Spinal fractures in diffuse idiopathic skeletal hyperostosis: Advantages of percutaneous pedicle screw fixation

Outcomes of Balloon Kyphoplasty for Vertebral Compression Fractures in Patients with Diffuse Idiopathic Skeletal Hyperostosis at the Distal End or Adjacent Vertebra of the Fused Segments

STUDY DESIGN

A retrospective cohort study.

PURPOSE

To investigate the outcomes of balloon kyphoplasty (BKP) for vertebral compression fractures (VCFs) at the distal end or adjacent vertebra of the fused segments in patients with diffuse idiopathic skeletal hyperostosis (DISH).

OVERVIEW OF LITERATURE

Vertebral fractures in the midportion of the fused segments in patients with DISH are generally unstable; thus, immobilization is recommended. However, VCFs classified as type A in the AO classification are observed at the distal end and adjacent vertebra of the fused segments, and treatment strategies for VCFs associated with DISH remain controversial.

METHODS

The outcomes of 72 patients who underwent BKP for VCFs between 2015 and 2021 were retrospectively investigated. Patients with DISH were assigned to group D (n=21), whereas those without DISH were assigned to group ND (n=51). Back pain, incidence of subsequent adjacent fractures, reoperation rates, and local kyphosis were statistically analyzed.

RESULTS

VCFs in group D occurred at the distal end or adjacent vertebra of the fused segments, and no fractures occurred in the midportion of the fused segment. Back pain improved in both groups, with no significant differences between them. Subsequent adjacent fractures were observed in three of the 21 patients in group D and 11 of the 51 patients in group ND, with no significant difference between them. Reoperation was performed in one patient each in groups D and ND, with no significant difference between the groups. Postoperatively, local kyphosis progressed significantly in group D.

CONCLUSIONS

Although local kyphosis is more advanced in patients with DISH, BKP is effective for VCFs at the distal end or adjacent vertebra of the fused segments and may be useful in older patients with high complication rates.

Forcefully engaging rods into tulips with gap discrepancy leading to pedicle screw loosening-a biomechanical analysis using long porcine spine segments

BACKGROUND CONTEXT

Long-segment pedicle screw instrumentation is widely used to treat complex spinal disorders. Rods are routinely precontoured to maximize assistance on the correcting side of the deformity, but there often exists a residual gap discrepancy between the precontoured rods and screw tulips. No previous research has investigated the diminished pullout strength of the most proximal or distal pedicle screw resulting from a mismatched rod in long-segment pedicle screw instrumentation.

PURPOSE

The present study aimed to investigate the decreased pullout force of pedicle screws affected by the gap discrepancy when forcefully engaging a mismatched rod into a tulip in a normal-density porcine spine.

STUDY DESIGN

The pedicle screw fixation strength under axial pullout force was compared among three different gap discrepancies between rods and tulips using long porcine spine segments.

METHODS

Twelve porcine lumbar vertebrae (L3-L6) were implanted with pedicle screws and rods. Screws on one side had no gap between the tulip and rod (0-mm group), while the most proximal screw on the other side had an intentional gap of 3 mm (3-mm group) or 6 mm (6-mm group). Three hours after forcefully engaging the rod into the tulips at room temperature, the set screws in all specimens were loosened, and each specimen was dissected into individual vertebrae for subsequent pullout testing.

RESULTS

The control group exhibited significantly greater pullout strength (1987.68 ± 126.80 N) than the groups from different rod-tulip configurations (p<.05), with significantly greater strength in the 3-mm group (945.62 ± 97.43 N) than the 6-mm group (655.30 ± 194.49 N) (p<.05). Only 47.6% and 33.0% of the pullout strength was retained in the 3-mm and 6-mm groups, respectively, compared to the control group.

CONCLUSIONS

Gap discrepancies between rods and tulips can significantly reduce pedicle screw pullout strength, with a correlation between decreased strength and increased gaps. Surgeons should avoid forcefully engaging mismatched rods and consider well-fitted contoured rods in spinal surgery to minimize the risk of screw loosening.

CLINICAL SIGNIFICANCE

The gap discrepancy between rod and tulip significantly affected pullout strength, with greater gaps leading to reduced strength. Forcefully engaging mismatched rods into tulips in degenerative spinal surgery should be avoided to minimize the risk of early screw pullout.

