[Osteoporotic vertebral crush fractures with severe neurologic manifestations. Apropos of 6 cases]

Surgical options for osteoporotic vertebral compression fractures complicated with spinal deformity and neurologic deficit

INTRODUCTION

This paper describes surgical options for Osteoporotic vertebral compression fracture (OVCF) with acute flexible or chronic rigid kyphosis, and pseudarthrosis complicated with pain and neurologic deficit.

METHODS

This study has two components. a) A prospective clinical study of surgical treatment of 31 patients (age: 69±11 years) with either acute flexible or progressive pseudarthrotic kyphosis manifested with severe pain or neurological deficit between 2010 and 2014. Eleven patients exhibited neurocompression (Frankel B, C, D). Surgery consisted in indirect reduction, kyphoplasty, and short posterior instrumentation in 28 patients and multilevel instrumentation in three. b) The second component involved a literature search of OVCF complicated with acute or painful chronic deformities and neurologic deficit, managed with open surgical approach.

RESULTS

Indirect reduction, kyphoplasty and short posterior stabilization can restore satisfactory anatomic alignment and neurological deficit. Multilevel instrumentation was used for rigid long kyphosis. Complications were related to a) screw pull out and junctional kyphosis (4 patients) one of the patients also developed anterior migration of cement, b) cement leakage (4 patients). L5 radiculopathy occurred in one patient. The others remained asymptomatic. The literature review concluded that corpectomy with anterior, posterior or combined instrumentations is indicated for burst fractures, or rigid kyphosis with neurocompression. Prompt decompression with anatomical alignment may restore paraplegia. Complications were germane to osteoporotic bone predisposing to hardware loosening or cut out and dislodgement of instrumentation.

DISCUSSION

Neurologic deficit associated with fractures or progressive pseudarthrotic kyphosis effectively may respond to indirect postural reduction, kyphoplasty and posterior percutaneous short segment transpedicle instrumentation. For burst fractures and rigid chronic kyphosis corpectomy reconstructed with cages and anterior, or posterior or combined instrumentations can restore and maintain normal anatomy. The following guidelines for optimal surgical instrumentation have been established: To prevent screw loosening and junctional kyphosis the instrumentation should not end within the kyphotic segment. Screws for anterior instrumentation should penetrate the contralateral cortex. Multiple site of fixation or combined anterior and posterior instrumentations dissipate stresses at any one site. Augmentation of transpedicle screw fixation with cement is a sound technical principle. Cement should inserted in a doughy state with minimal pressure to prevent cement complications.

Delayed Neurological Deficits after Osteoporotic Vertebral Fractures: Clinical Outcomes after Surgery

Study Design

Retrospective cohort.

Purpose

To review the clinical presentation of operated patients with delayed neurological deficits after osteoporotic vertebral fractures (OVFs).

Overview of Literature

Delayed neurological deficits can occur from 1 week to 5.7 months after OVFs. Baba has reported 78% good-to-excellent improvement (i.e., ≥50%) after 20 posterior (Cotrel-Dubousset) and 7 anterior (Kaneda in 4, Zielke ventral derotational spondylodesis in 2, and un-instrumented anterior fusion in 1) fusions. Predictive factors for neurological deficits include burst type, vacuum sign, kyphosis, angular instability, and retropulsion.

Methods

Patients with neurological deficits after OVF who received spinal operations between 2000 and 2016 were included.

Results

Totally, 28 patients with a mean age of 77 years underwent surgery. Neurological deficits occurred at an average of 5.4 weeks after the onset of back pain. The most common site was L1. Burst fracture was present in 14 patients and vacuum sign in seven. Surgery was performed within an average of 3.9 days of the onset of neurological deficit. Baba's score improved significantly from 5.96 to 9.81, with good-to-excellent improvement in 18 (64%) patients. Better outcomes based on Baba's scores (improvement>60% [median]) were associated with compression fractures, preoperative retropulsion of <41%, and correction of >16%. Poor improvement in Baba's scores (<25%) was associated with surgical complications and burst fracture type. Twenty-two patients (79%) regained walking ability, and seven of 15 (47%) patients demonstrated improved sphincter control at the latest follow-up. Six Frankel grade B patients did not achieve neurological recovery, four of whom exhibited postoperative surgical complications and died at 2 years because of medical problems. Implant migration occurred in six patients, albeit this was of no clinical significance.

