutive patients with fixed sagittal imbalance were treated using this surgical procedure. No patient required distal fixation points extending to the sacrum and/or pelvis. The sagittal plane correction was 43°. The mean anterior deviation of the C-7 plumb line was improved from 12.7 cm to 4.0 cm immediately after surgery, and it was 6.0 cm at the final follow-up. A pedicle subtraction osteotomy using the Xia 3 SUK DVR System ensures a safe and secure sagittal plane correction in adult spinal deformity.

The vascular supply to the spinal cord and its relationship to anterior spine surgical approaches

BACKGROUND CONTEXT

The understanding of vascular supply to the spinal cord is important given that the evolution of surgical approaches to the spine may bring along the potential for more frequent complications, especially a rare but devastating complication: that of spinal cord ischemia or infarction. To maximally avoid this complication, the relationship between the spinal cord vascularity and the anterior spine surgical approach needs further study.

PURPOSE

To provide a theoretical basis that will allow the spinal surgeon to take appropriate steps to avoid spinal cord ischemia during anterior spinal surgery through anatomic means.

STUDY DESIGN

Spinal cord vascular casting assessment with cadaveric specimen.

METHODS

Twenty adult cadaveric specimens (11 men and 9 women) were obtained for the latex perfusion and vessel dissection. In addition, nine patients (seven men and two women) underwent superselective angiography of the spinal cord. The segmental arterial anastomosis and radiculomedullary vessels in the thoracolumbar region were shown and reviewed.

RESULTS

There were approximately 21 pairs of segmental arteries in the thoracolumbar region. Adjacent segmental arteries were networked with each other. The latex infusion specimens demonstrated 72 anterior radiculomedullary arteries and 177 posterior radiculomedullary arteries in all 20 samples. The anterior and posterior spinal arteries were also networked with each other at several levels. Superselective spinal angiography was consistent with the latex infusion specimens showing.

CONCLUSIONS

The variety of anatomy of spinal cord arterial networks is shown, and the relation between the blood supply of certain spinal levels and the potential ischemic complications during the anterior surgical approach is discussed. It is hopefully of benefit to surgeons, after fully understanding the anatomy of these spinal vascular supply structures, that there may be even greater avoidance of vascular compromise in these challenging operations.

One-stage posterior surgical treatment for lumbosacral tuberculosis with major vertebral body loss and kyphosis

The treatment goals of tuberculous spondylitis are to eradicate infection and to prevent or treat instability, deformity, and neurologic deficit. The purpose of this study was to evaluate the clinical outcomes following chemotherapy with 1-stage posterior debridement, correction, and instrumentation and fusion for the treatment of lumbosacral tuberculosis with major vertebral body loss and kyphosis. Fourteen patients with lumbosacral tuberculosis with major vertebral body loss and kyphosis underwent 1-stage posterior surgery. Clinical assessments included low back ache, Oswestry Disability Index, Scoliosis Research Society-22 scores, neurologic deficit, erythrocyte sedimentation rate, and C-reactive protein level. Radiographic parameters included kyphosis angle, anteroposterior translation, local scoliosis, lumbar lordosis, pelvic parameters, sagittal offset, and fusion. Thorough debridement was performed. Patients were followed for an average of 39.3 months. Constitutional symptoms, low back ache, and functional outcome improved in all patients postoperatively. At final follow-up, Frankel Grade improved by 0 to 2 grades, mean kyphosis angle improvement was 44.3°, and satisfactory spinopelvic and sagittal balance were achieved. Spinal posterolateral fusion was obtained in all patients and no fixation loosening was found at 2-year follow-up. Differences existed between the pre- and postoperative radiographic parameters (P<.05). Correction loss at last follow-up was not statistically significant (P>.05). No surgical complications or infection recurrence occurred. Tuberculosis can be cured and effective correction of kyphosis can be achieved for lumbosacral tuberculosis with major vertebral body loss and kyphosis by performing 1-stage posterior surgery and chemotherapy.

Perioperative Outcomes and Complications of Pedicle Subtraction Osteotomy in Cases With Single Versus Two Attending Surgeons

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To assess the perioperative morbidity of pedicle subtraction osteotomy (PSO) based on the presence of 1 versus 2 attending surgeons.

BACKGROUND SUMMARY

Pedicle subtraction osteotomies are challenging cases with high complication rates and substantial physiological burden on patients. The literature supports the benefits of 2-surgeon strategies in complex cases in other specialties.