Management of Thoracolumbar Vertebral Fractures and Dislocations in Patients with Ankylosing Conditions of the Spine

Ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) are bone-forming spinal conditions which inherently increase spine rigidity and place patients at a higher risk for thoracolumbar fractures. Due to the long lever-arm associated with their pathology, these fractures are frequently unstable and may significantly displace leading to catastrophic neurologic consequences. Operative and non-operative management are considerations in these fractures. However conservative measures including immobilization and bracing are typically reserved for non-displaced or incomplete fractures, or in patients for whom surgery poses a high risk. Thus, first line treatment is often surgery which has historically been an open posterior spinal fusion. Recent techniques such as minimally invasive surgery (MIS) and robotic surgery have shown promising lower complication rates as compared to open techniques, however these methods need to be further validated.

Comparison of the Fixation Strengths of Screws between the Traditional Trajectory and the Single and Double Endplate Penetrating Screw Trajectories Using Osteoporotic Vertebral Body Models Based on the Finite Element Method

STUDY DESIGN

This is a finite element (FE) study.

PURPOSE

To compare the fixation strength of traditional trajectory (TT) and single and double endplate penetrating screw trajectories (SEPST/DEPST) to the osteoporotic vertebral body model based on the FE method.

OVERVIEW OF LITERATURE

SEPST/DEPST have been developed to enhance the fixation strength in patients with diffuse idiopathic hyperostosis (DISH). This technique was also applied to patients with osteoporosis. However, determining the superiority of SEPST/ DEPST is difficult because of the heterogeneous patient backgrounds.

METHODS

Twenty vertebrae (T12 and L1) from 10 patients with osteoporosis (two males and eight females; mean age, 74.7 years) were obtained to create the 10 FE models. First, a single screw was placed with TT and SEPST/DEPST, and the fixation strength was compared by axial pullout strength (POS) and multidirectional loading tests. Second, two screws were placed on the bilateral pedicles with TT and SEPST/DEPST, and the fixation force of the vertebrae in the constructs in flexion, extension, lateral flexion, and axial rotation was examined.

RESULTS

SEPST and DEPST had 140% and 171% higher POS values than TT, respectively, and the DEPST result was statistically significant (p =0.007). The multidirectional fixation strength was significantly higher in DEPST and SEPST than in TT in the cranial, caudal, and medial directions (p <0.05) but not in the lateral direction (p =0.05). The vertebral fracture strength at the lower instrumented vertebra of the DEPST tended to be higher than that of TT. The vertebral motion angles in SEPST and DEPST were significantly smaller in lateral bending (p =0.02) and tended to be smaller in flexion and extension than in TT (p =0.13).

CONCLUSIONS

This study may provide useful information for spine surgeons in deciding whether to choose the SEPS or DEPS technique for augmenting fixation in osteoporotic vertebral fracture surgery.

Percutaneous versus traditional open approaches for the treatment of thoracolumbar fractures in patients without neurologic deficits: a meta-analysis of 35 cohort studies

At present, percutaneous surgery is widely used to treat thoracolumbar fractures. However, the actual safety, feasibility, and effectiveness of percutaneous surgery are not clear. Through systematic review and meta-analysis, we compared the efficacies of percutaneous pedicle screw fixation and open pedicle screw fixation in the treatment of thoracolumbar fractures without nerve root symptoms. We systematically searched the PubMed, Embase, and Cochrane libraries for articles published on or before June 2023. All results were evaluated by standard methods recommended for meta-analysis, continuous data were expressed by standard mean differences (SMDs), and binary variables were analyzed by odds ratios (ORs) and 95% confidence intervals (95% CIs). We also explored the main sources of heterogeneity and the stability of the results through sensitivity analysis, Begg's funnel plots, and Egger's test. Thirty-five cohort studies with a total of 3039 patients were included. The study found that patients who undergo percutaneous approaches have less intraoperative blood loss (IBL), shorter length of hospital stay (LOS), shorter operation time, and shorter incision. Moreover, percutaneous approaches had more advantages in terms of visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, and infection rates. However, there was no significant difference in anterior vertebral body height (AVB), Cobb angle (CA), or screw errors between the two groups. In the long run, the clinical and surgical results of the percutaneous approach are better than those of the open approach, but the radiological results of both operations do not seem to show an advantage for any specific approach. Because of publication bias and heterogeneity, our findings must be interpreted with caution. However, this paper will provide some support for clinicians to choose suitable surgical methods for the treatment of thoracolumbar fractures.

