Posterior spinal fixation using penetrating endplate screws in patients with diffuse idiopathic skeletal hyperostosis-related thoracolumbar fractures

Construct length analysis of type B and C cervical and thoracolumbar fractures

Objectives

The purpose of this study is to identify if construct length affects the rate of surgical complications and instrumentation revision following surgical fixation of subaxial and thoracolumbar Type B and C fractures. This study evaluates the effect of ankylosing spondylitis/diffuse idiopathic skeletal hyperostosis (AS/DISH) within this population on outcomes.

Methods

Retrospective review of 91 cervical and 89 thoracolumbar Type B and C fractures. Groups were divided by construct length for analysis: short-segment (constructs spanning two or less segments adjacent to the fracture) and long-segment (constructs spanning more than two segments adjacent to the vertebral fracture).

Results

For cervical fractures, construct length did not impact surgical complications (P = 0.641), surgical hardware revision (P = 0.167), or kyphotic change (P = 0.994). For thoracolumbar fractures, construct length did not impact surgical complications (P = 0.508), surgical hardware revision (P = 0.224), and kyphotic change (P = 0.278). Cervical Type B fractures were nonsignificantly more likely to have worsened kyphosis (P = 0.058) than Type C fractures. Assessing all regions of the spine, a diagnosis of AS/DISH was associated with an increase in kyphosis (P = 0.030) and a diagnosis of osteoporosis was associated with surgical hardware failure (P = 0.006).

Conclusion

Patients with short-segment instrumentation have similar surgical outcomes and changes in kyphosis compared to those with long-segment instrumentation. A diagnosis of AS/DISH or osteoporosis was associated with worse surgical outcomes.

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.

The Impact of Diffuse Idiopathic Skeletal Hyperostosis on Nutritional Status, Neurological Outcome, and Perioperative Complications in Patients with Cervical Spinal Cord Injury

This retrospective study aimed to investigate the characteristics of patients with cervical spinal cord injuries (CSCI) with diffuse idiopathic skeletal hyperostosis (DISH). We included 153 consecutive patients with CSCI who underwent posterior decompression and fusion surgery. The patients were divided into two groups based on the presence of DISH. Patient characteristics, neurological status on admission, nutritional status, perioperative laboratory variables, complications, neurological outcomes at discharge, and medical costs were compared between the groups. The DISH group (n = 24) had significantly older patients (72.1 vs. 65.9, p = 0.036), more patients with low-impact trauma (62.5% vs. 34.1%, p = 0.009), and a lower preoperative prognostic nutritional index on admission (39.8 vs. 42.5, p = 0.014) than the non-DISH group (n =129). Patients with DISH had significantly higher rates of ventilator management (16.7% vs. 3.1%, p = 0.022) and pneumonia (29.2% vs. 8.5%, p = 0.010). There was no significant difference in medical costs and neurological outcomes on discharge. Patients with CSCI and DISH were older, had poor nutritional status, and were prone to postoperative respiratory complications, while no differences were found between the neurological outcomes of patients with CSCI with and without DISH.

Vertebral fracture at the caudal end of diffuse idiopathic skeletal hyperostosis treated with vertebroplasty via double-endplate penetrating screw trajectory and posterior spinal fixation with a new hybrid strategy using cement-augmented fenestrated pedicle screws

Vertebral fractures in diffuse idiopathic skeletal hyperostosis (DISH) are often unstable. We encountered a case of vertebral fracture at the caudal end of DISH in which vertebroplasty was performed via a double endplate penetrating screw (DEPS) trajectory, and short posterior fixation was performed using the DEPS technique on the cranial vertebrae, including the fractured vertebra; conventional pedicle screw to the caudal vertebrae; and cement-augmented fenestrated pedicle screws to the caudal end vertebra. A 93-year-old man presented with a vertebral fracture at the caudal end of a DISH after a fall. He underwent surgery for lower back pain due to spinal instability. Vertebroplasty via DEPS trajectory can shorten the posterior fixation range. Using cement-augmented fenestrated pedicle screws to the caudal end vertebra enables balancing of the posterior fixation force. This strategy should be considered when a vertebral fracture is found at the caudal end of the DISH.