Conclusions

Although OVFs are commonly considered benign, delayed neurological deficits can occur. The significant improvement in clinical function after surgery for neurological deficits is associated with compression (and not burst) fractures, lack of surgical complications, and optimal restoration of retropulsion.

Osteoporotic vertebral compression fracture causing neurologic deficit

Osteoporotic vertebral fractures rarely cause neurologic deficits. We discuss a 69-year-old man who presented with the signs of impaired function of the left L5 nerve root. Imaging revealed a fracture of the posterior upper edge of the fifth lumbar vertebra with a bony fragment protruding into the spinal canal. The fracture was attributed to sneezing and coughing in this man with osteoporosis secondary to hypogonadism. Literature search revealed 64 cases of neurologic deficit associated with osteoporotic vertebral fracture. Most osteoporotic fractures with neurologic deficit (72%) occur at the thoracolumbar junction. The symptomatology of girdle-like pain and hypesthesia is not specific and may be misinterpreted as an abdominal problem or renal pain. A typical sign is the slowly progressive neurologic deficit, occurring spontaneously or after minor trauma such as a fall on the buttocks. Surgical treatment confirms the diagnosis and usually leads to remission of the neurologic signs. With increasing frequency of osteoporotic fractures in the developed world because of the expanding elderly population, cases with neurologic problems become more important.

Principles of management of osteometabolic disorders affecting the aging spine

Osteoporosis is the most common contributing factor of spinal fractures, which characteristically are not generally known to produce spinal cord compression symptoms. Recently, an increasing number of medical reports have implicated osteoporotic fractures as a cause of serious neurological deficit and painful disabling spinal deformities. This has been corroborated by the present authors as well. These complications are only amenable to surgical management, requiring instrumentation. Instrumenting an osteoporotic spine, although a challenging task, can be accomplished if certain guidelines for surgical techniques are respected. Neurological deficits respond equally well to an anterior or posterior decompression, provided this is coupled with multisegmental fixation of the construct. With the steady increase in the elderly population, it is anticipated that the spine surgeon will face serious complications of osteoporotic spines more frequently. With regard to surgery, however, excellent correction of deformities can be achieved, by combining anterior and posterior approaches. Paget's disease of bone (PD) is a non-hormonal osteometabolic disorder and the spine is the second most commonly affected site. About one-third of patients with spinal involvement exhibit symptoms of clinical stenosis. In only 12-24% of patients with PD of the spine is back pain attributed solely to PD, while in the majority of patients, back pain is either arthritic in nature or a combination of a pagetic process and coexisting arthritis. In this context, one must be certain before attributing low back pain to PD exclusively, and antipagetic medical treatment alone may be ineffective. Neural element dysfunction may be attributed to compressive myelopathy by pagetic bone overgrowth, pagetic intraspinal soft tissue overgrowth, ossification of epidural fat, platybasia, spontaneous bleeding, sarcomatous degeneration and vertebral fracture or subluxation. Neural dysfunction can also result from spinal ischemia when blood is diverted by the so-called "arterial steal syndrome". Because the effectiveness of pharmacologic treatment for pagetic spinal stenosis has been clearly demonstrated, surgical decompression should only be instituted after failure of antipagetic medical treatment. Surgery is indicated as a primary treatment when neural compression is secondary to pathologic fractures, dislocations, spontaneous epidural hematoma, syringomyelia, platybasia, or sarcomatous transformation. Five classes of drugs are available for the treatment of PD. Bisphosphonates are the most popular antipagetic drug and several forms have been investigated.