Results of in situ fixation of Andersson lesion by posterior approach in 35 cases

STUDY OBJECTIVE

Due to the rarity of the Andersson lesion (AL), the literature is ambiguous regarding the type of surgical fixation, need for debridement and deformity correction. The purpose of this retrospective study is to evaluate the efficacy, feasibility and functional outcome of posterior fixation in AL.

MATERIALS AND METHODS

This study included 35 patients having thoracolumbar AL operated for in situ fixation and fusion with minimum of 24-month follow-up. VAS (Visual Analogue Score) back pain, ODI (Oswestry Disability Index), Frankel's grade were compared and analyzed. Union status was noted with complications.

RESULTS

The mean age of 35 patients was 56.34(± 11.3) years with average follow-up of 51.49 months. Two patients had AL at two levels. 27/37 AL were at discal level. Average estimated blood loss (EBL) was 276.43 ml and duration of surgery was 130.43 min. On an average, operated segments needed 7.77 screws. There were ten minor complications without long-term sequel. Neurological improvement was noted in 30 patients. Average preoperative VAS score improved from 8.69 to 3.14, ODI score improved from 68.76 to 18.77 at final follow-up which were significant (p < 0.05). There was significant improvement in Frankel's grading (Z = - 4.354, P = 0.00).

CONCLUSIONS

Surgical management of AL by posterior approach and posterior stabilization can give satisfactory results without the need of extensive anterior reconstruction, bone grafting or deformity correction procedures without added morbidity and complications.

Surgical treatment of thoracolumbar fracture in ankylosing spondylitis: A comparison of percutaneous and open techniques

BACKGROUND CONTEXT

Posterior percutaneous long-segment internal fixation and open fixation with long-segment screws have been used to treat thoracolumbar fractures in ankylosing spondylitis patients.

PURPOSE

To observe the clinical effect of posterior percutaneous long-segment internal fixation in 26 ankylosing spondylitis (AS) patients with thoracolumbar fractures.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Forty-seven AS patients who were diagnosed with thoracolumbar fractures and treated from December 2014 to December 2018.

OUTCOME MEASURES

Visual analog scale score, Cobb angle, American Spinal Injury Association Grade, SF-Qualiveen score, pedicle screw misplacement rate, operative duration, blood loss, complications, bed rest duration and modified MacNab score.

METHODS

All patients were divided into the percutaneous group (PG) and the open group. Twenty-six patients were treated with percutaneous long-segment internal fixation, and the remaining 21 underwent open fixation with long-segment screws. The minimum follow-up period was 12 months.

RESULTS

The operations were successful in both groups. A patient in the PG showed class C wound healing, while the others showed class A healing, and some patients experienced perioperative complications. All patients were followed up for 12-48 months (mean, 33.81 months), and all patients showed clinical osseous fracture healing. Significant differences were found in operative duration, intraoperative blood loss and postoperative bed rest duration between the two groups (P < 0.05). No significant difference was found in improvement of the visual analog scale score, Cobb angle of spinal kyphosis or neurological function after the operation (P > 0.05).

CONCLUSIONS

As a minimally invasive procedure, posterior percutaneous long-segment internal fixation requires less time, results in less blood loss and causes less trauma. This procedure can also improve patients' pain, neurological function and kyphotic deformity and achieve effects similar to those of traditional methods. With this curative clinical effect, this procedure can be used as an ideal surgical treatment for thoracolumbar fractures in AS patients, especially for elderly patients with underlying diseases and high surgical risk.

Percutaneous kyphoplasty for the treatment of diffuse idiopathic skeletal hyperostosis with vertebral fractures: A case report and treatment review

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic metabolic condition characterized by new bone formation mainly at the anterolateral spine. Surgery such as screw fixation is commonly used for DISH patients who also suffer from vertebral fractures. In this case report, we share a DISH case with lumbar vertebral fracture and osteoporosis who underwent percutaneous kyphoplasty plus braces and medication. Percutaneous kyphoplasty, considered as minimally invasive surgery, may be another treatment option with the advantages of less trauma and faster recovery. The clinical information and radiological findings are described and treatments for DISH with vertebral fractures are then briefly reviewed.