Pneumothorax by Penetrating Endplate Screw for Diffuse Idiopathic Skeletal Hyperostosis-Related Thoracolumbar Fracture

Pneumothorax is a rare surgical complication in spinal surgery with thoracic pedicle screws. The penetrating endplate screw (PES) technique has been developed as a strong alternative spinal anchor to conventional pedicle screws for diffuse idiopathic skeletal hyperostosis (DISH). We present an intraoperative pneumothorax without deviation to the thoracic during the maneuver of the PES. A 56-year-old male who presented with non-union of DISH-related T12 vertebral fracture underwent T12 kyphoplasty and T10-L2 posterior fixation using the PES technique. The left pneumothorax was developed postoperatively without screw deviation to the thorax throughout screw insertion. Postoperative CT suggested that a displaced rib head by the lateral misposition of the screw at the inserting point and the pedicle level might injure the pleura. Spine surgeons should know that the lateral insertion of PES has a potential risk for pneumothorax by the displacement of the rib head because of screw trajectory from caudal to cranial apart from conventional pedicle screw.

Diffuse Idiopathic Skeletal Hyperostosis with Severely Displaced Spine Fracture Managed with Posterior Approach Alone: Case Reports and Literature Review

Diffuse idiopathic skeletal hyperostosis (DISH) is a condition in which minor trauma can cause extremely unstable vertebral fractures. Spinal fractures associated with DISH are prone to instability due to the large moment of lever arm and secondary neurological deterioration; hence, surgical internal fixation is considered necessary. On the other hand, some reports suggest that patients with DISH have a high osteogenic potential. In this report, we describe three patients with DISH. These patients had spinal injuries that resulted in a large gap, for which anterior fixation with bone graft would generally be considered due to comminuted fractures. However, we achieved good bony fusion with posterior fixation alone, without forcible correction.

Internal fixation for fragility fracture of pelvis in a patient with ankylosing spondylitis

Ankylosing spondylitis is a common inflammatory rheumatic disease with a prevalence of 0.1 %–1.4 %. The most common vertebral fractures associated with ankylosing spondylitis are cervical spine injuries due to low-energy trauma, whereas pelvic fractures are rare. Conversely, fragility fracture of the pelvis is a fracture of the pelvic ring caused by low-energy trauma with a background of bone fragility. In recent years, minimally invasive surgery for early mobilization of displaced fragility fracture of the pelvis has been reported. We report herein a case of a 91-year-old male with ankylosing spondylitis who underwent internal fixation for fragility fracture of his pelvis. He was brought to the emergency room with a complaint of pain in the right hip after a fall from a standing position at home. Computed tomography showed a fracture of the right pubis and a fracture, which crossed the sacrum from the ilium with a maximum dislocation. There was also extensive ossification of the anterior longitudinal ligament in the thoracolumbar spine and bony ankylosis of both sacroiliac joints. The diagnosis after the injury was fragility fracture of the pelvis, which complicated by ankylosing spondylitis. The fracture type did not match the Rommens and Hofmann classification criteria. Iliac intramedullary stabilization was performed in accordance with the treatment of Rommens and Hofmann classification type IIIa. The patient's pain reduced a day after the surgery, and he was able to use a wheelchair. He was able to walk with a cane two months after the surgery, and bone union was achieved four months postsurgery.

Iliac intramedullary stabilization was useful in patients with atypical fractures a) that did not fit the Rommens and Hofmann classification criteria owing to the presence of ankylosing spondylitis, and b) in cases wherein strong fixation was considered necessary.

Life Expectancy Is Poor in Patients with Diffuse Idiopathic Skeletal Hyperostosis-Related Pyogenic Vertebral Osteomyelitis

Introduction

Pyogenic vertebral osteomyelitis (PVO) is an uncommon but life-threatening infectious disease. Diffuse idiopathic skeletal hyperostosis (DISH) is an age-related disorder and sometimes problematic in terms of spinal instability or high mortality, especially in cases of DISH-related fracture. Meanwhile, no reports have focused on the impact of DISH on the clinical outcomes after treatment for PVO. We hypothesized that PVO occurring at DISH-related segments might contribute to poor clinical results or high mortality rates. The purpose of this study was to investigate the impact of DISH on mortality after treatment for PVO in a retrospective cohort study.