METHODS

We reviewed a single institution database of all pedicle subtraction osteotomies (78 cases) from 2005-2010 and divided the cohort into single versus 2-surgeon groups (42 vs. 36 cases, respectively). We performed subset analysis after excluding cases before 2007 and excluding patients with staged anterior and posterior procedures. We analyzed cases for estimated blood loss, length of surgery, length of stay, radiographic analysis, rate of return to the operating room within 30 days, and medical and neurological complications.

RESULTS

The groups were similar when comparing mean number of posterior levels fused, levels decompressed and revision rates, however, the average age of the single surgeon and 2 surgeon groups was 57.6 and 64.3 years, respectively (p = .02). The 2 groups had comparable correction of radiographic parameters. Mean percent estimated blood loss for single versus 2 surgeons was 109% versus 35% (p < .001) and estimated blood loss was 5,278 versus 2,003 mL (p < .001). Average surgical time for single versus 2 surgeons was 7.6 versus 5.0 hours (p < .001). A total of 45% of single-surgeon patients compared with 25% of 2-surgeon patients experienced at least 1 major complication within 30 days. In the single-surgeon group, 19% had unplanned surgery within 30 days, versus 8% in the 2-surgeon group.

CONCLUSIONS

The use of 2 surgeons at an experienced spine deformity center decreases the operative time and estimated blood loss, and may be a key factor in witnessed decreased major complication prevalence. This approach also may decrease the rate of premature case termination and return to operating room in 30 days.

Complications of posterior vertebral resection for spinal deformity

STUDY DESIGN

Retrospective study.

PURPOSE

To evaluate the incidence and risk factors of complications following posterior vertebral resection (PVR) for spinal deformity.

METHODS

A review of 233 patients treated with PVR at one institution over a nine-year period (1997 to 2005) was performed. The average age was 33.5 years. Complications were assessed in terms of surgical techniques (posterior vertebral column resection [PVCR] and decancellation osteotomy) and etiologies of deformity.

RESULTS

Local kyphosis was corrected from 51.4° to 2.7°, thoracic scoliosis 63.9° to 24.5° (62.6% correction), and thoracolumbar or lumbar scoliosis 50.1° to 17.1° (67.6%). The overall incidence of complications was 40.3%. There was no significant difference between PVCR and decancellation osteotomy in the incidence of complications. There were more complications in the older patients (>35 years) than the younger (p < 0.05). Hig her than 3,000 ml of blood loss and 200 minutes of operation time increased the incidence of complications, with significant difference (p < 0.05). More than 5 levels of fusion significantly increased the total number of complications and postoperative neurologic deficit (p < 0.05). Most of the postoperative paraplegia cases had preoperative neurologic deficit. Preoperative kyphosis, especially in tuberculous sequela, had hig her incidences of complications and postoperative neurologic deficit (p < 0.05). More than 40° of kyphosis correction had the tendency to increase complications and postoperative neurologic deficit without statistical significance (p > 0.05). There was 1 mortality case by heart failure. Revision surgery was performed in 15 patients for metal failure or progressing curve.

CONCLUSIONS

The overall incidence of complications of PVR was 40.3%. Older age, abundant blood loss, preoperative kyphosis, and long fusion were risk factors for complications.

Thoracic pedicle subtraction osteotomy in a pediatric patient: a case report

Study design: Case report.

Objective: To describe a case of thoracic pedicle subtraction osteotomy (PSO) for congenital kyphosis in a child.

Background information: Although congenital kyphosis is rare, it is a challenging cause of pediatric myelopathy and frank paralysis. Even less common is the use of PSO for the surgical management of focal congenital kyphosis. We present the case of a child with congenital kyphosis that was managed with a pedicle subtraction osteotomy.

Methods: A detailed history and physical examination were performed with careful review of the patient’s medical records and x-ray studies. A PSO at T11 was performed along with T9 through L1 instrumented posterolateral fusion.

Case description: A 10-year-old girl was evaluated for walking difficulty and a lump on her back. Physical examination revealed a sharp gibbus kyphosis in the lower thoracic spine with tenderness and bilateral back muscle spasms. The patient displayed difficulty with balance lacking a smooth, regular gait rhythm. Clonus and radiculopathy were not present. Plain x-ray of the thoracolumbar spine revealed hyperkyphosis and failure of anterior wall segmentation between T10 and T11 vertebral bodies. Cobb’s angle measured 65 degrees. Due to her symptoms and degree of correction required, we elected to perform a PSO at T11 along with T9 to L1 posterolateral instrumentation fusion. No intraoperative complications occurred. There was a significant improvement in her posture and gait.

Discussion: A thoracic PSO for congenital kyphosis was safely performed with an excellent outcome. To our knowledge, this is the first PSO procedure performed in Uganda.