Comparative Study of S2-Alar-Iliac Screw Trajectories between Males and Females Using Three-Dimensional Computed Tomography Analysis: The True Lateral Angulation of the S2-Alar-Iliac Screw in the Axial Plane

The S2 alar-iliac screw (S2AIS) is commonly used for long spinal fusion as a rigid distal foundation in spinal deformity surgeries, and it is also used in percutaneous sacropelvic fixation for providing an in-line connection to the proximal spinal constructs without using offset connectors. Although the pelvic shape is different between males and females, reports on S2AIS trajectories according to gender have been scarce in the literature. In this paper, S2AIS trajectories are compared between males and females using pelvic three-dimensional computed tomography (3D-CT) in a normal Japanese population. After resetting the caudal angulation in CT-imaging plane manipulation, the angulation of S2AIS was more lateral in the axial plane and more horizontal in the coronal plane in females. Mean distances from the midline to starting points of S2AIS tended to be shorter in females, whereas mean distances from the midline to the posterior superior iliac spine was significantly longer in females. We also found that there were positive correlations between the patients’ height and the maximal lengths of S2AISs, and the patients’ height and minimal areas of S2AIS pathways. Our results are useful not only for conventional open spinal surgery, but also for minimally invasive spine surgery.

Diffuse Idiopathic Skeletal Hyperostosis of the Spine: Pathophysiology, Diagnosis, and Management

Diffuse idiopathic skeletal hyperostosis (DISH) is an ankylosing condition affecting up to 32.5% of the general cohort. Although often asymptomatic, affected individuals may present with back pain, stiffness, dysphagia, functional decline, and neurologic deficits. Radiographically, DISH is characterized by flowing ossifications along the anterior spine spanning ≥4 vertebral bodies. Although the etiology of DISH remains unknown, diabetes mellitus and other metabolic derangements are strongly associated with DISH. Importantly, spinal ankylosis in DISH predisposes patients to unstable spine fractures from low-energy trauma, and careful consideration must be taken in managing these patients. This article reviews the epidemiology and pathophysiology of DISH, and its clinical findings, diagnostic criteria, and management.

Thoracic spondylotic myelopathy presumably caused by diffuse idiopathic skeletal hyperostosis in a patient who underwent decompression and percutaneous pedicle screw fixation

A 74-year-old man developed bilateral lower limb spastic paresis. He was diagnosed with thoracic spondylotic myelopathy presumably caused by mechanical stress that was generated in the intervertebral space (T1-T2) between a vertebral bone bridge (C5-T1) due to diffuse idiopathic skeletal hyperostosis after anterior fixation of the lower cervical spine and a vertebral bone bridge (T2-T7) due to diffuse idiopathic skeletal hyperostosis in the upper thoracic spine. Treatment included posterior decompression (T1-T2 laminectomy) and percutaneous pedicle screw fixation at the C7-T4 level. Six months after surgery, the patient could walk with a cane, and the vertebral bodies T1-T2 were bridged without bone grafting. For thoracic spondylotic myelopathy associated with diffuse idiopathic skeletal hyperostosis, decompression and percutaneous pedicle screw fixation are effective therapies.

Comparative analysis of clinical factors associated with pedicle screw pull-out during or immediately after surgery between intraoperative cone-beam computed tomography and postoperative computed tomography

Background

No studies to date have elucidated the clinical factors associated with pedicle screw pull-out during or immediately after surgery. The aim of this study was to assess the frequency of pedicle screw pull-out by comparing intraoperative scans obtained using cone-beam computed tomography (CBCT) with postoperative scans obtained using computed tomography (CT). We also sought to determine the incidence of pedicle screw pull-out and identify relevant risk factors.

Methods

This was a retrospective analysis of prospectively collected data for 742 pedicle screws placed in 76 consecutive patients who underwent at least triple-level posterior fixation for thoracic or lumbar spinal injury, spinal metastasis, or pyogenic spondylitis between April 2014 and July 2020. Pedicle screw pull-out distance in the axial and sagittal planes was compared between CT scans obtained 2 days postoperatively and CBCT images acquired intraoperatively. Risk factors associated with pedicle screw pull-out were investigated by multivariate logistic regression analysis.