Methods

This study involved patients who were hospitalized and treated for PVO at a single institution. DISH-related PVO was defined as PVO within a segment ossified by DISH or PVO at the neighboring intervertebral level of the segment ossified by DISH. Differences in mortality between patients with DISH-related and non-DISH-related PVO were investigated.

Results

This study included 55 patients. DISH-related PVO was observed in 13 patients. The mortality rate was significantly higher in patients with DISH-related PVO than in those with non-DISH-related PVO (62% and 23%, respectively; p=0.016). Propensity score-adjusted analysis showed that DISH-related PVO was an independent risk factor for mortality (adjusted hazard ratio, 2.79; p=0.034). The survival probability was significantly shorter in patients with DISH-related PVO than in those with non-DISH-related PVO (p=0.006). PVO in which the intravertebral body was the center of involvement was significantly more common in DISH-related PVO than in non-DISH-related PVO (38% and 5%, respectively; p=0.006).

Conclusions

DISH-related PVO was associated with a higher mortality rate and shorter life expectancy than non-DISH-related PVO. Similar to advanced age, PVO at the segment ossified by DISH should be recognized as a risk factor for mortality when choosing the optimal treatment strategy.

Penetrating Endplate Screw Fixation for Thoracolumbar Pathological Fracture of Diffuse Idiopathic Skeletal Hyperostosis

With the advancement of cancer treatment and minimally invasive surgery, the indications for surgery for metastatic spinal tumors are expanding. Diffuse idiopathic skeletal hyperostosis (DISH) is a noninflammatory skeletal disease characterized by calcification and ossification of ligaments and entheses. In Japan, the prevalence of DISH is increasing with its superaging society. The purpose of this article is to report a case of applying a novel screw technique for pathological fracture in a patient with DISH and spinal metastasis. An 80-year-old man with spinal metastasis presented with acute onset of severe back pain, and investigations revealed a fracture of a metastatic lesion in T10–T12 in the range of DISH. We performed posterior fixation with a percutaneous pedicle screw system using a penetrating endplate technique. The patient's back pain improved, and he was able to mobilize with minimal assistance and survived for 8 months with a good quality of life. Spinal fracture accompanied by DISH sometimes occurs with severe instability because of injury across 3-column injury and its long lever arm. Spinal instability neoplastic score indicates instability of pathological fractures of spinal metastases but needs to be evaluated carefully when DISH is present. The prevalence of DISH is increasing in the elderly, and penetrating endplate screws can be an effective option in posterior fusion surgery for patients with DISH and spinal metastases.

Case Report: Identifying Andersson-Like Lesions in Diffuse Idiopathic Skeletal Hyperostosis

Andersson lesions (ALs) in ankylosing spondylitis (AS) pose a severe risk to the stability of ankylosed spine, which might result in significant deterioration of spinal cord function after traumatic or inflammatory causes. Herein, erosive discovertebral lesions in diffuse idiopathic skeletal hyperostosis (DISH) presented important clinical similarities to AL in AS, but failed to completely recognize unstable spinal lesions. Therefore, we pioneered to identify spinal discovertebral lesions similar to Andersson-like lesions (ALLs) in DISH, followed by the characterization and summarization of the etiology, radiology, laboratory results, clinical symptoms, and treatment strategies for AL in AS with ALL in DISH. By characterizing the ALL in DISH cases, we showed that the ALL was mainly traumatic and established at the junction of focal stress between two adjacent ossified level arms. Erosive discovertebral ALLs were formed after trivial stress of direct impact and could be subdivided into transdiscal, transvertebral, and discovertebral types radiologically. Patients who presented with ALL frequently suffered from consistent back pain clinically and experienced a decrease in motion ability that could reflect skeletal stability, which received treatment effectiveness after conservative external spinal immobilization or further surgical internal fixation, indicating the significance of recognizing ALL in the ankylosed DISH spine to further maintain spinal stability in order to prevent catastrophic neurologic sequelae. Our work highlighted the clinical relevance of ALL in DISH in comparison with AL in AS, which provided broader insight to identify ALL in DISH, thus facilitating early intervention against DISH deterioration.