Results

Pedicle screw pull-out was seen with 58 pedicle screws (7.8%) in 26 patients (34.2%). There were significant differences in age, number of fused segments, frequency of diffuse idiopathic skeletal hyperostosis (DISH), and medical history of osteoporosis for pedicle screw pull-out. Risk factors for pedicle screw pull-out were older age (odds ratio 1.07, 95% confidence interval 1.02–1.130) and a diagnosis of DISH (odds ratio 3.35, 95% confidence interval 1.12–10.00). Several cases suggest that use of connecting rods was an important factor in intraoperative pedicle screw pull-out.

Conclusions

Our findings suggest that age, number of fused segments, presence of DISH, and medical history of osteoporosis are risk factors for pedicle screw pull-out, with the greatest being older age and DISH.

Minimally Invasive versus Conventional Open Surgery for Fixation of Spinal Fracture in Ankylosed Spine

Introduction:

This was a retrospective study aimed to investigate the perioperative outcomes of long construct minimally invasive spinal stabilisation (MISt) using percutaneous pedicle screws (PPS) versus conventional open spinal surgery in the treatment of spinal fracture in ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH).

Material and Methods:

Twenty-one patients with AS and DISH who were surgically treated between 2009 and 2017 were recruited. Outcomes of interest included operative time, intra-operative blood loss, complications, duration of hospital stay and fracture union rate.

Results:

Mean age was 69.2 ± 9.9 years. Seven patients had AS and 14 patients had DISH. 17 patients sustained AO type B3 fracture and 4 patients had type B1 fracture. Spinal trauma among these patients mostly involved thoracic spine (61.9%), followed by lumbar (28.6%) and cervical spine (9.5%). MISt using PPS was performed in 14 patients (66.7%) whereas open surgery in 7 patients (33.3%). Mean number of instrumentation level was 7.9 ± 1.6. Mean operative time in MISt and open group was 179.3 ± 42.3 minutes and 253.6 ± 98.7 minutes, respectively (p=0.028). Mean intra-operative blood loss in MISt and open group was 185.7 ± 86.4ml and 885.7 ± 338.8ml, respectively (p<0.001). Complications and union rate were comparable between both groups.

Conclusion:

MISt using PPS lowers the operative time and reduces intra-operative blood loss in vertebral fractures in ankylosed disorders. However, it does not reduce the perioperative complication rate due to the premorbid status of the patients. There was no significant difference in the union rate between MISt and open surgery.

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

Introduction

We have developed the single or double endplates penetrating screw (SEPS/DEPS) technique, which is a novel percutaneous pedicle screw (PPS) insertion technique suitable for osteoporotic vertebral body fracture (OVF) patients with diffuse idiopathic skeletal hyperostosis (DISH). This study aims to compare the effectiveness of this SEPS/DEPS technique with the conventional pedicle screw technique.

Methods

The screw is inserted upward from the outer caudal side of the pedicle toward the inner cranial side. Vertebrae affected with DISH were inserted with screws using the SEPS/DEPS technique, whereas non-fused vertebrae were inserted with screws using the conventional PPS technique. Twelve OVF patients with DISH were included in this study; three with SEPS/DEPS technique only and nine with a hybrid of both the DEPS and the conventional PPS techniques. As a control group, 12 OVF patients with DISH treated by conventional PPS. The rates of implant failures and of surgical complications were compared between the SEPS/DEPS group and the control group. The insertion torque was measured and compared between DEPS and conventional PPS in three hybrid patients.

Results

In the SEPS/DEPS group, 70 screws were inserted with the SEPS/DEPS technique and 56 screws were inserted with the conventional PPS technique. In the control group, 116 screws were inserted using the conventional PPS and the PS techniques. The loosening of screws was significantly less in screws inserted with the SEPS/DEPS technique (0/70 screws, 0%) than with screws inserted with the conventional technique (12/116 screws, 10.3%). The average insertion torque of DEPS was 2.25 Nm, which was 134% higher than that of conventional PPS which was 1.64 Nm (p = 0.04).

Conclusions

This novel SEPS/DEPS technique has a higher insertion torque compared with the conventional PPS techniques and demonstrated itself to be an effective option for patients with concomitant bone fragility due to DISH.